diff options
| author | Andy Lutomirski <luto@kernel.org> | 2020-06-26 10:21:16 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-07-01 10:00:27 +0200 |
| commit | cced0b24bb545bfe74fea96de84adc23c0146b05 (patch) | |
| tree | 4cf94eb54ae3f64b4c4b54c696f0e5fabd081078 /tools/testing/selftests/x86/unwind_vdso.c | |
| parent | a61fa2799ef9bf6c4f54cf7295036577cececc72 (diff) | |
selftests/x86: Consolidate and fix get/set_eflags() helpers
There are several copies of get_eflags() and set_eflags() and they all are
buggy. Consolidate them and fix them. The fixes are:
Add memory clobbers. These are probably unnecessary but they make sure
that the compiler doesn't move something past one of these calls when it
shouldn't.
Respect the redzone on x86_64. There has no failure been observed related
to this, but it's definitely a bug.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/982ce58ae8dea2f1e57093ee894760e35267e751.1593191971.git.luto@kernel.org
Diffstat (limited to 'tools/testing/selftests/x86/unwind_vdso.c')
| -rw-r--r-- | tools/testing/selftests/x86/unwind_vdso.c | 23 |
1 files changed, 2 insertions, 21 deletions
diff --git a/tools/testing/selftests/x86/unwind_vdso.c b/tools/testing/selftests/x86/unwind_vdso.c index 0075ccd65407..4c311e1af4c7 100644 --- a/tools/testing/selftests/x86/unwind_vdso.c +++ b/tools/testing/selftests/x86/unwind_vdso.c @@ -11,6 +11,8 @@ #include <features.h> #include <stdio.h> +#include "helpers.h" + #if defined(__GLIBC__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 16 int main() @@ -53,27 +55,6 @@ static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *), err(1, "sigaction"); } -#ifdef __x86_64__ -# define WIDTH "q" -#else -# define WIDTH "l" -#endif - -static unsigned long get_eflags(void) -{ - unsigned long eflags; - asm volatile ("pushf" WIDTH "\n\tpop" WIDTH " %0" : "=rm" (eflags)); - return eflags; -} - -static void set_eflags(unsigned long eflags) -{ - asm volatile ("push" WIDTH " %0\n\tpopf" WIDTH - : : "rm" (eflags) : "flags"); -} - -#define X86_EFLAGS_TF (1UL << 8) - static volatile sig_atomic_t nerrs; static unsigned long sysinfo; static bool got_sysinfo = false; |