Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 core updates from Ingo Molnar:
 "Note that in this cycle most of the x86 topics interacted at a level
  that caused them to be merged into tip:x86/asm - but this should be a
  temporary phenomenon, hopefully we'll back to the usual patterns in
  the next merge window.

  The main changes in this cycle were:

  Hardware enablement:

   - Add support for the Intel UMIP (User Mode Instruction Prevention)
     CPU feature. This is a security feature that disables certain
     instructions such as SGDT, SLDT, SIDT, SMSW and STR. (Ricardo Neri)

     [ Note that this is disabled by default for now, there are some
       smaller enhancements in the pipeline that I'll follow up with in
       the next 1-2 days, which allows this to be enabled by default.]

   - Add support for the AMD SEV (Secure Encrypted Virtualization) CPU
     feature, on top of SME (Secure Memory Encryption) support that was
     added in v4.14. (Tom Lendacky, Brijesh Singh)

   - Enable new SSE/AVX/AVX512 CPU features: AVX512_VBMI2, GFNI, VAES,
     VPCLMULQDQ, AVX512_VNNI, AVX512_BITALG. (Gayatri Kammela)

  Other changes:

   - A big series of entry code simplifications and enhancements (Andy
     Lutomirski)

   - Make the ORC unwinder default on x86 and various objtool
     enhancements. (Josh Poimboeuf)

   - 5-level paging enhancements (Kirill A. Shutemov)

   - Micro-optimize the entry code a bit (Borislav Petkov)

   - Improve the handling of interdependent CPU features in the early
     FPU init code (Andi Kleen)

   - Build system enhancements (Changbin Du, Masahiro Yamada)

   - ... plus misc enhancements, fixes and cleanups"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (118 commits)
  x86/build: Make the boot image generation less verbose
  selftests/x86: Add tests for the STR and SLDT instructions
  selftests/x86: Add tests for User-Mode Instruction Prevention
  x86/traps: Fix up general protection faults caused by UMIP
  x86/umip: Enable User-Mode Instruction Prevention at runtime
  x86/umip: Force a page fault when unable to copy emulated result to user
  x86/umip: Add emulation code for UMIP instructions
  x86/cpufeature: Add User-Mode Instruction Prevention definitions
  x86/insn-eval: Add support to resolve 16-bit address encodings
  x86/insn-eval: Handle 32-bit address encodings in virtual-8086 mode
  x86/insn-eval: Add wrapper function for 32 and 64-bit addresses
  x86/insn-eval: Add support to resolve 32-bit address encodings
  x86/insn-eval: Compute linear address in several utility functions
  resource: Fix resource_size.cocci warnings
  X86/KVM: Clear encryption attribute when SEV is active
  X86/KVM: Decrypt shared per-cpu variables when SEV is active
  percpu: Introduce DEFINE_PER_CPU_DECRYPTED
  x86: Add support for changing memory encryption attribute in early boot
  x86/io: Unroll string I/O when SEV is active
  x86/boot: Add early boot support when running with SEV active
  ...
This commit is contained in:
Linus Torvalds
2017-11-13 14:13:48 -08:00
110 changed files with 4068 additions and 1146 deletions

View File

@@ -142,56 +142,25 @@ For 32-bit we have the following conventions - kernel is built with
UNWIND_HINT_REGS offset=\offset
.endm
.macro RESTORE_EXTRA_REGS offset=0
movq 0*8+\offset(%rsp), %r15
movq 1*8+\offset(%rsp), %r14
movq 2*8+\offset(%rsp), %r13
movq 3*8+\offset(%rsp), %r12
movq 4*8+\offset(%rsp), %rbp
movq 5*8+\offset(%rsp), %rbx
UNWIND_HINT_REGS offset=\offset extra=0
.macro POP_EXTRA_REGS
popq %r15
popq %r14
popq %r13
popq %r12
popq %rbp
popq %rbx
.endm
.macro RESTORE_C_REGS_HELPER rstor_rax=1, rstor_rcx=1, rstor_r11=1, rstor_r8910=1, rstor_rdx=1
.if \rstor_r11
movq 6*8(%rsp), %r11
.endif
.if \rstor_r8910
movq 7*8(%rsp), %r10
movq 8*8(%rsp), %r9
movq 9*8(%rsp), %r8
.endif
.if \rstor_rax
movq 10*8(%rsp), %rax
.endif
.if \rstor_rcx
movq 11*8(%rsp), %rcx
.endif
.if \rstor_rdx
movq 12*8(%rsp), %rdx
.endif
movq 13*8(%rsp), %rsi
movq 14*8(%rsp), %rdi
UNWIND_HINT_IRET_REGS offset=16*8
.endm
.macro RESTORE_C_REGS
RESTORE_C_REGS_HELPER 1,1,1,1,1
.endm
.macro RESTORE_C_REGS_EXCEPT_RAX
RESTORE_C_REGS_HELPER 0,1,1,1,1
.endm
.macro RESTORE_C_REGS_EXCEPT_RCX
RESTORE_C_REGS_HELPER 1,0,1,1,1
.endm
.macro RESTORE_C_REGS_EXCEPT_R11
RESTORE_C_REGS_HELPER 1,1,0,1,1
.endm
.macro RESTORE_C_REGS_EXCEPT_RCX_R11
RESTORE_C_REGS_HELPER 1,0,0,1,1
.endm
.macro REMOVE_PT_GPREGS_FROM_STACK addskip=0
subq $-(15*8+\addskip), %rsp
.macro POP_C_REGS
popq %r11
popq %r10
popq %r9
popq %r8
popq %rax
popq %rcx
popq %rdx
popq %rsi
popq %rdi
.endm
.macro icebp

View File

@@ -221,10 +221,9 @@ entry_SYSCALL_64_fastpath:
TRACE_IRQS_ON /* user mode is traced as IRQs on */
movq RIP(%rsp), %rcx
movq EFLAGS(%rsp), %r11
RESTORE_C_REGS_EXCEPT_RCX_R11
movq RSP(%rsp), %rsp
addq $6*8, %rsp /* skip extra regs -- they were preserved */
UNWIND_HINT_EMPTY
USERGS_SYSRET64
jmp .Lpop_c_regs_except_rcx_r11_and_sysret
1:
/*
@@ -246,17 +245,18 @@ entry_SYSCALL64_slow_path:
call do_syscall_64 /* returns with IRQs disabled */
return_from_SYSCALL_64:
RESTORE_EXTRA_REGS
TRACE_IRQS_IRETQ /* we're about to change IF */
/*
* Try to use SYSRET instead of IRET if we're returning to
* a completely clean 64-bit userspace context.
* a completely clean 64-bit userspace context. If we're not,
* go to the slow exit path.
*/
movq RCX(%rsp), %rcx
movq RIP(%rsp), %r11
cmpq %rcx, %r11 /* RCX == RIP */
jne opportunistic_sysret_failed
cmpq %rcx, %r11 /* SYSRET requires RCX == RIP */
jne swapgs_restore_regs_and_return_to_usermode
/*
* On Intel CPUs, SYSRET with non-canonical RCX/RIP will #GP
@@ -274,14 +274,14 @@ return_from_SYSCALL_64:
/* If this changed %rcx, it was not canonical */
cmpq %rcx, %r11
jne opportunistic_sysret_failed
jne swapgs_restore_regs_and_return_to_usermode
cmpq $__USER_CS, CS(%rsp) /* CS must match SYSRET */
jne opportunistic_sysret_failed
jne swapgs_restore_regs_and_return_to_usermode
movq R11(%rsp), %r11
cmpq %r11, EFLAGS(%rsp) /* R11 == RFLAGS */
jne opportunistic_sysret_failed
jne swapgs_restore_regs_and_return_to_usermode
/*
* SYSCALL clears RF when it saves RFLAGS in R11 and SYSRET cannot
@@ -302,12 +302,12 @@ return_from_SYSCALL_64:
* would never get past 'stuck_here'.
*/
testq $(X86_EFLAGS_RF|X86_EFLAGS_TF), %r11
jnz opportunistic_sysret_failed
jnz swapgs_restore_regs_and_return_to_usermode
/* nothing to check for RSP */
cmpq $__USER_DS, SS(%rsp) /* SS must match SYSRET */
jne opportunistic_sysret_failed
jne swapgs_restore_regs_and_return_to_usermode
/*
* We win! This label is here just for ease of understanding
@@ -315,14 +315,20 @@ return_from_SYSCALL_64:
*/
syscall_return_via_sysret:
/* rcx and r11 are already restored (see code above) */
RESTORE_C_REGS_EXCEPT_RCX_R11
movq RSP(%rsp), %rsp
UNWIND_HINT_EMPTY
POP_EXTRA_REGS
.Lpop_c_regs_except_rcx_r11_and_sysret:
popq %rsi /* skip r11 */
popq %r10
popq %r9
popq %r8
popq %rax
popq %rsi /* skip rcx */
popq %rdx
popq %rsi
popq %rdi
movq RSP-ORIG_RAX(%rsp), %rsp
USERGS_SYSRET64
opportunistic_sysret_failed:
SWAPGS
jmp restore_c_regs_and_iret
END(entry_SYSCALL_64)
ENTRY(stub_ptregs_64)
@@ -423,8 +429,7 @@ ENTRY(ret_from_fork)
movq %rsp, %rdi
call syscall_return_slowpath /* returns with IRQs disabled */
TRACE_IRQS_ON /* user mode is traced as IRQS on */
SWAPGS
jmp restore_regs_and_iret
jmp swapgs_restore_regs_and_return_to_usermode
1:
/* kernel thread */
@@ -612,8 +617,21 @@ GLOBAL(retint_user)
mov %rsp,%rdi
call prepare_exit_to_usermode
TRACE_IRQS_IRETQ
GLOBAL(swapgs_restore_regs_and_return_to_usermode)
#ifdef CONFIG_DEBUG_ENTRY
/* Assert that pt_regs indicates user mode. */
testb $3, CS(%rsp)
jnz 1f
ud2
1:
#endif
SWAPGS
jmp restore_regs_and_iret
POP_EXTRA_REGS
POP_C_REGS
addq $8, %rsp /* skip regs->orig_ax */
INTERRUPT_RETURN
/* Returning to kernel space */
retint_kernel:
@@ -633,15 +651,17 @@ retint_kernel:
*/
TRACE_IRQS_IRETQ
/*
* At this label, code paths which return to kernel and to user,
* which come from interrupts/exception and from syscalls, merge.
*/
GLOBAL(restore_regs_and_iret)
RESTORE_EXTRA_REGS
restore_c_regs_and_iret:
RESTORE_C_REGS
REMOVE_PT_GPREGS_FROM_STACK 8
GLOBAL(restore_regs_and_return_to_kernel)
#ifdef CONFIG_DEBUG_ENTRY
/* Assert that pt_regs indicates kernel mode. */
testb $3, CS(%rsp)
jz 1f
ud2
1:
#endif
POP_EXTRA_REGS
POP_C_REGS
addq $8, %rsp /* skip regs->orig_ax */
INTERRUPT_RETURN
ENTRY(native_iret)
@@ -818,7 +838,7 @@ ENTRY(\sym)
ASM_CLAC
.ifeq \has_error_code
.if \has_error_code == 0
pushq $-1 /* ORIG_RAX: no syscall to restart */
.endif
@@ -1059,6 +1079,7 @@ idtentry int3 do_int3 has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
idtentry stack_segment do_stack_segment has_error_code=1
#ifdef CONFIG_XEN
idtentry xennmi do_nmi has_error_code=0
idtentry xendebug do_debug has_error_code=0
idtentry xenint3 do_int3 has_error_code=0
#endif
@@ -1112,17 +1133,14 @@ ENTRY(paranoid_exit)
DISABLE_INTERRUPTS(CLBR_ANY)
TRACE_IRQS_OFF_DEBUG
testl %ebx, %ebx /* swapgs needed? */
jnz paranoid_exit_no_swapgs
jnz .Lparanoid_exit_no_swapgs
TRACE_IRQS_IRETQ
SWAPGS_UNSAFE_STACK
jmp paranoid_exit_restore
paranoid_exit_no_swapgs:
jmp .Lparanoid_exit_restore
.Lparanoid_exit_no_swapgs:
TRACE_IRQS_IRETQ_DEBUG
paranoid_exit_restore:
RESTORE_EXTRA_REGS
RESTORE_C_REGS
REMOVE_PT_GPREGS_FROM_STACK 8
INTERRUPT_RETURN
.Lparanoid_exit_restore:
jmp restore_regs_and_return_to_kernel
END(paranoid_exit)
/*
@@ -1223,10 +1241,13 @@ ENTRY(error_exit)
jmp retint_user
END(error_exit)
/* Runs on exception stack */
/* XXX: broken on Xen PV */
/*
* Runs on exception stack. Xen PV does not go through this path at all,
* so we can use real assembly here.
*/
ENTRY(nmi)
UNWIND_HINT_IRET_REGS
/*
* We allow breakpoints in NMIs. If a breakpoint occurs, then
* the iretq it performs will take us out of NMI context.
@@ -1284,7 +1305,7 @@ ENTRY(nmi)
* stacks lest we corrupt the "NMI executing" variable.
*/
SWAPGS_UNSAFE_STACK
swapgs
cld
movq %rsp, %rdx
movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp
@@ -1328,8 +1349,7 @@ ENTRY(nmi)
* Return back to user mode. We must *not* do the normal exit
* work, because we don't want to enable interrupts.
*/
SWAPGS
jmp restore_regs_and_iret
jmp swapgs_restore_regs_and_return_to_usermode
.Lnmi_from_kernel:
/*
@@ -1450,7 +1470,7 @@ nested_nmi_out:
popq %rdx
/* We are returning to kernel mode, so this cannot result in a fault. */
INTERRUPT_RETURN
iretq
first_nmi:
/* Restore rdx. */
@@ -1481,7 +1501,7 @@ first_nmi:
pushfq /* RFLAGS */
pushq $__KERNEL_CS /* CS */
pushq $1f /* RIP */
INTERRUPT_RETURN /* continues at repeat_nmi below */
iretq /* continues at repeat_nmi below */
UNWIND_HINT_IRET_REGS
1:
#endif
@@ -1544,29 +1564,34 @@ end_repeat_nmi:
nmi_swapgs:
SWAPGS_UNSAFE_STACK
nmi_restore:
RESTORE_EXTRA_REGS
RESTORE_C_REGS
POP_EXTRA_REGS
POP_C_REGS
/* Point RSP at the "iret" frame. */
REMOVE_PT_GPREGS_FROM_STACK 6*8
/*
* Skip orig_ax and the "outermost" frame to point RSP at the "iret"
* at the "iret" frame.
*/
addq $6*8, %rsp
/*
* Clear "NMI executing". Set DF first so that we can easily
* distinguish the remaining code between here and IRET from
* the SYSCALL entry and exit paths. On a native kernel, we
* could just inspect RIP, but, on paravirt kernels,
* INTERRUPT_RETURN can translate into a jump into a
* hypercall page.
* the SYSCALL entry and exit paths.
*
* We arguably should just inspect RIP instead, but I (Andy) wrote
* this code when I had the misapprehension that Xen PV supported
* NMIs, and Xen PV would break that approach.
*/
std
movq $0, 5*8(%rsp) /* clear "NMI executing" */
/*
* INTERRUPT_RETURN reads the "iret" frame and exits the NMI
* stack in a single instruction. We are returning to kernel
* mode, so this cannot result in a fault.
* iretq reads the "iret" frame and exits the NMI stack in a
* single instruction. We are returning to kernel mode, so this
* cannot result in a fault. Similarly, we don't need to worry
* about espfix64 on the way back to kernel mode.
*/
INTERRUPT_RETURN
iretq
END(nmi)
ENTRY(ignore_sysret)

View File

@@ -337,8 +337,7 @@ ENTRY(entry_INT80_compat)
/* Go back to user mode. */
TRACE_IRQS_ON
SWAPGS
jmp restore_regs_and_iret
jmp swapgs_restore_regs_and_return_to_usermode
END(entry_INT80_compat)
ENTRY(stub32_clone)

View File

@@ -1,6 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
out := $(obj)/../../include/generated/asm
uapi := $(obj)/../../include/generated/uapi/asm
out := arch/$(SRCARCH)/include/generated/asm
uapi := arch/$(SRCARCH)/include/generated/uapi/asm
# Create output directory if not already present
_dummy := $(shell [ -d '$(out)' ] || mkdir -p '$(out)') \

View File

@@ -114,10 +114,11 @@ static int vvar_fault(const struct vm_special_mapping *sm,
struct pvclock_vsyscall_time_info *pvti =
pvclock_pvti_cpu0_va();
if (pvti && vclock_was_used(VCLOCK_PVCLOCK)) {
ret = vm_insert_pfn(
ret = vm_insert_pfn_prot(
vma,
vmf->address,
__pa(pvti) >> PAGE_SHIFT);
__pa(pvti) >> PAGE_SHIFT,
pgprot_decrypted(vma->vm_page_prot));
}
} else if (sym_offset == image->sym_hvclock_page) {
struct ms_hyperv_tsc_page *tsc_pg = hv_get_tsc_page();