Merge branch 'linus' into sched/urgent, to resolve conflicts
Conflicts: arch/arm64/kernel/entry.S arch/x86/Kconfig include/linux/sched/mm.h kernel/fork.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ingo Molnar
@@ -236,91 +236,20 @@ GLOBAL(entry_SYSCALL_64_after_hwframe)
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pushq %r9 /* pt_regs->r9 */
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pushq %r10 /* pt_regs->r10 */
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pushq %r11 /* pt_regs->r11 */
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sub $(6*8), %rsp /* pt_regs->bp, bx, r12-15 not saved */
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UNWIND_HINT_REGS extra=0
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pushq %rbx /* pt_regs->rbx */
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pushq %rbp /* pt_regs->rbp */
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pushq %r12 /* pt_regs->r12 */
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pushq %r13 /* pt_regs->r13 */
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pushq %r14 /* pt_regs->r14 */
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pushq %r15 /* pt_regs->r15 */
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UNWIND_HINT_REGS
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TRACE_IRQS_OFF
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/*
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* If we need to do entry work or if we guess we'll need to do
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* exit work, go straight to the slow path.
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*/
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movq PER_CPU_VAR(current_task), %r11
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testl $_TIF_WORK_SYSCALL_ENTRY|_TIF_ALLWORK_MASK, TASK_TI_flags(%r11)
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jnz entry_SYSCALL64_slow_path
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entry_SYSCALL_64_fastpath:
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/*
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* Easy case: enable interrupts and issue the syscall. If the syscall
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* needs pt_regs, we'll call a stub that disables interrupts again
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* and jumps to the slow path.
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*/
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TRACE_IRQS_ON
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ENABLE_INTERRUPTS(CLBR_NONE)
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#if __SYSCALL_MASK == ~0
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cmpq $__NR_syscall_max, %rax
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#else
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andl $__SYSCALL_MASK, %eax
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cmpl $__NR_syscall_max, %eax
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#endif
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ja 1f /* return -ENOSYS (already in pt_regs->ax) */
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movq %r10, %rcx
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/*
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* This call instruction is handled specially in stub_ptregs_64.
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* It might end up jumping to the slow path. If it jumps, RAX
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* and all argument registers are clobbered.
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*/
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#ifdef CONFIG_RETPOLINE
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movq sys_call_table(, %rax, 8), %rax
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call __x86_indirect_thunk_rax
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#else
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call *sys_call_table(, %rax, 8)
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#endif
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.Lentry_SYSCALL_64_after_fastpath_call:
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movq %rax, RAX(%rsp)
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1:
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/*
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* If we get here, then we know that pt_regs is clean for SYSRET64.
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* If we see that no exit work is required (which we are required
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* to check with IRQs off), then we can go straight to SYSRET64.
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*/
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DISABLE_INTERRUPTS(CLBR_ANY)
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TRACE_IRQS_OFF
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movq PER_CPU_VAR(current_task), %r11
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testl $_TIF_ALLWORK_MASK, TASK_TI_flags(%r11)
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jnz 1f
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LOCKDEP_SYS_EXIT
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TRACE_IRQS_ON /* user mode is traced as IRQs on */
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movq RIP(%rsp), %rcx
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movq EFLAGS(%rsp), %r11
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addq $6*8, %rsp /* skip extra regs -- they were preserved */
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UNWIND_HINT_EMPTY
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jmp .Lpop_c_regs_except_rcx_r11_and_sysret
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1:
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/*
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* The fast path looked good when we started, but something changed
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* along the way and we need to switch to the slow path. Calling
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* raise(3) will trigger this, for example. IRQs are off.
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*/
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TRACE_IRQS_ON
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ENABLE_INTERRUPTS(CLBR_ANY)
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SAVE_EXTRA_REGS
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movq %rsp, %rdi
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call syscall_return_slowpath /* returns with IRQs disabled */
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jmp return_from_SYSCALL_64
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entry_SYSCALL64_slow_path:
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/* IRQs are off. */
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SAVE_EXTRA_REGS
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movq %rsp, %rdi
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call do_syscall_64 /* returns with IRQs disabled */
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return_from_SYSCALL_64:
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TRACE_IRQS_IRETQ /* we're about to change IF */
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/*
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@@ -393,7 +322,6 @@ syscall_return_via_sysret:
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/* rcx and r11 are already restored (see code above) */
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UNWIND_HINT_EMPTY
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POP_EXTRA_REGS
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.Lpop_c_regs_except_rcx_r11_and_sysret:
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popq %rsi /* skip r11 */
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popq %r10
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popq %r9
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@@ -424,47 +352,6 @@ syscall_return_via_sysret:
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USERGS_SYSRET64
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END(entry_SYSCALL_64)
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ENTRY(stub_ptregs_64)
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/*
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* Syscalls marked as needing ptregs land here.
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* If we are on the fast path, we need to save the extra regs,
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* which we achieve by trying again on the slow path. If we are on
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* the slow path, the extra regs are already saved.
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*
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* RAX stores a pointer to the C function implementing the syscall.
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* IRQs are on.
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*/
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cmpq $.Lentry_SYSCALL_64_after_fastpath_call, (%rsp)
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jne 1f
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/*
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* Called from fast path -- disable IRQs again, pop return address
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* and jump to slow path
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*/
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DISABLE_INTERRUPTS(CLBR_ANY)
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TRACE_IRQS_OFF
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popq %rax
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UNWIND_HINT_REGS extra=0
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jmp entry_SYSCALL64_slow_path
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1:
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JMP_NOSPEC %rax /* Called from C */
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END(stub_ptregs_64)
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.macro ptregs_stub func
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ENTRY(ptregs_\func)
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UNWIND_HINT_FUNC
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leaq \func(%rip), %rax
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jmp stub_ptregs_64
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END(ptregs_\func)
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.endm
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/* Instantiate ptregs_stub for each ptregs-using syscall */
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#define __SYSCALL_64_QUAL_(sym)
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#define __SYSCALL_64_QUAL_ptregs(sym) ptregs_stub sym
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#define __SYSCALL_64(nr, sym, qual) __SYSCALL_64_QUAL_##qual(sym)
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#include <asm/syscalls_64.h>
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/*
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* %rdi: prev task
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* %rsi: next task
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