After commit 6d029c25b71f ("selftests/timers/posix_timers: Reimplement check_timer_distribution()") I started seeing the following warning building with an older gcc:
posix_timers.c:250:2: warning: format not a string literal and no format arguments [-Wformat-security] 250 | ksft_print_msg(errmsg); | ^~~~~~~~~~~~~~
Fix this up by changing it to ksft_print_msg("%s", errmsg)
Cc: Shuah Khan shuah@kernel.org Cc: Anna-Maria Behnsen anna-maria@linutronix.de Cc: Frederic Weisbecker frederic@kernel.org Cc: Thomas Gleixner tglx@linutronix.de Cc: Stephen Boyd sboyd@kernel.org Cc: Nathan Chancellor nathan@kernel.org Cc: Nick Desaulniers ndesaulniers@google.com Cc: Bill Wendling morbo@google.com Cc: Justin Stitt justinstitt@google.com Cc: Oleg Nesterov oleg@redhat.com Cc: Andrew Morton akpm@linux-foundation.org Cc: Edward Liaw edliaw@google.com Cc: Carlos Llamas cmllamas@google.com Cc: kernel-team@android.com Cc: linux-kselftest@vger.kernel.org Fixes: 6d029c25b71f ("selftests/timers/posix_timers: Reimplement check_timer_distribution()") Signed-off-by: John Stultz jstultz@google.com --- tools/testing/selftests/timers/posix_timers.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c index d86a0e00711e..348f47176e0a 100644 --- a/tools/testing/selftests/timers/posix_timers.c +++ b/tools/testing/selftests/timers/posix_timers.c @@ -247,7 +247,7 @@ static int check_timer_distribution(void) ksft_test_result_skip("check signal distribution (old kernel)\n"); return 0; err: - ksft_print_msg(errmsg); + ksft_print_msg("%s", errmsg); return -1; }
Building with clang, I see the following warning:
In file included from posix_timers.c:17: ./../kselftest.h:398:6: warning: variable 'major' is used uninitialized whenever '||' condition is true [-Wsometimes-uninitialized] if (uname(&info) || sscanf(info.release, "%u.%u.", &major, &minor) != 2) ^~~~~~~~~~~~ ./../kselftest.h:401:9: note: uninitialized use occurs here return major > min_major || (major == min_major && minor >= min_minor); ^~~~~
This is a bit of a red-herring as if the uname() call did fail, we would hit ksft_exit_fail_msg() which should exit.
But to make clang happpy, lets initialize the major/minor values to zero.
Cc: Shuah Khan shuah@kernel.org Cc: Anna-Maria Behnsen anna-maria@linutronix.de Cc: Frederic Weisbecker frederic@kernel.org Cc: Thomas Gleixner tglx@linutronix.de Cc: Stephen Boyd sboyd@kernel.org Cc: Nathan Chancellor nathan@kernel.org Cc: Nick Desaulniers ndesaulniers@google.com Cc: Bill Wendling morbo@google.com Cc: Justin Stitt justinstitt@google.com Cc: Oleg Nesterov oleg@redhat.com Cc: Andrew Morton akpm@linux-foundation.org Cc: Edward Liaw edliaw@google.com Cc: Carlos Llamas cmllamas@google.com Cc: kernel-team@android.com Cc: linux-kselftest@vger.kernel.org Fixes: 6d029c25b71f ("selftests/timers/posix_timers: Reimplement check_timer_distribution()") Signed-off-by: John Stultz jstultz@google.com --- tools/testing/selftests/kselftest.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h index 973b18e156b2..12e2f3ab8b13 100644 --- a/tools/testing/selftests/kselftest.h +++ b/tools/testing/selftests/kselftest.h @@ -392,7 +392,7 @@ static inline __printf(1, 2) int ksft_exit_skip(const char *msg, ...) static inline int ksft_min_kernel_version(unsigned int min_major, unsigned int min_minor) { - unsigned int major, minor; + unsigned int major = 0, minor = 0; struct utsname info;
if (uname(&info) || sscanf(info.release, "%u.%u.", &major, &minor) != 2)
On Wed, Apr 10, 2024 at 04:26:29PM -0700, John Stultz wrote:
Building with clang, I see the following warning:
In file included from posix_timers.c:17: ./../kselftest.h:398:6: warning: variable 'major' is used uninitialized whenever '||' condition is true [-Wsometimes-uninitialized] if (uname(&info) || sscanf(info.release, "%u.%u.", &major, &minor) != 2) ^~~~~~~~~~~~ ./../kselftest.h:401:9: note: uninitialized use occurs here return major > min_major || (major == min_major && minor >= min_minor); ^~~~~
This is a bit of a red-herring as if the uname() call did fail, we would hit ksft_exit_fail_msg() which should exit.
Correct, although we have not really conveyed that to the compiler, right? exit() is noreturn, which means all functions that call exit() unconditionally are also noreturn, such as ksft_exit_fail_msg(). LLVM will figure this out once it performs inlining and such but that happens after clang's static analysis phase that this warning occurs in. I think a better solution would be to add __noreturn to the functions in tools/testing/selftests/kselftest.h that call exit(), so that the compiler is aware of this through all pipeline phases, maybe something like this? It resolves the wawrning for me.
diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h index 050c5fd01840..29364c9f3332 100644 --- a/tools/testing/selftests/kselftest.h +++ b/tools/testing/selftests/kselftest.h @@ -83,6 +83,7 @@ #define KSFT_XPASS 3 #define KSFT_SKIP 4
+#define __noreturn __attribute__((__noreturn__)) #define __printf(a, b) __attribute__((format(printf, a, b)))
/* counters */ @@ -324,13 +325,13 @@ void ksft_test_result_code(int exit_code, const char *test_name, break; \ } } while (0)
-static inline int ksft_exit_pass(void) +static inline __noreturn int ksft_exit_pass(void) { ksft_print_cnts(); exit(KSFT_PASS); }
-static inline int ksft_exit_fail(void) +static inline __noreturn int ksft_exit_fail(void) { ksft_print_cnts(); exit(KSFT_FAIL); @@ -357,7 +358,7 @@ static inline int ksft_exit_fail(void) ksft_cnt.ksft_xfail + \ ksft_cnt.ksft_xskip)
-static inline __printf(1, 2) int ksft_exit_fail_msg(const char *msg, ...) +static inline __noreturn __printf(1, 2) int ksft_exit_fail_msg(const char *msg, ...) { int saved_errno = errno; va_list args; @@ -372,7 +373,7 @@ static inline __printf(1, 2) int ksft_exit_fail_msg(const char *msg, ...) exit(KSFT_FAIL); }
-static inline void ksft_exit_fail_perror(const char *msg) +static inline __noreturn void ksft_exit_fail_perror(const char *msg) { #ifndef NOLIBC ksft_exit_fail_msg("%s: %s (%d)\n", msg, strerror(errno), errno); @@ -385,19 +386,19 @@ static inline void ksft_exit_fail_perror(const char *msg) #endif }
-static inline int ksft_exit_xfail(void) +static inline __noreturn int ksft_exit_xfail(void) { ksft_print_cnts(); exit(KSFT_XFAIL); }
-static inline int ksft_exit_xpass(void) +static inline __noreturn int ksft_exit_xpass(void) { ksft_print_cnts(); exit(KSFT_XPASS); }
-static inline __printf(1, 2) int ksft_exit_skip(const char *msg, ...) +static inline __noreturn __printf(1, 2) int ksft_exit_skip(const char *msg, ...) { int saved_errno = errno; va_list args;
On Thu, Apr 11, 2024 at 8:39 AM Nathan Chancellor nathan@kernel.org wrote:
On Wed, Apr 10, 2024 at 04:26:29PM -0700, John Stultz wrote:
Building with clang, I see the following warning:
In file included from posix_timers.c:17: ./../kselftest.h:398:6: warning: variable 'major' is used uninitialized whenever '||' condition is true [-Wsometimes-uninitialized] if (uname(&info) || sscanf(info.release, "%u.%u.", &major, &minor) != 2) ^~~~~~~~~~~~ ./../kselftest.h:401:9: note: uninitialized use occurs here return major > min_major || (major == min_major && minor >= min_minor); ^~~~~
This is a bit of a red-herring as if the uname() call did fail, we would hit ksft_exit_fail_msg() which should exit.
Correct, although we have not really conveyed that to the compiler, right? exit() is noreturn, which means all functions that call exit() unconditionally are also noreturn, such as ksft_exit_fail_msg(). LLVM will figure this out once it performs inlining and such but that happens after clang's static analysis phase that this warning occurs in. I think a better solution would be to add __noreturn to the functions in tools/testing/selftests/kselftest.h that call exit(), so that the compiler is aware of this through all pipeline phases, maybe something like this? It resolves the wawrning for me.
No objection from me if this is the better approach.
Would you send that patch out?
thanks -john
On Thu, Apr 11, 2024 at 11:11:59AM -0700, John Stultz wrote:
On Thu, Apr 11, 2024 at 8:39 AM Nathan Chancellor nathan@kernel.org wrote:
On Wed, Apr 10, 2024 at 04:26:29PM -0700, John Stultz wrote:
Building with clang, I see the following warning:
In file included from posix_timers.c:17: ./../kselftest.h:398:6: warning: variable 'major' is used uninitialized whenever '||' condition is true [-Wsometimes-uninitialized] if (uname(&info) || sscanf(info.release, "%u.%u.", &major, &minor) != 2) ^~~~~~~~~~~~ ./../kselftest.h:401:9: note: uninitialized use occurs here return major > min_major || (major == min_major && minor >= min_minor); ^~~~~
This is a bit of a red-herring as if the uname() call did fail, we would hit ksft_exit_fail_msg() which should exit.
Correct, although we have not really conveyed that to the compiler, right? exit() is noreturn, which means all functions that call exit() unconditionally are also noreturn, such as ksft_exit_fail_msg(). LLVM will figure this out once it performs inlining and such but that happens after clang's static analysis phase that this warning occurs in. I think a better solution would be to add __noreturn to the functions in tools/testing/selftests/kselftest.h that call exit(), so that the compiler is aware of this through all pipeline phases, maybe something like this? It resolves the wawrning for me.
No objection from me if this is the better approach.
Would you send that patch out?
Done: https://lore.kernel.org/20240411-mark-kselftest-exit-funcs-noreturn-v1-1-b02...
If you have to respin this series for some reason, feel free to include that change so that they go together, up to you though.
Cheers, nathan
Building with clang, I'm seeing: posix_timers.c:69:6: warning: absolute value function 'abs' given an argument of type 'long long' but has parameter of type 'int' which may cause truncation of value [-Wabsolute-value] if (abs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2) { ^
So switch to using llabs() instead.
Cc: Shuah Khan shuah@kernel.org Cc: Anna-Maria Behnsen anna-maria@linutronix.de Cc: Frederic Weisbecker frederic@kernel.org Cc: Thomas Gleixner tglx@linutronix.de Cc: Stephen Boyd sboyd@kernel.org Cc: Nathan Chancellor nathan@kernel.org Cc: Nick Desaulniers ndesaulniers@google.com Cc: Bill Wendling morbo@google.com Cc: Justin Stitt justinstitt@google.com Cc: Oleg Nesterov oleg@redhat.com Cc: Andrew Morton akpm@linux-foundation.org Cc: Edward Liaw edliaw@google.com Cc: Carlos Llamas cmllamas@google.com Cc: kernel-team@android.com Cc: linux-kselftest@vger.kernel.org Fixes: 0bc4b0cf1570 ("selftests: add basic posix timers selftests") Signed-off-by: John Stultz jstultz@google.com --- tools/testing/selftests/timers/posix_timers.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c index 348f47176e0a..c001dd79179d 100644 --- a/tools/testing/selftests/timers/posix_timers.c +++ b/tools/testing/selftests/timers/posix_timers.c @@ -66,7 +66,7 @@ static int check_diff(struct timeval start, struct timeval end) diff = end.tv_usec - start.tv_usec; diff += (end.tv_sec - start.tv_sec) * USECS_PER_SEC;
- if (abs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2) { + if (llabs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2) { printf("Diff too high: %lld..", diff); return -1; }
On Wed, Apr 10, 2024 at 4:26 PM John Stultz jstultz@google.com wrote:
After commit 6d029c25b71f ("selftests/timers/posix_timers: Reimplement check_timer_distribution()") I started seeing the following warning building with an older gcc:
posix_timers.c:250:2: warning: format not a string literal and no format arguments [-Wformat-security] 250 | ksft_print_msg(errmsg); | ^~~~~~~~~~~~~~
Fix this up by changing it to ksft_print_msg("%s", errmsg)
Cc: Shuah Khan shuah@kernel.org Cc: Anna-Maria Behnsen anna-maria@linutronix.de Cc: Frederic Weisbecker frederic@kernel.org Cc: Thomas Gleixner tglx@linutronix.de Cc: Stephen Boyd sboyd@kernel.org Cc: Nathan Chancellor nathan@kernel.org Cc: Nick Desaulniers ndesaulniers@google.com Cc: Bill Wendling morbo@google.com Cc: Justin Stitt justinstitt@google.com Cc: Oleg Nesterov oleg@redhat.com Cc: Andrew Morton akpm@linux-foundation.org Cc: Edward Liaw edliaw@google.com Cc: Carlos Llamas cmllamas@google.com Cc: kernel-team@android.com Cc: linux-kselftest@vger.kernel.org Fixes: 6d029c25b71f ("selftests/timers/posix_timers: Reimplement check_timer_distribution()") Signed-off-by: John Stultz jstultz@google.com
Yep, makes sense.
Acked-by: Justin Stitt justinstitt@google.com
tools/testing/selftests/timers/posix_timers.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c index d86a0e00711e..348f47176e0a 100644 --- a/tools/testing/selftests/timers/posix_timers.c +++ b/tools/testing/selftests/timers/posix_timers.c @@ -247,7 +247,7 @@ static int check_timer_distribution(void) ksft_test_result_skip("check signal distribution (old kernel)\n"); return 0; err:
ksft_print_msg(errmsg);
ksft_print_msg("%s", errmsg); return -1;}
-- 2.44.0.478.gd926399ef9-goog
On 04/10, John Stultz wrote:
After commit 6d029c25b71f ("selftests/timers/posix_timers: Reimplement check_timer_distribution()") I started seeing the following warning building with an older gcc:
posix_timers.c:250:2: warning: format not a string literal and no format arguments [-Wformat-security] 250 | ksft_print_msg(errmsg); | ^~~~~~~~~~~~~~
...
- ksft_print_msg(errmsg);
- ksft_print_msg("%s", errmsg); return -1;
Thanks,
Oleg.
On 4/10/24 17:26, John Stultz wrote:
After commit 6d029c25b71f ("selftests/timers/posix_timers:
Tried to apply this for linux-kselftest next with Nathan's patch. I can't find this commit in Linux 6.9-rc3? Is this is timers tree?
Reimplement check_timer_distribution()") I started seeing the following warning building with an older gcc:
posix_timers.c:250:2: warning: format not a string literal and no format arguments [-Wformat-security] 250 | ksft_print_msg(errmsg); | ^~~~~~~~~~~~~~
Fix this up by changing it to ksft_print_msg("%s", errmsg)
Cc: Shuah Khan shuah@kernel.org Cc: Anna-Maria Behnsen anna-maria@linutronix.de Cc: Frederic Weisbecker frederic@kernel.org Cc: Thomas Gleixner tglx@linutronix.de Cc: Stephen Boyd sboyd@kernel.org Cc: Nathan Chancellor nathan@kernel.org Cc: Nick Desaulniers ndesaulniers@google.com Cc: Bill Wendling morbo@google.com Cc: Justin Stitt justinstitt@google.com Cc: Oleg Nesterov oleg@redhat.com Cc: Andrew Morton akpm@linux-foundation.org Cc: Edward Liaw edliaw@google.com Cc: Carlos Llamas cmllamas@google.com Cc: kernel-team@android.com Cc: linux-kselftest@vger.kernel.org Fixes: 6d029c25b71f ("selftests/timers/posix_timers: Reimplement check_timer_distribution()") Signed-off-by: John Stultz jstultz@google.com
tools/testing/selftests/timers/posix_timers.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c index d86a0e00711e..348f47176e0a 100644 --- a/tools/testing/selftests/timers/posix_timers.c +++ b/tools/testing/selftests/timers/posix_timers.c @@ -247,7 +247,7 @@ static int check_timer_distribution(void) ksft_test_result_skip("check signal distribution (old kernel)\n"); return 0; err:
- ksft_print_msg(errmsg);
- ksft_print_msg("%s", errmsg); return -1; }
thanks, -- Shuah
On Thu, Apr 11, 2024 at 1:45 PM Shuah Khan skhan@linuxfoundation.org wrote:
On 4/10/24 17:26, John Stultz wrote:
After commit 6d029c25b71f ("selftests/timers/posix_timers:
Tried to apply this for linux-kselftest next with Nathan's patch. I can't find this commit in Linux 6.9-rc3? Is this is timers tree?
Yes, it in tip/timers/urgent.
thanks -john
On 4/11/24 14:53, John Stultz wrote:
On Thu, Apr 11, 2024 at 1:45 PM Shuah Khan skhan@linuxfoundation.org wrote:
On 4/10/24 17:26, John Stultz wrote:
After commit 6d029c25b71f ("selftests/timers/posix_timers:
Tried to apply this for linux-kselftest next with Nathan's patch. I can't find this commit in Linux 6.9-rc3? Is this is timers tree?
Yes, it in tip/timers/urgent.
Thank you. Assuming this is going through tip/timers/urgent
Acked-by: Shuah Khan skhan@linuxfoundation.org
thanks, -- Shuah
linux-kselftest-mirror@lists.linaro.org
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John Stultz -
Justin Stitt -
Nathan Chancellor -
Oleg Nesterov -
Shuah Khan