Re: [PATCH]: Add to the stack size the TLS size before allocating

["Carlos O'Donell" <carlos at systemhalted dot org>]

On Fri, Mar 23, 2012 at 1:44 PM, asharif tools <asharif.tools@gmail.com> wrote:
> Currently glibc subtracts from the stack size the TLS size and the
> stack allocation can fail when the TLS is large enough. See this bug:
> http://sourceware.org/bugzilla/show_bug.cgi?id=11787. This patch
> addresses that:
>
>
> http://sourceware.org/bugzilla/show_bug.cgi?id=11787
>
> When stackallocate() is called, glibc allocates a stack space of:
> requested_size - TLS_size. The TLS_size could be anything, and in the case of
> Chrome built with -fprofile-generate, is large enough so stack allocation fails.
> This patch increases the stack size by the TLS_size so that stack allocation
> doesn't fail when the TLS is larger than the request size.
>
> --- ./glibc-2.11.1/nptl/allocatestack.c 2012-03-21 22:36:08.810112972 -0700
> +++ ./glibc-2.11.1/nptl/allocatestack.c 2012-03-21 22:39:59.469273930 -0700
> @@ -349,6 +349,10 @@
> ? /* Get the stack size from the attribute if it is set. ?Otherwise we
> ? ? ?use the default we determined at start time. ?*/
> ? size = attr->stacksize ?: __default_stacksize;
> + ?size += __static_tls_size;
> +#if TLS_TCB_AT_TP
> + ?size += TLS_TCB_SIZE;
> +#endif
>
> ? /* Get memory for the stack. ?*/
> ? if (__builtin_expect (attr->flags & ATTR_FLAG_STACKADDR, 0))
> @@ -358,7 +363,7 @@
> ? ? ? /* If the user also specified the size of the stack make sure it
> ? ? ? ? is large enough. ?*/
> ? ? ? if (attr->stacksize != 0
> - ? ? ? ? && attr->stacksize < (__static_tls_size + MINIMAL_REST_STACK))
> + ? ? ? ? && attr->stacksize < (MINIMAL_REST_STACK))
> ? ? ? ?return EINVAL;
>
> ? ? ? /* Adjust stack size for alignment of the TLS block. ?*/
>
>
> Any feedback on this patch would be appreciated.

I responded in the bug. Thanks for posting.

Cheers,
Carlos.