Re: [PATCH] gencat: Get rid of alloca.

[Joe Simmons-Talbott <josimmon@redhat.com>]

On Thu, Aug 03, 2023 at 09:10:26AM -0400, Joe Simmons-Talbott via Libc-alpha wrote:
> On Thu, Jul 13, 2023 at 12:04:10PM -0400, Joe Simmons-Talbott wrote:
> > Convert to scratch_buffers to avoid potential stack overflow.
> 
> Ping.
Ping.

Thanks,
Joe
> 
> Thanks,
> Joe
> > 
> > Checked on x86_64-linux-gnu and aarch64-linux-gnu.
> > ---
> >  catgets/gencat.c | 37 +++++++++++++++++++++++++++++++------
> >  1 file changed, 31 insertions(+), 6 deletions(-)
> > 
> > diff --git a/catgets/gencat.c b/catgets/gencat.c
> > index 9cacc801b5..63bdbf86a6 100644
> > --- a/catgets/gencat.c
> > +++ b/catgets/gencat.c
> > @@ -32,6 +32,7 @@
> >  #include <limits.h>
> >  #include <nl_types.h>
> >  #include <obstack.h>
> > +#include <scratch_buffer.h>
> >  #include <stdint.h>
> >  #include <stdio.h>
> >  #include <stdlib.h>
> > @@ -854,6 +855,10 @@ write_out (struct catalog *catalog, const char *output_name,
> >    uint32_t *array1, *array2;
> >    size_t cnt;
> >    int fd;
> > +  struct scratch_buffer buf1;
> > +  scratch_buffer_init (&buf1);
> > +  struct scratch_buffer buf2;
> > +  scratch_buffer_init (&buf2);
> >  
> >    /* If not otherwise told try to read file with existing
> >       translations.  */
> > @@ -929,9 +934,19 @@ write_out (struct catalog *catalog, const char *output_name,
> >  
> >    uint32_t array_size = best_size * best_depth * sizeof (uint32_t) * 3;
> >    /* Allocate room for all needed arrays.  */
> > -  array1 = (uint32_t *) alloca (array_size);
> > +  if (!scratch_buffer_set_array_size (&buf1, best_size * best_depth * 3,
> > +			              sizeof (uint32_t)))
> > +    error (EXIT_FAILURE, ENOMEM, gettext ("cannot allocate memory"));
> > +  array1 = buf1.data;
> >    memset (array1, '\0', array_size);
> > -  array2 = (uint32_t *) alloca (array_size);
> > +
> > +  if (!scratch_buffer_set_array_size (&buf2, best_size * best_depth * 3,
> > +			              sizeof (uint32_t)))
> > +    {
> > +      scratch_buffer_free (&buf1);
> > +      error (EXIT_FAILURE, ENOMEM, gettext ("cannot allocate memory"));
> > +    }
> > +  array2 = buf2.data;
> >    obstack_init (&string_pool);
> >  
> >    set_run = catalog->all_sets;
> > @@ -979,8 +994,12 @@ write_out (struct catalog *catalog, const char *output_name,
> >      {
> >        fd = creat (output_name, 0666);
> >        if (fd < 0)
> > -	error (EXIT_FAILURE, errno, gettext ("cannot open output file `%s'"),
> > -	       output_name);
> > +	{
> > +	  scratch_buffer_free (&buf1);
> > +	  scratch_buffer_free (&buf2);
> > +	  error (EXIT_FAILURE, errno, gettext ("cannot open output file `%s'"),
> > +	         output_name);
> > +	}
> >      }
> >  
> >    /* Write out header.  */
> > @@ -1019,8 +1038,12 @@ write_out (struct catalog *catalog, const char *output_name,
> >  	{
> >  	  fp = fopen (header_name, "w");
> >  	  if (fp == NULL)
> > -	    error (EXIT_FAILURE, errno,
> > -		   gettext ("cannot open output file `%s'"), header_name);
> > +	    {
> > +	      scratch_buffer_free (&buf1);
> > +	      scratch_buffer_free (&buf2);
> > +	      error (EXIT_FAILURE, errno,
> > +		     gettext ("cannot open output file `%s'"), header_name);
> > +	    }
> >  	}
> >  
> >        /* Iterate over all sets and all messages.  */
> > @@ -1066,6 +1089,8 @@ write_out (struct catalog *catalog, const char *output_name,
> >        if (fp != stdout)
> >  	fclose (fp);
> >      }
> > +  scratch_buffer_free (&buf1);
> > +  scratch_buffer_free (&buf2);
> >  }
> >  
> >  
> > -- 
> > 2.39.2
> > 
>