[bpf-next,v1,2/3] veristat: strerror expects positive number (errno)

Commit Message

Eduard Zingerman Feb. 28, 2025, 7:12 p.m. UTC

Before:

  ./veristat -G @foobar iters.bpf.o
  Failed to open presets in 'foobar': Unknown error -2
  ...

After:

  ./veristat -G @foobar iters.bpf.o
  Failed to open presets in 'foobar': No such file or directory
  ...

Signed-off-by: Eduard Zingerman <[e-mail]>
---
 tools/testing/selftests/bpf/veristat.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Andrii Nakryiko Feb. 28, 2025, 10:44 p.m. UTC | #1

On Fri, Feb 28, 2025 at 11:13 AM Eduard Zingerman <[e-mail]> wrote:
>
> Before:
>
>   ./veristat -G @foobar iters.bpf.o
>   Failed to open presets in 'foobar': Unknown error -2
>   ...
>
> After:
>
>   ./veristat -G @foobar iters.bpf.o
>   Failed to open presets in 'foobar': No such file or directory
>   ...
>
> Signed-off-by: Eduard Zingerman <[e-mail]>
> ---
>  tools/testing/selftests/bpf/veristat.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/veristat.c b/tools/testing/selftests/bpf/veristat.c
> index 8bc462299290..7d13b9234d2c 100644
> --- a/tools/testing/selftests/bpf/veristat.c
> +++ b/tools/testing/selftests/bpf/veristat.c
> @@ -660,7 +660,7 @@ static int append_filter_file(const char *path)
>         f = fopen(path, "r");
>         if (!f) {
>                 err = -errno;
> -               fprintf(stderr, "Failed to open filters in '%s': %s\n", path, strerror(err));
> +               fprintf(stderr, "Failed to open filters in '%s': %s\n", path, strerror(errno));

errno is fragile, -err would be more robust, IMO

>                 return err;
>         }
>
> @@ -1422,7 +1422,7 @@ static int append_var_preset_file(const char *filename)
>         f = fopen(filename, "rt");
>         if (!f) {
>                 err = -errno;
> -               fprintf(stderr, "Failed to open presets in '%s': %s\n", filename, strerror(err));
> +               fprintf(stderr, "Failed to open presets in '%s': %s\n", filename, strerror(errno));
>                 return -EINVAL;
>         }
>
> --
> 2.48.1
>

Eduard Zingerman Feb. 28, 2025, 10:46 p.m. UTC | #2

On Fri, 2025-02-28 at 14:44 -0800, Andrii Nakryiko wrote:

[...]

> > diff --git a/tools/testing/selftests/bpf/veristat.c b/tools/testing/selftests/bpf/veristat.c
> > index 8bc462299290..7d13b9234d2c 100644
> > --- a/tools/testing/selftests/bpf/veristat.c
> > +++ b/tools/testing/selftests/bpf/veristat.c
> > @@ -660,7 +660,7 @@ static int append_filter_file(const char *path)
> >         f = fopen(path, "r");
> >         if (!f) {
> >                 err = -errno;
> > -               fprintf(stderr, "Failed to open filters in '%s': %s\n", path, strerror(err));
> > +               fprintf(stderr, "Failed to open filters in '%s': %s\n", path, strerror(errno));
> 
> errno is fragile, -err would be more robust, IMO

Sure, I'll send v2.

[...]

Patch

diff --git a/tools/testing/selftests/bpf/veristat.c b/tools/testing/selftests/bpf/veristat.c
index 8bc462299290..7d13b9234d2c 100644
--- a/tools/testing/selftests/bpf/veristat.c
+++ b/tools/testing/selftests/bpf/veristat.c
@@ -660,7 +660,7 @@  static int append_filter_file(const char *path)
 	f = fopen(path, "r");
 	if (!f) {
 		err = -errno;
-		fprintf(stderr, "Failed to open filters in '%s': %s\n", path, strerror(err));
+		fprintf(stderr, "Failed to open filters in '%s': %s\n", path, strerror(errno));
 		return err;
 	}
 
@@ -1422,7 +1422,7 @@  static int append_var_preset_file(const char *filename)
 	f = fopen(filename, "rt");
 	if (!f) {
 		err = -errno;
-		fprintf(stderr, "Failed to open presets in '%s': %s\n", filename, strerror(err));
+		fprintf(stderr, "Failed to open presets in '%s': %s\n", filename, strerror(errno));
 		return -EINVAL;
 	}