Commit-ID: 7ca0758cdb7c241cb4e0490a8d95f0eb5b861daf Gitweb: http://git.kernel.org/tip/7ca0758cdb7c241cb4e0490a8d95f0eb5b861daf Author: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx> AuthorDate: Mon, 22 Aug 2011 13:27:06 -0700 Committer: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx> CommitDate: Tue, 23 Aug 2011 16:20:10 -0700 x86-32, vdso: On system call restart after SYSENTER, use int $0x80 When we enter a 32-bit system call via SYSENTER or SYSCALL, we shuffle the arguments to match the int $0x80 calling convention. This was probably a design mistake, but it's what it is now. This causes errors if the system call as to be restarted. For SYSENTER, we have to invoke the instruction from the vdso as the return address is hardcoded. Accordingly, we can simply replace the jump in the vdso with an int $0x80 instruction and use the slower entry point for a post-restart. Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/CA%2B55aFztZ=r5wa0x26KJQxvZOaQq8s2v3u50wCyJcA-Sc4g8gQ@xxxxxxxxxxxxxx Cc: <stable@xxxxxxxxxx> --- arch/x86/vdso/vdso32/sysenter.S | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/x86/vdso/vdso32/sysenter.S b/arch/x86/vdso/vdso32/sysenter.S index e2800af..e354bce 100644 --- a/arch/x86/vdso/vdso32/sysenter.S +++ b/arch/x86/vdso/vdso32/sysenter.S @@ -43,7 +43,7 @@ __kernel_vsyscall: .space 7,0x90 /* 14: System call restart point is here! (SYSENTER_RETURN-2) */ - jmp .Lenter_kernel + int $0x80 /* 16: System call normal return point is here! */ VDSO32_SYSENTER_RETURN: /* Symbol used by sysenter.c via vdso32-syms.h */ pop %ebp -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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