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 <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230210001210.395194-7-iii@linux.ibm.com

diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c
index 9566d9d2f6eebecbd5eda3a3825b8edca3510665..56374c8b5436d829f0424f96baec79c8c80fbc95 100644 (file)
--- 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 a1e45fec8938edafdace88b9c271a8611099f6e0..3b5dc34d23e995fee210ea01f1ae2830ee2c2b4f 100644 (file)
--- 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;