From 02e425668f5c9deb42787d10001a3b605993ad15 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Wed, 3 Oct 2018 16:23:49 -0700 Subject: x86/vdso: Fix vDSO syscall fallback asm constraint regression When I added the missing memory outputs, I failed to update the index of the first argument (ebx) on 32-bit builds, which broke the fallbacks. Somehow I must have screwed up my testing or gotten lucky. Add another test to cover gettimeofday() as well. Signed-off-by: Andy Lutomirski Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: stable@vger.kernel.org Fixes: 715bd9d12f84 ("x86/vdso: Fix asm constraints on vDSO syscall fallbacks") Link: http://lkml.kernel.org/r/21bd45ab04b6d838278fa5bebfa9163eceffa13c.1538608971.git.luto@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/entry/vdso/vclock_gettime.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'arch') diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c index 134e2d2e8add..e48ca3afa091 100644 --- a/arch/x86/entry/vdso/vclock_gettime.c +++ b/arch/x86/entry/vdso/vclock_gettime.c @@ -68,11 +68,11 @@ notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) asm ( "mov %%ebx, %%edx \n" - "mov %2, %%ebx \n" + "mov %[clock], %%ebx \n" "call __kernel_vsyscall \n" "mov %%edx, %%ebx \n" : "=a" (ret), "=m" (*ts) - : "0" (__NR_clock_gettime), "g" (clock), "c" (ts) + : "0" (__NR_clock_gettime), [clock] "g" (clock), "c" (ts) : "memory", "edx"); return ret; } @@ -83,11 +83,11 @@ notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz) asm ( "mov %%ebx, %%edx \n" - "mov %2, %%ebx \n" + "mov %[tv], %%ebx \n" "call __kernel_vsyscall \n" "mov %%edx, %%ebx \n" : "=a" (ret), "=m" (*tv), "=m" (*tz) - : "0" (__NR_gettimeofday), "g" (tv), "c" (tz) + : "0" (__NR_gettimeofday), [tv] "g" (tv), "c" (tz) : "memory", "edx"); return ret; } -- cgit v1.2.3