[PATCH v2 2/2] perf bench: Add support for 32-bit systems with 64-bit time_t
From: Alistair Francis <hidden>
Date: 2021-09-10 04:31:38
Also in:
linux-riscv, lkml
Subsystem:
futex subsystem, performance events subsystem, the rest · Maintainers:
Thomas Gleixner, Ingo Molnar, Peter Zijlstra, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds
From: Alistair Francis <redacted> 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. Signed-off-by: Alistair Francis <redacted> --- tools/perf/bench/futex.h | 43 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 42 insertions(+), 1 deletion(-)
diff --git a/tools/perf/bench/futex.h b/tools/perf/bench/futex.h
index f80a4759ee79b..09c5596726c60 100644
--- a/tools/perf/bench/futex.h
+++ b/tools/perf/bench/futex.h@@ -27,6 +27,12 @@ struct bench_futex_parameters { unsigned int nrequeue; }; +/* A version of 'struct timespec' with 32-bit time_t and nanoseconds. */ +struct __timespec32 { + __kernel_long_t tv_sec; + __kernel_long_t tv_nsec; +}; + /** * futex_syscall() - SYS_futex syscall wrapper * @uaddr: address of first futex
@@ -49,14 +55,49 @@ static inline int futex_syscall(u_int32_t *uaddr, int op, u_int32_t val, struct timespec *timeout, u_int32_t *uaddr2, int val3, int opflags) { - return syscall(SYS_futex, uaddr, op | opflags, val, ts32, uaddr2, val3); +#if defined(SYS_futex_time64) + if (sizeof(*timeout) != sizeof(struct __timespec32)) { + int ret = syscall(SYS_futex_time64, uaddr, op | opflags, val, timeout, + uaddr2, val3); + if (ret == 0 || errno != ENOSYS) + return ret; + } +#endif + +#if defined(SYS_futex) + if (sizeof(*timeout) == sizeof(struct __timespec32)) + return syscall(SYS_futex, uaddr, op | opflags, val, timeout, uaddr2, val3); + + if (timeout && timeout->tv_sec == (long)timeout->tv_sec) { + struct __timespec32 ts32; + + ts32.tv_sec = (__kernel_long_t) timeout->tv_sec; + ts32.tv_nsec = (__kernel_long_t) timeout->tv_nsec; + + return syscall(SYS_futex, uaddr, op | opflags, val, ts32, uaddr2, val3); + } else if (!timeout) { + return syscall(SYS_futex, uaddr, op | opflags, val, NULL, uaddr2, val3); + } +#endif + + errno = ENOSYS; + return -1; } static inline int futex_syscall_nr_requeue(u_int32_t *uaddr, int op, u_int32_t val, int nr_requeue, u_int32_t *uaddr2, int val3, int opflags) { +#if defined(SYS_futex_time64) + int ret = syscall(SYS_futex_time64, uaddr, op | opflags, val, nr_requeue, + uaddr2, val3); + if (ret == 0 || errno != ENOSYS) + return ret; +#endif + +#if defined(SYS_futex) return syscall(SYS_futex, uaddr, op | opflags, val, nr_requeue, uaddr2, val3); +#endif } /**
--
2.31.1