On Thu, Apr 21, 2022 at 9:53 AM Daniel Borkmann <daniel@xxxxxxxxxxxxx> wrote: > > On 4/21/22 3:23 PM, Artem Savkov wrote: > > I am getting the following compilation error for prog_tests/uprobe_autoattach.c > > > > tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c: In function ‘test_uprobe_autoattach’: > > ./test_progs.h:209:26: error: pointer ‘mem’ may be used after ‘free’ [-Werror=use-after-free] > > > > mem variable is now used in one of the asserts so it shouldn't be freed right > > away. Move free(mem) after the assert block. > > Looks good, but I rephrased this a bit to avoid confusion. It's false positive given we > only compare the addresses but don't deref mem, which the compiler might not be able to > follow in this case. > Great, thanks Daniel! > https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=6a12b8e20d7e72386594a9dbe7bf2d7fae3b3aa6 > > Thanks, > Daniel > > > Fixes: 1717e248014c ("selftests/bpf: Uprobe tests should verify param/return values") > > Signed-off-by: Artem Savkov <asavkov@xxxxxxxxxx> > > --- > > tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c b/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c > > index d6003dc8cc99..35b87c7ba5be 100644 > > --- a/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c > > +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c > > @@ -34,7 +34,6 @@ void test_uprobe_autoattach(void) > > > > /* trigger & validate shared library u[ret]probes attached by name */ > > mem = malloc(malloc_sz); > > - free(mem); > > > > ASSERT_EQ(skel->bss->uprobe_byname_parm1, trigger_val, "check_uprobe_byname_parm1"); > > ASSERT_EQ(skel->bss->uprobe_byname_ran, 1, "check_uprobe_byname_ran"); > > @@ -44,6 +43,8 @@ void test_uprobe_autoattach(void) > > ASSERT_EQ(skel->bss->uprobe_byname2_ran, 3, "check_uprobe_byname2_ran"); > > ASSERT_EQ(skel->bss->uretprobe_byname2_rc, mem, "check_uretprobe_byname2_rc"); > > ASSERT_EQ(skel->bss->uretprobe_byname2_ran, 4, "check_uretprobe_byname2_ran"); > > + > > + free(mem); > > cleanup: > > test_uprobe_autoattach__destroy(skel); > > } > > >
