Merge 5.10.133 into android12-5.10-lts

Changes in 5.10.133
	KVM/VMX: Use TEST %REG,%REG instead of CMP $0,%REG in vmenter.SKVM/nVMX: Use __vmx_vcpu_run in nested_vmx_check_vmentry_hw
	objtool: Refactor ORC section generation
	objtool: Add 'alt_group' struct
	objtool: Support stack layout changes in alternatives
	objtool: Support retpoline jump detection for vmlinux.o
	objtool: Assume only ELF functions do sibling calls
	objtool: Combine UNWIND_HINT_RET_OFFSET and UNWIND_HINT_FUNC
	x86/xen: Support objtool validation in xen-asm.S
	x86/xen: Support objtool vmlinux.o validation in xen-head.S
	x86/alternative: Merge include files
	x86/alternative: Support not-feature
	x86/alternative: Support ALTERNATIVE_TERNARY
	x86/alternative: Use ALTERNATIVE_TERNARY() in _static_cpu_has()
	x86/insn: Rename insn_decode() to insn_decode_from_regs()
	x86/insn: Add a __ignore_sync_check__ marker
	x86/insn: Add an insn_decode() API
	x86/insn-eval: Handle return values from the decoder
	x86/alternative: Use insn_decode()
	x86: Add insn_decode_kernel()
	x86/alternatives: Optimize optimize_nops()
	x86/retpoline: Simplify retpolines
	objtool: Correctly handle retpoline thunk calls
	objtool: Handle per arch retpoline naming
	objtool: Rework the elf_rebuild_reloc_section() logic
	objtool: Add elf_create_reloc() helper
	objtool: Create reloc sections implicitly
	objtool: Extract elf_strtab_concat()
	objtool: Extract elf_symbol_add()
	objtool: Add elf_create_undef_symbol()
	objtool: Keep track of retpoline call sites
	objtool: Cache instruction relocs
	objtool: Skip magical retpoline .altinstr_replacement
	objtool/x86: Rewrite retpoline thunk calls
	objtool: Support asm jump tables
	x86/alternative: Optimize single-byte NOPs at an arbitrary position
	objtool: Fix .symtab_shndx handling for elf_create_undef_symbol()
	objtool: Only rewrite unconditional retpoline thunk calls
	objtool/x86: Ignore __x86_indirect_alt_* symbols
	objtool: Don't make .altinstructions writable
	objtool: Teach get_alt_entry() about more relocation types
	objtool: print out the symbol type when complaining about it
	objtool: Remove reloc symbol type checks in get_alt_entry()
	objtool: Make .altinstructions section entry size consistent
	objtool: Introduce CFI hash
	objtool: Handle __sanitize_cov*() tail calls
	objtool: Classify symbols
	objtool: Explicitly avoid self modifying code in .altinstr_replacement
	objtool,x86: Replace alternatives with .retpoline_sites
	x86/retpoline: Remove unused replacement symbols
	x86/asm: Fix register order
	x86/asm: Fixup odd GEN-for-each-reg.h usage
	x86/retpoline: Move the retpoline thunk declarations to nospec-branch.h
	x86/retpoline: Create a retpoline thunk array
	x86/alternative: Implement .retpoline_sites support
	x86/alternative: Handle Jcc __x86_indirect_thunk_\reg
	x86/alternative: Try inline spectre_v2=retpoline,amd
	x86/alternative: Add debug prints to apply_retpolines()
	bpf,x86: Simplify computing label offsets
	bpf,x86: Respect X86_FEATURE_RETPOLINE*
	x86/lib/atomic64_386_32: Rename things
	x86: Prepare asm files for straight-line-speculation
	x86: Prepare inline-asm for straight-line-speculation
	x86/alternative: Relax text_poke_bp() constraint
	objtool: Add straight-line-speculation validation
	x86: Add straight-line-speculation mitigation
	tools arch: Update arch/x86/lib/mem{cpy,set}_64.S copies used in 'perf bench mem memcpy'
	kvm/emulate: Fix SETcc emulation function offsets with SLS
	objtool: Default ignore INT3 for unreachable
	crypto: x86/poly1305 - Fixup SLS
	objtool: Fix SLS validation for kcov tail-call replacement
	objtool: Fix code relocs vs weak symbols
	objtool: Fix type of reloc::addend
	objtool: Fix symbol creation
	x86/entry: Remove skip_r11rcx
	objtool: Fix objtool regression on x32 systems
	x86/realmode: build with -D__DISABLE_EXPORTS
	x86/kvm/vmx: Make noinstr clean
	x86/cpufeatures: Move RETPOLINE flags to word 11
	x86/retpoline: Cleanup some #ifdefery
	x86/retpoline: Swizzle retpoline thunk
	Makefile: Set retpoline cflags based on CONFIG_CC_IS_{CLANG,GCC}
	x86/retpoline: Use -mfunction-return
	x86: Undo return-thunk damage
	x86,objtool: Create .return_sites
	objtool: skip non-text sections when adding return-thunk sites
	x86,static_call: Use alternative RET encoding
	x86/ftrace: Use alternative RET encoding
	x86/bpf: Use alternative RET encoding
	x86/kvm: Fix SETcc emulation for return thunks
	x86/vsyscall_emu/64: Don't use RET in vsyscall emulation
	x86/sev: Avoid using __x86_return_thunk
	x86: Use return-thunk in asm code
	objtool: Treat .text.__x86.* as noinstr
	x86: Add magic AMD return-thunk
	x86/bugs: Report AMD retbleed vulnerability
	x86/bugs: Add AMD retbleed= boot parameter
	x86/bugs: Enable STIBP for JMP2RET
	x86/bugs: Keep a per-CPU IA32_SPEC_CTRL value
	x86/entry: Add kernel IBRS implementation
	x86/bugs: Optimize SPEC_CTRL MSR writes
	x86/speculation: Add spectre_v2=ibrs option to support Kernel IBRS
	x86/bugs: Split spectre_v2_select_mitigation() and spectre_v2_user_select_mitigation()
	x86/bugs: Report Intel retbleed vulnerability
	intel_idle: Disable IBRS during long idle
	objtool: Update Retpoline validation
	x86/xen: Rename SYS* entry points
	x86/bugs: Add retbleed=ibpb
	x86/bugs: Do IBPB fallback check only once
	objtool: Add entry UNRET validation
	x86/cpu/amd: Add Spectral Chicken
	x86/speculation: Fix RSB filling with CONFIG_RETPOLINE=n
	x86/speculation: Fix firmware entry SPEC_CTRL handling
	x86/speculation: Fix SPEC_CTRL write on SMT state change
	x86/speculation: Use cached host SPEC_CTRL value for guest entry/exit
	x86/speculation: Remove x86_spec_ctrl_mask
	objtool: Re-add UNWIND_HINT_{SAVE_RESTORE}
	KVM: VMX: Flatten __vmx_vcpu_run()
	KVM: VMX: Convert launched argument to flags
	KVM: VMX: Prevent guest RSB poisoning attacks with eIBRS
	KVM: VMX: Fix IBRS handling after vmexit
	x86/speculation: Fill RSB on vmexit for IBRS
	x86/common: Stamp out the stepping madness
	x86/cpu/amd: Enumerate BTC_NO
	x86/retbleed: Add fine grained Kconfig knobs
	x86/bugs: Add Cannon lake to RETBleed affected CPU list
	x86/bugs: Do not enable IBPB-on-entry when IBPB is not supported
	x86/kexec: Disable RET on kexec
	x86/speculation: Disable RRSBA behavior
	x86/static_call: Serialize __static_call_fixup() properly
	tools/insn: Restore the relative include paths for cross building
	x86, kvm: use proper ASM macros for kvm_vcpu_is_preempted
	x86/xen: Fix initialisation in hypercall_page after rethunk
	x86/ftrace: Add UNWIND_HINT_FUNC annotation for ftrace_stub
	x86/asm/32: Fix ANNOTATE_UNRET_SAFE use on 32-bit
	x86/speculation: Use DECLARE_PER_CPU for x86_spec_ctrl_current
	efi/x86: use naked RET on mixed mode call wrapper
	x86/kvm: fix FASTOP_SIZE when return thunks are enabled
	KVM: emulate: do not adjust size of fastop and setcc subroutines
	tools arch x86: Sync the msr-index.h copy with the kernel sources
	tools headers cpufeatures: Sync with the kernel sources
	x86/bugs: Remove apostrophe typo
	um: Add missing apply_returns()
	x86: Use -mindirect-branch-cs-prefix for RETPOLINE builds
	kvm: fix objtool relocation warning
	objtool: Fix elf_create_undef_symbol() endianness
	tools arch: Update arch/x86/lib/mem{cpy,set}_64.S copies used in 'perf bench mem memcpy' - again
	tools headers: Remove broken definition of __LITTLE_ENDIAN
	Linux 5.10.133

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Change-Id: I7e23843058c509562ae3f3a68e0710f31249a087

Documentation/admin-guide/kernel-parameters.txt

@@ -4751,6 +4751,30 @@
 
 	retain_initrd	[RAM] Keep initrd memory after extraction
 
+	retbleed=	[X86] Control mitigation of RETBleed (Arbitrary
+			Speculative Code Execution with Return Instructions)
+			vulnerability.
+
+			off          - no mitigation
+			auto         - automatically select a migitation
+			auto,nosmt   - automatically select a mitigation,
+				       disabling SMT if necessary for
+				       the full mitigation (only on Zen1
+				       and older without STIBP).
+			ibpb	     - mitigate short speculation windows on
+				       basic block boundaries too. Safe, highest
+				       perf impact.
+			unret        - force enable untrained return thunks,
+				       only effective on AMD f15h-f17h
+				       based systems.
+			unret,nosmt  - like unret, will disable SMT when STIBP
+			               is not available.
+
+			Selecting 'auto' will choose a mitigation method at run
+			time according to the CPU.
+
+			Not specifying this option is equivalent to retbleed=auto.
+
 	rfkill.default_state=
 		0	"airplane mode".  All wifi, bluetooth, wimax, gps, fm,
 			etc. communication is blocked by default.
@@ -5100,6 +5124,7 @@
 			eibrs		  - enhanced IBRS
 			eibrs,retpoline   - enhanced IBRS + Retpolines
 			eibrs,lfence      - enhanced IBRS + LFENCE
+			ibrs		  - use IBRS to protect kernel
 
 			Not specifying this option is equivalent to
 			spectre_v2=auto.

Makefile

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 VERSION = 5
 PATCHLEVEL = 10
-SUBLEVEL = 132
+SUBLEVEL = 133
 EXTRAVERSION =
 NAME = Dare mighty things
 
@@ -688,12 +688,21 @@ ifdef CONFIG_FUNCTION_TRACER
   CC_FLAGS_FTRACE := -pg
 endif
 
-RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
+ifdef CONFIG_CC_IS_GCC
-RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
+RETPOLINE_CFLAGS	:= $(call cc-option,-mindirect-branch=thunk-extern -mindirect-branch-register)
-RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
+RETPOLINE_CFLAGS	+= $(call cc-option,-mindirect-branch-cs-prefix)
-RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
+RETPOLINE_VDSO_CFLAGS	:= $(call cc-option,-mindirect-branch=thunk-inline -mindirect-branch-register)
-RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
+endif
-RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
+ifdef CONFIG_CC_IS_CLANG
+RETPOLINE_CFLAGS	:= -mretpoline-external-thunk
+RETPOLINE_VDSO_CFLAGS	:= -mretpoline
+endif
+
+ifdef CONFIG_RETHUNK
+RETHUNK_CFLAGS         := -mfunction-return=thunk-extern
+RETPOLINE_CFLAGS       += $(RETHUNK_CFLAGS)
+endif
+
 export RETPOLINE_CFLAGS
 export RETPOLINE_VDSO_CFLAGS
 

arch/um/kernel/um_arch.c

@@ -358,6 +358,14 @@ void __init check_bugs(void)
 	os_check_bugs();
 }
 
+void apply_retpolines(s32 *start, s32 *end)
+{
+}
+
+void apply_returns(s32 *start, s32 *end)
+{
+}
+
 void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
 {
 }

arch/x86/Kconfig

@@ -460,15 +460,6 @@ config GOLDFISH
 	def_bool y
 	depends on X86_GOLDFISH
 
-config RETPOLINE
-	bool "Avoid speculative indirect branches in kernel"
-	default y
-	help
-	  Compile kernel with the retpoline compiler options to guard against
-	  kernel-to-user data leaks by avoiding speculative indirect
-	  branches. Requires a compiler with -mindirect-branch=thunk-extern
-	  support for full protection. The kernel may run slower.
-
 config X86_CPU_RESCTRL
 	bool "x86 CPU resource control support"
 	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
@@ -2422,6 +2413,88 @@ source "kernel/livepatch/Kconfig"
 
 endmenu
 
+config CC_HAS_SLS
+	def_bool $(cc-option,-mharden-sls=all)
+
+config CC_HAS_RETURN_THUNK
+	def_bool $(cc-option,-mfunction-return=thunk-extern)
+
+menuconfig SPECULATION_MITIGATIONS
+	bool "Mitigations for speculative execution vulnerabilities"
+	default y
+	help
+	  Say Y here to enable options which enable mitigations for
+	  speculative execution hardware vulnerabilities.
+
+	  If you say N, all mitigations will be disabled. You really
+	  should know what you are doing to say so.
+
+if SPECULATION_MITIGATIONS
+
+config PAGE_TABLE_ISOLATION
+	bool "Remove the kernel mapping in user mode"
+	default y
+	depends on (X86_64 || X86_PAE)
+	help
+	  This feature reduces the number of hardware side channels by
+	  ensuring that the majority of kernel addresses are not mapped
+	  into userspace.
+
+	  See Documentation/x86/pti.rst for more details.
+
+config RETPOLINE
+	bool "Avoid speculative indirect branches in kernel"
+	default y
+	help
+	  Compile kernel with the retpoline compiler options to guard against
+	  kernel-to-user data leaks by avoiding speculative indirect
+	  branches. Requires a compiler with -mindirect-branch=thunk-extern
+	  support for full protection. The kernel may run slower.
+
+config RETHUNK
+	bool "Enable return-thunks"
+	depends on RETPOLINE && CC_HAS_RETURN_THUNK
+	default y
+	help
+	  Compile the kernel with the return-thunks compiler option to guard
+	  against kernel-to-user data leaks by avoiding return speculation.
+	  Requires a compiler with -mfunction-return=thunk-extern
+	  support for full protection. The kernel may run slower.
+
+config CPU_UNRET_ENTRY
+	bool "Enable UNRET on kernel entry"
+	depends on CPU_SUP_AMD && RETHUNK
+	default y
+	help
+	  Compile the kernel with support for the retbleed=unret mitigation.
+
+config CPU_IBPB_ENTRY
+	bool "Enable IBPB on kernel entry"
+	depends on CPU_SUP_AMD
+	default y
+	help
+	  Compile the kernel with support for the retbleed=ibpb mitigation.
+
+config CPU_IBRS_ENTRY
+	bool "Enable IBRS on kernel entry"
+	depends on CPU_SUP_INTEL
+	default y
+	help
+	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
+	  This mitigates both spectre_v2 and retbleed at great cost to
+	  performance.
+
+config SLS
+	bool "Mitigate Straight-Line-Speculation"
+	depends on CC_HAS_SLS && X86_64
+	default n
+	help
+	  Compile the kernel with straight-line-speculation options to guard
+	  against straight line speculation. The kernel image might be slightly
+	  larger.
+
+endif
+
 config ARCH_HAS_ADD_PAGES
 	def_bool y
 	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG

arch/x86/Makefile

@@ -31,7 +31,7 @@ endif
 CODE16GCC_CFLAGS := -m32 -Wa,$(srctree)/arch/x86/boot/code16gcc.h
 M16_CFLAGS	 := $(call cc-option, -m16, $(CODE16GCC_CFLAGS))
 
-REALMODE_CFLAGS	:= $(M16_CFLAGS) -g -Os -DDISABLE_BRANCH_PROFILING \
+REALMODE_CFLAGS	:= $(M16_CFLAGS) -g -Os -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS \
 		   -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \
 		   -fno-strict-aliasing -fomit-frame-pointer -fno-pic \
 		   -mno-mmx -mno-sse $(call cc-option,-fcf-protection=none)
@@ -196,6 +196,10 @@ ifdef CONFIG_RETPOLINE
   endif
 endif
 
+ifdef CONFIG_SLS
+  KBUILD_CFLAGS += -mharden-sls=all
+endif
+
 KBUILD_LDFLAGS += -m elf_$(UTS_MACHINE)
 
 ifdef CONFIG_LTO_CLANG

arch/x86/boot/compressed/efi_thunk_64.S

@@ -89,7 +89,7 @@ SYM_FUNC_START(__efi64_thunk)
 
 	pop	%rbx
 	pop	%rbp
-	ret
+	RET
 SYM_FUNC_END(__efi64_thunk)
 
 	.code32

arch/x86/boot/compressed/head_64.S

@@ -786,7 +786,7 @@ SYM_FUNC_START(efi32_pe_entry)
 2:	popl	%edi				// restore callee-save registers
 	popl	%ebx
 	leave
-	ret
+	RET
 SYM_FUNC_END(efi32_pe_entry)
 
 	.section ".rodata"
@@ -868,7 +868,7 @@ SYM_FUNC_START(startup32_check_sev_cbit)
 	popl	%ebx
 	popl	%eax
 #endif
-	ret
+	RET
 SYM_FUNC_END(startup32_check_sev_cbit)
 
 /*

arch/x86/boot/compressed/mem_encrypt.S

@@ -58,7 +58,7 @@ SYM_FUNC_START(get_sev_encryption_bit)
 
 #endif	/* CONFIG_AMD_MEM_ENCRYPT */
 
-	ret
+	RET
 SYM_FUNC_END(get_sev_encryption_bit)
 
 	.code64
@@ -99,7 +99,7 @@ SYM_FUNC_START(set_sev_encryption_mask)
 #endif
 
 	xor	%rax, %rax
-	ret
+	RET
 SYM_FUNC_END(set_sev_encryption_mask)
 
 	.data

arch/x86/crypto/aegis128-aesni-asm.S

@@ -122,7 +122,7 @@ SYM_FUNC_START_LOCAL(__load_partial)
 	pxor T0, MSG
 
 .Lld_partial_8:
-	ret
+	RET
 SYM_FUNC_END(__load_partial)
 
 /*
@@ -180,7 +180,7 @@ SYM_FUNC_START_LOCAL(__store_partial)
 	mov %r10b, (%r9)
 
 .Lst_partial_1:
-	ret
+	RET
 SYM_FUNC_END(__store_partial)
 
 /*
@@ -225,7 +225,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_init)
 	movdqu STATE4, 0x40(STATEP)
 
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(crypto_aegis128_aesni_init)
 
 /*
@@ -337,7 +337,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_ad)
 	movdqu STATE3, 0x30(STATEP)
 	movdqu STATE4, 0x40(STATEP)
 	FRAME_END
-	ret
+	RET
 
 .Lad_out_1:
 	movdqu STATE4, 0x00(STATEP)
@@ -346,7 +346,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_ad)
 	movdqu STATE2, 0x30(STATEP)
 	movdqu STATE3, 0x40(STATEP)
 	FRAME_END
-	ret
+	RET
 
 .Lad_out_2:
 	movdqu STATE3, 0x00(STATEP)
@@ -355,7 +355,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_ad)
 	movdqu STATE1, 0x30(STATEP)
 	movdqu STATE2, 0x40(STATEP)
 	FRAME_END
-	ret
+	RET
 
 .Lad_out_3:
 	movdqu STATE2, 0x00(STATEP)
@@ -364,7 +364,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_ad)
 	movdqu STATE0, 0x30(STATEP)
 	movdqu STATE1, 0x40(STATEP)
 	FRAME_END
-	ret
+	RET
 
 .Lad_out_4:
 	movdqu STATE1, 0x00(STATEP)
@@ -373,11 +373,11 @@ SYM_FUNC_START(crypto_aegis128_aesni_ad)
 	movdqu STATE4, 0x30(STATEP)
 	movdqu STATE0, 0x40(STATEP)
 	FRAME_END
-	ret
+	RET
 
 .Lad_out:
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(crypto_aegis128_aesni_ad)
 
 .macro encrypt_block a s0 s1 s2 s3 s4 i
@@ -452,7 +452,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_enc)
 	movdqu STATE2, 0x30(STATEP)
 	movdqu STATE3, 0x40(STATEP)
 	FRAME_END
-	ret
+	RET
 
 .Lenc_out_1:
 	movdqu STATE3, 0x00(STATEP)
@@ -461,7 +461,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_enc)
 	movdqu STATE1, 0x30(STATEP)
 	movdqu STATE2, 0x40(STATEP)
 	FRAME_END
-	ret
+	RET
 
 .Lenc_out_2:
 	movdqu STATE2, 0x00(STATEP)
@@ -470,7 +470,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_enc)
 	movdqu STATE0, 0x30(STATEP)
 	movdqu STATE1, 0x40(STATEP)
 	FRAME_END
-	ret
+	RET
 
 .Lenc_out_3:
 	movdqu STATE1, 0x00(STATEP)
@@ -479,7 +479,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_enc)
 	movdqu STATE4, 0x30(STATEP)
 	movdqu STATE0, 0x40(STATEP)
 	FRAME_END
-	ret
+	RET
 
 .Lenc_out_4:
 	movdqu STATE0, 0x00(STATEP)
@@ -488,11 +488,11 @@ SYM_FUNC_START(crypto_aegis128_aesni_enc)
 	movdqu STATE3, 0x30(STATEP)
 	movdqu STATE4, 0x40(STATEP)
 	FRAME_END
-	ret
+	RET
 
 .Lenc_out:
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(crypto_aegis128_aesni_enc)
 
 /*
@@ -532,7 +532,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_enc_tail)
 	movdqu STATE3, 0x40(STATEP)
 
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(crypto_aegis128_aesni_enc_tail)
 
 .macro decrypt_block a s0 s1 s2 s3 s4 i
@@ -606,7 +606,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_dec)
 	movdqu STATE2, 0x30(STATEP)
 	movdqu STATE3, 0x40(STATEP)
 	FRAME_END
-	ret
+	RET
 
 .Ldec_out_1:
 	movdqu STATE3, 0x00(STATEP)
@@ -615,7 +615,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_dec)
 	movdqu STATE1, 0x30(STATEP)
 	movdqu STATE2, 0x40(STATEP)
 	FRAME_END
-	ret
+	RET
 
 .Ldec_out_2:
 	movdqu STATE2, 0x00(STATEP)
@@ -624,7 +624,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_dec)
 	movdqu STATE0, 0x30(STATEP)
 	movdqu STATE1, 0x40(STATEP)
 	FRAME_END
-	ret
+	RET
 
 .Ldec_out_3:
 	movdqu STATE1, 0x00(STATEP)
@@ -633,7 +633,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_dec)
 	movdqu STATE4, 0x30(STATEP)
 	movdqu STATE0, 0x40(STATEP)
 	FRAME_END
-	ret
+	RET
 
 .Ldec_out_4:
 	movdqu STATE0, 0x00(STATEP)
@@ -642,11 +642,11 @@ SYM_FUNC_START(crypto_aegis128_aesni_dec)
 	movdqu STATE3, 0x30(STATEP)
 	movdqu STATE4, 0x40(STATEP)
 	FRAME_END
-	ret
+	RET
 
 .Ldec_out:
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(crypto_aegis128_aesni_dec)
 
 /*
@@ -696,7 +696,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_dec_tail)
 	movdqu STATE3, 0x40(STATEP)
 
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(crypto_aegis128_aesni_dec_tail)
 
 /*
@@ -743,5 +743,5 @@ SYM_FUNC_START(crypto_aegis128_aesni_final)
 	movdqu MSG, (%rsi)
 
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(crypto_aegis128_aesni_final)

arch/x86/crypto/aes_ctrby8_avx-x86_64.S

@@ -525,7 +525,7 @@ ddq_add_8:
 	/* return updated IV */
 	vpshufb	xbyteswap, xcounter, xcounter
 	vmovdqu	xcounter, (p_iv)
-	ret
+	RET
 .endm
 
 /*

arch/x86/crypto/aesni-intel_asm.S

@@ -1598,7 +1598,7 @@ SYM_FUNC_START(aesni_gcm_dec)
 	GCM_ENC_DEC dec
 	GCM_COMPLETE arg10, arg11
 	FUNC_RESTORE
-	ret
+	RET
 SYM_FUNC_END(aesni_gcm_dec)
 
 
@@ -1687,7 +1687,7 @@ SYM_FUNC_START(aesni_gcm_enc)
 
 	GCM_COMPLETE arg10, arg11
 	FUNC_RESTORE
-	ret
+	RET
 SYM_FUNC_END(aesni_gcm_enc)
 
 /*****************************************************************************
@@ -1705,7 +1705,7 @@ SYM_FUNC_START(aesni_gcm_init)
 	FUNC_SAVE
 	GCM_INIT %arg3, %arg4,%arg5, %arg6
 	FUNC_RESTORE
-	ret
+	RET
 SYM_FUNC_END(aesni_gcm_init)
 
 /*****************************************************************************
@@ -1720,7 +1720,7 @@ SYM_FUNC_START(aesni_gcm_enc_update)
 	FUNC_SAVE
 	GCM_ENC_DEC enc
 	FUNC_RESTORE
-	ret
+	RET
 SYM_FUNC_END(aesni_gcm_enc_update)
 
 /*****************************************************************************
@@ -1735,7 +1735,7 @@ SYM_FUNC_START(aesni_gcm_dec_update)
 	FUNC_SAVE
 	GCM_ENC_DEC dec
 	FUNC_RESTORE
-	ret
+	RET
 SYM_FUNC_END(aesni_gcm_dec_update)
 
 /*****************************************************************************
@@ -1750,7 +1750,7 @@ SYM_FUNC_START(aesni_gcm_finalize)
 	FUNC_SAVE
 	GCM_COMPLETE %arg3 %arg4
 	FUNC_RESTORE
-	ret
+	RET
 SYM_FUNC_END(aesni_gcm_finalize)
 
 #endif
@@ -1766,7 +1766,7 @@ SYM_FUNC_START_LOCAL(_key_expansion_256a)
 	pxor %xmm1, %xmm0
 	movaps %xmm0, (TKEYP)
 	add $0x10, TKEYP
-	ret
+	RET
 SYM_FUNC_END(_key_expansion_256a)
 SYM_FUNC_END_ALIAS(_key_expansion_128)
 
@@ -1791,7 +1791,7 @@ SYM_FUNC_START_LOCAL(_key_expansion_192a)
 	shufps $0b01001110, %xmm2, %xmm1
 	movaps %xmm1, 0x10(TKEYP)
 	add $0x20, TKEYP
-	ret
+	RET
 SYM_FUNC_END(_key_expansion_192a)
 
 SYM_FUNC_START_LOCAL(_key_expansion_192b)
@@ -1810,7 +1810,7 @@ SYM_FUNC_START_LOCAL(_key_expansion_192b)
 
 	movaps %xmm0, (TKEYP)
 	add $0x10, TKEYP
-	ret
+	RET
 SYM_FUNC_END(_key_expansion_192b)
 
 SYM_FUNC_START_LOCAL(_key_expansion_256b)
@@ -1822,7 +1822,7 @@ SYM_FUNC_START_LOCAL(_key_expansion_256b)
 	pxor %xmm1, %xmm2
 	movaps %xmm2, (TKEYP)
 	add $0x10, TKEYP
-	ret
+	RET
 SYM_FUNC_END(_key_expansion_256b)
 
 /*
@@ -1937,7 +1937,7 @@ SYM_FUNC_START(aesni_set_key)
 	popl KEYP
 #endif
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(aesni_set_key)
 
 /*
@@ -1961,7 +1961,7 @@ SYM_FUNC_START(aesni_enc)
 	popl KEYP
 #endif
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(aesni_enc)
 
 /*
@@ -2018,7 +2018,7 @@ SYM_FUNC_START_LOCAL(_aesni_enc1)
 	aesenc KEY, STATE
 	movaps 0x70(TKEYP), KEY
 	aesenclast KEY, STATE
-	ret
+	RET
 SYM_FUNC_END(_aesni_enc1)
 
 /*
@@ -2126,7 +2126,7 @@ SYM_FUNC_START_LOCAL(_aesni_enc4)
 	aesenclast KEY, STATE2
 	aesenclast KEY, STATE3
 	aesenclast KEY, STATE4
-	ret
+	RET
 SYM_FUNC_END(_aesni_enc4)
 
 /*
@@ -2151,7 +2151,7 @@ SYM_FUNC_START(aesni_dec)
 	popl KEYP
 #endif
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(aesni_dec)
 
 /*
@@ -2208,7 +2208,7 @@ SYM_FUNC_START_LOCAL(_aesni_dec1)
 	aesdec KEY, STATE
 	movaps 0x70(TKEYP), KEY
 	aesdeclast KEY, STATE
-	ret
+	RET
 SYM_FUNC_END(_aesni_dec1)
 
 /*
@@ -2316,7 +2316,7 @@ SYM_FUNC_START_LOCAL(_aesni_dec4)
 	aesdeclast KEY, STATE2
 	aesdeclast KEY, STATE3
 	aesdeclast KEY, STATE4
-	ret
+	RET
 SYM_FUNC_END(_aesni_dec4)
 
 /*
@@ -2376,7 +2376,7 @@ SYM_FUNC_START(aesni_ecb_enc)
 	popl LEN
 #endif
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(aesni_ecb_enc)
 
 /*
@@ -2437,7 +2437,7 @@ SYM_FUNC_START(aesni_ecb_dec)
 	popl LEN
 #endif
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(aesni_ecb_dec)
 
 /*
@@ -2481,7 +2481,7 @@ SYM_FUNC_START(aesni_cbc_enc)
 	popl IVP
 #endif
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(aesni_cbc_enc)
 
 /*
@@ -2574,7 +2574,7 @@ SYM_FUNC_START(aesni_cbc_dec)
 	popl IVP
 #endif
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(aesni_cbc_dec)
 
 #ifdef __x86_64__
@@ -2602,7 +2602,7 @@ SYM_FUNC_START_LOCAL(_aesni_inc_init)
 	mov $1, TCTR_LOW
 	movq TCTR_LOW, INC
 	movq CTR, TCTR_LOW
-	ret
+	RET
 SYM_FUNC_END(_aesni_inc_init)
 
 /*
@@ -2630,7 +2630,7 @@ SYM_FUNC_START_LOCAL(_aesni_inc)
 .Linc_low:
 	movaps CTR, IV
 	pshufb BSWAP_MASK, IV
-	ret
+	RET
 SYM_FUNC_END(_aesni_inc)
 
 /*
@@ -2693,7 +2693,7 @@ SYM_FUNC_START(aesni_ctr_enc)
 	movups IV, (IVP)
 .Lctr_enc_just_ret:
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(aesni_ctr_enc)
 
 /*
@@ -2778,7 +2778,7 @@ SYM_FUNC_START(aesni_xts_encrypt)
 	movups IV, (IVP)
 
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(aesni_xts_encrypt)
 
 /*
@@ -2846,7 +2846,7 @@ SYM_FUNC_START(aesni_xts_decrypt)
 	movups IV, (IVP)
 
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(aesni_xts_decrypt)
 
 #endif

arch/x86/crypto/aesni-intel_avx-x86_64.S

@@ -1777,7 +1777,7 @@ SYM_FUNC_START(aesni_gcm_init_avx_gen2)
         FUNC_SAVE
         INIT GHASH_MUL_AVX, PRECOMPUTE_AVX
         FUNC_RESTORE
-        ret
+        RET
 SYM_FUNC_END(aesni_gcm_init_avx_gen2)
 
 ###############################################################################
@@ -1798,15 +1798,15 @@ SYM_FUNC_START(aesni_gcm_enc_update_avx_gen2)
         # must be 192
         GCM_ENC_DEC INITIAL_BLOCKS_AVX, GHASH_8_ENCRYPT_8_PARALLEL_AVX, GHASH_LAST_8_AVX, GHASH_MUL_AVX, ENC, 11
         FUNC_RESTORE
-        ret
+        RET
 key_128_enc_update:
         GCM_ENC_DEC INITIAL_BLOCKS_AVX, GHASH_8_ENCRYPT_8_PARALLEL_AVX, GHASH_LAST_8_AVX, GHASH_MUL_AVX, ENC, 9
         FUNC_RESTORE
-        ret
+        RET
 key_256_enc_update:
         GCM_ENC_DEC INITIAL_BLOCKS_AVX, GHASH_8_ENCRYPT_8_PARALLEL_AVX, GHASH_LAST_8_AVX, GHASH_MUL_AVX, ENC, 13
         FUNC_RESTORE
-        ret
+        RET
 SYM_FUNC_END(aesni_gcm_enc_update_avx_gen2)
 
 ###############################################################################
@@ -1827,15 +1827,15 @@ SYM_FUNC_START(aesni_gcm_dec_update_avx_gen2)
         # must be 192
         GCM_ENC_DEC INITIAL_BLOCKS_AVX, GHASH_8_ENCRYPT_8_PARALLEL_AVX, GHASH_LAST_8_AVX, GHASH_MUL_AVX, DEC, 11
         FUNC_RESTORE
-        ret
+        RET
 key_128_dec_update:
         GCM_ENC_DEC INITIAL_BLOCKS_AVX, GHASH_8_ENCRYPT_8_PARALLEL_AVX, GHASH_LAST_8_AVX, GHASH_MUL_AVX, DEC, 9
         FUNC_RESTORE
-        ret
+        RET
 key_256_dec_update:
         GCM_ENC_DEC INITIAL_BLOCKS_AVX, GHASH_8_ENCRYPT_8_PARALLEL_AVX, GHASH_LAST_8_AVX, GHASH_MUL_AVX, DEC, 13
         FUNC_RESTORE
-        ret
+        RET
 SYM_FUNC_END(aesni_gcm_dec_update_avx_gen2)
 
 ###############################################################################
@@ -1856,15 +1856,15 @@ SYM_FUNC_START(aesni_gcm_finalize_avx_gen2)
         # must be 192
         GCM_COMPLETE GHASH_MUL_AVX, 11, arg3, arg4
         FUNC_RESTORE
-        ret
+        RET
 key_128_finalize:
         GCM_COMPLETE GHASH_MUL_AVX, 9, arg3, arg4
         FUNC_RESTORE
-        ret
+        RET
 key_256_finalize:
         GCM_COMPLETE GHASH_MUL_AVX, 13, arg3, arg4
         FUNC_RESTORE
-        ret
+        RET
 SYM_FUNC_END(aesni_gcm_finalize_avx_gen2)
 
 ###############################################################################
@@ -2745,7 +2745,7 @@ SYM_FUNC_START(aesni_gcm_init_avx_gen4)
         FUNC_SAVE
         INIT GHASH_MUL_AVX2, PRECOMPUTE_AVX2
         FUNC_RESTORE
-        ret
+        RET
 SYM_FUNC_END(aesni_gcm_init_avx_gen4)
 
 ###############################################################################
@@ -2766,15 +2766,15 @@ SYM_FUNC_START(aesni_gcm_enc_update_avx_gen4)
         # must be 192
         GCM_ENC_DEC INITIAL_BLOCKS_AVX2, GHASH_8_ENCRYPT_8_PARALLEL_AVX2, GHASH_LAST_8_AVX2, GHASH_MUL_AVX2, ENC, 11
         FUNC_RESTORE
-	ret
+	RET
 key_128_enc_update4:
         GCM_ENC_DEC INITIAL_BLOCKS_AVX2, GHASH_8_ENCRYPT_8_PARALLEL_AVX2, GHASH_LAST_8_AVX2, GHASH_MUL_AVX2, ENC, 9
         FUNC_RESTORE
-	ret
+	RET
 key_256_enc_update4:
         GCM_ENC_DEC INITIAL_BLOCKS_AVX2, GHASH_8_ENCRYPT_8_PARALLEL_AVX2, GHASH_LAST_8_AVX2, GHASH_MUL_AVX2, ENC, 13
         FUNC_RESTORE
-	ret
+	RET
 SYM_FUNC_END(aesni_gcm_enc_update_avx_gen4)
 
 ###############################################################################
@@ -2795,15 +2795,15 @@ SYM_FUNC_START(aesni_gcm_dec_update_avx_gen4)
         # must be 192
         GCM_ENC_DEC INITIAL_BLOCKS_AVX2, GHASH_8_ENCRYPT_8_PARALLEL_AVX2, GHASH_LAST_8_AVX2, GHASH_MUL_AVX2, DEC, 11
         FUNC_RESTORE
-        ret
+        RET
 key_128_dec_update4:
         GCM_ENC_DEC INITIAL_BLOCKS_AVX2, GHASH_8_ENCRYPT_8_PARALLEL_AVX2, GHASH_LAST_8_AVX2, GHASH_MUL_AVX2, DEC, 9
         FUNC_RESTORE
-        ret
+        RET
 key_256_dec_update4:
         GCM_ENC_DEC INITIAL_BLOCKS_AVX2, GHASH_8_ENCRYPT_8_PARALLEL_AVX2, GHASH_LAST_8_AVX2, GHASH_MUL_AVX2, DEC, 13
         FUNC_RESTORE
-        ret
+        RET
 SYM_FUNC_END(aesni_gcm_dec_update_avx_gen4)
 
 ###############################################################################
@@ -2824,13 +2824,13 @@ SYM_FUNC_START(aesni_gcm_finalize_avx_gen4)
         # must be 192
         GCM_COMPLETE GHASH_MUL_AVX2, 11, arg3, arg4
         FUNC_RESTORE
-        ret
+        RET
 key_128_finalize4:
         GCM_COMPLETE GHASH_MUL_AVX2, 9, arg3, arg4
         FUNC_RESTORE
-        ret
+        RET
 key_256_finalize4:
         GCM_COMPLETE GHASH_MUL_AVX2, 13, arg3, arg4
         FUNC_RESTORE
-        ret
+        RET
 SYM_FUNC_END(aesni_gcm_finalize_avx_gen4)

arch/x86/crypto/blake2s-core.S

@@ -171,7 +171,7 @@ SYM_FUNC_START(blake2s_compress_ssse3)
 	movdqu		%xmm1,0x10(%rdi)
 	movdqu		%xmm14,0x20(%rdi)
 .Lendofloop:
-	ret
+	RET
 SYM_FUNC_END(blake2s_compress_ssse3)
 
 #ifdef CONFIG_AS_AVX512
@@ -251,6 +251,6 @@ SYM_FUNC_START(blake2s_compress_avx512)
 	vmovdqu		%xmm1,0x10(%rdi)
 	vmovdqu		%xmm4,0x20(%rdi)
 	vzeroupper
-	retq
+	RET
 SYM_FUNC_END(blake2s_compress_avx512)
 #endif /* CONFIG_AS_AVX512 */

arch/x86/crypto/blowfish-x86_64-asm_64.S

@@ -135,10 +135,10 @@ SYM_FUNC_START(__blowfish_enc_blk)
 	jnz .L__enc_xor;
 
 	write_block();
-	ret;
+	RET;
 .L__enc_xor:
 	xor_block();
-	ret;
+	RET;
 SYM_FUNC_END(__blowfish_enc_blk)
 
 SYM_FUNC_START(blowfish_dec_blk)
@@ -170,7 +170,7 @@ SYM_FUNC_START(blowfish_dec_blk)
 
 	movq %r11, %r12;
 
-	ret;
+	RET;
 SYM_FUNC_END(blowfish_dec_blk)
 
 /**********************************************************************
@@ -322,14 +322,14 @@ SYM_FUNC_START(__blowfish_enc_blk_4way)
 
 	popq %rbx;
 	popq %r12;
-	ret;
+	RET;
 
 .L__enc_xor4:
 	xor_block4();
 
 	popq %rbx;
 	popq %r12;
-	ret;
+	RET;
 SYM_FUNC_END(__blowfish_enc_blk_4way)
 
 SYM_FUNC_START(blowfish_dec_blk_4way)
@@ -364,5 +364,5 @@ SYM_FUNC_START(blowfish_dec_blk_4way)
 	popq %rbx;
 	popq %r12;
 
-	ret;
+	RET;
 SYM_FUNC_END(blowfish_dec_blk_4way)

arch/x86/crypto/camellia-aesni-avx-asm_64.S

@@ -193,7 +193,7 @@ SYM_FUNC_START_LOCAL(roundsm16_x0_x1_x2_x3_x4_x5_x6_x7_y0_y1_y2_y3_y4_y5_y6_y7_c
 	roundsm16(%xmm0, %xmm1, %xmm2, %xmm3, %xmm4, %xmm5, %xmm6, %xmm7,
 		  %xmm8, %xmm9, %xmm10, %xmm11, %xmm12, %xmm13, %xmm14, %xmm15,
 		  %rcx, (%r9));
-	ret;
+	RET;
 SYM_FUNC_END(roundsm16_x0_x1_x2_x3_x4_x5_x6_x7_y0_y1_y2_y3_y4_y5_y6_y7_cd)
 
 .align 8
@@ -201,7 +201,7 @@ SYM_FUNC_START_LOCAL(roundsm16_x4_x5_x6_x7_x0_x1_x2_x3_y4_y5_y6_y7_y0_y1_y2_y3_a
 	roundsm16(%xmm4, %xmm5, %xmm6, %xmm7, %xmm0, %xmm1, %xmm2, %xmm3,
 		  %xmm12, %xmm13, %xmm14, %xmm15, %xmm8, %xmm9, %xmm10, %xmm11,
 		  %rax, (%r9));
-	ret;
+	RET;
 SYM_FUNC_END(roundsm16_x4_x5_x6_x7_x0_x1_x2_x3_y4_y5_y6_y7_y0_y1_y2_y3_ab)
 
 /*
@@ -787,7 +787,7 @@ SYM_FUNC_START_LOCAL(__camellia_enc_blk16)
 		    %xmm15, (key_table)(CTX, %r8, 8), (%rax), 1 * 16(%rax));
 
 	FRAME_END
-	ret;
+	RET;
 
 .align 8
 .Lenc_max32:
@@ -874,7 +874,7 @@ SYM_FUNC_START_LOCAL(__camellia_dec_blk16)
 		    %xmm15, (key_table)(CTX), (%rax), 1 * 16(%rax));
 
 	FRAME_END
-	ret;
+	RET;
 
 .align 8
 .Ldec_max32:
@@ -915,7 +915,7 @@ SYM_FUNC_START(camellia_ecb_enc_16way)
 		     %xmm8, %rsi);
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(camellia_ecb_enc_16way)
 
 SYM_FUNC_START(camellia_ecb_dec_16way)
@@ -945,7 +945,7 @@ SYM_FUNC_START(camellia_ecb_dec_16way)
 		     %xmm8, %rsi);
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(camellia_ecb_dec_16way)
 
 SYM_FUNC_START(camellia_cbc_dec_16way)
@@ -996,7 +996,7 @@ SYM_FUNC_START(camellia_cbc_dec_16way)
 		     %xmm8, %rsi);
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(camellia_cbc_dec_16way)
 
 #define inc_le128(x, minus_one, tmp) \
@@ -1109,7 +1109,7 @@ SYM_FUNC_START(camellia_ctr_16way)
 		     %xmm8, %rsi);
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(camellia_ctr_16way)
 
 #define gf128mul_x_ble(iv, mask, tmp) \
@@ -1253,7 +1253,7 @@ SYM_FUNC_START_LOCAL(camellia_xts_crypt_16way)
 		     %xmm8, %rsi);
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(camellia_xts_crypt_16way)
 
 SYM_FUNC_START(camellia_xts_enc_16way)

arch/x86/crypto/camellia-aesni-avx2-asm_64.S

@@ -227,7 +227,7 @@ SYM_FUNC_START_LOCAL(roundsm32_x0_x1_x2_x3_x4_x5_x6_x7_y0_y1_y2_y3_y4_y5_y6_y7_c
 	roundsm32(%ymm0, %ymm1, %ymm2, %ymm3, %ymm4, %ymm5, %ymm6, %ymm7,
 		  %ymm8, %ymm9, %ymm10, %ymm11, %ymm12, %ymm13, %ymm14, %ymm15,
 		  %rcx, (%r9));
-	ret;
+	RET;
 SYM_FUNC_END(roundsm32_x0_x1_x2_x3_x4_x5_x6_x7_y0_y1_y2_y3_y4_y5_y6_y7_cd)
 
 .align 8
@@ -235,7 +235,7 @@ SYM_FUNC_START_LOCAL(roundsm32_x4_x5_x6_x7_x0_x1_x2_x3_y4_y5_y6_y7_y0_y1_y2_y3_a
 	roundsm32(%ymm4, %ymm5, %ymm6, %ymm7, %ymm0, %ymm1, %ymm2, %ymm3,
 		  %ymm12, %ymm13, %ymm14, %ymm15, %ymm8, %ymm9, %ymm10, %ymm11,
 		  %rax, (%r9));
-	ret;
+	RET;
 SYM_FUNC_END(roundsm32_x4_x5_x6_x7_x0_x1_x2_x3_y4_y5_y6_y7_y0_y1_y2_y3_ab)
 
 /*
@@ -825,7 +825,7 @@ SYM_FUNC_START_LOCAL(__camellia_enc_blk32)
 		    %ymm15, (key_table)(CTX, %r8, 8), (%rax), 1 * 32(%rax));
 
 	FRAME_END
-	ret;
+	RET;
 
 .align 8
 .Lenc_max32:
@@ -912,7 +912,7 @@ SYM_FUNC_START_LOCAL(__camellia_dec_blk32)
 		    %ymm15, (key_table)(CTX), (%rax), 1 * 32(%rax));
 
 	FRAME_END
-	ret;
+	RET;
 
 .align 8
 .Ldec_max32:
@@ -957,7 +957,7 @@ SYM_FUNC_START(camellia_ecb_enc_32way)
 	vzeroupper;
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(camellia_ecb_enc_32way)
 
 SYM_FUNC_START(camellia_ecb_dec_32way)
@@ -991,7 +991,7 @@ SYM_FUNC_START(camellia_ecb_dec_32way)
 	vzeroupper;
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(camellia_ecb_dec_32way)
 
 SYM_FUNC_START(camellia_cbc_dec_32way)
@@ -1059,7 +1059,7 @@ SYM_FUNC_START(camellia_cbc_dec_32way)
 	vzeroupper;
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(camellia_cbc_dec_32way)
 
 #define inc_le128(x, minus_one, tmp) \
@@ -1199,7 +1199,7 @@ SYM_FUNC_START(camellia_ctr_32way)
 	vzeroupper;
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(camellia_ctr_32way)
 
 #define gf128mul_x_ble(iv, mask, tmp) \
@@ -1366,7 +1366,7 @@ SYM_FUNC_START_LOCAL(camellia_xts_crypt_32way)
 	vzeroupper;
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(camellia_xts_crypt_32way)
 
 SYM_FUNC_START(camellia_xts_enc_32way)

arch/x86/crypto/camellia-x86_64-asm_64.S

@@ -213,13 +213,13 @@ SYM_FUNC_START(__camellia_enc_blk)
 	enc_outunpack(mov, RT1);
 
 	movq RR12, %r12;
-	ret;
+	RET;
 
 .L__enc_xor:
 	enc_outunpack(xor, RT1);
 
 	movq RR12, %r12;
-	ret;
+	RET;
 SYM_FUNC_END(__camellia_enc_blk)
 
 SYM_FUNC_START(camellia_dec_blk)
@@ -257,7 +257,7 @@ SYM_FUNC_START(camellia_dec_blk)
 	dec_outunpack();
 
 	movq RR12, %r12;
-	ret;
+	RET;
 SYM_FUNC_END(camellia_dec_blk)
 
 /**********************************************************************
@@ -448,14 +448,14 @@ SYM_FUNC_START(__camellia_enc_blk_2way)
 
 	movq RR12, %r12;
 	popq %rbx;
-	ret;
+	RET;
 
 .L__enc2_xor:
 	enc_outunpack2(xor, RT2);
 
 	movq RR12, %r12;
 	popq %rbx;
-	ret;
+	RET;
 SYM_FUNC_END(__camellia_enc_blk_2way)
 
 SYM_FUNC_START(camellia_dec_blk_2way)
@@ -495,5 +495,5 @@ SYM_FUNC_START(camellia_dec_blk_2way)
 
 	movq RR12, %r12;
 	movq RXOR, %rbx;
-	ret;
+	RET;
 SYM_FUNC_END(camellia_dec_blk_2way)

arch/x86/crypto/cast5-avx-x86_64-asm_64.S

@@ -279,7 +279,7 @@ SYM_FUNC_START_LOCAL(__cast5_enc_blk16)
 	outunpack_blocks(RR3, RL3, RTMP, RX, RKM);
 	outunpack_blocks(RR4, RL4, RTMP, RX, RKM);
 
-	ret;
+	RET;
 SYM_FUNC_END(__cast5_enc_blk16)
 
 .align 16
@@ -352,7 +352,7 @@ SYM_FUNC_START_LOCAL(__cast5_dec_blk16)
 	outunpack_blocks(RR3, RL3, RTMP, RX, RKM);
 	outunpack_blocks(RR4, RL4, RTMP, RX, RKM);
 
-	ret;
+	RET;
 
 .L__skip_dec:
 	vpsrldq $4, RKR, RKR;
@@ -393,7 +393,7 @@ SYM_FUNC_START(cast5_ecb_enc_16way)
 
 	popq %r15;
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(cast5_ecb_enc_16way)
 
 SYM_FUNC_START(cast5_ecb_dec_16way)
@@ -431,7 +431,7 @@ SYM_FUNC_START(cast5_ecb_dec_16way)
 
 	popq %r15;
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(cast5_ecb_dec_16way)
 
 SYM_FUNC_START(cast5_cbc_dec_16way)
@@ -483,7 +483,7 @@ SYM_FUNC_START(cast5_cbc_dec_16way)
 	popq %r15;
 	popq %r12;
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(cast5_cbc_dec_16way)
 
 SYM_FUNC_START(cast5_ctr_16way)
@@ -559,5 +559,5 @@ SYM_FUNC_START(cast5_ctr_16way)
 	popq %r15;
 	popq %r12;
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(cast5_ctr_16way)

arch/x86/crypto/cast6-avx-x86_64-asm_64.S

@@ -291,7 +291,7 @@ SYM_FUNC_START_LOCAL(__cast6_enc_blk8)
 	outunpack_blocks(RA1, RB1, RC1, RD1, RTMP, RX, RKRF, RKM);
 	outunpack_blocks(RA2, RB2, RC2, RD2, RTMP, RX, RKRF, RKM);
 
-	ret;
+	RET;
 SYM_FUNC_END(__cast6_enc_blk8)
 
 .align 8
@@ -338,7 +338,7 @@ SYM_FUNC_START_LOCAL(__cast6_dec_blk8)
 	outunpack_blocks(RA1, RB1, RC1, RD1, RTMP, RX, RKRF, RKM);
 	outunpack_blocks(RA2, RB2, RC2, RD2, RTMP, RX, RKRF, RKM);
 
-	ret;
+	RET;
 SYM_FUNC_END(__cast6_dec_blk8)
 
 SYM_FUNC_START(cast6_ecb_enc_8way)
@@ -361,7 +361,7 @@ SYM_FUNC_START(cast6_ecb_enc_8way)
 
 	popq %r15;
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(cast6_ecb_enc_8way)
 
 SYM_FUNC_START(cast6_ecb_dec_8way)
@@ -384,7 +384,7 @@ SYM_FUNC_START(cast6_ecb_dec_8way)
 
 	popq %r15;
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(cast6_ecb_dec_8way)
 
 SYM_FUNC_START(cast6_cbc_dec_8way)
@@ -410,7 +410,7 @@ SYM_FUNC_START(cast6_cbc_dec_8way)
 	popq %r15;
 	popq %r12;
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(cast6_cbc_dec_8way)
 
 SYM_FUNC_START(cast6_ctr_8way)
@@ -438,7 +438,7 @@ SYM_FUNC_START(cast6_ctr_8way)
 	popq %r15;
 	popq %r12;
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(cast6_ctr_8way)
 
 SYM_FUNC_START(cast6_xts_enc_8way)
@@ -465,7 +465,7 @@ SYM_FUNC_START(cast6_xts_enc_8way)
 
 	popq %r15;
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(cast6_xts_enc_8way)
 
 SYM_FUNC_START(cast6_xts_dec_8way)
@@ -492,5 +492,5 @@ SYM_FUNC_START(cast6_xts_dec_8way)
 
 	popq %r15;
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(cast6_xts_dec_8way)

arch/x86/crypto/chacha-avx2-x86_64.S

@@ -193,7 +193,7 @@ SYM_FUNC_START(chacha_2block_xor_avx2)
 
 .Ldone2:
 	vzeroupper
-	ret
+	RET
 
 .Lxorpart2:
 	# xor remaining bytes from partial register into output
@@ -498,7 +498,7 @@ SYM_FUNC_START(chacha_4block_xor_avx2)
 
 .Ldone4:
 	vzeroupper
-	ret
+	RET
 
 .Lxorpart4:
 	# xor remaining bytes from partial register into output
@@ -992,7 +992,7 @@ SYM_FUNC_START(chacha_8block_xor_avx2)
 .Ldone8:
 	vzeroupper
 	lea		-8(%r10),%rsp
-	ret
+	RET
 
 .Lxorpart8:
 	# xor remaining bytes from partial register into output

arch/x86/crypto/chacha-avx512vl-x86_64.S

@@ -166,7 +166,7 @@ SYM_FUNC_START(chacha_2block_xor_avx512vl)
 
 .Ldone2:
 	vzeroupper
-	ret
+	RET
 
 .Lxorpart2:
 	# xor remaining bytes from partial register into output
@@ -432,7 +432,7 @@ SYM_FUNC_START(chacha_4block_xor_avx512vl)
 
 .Ldone4:
 	vzeroupper
-	ret
+	RET
 
 .Lxorpart4:
 	# xor remaining bytes from partial register into output
@@ -812,7 +812,7 @@ SYM_FUNC_START(chacha_8block_xor_avx512vl)
 
 .Ldone8:
 	vzeroupper
-	ret
+	RET
 
 .Lxorpart8:
 	# xor remaining bytes from partial register into output

arch/x86/crypto/chacha-ssse3-x86_64.S

@@ -108,7 +108,7 @@ SYM_FUNC_START_LOCAL(chacha_permute)
 	sub		$2,%r8d
 	jnz		.Ldoubleround
 
-	ret
+	RET
 SYM_FUNC_END(chacha_permute)
 
 SYM_FUNC_START(chacha_block_xor_ssse3)
@@ -166,7 +166,7 @@ SYM_FUNC_START(chacha_block_xor_ssse3)
 
 .Ldone:
 	FRAME_END
-	ret
+	RET
 
 .Lxorpart:
 	# xor remaining bytes from partial register into output
@@ -217,7 +217,7 @@ SYM_FUNC_START(hchacha_block_ssse3)
 	movdqu		%xmm3,0x10(%rsi)
 
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(hchacha_block_ssse3)
 
 SYM_FUNC_START(chacha_4block_xor_ssse3)
@@ -762,7 +762,7 @@ SYM_FUNC_START(chacha_4block_xor_ssse3)
 
 .Ldone4:
 	lea		-8(%r10),%rsp
-	ret
+	RET
 
 .Lxorpart4:
 	# xor remaining bytes from partial register into output

arch/x86/crypto/crc32-pclmul_asm.S

@@ -236,5 +236,5 @@ fold_64:
 	pxor    %xmm2, %xmm1
 	pextrd  $0x01, %xmm1, %eax
 
-	ret
+	RET
 SYM_FUNC_END(crc32_pclmul_le_16)

arch/x86/crypto/crc32c-pcl-intel-asm_64.S

@@ -309,7 +309,7 @@ do_return:
 	popq    %rsi
 	popq    %rdi
 	popq    %rbx
-        ret
+        RET
 SYM_FUNC_END(crc_pcl)
 
 .section	.rodata, "a", @progbits

arch/x86/crypto/crct10dif-pcl-asm_64.S

@@ -257,7 +257,7 @@ SYM_FUNC_START(crc_t10dif_pcl)
 	# Final CRC value (x^16 * M(x)) mod G(x) is in low 16 bits of xmm0.
 
 	pextrw	$0, %xmm0, %eax
-	ret
+	RET
 
 .align 16
 .Lless_than_256_bytes:

arch/x86/crypto/des3_ede-asm_64.S

@@ -243,7 +243,7 @@ SYM_FUNC_START(des3_ede_x86_64_crypt_blk)
 	popq %r12;
 	popq %rbx;
 
-	ret;
+	RET;
 SYM_FUNC_END(des3_ede_x86_64_crypt_blk)
 
 /***********************************************************************
@@ -528,7 +528,7 @@ SYM_FUNC_START(des3_ede_x86_64_crypt_blk_3way)
 	popq %r12;
 	popq %rbx;
 
-	ret;
+	RET;
 SYM_FUNC_END(des3_ede_x86_64_crypt_blk_3way)
 
 .section	.rodata, "a", @progbits

arch/x86/crypto/ghash-clmulni-intel_asm.S

@@ -85,7 +85,7 @@ SYM_FUNC_START_LOCAL(__clmul_gf128mul_ble)
 	psrlq $1, T2
 	pxor T2, T1
 	pxor T1, DATA
-	ret
+	RET
 SYM_FUNC_END(__clmul_gf128mul_ble)
 
 /* void clmul_ghash_mul(char *dst, const u128 *shash) */
@@ -99,7 +99,7 @@ SYM_FUNC_START(clmul_ghash_mul)
 	pshufb BSWAP, DATA
 	movups DATA, (%rdi)
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(clmul_ghash_mul)
 
 /*
@@ -128,5 +128,5 @@ SYM_FUNC_START(clmul_ghash_update)
 	movups DATA, (%rdi)
 .Lupdate_just_ret:
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(clmul_ghash_update)

arch/x86/crypto/nh-avx2-x86_64.S

@@ -153,5 +153,5 @@ SYM_FUNC_START(nh_avx2)
 	vpaddq		T1, T0, T0
 	vpaddq		T4, T0, T0
 	vmovdqu		T0, (HASH)
-	ret
+	RET
 SYM_FUNC_END(nh_avx2)

arch/x86/crypto/nh-sse2-x86_64.S

@@ -119,5 +119,5 @@ SYM_FUNC_START(nh_sse2)
 	paddq		PASS2_SUMS, T1
 	movdqu		T0, 0x00(HASH)
 	movdqu		T1, 0x10(HASH)
-	ret
+	RET
 SYM_FUNC_END(nh_sse2)

arch/x86/crypto/poly1305-x86_64-cryptogams.pl

@@ -297,7 +297,7 @@ ___
 $code.=<<___;
 	mov	\$1,%eax
 .Lno_key:
-	ret
+	RET
 ___
 &end_function("poly1305_init_x86_64");
 
@@ -373,7 +373,7 @@ $code.=<<___;
 .cfi_adjust_cfa_offset	-48
 .Lno_data:
 .Lblocks_epilogue:
-	ret
+	RET
 .cfi_endproc
 ___
 &end_function("poly1305_blocks_x86_64");
@@ -399,7 +399,7 @@ $code.=<<___;
 	mov	%rax,0($mac)	# write result
 	mov	%rcx,8($mac)
 
-	ret
+	RET
 ___
 &end_function("poly1305_emit_x86_64");
 if ($avx) {
@@ -429,7 +429,7 @@ ___
 	&poly1305_iteration();
 $code.=<<___;
 	pop $ctx
-	ret
+	RET
 .size	__poly1305_block,.-__poly1305_block
 
 .type	__poly1305_init_avx,\@abi-omnipotent
@@ -594,7 +594,7 @@ __poly1305_init_avx:
 
 	lea	-48-64($ctx),$ctx	# size [de-]optimization
 	pop %rbp
-	ret
+	RET
 .size	__poly1305_init_avx,.-__poly1305_init_avx
 ___
 
@@ -747,7 +747,7 @@ $code.=<<___;
 .cfi_restore	%rbp
 .Lno_data_avx:
 .Lblocks_avx_epilogue:
-	ret
+	RET
 .cfi_endproc
 
 .align	32
@@ -1452,7 +1452,7 @@ $code.=<<___	if (!$win64);
 ___
 $code.=<<___;
 	vzeroupper
-	ret
+	RET
 .cfi_endproc
 ___
 &end_function("poly1305_blocks_avx");
@@ -1508,7 +1508,7 @@ $code.=<<___;
 	mov	%rax,0($mac)	# write result
 	mov	%rcx,8($mac)
 
-	ret
+	RET
 ___
 &end_function("poly1305_emit_avx");
 
@@ -1675,7 +1675,7 @@ $code.=<<___;
 .cfi_restore 	%rbp
 .Lno_data_avx2$suffix:
 .Lblocks_avx2_epilogue$suffix:
-	ret
+	RET
 .cfi_endproc
 
 .align	32
@@ -2201,7 +2201,7 @@ $code.=<<___	if (!$win64);
 ___
 $code.=<<___;
 	vzeroupper
-	ret
+	RET
 .cfi_endproc
 ___
 if($avx > 2 && $avx512) {
@@ -2792,7 +2792,7 @@ $code.=<<___	if (!$win64);
 .cfi_def_cfa_register	%rsp
 ___
 $code.=<<___;
-	ret
+	RET
 .cfi_endproc
 ___
 
@@ -2893,7 +2893,7 @@ $code.=<<___	if ($flavour =~ /elf32/);
 ___
 $code.=<<___;
 	mov	\$1,%eax
-	ret
+	RET
 .size	poly1305_init_base2_44,.-poly1305_init_base2_44
 ___
 {
@@ -3010,7 +3010,7 @@ poly1305_blocks_vpmadd52:
 	jnz		.Lblocks_vpmadd52_4x
 
 .Lno_data_vpmadd52:
-	ret
+	RET
 .size	poly1305_blocks_vpmadd52,.-poly1305_blocks_vpmadd52
 ___
 }
@@ -3451,7 +3451,7 @@ poly1305_blocks_vpmadd52_4x:
 	vzeroall
 
 .Lno_data_vpmadd52_4x:
-	ret
+	RET
 .size	poly1305_blocks_vpmadd52_4x,.-poly1305_blocks_vpmadd52_4x
 ___
 }
@@ -3824,7 +3824,7 @@ $code.=<<___;
 	vzeroall
 
 .Lno_data_vpmadd52_8x:
-	ret
+	RET
 .size	poly1305_blocks_vpmadd52_8x,.-poly1305_blocks_vpmadd52_8x
 ___
 }
@@ -3861,7 +3861,7 @@ poly1305_emit_base2_44:
 	mov	%rax,0($mac)	# write result
 	mov	%rcx,8($mac)
 
-	ret
+	RET
 .size	poly1305_emit_base2_44,.-poly1305_emit_base2_44
 ___
 }	}	}
@@ -3916,7 +3916,7 @@ xor128_encrypt_n_pad:
 
 .Ldone_enc:
 	mov	$otp,%rax
-	ret
+	RET
 .size	xor128_encrypt_n_pad,.-xor128_encrypt_n_pad
 
 .globl	xor128_decrypt_n_pad
@@ -3967,7 +3967,7 @@ xor128_decrypt_n_pad:
 
 .Ldone_dec:
 	mov	$otp,%rax
-	ret
+	RET
 .size	xor128_decrypt_n_pad,.-xor128_decrypt_n_pad
 ___
 }
@@ -4109,7 +4109,7 @@ avx_handler:
 	pop	%rbx
 	pop	%rdi
 	pop	%rsi
-	ret
+	RET
 .size	avx_handler,.-avx_handler
 
 .section	.pdata

arch/x86/crypto/serpent-avx-x86_64-asm_64.S

@@ -605,7 +605,7 @@ SYM_FUNC_START_LOCAL(__serpent_enc_blk8_avx)
 	write_blocks(RA1, RB1, RC1, RD1, RK0, RK1, RK2);
 	write_blocks(RA2, RB2, RC2, RD2, RK0, RK1, RK2);
 
-	ret;
+	RET;
 SYM_FUNC_END(__serpent_enc_blk8_avx)
 
 .align 8
@@ -659,7 +659,7 @@ SYM_FUNC_START_LOCAL(__serpent_dec_blk8_avx)
 	write_blocks(RC1, RD1, RB1, RE1, RK0, RK1, RK2);
 	write_blocks(RC2, RD2, RB2, RE2, RK0, RK1, RK2);
 
-	ret;
+	RET;
 SYM_FUNC_END(__serpent_dec_blk8_avx)
 
 SYM_FUNC_START(serpent_ecb_enc_8way_avx)
@@ -677,7 +677,7 @@ SYM_FUNC_START(serpent_ecb_enc_8way_avx)
 	store_8way(%rsi, RA1, RB1, RC1, RD1, RA2, RB2, RC2, RD2);
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(serpent_ecb_enc_8way_avx)
 
 SYM_FUNC_START(serpent_ecb_dec_8way_avx)
@@ -695,7 +695,7 @@ SYM_FUNC_START(serpent_ecb_dec_8way_avx)
 	store_8way(%rsi, RC1, RD1, RB1, RE1, RC2, RD2, RB2, RE2);
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(serpent_ecb_dec_8way_avx)
 
 SYM_FUNC_START(serpent_cbc_dec_8way_avx)
@@ -713,7 +713,7 @@ SYM_FUNC_START(serpent_cbc_dec_8way_avx)
 	store_cbc_8way(%rdx, %rsi, RC1, RD1, RB1, RE1, RC2, RD2, RB2, RE2);
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(serpent_cbc_dec_8way_avx)
 
 SYM_FUNC_START(serpent_ctr_8way_avx)
@@ -733,7 +733,7 @@ SYM_FUNC_START(serpent_ctr_8way_avx)
 	store_ctr_8way(%rdx, %rsi, RA1, RB1, RC1, RD1, RA2, RB2, RC2, RD2);
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(serpent_ctr_8way_avx)
 
 SYM_FUNC_START(serpent_xts_enc_8way_avx)
@@ -755,7 +755,7 @@ SYM_FUNC_START(serpent_xts_enc_8way_avx)
 	store_xts_8way(%rsi, RA1, RB1, RC1, RD1, RA2, RB2, RC2, RD2);
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(serpent_xts_enc_8way_avx)
 
 SYM_FUNC_START(serpent_xts_dec_8way_avx)
@@ -777,5 +777,5 @@ SYM_FUNC_START(serpent_xts_dec_8way_avx)
 	store_xts_8way(%rsi, RC1, RD1, RB1, RE1, RC2, RD2, RB2, RE2);
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(serpent_xts_dec_8way_avx)

arch/x86/crypto/serpent-avx2-asm_64.S

@@ -611,7 +611,7 @@ SYM_FUNC_START_LOCAL(__serpent_enc_blk16)
 	write_blocks(RA1, RB1, RC1, RD1, RK0, RK1, RK2);
 	write_blocks(RA2, RB2, RC2, RD2, RK0, RK1, RK2);
 
-	ret;
+	RET;
 SYM_FUNC_END(__serpent_enc_blk16)
 
 .align 8
@@ -665,7 +665,7 @@ SYM_FUNC_START_LOCAL(__serpent_dec_blk16)
 	write_blocks(RC1, RD1, RB1, RE1, RK0, RK1, RK2);
 	write_blocks(RC2, RD2, RB2, RE2, RK0, RK1, RK2);
 
-	ret;
+	RET;
 SYM_FUNC_END(__serpent_dec_blk16)
 
 SYM_FUNC_START(serpent_ecb_enc_16way)
@@ -687,7 +687,7 @@ SYM_FUNC_START(serpent_ecb_enc_16way)
 	vzeroupper;
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(serpent_ecb_enc_16way)
 
 SYM_FUNC_START(serpent_ecb_dec_16way)
@@ -709,7 +709,7 @@ SYM_FUNC_START(serpent_ecb_dec_16way)
 	vzeroupper;
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(serpent_ecb_dec_16way)
 
 SYM_FUNC_START(serpent_cbc_dec_16way)
@@ -732,7 +732,7 @@ SYM_FUNC_START(serpent_cbc_dec_16way)
 	vzeroupper;
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(serpent_cbc_dec_16way)
 
 SYM_FUNC_START(serpent_ctr_16way)
@@ -757,7 +757,7 @@ SYM_FUNC_START(serpent_ctr_16way)
 	vzeroupper;
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(serpent_ctr_16way)
 
 SYM_FUNC_START(serpent_xts_enc_16way)
@@ -783,7 +783,7 @@ SYM_FUNC_START(serpent_xts_enc_16way)
 	vzeroupper;
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(serpent_xts_enc_16way)
 
 SYM_FUNC_START(serpent_xts_dec_16way)
@@ -809,5 +809,5 @@ SYM_FUNC_START(serpent_xts_dec_16way)
 	vzeroupper;
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(serpent_xts_dec_16way)

arch/x86/crypto/serpent-sse2-i586-asm_32.S

@@ -553,12 +553,12 @@ SYM_FUNC_START(__serpent_enc_blk_4way)
 
 	write_blocks(%eax, RA, RB, RC, RD, RT0, RT1, RE);
 
-	ret;
+	RET;
 
 .L__enc_xor4:
 	xor_blocks(%eax, RA, RB, RC, RD, RT0, RT1, RE);
 
-	ret;
+	RET;
 SYM_FUNC_END(__serpent_enc_blk_4way)
 
 SYM_FUNC_START(serpent_dec_blk_4way)
@@ -612,5 +612,5 @@ SYM_FUNC_START(serpent_dec_blk_4way)
 	movl arg_dst(%esp), %eax;
 	write_blocks(%eax, RC, RD, RB, RE, RT0, RT1, RA);
 
-	ret;
+	RET;
 SYM_FUNC_END(serpent_dec_blk_4way)

arch/x86/crypto/serpent-sse2-x86_64-asm_64.S

@@ -675,13 +675,13 @@ SYM_FUNC_START(__serpent_enc_blk_8way)
 	write_blocks(%rsi, RA1, RB1, RC1, RD1, RK0, RK1, RK2);
 	write_blocks(%rax, RA2, RB2, RC2, RD2, RK0, RK1, RK2);
 
-	ret;
+	RET;
 
 .L__enc_xor8:
 	xor_blocks(%rsi, RA1, RB1, RC1, RD1, RK0, RK1, RK2);
 	xor_blocks(%rax, RA2, RB2, RC2, RD2, RK0, RK1, RK2);
 
-	ret;
+	RET;
 SYM_FUNC_END(__serpent_enc_blk_8way)
 
 SYM_FUNC_START(serpent_dec_blk_8way)
@@ -735,5 +735,5 @@ SYM_FUNC_START(serpent_dec_blk_8way)
 	write_blocks(%rsi, RC1, RD1, RB1, RE1, RK0, RK1, RK2);
 	write_blocks(%rax, RC2, RD2, RB2, RE2, RK0, RK1, RK2);
 
-	ret;
+	RET;
 SYM_FUNC_END(serpent_dec_blk_8way)

arch/x86/crypto/sha1_avx2_x86_64_asm.S

@@ -674,7 +674,7 @@ _loop3:
 	pop	%r12
 	pop	%rbx
 
-	ret
+	RET
 
 	SYM_FUNC_END(\name)
 .endm

arch/x86/crypto/sha1_ni_asm.S

@@ -290,7 +290,7 @@ SYM_FUNC_START(sha1_ni_transform)
 .Ldone_hash:
 	mov		RSPSAVE, %rsp
 
-	ret
+	RET
 SYM_FUNC_END(sha1_ni_transform)
 
 .section	.rodata.cst16.PSHUFFLE_BYTE_FLIP_MASK, "aM", @progbits, 16

arch/x86/crypto/sha1_ssse3_asm.S

@@ -99,7 +99,7 @@
 	pop	%rbp
 	pop	%r12
 	pop	%rbx
-	ret
+	RET
 
 	SYM_FUNC_END(\name)
 .endm

arch/x86/crypto/sha256-avx-asm.S

@@ -458,7 +458,7 @@ done_hash:
 	popq    %r13
 	popq	%r12
 	popq    %rbx
-	ret
+	RET
 SYM_FUNC_END(sha256_transform_avx)
 
 .section	.rodata.cst256.K256, "aM", @progbits, 256

arch/x86/crypto/sha256-avx2-asm.S

@@ -711,7 +711,7 @@ done_hash:
 	popq	%r13
 	popq	%r12
 	popq	%rbx
-	ret
+	RET
 SYM_FUNC_END(sha256_transform_rorx)
 
 .section	.rodata.cst512.K256, "aM", @progbits, 512

arch/x86/crypto/sha256-ssse3-asm.S

@@ -472,7 +472,7 @@ done_hash:
 	popq    %r12
 	popq    %rbx
 
-	ret
+	RET
 SYM_FUNC_END(sha256_transform_ssse3)
 
 .section	.rodata.cst256.K256, "aM", @progbits, 256

arch/x86/crypto/sha256_ni_asm.S

@@ -326,7 +326,7 @@ SYM_FUNC_START(sha256_ni_transform)
 
 .Ldone_hash:
 
-	ret
+	RET
 SYM_FUNC_END(sha256_ni_transform)
 
 .section	.rodata.cst256.K256, "aM", @progbits, 256

arch/x86/crypto/sha512-avx-asm.S

@@ -364,7 +364,7 @@ updateblock:
 	mov	frame_RSPSAVE(%rsp), %rsp
 
 nowork:
-	ret
+	RET
 SYM_FUNC_END(sha512_transform_avx)
 
 ########################################################################

arch/x86/crypto/sha512-avx2-asm.S

@@ -681,7 +681,7 @@ done_hash:
 
 	# Restore Stack Pointer
 	mov	frame_RSPSAVE(%rsp), %rsp
-	ret
+	RET
 SYM_FUNC_END(sha512_transform_rorx)
 
 ########################################################################

arch/x86/crypto/sha512-ssse3-asm.S

@@ -366,7 +366,7 @@ updateblock:
 	mov	frame_RSPSAVE(%rsp), %rsp
 
 nowork:
-	ret
+	RET
 SYM_FUNC_END(sha512_transform_ssse3)
 
 ########################################################################

arch/x86/crypto/twofish-avx-x86_64-asm_64.S

@@ -272,7 +272,7 @@ SYM_FUNC_START_LOCAL(__twofish_enc_blk8)
 	outunpack_blocks(RC1, RD1, RA1, RB1, RK1, RX0, RY0, RK2);
 	outunpack_blocks(RC2, RD2, RA2, RB2, RK1, RX0, RY0, RK2);
 
-	ret;
+	RET;
 SYM_FUNC_END(__twofish_enc_blk8)
 
 .align 8
@@ -312,7 +312,7 @@ SYM_FUNC_START_LOCAL(__twofish_dec_blk8)
 	outunpack_blocks(RA1, RB1, RC1, RD1, RK1, RX0, RY0, RK2);
 	outunpack_blocks(RA2, RB2, RC2, RD2, RK1, RX0, RY0, RK2);
 
-	ret;
+	RET;
 SYM_FUNC_END(__twofish_dec_blk8)
 
 SYM_FUNC_START(twofish_ecb_enc_8way)
@@ -332,7 +332,7 @@ SYM_FUNC_START(twofish_ecb_enc_8way)
 	store_8way(%r11, RC1, RD1, RA1, RB1, RC2, RD2, RA2, RB2);
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(twofish_ecb_enc_8way)
 
 SYM_FUNC_START(twofish_ecb_dec_8way)
@@ -352,7 +352,7 @@ SYM_FUNC_START(twofish_ecb_dec_8way)
 	store_8way(%r11, RA1, RB1, RC1, RD1, RA2, RB2, RC2, RD2);
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(twofish_ecb_dec_8way)
 
 SYM_FUNC_START(twofish_cbc_dec_8way)
@@ -377,7 +377,7 @@ SYM_FUNC_START(twofish_cbc_dec_8way)
 	popq %r12;
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(twofish_cbc_dec_8way)
 
 SYM_FUNC_START(twofish_ctr_8way)
@@ -404,7 +404,7 @@ SYM_FUNC_START(twofish_ctr_8way)
 	popq %r12;
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(twofish_ctr_8way)
 
 SYM_FUNC_START(twofish_xts_enc_8way)
@@ -428,7 +428,7 @@ SYM_FUNC_START(twofish_xts_enc_8way)
 	store_xts_8way(%r11, RC1, RD1, RA1, RB1, RC2, RD2, RA2, RB2);
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(twofish_xts_enc_8way)
 
 SYM_FUNC_START(twofish_xts_dec_8way)
@@ -452,5 +452,5 @@ SYM_FUNC_START(twofish_xts_dec_8way)
 	store_xts_8way(%r11, RA1, RB1, RC1, RD1, RA2, RB2, RC2, RD2);
 
 	FRAME_END
-	ret;
+	RET;
 SYM_FUNC_END(twofish_xts_dec_8way)

arch/x86/crypto/twofish-i586-asm_32.S

@@ -260,7 +260,7 @@ SYM_FUNC_START(twofish_enc_blk)
 	pop	%ebx
 	pop	%ebp
 	mov	$1,	%eax
-	ret
+	RET
 SYM_FUNC_END(twofish_enc_blk)
 
 SYM_FUNC_START(twofish_dec_blk)
@@ -317,5 +317,5 @@ SYM_FUNC_START(twofish_dec_blk)
 	pop	%ebx
 	pop	%ebp
 	mov	$1,	%eax
-	ret
+	RET
 SYM_FUNC_END(twofish_dec_blk)

arch/x86/crypto/twofish-x86_64-asm_64-3way.S

@@ -258,7 +258,7 @@ SYM_FUNC_START(__twofish_enc_blk_3way)
 	popq %rbx;
 	popq %r12;
 	popq %r13;
-	ret;
+	RET;
 
 .L__enc_xor3:
 	outunpack_enc3(xor);
@@ -266,7 +266,7 @@ SYM_FUNC_START(__twofish_enc_blk_3way)
 	popq %rbx;
 	popq %r12;
 	popq %r13;
-	ret;
+	RET;
 SYM_FUNC_END(__twofish_enc_blk_3way)
 
 SYM_FUNC_START(twofish_dec_blk_3way)
@@ -301,5 +301,5 @@ SYM_FUNC_START(twofish_dec_blk_3way)
 	popq %rbx;
 	popq %r12;
 	popq %r13;
-	ret;
+	RET;
 SYM_FUNC_END(twofish_dec_blk_3way)

arch/x86/crypto/twofish-x86_64-asm_64.S

@@ -252,7 +252,7 @@ SYM_FUNC_START(twofish_enc_blk)
 
 	popq	R1
 	movl	$1,%eax
-	ret
+	RET
 SYM_FUNC_END(twofish_enc_blk)
 
 SYM_FUNC_START(twofish_dec_blk)
@@ -304,5 +304,5 @@ SYM_FUNC_START(twofish_dec_blk)
 
 	popq	R1
 	movl	$1,%eax
-	ret
+	RET
 SYM_FUNC_END(twofish_dec_blk)

arch/x86/entry/Makefile

@@ -21,7 +21,7 @@ CFLAGS_syscall_64.o		+= $(call cc-option,-Wno-override-init,)
 CFLAGS_syscall_32.o		+= $(call cc-option,-Wno-override-init,)
 CFLAGS_syscall_x32.o		+= $(call cc-option,-Wno-override-init,)
 
-obj-y				:= entry_$(BITS).o thunk_$(BITS).o syscall_$(BITS).o
+obj-y				:= entry.o entry_$(BITS).o thunk_$(BITS).o syscall_$(BITS).o
 obj-y				+= common.o
 
 obj-y				+= vdso/

arch/x86/entry/calling.h

@@ -6,6 +6,8 @@
 #include <asm/percpu.h>
 #include <asm/asm-offsets.h>
 #include <asm/processor-flags.h>
+#include <asm/msr.h>
+#include <asm/nospec-branch.h>
 
 /*
 
@@ -146,27 +148,19 @@ For 32-bit we have the following conventions - kernel is built with
 
 .endm
 
-.macro POP_REGS pop_rdi=1 skip_r11rcx=0
+.macro POP_REGS pop_rdi=1
 	popq %r15
 	popq %r14
 	popq %r13
 	popq %r12
 	popq %rbp
 	popq %rbx
-	.if \skip_r11rcx
-	popq %rsi
-	.else
 	popq %r11
-	.endif
 	popq %r10
 	popq %r9
 	popq %r8
 	popq %rax
-	.if \skip_r11rcx
-	popq %rsi
-	.else
 	popq %rcx
-	.endif
 	popq %rdx
 	popq %rsi
 	.if \pop_rdi
@@ -316,6 +310,66 @@ For 32-bit we have the following conventions - kernel is built with
 
 #endif
 
+/*
+ * IBRS kernel mitigation for Spectre_v2.
+ *
+ * Assumes full context is established (PUSH_REGS, CR3 and GS) and it clobbers
+ * the regs it uses (AX, CX, DX). Must be called before the first RET
+ * instruction (NOTE! UNTRAIN_RET includes a RET instruction)
+ *
+ * The optional argument is used to save/restore the current value,
+ * which is used on the paranoid paths.
+ *
+ * Assumes x86_spec_ctrl_{base,current} to have SPEC_CTRL_IBRS set.
+ */
+.macro IBRS_ENTER save_reg
+#ifdef CONFIG_CPU_IBRS_ENTRY
+	ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_KERNEL_IBRS
+	movl	$MSR_IA32_SPEC_CTRL, %ecx
+
+.ifnb \save_reg
+	rdmsr
+	shl	$32, %rdx
+	or	%rdx, %rax
+	mov	%rax, \save_reg
+	test	$SPEC_CTRL_IBRS, %eax
+	jz	.Ldo_wrmsr_\@
+	lfence
+	jmp	.Lend_\@
+.Ldo_wrmsr_\@:
+.endif
+
+	movq	PER_CPU_VAR(x86_spec_ctrl_current), %rdx
+	movl	%edx, %eax
+	shr	$32, %rdx
+	wrmsr
+.Lend_\@:
+#endif
+.endm
+
+/*
+ * Similar to IBRS_ENTER, requires KERNEL GS,CR3 and clobbers (AX, CX, DX)
+ * regs. Must be called after the last RET.
+ */
+.macro IBRS_EXIT save_reg
+#ifdef CONFIG_CPU_IBRS_ENTRY
+	ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_KERNEL_IBRS
+	movl	$MSR_IA32_SPEC_CTRL, %ecx
+
+.ifnb \save_reg
+	mov	\save_reg, %rdx
+.else
+	movq	PER_CPU_VAR(x86_spec_ctrl_current), %rdx
+	andl	$(~SPEC_CTRL_IBRS), %edx
+.endif
+
+	movl	%edx, %eax
+	shr	$32, %rdx
+	wrmsr
+.Lend_\@:
+#endif
+.endm
+
 /*
  * Mitigate Spectre v1 for conditional swapgs code paths.
  *

arch/x86/entry/entry.S

@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Common place for both 32- and 64-bit entry routines.
+ */
+
+#include <linux/linkage.h>
+#include <asm/export.h>
+#include <asm/msr-index.h>
+
+.pushsection .noinstr.text, "ax"
+
+SYM_FUNC_START(entry_ibpb)
+	movl	$MSR_IA32_PRED_CMD, %ecx
+	movl	$PRED_CMD_IBPB, %eax
+	xorl	%edx, %edx
+	wrmsr
+	RET
+SYM_FUNC_END(entry_ibpb)
+/* For KVM */
+EXPORT_SYMBOL_GPL(entry_ibpb);
+
+.popsection

arch/x86/entry/entry_32.S

@@ -40,7 +40,7 @@
 #include <asm/processor-flags.h>
 #include <asm/irq_vectors.h>
 #include <asm/cpufeatures.h>
-#include <asm/alternative-asm.h>
+#include <asm/alternative.h>
 #include <asm/asm.h>
 #include <asm/smap.h>
 #include <asm/frame.h>
@@ -782,7 +782,6 @@ SYM_CODE_START(__switch_to_asm)
 	movl	%ebx, PER_CPU_VAR(stack_canary)+stack_canary_offset
 #endif
 
-#ifdef CONFIG_RETPOLINE
 	/*
 	 * When switching from a shallower to a deeper call stack
 	 * the RSB may either underflow or use entries populated
@@ -791,7 +790,6 @@ SYM_CODE_START(__switch_to_asm)
 	 * speculative execution to prevent attack.
 	 */
 	FILL_RETURN_BUFFER %ebx, RSB_CLEAR_LOOPS, X86_FEATURE_RSB_CTXSW
-#endif
 
 	/* Restore flags or the incoming task to restore AC state. */
 	popfl
@@ -821,7 +819,7 @@ SYM_FUNC_START(schedule_tail_wrapper)
 	popl	%eax
 
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(schedule_tail_wrapper)
 .popsection
 

arch/x86/entry/entry_64.S

@@ -93,7 +93,7 @@ SYM_CODE_END(native_usergs_sysret64)
  */
 
 SYM_CODE_START(entry_SYSCALL_64)
-	UNWIND_HINT_EMPTY
+	UNWIND_HINT_ENTRY
 
 	swapgs
 	/* tss.sp2 is scratch space. */
@@ -117,6 +117,11 @@ SYM_INNER_LABEL(entry_SYSCALL_64_after_hwframe, SYM_L_GLOBAL)
 	/* IRQs are off. */
 	movq	%rax, %rdi
 	movq	%rsp, %rsi
+
+	/* clobbers %rax, make sure it is after saving the syscall nr */
+	IBRS_ENTER
+	UNTRAIN_RET
+
 	call	do_syscall_64		/* returns with IRQs disabled */
 
 	/*
@@ -191,8 +196,8 @@ SYM_INNER_LABEL(entry_SYSCALL_64_after_hwframe, SYM_L_GLOBAL)
 	 * perf profiles. Nothing jumps here.
 	 */
 syscall_return_via_sysret:
-	/* rcx and r11 are already restored (see code above) */
+	IBRS_EXIT
-	POP_REGS pop_rdi=0 skip_r11rcx=1
+	POP_REGS pop_rdi=0
 
 	/*
 	 * Now all regs are restored except RSP and RDI.
@@ -244,7 +249,6 @@ SYM_FUNC_START(__switch_to_asm)
 	movq	%rbx, PER_CPU_VAR(fixed_percpu_data) + stack_canary_offset
 #endif
 
-#ifdef CONFIG_RETPOLINE
 	/*
 	 * When switching from a shallower to a deeper call stack
 	 * the RSB may either underflow or use entries populated
@@ -253,7 +257,6 @@ SYM_FUNC_START(__switch_to_asm)
 	 * speculative execution to prevent attack.
 	 */
 	FILL_RETURN_BUFFER %r12, RSB_CLEAR_LOOPS, X86_FEATURE_RSB_CTXSW
-#endif
 
 	/* restore callee-saved registers */
 	popq	%r15
@@ -569,6 +572,7 @@ __irqentry_text_end:
 
 SYM_CODE_START_LOCAL(common_interrupt_return)
 SYM_INNER_LABEL(swapgs_restore_regs_and_return_to_usermode, SYM_L_GLOBAL)
+	IBRS_EXIT
 #ifdef CONFIG_DEBUG_ENTRY
 	/* Assert that pt_regs indicates user mode. */
 	testb	$3, CS(%rsp)
@@ -676,6 +680,7 @@ native_irq_return_ldt:
 	pushq	%rdi				/* Stash user RDI */
 	swapgs					/* to kernel GS */
 	SWITCH_TO_KERNEL_CR3 scratch_reg=%rdi	/* to kernel CR3 */
+	UNTRAIN_RET
 
 	movq	PER_CPU_VAR(espfix_waddr), %rdi
 	movq	%rax, (0*8)(%rdi)		/* user RAX */
@@ -740,7 +745,7 @@ SYM_FUNC_START(asm_load_gs_index)
 2:	ALTERNATIVE "", "mfence", X86_BUG_SWAPGS_FENCE
 	swapgs
 	FRAME_END
-	ret
+	RET
 SYM_FUNC_END(asm_load_gs_index)
 EXPORT_SYMBOL(asm_load_gs_index)
 
@@ -799,7 +804,7 @@ SYM_INNER_LABEL(asm_call_irq_on_stack, SYM_L_GLOBAL)
 
 	/* Restore the previous stack pointer from RBP. */
 	leaveq
-	ret
+	RET
 SYM_FUNC_END(asm_call_on_stack)
 
 #ifdef CONFIG_XEN_PV
@@ -888,6 +893,9 @@ SYM_CODE_END(xen_failsafe_callback)
  *              1 -> no SWAPGS on exit
  *
  *     Y        GSBASE value at entry, must be restored in paranoid_exit
+ *
+ * R14 - old CR3
+ * R15 - old SPEC_CTRL
  */
 SYM_CODE_START_LOCAL(paranoid_entry)
 	UNWIND_HINT_FUNC
@@ -932,7 +940,7 @@ SYM_CODE_START_LOCAL(paranoid_entry)
 	 * is needed here.
 	 */
 	SAVE_AND_SET_GSBASE scratch_reg=%rax save_reg=%rbx
-	ret
+	jmp .Lparanoid_gsbase_done
 
 .Lparanoid_entry_checkgs:
 	/* EBX = 1 -> kernel GSBASE active, no restore required */
@@ -951,9 +959,17 @@ SYM_CODE_START_LOCAL(paranoid_entry)
 	xorl	%ebx, %ebx
 	swapgs
 .Lparanoid_kernel_gsbase:
-
 	FENCE_SWAPGS_KERNEL_ENTRY
-	ret
+.Lparanoid_gsbase_done:
+
+	/*
+	 * Once we have CR3 and %GS setup save and set SPEC_CTRL. Just like
+	 * CR3 above, keep the old value in a callee saved register.
+	 */
+	IBRS_ENTER save_reg=%r15
+	UNTRAIN_RET
+
+	RET
 SYM_CODE_END(paranoid_entry)
 
 /*
@@ -974,9 +990,19 @@ SYM_CODE_END(paranoid_entry)
  *              1 -> no SWAPGS on exit
  *
  *     Y        User space GSBASE, must be restored unconditionally
+ *
+ * R14 - old CR3
+ * R15 - old SPEC_CTRL
  */
 SYM_CODE_START_LOCAL(paranoid_exit)
 	UNWIND_HINT_REGS
+
+	/*
+	 * Must restore IBRS state before both CR3 and %GS since we need access
+	 * to the per-CPU x86_spec_ctrl_shadow variable.
+	 */
+	IBRS_EXIT save_reg=%r15
+
 	/*
 	 * The order of operations is important. RESTORE_CR3 requires
 	 * kernel GSBASE.
@@ -1023,8 +1049,11 @@ SYM_CODE_START_LOCAL(error_entry)
 	FENCE_SWAPGS_USER_ENTRY
 	/* We have user CR3.  Change to kernel CR3. */
 	SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
+	IBRS_ENTER
+	UNTRAIN_RET
 
 .Lerror_entry_from_usermode_after_swapgs:
+
 	/* Put us onto the real thread stack. */
 	popq	%r12				/* save return addr in %12 */
 	movq	%rsp, %rdi			/* arg0 = pt_regs pointer */
@@ -1032,7 +1061,7 @@ SYM_CODE_START_LOCAL(error_entry)
 	movq	%rax, %rsp			/* switch stack */
 	ENCODE_FRAME_POINTER
 	pushq	%r12
-	ret
+	RET
 
 	/*
 	 * There are two places in the kernel that can potentially fault with
@@ -1063,7 +1092,8 @@ SYM_CODE_START_LOCAL(error_entry)
 	 */
 .Lerror_entry_done_lfence:
 	FENCE_SWAPGS_KERNEL_ENTRY
-	ret
+	ANNOTATE_UNRET_END
+	RET
 
 .Lbstep_iret:
 	/* Fix truncated RIP */
@@ -1078,6 +1108,8 @@ SYM_CODE_START_LOCAL(error_entry)
 	SWAPGS
 	FENCE_SWAPGS_USER_ENTRY
 	SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
+	IBRS_ENTER
+	UNTRAIN_RET
 
 	/*
 	 * Pretend that the exception came from user mode: set up pt_regs
@@ -1182,6 +1214,9 @@ SYM_CODE_START(asm_exc_nmi)
 	PUSH_AND_CLEAR_REGS rdx=(%rdx)
 	ENCODE_FRAME_POINTER
 
+	IBRS_ENTER
+	UNTRAIN_RET
+
 	/*
 	 * At this point we no longer need to worry about stack damage
 	 * due to nesting -- we're on the normal thread stack and we're
@@ -1404,6 +1439,9 @@ end_repeat_nmi:
 	movq	$-1, %rsi
 	call	exc_nmi
 
+	/* Always restore stashed SPEC_CTRL value (see paranoid_entry) */
+	IBRS_EXIT save_reg=%r15
+
 	/* Always restore stashed CR3 value (see paranoid_entry) */
 	RESTORE_CR3 scratch_reg=%r15 save_reg=%r14
 

arch/x86/entry/entry_64_compat.S

@@ -4,7 +4,6 @@
  *
  * Copyright 2000-2002 Andi Kleen, SuSE Labs.
  */
-#include "calling.h"
 #include <asm/asm-offsets.h>
 #include <asm/current.h>
 #include <asm/errno.h>
@@ -14,9 +13,12 @@
 #include <asm/irqflags.h>
 #include <asm/asm.h>
 #include <asm/smap.h>
+#include <asm/nospec-branch.h>
 #include <linux/linkage.h>
 #include <linux/err.h>
 
+#include "calling.h"
+
 	.section .entry.text, "ax"
 
 /*
@@ -47,7 +49,7 @@
  * 0(%ebp) arg6
  */
 SYM_CODE_START(entry_SYSENTER_compat)
-	UNWIND_HINT_EMPTY
+	UNWIND_HINT_ENTRY
 	/* Interrupts are off on entry. */
 	SWAPGS
 
@@ -112,6 +114,9 @@ SYM_INNER_LABEL(entry_SYSENTER_compat_after_hwframe, SYM_L_GLOBAL)
 
 	cld
 
+	IBRS_ENTER
+	UNTRAIN_RET
+
 	/*
 	 * SYSENTER doesn't filter flags, so we need to clear NT and AC
 	 * ourselves.  To save a few cycles, we can check whether
@@ -197,7 +202,7 @@ SYM_CODE_END(entry_SYSENTER_compat)
  * 0(%esp) arg6
  */
 SYM_CODE_START(entry_SYSCALL_compat)
-	UNWIND_HINT_EMPTY
+	UNWIND_HINT_ENTRY
 	/* Interrupts are off on entry. */
 	swapgs
 
@@ -252,6 +257,9 @@ SYM_INNER_LABEL(entry_SYSCALL_compat_after_hwframe, SYM_L_GLOBAL)
 
 	UNWIND_HINT_REGS
 
+	IBRS_ENTER
+	UNTRAIN_RET
+
 	movq	%rsp, %rdi
 	call	do_fast_syscall_32
 	/* XEN PV guests always use IRET path */
@@ -266,6 +274,8 @@ sysret32_from_system_call:
 	 */
 	STACKLEAK_ERASE
 
+	IBRS_EXIT
+
 	movq	RBX(%rsp), %rbx		/* pt_regs->rbx */
 	movq	RBP(%rsp), %rbp		/* pt_regs->rbp */
 	movq	EFLAGS(%rsp), %r11	/* pt_regs->flags (in r11) */
@@ -339,7 +349,7 @@ SYM_CODE_END(entry_SYSCALL_compat)
  * ebp  arg6
  */
 SYM_CODE_START(entry_INT80_compat)
-	UNWIND_HINT_EMPTY
+	UNWIND_HINT_ENTRY
 	/*
 	 * Interrupts are off on entry.
 	 */
@@ -409,6 +419,9 @@ SYM_CODE_START(entry_INT80_compat)
 
 	cld
 
+	IBRS_ENTER
+	UNTRAIN_RET
+
 	movq	%rsp, %rdi
 	call	do_int80_syscall_32
 	jmp	swapgs_restore_regs_and_return_to_usermode

arch/x86/entry/thunk_32.S

@@ -24,7 +24,7 @@ SYM_CODE_START_NOALIGN(\name)
 	popl %edx
 	popl %ecx
 	popl %eax
-	ret
+	RET
 	_ASM_NOKPROBE(\name)
 SYM_CODE_END(\name)
 	.endm

arch/x86/entry/thunk_64.S

@@ -55,7 +55,7 @@ SYM_CODE_START_LOCAL_NOALIGN(__thunk_restore)
 	popq %rsi
 	popq %rdi
 	popq %rbp
-	ret
+	RET
 	_ASM_NOKPROBE(__thunk_restore)
 SYM_CODE_END(__thunk_restore)
 #endif

arch/x86/entry/vdso/Makefile

@@ -91,6 +91,7 @@ endif
 endif
 
 $(vobjs): KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO) $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
+$(vobjs): KBUILD_AFLAGS += -DBUILD_VDSO
 
 #
 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.

arch/x86/entry/vdso/vdso32/system_call.S

@@ -6,7 +6,7 @@
 #include <linux/linkage.h>
 #include <asm/dwarf2.h>
 #include <asm/cpufeatures.h>
-#include <asm/alternative-asm.h>
+#include <asm/alternative.h>
 
 	.text
 	.globl __kernel_vsyscall
@@ -78,7 +78,7 @@ SYM_INNER_LABEL(int80_landing_pad, SYM_L_GLOBAL)
 	popl	%ecx
 	CFI_RESTORE		ecx
 	CFI_ADJUST_CFA_OFFSET	-4
-	ret
+	RET
 	CFI_ENDPROC
 
 	.size __kernel_vsyscall,.-__kernel_vsyscall

arch/x86/entry/vsyscall/vsyscall_emu_64.S

@@ -20,16 +20,19 @@ __vsyscall_page:
 	mov $__NR_gettimeofday, %rax
 	syscall
 	ret
+	int3
 
 	.balign 1024, 0xcc
 	mov $__NR_time, %rax
 	syscall
 	ret
+	int3
 
 	.balign 1024, 0xcc
 	mov $__NR_getcpu, %rax
 	syscall
 	ret
+	int3
 
 	.balign 4096, 0xcc
 

arch/x86/include/asm/GEN-for-each-reg.h

@@ -1,11 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * These are in machine order; things rely on that.
+ */
 #ifdef CONFIG_64BIT
 GEN(rax)
-GEN(rbx)
 GEN(rcx)
 GEN(rdx)
+GEN(rbx)
+GEN(rsp)
+GEN(rbp)
 GEN(rsi)
 GEN(rdi)
-GEN(rbp)
 GEN(r8)
 GEN(r9)
 GEN(r10)
@@ -16,10 +21,11 @@ GEN(r14)
 GEN(r15)
 #else
 GEN(eax)
-GEN(ebx)
 GEN(ecx)
 GEN(edx)
+GEN(ebx)
+GEN(esp)
+GEN(ebp)
 GEN(esi)
 GEN(edi)
-GEN(ebp)
 #endif

arch/x86/include/asm/alternative-asm.h

@@ -1,114 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_X86_ALTERNATIVE_ASM_H
-#define _ASM_X86_ALTERNATIVE_ASM_H
-
-#ifdef __ASSEMBLY__
-
-#include <asm/asm.h>
-
-#ifdef CONFIG_SMP
-	.macro LOCK_PREFIX
-672:	lock
-	.pushsection .smp_locks,"a"
-	.balign 4
-	.long 672b - .
-	.popsection
-	.endm
-#else
-	.macro LOCK_PREFIX
-	.endm
-#endif
-
-/*
- * objtool annotation to ignore the alternatives and only consider the original
- * instruction(s).
- */
-.macro ANNOTATE_IGNORE_ALTERNATIVE
-	.Lannotate_\@:
-	.pushsection .discard.ignore_alts
-	.long .Lannotate_\@ - .
-	.popsection
-.endm
-
-/*
- * Issue one struct alt_instr descriptor entry (need to put it into
- * the section .altinstructions, see below). This entry contains
- * enough information for the alternatives patching code to patch an
- * instruction. See apply_alternatives().
- */
-.macro altinstruction_entry orig alt feature orig_len alt_len pad_len
-	.long \orig - .
-	.long \alt - .
-	.word \feature
-	.byte \orig_len
-	.byte \alt_len
-	.byte \pad_len
-.endm
-
-/*
- * Define an alternative between two instructions. If @feature is
- * present, early code in apply_alternatives() replaces @oldinstr with
- * @newinstr. ".skip" directive takes care of proper instruction padding
- * in case @newinstr is longer than @oldinstr.
- */
-.macro ALTERNATIVE oldinstr, newinstr, feature
-140:
-	\oldinstr
-141:
-	.skip -(((144f-143f)-(141b-140b)) > 0) * ((144f-143f)-(141b-140b)),0x90
-142:
-
-	.pushsection .altinstructions,"a"
-	altinstruction_entry 140b,143f,\feature,142b-140b,144f-143f,142b-141b
-	.popsection
-
-	.pushsection .altinstr_replacement,"ax"
-143:
-	\newinstr
-144:
-	.popsection
-.endm
-
-#define old_len			141b-140b
-#define new_len1		144f-143f
-#define new_len2		145f-144f
-
-/*
- * gas compatible max based on the idea from:
- * http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax
- *
- * The additional "-" is needed because gas uses a "true" value of -1.
- */
-#define alt_max_short(a, b)	((a) ^ (((a) ^ (b)) & -(-((a) < (b)))))
-
-
-/*
- * Same as ALTERNATIVE macro above but for two alternatives. If CPU
- * has @feature1, it replaces @oldinstr with @newinstr1. If CPU has
- * @feature2, it replaces @oldinstr with @feature2.
- */
-.macro ALTERNATIVE_2 oldinstr, newinstr1, feature1, newinstr2, feature2
-140:
-	\oldinstr
-141:
-	.skip -((alt_max_short(new_len1, new_len2) - (old_len)) > 0) * \
-		(alt_max_short(new_len1, new_len2) - (old_len)),0x90
-142:
-
-	.pushsection .altinstructions,"a"
-	altinstruction_entry 140b,143f,\feature1,142b-140b,144f-143f,142b-141b
-	altinstruction_entry 140b,144f,\feature2,142b-140b,145f-144f,142b-141b
-	.popsection
-
-	.pushsection .altinstr_replacement,"ax"
-143:
-	\newinstr1
-144:
-	\newinstr2
-145:
-	.popsection
-.endm
-
-#endif  /*  __ASSEMBLY__  */
-
-#endif /* _ASM_X86_ALTERNATIVE_ASM_H */

arch/x86/include/asm/alternative.h

@@ -2,13 +2,17 @@
 #ifndef _ASM_X86_ALTERNATIVE_H
 #define _ASM_X86_ALTERNATIVE_H
 
-#ifndef __ASSEMBLY__
-
 #include <linux/types.h>
-#include <linux/stddef.h>
 #include <linux/stringify.h>
 #include <asm/asm.h>
 
+#define ALTINSTR_FLAG_INV	(1 << 15)
+#define ALT_NOT(feat)		((feat) | ALTINSTR_FLAG_INV)
+
+#ifndef __ASSEMBLY__
+
+#include <linux/stddef.h>
+
 /*
  * Alternative inline assembly for SMP.
  *
@@ -61,7 +65,6 @@ struct alt_instr {
 	u16 cpuid;		/* cpuid bit set for replacement */
 	u8  instrlen;		/* length of original instruction */
 	u8  replacementlen;	/* length of new instruction */
-	u8  padlen;		/* length of build-time padding */
 } __packed;
 
 /*
@@ -72,6 +75,8 @@ extern int alternatives_patched;
 
 extern void alternative_instructions(void);
 extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
+extern void apply_retpolines(s32 *start, s32 *end);
+extern void apply_returns(s32 *start, s32 *end);
 
 struct module;
 
@@ -100,7 +105,6 @@ static inline int alternatives_text_reserved(void *start, void *end)
 
 #define alt_end_marker		"663"
 #define alt_slen		"662b-661b"
-#define alt_pad_len		alt_end_marker"b-662b"
 #define alt_total_slen		alt_end_marker"b-661b"
 #define alt_rlen(num)		e_replacement(num)"f-"b_replacement(num)"f"
 
@@ -147,8 +151,7 @@ static inline int alternatives_text_reserved(void *start, void *end)
 	" .long " b_replacement(num)"f - .\n"		/* new instruction */ \
 	" .word " __stringify(feature) "\n"		/* feature bit     */ \
 	" .byte " alt_total_slen "\n"			/* source len      */ \
-	" .byte " alt_rlen(num) "\n"			/* replacement len */ \
+	" .byte " alt_rlen(num) "\n"			/* replacement len */
-	" .byte " alt_pad_len "\n"			/* pad len */
 
 #define ALTINSTR_REPLACEMENT(newinstr, feature, num)	/* replacement */	\
 	"# ALT: replacement " #num "\n"						\
@@ -175,6 +178,11 @@ static inline int alternatives_text_reserved(void *start, void *end)
 	ALTINSTR_REPLACEMENT(newinstr2, feature2, 2)			\
 	".popsection\n"
 
+/* If @feature is set, patch in @newinstr_yes, otherwise @newinstr_no. */
+#define ALTERNATIVE_TERNARY(oldinstr, feature, newinstr_yes, newinstr_no) \
+	ALTERNATIVE_2(oldinstr, newinstr_no, X86_FEATURE_ALWAYS,	\
+		      newinstr_yes, feature)
+
 #define ALTERNATIVE_3(oldinsn, newinsn1, feat1, newinsn2, feat2, newinsn3, feat3) \
 	OLDINSTR_3(oldinsn, 1, 2, 3)						\
 	".pushsection .altinstructions,\"a\"\n"					\
@@ -206,15 +214,15 @@ static inline int alternatives_text_reserved(void *start, void *end)
 #define alternative_2(oldinstr, newinstr1, feature1, newinstr2, feature2) \
 	asm_inline volatile(ALTERNATIVE_2(oldinstr, newinstr1, feature1, newinstr2, feature2) ::: "memory")
 
+#define alternative_ternary(oldinstr, feature, newinstr_yes, newinstr_no) \
+	asm_inline volatile(ALTERNATIVE_TERNARY(oldinstr, feature, newinstr_yes, newinstr_no) ::: "memory")
+
 /*
  * Alternative inline assembly with input.
  *
  * Peculiarities:
  * No memory clobber here.
  * Argument numbers start with 1.
- * Best is to use constraints that are fixed size (like (%1) ... "r")
- * If you use variable sized constraints like "m" or "g" in the
- * replacement make sure to pad to the worst case length.
  * Leaving an unused argument 0 to keep API compatibility.
  */
 #define alternative_input(oldinstr, newinstr, feature, input...)	\
@@ -271,6 +279,115 @@ static inline int alternatives_text_reserved(void *start, void *end)
  */
 #define ASM_NO_INPUT_CLOBBER(clbr...) "i" (0) : clbr
 
+#else /* __ASSEMBLY__ */
+
+#ifdef CONFIG_SMP
+	.macro LOCK_PREFIX
+672:	lock
+	.pushsection .smp_locks,"a"
+	.balign 4
+	.long 672b - .
+	.popsection
+	.endm
+#else
+	.macro LOCK_PREFIX
+	.endm
+#endif
+
+/*
+ * objtool annotation to ignore the alternatives and only consider the original
+ * instruction(s).
+ */
+.macro ANNOTATE_IGNORE_ALTERNATIVE
+	.Lannotate_\@:
+	.pushsection .discard.ignore_alts
+	.long .Lannotate_\@ - .
+	.popsection
+.endm
+
+/*
+ * Issue one struct alt_instr descriptor entry (need to put it into
+ * the section .altinstructions, see below). This entry contains
+ * enough information for the alternatives patching code to patch an
+ * instruction. See apply_alternatives().
+ */
+.macro altinstruction_entry orig alt feature orig_len alt_len
+	.long \orig - .
+	.long \alt - .
+	.word \feature
+	.byte \orig_len
+	.byte \alt_len
+.endm
+
+/*
+ * Define an alternative between two instructions. If @feature is
+ * present, early code in apply_alternatives() replaces @oldinstr with
+ * @newinstr. ".skip" directive takes care of proper instruction padding
+ * in case @newinstr is longer than @oldinstr.
+ */
+.macro ALTERNATIVE oldinstr, newinstr, feature
+140:
+	\oldinstr
+141:
+	.skip -(((144f-143f)-(141b-140b)) > 0) * ((144f-143f)-(141b-140b)),0x90
+142:
+
+	.pushsection .altinstructions,"a"
+	altinstruction_entry 140b,143f,\feature,142b-140b,144f-143f
+	.popsection
+
+	.pushsection .altinstr_replacement,"ax"
+143:
+	\newinstr
+144:
+	.popsection
+.endm
+
+#define old_len			141b-140b
+#define new_len1		144f-143f
+#define new_len2		145f-144f
+
+/*
+ * gas compatible max based on the idea from:
+ * http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax
+ *
+ * The additional "-" is needed because gas uses a "true" value of -1.
+ */
+#define alt_max_short(a, b)	((a) ^ (((a) ^ (b)) & -(-((a) < (b)))))
+
+
+/*
+ * Same as ALTERNATIVE macro above but for two alternatives. If CPU
+ * has @feature1, it replaces @oldinstr with @newinstr1. If CPU has
+ * @feature2, it replaces @oldinstr with @feature2.
+ */
+.macro ALTERNATIVE_2 oldinstr, newinstr1, feature1, newinstr2, feature2
+140:
+	\oldinstr
+141:
+	.skip -((alt_max_short(new_len1, new_len2) - (old_len)) > 0) * \
+		(alt_max_short(new_len1, new_len2) - (old_len)),0x90
+142:
+
+	.pushsection .altinstructions,"a"
+	altinstruction_entry 140b,143f,\feature1,142b-140b,144f-143f
+	altinstruction_entry 140b,144f,\feature2,142b-140b,145f-144f
+	.popsection
+
+	.pushsection .altinstr_replacement,"ax"
+143:
+	\newinstr1
+144:
+	\newinstr2
+145:
+	.popsection
+.endm
+
+/* If @feature is set, patch in @newinstr_yes, otherwise @newinstr_no. */
+#define ALTERNATIVE_TERNARY(oldinstr, feature, newinstr_yes, newinstr_no) \
+	ALTERNATIVE_2 oldinstr, newinstr_no, X86_FEATURE_ALWAYS,	\
+	newinstr_yes, feature
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_X86_ALTERNATIVE_H */

arch/x86/include/asm/asm-prototypes.h

@@ -17,20 +17,3 @@
 extern void cmpxchg8b_emu(void);
 #endif
 
-#ifdef CONFIG_RETPOLINE
-
-#define DECL_INDIRECT_THUNK(reg) \
-	extern asmlinkage void __x86_indirect_thunk_ ## reg (void);
-
-#define DECL_RETPOLINE(reg) \
-	extern asmlinkage void __x86_retpoline_ ## reg (void);
-
-#undef GEN
-#define GEN(reg) DECL_INDIRECT_THUNK(reg)
-#include <asm/GEN-for-each-reg.h>
-
-#undef GEN
-#define GEN(reg) DECL_RETPOLINE(reg)
-#include <asm/GEN-for-each-reg.h>
-
-#endif /* CONFIG_RETPOLINE */

arch/x86/include/asm/cpufeature.h

@@ -8,6 +8,7 @@
 
 #include <asm/asm.h>
 #include <linux/bitops.h>
+#include <asm/alternative.h>
 
 enum cpuid_leafs
 {
@@ -172,39 +173,15 @@ extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
  */
 static __always_inline bool _static_cpu_has(u16 bit)
 {
-	asm_volatile_goto("1: jmp 6f\n"
+	asm_volatile_goto(
-		 "2:\n"
+		ALTERNATIVE_TERNARY("jmp 6f", %P[feature], "", "jmp %l[t_no]")
-		 ".skip -(((5f-4f) - (2b-1b)) > 0) * "
+		".section .altinstr_aux,\"ax\"\n"
-			 "((5f-4f) - (2b-1b)),0x90\n"
+		"6:\n"
-		 "3:\n"
+		" testb %[bitnum],%[cap_byte]\n"
-		 ".section .altinstructions,\"a\"\n"
+		" jnz %l[t_yes]\n"
-		 " .long 1b - .\n"		/* src offset */
+		" jmp %l[t_no]\n"
-		 " .long 4f - .\n"		/* repl offset */
+		".previous\n"
-		 " .word %P[always]\n"		/* always replace */
-		 " .byte 3b - 1b\n"		/* src len */
-		 " .byte 5f - 4f\n"		/* repl len */
-		 " .byte 3b - 2b\n"		/* pad len */
-		 ".previous\n"
-		 ".section .altinstr_replacement,\"ax\"\n"
-		 "4: jmp %l[t_no]\n"
-		 "5:\n"
-		 ".previous\n"
-		 ".section .altinstructions,\"a\"\n"
-		 " .long 1b - .\n"		/* src offset */
-		 " .long 0\n"			/* no replacement */
-		 " .word %P[feature]\n"		/* feature bit */
-		 " .byte 3b - 1b\n"		/* src len */
-		 " .byte 0\n"			/* repl len */
-		 " .byte 0\n"			/* pad len */
-		 ".previous\n"
-		 ".section .altinstr_aux,\"ax\"\n"
-		 "6:\n"
-		 " testb %[bitnum],%[cap_byte]\n"
-		 " jnz %l[t_yes]\n"
-		 " jmp %l[t_no]\n"
-		 ".previous\n"
 		 : : [feature]  "i" (bit),
-		     [always]   "i" (X86_FEATURE_ALWAYS),
 		     [bitnum]   "i" (1 << (bit & 7)),
 		     [cap_byte] "m" (((const char *)boot_cpu_data.x86_capability)[bit >> 3])
 		 : : t_yes, t_no);

arch/x86/include/asm/cpufeatures.h

@@ -203,8 +203,8 @@
 #define X86_FEATURE_PROC_FEEDBACK	( 7*32+ 9) /* AMD ProcFeedbackInterface */
 #define X86_FEATURE_SME			( 7*32+10) /* AMD Secure Memory Encryption */
 #define X86_FEATURE_PTI			( 7*32+11) /* Kernel Page Table Isolation enabled */
-#define X86_FEATURE_RETPOLINE		( 7*32+12) /* "" Generic Retpoline mitigation for Spectre variant 2 */
+#define X86_FEATURE_KERNEL_IBRS		( 7*32+12) /* "" Set/clear IBRS on kernel entry/exit */
-#define X86_FEATURE_RETPOLINE_LFENCE	( 7*32+13) /* "" Use LFENCE for Spectre variant 2 */
+#define X86_FEATURE_RSB_VMEXIT		( 7*32+13) /* "" Fill RSB on VM-Exit */
 #define X86_FEATURE_INTEL_PPIN		( 7*32+14) /* Intel Processor Inventory Number */
 #define X86_FEATURE_CDP_L2		( 7*32+15) /* Code and Data Prioritization L2 */
 #define X86_FEATURE_MSR_SPEC_CTRL	( 7*32+16) /* "" MSR SPEC_CTRL is implemented */
@@ -290,6 +290,14 @@
 #define X86_FEATURE_FENCE_SWAPGS_KERNEL	(11*32+ 5) /* "" LFENCE in kernel entry SWAPGS path */
 #define X86_FEATURE_SPLIT_LOCK_DETECT	(11*32+ 6) /* #AC for split lock */
 #define X86_FEATURE_PER_THREAD_MBA	(11*32+ 7) /* "" Per-thread Memory Bandwidth Allocation */
+/* FREE!				(11*32+ 8) */
+/* FREE!				(11*32+ 9) */
+#define X86_FEATURE_ENTRY_IBPB		(11*32+10) /* "" Issue an IBPB on kernel entry */
+#define X86_FEATURE_RRSBA_CTRL		(11*32+11) /* "" RET prediction control */
+#define X86_FEATURE_RETPOLINE		(11*32+12) /* "" Generic Retpoline mitigation for Spectre variant 2 */
+#define X86_FEATURE_RETPOLINE_LFENCE	(11*32+13) /* "" Use LFENCE for Spectre variant 2 */
+#define X86_FEATURE_RETHUNK		(11*32+14) /* "" Use REturn THUNK */
+#define X86_FEATURE_UNRET		(11*32+15) /* "" AMD BTB untrain return */
 
 /* Intel-defined CPU features, CPUID level 0x00000007:1 (EAX), word 12 */
 #define X86_FEATURE_AVX512_BF16		(12*32+ 5) /* AVX512 BFLOAT16 instructions */
@@ -308,6 +316,7 @@
 #define X86_FEATURE_AMD_SSBD		(13*32+24) /* "" Speculative Store Bypass Disable */
 #define X86_FEATURE_VIRT_SSBD		(13*32+25) /* Virtualized Speculative Store Bypass Disable */
 #define X86_FEATURE_AMD_SSB_NO		(13*32+26) /* "" Speculative Store Bypass is fixed in hardware. */
+#define X86_FEATURE_BTC_NO		(13*32+29) /* "" Not vulnerable to Branch Type Confusion */
 
 /* Thermal and Power Management Leaf, CPUID level 0x00000006 (EAX), word 14 */
 #define X86_FEATURE_DTHERM		(14*32+ 0) /* Digital Thermal Sensor */
@@ -418,5 +427,6 @@
 #define X86_BUG_ITLB_MULTIHIT		X86_BUG(23) /* CPU may incur MCE during certain page attribute changes */
 #define X86_BUG_SRBDS			X86_BUG(24) /* CPU may leak RNG bits if not mitigated */
 #define X86_BUG_MMIO_STALE_DATA		X86_BUG(25) /* CPU is affected by Processor MMIO Stale Data vulnerabilities */
+#define X86_BUG_RETBLEED		X86_BUG(26) /* CPU is affected by RETBleed */
 
 #endif /* _ASM_X86_CPUFEATURES_H */

arch/x86/include/asm/disabled-features.h

@@ -56,6 +56,25 @@
 # define DISABLE_PTI		(1 << (X86_FEATURE_PTI & 31))
 #endif
 
+#ifdef CONFIG_RETPOLINE
+# define DISABLE_RETPOLINE	0
+#else
+# define DISABLE_RETPOLINE	((1 << (X86_FEATURE_RETPOLINE & 31)) | \
+				 (1 << (X86_FEATURE_RETPOLINE_LFENCE & 31)))
+#endif
+
+#ifdef CONFIG_RETHUNK
+# define DISABLE_RETHUNK	0
+#else
+# define DISABLE_RETHUNK	(1 << (X86_FEATURE_RETHUNK & 31))
+#endif
+
+#ifdef CONFIG_CPU_UNRET_ENTRY
+# define DISABLE_UNRET		0
+#else
+# define DISABLE_UNRET		(1 << (X86_FEATURE_UNRET & 31))
+#endif
+
 /* Force disable because it's broken beyond repair */
 #define DISABLE_ENQCMD		(1 << (X86_FEATURE_ENQCMD & 31))
 
@@ -73,7 +92,7 @@
 #define DISABLED_MASK8	0
 #define DISABLED_MASK9	(DISABLE_SMAP)
 #define DISABLED_MASK10	0
-#define DISABLED_MASK11	0
+#define DISABLED_MASK11	(DISABLE_RETPOLINE|DISABLE_RETHUNK|DISABLE_UNRET)
 #define DISABLED_MASK12	0
 #define DISABLED_MASK13	0
 #define DISABLED_MASK14	0

arch/x86/include/asm/inat.h

@@ -6,7 +6,7 @@
  *
  * Written by Masami Hiramatsu <mhiramat@redhat.com>
  */
-#include <asm/inat_types.h>
+#include <asm/inat_types.h> /* __ignore_sync_check__ */
 
 /*
  * Internal bits. Don't use bitmasks directly, because these bits are

arch/x86/include/asm/insn-eval.h

@@ -26,7 +26,7 @@ int insn_fetch_from_user(struct pt_regs *regs,
 			 unsigned char buf[MAX_INSN_SIZE]);
 int insn_fetch_from_user_inatomic(struct pt_regs *regs,
 				  unsigned char buf[MAX_INSN_SIZE]);
-bool insn_decode(struct insn *insn, struct pt_regs *regs,
+bool insn_decode_from_regs(struct insn *insn, struct pt_regs *regs,
-		 unsigned char buf[MAX_INSN_SIZE], int buf_size);
+			   unsigned char buf[MAX_INSN_SIZE], int buf_size);
 
 #endif /* _ASM_X86_INSN_EVAL_H */

arch/x86/include/asm/insn.h

@@ -8,7 +8,7 @@
  */
 
 /* insn_attr_t is defined in inat.h */
-#include <asm/inat.h>
+#include <asm/inat.h> /* __ignore_sync_check__ */
 
 struct insn_field {
 	union {
@@ -87,13 +87,25 @@ struct insn {
 #define X86_VEX_M_MAX	0x1f			/* VEX3.M Maximum value */
 
 extern void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64);
-extern void insn_get_prefixes(struct insn *insn);
+extern int insn_get_prefixes(struct insn *insn);
-extern void insn_get_opcode(struct insn *insn);
+extern int insn_get_opcode(struct insn *insn);
-extern void insn_get_modrm(struct insn *insn);
+extern int insn_get_modrm(struct insn *insn);
-extern void insn_get_sib(struct insn *insn);
+extern int insn_get_sib(struct insn *insn);
-extern void insn_get_displacement(struct insn *insn);
+extern int insn_get_displacement(struct insn *insn);
-extern void insn_get_immediate(struct insn *insn);
+extern int insn_get_immediate(struct insn *insn);
-extern void insn_get_length(struct insn *insn);
+extern int insn_get_length(struct insn *insn);
+
+enum insn_mode {
+	INSN_MODE_32,
+	INSN_MODE_64,
+	/* Mode is determined by the current kernel build. */
+	INSN_MODE_KERN,
+	INSN_NUM_MODES,
+};
+
+extern int insn_decode(struct insn *insn, const void *kaddr, int buf_len, enum insn_mode m);
+
+#define insn_decode_kernel(_insn, _ptr) insn_decode((_insn), (_ptr), MAX_INSN_SIZE, INSN_MODE_KERN)
 
 /* Attribute will be determined after getting ModRM (for opcode groups) */
 static inline void insn_get_attribute(struct insn *insn)

arch/x86/include/asm/linkage.h

@@ -18,6 +18,28 @@
 #define __ALIGN_STR	__stringify(__ALIGN)
 #endif
 
+#if defined(CONFIG_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
+#define RET	jmp __x86_return_thunk
+#else /* CONFIG_RETPOLINE */
+#ifdef CONFIG_SLS
+#define RET	ret; int3
+#else
+#define RET	ret
+#endif
+#endif /* CONFIG_RETPOLINE */
+
+#else /* __ASSEMBLY__ */
+
+#if defined(CONFIG_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
+#define ASM_RET	"jmp __x86_return_thunk\n\t"
+#else /* CONFIG_RETPOLINE */
+#ifdef CONFIG_SLS
+#define ASM_RET	"ret; int3\n\t"
+#else
+#define ASM_RET	"ret\n\t"
+#endif
+#endif /* CONFIG_RETPOLINE */
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_X86_LINKAGE_H */

arch/x86/include/asm/msr-index.h

@@ -51,6 +51,8 @@
 #define SPEC_CTRL_STIBP			BIT(SPEC_CTRL_STIBP_SHIFT)	/* STIBP mask */
 #define SPEC_CTRL_SSBD_SHIFT		2	   /* Speculative Store Bypass Disable bit */
 #define SPEC_CTRL_SSBD			BIT(SPEC_CTRL_SSBD_SHIFT)	/* Speculative Store Bypass Disable */
+#define SPEC_CTRL_RRSBA_DIS_S_SHIFT	6	   /* Disable RRSBA behavior */
+#define SPEC_CTRL_RRSBA_DIS_S		BIT(SPEC_CTRL_RRSBA_DIS_S_SHIFT)
 
 #define MSR_IA32_PRED_CMD		0x00000049 /* Prediction Command */
 #define PRED_CMD_IBPB			BIT(0)	   /* Indirect Branch Prediction Barrier */
@@ -91,6 +93,7 @@
 #define MSR_IA32_ARCH_CAPABILITIES	0x0000010a
 #define ARCH_CAP_RDCL_NO		BIT(0)	/* Not susceptible to Meltdown */
 #define ARCH_CAP_IBRS_ALL		BIT(1)	/* Enhanced IBRS support */
+#define ARCH_CAP_RSBA			BIT(2)	/* RET may use alternative branch predictors */
 #define ARCH_CAP_SKIP_VMENTRY_L1DFLUSH	BIT(3)	/* Skip L1D flush on vmentry */
 #define ARCH_CAP_SSB_NO			BIT(4)	/*
 						 * Not susceptible to Speculative Store Bypass
@@ -138,6 +141,13 @@
 						 * bit available to control VERW
 						 * behavior.
 						 */
+#define ARCH_CAP_RRSBA			BIT(19)	/*
+						 * Indicates RET may use predictors
+						 * other than the RSB. With eIBRS
+						 * enabled predictions in kernel mode
+						 * are restricted to targets in
+						 * kernel.
+						 */
 
 #define MSR_IA32_FLUSH_CMD		0x0000010b
 #define L1D_FLUSH			BIT(0)	/*
@@ -507,6 +517,9 @@
 /* Fam 17h MSRs */
 #define MSR_F17H_IRPERF			0xc00000e9
 
+#define MSR_ZEN2_SPECTRAL_CHICKEN	0xc00110e3
+#define MSR_ZEN2_SPECTRAL_CHICKEN_BIT	BIT_ULL(1)
+
 /* Fam 16h MSRs */
 #define MSR_F16H_L2I_PERF_CTL		0xc0010230
 #define MSR_F16H_L2I_PERF_CTR		0xc0010231

arch/x86/include/asm/nospec-branch.h

@@ -5,12 +5,15 @@
 
 #include <linux/static_key.h>
 #include <linux/objtool.h>
+#include <linux/linkage.h>
 
 #include <asm/alternative.h>
-#include <asm/alternative-asm.h>
 #include <asm/cpufeatures.h>
 #include <asm/msr-index.h>
 #include <asm/unwind_hints.h>
+#include <asm/percpu.h>
+
+#define RETPOLINE_THUNK_SIZE	32
 
 /*
  * Fill the CPU return stack buffer.
@@ -73,6 +76,23 @@
 	.popsection
 .endm
 
+/*
+ * (ab)use RETPOLINE_SAFE on RET to annotate away 'bare' RET instructions
+ * vs RETBleed validation.
+ */
+#define ANNOTATE_UNRET_SAFE ANNOTATE_RETPOLINE_SAFE
+
+/*
+ * Abuse ANNOTATE_RETPOLINE_SAFE on a NOP to indicate UNRET_END, should
+ * eventually turn into it's own annotation.
+ */
+.macro ANNOTATE_UNRET_END
+#ifdef CONFIG_DEBUG_ENTRY
+	ANNOTATE_RETPOLINE_SAFE
+	nop
+#endif
+.endm
+
 /*
  * JMP_NOSPEC and CALL_NOSPEC macros can be used instead of a simple
  * indirect jmp/call which may be susceptible to the Spectre variant 2
@@ -81,7 +101,7 @@
 .macro JMP_NOSPEC reg:req
 #ifdef CONFIG_RETPOLINE
 	ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), \
-		      __stringify(jmp __x86_retpoline_\reg), X86_FEATURE_RETPOLINE, \
+		      __stringify(jmp __x86_indirect_thunk_\reg), X86_FEATURE_RETPOLINE, \
 		      __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), X86_FEATURE_RETPOLINE_LFENCE
 #else
 	jmp	*%\reg
@@ -91,7 +111,7 @@
 .macro CALL_NOSPEC reg:req
 #ifdef CONFIG_RETPOLINE
 	ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; call *%\reg), \
-		      __stringify(call __x86_retpoline_\reg), X86_FEATURE_RETPOLINE, \
+		      __stringify(call __x86_indirect_thunk_\reg), X86_FEATURE_RETPOLINE, \
 		      __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; call *%\reg), X86_FEATURE_RETPOLINE_LFENCE
 #else
 	call	*%\reg
@@ -103,10 +123,34 @@
   * monstrosity above, manually.
   */
 .macro FILL_RETURN_BUFFER reg:req nr:req ftr:req
-#ifdef CONFIG_RETPOLINE
 	ALTERNATIVE "jmp .Lskip_rsb_\@", "", \ftr
 	__FILL_RETURN_BUFFER(\reg,\nr,%_ASM_SP)
 .Lskip_rsb_\@:
+.endm
+
+#ifdef CONFIG_CPU_UNRET_ENTRY
+#define CALL_ZEN_UNTRAIN_RET	"call zen_untrain_ret"
+#else
+#define CALL_ZEN_UNTRAIN_RET	""
+#endif
+
+/*
+ * Mitigate RETBleed for AMD/Hygon Zen uarch. Requires KERNEL CR3 because the
+ * return thunk isn't mapped into the userspace tables (then again, AMD
+ * typically has NO_MELTDOWN).
+ *
+ * While zen_untrain_ret() doesn't clobber anything but requires stack,
+ * entry_ibpb() will clobber AX, CX, DX.
+ *
+ * As such, this must be placed after every *SWITCH_TO_KERNEL_CR3 at a point
+ * where we have a stack but before any RET instruction.
+ */
+.macro UNTRAIN_RET
+#if defined(CONFIG_CPU_UNRET_ENTRY) || defined(CONFIG_CPU_IBPB_ENTRY)
+	ANNOTATE_UNRET_END
+	ALTERNATIVE_2 "",						\
+	              CALL_ZEN_UNTRAIN_RET, X86_FEATURE_UNRET,		\
+		      "call entry_ibpb", X86_FEATURE_ENTRY_IBPB
 #endif
 .endm
 
@@ -118,7 +162,21 @@
 	_ASM_PTR " 999b\n\t"					\
 	".popsection\n\t"
 
+extern void __x86_return_thunk(void);
+extern void zen_untrain_ret(void);
+extern void entry_ibpb(void);
+
 #ifdef CONFIG_RETPOLINE
+
+typedef u8 retpoline_thunk_t[RETPOLINE_THUNK_SIZE];
+
+#define GEN(reg) \
+	extern retpoline_thunk_t __x86_indirect_thunk_ ## reg;
+#include <asm/GEN-for-each-reg.h>
+#undef GEN
+
+extern retpoline_thunk_t __x86_indirect_thunk_array[];
+
 #ifdef CONFIG_X86_64
 
 /*
@@ -129,7 +187,7 @@
 	ALTERNATIVE_2(						\
 	ANNOTATE_RETPOLINE_SAFE					\
 	"call *%[thunk_target]\n",				\
-	"call __x86_retpoline_%V[thunk_target]\n",		\
+	"call __x86_indirect_thunk_%V[thunk_target]\n",		\
 	X86_FEATURE_RETPOLINE,					\
 	"lfence;\n"						\
 	ANNOTATE_RETPOLINE_SAFE					\
@@ -181,6 +239,7 @@ enum spectre_v2_mitigation {
 	SPECTRE_V2_EIBRS,
 	SPECTRE_V2_EIBRS_RETPOLINE,
 	SPECTRE_V2_EIBRS_LFENCE,
+	SPECTRE_V2_IBRS,
 };
 
 /* The indirect branch speculation control variants */
@@ -223,6 +282,9 @@ static inline void indirect_branch_prediction_barrier(void)
 
 /* The Intel SPEC CTRL MSR base value cache */
 extern u64 x86_spec_ctrl_base;
+DECLARE_PER_CPU(u64, x86_spec_ctrl_current);
+extern void write_spec_ctrl_current(u64 val, bool force);
+extern u64 spec_ctrl_current(void);
 
 /*
  * With retpoline, we must use IBRS to restrict branch prediction
@@ -232,18 +294,16 @@ extern u64 x86_spec_ctrl_base;
  */
 #define firmware_restrict_branch_speculation_start()			\
 do {									\
-	u64 val = x86_spec_ctrl_base | SPEC_CTRL_IBRS;			\
-									\
 	preempt_disable();						\
-	alternative_msr_write(MSR_IA32_SPEC_CTRL, val,			\
+	alternative_msr_write(MSR_IA32_SPEC_CTRL,			\
+			      spec_ctrl_current() | SPEC_CTRL_IBRS,	\
 			      X86_FEATURE_USE_IBRS_FW);			\
 } while (0)
 
 #define firmware_restrict_branch_speculation_end()			\
 do {									\
-	u64 val = x86_spec_ctrl_base;					\
+	alternative_msr_write(MSR_IA32_SPEC_CTRL,			\
-									\
+			      spec_ctrl_current(),			\
-	alternative_msr_write(MSR_IA32_SPEC_CTRL, val,			\
 			      X86_FEATURE_USE_IBRS_FW);			\
 	preempt_enable();						\
 } while (0)
@@ -306,63 +366,4 @@ static inline void mds_idle_clear_cpu_buffers(void)
 
 #endif /* __ASSEMBLY__ */
 
-/*
- * Below is used in the eBPF JIT compiler and emits the byte sequence
- * for the following assembly:
- *
- * With retpolines configured:
- *
- *    callq do_rop
- *  spec_trap:
- *    pause
- *    lfence
- *    jmp spec_trap
- *  do_rop:
- *    mov %rcx,(%rsp) for x86_64
- *    mov %edx,(%esp) for x86_32
- *    retq
- *
- * Without retpolines configured:
- *
- *    jmp *%rcx for x86_64
- *    jmp *%edx for x86_32
- */
-#ifdef CONFIG_RETPOLINE
-# ifdef CONFIG_X86_64
-#  define RETPOLINE_RCX_BPF_JIT_SIZE	17
-#  define RETPOLINE_RCX_BPF_JIT()				\
-do {								\
-	EMIT1_off32(0xE8, 7);	 /* callq do_rop */		\
-	/* spec_trap: */					\
-	EMIT2(0xF3, 0x90);       /* pause */			\
-	EMIT3(0x0F, 0xAE, 0xE8); /* lfence */			\
-	EMIT2(0xEB, 0xF9);       /* jmp spec_trap */		\
-	/* do_rop: */						\
-	EMIT4(0x48, 0x89, 0x0C, 0x24); /* mov %rcx,(%rsp) */	\
-	EMIT1(0xC3);             /* retq */			\
-} while (0)
-# else /* !CONFIG_X86_64 */
-#  define RETPOLINE_EDX_BPF_JIT()				\
-do {								\
-	EMIT1_off32(0xE8, 7);	 /* call do_rop */		\
-	/* spec_trap: */					\
-	EMIT2(0xF3, 0x90);       /* pause */			\
-	EMIT3(0x0F, 0xAE, 0xE8); /* lfence */			\
-	EMIT2(0xEB, 0xF9);       /* jmp spec_trap */		\
-	/* do_rop: */						\
-	EMIT3(0x89, 0x14, 0x24); /* mov %edx,(%esp) */		\
-	EMIT1(0xC3);             /* ret */			\
-} while (0)
-# endif
-#else /* !CONFIG_RETPOLINE */
-# ifdef CONFIG_X86_64
-#  define RETPOLINE_RCX_BPF_JIT_SIZE	2
-#  define RETPOLINE_RCX_BPF_JIT()				\
-	EMIT2(0xFF, 0xE1);       /* jmp *%rcx */
-# else /* !CONFIG_X86_64 */
-#  define RETPOLINE_EDX_BPF_JIT()				\
-	EMIT2(0xFF, 0xE2)        /* jmp *%edx */
-# endif
-#endif
-
 #endif /* _ASM_X86_NOSPEC_BRANCH_H_ */

arch/x86/include/asm/paravirt.h

@@ -630,7 +630,7 @@ bool __raw_callee_save___native_vcpu_is_preempted(long cpu);
 	    "call " #func ";"						\
 	    PV_RESTORE_ALL_CALLER_REGS					\
 	    FRAME_END							\
-	    "ret;"							\
+	    ASM_RET							\
 	    ".size " PV_THUNK_NAME(func) ", .-" PV_THUNK_NAME(func) ";"	\
 	    ".popsection")
 

arch/x86/include/asm/qspinlock_paravirt.h

@@ -48,7 +48,7 @@ asm    (".pushsection .text;"
 	"jne   .slowpath;"
 	"pop   %rdx;"
 	FRAME_END
-	"ret;"
+	ASM_RET
 	".slowpath: "
 	"push   %rsi;"
 	"movzbl %al,%esi;"
@@ -56,7 +56,7 @@ asm    (".pushsection .text;"
 	"pop    %rsi;"
 	"pop    %rdx;"
 	FRAME_END
-	"ret;"
+	ASM_RET
 	".size " PV_UNLOCK ", .-" PV_UNLOCK ";"
 	".popsection");
 

arch/x86/include/asm/smap.h

@@ -11,6 +11,7 @@
 
 #include <asm/nops.h>
 #include <asm/cpufeatures.h>
+#include <asm/alternative.h>
 
 /* "Raw" instruction opcodes */
 #define __ASM_CLAC	".byte 0x0f,0x01,0xca"
@@ -18,8 +19,6 @@
 
 #ifdef __ASSEMBLY__
 
-#include <asm/alternative-asm.h>
-
 #ifdef CONFIG_X86_SMAP
 
 #define ASM_CLAC \
@@ -37,8 +36,6 @@
 
 #else /* __ASSEMBLY__ */
 
-#include <asm/alternative.h>
-
 #ifdef CONFIG_X86_SMAP
 
 static __always_inline void clac(void)

arch/x86/include/asm/static_call.h

@@ -21,6 +21,16 @@
  * relative displacement across sections.
  */
 
+/*
+ * The trampoline is 8 bytes and of the general form:
+ *
+ *   jmp.d32 \func
+ *   ud1 %esp, %ecx
+ *
+ * That trailing #UD provides both a speculation stop and serves as a unique
+ * 3 byte signature identifying static call trampolines. Also see tramp_ud[]
+ * and __static_call_fixup().
+ */
 #define __ARCH_DEFINE_STATIC_CALL_TRAMP(name, insns)			\
 	asm(".pushsection .static_call.text, \"ax\"		\n"	\
 	    ".align 4						\n"	\
@@ -34,8 +44,13 @@
 #define ARCH_DEFINE_STATIC_CALL_TRAMP(name, func)			\
 	__ARCH_DEFINE_STATIC_CALL_TRAMP(name, ".byte 0xe9; .long " #func " - (. + 4)")
 
+#ifdef CONFIG_RETHUNK
 #define ARCH_DEFINE_STATIC_CALL_NULL_TRAMP(name)			\
-	__ARCH_DEFINE_STATIC_CALL_TRAMP(name, "ret; nop; nop; nop; nop")
+	__ARCH_DEFINE_STATIC_CALL_TRAMP(name, "jmp __x86_return_thunk")
+#else
+#define ARCH_DEFINE_STATIC_CALL_NULL_TRAMP(name)			\
+	__ARCH_DEFINE_STATIC_CALL_TRAMP(name, "ret; int3; nop; nop; nop")
+#endif
 
 
 #define ARCH_ADD_TRAMP_KEY(name)					\
@@ -44,4 +59,6 @@
 	    ".long " STATIC_CALL_KEY_STR(name) " - .		\n"	\
 	    ".popsection					\n")
 
+extern bool __static_call_fixup(void *tramp, u8 op, void *dest);
+
 #endif /* _ASM_STATIC_CALL_H */

arch/x86/include/asm/unwind_hints.h

@@ -8,7 +8,11 @@
 #ifdef __ASSEMBLY__
 
 .macro UNWIND_HINT_EMPTY
-	UNWIND_HINT sp_reg=ORC_REG_UNDEFINED type=UNWIND_HINT_TYPE_CALL end=1
+	UNWIND_HINT type=UNWIND_HINT_TYPE_CALL end=1
+.endm
+
+.macro UNWIND_HINT_ENTRY
+	UNWIND_HINT type=UNWIND_HINT_TYPE_ENTRY end=1
 .endm
 
 .macro UNWIND_HINT_REGS base=%rsp offset=0 indirect=0 extra=1 partial=0
@@ -48,17 +52,16 @@
 	UNWIND_HINT_REGS base=\base offset=\offset partial=1
 .endm
 
-.macro UNWIND_HINT_FUNC sp_offset=8
+.macro UNWIND_HINT_FUNC
-	UNWIND_HINT sp_reg=ORC_REG_SP sp_offset=\sp_offset type=UNWIND_HINT_TYPE_CALL
+	UNWIND_HINT sp_reg=ORC_REG_SP sp_offset=8 type=UNWIND_HINT_TYPE_FUNC
 .endm
 
-/*
+.macro UNWIND_HINT_SAVE
- * RET_OFFSET: Used on instructions that terminate a function; mostly RETURN
+	UNWIND_HINT type=UNWIND_HINT_TYPE_SAVE
- * and sibling calls. On these, sp_offset denotes the expected offset from
+.endm
- * initial_func_cfi.
+
- */
+.macro UNWIND_HINT_RESTORE
-.macro UNWIND_HINT_RET_OFFSET sp_offset=8
+	UNWIND_HINT type=UNWIND_HINT_TYPE_RESTORE
-	UNWIND_HINT sp_reg=ORC_REG_SP type=UNWIND_HINT_TYPE_RET_OFFSET sp_offset=\sp_offset
 .endm
 
 #endif /* __ASSEMBLY__ */

arch/x86/kernel/acpi/wakeup_32.S

@@ -60,7 +60,7 @@ save_registers:
 	popl	saved_context_eflags
 
 	movl	$ret_point, saved_eip
-	ret
+	RET
 
 
 restore_registers:
@@ -70,7 +70,7 @@ restore_registers:
 	movl	saved_context_edi, %edi
 	pushl	saved_context_eflags
 	popfl
-	ret
+	RET
 
 SYM_CODE_START(do_suspend_lowlevel)
 	call	save_processor_state
@@ -86,7 +86,7 @@ SYM_CODE_START(do_suspend_lowlevel)
 ret_point:
 	call	restore_registers
 	call	restore_processor_state
-	ret
+	RET
 SYM_CODE_END(do_suspend_lowlevel)
 
 .data

arch/x86/kernel/alternative.c

@@ -28,6 +28,7 @@
 #include <asm/insn.h>
 #include <asm/io.h>
 #include <asm/fixmap.h>
+#include <asm/asm-prototypes.h>
 
 int __read_mostly alternatives_patched;
 
@@ -268,6 +269,8 @@ static void __init_or_module add_nops(void *insns, unsigned int len)
 	}
 }
 
+extern s32 __retpoline_sites[], __retpoline_sites_end[];
+extern s32 __return_sites[], __return_sites_end[];
 extern struct alt_instr __alt_instructions[], __alt_instructions_end[];
 extern s32 __smp_locks[], __smp_locks_end[];
 void text_poke_early(void *addr, const void *opcode, size_t len);
@@ -337,26 +340,70 @@ done:
 		n_dspl, (unsigned long)orig_insn + n_dspl + repl_len);
 }
 
+/*
+ * optimize_nops_range() - Optimize a sequence of single byte NOPs (0x90)
+ *
+ * @instr: instruction byte stream
+ * @instrlen: length of the above
+ * @off: offset within @instr where the first NOP has been detected
+ *
+ * Return: number of NOPs found (and replaced).
+ */
+static __always_inline int optimize_nops_range(u8 *instr, u8 instrlen, int off)
+{
+	unsigned long flags;
+	int i = off, nnops;
+
+	while (i < instrlen) {
+		if (instr[i] != 0x90)
+			break;
+
+		i++;
+	}
+
+	nnops = i - off;
+
+	if (nnops <= 1)
+		return nnops;
+
+	local_irq_save(flags);
+	add_nops(instr + off, nnops);
+	local_irq_restore(flags);
+
+	DUMP_BYTES(instr, instrlen, "%px: [%d:%d) optimized NOPs: ", instr, off, i);
+
+	return nnops;
+}
+
 /*
  * "noinline" to cause control flow change and thus invalidate I$ and
  * cause refetch after modification.
  */
-static void __init_or_module noinline optimize_nops(struct alt_instr *a, u8 *instr)
+static void __init_or_module noinline optimize_nops(u8 *instr, size_t len)
 {
-	unsigned long flags;
+	struct insn insn;
-	int i;
+	int i = 0;
 
-	for (i = 0; i < a->padlen; i++) {
+	/*
-		if (instr[i] != 0x90)
+	 * Jump over the non-NOP insns and optimize single-byte NOPs into bigger
+	 * ones.
+	 */
+	for (;;) {
+		if (insn_decode_kernel(&insn, &instr[i]))
+			return;
+
+		/*
+		 * See if this and any potentially following NOPs can be
+		 * optimized.
+		 */
+		if (insn.length == 1 && insn.opcode.bytes[0] == 0x90)
+			i += optimize_nops_range(instr, len, i);
+		else
+			i += insn.length;
+
+		if (i >= len)
 			return;
 	}
-
-	local_irq_save(flags);
-	add_nops(instr + (a->instrlen - a->padlen), a->padlen);
-	local_irq_restore(flags);
-
-	DUMP_BYTES(instr, a->instrlen, "%px: [%d:%d) optimized NOPs: ",
-		   instr, a->instrlen - a->padlen, a->padlen);
 }
 
 /*
@@ -388,23 +435,29 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start,
 	 */
 	for (a = start; a < end; a++) {
 		int insn_buff_sz = 0;
+		/* Mask away "NOT" flag bit for feature to test. */
+		u16 feature = a->cpuid & ~ALTINSTR_FLAG_INV;
 
 		instr = (u8 *)&a->instr_offset + a->instr_offset;
 		replacement = (u8 *)&a->repl_offset + a->repl_offset;
 		BUG_ON(a->instrlen > sizeof(insn_buff));
-		BUG_ON(a->cpuid >= (NCAPINTS + NBUGINTS) * 32);
+		BUG_ON(feature >= (NCAPINTS + NBUGINTS) * 32);
-		if (!boot_cpu_has(a->cpuid)) {
-			if (a->padlen > 1)
-				optimize_nops(a, instr);
 
-			continue;
+		/*
-		}
+		 * Patch if either:
+		 * - feature is present
+		 * - feature not present but ALTINSTR_FLAG_INV is set to mean,
+		 *   patch if feature is *NOT* present.
+		 */
+		if (!boot_cpu_has(feature) == !(a->cpuid & ALTINSTR_FLAG_INV))
+			goto next;
 
-		DPRINTK("feat: %d*32+%d, old: (%pS (%px) len: %d), repl: (%px, len: %d), pad: %d",
+		DPRINTK("feat: %s%d*32+%d, old: (%pS (%px) len: %d), repl: (%px, len: %d)",
-			a->cpuid >> 5,
+			(a->cpuid & ALTINSTR_FLAG_INV) ? "!" : "",
-			a->cpuid & 0x1f,
+			feature >> 5,
+			feature & 0x1f,
 			instr, instr, a->instrlen,
-			replacement, a->replacementlen, a->padlen);
+			replacement, a->replacementlen);
 
 		DUMP_BYTES(instr, a->instrlen, "%px: old_insn: ", instr);
 		DUMP_BYTES(replacement, a->replacementlen, "%px: rpl_insn: ", replacement);
@@ -428,17 +481,260 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start,
 		if (a->replacementlen && is_jmp(replacement[0]))
 			recompute_jump(a, instr, replacement, insn_buff);
 
-		if (a->instrlen > a->replacementlen) {
+		for (; insn_buff_sz < a->instrlen; insn_buff_sz++)
-			add_nops(insn_buff + a->replacementlen,
+			insn_buff[insn_buff_sz] = 0x90;
-				 a->instrlen - a->replacementlen);
+
-			insn_buff_sz += a->instrlen - a->replacementlen;
-		}
 		DUMP_BYTES(insn_buff, insn_buff_sz, "%px: final_insn: ", instr);
 
 		text_poke_early(instr, insn_buff, insn_buff_sz);
+
+next:
+		optimize_nops(instr, a->instrlen);
 	}
 }
 
+#if defined(CONFIG_RETPOLINE) && defined(CONFIG_STACK_VALIDATION)
+
+/*
+ * CALL/JMP *%\reg
+ */
+static int emit_indirect(int op, int reg, u8 *bytes)
+{
+	int i = 0;
+	u8 modrm;
+
+	switch (op) {
+	case CALL_INSN_OPCODE:
+		modrm = 0x10; /* Reg = 2; CALL r/m */
+		break;
+
+	case JMP32_INSN_OPCODE:
+		modrm = 0x20; /* Reg = 4; JMP r/m */
+		break;
+
+	default:
+		WARN_ON_ONCE(1);
+		return -1;
+	}
+
+	if (reg >= 8) {
+		bytes[i++] = 0x41; /* REX.B prefix */
+		reg -= 8;
+	}
+
+	modrm |= 0xc0; /* Mod = 3 */
+	modrm += reg;
+
+	bytes[i++] = 0xff; /* opcode */
+	bytes[i++] = modrm;
+
+	return i;
+}
+
+/*
+ * Rewrite the compiler generated retpoline thunk calls.
+ *
+ * For spectre_v2=off (!X86_FEATURE_RETPOLINE), rewrite them into immediate
+ * indirect instructions, avoiding the extra indirection.
+ *
+ * For example, convert:
+ *
+ *   CALL __x86_indirect_thunk_\reg
+ *
+ * into:
+ *
+ *   CALL *%\reg
+ *
+ * It also tries to inline spectre_v2=retpoline,amd when size permits.
+ */
+static int patch_retpoline(void *addr, struct insn *insn, u8 *bytes)
+{
+	retpoline_thunk_t *target;
+	int reg, ret, i = 0;
+	u8 op, cc;
+
+	target = addr + insn->length + insn->immediate.value;
+	reg = target - __x86_indirect_thunk_array;
+
+	if (WARN_ON_ONCE(reg & ~0xf))
+		return -1;
+
+	/* If anyone ever does: CALL/JMP *%rsp, we're in deep trouble. */
+	BUG_ON(reg == 4);
+
+	if (cpu_feature_enabled(X86_FEATURE_RETPOLINE) &&
+	    !cpu_feature_enabled(X86_FEATURE_RETPOLINE_LFENCE))
+		return -1;
+
+	op = insn->opcode.bytes[0];
+
+	/*
+	 * Convert:
+	 *
+	 *   Jcc.d32 __x86_indirect_thunk_\reg
+	 *
+	 * into:
+	 *
+	 *   Jncc.d8 1f
+	 *   [ LFENCE ]
+	 *   JMP *%\reg
+	 *   [ NOP ]
+	 * 1:
+	 */
+	/* Jcc.d32 second opcode byte is in the range: 0x80-0x8f */
+	if (op == 0x0f && (insn->opcode.bytes[1] & 0xf0) == 0x80) {
+		cc = insn->opcode.bytes[1] & 0xf;
+		cc ^= 1; /* invert condition */
+
+		bytes[i++] = 0x70 + cc;        /* Jcc.d8 */
+		bytes[i++] = insn->length - 2; /* sizeof(Jcc.d8) == 2 */
+
+		/* Continue as if: JMP.d32 __x86_indirect_thunk_\reg */
+		op = JMP32_INSN_OPCODE;
+	}
+
+	/*
+	 * For RETPOLINE_AMD: prepend the indirect CALL/JMP with an LFENCE.
+	 */
+	if (cpu_feature_enabled(X86_FEATURE_RETPOLINE_LFENCE)) {
+		bytes[i++] = 0x0f;
+		bytes[i++] = 0xae;
+		bytes[i++] = 0xe8; /* LFENCE */
+	}
+
+	ret = emit_indirect(op, reg, bytes + i);
+	if (ret < 0)
+		return ret;
+	i += ret;
+
+	for (; i < insn->length;)
+		bytes[i++] = 0x90;
+
+	return i;
+}
+
+/*
+ * Generated by 'objtool --retpoline'.
+ */
+void __init_or_module noinline apply_retpolines(s32 *start, s32 *end)
+{
+	s32 *s;
+
+	for (s = start; s < end; s++) {
+		void *addr = (void *)s + *s;
+		struct insn insn;
+		int len, ret;
+		u8 bytes[16];
+		u8 op1, op2;
+
+		ret = insn_decode_kernel(&insn, addr);
+		if (WARN_ON_ONCE(ret < 0))
+			continue;
+
+		op1 = insn.opcode.bytes[0];
+		op2 = insn.opcode.bytes[1];
+
+		switch (op1) {
+		case CALL_INSN_OPCODE:
+		case JMP32_INSN_OPCODE:
+			break;
+
+		case 0x0f: /* escape */
+			if (op2 >= 0x80 && op2 <= 0x8f)
+				break;
+			fallthrough;
+		default:
+			WARN_ON_ONCE(1);
+			continue;
+		}
+
+		DPRINTK("retpoline at: %pS (%px) len: %d to: %pS",
+			addr, addr, insn.length,
+			addr + insn.length + insn.immediate.value);
+
+		len = patch_retpoline(addr, &insn, bytes);
+		if (len == insn.length) {
+			optimize_nops(bytes, len);
+			DUMP_BYTES(((u8*)addr),  len, "%px: orig: ", addr);
+			DUMP_BYTES(((u8*)bytes), len, "%px: repl: ", addr);
+			text_poke_early(addr, bytes, len);
+		}
+	}
+}
+
+#ifdef CONFIG_RETHUNK
+/*
+ * Rewrite the compiler generated return thunk tail-calls.
+ *
+ * For example, convert:
+ *
+ *   JMP __x86_return_thunk
+ *
+ * into:
+ *
+ *   RET
+ */
+static int patch_return(void *addr, struct insn *insn, u8 *bytes)
+{
+	int i = 0;
+
+	if (cpu_feature_enabled(X86_FEATURE_RETHUNK))
+		return -1;
+
+	bytes[i++] = RET_INSN_OPCODE;
+
+	for (; i < insn->length;)
+		bytes[i++] = INT3_INSN_OPCODE;
+
+	return i;
+}
+
+void __init_or_module noinline apply_returns(s32 *start, s32 *end)
+{
+	s32 *s;
+
+	for (s = start; s < end; s++) {
+		void *dest = NULL, *addr = (void *)s + *s;
+		struct insn insn;
+		int len, ret;
+		u8 bytes[16];
+		u8 op;
+
+		ret = insn_decode_kernel(&insn, addr);
+		if (WARN_ON_ONCE(ret < 0))
+			continue;
+
+		op = insn.opcode.bytes[0];
+		if (op == JMP32_INSN_OPCODE)
+			dest = addr + insn.length + insn.immediate.value;
+
+		if (__static_call_fixup(addr, op, dest) ||
+		    WARN_ON_ONCE(dest != &__x86_return_thunk))
+			continue;
+
+		DPRINTK("return thunk at: %pS (%px) len: %d to: %pS",
+			addr, addr, insn.length,
+			addr + insn.length + insn.immediate.value);
+
+		len = patch_return(addr, &insn, bytes);
+		if (len == insn.length) {
+			DUMP_BYTES(((u8*)addr),  len, "%px: orig: ", addr);
+			DUMP_BYTES(((u8*)bytes), len, "%px: repl: ", addr);
+			text_poke_early(addr, bytes, len);
+		}
+	}
+}
+#else
+void __init_or_module noinline apply_returns(s32 *start, s32 *end) { }
+#endif /* CONFIG_RETHUNK */
+
+#else /* !RETPOLINES || !CONFIG_STACK_VALIDATION */
+
+void __init_or_module noinline apply_retpolines(s32 *start, s32 *end) { }
+void __init_or_module noinline apply_returns(s32 *start, s32 *end) { }
+
+#endif /* CONFIG_RETPOLINE && CONFIG_STACK_VALIDATION */
+
 #ifdef CONFIG_SMP
 static void alternatives_smp_lock(const s32 *start, const s32 *end,
 				  u8 *text, u8 *text_end)
@@ -710,6 +1006,13 @@ void __init alternative_instructions(void)
 	 * patching.
 	 */
 
+	/*
+	 * Rewrite the retpolines, must be done before alternatives since
+	 * those can rewrite the retpoline thunks.
+	 */
+	apply_retpolines(__retpoline_sites, __retpoline_sites_end);
+	apply_returns(__return_sites, __return_sites_end);
+
 	apply_alternatives(__alt_instructions, __alt_instructions_end);
 
 #ifdef CONFIG_SMP
@@ -996,10 +1299,13 @@ void text_poke_sync(void)
 }
 
 struct text_poke_loc {
-	s32 rel_addr; /* addr := _stext + rel_addr */
+	/* addr := _stext + rel_addr */
-	s32 rel32;
+	s32 rel_addr;
+	s32 disp;
+	u8 len;
 	u8 opcode;
 	const u8 text[POKE_MAX_OPCODE_SIZE];
+	/* see text_poke_bp_batch() */
 	u8 old;
 };
 
@@ -1014,7 +1320,8 @@ static struct bp_patching_desc *bp_desc;
 static __always_inline
 struct bp_patching_desc *try_get_desc(struct bp_patching_desc **descp)
 {
-	struct bp_patching_desc *desc = __READ_ONCE(*descp); /* rcu_dereference */
+	/* rcu_dereference */
+	struct bp_patching_desc *desc = __READ_ONCE(*descp);
 
 	if (!desc || !arch_atomic_inc_not_zero(&desc->refs))
 		return NULL;
@@ -1048,7 +1355,7 @@ noinstr int poke_int3_handler(struct pt_regs *regs)
 {
 	struct bp_patching_desc *desc;
 	struct text_poke_loc *tp;
-	int len, ret = 0;
+	int ret = 0;
 	void *ip;
 
 	if (user_mode(regs))
@@ -1088,8 +1395,7 @@ noinstr int poke_int3_handler(struct pt_regs *regs)
 			goto out_put;
 	}
 
-	len = text_opcode_size(tp->opcode);
+	ip += tp->len;
-	ip += len;
 
 	switch (tp->opcode) {
 	case INT3_INSN_OPCODE:
@@ -1104,12 +1410,12 @@ noinstr int poke_int3_handler(struct pt_regs *regs)
 		break;
 
 	case CALL_INSN_OPCODE:
-		int3_emulate_call(regs, (long)ip + tp->rel32);
+		int3_emulate_call(regs, (long)ip + tp->disp);
 		break;
 
 	case JMP32_INSN_OPCODE:
 	case JMP8_INSN_OPCODE:
-		int3_emulate_jmp(regs, (long)ip + tp->rel32);
+		int3_emulate_jmp(regs, (long)ip + tp->disp);
 		break;
 
 	default:
@@ -1184,7 +1490,7 @@ static void text_poke_bp_batch(struct text_poke_loc *tp, unsigned int nr_entries
 	 */
 	for (do_sync = 0, i = 0; i < nr_entries; i++) {
 		u8 old[POKE_MAX_OPCODE_SIZE] = { tp[i].old, };
-		int len = text_opcode_size(tp[i].opcode);
+		int len = tp[i].len;
 
 		if (len - INT3_INSN_SIZE > 0) {
 			memcpy(old + INT3_INSN_SIZE,
@@ -1261,20 +1567,36 @@ static void text_poke_loc_init(struct text_poke_loc *tp, void *addr,
 			       const void *opcode, size_t len, const void *emulate)
 {
 	struct insn insn;
+	int ret, i;
 
 	memcpy((void *)tp->text, opcode, len);
 	if (!emulate)
 		emulate = opcode;
 
-	kernel_insn_init(&insn, emulate, MAX_INSN_SIZE);
+	ret = insn_decode_kernel(&insn, emulate);
-	insn_get_length(&insn);
+	BUG_ON(ret < 0);
-
-	BUG_ON(!insn_complete(&insn));
-	BUG_ON(len != insn.length);
 
 	tp->rel_addr = addr - (void *)_stext;
+	tp->len = len;
 	tp->opcode = insn.opcode.bytes[0];
 
+	switch (tp->opcode) {
+	case RET_INSN_OPCODE:
+	case JMP32_INSN_OPCODE:
+	case JMP8_INSN_OPCODE:
+		/*
+		 * Control flow instructions without implied execution of the
+		 * next instruction can be padded with INT3.
+		 */
+		for (i = insn.length; i < len; i++)
+			BUG_ON(tp->text[i] != INT3_INSN_OPCODE);
+		break;
+
+	default:
+		BUG_ON(len != insn.length);
+	};
+
+
 	switch (tp->opcode) {
 	case INT3_INSN_OPCODE:
 	case RET_INSN_OPCODE:
@@ -1283,7 +1605,7 @@ static void text_poke_loc_init(struct text_poke_loc *tp, void *addr,
 	case CALL_INSN_OPCODE:
 	case JMP32_INSN_OPCODE:
 	case JMP8_INSN_OPCODE:
-		tp->rel32 = insn.immediate.value;
+		tp->disp = insn.immediate.value;
 		break;
 
 	default: /* assume NOP */
@@ -1291,13 +1613,13 @@ static void text_poke_loc_init(struct text_poke_loc *tp, void *addr,
 		case 2: /* NOP2 -- emulate as JMP8+0 */
 			BUG_ON(memcmp(emulate, ideal_nops[len], len));
 			tp->opcode = JMP8_INSN_OPCODE;
-			tp->rel32 = 0;
+			tp->disp = 0;
 			break;
 
 		case 5: /* NOP5 -- emulate as JMP32+0 */
 			BUG_ON(memcmp(emulate, ideal_nops[NOP_ATOMIC5], len));
 			tp->opcode = JMP32_INSN_OPCODE;
-			tp->rel32 = 0;
+			tp->disp = 0;
 			break;
 
 		default: /* unknown instruction */

arch/x86/kernel/cpu/amd.c

@@ -914,6 +914,28 @@ static void init_amd_bd(struct cpuinfo_x86 *c)
 	clear_rdrand_cpuid_bit(c);
 }
 
+void init_spectral_chicken(struct cpuinfo_x86 *c)
+{
+#ifdef CONFIG_CPU_UNRET_ENTRY
+	u64 value;
+
+	/*
+	 * On Zen2 we offer this chicken (bit) on the altar of Speculation.
+	 *
+	 * This suppresses speculation from the middle of a basic block, i.e. it
+	 * suppresses non-branch predictions.
+	 *
+	 * We use STIBP as a heuristic to filter out Zen2 from the rest of F17H
+	 */
+	if (!cpu_has(c, X86_FEATURE_HYPERVISOR) && cpu_has(c, X86_FEATURE_AMD_STIBP)) {
+		if (!rdmsrl_safe(MSR_ZEN2_SPECTRAL_CHICKEN, &value)) {
+			value |= MSR_ZEN2_SPECTRAL_CHICKEN_BIT;
+			wrmsrl_safe(MSR_ZEN2_SPECTRAL_CHICKEN, value);
+		}
+	}
+#endif
+}
+
 static void init_amd_zn(struct cpuinfo_x86 *c)
 {
 	set_cpu_cap(c, X86_FEATURE_ZEN);
@@ -922,12 +944,21 @@ static void init_amd_zn(struct cpuinfo_x86 *c)
 	node_reclaim_distance = 32;
 #endif
 
-	/*
+	/* Fix up CPUID bits, but only if not virtualised. */
-	 * Fix erratum 1076: CPB feature bit not being set in CPUID.
+	if (!cpu_has(c, X86_FEATURE_HYPERVISOR)) {
-	 * Always set it, except when running under a hypervisor.
+
-	 */
+		/* Erratum 1076: CPB feature bit not being set in CPUID. */
-	if (!cpu_has(c, X86_FEATURE_HYPERVISOR) && !cpu_has(c, X86_FEATURE_CPB))
+		if (!cpu_has(c, X86_FEATURE_CPB))
-		set_cpu_cap(c, X86_FEATURE_CPB);
+			set_cpu_cap(c, X86_FEATURE_CPB);
+
+		/*
+		 * Zen3 (Fam19 model < 0x10) parts are not susceptible to
+		 * Branch Type Confusion, but predate the allocation of the
+		 * BTC_NO bit.
+		 */
+		if (c->x86 == 0x19 && !cpu_has(c, X86_FEATURE_BTC_NO))
+			set_cpu_cap(c, X86_FEATURE_BTC_NO);
+	}
 }
 
 static void init_amd(struct cpuinfo_x86 *c)
@@ -959,7 +990,8 @@ static void init_amd(struct cpuinfo_x86 *c)
 	case 0x12: init_amd_ln(c); break;
 	case 0x15: init_amd_bd(c); break;
 	case 0x16: init_amd_jg(c); break;
-	case 0x17: fallthrough;
+	case 0x17: init_spectral_chicken(c);
+		   fallthrough;
 	case 0x19: init_amd_zn(c); break;
 	}
 

arch/x86/kernel/cpu/bugs.c

@@ -38,6 +38,8 @@
 
 static void __init spectre_v1_select_mitigation(void);
 static void __init spectre_v2_select_mitigation(void);
+static void __init retbleed_select_mitigation(void);
+static void __init spectre_v2_user_select_mitigation(void);
 static void __init ssb_select_mitigation(void);
 static void __init l1tf_select_mitigation(void);
 static void __init mds_select_mitigation(void);
@@ -47,16 +49,40 @@ static void __init taa_select_mitigation(void);
 static void __init mmio_select_mitigation(void);
 static void __init srbds_select_mitigation(void);
 
-/* The base value of the SPEC_CTRL MSR that always has to be preserved. */
+/* The base value of the SPEC_CTRL MSR without task-specific bits set */
 u64 x86_spec_ctrl_base;
 EXPORT_SYMBOL_GPL(x86_spec_ctrl_base);
+
+/* The current value of the SPEC_CTRL MSR with task-specific bits set */
+DEFINE_PER_CPU(u64, x86_spec_ctrl_current);
+EXPORT_SYMBOL_GPL(x86_spec_ctrl_current);
+
 static DEFINE_MUTEX(spec_ctrl_mutex);
 
 /*
- * The vendor and possibly platform specific bits which can be modified in
+ * Keep track of the SPEC_CTRL MSR value for the current task, which may differ
- * x86_spec_ctrl_base.
+ * from x86_spec_ctrl_base due to STIBP/SSB in __speculation_ctrl_update().
  */
-static u64 __ro_after_init x86_spec_ctrl_mask = SPEC_CTRL_IBRS;
+void write_spec_ctrl_current(u64 val, bool force)
+{
+	if (this_cpu_read(x86_spec_ctrl_current) == val)
+		return;
+
+	this_cpu_write(x86_spec_ctrl_current, val);
+
+	/*
+	 * When KERNEL_IBRS this MSR is written on return-to-user, unless
+	 * forced the update can be delayed until that time.
+	 */
+	if (force || !cpu_feature_enabled(X86_FEATURE_KERNEL_IBRS))
+		wrmsrl(MSR_IA32_SPEC_CTRL, val);
+}
+
+u64 spec_ctrl_current(void)
+{
+	return this_cpu_read(x86_spec_ctrl_current);
+}
+EXPORT_SYMBOL_GPL(spec_ctrl_current);
 
 /*
  * AMD specific MSR info for Speculative Store Bypass control.
@@ -106,13 +132,21 @@ void __init check_bugs(void)
 	if (boot_cpu_has(X86_FEATURE_MSR_SPEC_CTRL))
 		rdmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
 
-	/* Allow STIBP in MSR_SPEC_CTRL if supported */
-	if (boot_cpu_has(X86_FEATURE_STIBP))
-		x86_spec_ctrl_mask |= SPEC_CTRL_STIBP;
-
 	/* Select the proper CPU mitigations before patching alternatives: */
 	spectre_v1_select_mitigation();
 	spectre_v2_select_mitigation();
+	/*
+	 * retbleed_select_mitigation() relies on the state set by
+	 * spectre_v2_select_mitigation(); specifically it wants to know about
+	 * spectre_v2=ibrs.
+	 */
+	retbleed_select_mitigation();
+	/*
+	 * spectre_v2_user_select_mitigation() relies on the state set by
+	 * retbleed_select_mitigation(); specifically the STIBP selection is
+	 * forced for UNRET.
+	 */
+	spectre_v2_user_select_mitigation();
 	ssb_select_mitigation();
 	l1tf_select_mitigation();
 	md_clear_select_mitigation();
@@ -152,31 +186,17 @@ void __init check_bugs(void)
 #endif
 }
 
+/*
+ * NOTE: For VMX, this function is not called in the vmexit path.
+ * It uses vmx_spec_ctrl_restore_host() instead.
+ */
 void
 x86_virt_spec_ctrl(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl, bool setguest)
 {
-	u64 msrval, guestval, hostval = x86_spec_ctrl_base;
+	u64 msrval, guestval = guest_spec_ctrl, hostval = spec_ctrl_current();
 	struct thread_info *ti = current_thread_info();
 
-	/* Is MSR_SPEC_CTRL implemented ? */
 	if (static_cpu_has(X86_FEATURE_MSR_SPEC_CTRL)) {
-		/*
-		 * Restrict guest_spec_ctrl to supported values. Clear the
-		 * modifiable bits in the host base value and or the
-		 * modifiable bits from the guest value.
-		 */
-		guestval = hostval & ~x86_spec_ctrl_mask;
-		guestval |= guest_spec_ctrl & x86_spec_ctrl_mask;
-
-		/* SSBD controlled in MSR_SPEC_CTRL */
-		if (static_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD) ||
-		    static_cpu_has(X86_FEATURE_AMD_SSBD))
-			hostval |= ssbd_tif_to_spec_ctrl(ti->flags);
-
-		/* Conditional STIBP enabled? */
-		if (static_branch_unlikely(&switch_to_cond_stibp))
-			hostval |= stibp_tif_to_spec_ctrl(ti->flags);
-
 		if (hostval != guestval) {
 			msrval = setguest ? guestval : hostval;
 			wrmsrl(MSR_IA32_SPEC_CTRL, msrval);
@@ -708,12 +728,180 @@ static int __init nospectre_v1_cmdline(char *str)
 }
 early_param("nospectre_v1", nospectre_v1_cmdline);
 
-#undef pr_fmt
-#define pr_fmt(fmt)     "Spectre V2 : " fmt
-
 static enum spectre_v2_mitigation spectre_v2_enabled __ro_after_init =
 	SPECTRE_V2_NONE;
 
+#undef pr_fmt
+#define pr_fmt(fmt)     "RETBleed: " fmt
+
+enum retbleed_mitigation {
+	RETBLEED_MITIGATION_NONE,
+	RETBLEED_MITIGATION_UNRET,
+	RETBLEED_MITIGATION_IBPB,
+	RETBLEED_MITIGATION_IBRS,
+	RETBLEED_MITIGATION_EIBRS,
+};
+
+enum retbleed_mitigation_cmd {
+	RETBLEED_CMD_OFF,
+	RETBLEED_CMD_AUTO,
+	RETBLEED_CMD_UNRET,
+	RETBLEED_CMD_IBPB,
+};
+
+const char * const retbleed_strings[] = {
+	[RETBLEED_MITIGATION_NONE]	= "Vulnerable",
+	[RETBLEED_MITIGATION_UNRET]	= "Mitigation: untrained return thunk",
+	[RETBLEED_MITIGATION_IBPB]	= "Mitigation: IBPB",
+	[RETBLEED_MITIGATION_IBRS]	= "Mitigation: IBRS",
+	[RETBLEED_MITIGATION_EIBRS]	= "Mitigation: Enhanced IBRS",
+};
+
+static enum retbleed_mitigation retbleed_mitigation __ro_after_init =
+	RETBLEED_MITIGATION_NONE;
+static enum retbleed_mitigation_cmd retbleed_cmd __ro_after_init =
+	RETBLEED_CMD_AUTO;
+
+static int __ro_after_init retbleed_nosmt = false;
+
+static int __init retbleed_parse_cmdline(char *str)
+{
+	if (!str)
+		return -EINVAL;
+
+	while (str) {
+		char *next = strchr(str, ',');
+		if (next) {
+			*next = 0;
+			next++;
+		}
+
+		if (!strcmp(str, "off")) {
+			retbleed_cmd = RETBLEED_CMD_OFF;
+		} else if (!strcmp(str, "auto")) {
+			retbleed_cmd = RETBLEED_CMD_AUTO;
+		} else if (!strcmp(str, "unret")) {
+			retbleed_cmd = RETBLEED_CMD_UNRET;
+		} else if (!strcmp(str, "ibpb")) {
+			retbleed_cmd = RETBLEED_CMD_IBPB;
+		} else if (!strcmp(str, "nosmt")) {
+			retbleed_nosmt = true;
+		} else {
+			pr_err("Ignoring unknown retbleed option (%s).", str);
+		}
+
+		str = next;
+	}
+
+	return 0;
+}
+early_param("retbleed", retbleed_parse_cmdline);
+
+#define RETBLEED_UNTRAIN_MSG "WARNING: BTB untrained return thunk mitigation is only effective on AMD/Hygon!\n"
+#define RETBLEED_INTEL_MSG "WARNING: Spectre v2 mitigation leaves CPU vulnerable to RETBleed attacks, data leaks possible!\n"
+
+static void __init retbleed_select_mitigation(void)
+{
+	bool mitigate_smt = false;
+
+	if (!boot_cpu_has_bug(X86_BUG_RETBLEED) || cpu_mitigations_off())
+		return;
+
+	switch (retbleed_cmd) {
+	case RETBLEED_CMD_OFF:
+		return;
+
+	case RETBLEED_CMD_UNRET:
+		if (IS_ENABLED(CONFIG_CPU_UNRET_ENTRY)) {
+			retbleed_mitigation = RETBLEED_MITIGATION_UNRET;
+		} else {
+			pr_err("WARNING: kernel not compiled with CPU_UNRET_ENTRY.\n");
+			goto do_cmd_auto;
+		}
+		break;
+
+	case RETBLEED_CMD_IBPB:
+		if (!boot_cpu_has(X86_FEATURE_IBPB)) {
+			pr_err("WARNING: CPU does not support IBPB.\n");
+			goto do_cmd_auto;
+		} else if (IS_ENABLED(CONFIG_CPU_IBPB_ENTRY)) {
+			retbleed_mitigation = RETBLEED_MITIGATION_IBPB;
+		} else {
+			pr_err("WARNING: kernel not compiled with CPU_IBPB_ENTRY.\n");
+			goto do_cmd_auto;
+		}
+		break;
+
+do_cmd_auto:
+	case RETBLEED_CMD_AUTO:
+	default:
+		if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
+		    boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) {
+			if (IS_ENABLED(CONFIG_CPU_UNRET_ENTRY))
+				retbleed_mitigation = RETBLEED_MITIGATION_UNRET;
+			else if (IS_ENABLED(CONFIG_CPU_IBPB_ENTRY) && boot_cpu_has(X86_FEATURE_IBPB))
+				retbleed_mitigation = RETBLEED_MITIGATION_IBPB;
+		}
+
+		/*
+		 * The Intel mitigation (IBRS or eIBRS) was already selected in
+		 * spectre_v2_select_mitigation().  'retbleed_mitigation' will
+		 * be set accordingly below.
+		 */
+
+		break;
+	}
+
+	switch (retbleed_mitigation) {
+	case RETBLEED_MITIGATION_UNRET:
+		setup_force_cpu_cap(X86_FEATURE_RETHUNK);
+		setup_force_cpu_cap(X86_FEATURE_UNRET);
+
+		if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
+		    boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
+			pr_err(RETBLEED_UNTRAIN_MSG);
+
+		mitigate_smt = true;
+		break;
+
+	case RETBLEED_MITIGATION_IBPB:
+		setup_force_cpu_cap(X86_FEATURE_ENTRY_IBPB);
+		mitigate_smt = true;
+		break;
+
+	default:
+		break;
+	}
+
+	if (mitigate_smt && !boot_cpu_has(X86_FEATURE_STIBP) &&
+	    (retbleed_nosmt || cpu_mitigations_auto_nosmt()))
+		cpu_smt_disable(false);
+
+	/*
+	 * Let IBRS trump all on Intel without affecting the effects of the
+	 * retbleed= cmdline option.
+	 */
+	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) {
+		switch (spectre_v2_enabled) {
+		case SPECTRE_V2_IBRS:
+			retbleed_mitigation = RETBLEED_MITIGATION_IBRS;
+			break;
+		case SPECTRE_V2_EIBRS:
+		case SPECTRE_V2_EIBRS_RETPOLINE:
+		case SPECTRE_V2_EIBRS_LFENCE:
+			retbleed_mitigation = RETBLEED_MITIGATION_EIBRS;
+			break;
+		default:
+			pr_err(RETBLEED_INTEL_MSG);
+		}
+	}
+
+	pr_info("%s\n", retbleed_strings[retbleed_mitigation]);
+}
+
+#undef pr_fmt
+#define pr_fmt(fmt)     "Spectre V2 : " fmt
+
 static enum spectre_v2_user_mitigation spectre_v2_user_stibp __ro_after_init =
 	SPECTRE_V2_USER_NONE;
 static enum spectre_v2_user_mitigation spectre_v2_user_ibpb __ro_after_init =
@@ -784,6 +972,7 @@ enum spectre_v2_mitigation_cmd {
 	SPECTRE_V2_CMD_EIBRS,
 	SPECTRE_V2_CMD_EIBRS_RETPOLINE,
 	SPECTRE_V2_CMD_EIBRS_LFENCE,
+	SPECTRE_V2_CMD_IBRS,
 };
 
 enum spectre_v2_user_cmd {
@@ -824,13 +1013,15 @@ static void __init spec_v2_user_print_cond(const char *reason, bool secure)
 		pr_info("spectre_v2_user=%s forced on command line.\n", reason);
 }
 
+static __ro_after_init enum spectre_v2_mitigation_cmd spectre_v2_cmd;
+
 static enum spectre_v2_user_cmd __init
-spectre_v2_parse_user_cmdline(enum spectre_v2_mitigation_cmd v2_cmd)
+spectre_v2_parse_user_cmdline(void)
 {
 	char arg[20];
 	int ret, i;
 
-	switch (v2_cmd) {
+	switch (spectre_v2_cmd) {
 	case SPECTRE_V2_CMD_NONE:
 		return SPECTRE_V2_USER_CMD_NONE;
 	case SPECTRE_V2_CMD_FORCE:
@@ -856,15 +1047,16 @@ spectre_v2_parse_user_cmdline(enum spectre_v2_mitigation_cmd v2_cmd)
 	return SPECTRE_V2_USER_CMD_AUTO;
 }
 
-static inline bool spectre_v2_in_eibrs_mode(enum spectre_v2_mitigation mode)
+static inline bool spectre_v2_in_ibrs_mode(enum spectre_v2_mitigation mode)
 {
-	return (mode == SPECTRE_V2_EIBRS ||
+	return mode == SPECTRE_V2_IBRS ||
-		mode == SPECTRE_V2_EIBRS_RETPOLINE ||
+	       mode == SPECTRE_V2_EIBRS ||
-		mode == SPECTRE_V2_EIBRS_LFENCE);
+	       mode == SPECTRE_V2_EIBRS_RETPOLINE ||
+	       mode == SPECTRE_V2_EIBRS_LFENCE;
 }
 
 static void __init
-spectre_v2_user_select_mitigation(enum spectre_v2_mitigation_cmd v2_cmd)
+spectre_v2_user_select_mitigation(void)
 {
 	enum spectre_v2_user_mitigation mode = SPECTRE_V2_USER_NONE;
 	bool smt_possible = IS_ENABLED(CONFIG_SMP);
@@ -877,7 +1069,7 @@ spectre_v2_user_select_mitigation(enum spectre_v2_mitigation_cmd v2_cmd)
 	    cpu_smt_control == CPU_SMT_NOT_SUPPORTED)
 		smt_possible = false;
 
-	cmd = spectre_v2_parse_user_cmdline(v2_cmd);
+	cmd = spectre_v2_parse_user_cmdline();
 	switch (cmd) {
 	case SPECTRE_V2_USER_CMD_NONE:
 		goto set_mode;
@@ -925,12 +1117,12 @@ spectre_v2_user_select_mitigation(enum spectre_v2_mitigation_cmd v2_cmd)
 	}
 
 	/*
-	 * If no STIBP, enhanced IBRS is enabled or SMT impossible, STIBP is not
+	 * If no STIBP, IBRS or enhanced IBRS is enabled, or SMT impossible,
-	 * required.
+	 * STIBP is not required.
 	 */
 	if (!boot_cpu_has(X86_FEATURE_STIBP) ||
 	    !smt_possible ||
-	    spectre_v2_in_eibrs_mode(spectre_v2_enabled))
+	    spectre_v2_in_ibrs_mode(spectre_v2_enabled))
 		return;
 
 	/*
@@ -942,6 +1134,13 @@ spectre_v2_user_select_mitigation(enum spectre_v2_mitigation_cmd v2_cmd)
 	    boot_cpu_has(X86_FEATURE_AMD_STIBP_ALWAYS_ON))
 		mode = SPECTRE_V2_USER_STRICT_PREFERRED;
 
+	if (retbleed_mitigation == RETBLEED_MITIGATION_UNRET) {
+		if (mode != SPECTRE_V2_USER_STRICT &&
+		    mode != SPECTRE_V2_USER_STRICT_PREFERRED)
+			pr_info("Selecting STIBP always-on mode to complement retbleed mitigation\n");
+		mode = SPECTRE_V2_USER_STRICT_PREFERRED;
+	}
+
 	spectre_v2_user_stibp = mode;
 
 set_mode:
@@ -955,6 +1154,7 @@ static const char * const spectre_v2_strings[] = {
 	[SPECTRE_V2_EIBRS]			= "Mitigation: Enhanced IBRS",
 	[SPECTRE_V2_EIBRS_LFENCE]		= "Mitigation: Enhanced IBRS + LFENCE",
 	[SPECTRE_V2_EIBRS_RETPOLINE]		= "Mitigation: Enhanced IBRS + Retpolines",
+	[SPECTRE_V2_IBRS]			= "Mitigation: IBRS",
 };
 
 static const struct {
@@ -972,6 +1172,7 @@ static const struct {
 	{ "eibrs,lfence",	SPECTRE_V2_CMD_EIBRS_LFENCE,	  false },
 	{ "eibrs,retpoline",	SPECTRE_V2_CMD_EIBRS_RETPOLINE,	  false },
 	{ "auto",		SPECTRE_V2_CMD_AUTO,		  false },
+	{ "ibrs",		SPECTRE_V2_CMD_IBRS,              false },
 };
 
 static void __init spec_v2_print_cond(const char *reason, bool secure)
@@ -1034,6 +1235,30 @@ static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void)
 		return SPECTRE_V2_CMD_AUTO;
 	}
 
+	if (cmd == SPECTRE_V2_CMD_IBRS && !IS_ENABLED(CONFIG_CPU_IBRS_ENTRY)) {
+		pr_err("%s selected but not compiled in. Switching to AUTO select\n",
+		       mitigation_options[i].option);
+		return SPECTRE_V2_CMD_AUTO;
+	}
+
+	if (cmd == SPECTRE_V2_CMD_IBRS && boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) {
+		pr_err("%s selected but not Intel CPU. Switching to AUTO select\n",
+		       mitigation_options[i].option);
+		return SPECTRE_V2_CMD_AUTO;
+	}
+
+	if (cmd == SPECTRE_V2_CMD_IBRS && !boot_cpu_has(X86_FEATURE_IBRS)) {
+		pr_err("%s selected but CPU doesn't have IBRS. Switching to AUTO select\n",
+		       mitigation_options[i].option);
+		return SPECTRE_V2_CMD_AUTO;
+	}
+
+	if (cmd == SPECTRE_V2_CMD_IBRS && boot_cpu_has(X86_FEATURE_XENPV)) {
+		pr_err("%s selected but running as XenPV guest. Switching to AUTO select\n",
+		       mitigation_options[i].option);
+		return SPECTRE_V2_CMD_AUTO;
+	}
+
 	spec_v2_print_cond(mitigation_options[i].option,
 			   mitigation_options[i].secure);
 	return cmd;
@@ -1049,6 +1274,22 @@ static enum spectre_v2_mitigation __init spectre_v2_select_retpoline(void)
 	return SPECTRE_V2_RETPOLINE;
 }
 
+/* Disable in-kernel use of non-RSB RET predictors */
+static void __init spec_ctrl_disable_kernel_rrsba(void)
+{
+	u64 ia32_cap;
+
+	if (!boot_cpu_has(X86_FEATURE_RRSBA_CTRL))
+		return;
+
+	ia32_cap = x86_read_arch_cap_msr();
+
+	if (ia32_cap & ARCH_CAP_RRSBA) {
+		x86_spec_ctrl_base |= SPEC_CTRL_RRSBA_DIS_S;
+		write_spec_ctrl_current(x86_spec_ctrl_base, true);
+	}
+}
+
 static void __init spectre_v2_select_mitigation(void)
 {
 	enum spectre_v2_mitigation_cmd cmd = spectre_v2_parse_cmdline();
@@ -1073,6 +1314,15 @@ static void __init spectre_v2_select_mitigation(void)
 			break;
 		}
 
+		if (IS_ENABLED(CONFIG_CPU_IBRS_ENTRY) &&
+		    boot_cpu_has_bug(X86_BUG_RETBLEED) &&
+		    retbleed_cmd != RETBLEED_CMD_OFF &&
+		    boot_cpu_has(X86_FEATURE_IBRS) &&
+		    boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) {
+			mode = SPECTRE_V2_IBRS;
+			break;
+		}
+
 		mode = spectre_v2_select_retpoline();
 		break;
 
@@ -1089,6 +1339,10 @@ static void __init spectre_v2_select_mitigation(void)
 		mode = spectre_v2_select_retpoline();
 		break;
 
+	case SPECTRE_V2_CMD_IBRS:
+		mode = SPECTRE_V2_IBRS;
+		break;
+
 	case SPECTRE_V2_CMD_EIBRS:
 		mode = SPECTRE_V2_EIBRS;
 		break;
@@ -1105,10 +1359,9 @@ static void __init spectre_v2_select_mitigation(void)
 	if (mode == SPECTRE_V2_EIBRS && unprivileged_ebpf_enabled())
 		pr_err(SPECTRE_V2_EIBRS_EBPF_MSG);
 
-	if (spectre_v2_in_eibrs_mode(mode)) {
+	if (spectre_v2_in_ibrs_mode(mode)) {
-		/* Force it so VMEXIT will restore correctly */
 		x86_spec_ctrl_base |= SPEC_CTRL_IBRS;
-		wrmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
+		write_spec_ctrl_current(x86_spec_ctrl_base, true);
 	}
 
 	switch (mode) {
@@ -1116,6 +1369,10 @@ static void __init spectre_v2_select_mitigation(void)
 	case SPECTRE_V2_EIBRS:
 		break;
 
+	case SPECTRE_V2_IBRS:
+		setup_force_cpu_cap(X86_FEATURE_KERNEL_IBRS);
+		break;
+
 	case SPECTRE_V2_LFENCE:
 	case SPECTRE_V2_EIBRS_LFENCE:
 		setup_force_cpu_cap(X86_FEATURE_RETPOLINE_LFENCE);
@@ -1127,43 +1384,107 @@ static void __init spectre_v2_select_mitigation(void)
 		break;
 	}
 
+	/*
+	 * Disable alternate RSB predictions in kernel when indirect CALLs and
+	 * JMPs gets protection against BHI and Intramode-BTI, but RET
+	 * prediction from a non-RSB predictor is still a risk.
+	 */
+	if (mode == SPECTRE_V2_EIBRS_LFENCE ||
+	    mode == SPECTRE_V2_EIBRS_RETPOLINE ||
+	    mode == SPECTRE_V2_RETPOLINE)
+		spec_ctrl_disable_kernel_rrsba();
+
 	spectre_v2_enabled = mode;
 	pr_info("%s\n", spectre_v2_strings[mode]);
 
 	/*
-	 * If spectre v2 protection has been enabled, unconditionally fill
+	 * If Spectre v2 protection has been enabled, fill the RSB during a
-	 * RSB during a context switch; this protects against two independent
+	 * context switch.  In general there are two types of RSB attacks
-	 * issues:
+	 * across context switches, for which the CALLs/RETs may be unbalanced.
 	 *
-	 *	- RSB underflow (and switch to BTB) on Skylake+
+	 * 1) RSB underflow
-	 *	- SpectreRSB variant of spectre v2 on X86_BUG_SPECTRE_V2 CPUs
+	 *
+	 *    Some Intel parts have "bottomless RSB".  When the RSB is empty,
+	 *    speculated return targets may come from the branch predictor,
+	 *    which could have a user-poisoned BTB or BHB entry.
+	 *
+	 *    AMD has it even worse: *all* returns are speculated from the BTB,
+	 *    regardless of the state of the RSB.
+	 *
+	 *    When IBRS or eIBRS is enabled, the "user -> kernel" attack
+	 *    scenario is mitigated by the IBRS branch prediction isolation
+	 *    properties, so the RSB buffer filling wouldn't be necessary to
+	 *    protect against this type of attack.
+	 *
+	 *    The "user -> user" attack scenario is mitigated by RSB filling.
+	 *
+	 * 2) Poisoned RSB entry
+	 *
+	 *    If the 'next' in-kernel return stack is shorter than 'prev',
+	 *    'next' could be tricked into speculating with a user-poisoned RSB
+	 *    entry.
+	 *
+	 *    The "user -> kernel" attack scenario is mitigated by SMEP and
+	 *    eIBRS.
+	 *
+	 *    The "user -> user" scenario, also known as SpectreBHB, requires
+	 *    RSB clearing.
+	 *
+	 * So to mitigate all cases, unconditionally fill RSB on context
+	 * switches.
+	 *
+	 * FIXME: Is this pointless for retbleed-affected AMD?
 	 */
 	setup_force_cpu_cap(X86_FEATURE_RSB_CTXSW);
 	pr_info("Spectre v2 / SpectreRSB mitigation: Filling RSB on context switch\n");
 
 	/*
-	 * Retpoline means the kernel is safe because it has no indirect
+	 * Similar to context switches, there are two types of RSB attacks
-	 * branches. Enhanced IBRS protects firmware too, so, enable restricted
+	 * after vmexit:
-	 * speculation around firmware calls only when Enhanced IBRS isn't
+	 *
-	 * supported.
+	 * 1) RSB underflow
+	 *
+	 * 2) Poisoned RSB entry
+	 *
+	 * When retpoline is enabled, both are mitigated by filling/clearing
+	 * the RSB.
+	 *
+	 * When IBRS is enabled, while #1 would be mitigated by the IBRS branch
+	 * prediction isolation protections, RSB still needs to be cleared
+	 * because of #2.  Note that SMEP provides no protection here, unlike
+	 * user-space-poisoned RSB entries.
+	 *
+	 * eIBRS, on the other hand, has RSB-poisoning protections, so it
+	 * doesn't need RSB clearing after vmexit.
+	 */
+	if (boot_cpu_has(X86_FEATURE_RETPOLINE) ||
+	    boot_cpu_has(X86_FEATURE_KERNEL_IBRS))
+		setup_force_cpu_cap(X86_FEATURE_RSB_VMEXIT);
+
+	/*
+	 * Retpoline protects the kernel, but doesn't protect firmware.  IBRS
+	 * and Enhanced IBRS protect firmware too, so enable IBRS around
+	 * firmware calls only when IBRS / Enhanced IBRS aren't otherwise
+	 * enabled.
 	 *
 	 * Use "mode" to check Enhanced IBRS instead of boot_cpu_has(), because
 	 * the user might select retpoline on the kernel command line and if
 	 * the CPU supports Enhanced IBRS, kernel might un-intentionally not
 	 * enable IBRS around firmware calls.
 	 */
-	if (boot_cpu_has(X86_FEATURE_IBRS) && !spectre_v2_in_eibrs_mode(mode)) {
+	if (boot_cpu_has(X86_FEATURE_IBRS) && !spectre_v2_in_ibrs_mode(mode)) {
 		setup_force_cpu_cap(X86_FEATURE_USE_IBRS_FW);
 		pr_info("Enabling Restricted Speculation for firmware calls\n");
 	}
 
 	/* Set up IBPB and STIBP depending on the general spectre V2 command */
-	spectre_v2_user_select_mitigation(cmd);
+	spectre_v2_cmd = cmd;
 }
 
 static void update_stibp_msr(void * __unused)
 {
-	wrmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
+	u64 val = spec_ctrl_current() | (x86_spec_ctrl_base & SPEC_CTRL_STIBP);
+	write_spec_ctrl_current(val, true);
 }
 
 /* Update x86_spec_ctrl_base in case SMT state changed. */
@@ -1379,16 +1700,6 @@ static enum ssb_mitigation __init __ssb_select_mitigation(void)
 		break;
 	}
 
-	/*
-	 * If SSBD is controlled by the SPEC_CTRL MSR, then set the proper
-	 * bit in the mask to allow guests to use the mitigation even in the
-	 * case where the host does not enable it.
-	 */
-	if (static_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD) ||
-	    static_cpu_has(X86_FEATURE_AMD_SSBD)) {
-		x86_spec_ctrl_mask |= SPEC_CTRL_SSBD;
-	}
-
 	/*
 	 * We have three CPU feature flags that are in play here:
 	 *  - X86_BUG_SPEC_STORE_BYPASS - CPU is susceptible.
@@ -1406,7 +1717,7 @@ static enum ssb_mitigation __init __ssb_select_mitigation(void)
 			x86_amd_ssb_disable();
 		} else {
 			x86_spec_ctrl_base |= SPEC_CTRL_SSBD;
-			wrmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
+			write_spec_ctrl_current(x86_spec_ctrl_base, true);
 		}
 	}
 
@@ -1624,7 +1935,7 @@ int arch_prctl_spec_ctrl_get(struct task_struct *task, unsigned long which)
 void x86_spec_ctrl_setup_ap(void)
 {
 	if (boot_cpu_has(X86_FEATURE_MSR_SPEC_CTRL))
-		wrmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
+		write_spec_ctrl_current(x86_spec_ctrl_base, true);
 
 	if (ssb_mode == SPEC_STORE_BYPASS_DISABLE)
 		x86_amd_ssb_disable();
@@ -1861,7 +2172,7 @@ static ssize_t mmio_stale_data_show_state(char *buf)
 
 static char *stibp_state(void)
 {
-	if (spectre_v2_in_eibrs_mode(spectre_v2_enabled))
+	if (spectre_v2_in_ibrs_mode(spectre_v2_enabled))
 		return "";
 
 	switch (spectre_v2_user_stibp) {
@@ -1917,6 +2228,24 @@ static ssize_t srbds_show_state(char *buf)
 	return sprintf(buf, "%s\n", srbds_strings[srbds_mitigation]);
 }
 
+static ssize_t retbleed_show_state(char *buf)
+{
+	if (retbleed_mitigation == RETBLEED_MITIGATION_UNRET) {
+	    if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
+		boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
+		    return sprintf(buf, "Vulnerable: untrained return thunk on non-Zen uarch\n");
+
+	    return sprintf(buf, "%s; SMT %s\n",
+			   retbleed_strings[retbleed_mitigation],
+			   !sched_smt_active() ? "disabled" :
+			   spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT ||
+			   spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED ?
+			   "enabled with STIBP protection" : "vulnerable");
+	}
+
+	return sprintf(buf, "%s\n", retbleed_strings[retbleed_mitigation]);
+}
+
 static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr,
 			       char *buf, unsigned int bug)
 {
@@ -1962,6 +2291,9 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr
 	case X86_BUG_MMIO_STALE_DATA:
 		return mmio_stale_data_show_state(buf);
 
+	case X86_BUG_RETBLEED:
+		return retbleed_show_state(buf);
+
 	default:
 		break;
 	}
@@ -2018,4 +2350,9 @@ ssize_t cpu_show_mmio_stale_data(struct device *dev, struct device_attribute *at
 {
 	return cpu_show_common(dev, attr, buf, X86_BUG_MMIO_STALE_DATA);
 }
+
+ssize_t cpu_show_retbleed(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	return cpu_show_common(dev, attr, buf, X86_BUG_RETBLEED);
+}
 #endif

arch/x86/kernel/cpu/common.c

@@ -1092,48 +1092,60 @@ static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = {
 	{}
 };
 
+#define VULNBL(vendor, family, model, blacklist)	\
+	X86_MATCH_VENDOR_FAM_MODEL(vendor, family, model, blacklist)
+
 #define VULNBL_INTEL_STEPPINGS(model, steppings, issues)		   \
 	X86_MATCH_VENDOR_FAM_MODEL_STEPPINGS_FEATURE(INTEL, 6,		   \
 					    INTEL_FAM6_##model, steppings, \
 					    X86_FEATURE_ANY, issues)
 
+#define VULNBL_AMD(family, blacklist)		\
+	VULNBL(AMD, family, X86_MODEL_ANY, blacklist)
+
+#define VULNBL_HYGON(family, blacklist)		\
+	VULNBL(HYGON, family, X86_MODEL_ANY, blacklist)
+
 #define SRBDS		BIT(0)
 /* CPU is affected by X86_BUG_MMIO_STALE_DATA */
 #define MMIO		BIT(1)
 /* CPU is affected by Shared Buffers Data Sampling (SBDS), a variant of X86_BUG_MMIO_STALE_DATA */
 #define MMIO_SBDS	BIT(2)
+/* CPU is affected by RETbleed, speculating where you would not expect it */
+#define RETBLEED	BIT(3)
 
 static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = {
 	VULNBL_INTEL_STEPPINGS(IVYBRIDGE,	X86_STEPPING_ANY,		SRBDS),
 	VULNBL_INTEL_STEPPINGS(HASWELL,		X86_STEPPING_ANY,		SRBDS),
 	VULNBL_INTEL_STEPPINGS(HASWELL_L,	X86_STEPPING_ANY,		SRBDS),
 	VULNBL_INTEL_STEPPINGS(HASWELL_G,	X86_STEPPING_ANY,		SRBDS),
-	VULNBL_INTEL_STEPPINGS(HASWELL_X,	BIT(2) | BIT(4),		MMIO),
+	VULNBL_INTEL_STEPPINGS(HASWELL_X,	X86_STEPPING_ANY,		MMIO),
-	VULNBL_INTEL_STEPPINGS(BROADWELL_D,	X86_STEPPINGS(0x3, 0x5),	MMIO),
+	VULNBL_INTEL_STEPPINGS(BROADWELL_D,	X86_STEPPING_ANY,		MMIO),
 	VULNBL_INTEL_STEPPINGS(BROADWELL_G,	X86_STEPPING_ANY,		SRBDS),
 	VULNBL_INTEL_STEPPINGS(BROADWELL_X,	X86_STEPPING_ANY,		MMIO),
 	VULNBL_INTEL_STEPPINGS(BROADWELL,	X86_STEPPING_ANY,		SRBDS),
-	VULNBL_INTEL_STEPPINGS(SKYLAKE_L,	X86_STEPPINGS(0x3, 0x3),	SRBDS | MMIO),
+	VULNBL_INTEL_STEPPINGS(SKYLAKE_L,	X86_STEPPING_ANY,		SRBDS | MMIO | RETBLEED),
-	VULNBL_INTEL_STEPPINGS(SKYLAKE_L,	X86_STEPPING_ANY,		SRBDS),
+	VULNBL_INTEL_STEPPINGS(SKYLAKE_X,	X86_STEPPING_ANY,		MMIO | RETBLEED),
-	VULNBL_INTEL_STEPPINGS(SKYLAKE_X,	BIT(3) | BIT(4) | BIT(6) |
+	VULNBL_INTEL_STEPPINGS(SKYLAKE,		X86_STEPPING_ANY,		SRBDS | MMIO | RETBLEED),
-						BIT(7) | BIT(0xB),              MMIO),
+	VULNBL_INTEL_STEPPINGS(KABYLAKE_L,	X86_STEPPING_ANY,		SRBDS | MMIO | RETBLEED),
-	VULNBL_INTEL_STEPPINGS(SKYLAKE,		X86_STEPPINGS(0x3, 0x3),	SRBDS | MMIO),
+	VULNBL_INTEL_STEPPINGS(KABYLAKE,	X86_STEPPING_ANY,		SRBDS | MMIO | RETBLEED),
-	VULNBL_INTEL_STEPPINGS(SKYLAKE,		X86_STEPPING_ANY,		SRBDS),
+	VULNBL_INTEL_STEPPINGS(CANNONLAKE_L,	X86_STEPPING_ANY,		RETBLEED),
-	VULNBL_INTEL_STEPPINGS(KABYLAKE_L,	X86_STEPPINGS(0x9, 0xC),	SRBDS | MMIO),
+	VULNBL_INTEL_STEPPINGS(ICELAKE_L,	X86_STEPPING_ANY,		MMIO | MMIO_SBDS | RETBLEED),
-	VULNBL_INTEL_STEPPINGS(KABYLAKE_L,	X86_STEPPINGS(0x0, 0x8),	SRBDS),
+	VULNBL_INTEL_STEPPINGS(ICELAKE_D,	X86_STEPPING_ANY,		MMIO),
-	VULNBL_INTEL_STEPPINGS(KABYLAKE,	X86_STEPPINGS(0x9, 0xD),	SRBDS | MMIO),
+	VULNBL_INTEL_STEPPINGS(ICELAKE_X,	X86_STEPPING_ANY,		MMIO),
-	VULNBL_INTEL_STEPPINGS(KABYLAKE,	X86_STEPPINGS(0x0, 0x8),	SRBDS),
+	VULNBL_INTEL_STEPPINGS(COMETLAKE,	X86_STEPPING_ANY,		MMIO | MMIO_SBDS | RETBLEED),
-	VULNBL_INTEL_STEPPINGS(ICELAKE_L,	X86_STEPPINGS(0x5, 0x5),	MMIO | MMIO_SBDS),
+	VULNBL_INTEL_STEPPINGS(COMETLAKE_L,	X86_STEPPINGS(0x0, 0x0),	MMIO | RETBLEED),
-	VULNBL_INTEL_STEPPINGS(ICELAKE_D,	X86_STEPPINGS(0x1, 0x1),	MMIO),
+	VULNBL_INTEL_STEPPINGS(COMETLAKE_L,	X86_STEPPING_ANY,		MMIO | MMIO_SBDS | RETBLEED),
-	VULNBL_INTEL_STEPPINGS(ICELAKE_X,	X86_STEPPINGS(0x4, 0x6),	MMIO),
+	VULNBL_INTEL_STEPPINGS(LAKEFIELD,	X86_STEPPING_ANY,		MMIO | MMIO_SBDS | RETBLEED),
-	VULNBL_INTEL_STEPPINGS(COMETLAKE,	BIT(2) | BIT(3) | BIT(5),	MMIO | MMIO_SBDS),
+	VULNBL_INTEL_STEPPINGS(ROCKETLAKE,	X86_STEPPING_ANY,		MMIO | RETBLEED),
-	VULNBL_INTEL_STEPPINGS(COMETLAKE_L,	X86_STEPPINGS(0x1, 0x1),	MMIO | MMIO_SBDS),
+	VULNBL_INTEL_STEPPINGS(ATOM_TREMONT,	X86_STEPPING_ANY,		MMIO | MMIO_SBDS),
-	VULNBL_INTEL_STEPPINGS(COMETLAKE_L,	X86_STEPPINGS(0x0, 0x0),	MMIO),
-	VULNBL_INTEL_STEPPINGS(LAKEFIELD,	X86_STEPPINGS(0x1, 0x1),	MMIO | MMIO_SBDS),
-	VULNBL_INTEL_STEPPINGS(ROCKETLAKE,	X86_STEPPINGS(0x1, 0x1),	MMIO),
-	VULNBL_INTEL_STEPPINGS(ATOM_TREMONT,	X86_STEPPINGS(0x1, 0x1),	MMIO | MMIO_SBDS),
 	VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_D,	X86_STEPPING_ANY,		MMIO),
-	VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_L,	X86_STEPPINGS(0x0, 0x0),	MMIO | MMIO_SBDS),
+	VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_L,	X86_STEPPING_ANY,		MMIO | MMIO_SBDS),
+
+	VULNBL_AMD(0x15, RETBLEED),
+	VULNBL_AMD(0x16, RETBLEED),
+	VULNBL_AMD(0x17, RETBLEED),
+	VULNBL_HYGON(0x18, RETBLEED),
 	{}
 };
 
@@ -1235,6 +1247,11 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 	    !arch_cap_mmio_immune(ia32_cap))
 		setup_force_cpu_bug(X86_BUG_MMIO_STALE_DATA);
 
+	if (!cpu_has(c, X86_FEATURE_BTC_NO)) {
+		if (cpu_matches(cpu_vuln_blacklist, RETBLEED) || (ia32_cap & ARCH_CAP_RSBA))
+			setup_force_cpu_bug(X86_BUG_RETBLEED);
+	}
+
 	if (cpu_matches(cpu_vuln_whitelist, NO_MELTDOWN))
 		return;
 

arch/x86/kernel/cpu/cpu.h

@@ -60,6 +60,8 @@ extern void tsx_disable(void);
 static inline void tsx_init(void) { }
 #endif /* CONFIG_CPU_SUP_INTEL */
 
+extern void init_spectral_chicken(struct cpuinfo_x86 *c);
+
 extern void get_cpu_cap(struct cpuinfo_x86 *c);
 extern void get_cpu_address_sizes(struct cpuinfo_x86 *c);
 extern void cpu_detect_cache_sizes(struct cpuinfo_x86 *c);

arch/x86/kernel/cpu/hygon.c

@@ -318,6 +318,12 @@ static void init_hygon(struct cpuinfo_x86 *c)
 	/* get apicid instead of initial apic id from cpuid */
 	c->apicid = hard_smp_processor_id();
 
+	/*
+	 * XXX someone from Hygon needs to confirm this DTRT
+	 *
+	init_spectral_chicken(c);
+	 */
+
 	set_cpu_cap(c, X86_FEATURE_ZEN);
 	set_cpu_cap(c, X86_FEATURE_CPB);
 

arch/x86/kernel/cpu/scattered.c

@@ -26,6 +26,7 @@ struct cpuid_bit {
 static const struct cpuid_bit cpuid_bits[] = {
 	{ X86_FEATURE_APERFMPERF,       CPUID_ECX,  0, 0x00000006, 0 },
 	{ X86_FEATURE_EPB,		CPUID_ECX,  3, 0x00000006, 0 },
+	{ X86_FEATURE_RRSBA_CTRL,	CPUID_EDX,  2, 0x00000007, 2 },
 	{ X86_FEATURE_CQM_LLC,		CPUID_EDX,  1, 0x0000000f, 0 },
 	{ X86_FEATURE_CQM_OCCUP_LLC,	CPUID_EDX,  0, 0x0000000f, 1 },
 	{ X86_FEATURE_CQM_MBM_TOTAL,	CPUID_EDX,  1, 0x0000000f, 1 },

arch/x86/kernel/ftrace.c

@@ -308,7 +308,7 @@ union ftrace_op_code_union {
 	} __attribute__((packed));
 };
 
-#define RET_SIZE		1
+#define RET_SIZE		(IS_ENABLED(CONFIG_RETPOLINE) ? 5 : 1 + IS_ENABLED(CONFIG_SLS))
 
 static unsigned long
 create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
@@ -367,7 +367,10 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
 
 	/* The trampoline ends with ret(q) */
 	retq = (unsigned long)ftrace_stub;
-	ret = copy_from_kernel_nofault(ip, (void *)retq, RET_SIZE);
+	if (cpu_feature_enabled(X86_FEATURE_RETHUNK))
+		memcpy(ip, text_gen_insn(JMP32_INSN_OPCODE, ip, &__x86_return_thunk), JMP32_INSN_SIZE);
+	else
+		ret = copy_from_kernel_nofault(ip, (void *)retq, RET_SIZE);
 	if (WARN_ON(ret < 0))
 		goto fail;
 

arch/x86/kernel/ftrace_32.S

@@ -19,7 +19,7 @@
 #endif
 
 SYM_FUNC_START(__fentry__)
-	ret
+	RET
 SYM_FUNC_END(__fentry__)
 EXPORT_SYMBOL(__fentry__)
 
@@ -84,7 +84,7 @@ ftrace_graph_call:
 
 /* This is weak to keep gas from relaxing the jumps */
 SYM_INNER_LABEL_ALIGN(ftrace_stub, SYM_L_WEAK)
-	ret
+	RET
 SYM_CODE_END(ftrace_caller)
 
 SYM_CODE_START(ftrace_regs_caller)
@@ -177,7 +177,7 @@ SYM_CODE_START(ftrace_graph_caller)
 	popl	%edx
 	popl	%ecx
 	popl	%eax
-	ret
+	RET
 SYM_CODE_END(ftrace_graph_caller)
 
 .globl return_to_handler

arch/x86/kernel/ftrace_64.S

@@ -132,7 +132,7 @@
 #ifdef CONFIG_DYNAMIC_FTRACE
 
 SYM_FUNC_START(__fentry__)
-	retq
+	RET
 SYM_FUNC_END(__fentry__)
 EXPORT_SYMBOL(__fentry__)
 
@@ -170,10 +170,11 @@ SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL)
 
 /*
  * This is weak to keep gas from relaxing the jumps.
- * It is also used to copy the retq for trampolines.
+ * It is also used to copy the RET for trampolines.
  */
 SYM_INNER_LABEL_ALIGN(ftrace_stub, SYM_L_WEAK)
-	retq
+	UNWIND_HINT_FUNC
+	RET
 SYM_FUNC_END(ftrace_epilogue)
 
 SYM_FUNC_START(ftrace_regs_caller)
@@ -265,7 +266,7 @@ SYM_INNER_LABEL(ftrace_regs_caller_end, SYM_L_GLOBAL)
 	restore_mcount_regs 8
 	/* Restore flags */
 	popfq
-	UNWIND_HINT_RET_OFFSET
+	UNWIND_HINT_FUNC
 	jmp	ftrace_epilogue
 
 SYM_FUNC_END(ftrace_regs_caller)
@@ -287,7 +288,7 @@ fgraph_trace:
 #endif
 
 SYM_INNER_LABEL(ftrace_stub, SYM_L_GLOBAL)
-	retq
+	RET
 
 trace:
 	/* save_mcount_regs fills in first two parameters */
@@ -319,7 +320,7 @@ SYM_FUNC_START(ftrace_graph_caller)
 
 	restore_mcount_regs
 
-	retq
+	RET
 SYM_FUNC_END(ftrace_graph_caller)
 
 SYM_CODE_START(return_to_handler)

arch/x86/kernel/head_32.S

@@ -23,6 +23,7 @@
 #include <asm/cpufeatures.h>
 #include <asm/percpu.h>
 #include <asm/nops.h>
+#include <asm/nospec-branch.h>
 #include <asm/bootparam.h>
 #include <asm/export.h>
 #include <asm/pgtable_32.h>
@@ -354,7 +355,7 @@ setup_once:
 #endif
 
 	andl $0,setup_once_ref	/* Once is enough, thanks */
-	ret
+	RET
 
 SYM_FUNC_START(early_idt_handler_array)
 	# 36(%esp) %eflags

arch/x86/kernel/head_64.S

@@ -321,6 +321,8 @@ SYM_CODE_END(start_cpu0)
 SYM_CODE_START_NOALIGN(vc_boot_ghcb)
 	UNWIND_HINT_IRET_REGS offset=8
 
+	ANNOTATE_UNRET_END
+
 	/* Build pt_regs */
 	PUSH_AND_CLEAR_REGS
 
@@ -378,6 +380,7 @@ SYM_CODE_START(early_idt_handler_array)
 SYM_CODE_END(early_idt_handler_array)
 
 SYM_CODE_START_LOCAL(early_idt_handler_common)
+	ANNOTATE_UNRET_END
 	/*
 	 * The stack is the hardware frame, an error code or zero, and the
 	 * vector number.
@@ -424,6 +427,8 @@ SYM_CODE_END(early_idt_handler_common)
 SYM_CODE_START_NOALIGN(vc_no_ghcb)
 	UNWIND_HINT_IRET_REGS offset=8
 
+	ANNOTATE_UNRET_END
+
 	/* Build pt_regs */
 	PUSH_AND_CLEAR_REGS
 

arch/x86/kernel/irqflags.S

@@ -10,7 +10,7 @@
 SYM_FUNC_START(native_save_fl)
 	pushf
 	pop %_ASM_AX
-	ret
+	RET
 SYM_FUNC_END(native_save_fl)
 EXPORT_SYMBOL(native_save_fl)
 
@@ -21,6 +21,6 @@ EXPORT_SYMBOL(native_save_fl)
 SYM_FUNC_START(native_restore_fl)
 	push %_ASM_ARG1
 	popf
-	ret
+	RET
 SYM_FUNC_END(native_restore_fl)
 EXPORT_SYMBOL(native_restore_fl)

arch/x86/kernel/kprobes/core.c

@@ -768,7 +768,7 @@ asm(
 	RESTORE_REGS_STRING
 	"	popfl\n"
 #endif
-	"	ret\n"
+	ASM_RET
 	".size kretprobe_trampoline, .-kretprobe_trampoline\n"
 );
 NOKPROBE_SYMBOL(kretprobe_trampoline);

arch/x86/kernel/kvm.c

@@ -953,7 +953,7 @@ asm(
 "movq	__per_cpu_offset(,%rdi,8), %rax;"
 "cmpb	$0, " __stringify(KVM_STEAL_TIME_preempted) "+steal_time(%rax);"
 "setne	%al;"
-"ret;"
+ASM_RET
 ".size __raw_callee_save___kvm_vcpu_is_preempted, .-__raw_callee_save___kvm_vcpu_is_preempted;"
 ".popsection");
 

arch/x86/kernel/module.c

@@ -255,7 +255,8 @@ int module_finalize(const Elf_Ehdr *hdr,
 		    struct module *me)
 {
 	const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL,
-		*para = NULL, *orc = NULL, *orc_ip = NULL;
+		*para = NULL, *orc = NULL, *orc_ip = NULL,
+		*retpolines = NULL, *returns = NULL;
 	char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
 
 	for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
@@ -271,8 +272,20 @@ int module_finalize(const Elf_Ehdr *hdr,
 			orc = s;
 		if (!strcmp(".orc_unwind_ip", secstrings + s->sh_name))
 			orc_ip = s;
+		if (!strcmp(".retpoline_sites", secstrings + s->sh_name))
+			retpolines = s;
+		if (!strcmp(".return_sites", secstrings + s->sh_name))
+			returns = s;
 	}
 
+	if (retpolines) {
+		void *rseg = (void *)retpolines->sh_addr;
+		apply_retpolines(rseg, rseg + retpolines->sh_size);
+	}
+	if (returns) {
+		void *rseg = (void *)returns->sh_addr;
+		apply_returns(rseg, rseg + returns->sh_size);
+	}
 	if (alt) {
 		/* patch .altinstructions */
 		void *aseg = (void *)alt->sh_addr;

arch/x86/kernel/paravirt.c

@@ -40,7 +40,7 @@ extern void _paravirt_nop(void);
 asm (".pushsection .entry.text, \"ax\"\n"
      ".global _paravirt_nop\n"
      "_paravirt_nop:\n\t"
-     "ret\n\t"
+     ASM_RET
      ".size _paravirt_nop, . - _paravirt_nop\n\t"
      ".type _paravirt_nop, @function\n\t"
      ".popsection");

arch/x86/kernel/process.c

@@ -556,7 +556,7 @@ static __always_inline void __speculation_ctrl_update(unsigned long tifp,
 	}
 
 	if (updmsr)
-		wrmsrl(MSR_IA32_SPEC_CTRL, msr);
+		write_spec_ctrl_current(msr, false);
 }
 
 static unsigned long speculation_ctrl_update_tif(struct task_struct *tsk)

arch/x86/kernel/relocate_kernel_32.S

@@ -7,10 +7,12 @@
 #include <linux/linkage.h>
 #include <asm/page_types.h>
 #include <asm/kexec.h>
+#include <asm/nospec-branch.h>
 #include <asm/processor-flags.h>
 
 /*
- * Must be relocatable PIC code callable as a C function
+ * Must be relocatable PIC code callable as a C function, in particular
+ * there must be a plain RET and not jump to return thunk.
  */
 
 #define PTR(x) (x << 2)
@@ -91,7 +93,9 @@ SYM_CODE_START_NOALIGN(relocate_kernel)
 	movl    %edi, %eax
 	addl    $(identity_mapped - relocate_kernel), %eax
 	pushl   %eax
+	ANNOTATE_UNRET_SAFE
 	ret
+	int3
 SYM_CODE_END(relocate_kernel)
 
 SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
@@ -159,12 +163,15 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
 	xorl    %edx, %edx
 	xorl    %esi, %esi
 	xorl    %ebp, %ebp
+	ANNOTATE_UNRET_SAFE
 	ret
+	int3
 1:
 	popl	%edx
 	movl	CP_PA_SWAP_PAGE(%edi), %esp
 	addl	$PAGE_SIZE, %esp
 2:
+	ANNOTATE_RETPOLINE_SAFE
 	call	*%edx
 
 	/* get the re-entry point of the peer system */
@@ -190,7 +197,9 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
 	movl	%edi, %eax
 	addl	$(virtual_mapped - relocate_kernel), %eax
 	pushl	%eax
+	ANNOTATE_UNRET_SAFE
 	ret
+	int3
 SYM_CODE_END(identity_mapped)
 
 SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped)
@@ -208,7 +217,9 @@ SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped)
 	popl	%edi
 	popl	%esi
 	popl	%ebx
+	ANNOTATE_UNRET_SAFE
 	ret
+	int3
 SYM_CODE_END(virtual_mapped)
 
 	/* Do the copies */
@@ -271,7 +282,9 @@ SYM_CODE_START_LOCAL_NOALIGN(swap_pages)
 	popl	%edi
 	popl	%ebx
 	popl	%ebp
+	ANNOTATE_UNRET_SAFE
 	ret
+	int3
 SYM_CODE_END(swap_pages)
 
 	.globl kexec_control_code_size

arch/x86/kernel/relocate_kernel_64.S

@@ -13,7 +13,8 @@
 #include <asm/unwind_hints.h>
 
 /*
- * Must be relocatable PIC code callable as a C function
+ * Must be relocatable PIC code callable as a C function, in particular
+ * there must be a plain RET and not jump to return thunk.
  */
 
 #define PTR(x) (x << 3)
@@ -104,7 +105,9 @@ SYM_CODE_START_NOALIGN(relocate_kernel)
 	/* jump to identity mapped page */
 	addq	$(identity_mapped - relocate_kernel), %r8
 	pushq	%r8
+	ANNOTATE_UNRET_SAFE
 	ret
+	int3
 SYM_CODE_END(relocate_kernel)
 
 SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
@@ -191,7 +194,9 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
 	xorl	%r14d, %r14d
 	xorl	%r15d, %r15d
 
+	ANNOTATE_UNRET_SAFE
 	ret
+	int3
 
 1:
 	popq	%rdx
@@ -210,7 +215,9 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
 	call	swap_pages
 	movq	$virtual_mapped, %rax
 	pushq	%rax
+	ANNOTATE_UNRET_SAFE
 	ret
+	int3
 SYM_CODE_END(identity_mapped)
 
 SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped)
@@ -231,7 +238,9 @@ SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped)
 	popq	%r12
 	popq	%rbp
 	popq	%rbx
+	ANNOTATE_UNRET_SAFE
 	ret
+	int3
 SYM_CODE_END(virtual_mapped)
 
 	/* Do the copies */
@@ -288,7 +297,9 @@ SYM_CODE_START_LOCAL_NOALIGN(swap_pages)
 	lea	PAGE_SIZE(%rax), %rsi
 	jmp	0b
 3:
+	ANNOTATE_UNRET_SAFE
 	ret
+	int3
 SYM_CODE_END(swap_pages)
 
 	.globl kexec_control_code_size

arch/x86/kernel/sev-es.c

@@ -236,7 +236,7 @@ static enum es_result vc_decode_insn(struct es_em_ctxt *ctxt)
 			return ES_EXCEPTION;
 		}
 
-		if (!insn_decode(&ctxt->insn, ctxt->regs, buffer, res))
+		if (!insn_decode_from_regs(&ctxt->insn, ctxt->regs, buffer, res))
 			return ES_DECODE_FAILED;
 	} else {
 		res = vc_fetch_insn_kernel(ctxt, buffer);

arch/x86/kernel/sev_verify_cbit.S

@@ -85,5 +85,5 @@ SYM_FUNC_START(sev_verify_cbit)
 #endif
 	/* Return page-table pointer */
 	movq	%rdi, %rax
-	ret
+	RET
 SYM_FUNC_END(sev_verify_cbit)