From: Ihor Solodrai <ihor.solodrai@linux.dev>
To: Eduard Zingerman <eddyz87@gmail.com>,
bpf@vger.kernel.org, ast@kernel.org, andrii@kernel.org
Cc: daniel@iogearbox.net, martin.lau@linux.dev, kernel-team@fb.com,
yonghong.song@linux.dev, cupertino.miranda@oracle.com
Subject: Re: [PATCH 2/4] selftests/bpf: make str_has_pfx return pointer past the prefix
Date: Fri, 27 Mar 2026 14:54:18 -0700 [thread overview]
Message-ID: <e3db8a52-e526-403f-9eaa-215e4f364bb7@linux.dev> (raw)
In-Reply-To: <20260326-selftests-global-tags-ordering-v1-2-5dd2ced5d9ad@gmail.com>
On 3/26/26 10:39 AM, Eduard Zingerman wrote:
> Change str_has_pfx() to return a pointer to the first character after
> the prefix, thus eliminating the repetitive (s + sizeof(PFX) - 1)
> patterns.
>
> Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
> ---
> tools/testing/selftests/bpf/test_loader.c | 41 ++++++++++++++-----------------
> 1 file changed, 18 insertions(+), 23 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/test_loader.c b/tools/testing/selftests/bpf/test_loader.c
> index 338c035c36884c02ac57cd17110122c10b4858e4..f1eb99f829e112f0e738bfe44e7e61a49120ec85 100644
> --- a/tools/testing/selftests/bpf/test_loader.c
> +++ b/tools/testing/selftests/bpf/test_loader.c
> @@ -11,8 +11,12 @@
> #include "cap_helpers.h"
> #include "jit_disasm_helpers.h"
>
> -#define str_has_pfx(str, pfx) \
> - (strncmp(str, pfx, __builtin_constant_p(pfx) ? sizeof(pfx) - 1 : strlen(pfx)) == 0)
> +static inline const char *str_has_pfx(const char *str, const char *pfx)
> +{
> + size_t len = strlen(pfx);
> +
> + return strncmp(str, pfx, len) == 0 ? str + len : NULL;
> +}
>
> #define TEST_LOADER_LOG_BUF_SZ 2097152
>
> @@ -452,8 +456,8 @@ static int parse_test_spec(struct test_loader *tester,
> continue;
>
> s = btf__str_by_offset(btf, t->name_off);
> - if (str_has_pfx(s, TEST_TAG_DESCRIPTION_PFX)) {
> - description = s + sizeof(TEST_TAG_DESCRIPTION_PFX) - 1;
> + if ((val = str_has_pfx(s, TEST_TAG_DESCRIPTION_PFX))) {
Personally, I don't like assignments in the if expressions.
For example, this is annoying when you are stepping in the debugger.
But who does that in 2026, right?..
Acked-by: Ihor Solodrai <ihor.solodrai@linux.dev>
> + description = val;
> } else if (strcmp(s, TEST_TAG_EXPECT_FAILURE) == 0) {
> spec->priv.expect_failure = true;
> spec->mode_mask |= PRIV;
> @@ -530,29 +534,24 @@ static int parse_test_spec(struct test_loader *tester,
> if (err)
> goto cleanup;
> spec->mode_mask |= UNPRIV;
> - } else if (str_has_pfx(s, TEST_TAG_RETVAL_PFX)) {
> - val = s + sizeof(TEST_TAG_RETVAL_PFX) - 1;
> + } else if ((val = str_has_pfx(s, TEST_TAG_RETVAL_PFX))) {
> err = parse_retval(val, &spec->priv.retval, "__retval");
> if (err)
> goto cleanup;
> spec->priv.execute = true;
> spec->mode_mask |= PRIV;
> - } else if (str_has_pfx(s, TEST_TAG_RETVAL_PFX_UNPRIV)) {
> - val = s + sizeof(TEST_TAG_RETVAL_PFX_UNPRIV) - 1;
> + } else if ((val = str_has_pfx(s, TEST_TAG_RETVAL_PFX_UNPRIV))) {
> err = parse_retval(val, &spec->unpriv.retval, "__retval_unpriv");
> if (err)
> goto cleanup;
> spec->mode_mask |= UNPRIV;
> spec->unpriv.execute = true;
> has_unpriv_retval = true;
> - } else if (str_has_pfx(s, TEST_TAG_LOG_LEVEL_PFX)) {
> - val = s + sizeof(TEST_TAG_LOG_LEVEL_PFX) - 1;
> + } else if ((val = str_has_pfx(s, TEST_TAG_LOG_LEVEL_PFX))) {
> err = parse_int(val, &spec->log_level, "test log level");
> if (err)
> goto cleanup;
> - } else if (str_has_pfx(s, TEST_TAG_PROG_FLAGS_PFX)) {
> - val = s + sizeof(TEST_TAG_PROG_FLAGS_PFX) - 1;
> -
> + } else if ((val = str_has_pfx(s, TEST_TAG_PROG_FLAGS_PFX))) {
> clear = val[0] == '!';
> if (clear)
> val++;
> @@ -577,8 +576,7 @@ static int parse_test_spec(struct test_loader *tester,
> goto cleanup;
> update_flags(&spec->prog_flags, flags, clear);
> }
> - } else if (str_has_pfx(s, TEST_TAG_ARCH)) {
> - val = s + sizeof(TEST_TAG_ARCH) - 1;
> + } else if ((val = str_has_pfx(s, TEST_TAG_ARCH))) {
> if (strcmp(val, "X86_64") == 0) {
> arch = ARCH_X86_64;
> } else if (strcmp(val, "ARM64") == 0) {
> @@ -596,16 +594,14 @@ static int parse_test_spec(struct test_loader *tester,
> collect_jit = get_current_arch() == arch;
> unpriv_jit_on_next_line = true;
> jit_on_next_line = true;
> - } else if (str_has_pfx(s, TEST_BTF_PATH)) {
> - spec->btf_custom_path = s + sizeof(TEST_BTF_PATH) - 1;
> - } else if (str_has_pfx(s, TEST_TAG_CAPS_UNPRIV)) {
> - val = s + sizeof(TEST_TAG_CAPS_UNPRIV) - 1;
> + } else if ((val = str_has_pfx(s, TEST_BTF_PATH))) {
> + spec->btf_custom_path = val;
> + } else if ((val = str_has_pfx(s, TEST_TAG_CAPS_UNPRIV))) {
> err = parse_caps(val, &spec->unpriv.caps, "test caps");
> if (err)
> goto cleanup;
> spec->mode_mask |= UNPRIV;
> - } else if (str_has_pfx(s, TEST_TAG_LOAD_MODE_PFX)) {
> - val = s + sizeof(TEST_TAG_LOAD_MODE_PFX) - 1;
> + } else if ((val = str_has_pfx(s, TEST_TAG_LOAD_MODE_PFX))) {
> if (strcmp(val, "jited") == 0) {
> load_mask = JITED;
> } else if (strcmp(val, "no_jited") == 0) {
> @@ -635,12 +631,11 @@ static int parse_test_spec(struct test_loader *tester,
> &spec->unpriv.stdout);
> if (err)
> goto cleanup;
> - } else if (str_has_pfx(s, TEST_TAG_LINEAR_SIZE)) {
> + } else if ((val = str_has_pfx(s, TEST_TAG_LINEAR_SIZE))) {
> switch (bpf_program__type(prog)) {
> case BPF_PROG_TYPE_SCHED_ACT:
> case BPF_PROG_TYPE_SCHED_CLS:
> case BPF_PROG_TYPE_CGROUP_SKB:
> - val = s + sizeof(TEST_TAG_LINEAR_SIZE) - 1;
> err = parse_int(val, &spec->linear_sz, "test linear size");
> if (err)
> goto cleanup;
>
next prev parent reply other threads:[~2026-03-27 21:54 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-26 17:39 [PATCH 0/4] selftests/bpf: impose global ordering for test decl_tags Eduard Zingerman
2026-03-26 17:39 ` [PATCH 1/4] selftests/bpf: fix __jited_unpriv tag name Eduard Zingerman
2026-03-27 21:52 ` Ihor Solodrai
2026-03-26 17:39 ` [PATCH 2/4] selftests/bpf: make str_has_pfx return pointer past the prefix Eduard Zingerman
2026-03-27 21:54 ` Ihor Solodrai [this message]
2026-03-27 21:57 ` Eduard Zingerman
2026-03-26 17:39 ` [PATCH 3/4] selftests/bpf: impose global ordering for test decl_tags Eduard Zingerman
2026-03-26 22:47 ` Andrii Nakryiko
2026-03-26 22:51 ` Eduard Zingerman
2026-03-26 23:00 ` Andrii Nakryiko
2026-03-26 23:30 ` Eduard Zingerman
2026-03-27 22:00 ` Ihor Solodrai
2026-03-27 22:07 ` Eduard Zingerman
2026-03-26 17:39 ` [PATCH 4/4] selftests/bpf: inline TEST_TAG constants in test_loader.c Eduard Zingerman
2026-03-27 22:04 ` Ihor Solodrai
2026-03-26 22:28 ` [PATCH 0/4] selftests/bpf: impose global ordering for test decl_tags Eduard Zingerman
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