From: Florian Weimer <fweimer@redhat.com>
To: Mark Wielaard <mjw@redhat.com>
Cc: libc-alpha@sourceware.org
Subject: Re: fortification and valgrind/memcheck (Was: [PATCH BZ#20422] Do not allow asan/msan/tsan and fortify@the same time)
Date: Wed, 05 Oct 2016 11:49:00 -0000 [thread overview]
Message-ID: <cb76ae33-01ee-2ced-68da-fccf8893eeec@redhat.com> (raw)
In-Reply-To: <1475583338.21750.26.camel@redhat.com>
On 10/04/2016 02:15 PM, Mark Wielaard wrote:
> My proposal was to extend __chk_fail (or introduce a new __chk_fail_addr
> function) that provides the address that would have been accessed. Then
> valgrind just intercepts __chk_fail and uses that address to provide
> some additional information.
There many different reasons why __chk_fail might be called. For
example, you get a fortify failure if you call snprintf with a buffer
size that is larger than what is inferred by the compiler. This happens
even if the actual written value fits within the shorter space. So you
have a fortify failure without any invalid memory accesses.
Florian
next prev parent reply other threads:[~2016-10-05 11:49 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-05 17:27 [PATCH BZ#20422] Do not allow asan/msan/tsan and fortify at the same time Maxim Ostapenko
2016-09-05 19:48 ` Andrew Pinski
2016-09-06 8:39 ` Florian Weimer
2016-09-06 8:58 ` Yuri Gribov
2016-09-06 9:13 ` Florian Weimer
2016-09-06 9:20 ` Yuri Gribov
2016-09-06 9:51 ` Florian Weimer
2016-09-09 22:35 ` Kostya Serebryany
[not found] ` <CAN=P9phe_OP+tU+nnDDPEeZCR77w2ddrSX+LtSnx2-42p9JgUg@mail.gmail.com>
2016-09-12 9:36 ` Florian Weimer
2016-09-06 9:16 ` Maxim Ostapenko
2016-09-06 9:44 ` Florian Weimer
2016-09-09 22:36 ` Kostya Serebryany
2016-09-12 9:31 ` Florian Weimer
2016-09-12 18:54 ` Kostya Serebryany
2016-09-17 9:00 ` Yuri Gribov
2016-09-29 8:08 ` Florian Weimer
2016-09-29 9:47 ` Yuri Gribov
2016-09-29 10:04 ` Jakub Jelinek
2016-09-29 10:32 ` Yuri Gribov
2016-09-29 10:44 ` Jakub Jelinek
2016-09-29 10:52 ` Andrew Pinski
2016-09-29 21:23 ` Kostya Serebryany
2016-10-01 21:38 ` Andrew Pinski
2016-10-01 21:50 ` Jakub Jelinek
2016-10-02 7:51 ` Florian Weimer
2016-10-02 9:40 ` Jakub Jelinek
2016-10-02 9:43 ` Florian Weimer
2016-10-02 14:02 ` Yuri Gribov
2016-10-04 0:53 ` Kostya Serebryany
2016-10-04 6:46 ` Jakub Jelinek
2016-10-04 12:15 ` fortification and valgrind/memcheck (Was: [PATCH BZ#20422] Do not allow asan/msan/tsan and fortify@the same time) Mark Wielaard
2016-10-05 11:49 ` Florian Weimer [this message]
2016-10-05 12:02 ` Mark Wielaard
2016-10-05 14:27 ` [PATCH BZ#20422] Do not allow asan/msan/tsan and fortify at the same time Florian Weimer
2016-10-05 15:46 ` Maxim Ostapenko
2016-10-05 16:01 ` Maxim Ostapenko
2016-10-05 16:01 ` Kostya Serebryany
2016-10-05 16:06 ` Zack Weinberg
2016-10-05 16:11 ` Kostya Serebryany
2016-10-05 16:46 ` Zack Weinberg
2016-10-05 17:58 ` Yuri Gribov
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