From f66501dc53e72079045a6a17e023b41316ede220 Mon Sep 17 00:00:00 2001 From: Vincenzo Frascino Date: Fri, 21 Jun 2019 10:52:50 +0100 Subject: [PATCH] x86/vdso: Add clock_getres() entry point The generic vDSO library provides an implementation of clock_getres() that can be leveraged by each architecture. Add the clock_getres() VDSO entry point on x86. [ tglx: Massaged changelog and cleaned up the function signature formatting ] Signed-off-by: Vincenzo Frascino Signed-off-by: Thomas Gleixner Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: Catalin Marinas Cc: Will Deacon Cc: Arnd Bergmann Cc: Russell King Cc: Ralf Baechle Cc: Paul Burton Cc: Daniel Lezcano Cc: Mark Salyzyn Cc: Peter Collingbourne Cc: Shuah Khan Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Rasmus Villemoes Cc: Huw Davies Cc: Shijith Thotton Cc: Andre Przywara Link: https://lkml.kernel.org/r/20190621095252.32307-24-vincenzo.frascino@arm.com --- arch/x86/entry/vdso/vclock_gettime.c | 17 +++++++++++++ arch/x86/entry/vdso/vdso.lds.S | 2 ++ arch/x86/entry/vdso/vdso32/vdso32.lds.S | 1 + arch/x86/include/asm/vdso/gettimeofday.h | 31 ++++++++++++++++++++++++ 4 files changed, 51 insertions(+) diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c index f01a3f0787ca..1a648b509d46 100644 --- a/arch/x86/entry/vdso/vclock_gettime.c +++ b/arch/x86/entry/vdso/vclock_gettime.c @@ -36,6 +36,7 @@ time_t time(time_t *t) __attribute__((weak, alias("__vdso_time"))); #if defined(CONFIG_X86_64) && !defined(BUILD_VDSO32_64) /* both 64-bit and x32 use these */ extern int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts); +extern int __vdso_clock_getres(clockid_t clock, struct __kernel_timespec *res); int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts) { @@ -45,9 +46,18 @@ int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts) int clock_gettime(clockid_t, struct __kernel_timespec *) __attribute__((weak, alias("__vdso_clock_gettime"))); +int __vdso_clock_getres(clockid_t clock, + struct __kernel_timespec *res) +{ + return __cvdso_clock_getres(clock, res); +} +int clock_getres(clockid_t, struct __kernel_timespec *) + __attribute__((weak, alias("__vdso_clock_getres"))); + #else /* i386 only */ extern int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts); +extern int __vdso_clock_getres(clockid_t clock, struct old_timespec32 *res); int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts) { @@ -57,4 +67,11 @@ int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts) int clock_gettime(clockid_t, struct old_timespec32 *) __attribute__((weak, alias("__vdso_clock_gettime"))); +int __vdso_clock_getres(clockid_t clock, struct old_timespec32 *res) +{ + return __cvdso_clock_getres_time32(clock, res); +} + +int clock_getres(clockid_t, struct old_timespec32 *) + __attribute__((weak, alias("__vdso_clock_getres"))); #endif diff --git a/arch/x86/entry/vdso/vdso.lds.S b/arch/x86/entry/vdso/vdso.lds.S index d3a2dce4cfa9..36b644e16272 100644 --- a/arch/x86/entry/vdso/vdso.lds.S +++ b/arch/x86/entry/vdso/vdso.lds.S @@ -25,6 +25,8 @@ VERSION { __vdso_getcpu; time; __vdso_time; + clock_getres; + __vdso_clock_getres; local: *; }; } diff --git a/arch/x86/entry/vdso/vdso32/vdso32.lds.S b/arch/x86/entry/vdso/vdso32/vdso32.lds.S index 422764a81d32..991b26cc855b 100644 --- a/arch/x86/entry/vdso/vdso32/vdso32.lds.S +++ b/arch/x86/entry/vdso/vdso32/vdso32.lds.S @@ -26,6 +26,7 @@ VERSION __vdso_clock_gettime; __vdso_gettimeofday; __vdso_time; + __vdso_clock_getres; }; LINUX_2.5 { diff --git a/arch/x86/include/asm/vdso/gettimeofday.h b/arch/x86/include/asm/vdso/gettimeofday.h index 0e2650fc191b..f92752d6cbcf 100644 --- a/arch/x86/include/asm/vdso/gettimeofday.h +++ b/arch/x86/include/asm/vdso/gettimeofday.h @@ -24,6 +24,8 @@ #define VDSO_HAS_TIME 1 +#define VDSO_HAS_CLOCK_GETRES 1 + #ifdef CONFIG_PARAVIRT_CLOCK extern u8 pvclock_page[PAGE_SIZE] __attribute__((visibility("hidden"))); @@ -60,6 +62,18 @@ long gettimeofday_fallback(struct __kernel_old_timeval *_tv, return ret; } +static __always_inline +long clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts) +{ + long ret; + + asm ("syscall" : "=a" (ret), "=m" (*_ts) : + "0" (__NR_clock_getres), "D" (_clkid), "S" (_ts) : + "rcx", "r11"); + + return ret; +} + #else static __always_inline @@ -97,6 +111,23 @@ long gettimeofday_fallback(struct __kernel_old_timeval *_tv, return ret; } +static __always_inline long +clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts) +{ + long ret; + + asm ( + "mov %%ebx, %%edx \n" + "mov %[clock], %%ebx \n" + "call __kernel_vsyscall \n" + "mov %%edx, %%ebx \n" + : "=a" (ret), "=m" (*_ts) + : "0" (__NR_clock_getres_time64), [clock] "g" (_clkid), "c" (_ts) + : "edx"); + + return ret; +} + #endif #ifdef CONFIG_PARAVIRT_CLOCK -- 2.30.2