5f310f739b
Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/5b99659e8be70f3dd10cd8970a5c90293d9ad9a7.1444091585.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
58 lines
1.2 KiB
ArmAsm
58 lines
1.2 KiB
ArmAsm
/*
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* Code for the vDSO. This version uses the old int $0x80 method.
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*/
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#include <asm/dwarf2.h>
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#include <asm/cpufeature.h>
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#include <asm/alternative-asm.h>
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/*
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* First get the common code for the sigreturn entry points.
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* This must come first.
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*/
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#include "sigreturn.S"
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.text
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.globl __kernel_vsyscall
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.type __kernel_vsyscall,@function
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ALIGN
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__kernel_vsyscall:
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CFI_STARTPROC
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/*
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* Reshuffle regs so that all of any of the entry instructions
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* will preserve enough state.
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*/
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pushl %edx
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET edx, 0
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pushl %ecx
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET ecx, 0
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movl %esp, %ecx
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#ifdef CONFIG_X86_64
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/* If SYSENTER (Intel) or SYSCALL32 (AMD) is available, use it. */
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ALTERNATIVE_2 "", "sysenter", X86_FEATURE_SYSENTER32, \
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"syscall", X86_FEATURE_SYSCALL32
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#else
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ALTERNATIVE "", "sysenter", X86_FEATURE_SEP
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#endif
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/* Enter using int $0x80 */
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movl (%esp), %ecx
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int $0x80
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GLOBAL(int80_landing_pad)
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/* Restore ECX and EDX in case they were clobbered. */
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popl %ecx
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CFI_RESTORE ecx
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CFI_ADJUST_CFA_OFFSET -4
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popl %edx
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CFI_RESTORE edx
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CFI_ADJUST_CFA_OFFSET -4
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ret
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CFI_ENDPROC
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.size __kernel_vsyscall,.-__kernel_vsyscall
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.previous
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