From 202702e890a41412a7de970b84a970ba1d5001c9 Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Fri, 10 Feb 2023 01:12:00 +0100 Subject: [PATCH] selftests/bpf: Attach to fopen()/fclose() in attach_probe malloc() and free() may be completely replaced by sanitizers, use fopen() and fclose() instead. Signed-off-by: Ilya Leoshkevich Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20230210001210.395194-7-iii@linux.ibm.com --- tools/testing/selftests/bpf/prog_tests/attach_probe.c | 10 +++++----- tools/testing/selftests/bpf/progs/test_attach_probe.c | 11 ++++++----- 2 files changed, 11 insertions(+), 10 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c index 9566d9d2f6ee..56374c8b5436 100644 --- a/tools/testing/selftests/bpf/prog_tests/attach_probe.c +++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c @@ -33,8 +33,8 @@ void test_attach_probe(void) struct test_attach_probe* skel; ssize_t uprobe_offset, ref_ctr_offset; struct bpf_link *uprobe_err_link; + FILE *devnull; bool legacy; - char *mem; /* Check if new-style kprobe/uprobe API is supported. * Kernels that support new FD-based kprobe and uprobe BPF attachment @@ -147,7 +147,7 @@ void test_attach_probe(void) /* test attach by name for a library function, using the library * as the binary argument. libc.so.6 will be resolved via dlopen()/dlinfo(). */ - uprobe_opts.func_name = "malloc"; + uprobe_opts.func_name = "fopen"; uprobe_opts.retprobe = false; skel->links.handle_uprobe_byname2 = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname2, @@ -157,7 +157,7 @@ void test_attach_probe(void) if (!ASSERT_OK_PTR(skel->links.handle_uprobe_byname2, "attach_uprobe_byname2")) goto cleanup; - uprobe_opts.func_name = "free"; + uprobe_opts.func_name = "fclose"; uprobe_opts.retprobe = true; skel->links.handle_uretprobe_byname2 = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe_byname2, @@ -195,8 +195,8 @@ void test_attach_probe(void) usleep(1); /* trigger & validate shared library u[ret]probes attached by name */ - mem = malloc(1); - free(mem); + devnull = fopen("/dev/null", "r"); + fclose(devnull); /* trigger & validate uprobe & uretprobe */ trigger_func(); diff --git a/tools/testing/selftests/bpf/progs/test_attach_probe.c b/tools/testing/selftests/bpf/progs/test_attach_probe.c index a1e45fec8938..3b5dc34d23e9 100644 --- a/tools/testing/selftests/bpf/progs/test_attach_probe.c +++ b/tools/testing/selftests/bpf/progs/test_attach_probe.c @@ -92,18 +92,19 @@ int handle_uretprobe_byname(struct pt_regs *ctx) } SEC("uprobe") -int handle_uprobe_byname2(struct pt_regs *ctx) +int BPF_UPROBE(handle_uprobe_byname2, const char *pathname, const char *mode) { - unsigned int size = PT_REGS_PARM1(ctx); + char mode_buf[2] = {}; - /* verify malloc size */ - if (size == 1) + /* verify fopen mode */ + bpf_probe_read_user(mode_buf, sizeof(mode_buf), mode); + if (mode_buf[0] == 'r' && mode_buf[1] == 0) uprobe_byname2_res = 7; return 0; } SEC("uretprobe") -int handle_uretprobe_byname2(struct pt_regs *ctx) +int BPF_URETPROBE(handle_uretprobe_byname2, void *ret) { uretprobe_byname2_res = 8; return 0;