From: Arnaldo Carvalho de Melo <[email protected]> The 'perf test bpf' was hooking a eBPF program on the SyS_epoll_wait() kernel function, that was what the epoll_wait() glibc function ended up calling, but since at least glibc 2.26, the one that comes with, for instance, Fedora 27, glibc ends up calling SyS_epoll_pwait() when epoll_wait() is used, causing this 'perf test' entry to fail.
So switch to using epoll_pwait() and hook the eBPF program to the SyS_epoll_pwait() kernel function to make it work on a wider range of glibc and kernel versions. Tested-by: Wang Nan <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: David Ahern <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Link: https://lkml.kernel.org/n/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> --- tools/perf/tests/bpf-script-example.c | 4 ++-- tools/perf/tests/bpf.c | 8 ++++---- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/tools/perf/tests/bpf-script-example.c b/tools/perf/tests/bpf-script-example.c index 268e5f8e4aa2..e4123c1b0e88 100644 --- a/tools/perf/tests/bpf-script-example.c +++ b/tools/perf/tests/bpf-script-example.c @@ -31,8 +31,8 @@ struct bpf_map_def SEC("maps") flip_table = { .max_entries = 1, }; -SEC("func=SyS_epoll_wait") -int bpf_func__SyS_epoll_wait(void *ctx) +SEC("func=SyS_epoll_pwait") +int bpf_func__SyS_epoll_pwait(void *ctx) { int ind =0; int *flag = bpf_map_lookup_elem(&flip_table, &ind); diff --git a/tools/perf/tests/bpf.c b/tools/perf/tests/bpf.c index 0512f1b5bfdb..8e709c9d512c 100644 --- a/tools/perf/tests/bpf.c +++ b/tools/perf/tests/bpf.c @@ -19,13 +19,13 @@ #ifdef HAVE_LIBBPF_SUPPORT -static int epoll_wait_loop(void) +static int epoll_pwait_loop(void) { int i; /* Should fail NR_ITERS times */ for (i = 0; i < NR_ITERS; i++) - epoll_wait(-(i + 1), NULL, 0, 0); + epoll_pwait(-(i + 1), NULL, 0, 0, NULL); return 0; } @@ -68,7 +68,7 @@ static struct { .name = "[basic_bpf_test]", .msg_compile_fail = "fix 'perf test LLVM' first", .msg_load_fail = "load bpf object failed", - .target_func = &epoll_wait_loop, + .target_func = &epoll_pwait_loop, .expect_result = (NR_ITERS + 1) / 2, }, { @@ -77,7 +77,7 @@ static struct { .name = "[bpf_pinning]", .msg_compile_fail = "fix kbuild first", .msg_load_fail = "check your vmlinux setting?", - .target_func = &epoll_wait_loop, + .target_func = &epoll_pwait_loop, .expect_result = (NR_ITERS + 1) / 2, .pin = true, }, -- 2.14.3
