This is the mail archive of the
mailing list for the glibc project.
Re: [BZ#17090/17620/17621]: fix DTV race, assert, and DTV_SURPLUS Static TLS limit
- From: Richard Henderson <rth at twiddle dot net>
- To: Alexandre Oliva <aoliva at redhat dot com>, Alan Modra <amodra at gmail dot com>
- Cc: Roland McGrath <roland at hack dot frob dot com>, codonell at redhat dot com, libc-alpha at sourceware dot org, rth at redhat dot com
- Date: Mon, 16 Mar 2015 12:01:05 -0700
- Subject: Re: [BZ#17090/17620/17621]: fix DTV race, assert, and DTV_SURPLUS Static TLS limit
- Authentication-results: sourceware.org; auth=none
- References: <ord28kkvpq dot fsf at free dot home> <20141118224048 dot 600312C3B23 at topped-with-meat dot com> <orppcjotfm dot fsf at free dot home> <20141120021703 dot 86F032C3B18 at topped-with-meat dot com> <or8uj6qse8 dot fsf at free dot home> <oroas0mzri dot fsf at free dot home> <orlhmgyall dot fsf at free dot home> <orlhlgdb8d dot fsf at livre dot home> <ormw411b25 dot fsf at livre dot home> <20150304050529 dot GD26435 at bubble dot grove dot modra dot org> <20150304110430 dot GE26435 at bubble dot grove dot modra dot org> <ory4nb6mmc dot fsf at livre dot home> <orlhja7vgs dot fsf at livre dot home>
On 03/05/2015 05:42 PM, Alexandre Oliva wrote:
> On Mar 5, 2015, Alexandre Oliva <email@example.com> wrote:
>> > On Mar 4, 2015, Alan Modra <firstname.lastname@example.org> wrote:
>>> >> On Wed, Mar 04, 2015 at 03:35:29PM +1030, Alan Modra wrote:
>>>> >>> As does nptl/tst-stack4 on x86_64 if tst-stack4mod.so is built with
>>>> >>> -mtls-dialect=gnu2.
>>> >> This on top of your patch gets me past the segfault in free().
>>> >> I now hit another segfault, tst-stack4mod.c:function somehow has
>>> >> var == NULL.
>> > Thanks, here's an incremental patch that fixes the attempt to release
>> > the pointer from an entry past the end of the dtv (that you fixed
>> > above); that ensures we don't use, in a TLS Descriptor, the generation
>> > count of an earlier map that used the same dtv slot (this ensures we
>> > update the DTV instead of happily using a NULL pointer in there); and
>> > that silences a -Wundef warning in nptl_db, that I had missed when I
>> > updated the #ifs for the last-posted version of the patch.
>> > I'm now running a full build and test cycle with the combined patch,
>> > that I will post once it (hopefully ;-) completes successfully.
> Success (x86_64-linux-gnu, with -mtls-dialect=gnu2)!
The patch looks good to me. (And success with aarch64-linux-gnu!)