Commit c1ff12da authored by Alistair Francis's avatar Alistair Francis Committed by Arnaldo Carvalho de Melo
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perf bench futex: Add support for 32-bit systems with 64-bit time_t 



Some 32-bit architectures (such are 32-bit RISC-V) only have a 64-bit
time_t and as such don't have the SYS_futex syscall. This patch will
allow us to use the SYS_futex_time64 syscall on those platforms.

This also converts the futex calls to be y2038 safe (when built for a
5.1+ kernel).

Signed-off-by: default avatarAlistair Francis <alistair.francis@wdc.com>
Reviewed-by: default avatarArnd Bergmann <arnd@arndb.de>
Acked-by: default avatarDavidlohr Bueso <dbueso@suse.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Francis <alistair23@gmail.com>
Cc: Atish Patra <atish.patra@wdc.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-riscv@lists.infradead.org
Link: http://lore.kernel.org/lkml/20211022013343.2262938-2-alistair.francis@opensource.wdc.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent fec5c3a5

tools/perf/bench/futex.h

+40 −3
Original line number Diff line number Diff line
@@ -8,10 +8,12 @@ 
#ifndef _FUTEX_H

#define _FUTEX_H



#include <errno.h>

#include <unistd.h>

#include <sys/syscall.h>

#include <sys/types.h>

#include <linux/futex.h>

#include <linux/time_types.h>



struct bench_futex_parameters {

	bool silent;
@@ -28,7 +30,7 @@ struct bench_futex_parameters { 
};



/**

 * futex_syscall() - SYS_futex syscall wrapper

 * futex_syscall() - __NR_futex syscall wrapper

 * @uaddr:	address of first futex

 * @op:		futex op code

 * @val:	typically expected value of uaddr, but varies by op
@@ -49,14 +51,49 @@ static inline int 
futex_syscall(volatile u_int32_t *uaddr, int op, u_int32_t val, struct timespec *timeout,

	      volatile u_int32_t *uaddr2, int val3, int opflags)

{

	return syscall(SYS_futex, uaddr, op | opflags, val, timeout, uaddr2, val3);

#if defined(__NR_futex_time64)

	if (sizeof(*timeout) != sizeof(struct __kernel_old_timespec)) {

		int ret =  syscall(__NR_futex_time64, uaddr, op | opflags, val, timeout,

				   uaddr2, val3);

	if (ret == 0 || errno != ENOSYS)

		return ret;

	}

#endif



#if defined(__NR_futex)

	if (sizeof(*timeout) == sizeof(struct __kernel_old_timespec))

		return syscall(__NR_futex, uaddr, op | opflags, val, timeout, uaddr2, val3);



	if (timeout && timeout->tv_sec == (long)timeout->tv_sec) {

		struct __kernel_old_timespec ts32;



		ts32.tv_sec = (__kernel_long_t) timeout->tv_sec;

		ts32.tv_nsec = (__kernel_long_t) timeout->tv_nsec;



		return syscall(__NR_futex, uaddr, op | opflags, val, ts32, uaddr2, val3);

	} else if (!timeout) {

		return syscall(__NR_futex, uaddr, op | opflags, val, NULL, uaddr2, val3);

	}

#endif



	errno = ENOSYS;

	return -1;

}



static inline int

futex_syscall_nr_requeue(volatile u_int32_t *uaddr, int op, u_int32_t val, int nr_requeue,

			 volatile u_int32_t *uaddr2, int val3, int opflags)

{

	return syscall(SYS_futex, uaddr, op | opflags, val, nr_requeue, uaddr2, val3);

#if defined(__NR_futex_time64)

	int ret =  syscall(__NR_futex_time64, uaddr, op | opflags, val, nr_requeue,

			   uaddr2, val3);

	if (ret == 0 || errno != ENOSYS)

		return ret;

#endif



#if defined(__NR_futex)

	return syscall(__NR_futex, uaddr, op | opflags, val, nr_requeue, uaddr2, val3);

#endif

}



/**