From e43002242a47e8d7b2f9446f54de982f09e7dbd1 Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Wed, 8 Jan 2020 11:21:32 -0800 Subject: [PATCH] selftests/bpf: Restore original comm in test_overhead test_overhead changes task comm in order to estimate BPF trampoline overhead but never sets the comm back to the original one. We have the tests (like core_reloc.c) that have 'test_progs' as hard-coded expected comm, so let's try to preserve the original comm. Currently, everything works because the order of execution is: first core_recloc, then test_overhead; but let's make it a bit future-proof. Other related changes: use 'test_overhead' as new comm instead of 'test' to make it easy to debug and drop '\n' at the end. Signed-off-by: Stanislav Fomichev Signed-off-by: Alexei Starovoitov Acked-by: Petar Penkov Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20200108192132.189221-1-sdf@google.com --- tools/testing/selftests/bpf/prog_tests/test_overhead.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/prog_tests/test_overhead.c b/tools/testing/selftests/bpf/prog_tests/test_overhead.c index c32aa28bd93f..465b371a561d 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_overhead.c +++ b/tools/testing/selftests/bpf/prog_tests/test_overhead.c @@ -2,6 +2,7 @@ /* Copyright (c) 2019 Facebook */ #define _GNU_SOURCE #include +#include #include #define MAX_CNT 100000 @@ -17,7 +18,7 @@ static __u64 time_get_ns(void) static int test_task_rename(const char *prog) { int i, fd, duration = 0, err; - char buf[] = "test\n"; + char buf[] = "test_overhead"; __u64 start_time; fd = open("/proc/self/comm", O_WRONLY|O_TRUNC); @@ -66,6 +67,10 @@ void test_test_overhead(void) struct bpf_object *obj; struct bpf_link *link; int err, duration = 0; + char comm[16] = {}; + + if (CHECK_FAIL(prctl(PR_GET_NAME, comm, 0L, 0L, 0L))) + return; obj = bpf_object__open_file("./test_overhead.o", NULL); if (CHECK(IS_ERR(obj), "obj_open_file", "err %ld\n", PTR_ERR(obj))) @@ -138,5 +143,6 @@ void test_test_overhead(void) test_run("fexit"); bpf_link__destroy(link); cleanup: + prctl(PR_SET_NAME, comm, 0L, 0L, 0L); bpf_object__close(obj); }