2023-10-09 10:31:11

by Maciej Wieczor-Retman

[permalink] [raw]
Subject: [PATCH v4 0/8] Add printf attribute to kselftest functions

Kselftest.h declares many variadic functions that can print some
formatted message while also executing selftest logic. These
declarations don't have any compiler mechanism to verify if passed
arguments are valid in comparison with format specifiers used in
printf() calls.

Attribute addition can make debugging easier, the code more consistent
and prevent mismatched or missing variables.

Add a __printf() macro that validates types of variables passed to the
format string. The macro is similarly used in other tools in the kernel.

Add __printf() attributes to function definitions inside kselftest.h that
use printing.

Adding the __printf() macro exposes some mismatches in format strings
across different selftests.

Fix the mismatched format specifiers in multiple tests.

Series is based on kselftests next branch.

Changelog v4:
- Fix patch 1/8 subject typo.
- Add Reinette's reviewed-by tags.
- Rebased onto updated kselftests next branch.

Changelog v3:
- Changed git signature from Wieczor-Retman Maciej to Maciej
Wieczor-Retman.
- Added one review tag.
- Rebased onto updated kselftests next branch.

Changelog v2:
- Add review and fixes tags to patches.
- Add two patches with mismatch fixes.
- Fix missed attribute in selftests/kvm. (Andrew)
- Fix previously missed issues in selftests/mm (Ilpo)

[v3] https://lore.kernel.org/all/[email protected]/
[v2] https://lore.kernel.org/all/[email protected]/
[v1] https://lore.kernel.org/all/[email protected]/

Maciej Wieczor-Retman (8):
selftests: Add printf attribute to kselftest prints
selftests/cachestat: Fix print_cachestat format
selftests/openat2: Fix wrong format specifier
selftests/pidfd: Fix ksft print formats
selftests/sigaltstack: Fix wrong format specifier
selftests/kvm: Replace attribute with macro
selftests/mm: Substitute attribute with a macro
selftests/resctrl: Fix wrong format specifier

.../selftests/cachestat/test_cachestat.c | 2 +-
tools/testing/selftests/kselftest.h | 18 ++++++++++--------
.../testing/selftests/kvm/include/test_util.h | 8 ++++----
tools/testing/selftests/mm/mremap_test.c | 2 +-
tools/testing/selftests/mm/pkey-helpers.h | 2 +-
tools/testing/selftests/openat2/openat2_test.c | 2 +-
.../selftests/pidfd/pidfd_fdinfo_test.c | 2 +-
tools/testing/selftests/pidfd/pidfd_test.c | 12 ++++++------
tools/testing/selftests/resctrl/cache.c | 2 +-
tools/testing/selftests/sigaltstack/sas.c | 2 +-
10 files changed, 27 insertions(+), 25 deletions(-)


base-commit: f1020c687153609f246f3314db5b74821025c185
--
2.42.0


2023-10-09 10:31:36

by Maciej Wieczor-Retman

[permalink] [raw]
Subject: [PATCH v4 1/8] selftests: Add printf attribute to kselftest prints

Kselftest header defines multiple variadic functions that use printf
along with other logic.

There is no format checking for the variadic functions that use
printing inside kselftest.h. Because of this the compiler won't
be able to catch instances of mismatched printf formats and debugging
tests might be more difficult.

Add the common __printf attribute macro to kselftest.h.

Add __printf attribute to every function using formatted printing with
variadic arguments.

Signed-off-by: Maciej Wieczor-Retman <[email protected]>
Reviewed-by: Ilpo Järvinen <[email protected]>
Reviewed-by: Reinette Chatre <[email protected]>
---
Changelog v4:
- Fix typo in patch subject. (Reinette)
- Add Reinette's reviewed-by tag.

tools/testing/selftests/kselftest.h | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h
index af9f1202d423..5696199c16f9 100644
--- a/tools/testing/selftests/kselftest.h
+++ b/tools/testing/selftests/kselftest.h
@@ -78,6 +78,8 @@
#define KSFT_XPASS 3
#define KSFT_SKIP 4

+#define __printf(a, b) __attribute__((format(printf, a, b)))
+
/* counters */
struct ksft_count {
unsigned int ksft_pass;
@@ -144,7 +146,7 @@ static inline void ksft_print_cnts(void)
ksft_cnt.ksft_xskip, ksft_cnt.ksft_error);
}

-static inline void ksft_print_msg(const char *msg, ...)
+static inline __printf(1, 2) void ksft_print_msg(const char *msg, ...)
{
int saved_errno = errno;
va_list args;
@@ -169,7 +171,7 @@ static inline void ksft_perror(const char *msg)
#endif
}

-static inline void ksft_test_result_pass(const char *msg, ...)
+static inline __printf(1, 2) void ksft_test_result_pass(const char *msg, ...)
{
int saved_errno = errno;
va_list args;
@@ -183,7 +185,7 @@ static inline void ksft_test_result_pass(const char *msg, ...)
va_end(args);
}

-static inline void ksft_test_result_fail(const char *msg, ...)
+static inline __printf(1, 2) void ksft_test_result_fail(const char *msg, ...)
{
int saved_errno = errno;
va_list args;
@@ -209,7 +211,7 @@ static inline void ksft_test_result_fail(const char *msg, ...)
ksft_test_result_fail(fmt, ##__VA_ARGS__);\
} while (0)

-static inline void ksft_test_result_xfail(const char *msg, ...)
+static inline __printf(1, 2) void ksft_test_result_xfail(const char *msg, ...)
{
int saved_errno = errno;
va_list args;
@@ -223,7 +225,7 @@ static inline void ksft_test_result_xfail(const char *msg, ...)
va_end(args);
}

-static inline void ksft_test_result_skip(const char *msg, ...)
+static inline __printf(1, 2) void ksft_test_result_skip(const char *msg, ...)
{
int saved_errno = errno;
va_list args;
@@ -238,7 +240,7 @@ static inline void ksft_test_result_skip(const char *msg, ...)
}

/* TODO: how does "error" differ from "fail" or "skip"? */
-static inline void ksft_test_result_error(const char *msg, ...)
+static inline __printf(1, 2) void ksft_test_result_error(const char *msg, ...)
{
int saved_errno = errno;
va_list args;
@@ -285,7 +287,7 @@ static inline int ksft_exit_fail(void)
ksft_cnt.ksft_xfail + \
ksft_cnt.ksft_xskip)

-static inline int ksft_exit_fail_msg(const char *msg, ...)
+static inline __printf(1, 2) int ksft_exit_fail_msg(const char *msg, ...)
{
int saved_errno = errno;
va_list args;
@@ -312,7 +314,7 @@ static inline int ksft_exit_xpass(void)
exit(KSFT_XPASS);
}

-static inline int ksft_exit_skip(const char *msg, ...)
+static inline __printf(1, 2) int ksft_exit_skip(const char *msg, ...)
{
int saved_errno = errno;
va_list args;
--
2.42.0

2023-10-09 10:31:41

by Maciej Wieczor-Retman

[permalink] [raw]
Subject: [PATCH v4 2/8] selftests/cachestat: Fix print_cachestat format

The format specifier in printf() call expects long int variables and
received long long int.

Change format specifiers to long long int so they match passed
variables.

Signed-off-by: Maciej Wieczor-Retman <[email protected]>
Acked-by: Nhat Pham <[email protected]>
---
Changelog v2:
- Added Acked-by tag (Nhat)

tools/testing/selftests/cachestat/test_cachestat.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/cachestat/test_cachestat.c b/tools/testing/selftests/cachestat/test_cachestat.c
index 4804c7dc7b31..b171fd53b004 100644
--- a/tools/testing/selftests/cachestat/test_cachestat.c
+++ b/tools/testing/selftests/cachestat/test_cachestat.c
@@ -27,7 +27,7 @@ static const char * const dev_files[] = {
void print_cachestat(struct cachestat *cs)
{
ksft_print_msg(
- "Using cachestat: Cached: %lu, Dirty: %lu, Writeback: %lu, Evicted: %lu, Recently Evicted: %lu\n",
+ "Using cachestat: Cached: %llu, Dirty: %llu, Writeback: %llu, Evicted: %llu, Recently Evicted: %llu\n",
cs->nr_cache, cs->nr_dirty, cs->nr_writeback,
cs->nr_evicted, cs->nr_recently_evicted);
}
--
2.42.0

2023-10-09 10:31:44

by Maciej Wieczor-Retman

[permalink] [raw]
Subject: [PATCH v4 3/8] selftests/openat2: Fix wrong format specifier

Ksft_print_msg() inside test_openat2_flags() uses the wrong format
specifier for printing test.how->flags variable.

Change the format specifier to %llX so it matches the printed variable.

Signed-off-by: Maciej Wieczor-Retman <[email protected]>
Reviewed-by: Ilpo Järvinen <[email protected]>
---
Changelog v2:
- Added Reviewed-by tag (Ilpo)

tools/testing/selftests/openat2/openat2_test.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/openat2/openat2_test.c b/tools/testing/selftests/openat2/openat2_test.c
index 7fb902099de4..9024754530b2 100644
--- a/tools/testing/selftests/openat2/openat2_test.c
+++ b/tools/testing/selftests/openat2/openat2_test.c
@@ -300,7 +300,7 @@ void test_openat2_flags(void)

ksft_print_msg("openat2 unexpectedly returned ");
if (fdpath)
- ksft_print_msg("%d['%s'] with %X (!= %X)\n",
+ ksft_print_msg("%d['%s'] with %X (!= %llX)\n",
fd, fdpath, fdflags,
test->how.flags);
else
--
2.42.0

2023-10-09 10:31:59

by Maciej Wieczor-Retman

[permalink] [raw]
Subject: [PATCH v4 4/8] selftests/pidfd: Fix ksft print formats

Many calls to ksft print functions have format strings that don't match
with other passed arguments. One call expects a string but doesn't
provide any argument after the format string.

Fix format specifiers so they match the passed variables.

Add a missing variable to ksft_test_result_pass() inside
pidfd_fdinfo_test() so it matches other cases in the switch statement.

Fixes: 2def297ec7fb ("pidfd: add tests for NSpid info in fdinfo")

Signed-off-by: Maciej Wieczor-Retman <[email protected]>
---
Changelog v2:
- Add fixes tag to patch message.

tools/testing/selftests/pidfd/pidfd_fdinfo_test.c | 2 +-
tools/testing/selftests/pidfd/pidfd_test.c | 12 ++++++------
2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c b/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c
index 4e86f927880c..01cc37bf611c 100644
--- a/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c
@@ -62,7 +62,7 @@ static void error_report(struct error *err, const char *test_name)
break;

case PIDFD_PASS:
- ksft_test_result_pass("%s test: Passed\n");
+ ksft_test_result_pass("%s test: Passed\n", test_name);
break;

default:
diff --git a/tools/testing/selftests/pidfd/pidfd_test.c b/tools/testing/selftests/pidfd/pidfd_test.c
index 00a07e7c571c..c081ae91313a 100644
--- a/tools/testing/selftests/pidfd/pidfd_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_test.c
@@ -381,13 +381,13 @@ static int test_pidfd_send_signal_syscall_support(void)

static void *test_pidfd_poll_exec_thread(void *priv)
{
- ksft_print_msg("Child Thread: starting. pid %d tid %d ; and sleeping\n",
+ ksft_print_msg("Child Thread: starting. pid %d tid %ld ; and sleeping\n",
getpid(), syscall(SYS_gettid));
ksft_print_msg("Child Thread: doing exec of sleep\n");

execl("/bin/sleep", "sleep", str(CHILD_THREAD_MIN_WAIT), (char *)NULL);

- ksft_print_msg("Child Thread: DONE. pid %d tid %d\n",
+ ksft_print_msg("Child Thread: DONE. pid %d tid %ld\n",
getpid(), syscall(SYS_gettid));
return NULL;
}
@@ -427,7 +427,7 @@ static int child_poll_exec_test(void *args)
{
pthread_t t1;

- ksft_print_msg("Child (pidfd): starting. pid %d tid %d\n", getpid(),
+ ksft_print_msg("Child (pidfd): starting. pid %d tid %ld\n", getpid(),
syscall(SYS_gettid));
pthread_create(&t1, NULL, test_pidfd_poll_exec_thread, NULL);
/*
@@ -480,10 +480,10 @@ static void test_pidfd_poll_exec(int use_waitpid)

static void *test_pidfd_poll_leader_exit_thread(void *priv)
{
- ksft_print_msg("Child Thread: starting. pid %d tid %d ; and sleeping\n",
+ ksft_print_msg("Child Thread: starting. pid %d tid %ld ; and sleeping\n",
getpid(), syscall(SYS_gettid));
sleep(CHILD_THREAD_MIN_WAIT);
- ksft_print_msg("Child Thread: DONE. pid %d tid %d\n", getpid(), syscall(SYS_gettid));
+ ksft_print_msg("Child Thread: DONE. pid %d tid %ld\n", getpid(), syscall(SYS_gettid));
return NULL;
}

@@ -492,7 +492,7 @@ static int child_poll_leader_exit_test(void *args)
{
pthread_t t1, t2;

- ksft_print_msg("Child: starting. pid %d tid %d\n", getpid(), syscall(SYS_gettid));
+ ksft_print_msg("Child: starting. pid %d tid %ld\n", getpid(), syscall(SYS_gettid));
pthread_create(&t1, NULL, test_pidfd_poll_leader_exit_thread, NULL);
pthread_create(&t2, NULL, test_pidfd_poll_leader_exit_thread, NULL);

--
2.42.0

2023-10-09 10:32:03

by Maciej Wieczor-Retman

[permalink] [raw]
Subject: [PATCH v4 5/8] selftests/sigaltstack: Fix wrong format specifier

The format specifier inside ksft printing function expects a long
unsigned int but the passed variable is of unsigned int type.

Fix the format specifier so it matches the passed variable.

Signed-off-by: Maciej Wieczor-Retman <[email protected]>
Reviewed-by: Ilpo Järvinen <[email protected]>
---
Changelog v2:
- Added Reviewed-by tag (Ilpo)

tools/testing/selftests/sigaltstack/sas.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/sigaltstack/sas.c b/tools/testing/selftests/sigaltstack/sas.c
index 98d37cb744fb..07227fab1cc9 100644
--- a/tools/testing/selftests/sigaltstack/sas.c
+++ b/tools/testing/selftests/sigaltstack/sas.c
@@ -111,7 +111,7 @@ int main(void)

/* Make sure more than the required minimum. */
stack_size = getauxval(AT_MINSIGSTKSZ) + SIGSTKSZ;
- ksft_print_msg("[NOTE]\tthe stack size is %lu\n", stack_size);
+ ksft_print_msg("[NOTE]\tthe stack size is %u\n", stack_size);

ksft_print_header();
ksft_set_plan(3);
--
2.42.0

2023-10-09 10:32:12

by Maciej Wieczor-Retman

[permalink] [raw]
Subject: [PATCH v4 8/8] selftests/resctrl: Fix wrong format specifier

A long unsigned int variable is passed to the ksft_print_msg() and the
format specifier used expects a variable of type int.

Change the format specifier to match the passed variable.

Signed-off-by: Maciej Wieczor-Retman <[email protected]>
Reviewed-by: Ilpo Järvinen <[email protected]>
Reviewed-by: Reinette Chatre <[email protected]>
---
Changelog v4:
- Added Reinette's reviewed-by tag.

Changelog v3:
- Added Ilpo's reviewed-by tag.

Changelog v2:
- Added this patch to the series.

tools/testing/selftests/resctrl/cache.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/resctrl/cache.c b/tools/testing/selftests/resctrl/cache.c
index d3cbb829ff6a..a5d082cd2d53 100644
--- a/tools/testing/selftests/resctrl/cache.c
+++ b/tools/testing/selftests/resctrl/cache.c
@@ -294,7 +294,7 @@ int show_cache_info(unsigned long sum_llc_val, int no_of_bits,
ret = platform && abs((int)diff_percent) > max_diff_percent &&
(cmt ? (abs(avg_diff) > max_diff) : true);

- ksft_print_msg("%s Check cache miss rate within %d%%\n",
+ ksft_print_msg("%s Check cache miss rate within %lu%%\n",
ret ? "Fail:" : "Pass:", max_diff_percent);

ksft_print_msg("Percent diff=%d\n", abs((int)diff_percent));
--
2.42.0

2023-10-09 10:32:19

by Maciej Wieczor-Retman

[permalink] [raw]
Subject: [PATCH v4 6/8] selftests/kvm: Replace attribute with macro

The __printf() macro is used in many tools in the linux kernel to
validate the format specifiers in functions that use printf. The kvm
selftest uses it without putting it in a macro definition while it
also imports the kselftests.h header.

Use __printf() from kselftests.h instead of the full attribute.

Signed-off-by: Maciej Wieczor-Retman <[email protected]>
---
Changelog v2:
- Reword patch message.
- Use __printf() on test_assert().

tools/testing/selftests/kvm/include/test_util.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h
index 7e614adc6cf4..8e5f413a593d 100644
--- a/tools/testing/selftests/kvm/include/test_util.h
+++ b/tools/testing/selftests/kvm/include/test_util.h
@@ -33,7 +33,7 @@ static inline int _no_printf(const char *format, ...) { return 0; }
#define pr_info(...) _no_printf(__VA_ARGS__)
#endif

-void print_skip(const char *fmt, ...) __attribute__((format(printf, 1, 2)));
+void __printf(1, 2) print_skip(const char *fmt, ...);
#define __TEST_REQUIRE(f, fmt, ...) \
do { \
if (!(f)) \
@@ -46,9 +46,9 @@ ssize_t test_write(int fd, const void *buf, size_t count);
ssize_t test_read(int fd, void *buf, size_t count);
int test_seq_read(const char *path, char **bufp, size_t *sizep);

-void test_assert(bool exp, const char *exp_str,
- const char *file, unsigned int line, const char *fmt, ...)
- __attribute__((format(printf, 5, 6)));
+void __printf(5, 6) test_assert(bool exp, const char *exp_str,
+ const char *file, unsigned int line,
+ const char *fmt, ...);

#define TEST_ASSERT(e, fmt, ...) \
test_assert((e), #e, __FILE__, __LINE__, fmt, ##__VA_ARGS__)
--
2.42.0

2023-10-09 10:32:28

by Maciej Wieczor-Retman

[permalink] [raw]
Subject: [PATCH v4 7/8] selftests/mm: Substitute attribute with a macro

The mm selftest uses the printf attribute in its full form. Since the
header file that uses it also includes kselftests.h it can use the macro
defined there.

Use __printf() included with kselftests.h instead of the full attribute.

Fix a wrong format specifier in ksft_print_msg().

Signed-off-by: Maciej Wieczor-Retman <[email protected]>
---
Changelog v2:
- Added this patch to the series.

tools/testing/selftests/mm/mremap_test.c | 2 +-
tools/testing/selftests/mm/pkey-helpers.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/mm/mremap_test.c b/tools/testing/selftests/mm/mremap_test.c
index 5c3773de9f0f..1dbfcf6df255 100644
--- a/tools/testing/selftests/mm/mremap_test.c
+++ b/tools/testing/selftests/mm/mremap_test.c
@@ -338,7 +338,7 @@ static long long remap_region(struct config c, unsigned int threshold_mb,
char c = (char) rand();

if (((char *) dest_addr)[i] != c) {
- ksft_print_msg("Data after remap doesn't match at offset %d\n",
+ ksft_print_msg("Data after remap doesn't match at offset %llu\n",
i);
ksft_print_msg("Expected: %#x\t Got: %#x\n", c & 0xff,
((char *) dest_addr)[i] & 0xff);
diff --git a/tools/testing/selftests/mm/pkey-helpers.h b/tools/testing/selftests/mm/pkey-helpers.h
index 92f3be3dd8e5..1af3156a9db8 100644
--- a/tools/testing/selftests/mm/pkey-helpers.h
+++ b/tools/testing/selftests/mm/pkey-helpers.h
@@ -34,7 +34,7 @@ extern int test_nr;
extern int iteration_nr;

#ifdef __GNUC__
-__attribute__((format(printf, 1, 2)))
+__printf(1, 2)
#endif
static inline void sigsafe_printf(const char *format, ...)
{
--
2.42.0

2023-10-09 17:28:56

by Shuah Khan

[permalink] [raw]
Subject: Re: [PATCH v4 0/8] Add printf attribute to kselftest functions

On 10/9/23 04:28, Maciej Wieczor-Retman wrote:
> Kselftest.h declares many variadic functions that can print some
> formatted message while also executing selftest logic. These
> declarations don't have any compiler mechanism to verify if passed
> arguments are valid in comparison with format specifiers used in
> printf() calls.
>
> Attribute addition can make debugging easier, the code more consistent
> and prevent mismatched or missing variables.
>
> Add a __printf() macro that validates types of variables passed to the
> format string. The macro is similarly used in other tools in the kernel.
>
> Add __printf() attributes to function definitions inside kselftest.h that
> use printing.
>
> Adding the __printf() macro exposes some mismatches in format strings
> across different selftests.
>
> Fix the mismatched format specifiers in multiple tests.
>
> Series is based on kselftests next branch.

How did you find these problems? I don't see any information
how these problems are found in the commit logs.

thanks,
-- Shuah

2023-10-10 05:53:56

by Maciej Wieczor-Retman

[permalink] [raw]
Subject: Re: [PATCH v4 0/8] Add printf attribute to kselftest functions

On 2023-10-09 at 11:28:30 -0600, Shuah Khan wrote:
>On 10/9/23 04:28, Maciej Wieczor-Retman wrote:
>> Kselftest.h declares many variadic functions that can print some
>> formatted message while also executing selftest logic. These
>> declarations don't have any compiler mechanism to verify if passed
>> arguments are valid in comparison with format specifiers used in
>> printf() calls.
>>
>> Attribute addition can make debugging easier, the code more consistent
>> and prevent mismatched or missing variables.
>>
>> Add a __printf() macro that validates types of variables passed to the
>> format string. The macro is similarly used in other tools in the kernel.
>>
>> Add __printf() attributes to function definitions inside kselftest.h that
>> use printing.
>>
>> Adding the __printf() macro exposes some mismatches in format strings
>> across different selftests.
>>
>> Fix the mismatched format specifiers in multiple tests.
>>
>> Series is based on kselftests next branch.
>
>How did you find these problems? I don't see any information
>how these problems are found in the commit logs.
>
>thanks,
>-- Shuah

I wrote the first patch that adds the check to functions with format
specifiers and I compiled all selftests. Then I just corrected any
warnings that were found by the __printf attribute.

Should I mention the methodology in the cover letter?

--
Kind regards
Maciej Wiecz?r-Retman