diff mbox series

debuginfod/debuginfod-client.c: correct string format on 32bit arches with 64bit time_t

Message ID 20211121221411.404194-1-alex@linutronix.de
State New
Headers show
Series debuginfod/debuginfod-client.c: correct string format on 32bit arches with 64bit time_t | expand

Commit Message

Alexander Kanavin Nov. 21, 2021, 10:14 p.m. UTC
From: Alexander Kanavin <alex.kanavin@gmail.com>

Use intmax_t to print time_t

time_t is platform dependent and some of architectures e.g.
x32, riscv32, arc use 64bit time_t even while they are 32bit
architectures, therefore directly using integer printf formats will not
work portably, use intmax_t to typecast time_t into printf family of
functions.

musl 1.2.0 and above uses time64 on all platforms; glibc 2.34 has added support for
time64 (which might be enabled by distro-wide CFLAGS), with possibly
2.35 or 2.36 making it enabled by default.

Use a plain int for scanning cache_config, as that's what the function
returns.

Signed-off-by: Alexander Kanavin <alex.kanavin@gmail.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>
---
 debuginfod/debuginfod-client.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

Comments

Frank Ch. Eigler Nov. 25, 2021, 5:51 p.m. UTC | #1
Hi -

> Use intmax_t to print time_t
> [...]
> -      if (dprintf(fd, "%ld", cache_config_default_s) < 0)
> +      if (dprintf(fd, "%jd", (intmax_t)cache_config_default_s) < 0)
> [...]

I'm not a compatibility specialist, but note that elfutils is sometimes
built on decade-old toolchains, where use of %lld and (long long) would
certainly work.  We have such in the code base already, whereas this would
be the first %j.

- FChE
Alexander Kanavin Nov. 25, 2021, 6:50 p.m. UTC | #2
According to 'man 3 printf' %j appeared in glibc 2.1 and seems to be C99
feature. That's decidedly ancient.

And may I be allowed to suggest, unless elfutils is tested in upstream CI
with decade-old toolchains, you should not be considering its compatibility
with them.

Alex

On Thu, 25 Nov 2021 at 18:51, Frank Ch. Eigler <fche@redhat.com> wrote:

> Hi -
>
> > Use intmax_t to print time_t
> > [...]
> > -      if (dprintf(fd, "%ld", cache_config_default_s) < 0)
> > +      if (dprintf(fd, "%jd", (intmax_t)cache_config_default_s) < 0)
> > [...]
>
> I'm not a compatibility specialist, but note that elfutils is sometimes
> built on decade-old toolchains, where use of %lld and (long long) would
> certainly work.  We have such in the code base already, whereas this would
> be the first %j.
>
> - FChE
>
>
Frank Ch. Eigler Nov. 25, 2021, 7:24 p.m. UTC | #3
Hi -

> According to 'man 3 printf' %j appeared in glibc 2.1 and seems to be C99
> feature. That's decidedly ancient.

OK. 

> And may I be allowed to suggest, unless elfutils is tested in upstream CI
> with decade-old toolchains, you should not be considering its compatibility
> with them.

Deployment of elfutils is not limited to platforms that happen to be
included in upstream CI that you see.  RHEL7 uses glibc 2.17 from
2012; RHEL6 years before that.  We do not wish to unnecessarily break
them.

- FChE
diff mbox series

Patch

diff --git a/debuginfod/debuginfod-client.c b/debuginfod/debuginfod-client.c
index c875ee62..df9737d2 100644
--- a/debuginfod/debuginfod-client.c
+++ b/debuginfod/debuginfod-client.c
@@ -231,15 +231,15 @@  debuginfod_config_cache(char *config_path,
       if (fd < 0)
         return -errno;
 
-      if (dprintf(fd, "%ld", cache_config_default_s) < 0)
+      if (dprintf(fd, "%jd", (intmax_t)cache_config_default_s) < 0)
         return -errno;
     }
 
-  long cache_config;
+  int cache_config;
   FILE *config_file = fopen(config_path, "r");
   if (config_file)
     {
-      if (fscanf(config_file, "%ld", &cache_config) != 1)
+      if (fscanf(config_file, "%d", &cache_config) != 1)
         cache_config = cache_config_default_s;
       fclose(config_file);
     }
@@ -272,7 +272,7 @@  debuginfod_init_cache (char *cache_path, char *interval_path, char *maxage_path)
   if (fd < 0)
     return -errno;
 
-  if (dprintf(fd, "%ld", cache_clean_default_interval_s) < 0)
+  if (dprintf(fd, "%jd", (intmax_t)cache_clean_default_interval_s) < 0)
     return -errno;
 
   /* init max age config file.  */
@@ -280,7 +280,7 @@  debuginfod_init_cache (char *cache_path, char *interval_path, char *maxage_path)
       && (fd = open(maxage_path, O_CREAT | O_RDWR, DEFFILEMODE)) < 0)
     return -errno;
 
-  if (dprintf(fd, "%ld", cache_default_max_unused_age_s) < 0)
+  if (dprintf(fd, "%jd", (intmax_t)cache_default_max_unused_age_s) < 0)
     return -errno;
 
   return 0;