Jakub Jelinek <ja...@redhat.com> writes:
> On Mon, Jun 04, 2012 at 11:19:46PM -0700, Ian Lance Taylor wrote:
>> This patch to libgo includes the TLS size in the requested stack size of
>> a new thread, if possible. This relies on the glibc-specific (and
>> undocumented) _dl_get_tls_static_info call. This is particularly
>> necessary when using glibc, because glibc removes the static TLS size
>> from the requested stack space, and gives an error if there is not
>> enough space. That means that a program that has a lot of TLS variables
>> will fail bizarrely, or worse may simply get a stack overflow
>> segmentation violation at runtime. This patch is far from perfect, but
>> at least works around that problem for such programs. Bootstrapped and
>> ran Go testsuite on x86_64-unknown-linux-gnu. Committed to mainline and
>> 4.7 branch.
>
> That is a very bad idea. _dl_get_tls_static_info is @@GLIBC_PRIVATE symbol,
> therefore it must not be used by anything but glibc itself, may change or
> may be removed at any time. Not using of GLIBC_PRIVATE symbols are even
> enforced
> by rpm, so if you build gcc as rpm, it won't install. So especially
> committing that to 4.7 branch is fatal.
>
> Talk to libc-al...@sourceware.org for what should be done instead.
I knew it was nonportable, but I didn't realize that it would break rpm.
Disabled per richi's request, like so. Patch committed to mainline and
4.7 branch.
Ian
diff -r 76c6ab4f8cdd libgo/runtime/proc.c
--- a/libgo/runtime/proc.c Mon Jun 04 23:18:14 2012 -0700
+++ b/libgo/runtime/proc.c Tue Jun 05 06:09:41 2012 -0700
@@ -1122,6 +1122,7 @@
stacksize = PTHREAD_STACK_MIN;
+#if 0
#ifdef HAVE__DL_GET_TLS_STATIC_INFO
{
/* On GNU/Linux the static TLS size is taken out of
@@ -1142,6 +1143,7 @@
stacksize += tlssize;
}
#endif
+#endif
if(pthread_attr_setstacksize(&attr, stacksize) != 0)
runtime_throw("pthread_attr_setstacksize");
