From fa7f17d066bd0996b930b664aa0ed1f213fc1828 Mon Sep 17 00:00:00 2001 From: Hou Tao Date: Mon, 4 Oct 2021 17:48:57 +0800 Subject: bpf/selftests: Add test for writable bare tracepoint Add a writable bare tracepoint in bpf_testmod module, and trigger its calling when reading /sys/kernel/bpf_testmod with a specific buffer length. The reading will return the value in writable context if the early return flag is enabled in writable context. Signed-off-by: Hou Tao Signed-off-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211004094857.30868-4-hotforest@gmail.com --- .../selftests/bpf/prog_tests/module_attach.c | 35 ++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'tools/testing/selftests/bpf/prog_tests/module_attach.c') diff --git a/tools/testing/selftests/bpf/prog_tests/module_attach.c b/tools/testing/selftests/bpf/prog_tests/module_attach.c index 1797a6e4d6d8..6d0e50dcf47c 100644 --- a/tools/testing/selftests/bpf/prog_tests/module_attach.c +++ b/tools/testing/selftests/bpf/prog_tests/module_attach.c @@ -2,10 +2,36 @@ /* Copyright (c) 2020 Facebook */ #include +#include #include "test_module_attach.skel.h" static int duration; +static int trigger_module_test_writable(int *val) +{ + int fd, err; + char buf[65]; + ssize_t rd; + + fd = open(BPF_TESTMOD_TEST_FILE, O_RDONLY); + err = -errno; + if (!ASSERT_GE(fd, 0, "testmode_file_open")) + return err; + + rd = read(fd, buf, sizeof(buf) - 1); + err = -errno; + if (!ASSERT_GT(rd, 0, "testmod_file_rd_val")) { + close(fd); + return err; + } + + buf[rd] = '\0'; + *val = strtol(buf, NULL, 0); + close(fd); + + return 0; +} + static int delete_module(const char *name, int flags) { return syscall(__NR_delete_module, name, flags); @@ -19,6 +45,7 @@ void test_module_attach(void) struct test_module_attach__bss *bss; struct bpf_link *link; int err; + int writable_val = 0; skel = test_module_attach__open(); if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) @@ -51,6 +78,14 @@ void test_module_attach(void) ASSERT_EQ(bss->fexit_ret, -EIO, "fexit_tet"); ASSERT_EQ(bss->fmod_ret_read_sz, READ_SZ, "fmod_ret"); + bss->raw_tp_writable_bare_early_ret = true; + bss->raw_tp_writable_bare_out_val = 0xf1f2f3f4; + ASSERT_OK(trigger_module_test_writable(&writable_val), + "trigger_writable"); + ASSERT_EQ(bss->raw_tp_writable_bare_in_val, 1024, "writable_test_in"); + ASSERT_EQ(bss->raw_tp_writable_bare_out_val, writable_val, + "writable_test_out"); + test_module_attach__detach(skel); /* attach fentry/fexit and make sure it get's module reference */ -- cgit