On Wed, Feb 8, 2023 at 12:57 PM Ilya Leoshkevich <iii@xxxxxxxxxxxxx> wrote:
>
> malloc() and free() may be completely replaced by sanitizers, use
> fopen() and fclose() instead.
>
> Signed-off-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx>
> ---
> tools/testing/selftests/bpf/prog_tests/attach_probe.c | 10 +++++-----
> tools/testing/selftests/bpf/progs/test_attach_probe.c | 8 +++++---
> 2 files changed, 10 insertions(+), 8 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..269a184c265c 100644
> --- a/tools/testing/selftests/bpf/progs/test_attach_probe.c
> +++ b/tools/testing/selftests/bpf/progs/test_attach_probe.c
> @@ -94,10 +94,12 @@ int handle_uretprobe_byname(struct pt_regs *ctx)
> SEC("uprobe")
> int handle_uprobe_byname2(struct pt_regs *ctx)
> {
> - unsigned int size = PT_REGS_PARM1(ctx);
> + void *mode_ptr = (void *)(long)PT_REGS_PARM2(ctx);
let's use BPF_UPROBE() macro instead of PT_REGS_xxx() calls?
> + char mode[2] = {};
>
> - /* verify malloc size */
> - if (size == 1)
> + /* verify fopen mode */
> + bpf_probe_read_user(mode, sizeof(mode), mode_ptr);
> + if (mode[0] == 'r' && mode[1] == 0)
> uprobe_byname2_res = 7;
> return 0;
> }
> --
> 2.39.1
>
