[PATCH 6.6.y] kselftest: Add a ksft_perror() helper

[PATCH 6.6.y] kselftest: Add a ksft_perror() helper

[Edward Liaw]

From: Mark Brown <broonie@kernel.org>

[ Upstream commit 907f33028871fa7c9a3db1efd467b78ef82cce20 ]

The standard library perror() function provides a convenient way to print
an error message based on the current errno but this doesn't play nicely
with KTAP output. Provide a helper which does an equivalent thing in a KTAP
compatible format.

nolibc doesn't have a strerror() and adding the table of strings required
doesn't seem like a good fit for what it's trying to do so when we're using
that only print the errno.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Stable-dep-of: 071af0c9e582 ("selftests: timers: Convert posix_timers test to generate KTAP output")
Signed-off-by: Edward Liaw <edliaw@google.com>
---
 tools/testing/selftests/kselftest.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h
index e8eecbc83a60..ad7b97e16f37 100644
--- a/tools/testing/selftests/kselftest.h
+++ b/tools/testing/selftests/kselftest.h
@@ -48,6 +48,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <stdarg.h>
+#include <string.h>
 #include <stdio.h>
 #include <sys/utsname.h>
 #endif
@@ -156,6 +157,19 @@ static inline void ksft_print_msg(const char *msg, ...)
 	va_end(args);
 }
 
+static inline void ksft_perror(const char *msg)
+{
+#ifndef NOLIBC
+	ksft_print_msg("%s: %s (%d)\n", msg, strerror(errno), errno);
+#else
+	/*
+	 * nolibc doesn't provide strerror() and it seems
+	 * inappropriate to add one, just print the errno.
+	 */
+	ksft_print_msg("%s: %d)\n", msg, errno);
+#endif
+}
+
 static inline void ksft_test_result_pass(const char *msg, ...)
 {
 	int saved_errno = errno;
-- 
2.44.0.769.g3c40516874-goog

Re: [PATCH 6.6.y] kselftest: Add a ksft_perror() helper

[Greg KH]

On Tue, Apr 30, 2024 at 01:06:27AM +0000, Edward Liaw wrote:
> From: Mark Brown <broonie@kernel.org>
> 
> [ Upstream commit 907f33028871fa7c9a3db1efd467b78ef82cce20 ]
> 
> The standard library perror() function provides a convenient way to print
> an error message based on the current errno but this doesn't play nicely
> with KTAP output. Provide a helper which does an equivalent thing in a KTAP
> compatible format.
> 
> nolibc doesn't have a strerror() and adding the table of strings required
> doesn't seem like a good fit for what it's trying to do so when we're using
> that only print the errno.
> 
> Signed-off-by: Mark Brown <broonie@kernel.org>
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
> Stable-dep-of: 071af0c9e582 ("selftests: timers: Convert posix_timers test to generate KTAP output")
> Signed-off-by: Edward Liaw <edliaw@google.com>
> ---
>  tools/testing/selftests/kselftest.h | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)

This commit is already in 6.6.29, why submit it again?

confused,

greg k-h

Re: [PATCH 6.6.y] kselftest: Add a ksft_perror() helper

[Edward Liaw]

On Tue, Apr 30, 2024 at 12:51 AM Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Tue, Apr 30, 2024 at 01:06:27AM +0000, Edward Liaw wrote:
> > From: Mark Brown <broonie@kernel.org>
> >
> > [ Upstream commit 907f33028871fa7c9a3db1efd467b78ef82cce20 ]
> >
> > The standard library perror() function provides a convenient way to print
> > an error message based on the current errno but this doesn't play nicely
> > with KTAP output. Provide a helper which does an equivalent thing in a KTAP
> > compatible format.
> >
> > nolibc doesn't have a strerror() and adding the table of strings required
> > doesn't seem like a good fit for what it's trying to do so when we're using
> > that only print the errno.
> >
> > Signed-off-by: Mark Brown <broonie@kernel.org>
> > Reviewed-by: Kees Cook <keescook@chromium.org>
> > Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
> > Stable-dep-of: 071af0c9e582 ("selftests: timers: Convert posix_timers test to generate KTAP output")
> > Signed-off-by: Edward Liaw <edliaw@google.com>
> > ---
> >  tools/testing/selftests/kselftest.h | 14 ++++++++++++++
> >  1 file changed, 14 insertions(+)
>
> This commit is already in 6.6.29, why submit it again?

Hi Greg,
I double checked and I don't see this commit in 6.6.29.   As far as I
can tell the earliest it has been merged is in 6.7.1.  Do you mind
rechecking?

Thank you,
Edward

>
> confused,
>
> greg k-h

Re: [PATCH 6.6.y] kselftest: Add a ksft_perror() helper

[Lee Jones]

On Tue, 30 Apr 2024, Greg KH wrote:

> On Tue, Apr 30, 2024 at 01:06:27AM +0000, Edward Liaw wrote:
> > From: Mark Brown <broonie@kernel.org>
> > 
> > [ Upstream commit 907f33028871fa7c9a3db1efd467b78ef82cce20 ]
> > 
> > The standard library perror() function provides a convenient way to print
> > an error message based on the current errno but this doesn't play nicely
> > with KTAP output. Provide a helper which does an equivalent thing in a KTAP
> > compatible format.
> > 
> > nolibc doesn't have a strerror() and adding the table of strings required
> > doesn't seem like a good fit for what it's trying to do so when we're using
> > that only print the errno.
> > 
> > Signed-off-by: Mark Brown <broonie@kernel.org>
> > Reviewed-by: Kees Cook <keescook@chromium.org>
> > Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
> > Stable-dep-of: 071af0c9e582 ("selftests: timers: Convert posix_timers test to generate KTAP output")
> > Signed-off-by: Edward Liaw <edliaw@google.com>
> > ---
> >  tools/testing/selftests/kselftest.h | 14 ++++++++++++++
> >  1 file changed, 14 insertions(+)
> 
> This commit is already in 6.6.29, why submit it again?

I don't see this in v6.6.29.

The function that it adds is called, but doesn't exist however:

stable/linux-6.6.y:tools/testing/selftests/timers/posix_timers.c:               ksft_perror("Can't call gettimeofday()");
stable/linux-6.6.y:tools/testing/selftests/timers/posix_timers.c:               ksft_perror("Can't set timer");
stable/linux-6.6.y:tools/testing/selftests/timers/posix_timers.c:               ksft_perror("Can't call gettimeofday()");
stable/linux-6.6.y:tools/testing/selftests/timers/posix_timers.c:               ksft_perror("Can't create timer");
stable/linux-6.6.y:tools/testing/selftests/timers/posix_timers.c:               ksft_perror("Can't call gettimeofday()");
stable/linux-6.6.y:tools/testing/selftests/timers/posix_timers.c:               ksft_perror("Can't set timer");
stable/linux-6.6.y:tools/testing/selftests/timers/posix_timers.c:               ksft_perror("Can't call gettimeofday()");

We should probably have this added to linux-6.6.y.

-- 
Lee Jones [李琼斯]

Re: [PATCH 6.6.y] kselftest: Add a ksft_perror() helper

[Greg KH]

On Tue, Apr 30, 2024 at 10:29:43AM -0700, Edward Liaw wrote:
> On Tue, Apr 30, 2024 at 12:51 AM Greg KH <gregkh@linuxfoundation.org> wrote:
> >
> > On Tue, Apr 30, 2024 at 01:06:27AM +0000, Edward Liaw wrote:
> > > From: Mark Brown <broonie@kernel.org>
> > >
> > > [ Upstream commit 907f33028871fa7c9a3db1efd467b78ef82cce20 ]
> > >
> > > The standard library perror() function provides a convenient way to print
> > > an error message based on the current errno but this doesn't play nicely
> > > with KTAP output. Provide a helper which does an equivalent thing in a KTAP
> > > compatible format.
> > >
> > > nolibc doesn't have a strerror() and adding the table of strings required
> > > doesn't seem like a good fit for what it's trying to do so when we're using
> > > that only print the errno.
> > >
> > > Signed-off-by: Mark Brown <broonie@kernel.org>
> > > Reviewed-by: Kees Cook <keescook@chromium.org>
> > > Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
> > > Stable-dep-of: 071af0c9e582 ("selftests: timers: Convert posix_timers test to generate KTAP output")
> > > Signed-off-by: Edward Liaw <edliaw@google.com>
> > > ---
> > >  tools/testing/selftests/kselftest.h | 14 ++++++++++++++
> > >  1 file changed, 14 insertions(+)
> >
> > This commit is already in 6.6.29, why submit it again?
> 
> Hi Greg,
> I double checked and I don't see this commit in 6.6.29.   As far as I
> can tell the earliest it has been merged is in 6.7.1.  Do you mind
> rechecking?

My fault, yes, you are right, it is not in 6.6.y, I don't know what I
was looking at.

Can you resubmit it if it really is needed there?

thanks,

greg k-h