diff mbox series

stdlib: Fix BZ #26241 testcase on GNU/Hurd

Message ID 20210324003822.341322-1-samuel.thibault@ens-lyon.org
State Committed, archived
Headers
Series stdlib: Fix BZ #26241 testcase on GNU/Hurd |

Commit Message

Samuel Thibault March 24, 2021, 12:38 a.m. UTC 
  GNU/Hurd's readlink system call is partly implemented in userspace, which
also allocates a buffer on the stack for the result, and thus needs one
more path.
---
 stdlib/tst-canon-bz26341.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Adhemerval Zanella March 24, 2021, 1:04 p.m. UTC | #1 
On 23/03/2021 21:38, Samuel Thibault wrote:
> GNU/Hurd's readlink system call is partly implemented in userspace, which
> also allocates a buffer on the stack for the result, and thus needs one
> more path.

LGTM, thanks.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> ---
>   stdlib/tst-canon-bz26341.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/stdlib/tst-canon-bz26341.c b/stdlib/tst-canon-bz26341.c
> index 6d054596b5..0ddd9aed15 100644
> --- a/stdlib/tst-canon-bz26341.c
> +++ b/stdlib/tst-canon-bz26341.c
> @@ -72,10 +72,11 @@ do_realpath (void *arg)
>        If realpath uses more than 2 * PATH_MAX plus some slack it will trigger
>        a stackoverflow.  */
>   
> +  const size_t syscall_usage = 1 * PATH_MAX + 1024;

Could you also add a comment from where this come from on the description
above?

>     const size_t realpath_usage = 2 * PATH_MAX + 1024;
>     const size_t thread_usage = 1 * PATH_MAX + 1024;
>     size_t stack_size = support_small_thread_stack_size ()
> -		      - realpath_usage - thread_usage;
> +		      - syscall_usage - realpath_usage - thread_usage;
>     char stack[stack_size];
>     char *resolved = stack + stack_size - thread_usage + 1024;
>   
>
Samuel Thibault March 24, 2021, 8:59 p.m. UTC | #2 
Adhemerval Zanella, le mer. 24 mars 2021 10:04:51 -0300, a ecrit:
> 
> 
> On 23/03/2021 21:38, Samuel Thibault wrote:
> > GNU/Hurd's readlink system call is partly implemented in userspace, which
> > also allocates a buffer on the stack for the result, and thus needs one
> > more path.
> 
> LGTM, thanks.
> 
> Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
> 
> > ---
> >   stdlib/tst-canon-bz26341.c | 3 ++-
> >   1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/stdlib/tst-canon-bz26341.c b/stdlib/tst-canon-bz26341.c
> > index 6d054596b5..0ddd9aed15 100644
> > --- a/stdlib/tst-canon-bz26341.c
> > +++ b/stdlib/tst-canon-bz26341.c
> > @@ -72,10 +72,11 @@ do_realpath (void *arg)
> >        If realpath uses more than 2 * PATH_MAX plus some slack it will trigger
> >        a stackoverflow.  */
> > +  const size_t syscall_usage = 1 * PATH_MAX + 1024;
> 
> Could you also add a comment from where this come from on the description
> above?

Ok, and commited.

Thanks,
Samuel
diff mbox series

Patch

diff --git a/stdlib/tst-canon-bz26341.c b/stdlib/tst-canon-bz26341.c
index 6d054596b5..0ddd9aed15 100644
--- a/stdlib/tst-canon-bz26341.c
+++ b/stdlib/tst-canon-bz26341.c
@@ -72,10 +72,11 @@  do_realpath (void *arg)
      If realpath uses more than 2 * PATH_MAX plus some slack it will trigger
      a stackoverflow.  */
 
+  const size_t syscall_usage = 1 * PATH_MAX + 1024;
   const size_t realpath_usage = 2 * PATH_MAX + 1024;
   const size_t thread_usage = 1 * PATH_MAX + 1024;
   size_t stack_size = support_small_thread_stack_size ()
-		      - realpath_usage - thread_usage;
+		      - syscall_usage - realpath_usage - thread_usage;
   char stack[stack_size];
   char *resolved = stack + stack_size - thread_usage + 1024;