false positive with dtls

[ramosian-glider]

Originally reported on Google Code with ID 44

lib/msan/lit_tests/dtls_test.c currently produces a false report
because we don't know the dynamic tls and don't clean its shadow on thread exit.

The behavior is different with glibs < 2.19 and >= 2.19,
see https://groups.google.com/forum/#!topic/address-sanitizer/BfwYD8HMxTM
With < 2.19 dtls will be created by malloc and thus will be poisoned,
with >= 2.19 dtls will be created by mmap and this will not be poisoned,
but we still must unpoison it on thread exit.

We'l need to use the new __tls_get_addr interceptor machinery 
to clean shadow for dtls on its creation and on thread exit.

Most of the code is already there (lib/sanitizer_common/sanitizer_tls_get_addr.h)

Reported by konstantin.s.serebryany on 2014-01-29 09:42:03

[ramosian-glider]

Reported by konstantin.s.serebryany on 2014-01-29 09:42:14

[ramosian-glider]

Reported by konstantin.s.serebryany on 2014-01-29 10:33:56

[ramosian-glider]

Btw, where does ASan clear shadow for DTLS?
I don't see anything like that.
And I think it does not need it either.

Reported by eugenis@google.com on 2014-06-25 11:02:35

[ramosian-glider]

'cause thread-locals don't have redzones

Reported by eugenis@google.com on 2014-06-25 11:03:02

[ramosian-glider]

Fixed:
http://llvm.org/viewvc/llvm-project?view=revision&revision=211683

Reported by eugenis@google.com on 2014-06-25 11:39:19

• Status changed: Fixed

[ramosian-glider]

Adding Project:MemorySanitizer as part of GitHub migration.

Reported by glider@google.com on 2015-07-30 09:22:26

• Labels added: ProjectMemorySanitizer