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linux/arch/x86/entry/vdso/vclock_gettime.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Fast user context implementation of clock_gettime, gettimeofday, and time.
*
* Copyright 2006 Andi Kleen, SUSE Labs.
* Copyright 2019 ARM Limited
*
* 32 Bit compat layer by Stefani Seibold <stefani@seibold.net>
* sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany
*/
#include <linux/time.h>
#include <linux/kernel.h>
#include <linux/types.h>
arch: vdso: consolidate gettime prototypes The VDSO functions are defined as globals in the kernel sources but intended to be called from userspace, so there is no need to declare them in a kernel side header. Without a prototype, this now causes warnings such as arch/mips/vdso/vgettimeofday.c:14:5: error: no previous prototype for '__vdso_clock_gettime' [-Werror=missing-prototypes] arch/mips/vdso/vgettimeofday.c:28:5: error: no previous prototype for '__vdso_gettimeofday' [-Werror=missing-prototypes] arch/mips/vdso/vgettimeofday.c:36:5: error: no previous prototype for '__vdso_clock_getres' [-Werror=missing-prototypes] arch/mips/vdso/vgettimeofday.c:42:5: error: no previous prototype for '__vdso_clock_gettime64' [-Werror=missing-prototypes] arch/sparc/vdso/vclock_gettime.c:254:1: error: no previous prototype for '__vdso_clock_gettime' [-Werror=missing-prototypes] arch/sparc/vdso/vclock_gettime.c:282:1: error: no previous prototype for '__vdso_clock_gettime_stick' [-Werror=missing-prototypes] arch/sparc/vdso/vclock_gettime.c:307:1: error: no previous prototype for '__vdso_gettimeofday' [-Werror=missing-prototypes] arch/sparc/vdso/vclock_gettime.c:343:1: error: no previous prototype for '__vdso_gettimeofday_stick' [-Werror=missing-prototypes] Most architectures have already added workarounds for these by adding declarations somewhere, but since these are all compatible, we should really just have one copy, with an #ifdef check for the 32-bit vs 64-bit variant and use that everywhere. Unfortunately, the sparc an um versions are currently incompatible since they never added support for __vdso_clock_gettime64() in 32-bit userland. For the moment, I'm leaving this one out, as I can't easily test it and it requires a larger rework. Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2023-11-08 05:58:36 -07:00
#include <vdso/gettime.h>
#include "../../../../lib/vdso/gettimeofday.c"
int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
{
return __cvdso_gettimeofday(tv, tz);
}
int gettimeofday(struct __kernel_old_timeval *, struct timezone *)
__attribute__((weak, alias("__vdso_gettimeofday")));
__kernel_old_time_t __vdso_time(__kernel_old_time_t *t)
{
return __cvdso_time(t);
}
__kernel_old_time_t time(__kernel_old_time_t *t) __attribute__((weak, alias("__vdso_time")));
#if defined(CONFIG_X86_64) && !defined(BUILD_VDSO32_64)
/* both 64-bit and x32 use these */
int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts)
{
return __cvdso_clock_gettime(clock, ts);
}
int clock_gettime(clockid_t, struct __kernel_timespec *)
__attribute__((weak, alias("__vdso_clock_gettime")));
x86/vdso: Introduce and use vgtod_ts It's desired to support more clocks in the VDSO, e.g. CLOCK_TAI. This results either in indirect calls due to the larger switch case, which then requires retpolines or when the compiler is forced to avoid jump tables it results in even more conditionals. To avoid both variants which are bad for performance the high resolution functions and the coarse grained functions will be collapsed into one for each. That requires to store the clock specific base time in an array. Introcude struct vgtod_ts for storage and convert the data store, the update function and the individual clock functions over to use it. The new storage does not longer use gtod_long_t for seconds depending on 32 or 64 bit compile because this needs to be the full 64bit value even for 32bit when a Y2038 function is added. No point in keeping the distinction alive in the internal representation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Matt Rickard <matt@softrans.com.au> Cc: Stephen Boyd <sboyd@kernel.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Florian Weimer <fweimer@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: devel@linuxdriverproject.org Cc: virtualization@lists.linux-foundation.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Juergen Gross <jgross@suse.com> Link: https://lkml.kernel.org/r/20180917130707.324679401@linutronix.de
2018-09-17 05:45:38 -07:00
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 */
int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts)
{
return __cvdso_clock_gettime32(clock, ts);
}
int clock_gettime(clockid_t, struct old_timespec32 *)
__attribute__((weak, alias("__vdso_clock_gettime")));
int __vdso_clock_gettime64(clockid_t clock, struct __kernel_timespec *ts)
{
return __cvdso_clock_gettime(clock, ts);
}
int clock_gettime64(clockid_t, struct __kernel_timespec *)
__attribute__((weak, alias("__vdso_clock_gettime64")));
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