diff options
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/include/asm/vdso/compat_gettimeofday.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/vdso/compat_gettimeofday.h b/arch/arm64/include/asm/vdso/compat_gettimeofday.h index 93dbd935b66d..f4812777f5c5 100644 --- a/arch/arm64/include/asm/vdso/compat_gettimeofday.h +++ b/arch/arm64/include/asm/vdso/compat_gettimeofday.h @@ -12,6 +12,8 @@ #include <asm/vdso/compat_barrier.h> +#define __VDSO_USE_SYSCALL ULLONG_MAX + #define VDSO_HAS_CLOCK_GETRES 1 static __always_inline @@ -74,8 +76,24 @@ static __always_inline u64 __arch_get_hw_counter(s32 clock_mode) { u64 res; + /* + * clock_mode == 0 implies that vDSO are enabled otherwise + * fallback on syscall. + */ + if (clock_mode) + return __VDSO_USE_SYSCALL; + + /* + * This isb() is required to prevent that the counter value + * is speculated. + */ isb(); asm volatile("mrrc p15, 1, %Q0, %R0, c14" : "=r" (res)); + /* + * This isb() is required to prevent that the seq lock is + * speculated. + */ + isb(); return res; } |