Commit-ID: 6fe83695299270f5b813c037dc90492d13786b70 Gitweb: http://git.kernel.org/tip/6fe83695299270f5b813c037dc90492d13786b70 Author: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx> AuthorDate: Mon, 22 Aug 2011 13:27:06 -0700 Committer: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx> CommitDate: Mon, 22 Aug 2011 13:27:06 -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 --- 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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