| Message ID | 20211006002853.308945-6-memxor@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | BPF |
| Headers | show |
| Series | Typeless/weak ksym for gen_loader + misc fixups | expand |
On Wed, Oct 06, 2021 at 02:28 AM CEST, Kumar Kartikeya Dwivedi wrote: > Similar to the fix in commit: > e31eec77e4ab (bpf: selftests: Fix fd cleanup in get_branch_snapshot) > > We use memset to set fds to -1 without breaking on future changes to > the array size (when MAX_SERVER constant is bumped). > > The particular close(0) occurs on non-reuseport tests, so it can be seen > with -n 115/{2,3} but not 115/4. This can cause problems with future > tests if they depend on BTF fd never being acquired as fd 0, breaking > internal libbpf assumptions. > > Cc: Jakub Sitnicki <jakub@cloudflare.com> > Fixes: 0ab5539f8584 (selftests/bpf: Tests for BPF_SK_LOOKUP attach point) > Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> > --- > .../selftests/bpf/prog_tests/sk_lookup.c | 20 +++++++++++++------ > 1 file changed, 14 insertions(+), 6 deletions(-) > > diff --git a/tools/testing/selftests/bpf/prog_tests/sk_lookup.c b/tools/testing/selftests/bpf/prog_tests/sk_lookup.c > index aee41547e7f4..572220065bdf 100644 > --- a/tools/testing/selftests/bpf/prog_tests/sk_lookup.c > +++ b/tools/testing/selftests/bpf/prog_tests/sk_lookup.c > @@ -598,11 +598,14 @@ static void query_lookup_prog(struct test_sk_lookup *skel) > > static void run_lookup_prog(const struct test *t) > { > - int server_fds[MAX_SERVERS] = { -1 }; > int client_fd, reuse_conn_fd = -1; > struct bpf_link *lookup_link; > + int server_fds[MAX_SERVERS]; > int i, err; > > + /* set all fds to -1 */ > + memset(server_fds, 0xFF, sizeof(server_fds)); > + > lookup_link = attach_lookup_prog(t->lookup_prog); > if (!lookup_link) > return; > @@ -663,8 +666,9 @@ static void run_lookup_prog(const struct test *t) > if (reuse_conn_fd != -1) > close(reuse_conn_fd); > for (i = 0; i < ARRAY_SIZE(server_fds); i++) { > - if (server_fds[i] != -1) > - close(server_fds[i]); > + if (server_fds[i] == -1) > + break; > + close(server_fds[i]); > } > bpf_link__destroy(lookup_link); > } > @@ -1053,11 +1057,14 @@ static void run_sk_assign(struct test_sk_lookup *skel, > struct bpf_program *lookup_prog, > const char *remote_ip, const char *local_ip) > { > - int server_fds[MAX_SERVERS] = { -1 }; > + int server_fds[MAX_SERVERS]; > struct bpf_sk_lookup ctx; > __u64 server_cookie; > int i, err; > > + /* set all fds to -1 */ > + memset(server_fds, 0xFF, sizeof(server_fds)); > + > DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts, > .ctx_in = &ctx, > .ctx_size_in = sizeof(ctx), > @@ -1097,8 +1104,9 @@ static void run_sk_assign(struct test_sk_lookup *skel, > > close_servers: > for (i = 0; i < ARRAY_SIZE(server_fds); i++) { > - if (server_fds[i] != -1) > - close(server_fds[i]); > + if (server_fds[i] == -1) > + break; > + close(server_fds[i]); > } > } My mistake. Thanks for the fix. Alternatively we can use an extended designated initializer: int server_fds[] = { [0 ... MAX_SERVERS] = -1 }; Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
On Tue, Oct 5, 2021 at 11:50 PM Jakub Sitnicki <jakub@cloudflare.com> wrote: > > On Wed, Oct 06, 2021 at 02:28 AM CEST, Kumar Kartikeya Dwivedi wrote: > > Similar to the fix in commit: > > e31eec77e4ab (bpf: selftests: Fix fd cleanup in get_branch_snapshot) > > > > We use memset to set fds to -1 without breaking on future changes to > > the array size (when MAX_SERVER constant is bumped). > > > > The particular close(0) occurs on non-reuseport tests, so it can be seen > > with -n 115/{2,3} but not 115/4. This can cause problems with future > > tests if they depend on BTF fd never being acquired as fd 0, breaking > > internal libbpf assumptions. > > > > Cc: Jakub Sitnicki <jakub@cloudflare.com> > > Fixes: 0ab5539f8584 (selftests/bpf: Tests for BPF_SK_LOOKUP attach point) Similar to Andrii's comment in 6/6, we need add " to the Fixes tag. > > Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Acked-by: Song Liu <songliubraving@fb.com> > > Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
diff --git a/tools/testing/selftests/bpf/prog_tests/sk_lookup.c b/tools/testing/selftests/bpf/prog_tests/sk_lookup.c index aee41547e7f4..572220065bdf 100644 --- a/tools/testing/selftests/bpf/prog_tests/sk_lookup.c +++ b/tools/testing/selftests/bpf/prog_tests/sk_lookup.c @@ -598,11 +598,14 @@ static void query_lookup_prog(struct test_sk_lookup *skel) static void run_lookup_prog(const struct test *t) { - int server_fds[MAX_SERVERS] = { -1 }; int client_fd, reuse_conn_fd = -1; struct bpf_link *lookup_link; + int server_fds[MAX_SERVERS]; int i, err; + /* set all fds to -1 */ + memset(server_fds, 0xFF, sizeof(server_fds)); + lookup_link = attach_lookup_prog(t->lookup_prog); if (!lookup_link) return; @@ -663,8 +666,9 @@ static void run_lookup_prog(const struct test *t) if (reuse_conn_fd != -1) close(reuse_conn_fd); for (i = 0; i < ARRAY_SIZE(server_fds); i++) { - if (server_fds[i] != -1) - close(server_fds[i]); + if (server_fds[i] == -1) + break; + close(server_fds[i]); } bpf_link__destroy(lookup_link); } @@ -1053,11 +1057,14 @@ static void run_sk_assign(struct test_sk_lookup *skel, struct bpf_program *lookup_prog, const char *remote_ip, const char *local_ip) { - int server_fds[MAX_SERVERS] = { -1 }; + int server_fds[MAX_SERVERS]; struct bpf_sk_lookup ctx; __u64 server_cookie; int i, err; + /* set all fds to -1 */ + memset(server_fds, 0xFF, sizeof(server_fds)); + DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts, .ctx_in = &ctx, .ctx_size_in = sizeof(ctx), @@ -1097,8 +1104,9 @@ static void run_sk_assign(struct test_sk_lookup *skel, close_servers: for (i = 0; i < ARRAY_SIZE(server_fds); i++) { - if (server_fds[i] != -1) - close(server_fds[i]); + if (server_fds[i] == -1) + break; + close(server_fds[i]); } }
Similar to the fix in commit: e31eec77e4ab (bpf: selftests: Fix fd cleanup in get_branch_snapshot) We use memset to set fds to -1 without breaking on future changes to the array size (when MAX_SERVER constant is bumped). The particular close(0) occurs on non-reuseport tests, so it can be seen with -n 115/{2,3} but not 115/4. This can cause problems with future tests if they depend on BTF fd never being acquired as fd 0, breaking internal libbpf assumptions. Cc: Jakub Sitnicki <jakub@cloudflare.com> Fixes: 0ab5539f8584 (selftests/bpf: Tests for BPF_SK_LOOKUP attach point) Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> --- .../selftests/bpf/prog_tests/sk_lookup.c | 20 +++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-)