Messages in this thread Patch in this message | | | From | Alistair Francis <> | Subject | [PATCH v4 2/4] perf bench futex: Add support for 32-bit systems with 64-bit time_t | Date | Thu, 21 Oct 2021 08:39:18 +1000 |
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From: Alistair Francis <alistair.francis@wdc.com>
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: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Davidlohr Bueso <dbueso@suse.de> --- tools/perf/bench/futex.h | 43 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 40 insertions(+), 3 deletions(-)
diff --git a/tools/perf/bench/futex.h b/tools/perf/bench/futex.h index b97a343e7ec66..6a7dd86871eb8 100644 --- a/tools/perf/bench/futex.h +++ b/tools/perf/bench/futex.h @@ -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, ts32, 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 } /** -- 2.31.1
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