* [PATCH v3] argp-help: Get rid of alloca.
@ 2023-09-13 16:00 Joe Simmons-Talbott
2023-09-13 19:45 ` Adhemerval Zanella Netto
0 siblings, 1 reply; 3+ messages in thread
From: Joe Simmons-Talbott @ 2023-09-13 16:00 UTC (permalink / raw)
To: libc-alpha; +Cc: Joe Simmons-Talbott
Replace alloca with malloc and a scratch_buffer to avoid potential stack
overflow.
Checked on x86_64-linux-gnu
---
argp/argp-help.c | 40 ++++++++++++++++++++++------------------
1 file changed, 22 insertions(+), 18 deletions(-)
diff --git a/argp/argp-help.c b/argp/argp-help.c
index d019ed58d2..54a15a8233 100644
--- a/argp/argp-help.c
+++ b/argp/argp-help.c
@@ -25,21 +25,7 @@
#include <config.h>
#endif
-/* AIX requires this to be the first thing in the file. */
-#ifndef __GNUC__
-# if HAVE_ALLOCA_H || defined _LIBC
-# include <alloca.h>
-# else
-# ifdef _AIX
-#pragma alloca
-# else
-# ifndef alloca /* predefined by HP cc +Olibcalls */
-char *alloca ();
-# endif
-# endif
-# endif
-#endif
-
+#include <scratch_buffer.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdlib.h>
@@ -1450,8 +1436,14 @@ hol_usage (struct hol *hol, argp_fmtstream_t stream)
{
unsigned nentries;
struct hol_entry *entry;
- char *short_no_arg_opts = alloca (strlen (hol->short_options) + 1);
- char *snao_end = short_no_arg_opts;
+ char *short_no_arg_opts;
+ char *snao_end;
+
+ short_no_arg_opts = malloc (strlen (hol->short_options) + 1);
+ assert (short_no_arg_opts != NULL);
+
+ snao_end = short_no_arg_opts;
+
/* First we put a list of short options without arguments. */
for (entry = hol->entries, nentries = hol->num_entries
@@ -1478,6 +1470,8 @@ hol_usage (struct hol *hol, argp_fmtstream_t stream)
; entry++, nentries--)
hol_entry_long_iterate (entry, usage_long_opt,
entry->argp->argp_domain, stream);
+
+ free (short_no_arg_opts);
}
}
\f
@@ -1698,7 +1692,15 @@ _help (const struct argp *argp, const struct argp_state *state, FILE *stream,
{
int first_pattern = 1, more_patterns;
size_t num_pattern_levels = argp_args_levels (argp);
- char *pattern_levels = alloca (num_pattern_levels);
+ struct scratch_buffer buf;
+ scratch_buffer_init (&buf);
+ char *pattern_levels;
+ bool result;
+
+ result = scratch_buffer_set_array_size (&buf, 1, num_pattern_levels);
+ assert (result);
+
+ pattern_levels = buf.data;
memset (pattern_levels, 0, num_pattern_levels);
@@ -1746,6 +1748,8 @@ _help (const struct argp *argp, const struct argp_state *state, FILE *stream,
first_pattern = 0;
}
while (more_patterns);
+
+ scratch_buffer_free (&buf);
}
if (flags & ARGP_HELP_PRE_DOC)
--
2.39.2
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v3] argp-help: Get rid of alloca.
2023-09-13 16:00 [PATCH v3] argp-help: Get rid of alloca Joe Simmons-Talbott
@ 2023-09-13 19:45 ` Adhemerval Zanella Netto
2023-09-13 20:45 ` Joe Simmons-Talbott
0 siblings, 1 reply; 3+ messages in thread
From: Adhemerval Zanella Netto @ 2023-09-13 19:45 UTC (permalink / raw)
To: Joe Simmons-Talbott, libc-alpha
On 13/09/23 13:00, Joe Simmons-Talbott wrote:
> Replace alloca with malloc and a scratch_buffer to avoid potential stack
> overflow.
>
> Checked on x86_64-linux-gnu
> ---
> argp/argp-help.c | 40 ++++++++++++++++++++++------------------
> 1 file changed, 22 insertions(+), 18 deletions(-)
>
> diff --git a/argp/argp-help.c b/argp/argp-help.c
> index d019ed58d2..54a15a8233 100644
> --- a/argp/argp-help.c
> +++ b/argp/argp-help.c
> @@ -25,21 +25,7 @@
> #include <config.h>
> #endif
>
> -/* AIX requires this to be the first thing in the file. */
> -#ifndef __GNUC__
> -# if HAVE_ALLOCA_H || defined _LIBC
> -# include <alloca.h>
> -# else
> -# ifdef _AIX
> -#pragma alloca
> -# else
> -# ifndef alloca /* predefined by HP cc +Olibcalls */
> -char *alloca ();
> -# endif
> -# endif
> -# endif
> -#endif
> -
> +#include <scratch_buffer.h>
> #include <stdbool.h>
> #include <stddef.h>
> #include <stdlib.h>
> @@ -1450,8 +1436,14 @@ hol_usage (struct hol *hol, argp_fmtstream_t stream)
> {
> unsigned nentries;
> struct hol_entry *entry;
> - char *short_no_arg_opts = alloca (strlen (hol->short_options) + 1);
> - char *snao_end = short_no_arg_opts;
> + char *short_no_arg_opts;
> + char *snao_end;
> +
> + short_no_arg_opts = malloc (strlen (hol->short_options) + 1);
> + assert (short_no_arg_opts != NULL);
> +
> + snao_end = short_no_arg_opts;
> +
>
> /* First we put a list of short options without arguments. */
> for (entry = hol->entries, nentries = hol->num_entries
> @@ -1478,6 +1470,8 @@ hol_usage (struct hol *hol, argp_fmtstream_t stream)
> ; entry++, nentries--)
> hol_entry_long_iterate (entry, usage_long_opt,
> entry->argp->argp_domain, stream);
> +
> + free (short_no_arg_opts);
> }
> }
> \f
> @@ -1698,7 +1692,15 @@ _help (const struct argp *argp, const struct argp_state *state, FILE *stream,
> {
> int first_pattern = 1, more_patterns;
> size_t num_pattern_levels = argp_args_levels (argp);
> - char *pattern_levels = alloca (num_pattern_levels);
> + struct scratch_buffer buf;
> + scratch_buffer_init (&buf);
> + char *pattern_levels;
> + bool result;
> +
> + result = scratch_buffer_set_array_size (&buf, 1, num_pattern_levels);
> + assert (result);
> +
> + pattern_levels = buf.data;
>
> memset (pattern_levels, 0, num_pattern_levels);
>
Use malloc here as well.
> @@ -1746,6 +1748,8 @@ _help (const struct argp *argp, const struct argp_state *state, FILE *stream,
> first_pattern = 0;
> }
> while (more_patterns);
> +
> + scratch_buffer_free (&buf);
> }
>
> if (flags & ARGP_HELP_PRE_DOC)
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v3] argp-help: Get rid of alloca.
2023-09-13 19:45 ` Adhemerval Zanella Netto
@ 2023-09-13 20:45 ` Joe Simmons-Talbott
0 siblings, 0 replies; 3+ messages in thread
From: Joe Simmons-Talbott @ 2023-09-13 20:45 UTC (permalink / raw)
To: Adhemerval Zanella Netto; +Cc: libc-alpha
On Wed, Sep 13, 2023 at 04:45:21PM -0300, Adhemerval Zanella Netto wrote:
>
>
> On 13/09/23 13:00, Joe Simmons-Talbott wrote:
> > Replace alloca with malloc and a scratch_buffer to avoid potential stack
> > overflow.
> >
> > Checked on x86_64-linux-gnu
> > ---
> > argp/argp-help.c | 40 ++++++++++++++++++++++------------------
> > 1 file changed, 22 insertions(+), 18 deletions(-)
> >
> > diff --git a/argp/argp-help.c b/argp/argp-help.c
> > index d019ed58d2..54a15a8233 100644
> > --- a/argp/argp-help.c
> > +++ b/argp/argp-help.c
> > @@ -25,21 +25,7 @@
> > #include <config.h>
> > #endif
> >
> > -/* AIX requires this to be the first thing in the file. */
> > -#ifndef __GNUC__
> > -# if HAVE_ALLOCA_H || defined _LIBC
> > -# include <alloca.h>
> > -# else
> > -# ifdef _AIX
> > -#pragma alloca
> > -# else
> > -# ifndef alloca /* predefined by HP cc +Olibcalls */
> > -char *alloca ();
> > -# endif
> > -# endif
> > -# endif
> > -#endif
> > -
> > +#include <scratch_buffer.h>
> > #include <stdbool.h>
> > #include <stddef.h>
> > #include <stdlib.h>
> > @@ -1450,8 +1436,14 @@ hol_usage (struct hol *hol, argp_fmtstream_t stream)
> > {
> > unsigned nentries;
> > struct hol_entry *entry;
> > - char *short_no_arg_opts = alloca (strlen (hol->short_options) + 1);
> > - char *snao_end = short_no_arg_opts;
> > + char *short_no_arg_opts;
> > + char *snao_end;
> > +
> > + short_no_arg_opts = malloc (strlen (hol->short_options) + 1);
> > + assert (short_no_arg_opts != NULL);
> > +
> > + snao_end = short_no_arg_opts;
> > +
> >
> > /* First we put a list of short options without arguments. */
> > for (entry = hol->entries, nentries = hol->num_entries
> > @@ -1478,6 +1470,8 @@ hol_usage (struct hol *hol, argp_fmtstream_t stream)
> > ; entry++, nentries--)
> > hol_entry_long_iterate (entry, usage_long_opt,
> > entry->argp->argp_domain, stream);
> > +
> > + free (short_no_arg_opts);
> > }
> > }
> > \f
> > @@ -1698,7 +1692,15 @@ _help (const struct argp *argp, const struct argp_state *state, FILE *stream,
> > {
> > int first_pattern = 1, more_patterns;
> > size_t num_pattern_levels = argp_args_levels (argp);
> > - char *pattern_levels = alloca (num_pattern_levels);
> > + struct scratch_buffer buf;
> > + scratch_buffer_init (&buf);
> > + char *pattern_levels;
> > + bool result;
> > +
> > + result = scratch_buffer_set_array_size (&buf, 1, num_pattern_levels);
> > + assert (result);
> > +
> > + pattern_levels = buf.data;
> >
> > memset (pattern_levels, 0, num_pattern_levels);
> >
>
>
> Use malloc here as well.
Done in v4.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2023-09-13 16:00 [PATCH v3] argp-help: Get rid of alloca Joe Simmons-Talbott
2023-09-13 19:45 ` Adhemerval Zanella Netto
2023-09-13 20:45 ` Joe Simmons-Talbott
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