FROMLIST: [PATCH v5 06/12] arm: vdso: add support for clock_getres

(cherry picked from url https://patchwork.kernel.org/patch/10044545/)

Take an effort to recode the arm64 vdso code from assembler to C
previously submitted by Andrew Pinski <apinski@cavium.com>, rework
it for use in both arm and arm64, overlapping any optimizations
for each architecture. But instead of landing it in arm64, land the
result into lib/vdso and unify both implementations to simplify
future maintenance.

Add clock_getres vdso support to match up with existing support in
the arm64's vdso.

Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Cc: James Morse <james.morse@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Andy Gross <andy.gross@linaro.org>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Andrew Pinski <apinski@cavium.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Bug: 63737556
Bug: 20045882
Change-Id: Ie37bf76d2992027f06a2cdd001d8654a860d2aac
This commit is contained in:
Mark Salyzyn 2017-08-17 09:16:27 -07:00 committed by Timi
parent d1fe361d48
commit eb1f240a10
4 changed files with 26 additions and 0 deletions

View file

@ -173,6 +173,7 @@ static void __init patch_vdso(void *ehdr)
if (!cntvct_ok) {
vdso_nullpatch_one(&einfo, "__vdso_gettimeofday");
vdso_nullpatch_one(&einfo, "__vdso_clock_gettime");
vdso_nullpatch_one(&einfo, "__vdso_clock_getres");
}
}

View file

@ -27,6 +27,7 @@
#include <asm/processor.h> /* for cpu_relax() */
#include <asm/unistd.h>
#include <linux/compiler.h>
#include <linux/hrtimer.h> /* for LOW_RES_NSEC and MONOTONIC_RES_NSEC */
#include <linux/time.h> /* for NSEC_PER_SEC */
#ifndef CONFIG_AEABI

View file

@ -82,6 +82,7 @@ VERSION
global:
__vdso_clock_gettime;
__vdso_gettimeofday;
__vdso_clock_getres;
local: *;
};
}

View file

@ -32,6 +32,7 @@
DEFINE_FALLBACK(gettimeofday, struct timeval *, tv, struct timezone *, tz)
DEFINE_FALLBACK(clock_gettime, clockid_t, clock, struct timespec *, ts)
DEFINE_FALLBACK(clock_getres, clockid_t, clock, struct timespec *, ts)
static notrace u32 vdso_read_begin(const struct vdso_data *vd)
{
@ -301,3 +302,25 @@ notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz)
return 0;
}
int __vdso_clock_getres(clockid_t clock, struct timespec *res)
{
long nsec;
if (clock == CLOCK_REALTIME ||
clock == CLOCK_MONOTONIC ||
clock == CLOCK_MONOTONIC_RAW)
nsec = MONOTONIC_RES_NSEC;
else if (clock == CLOCK_REALTIME_COARSE ||
clock == CLOCK_MONOTONIC_COARSE)
nsec = LOW_RES_NSEC;
else
return clock_getres_fallback(clock, res);
if (likely(res != NULL)) {
res->tv_sec = 0;
res->tv_nsec = nsec;
}
return 0;
}