path: root/arch
diff options
authorH. Peter Anvin <>2011-08-22 13:27:06 -0700
committerH. Peter Anvin <>2011-08-23 16:20:10 -0700
commit7ca0758cdb7c241cb4e0490a8d95f0eb5b861daf (patch)
tree08ec3c3c18fee22ac12d8436ad8f89a5db37226c /arch
parent05e33fc20ea5e493a2a1e7f1d04f43cdf89f83ed (diff)
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 <> Signed-off-by: H. Peter Anvin <> Link: Cc: <>
Diffstat (limited to 'arch')
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/vdso/vdso32/sysenter.S b/arch/x86/vdso/vdso32/sysenter.S
index e2800affa754..e354bceee0e0 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