Currently correct programs can deadlock after fork, because atomic operations and async-signal-safe calls are not async-signal-safe under tsan.
With this change:
- if a single-threaded program forks, the child continues running with verification enabled (the tsan background thread is recreated as well)
- if a multi-threaded program forks, then the child runs with verification disabled (memory accesses, atomic operations and interceptors are disabled); it's expected that it will exec soon anyway
- if the child tries to create more threads after multi-threaded fork, the program aborts with error message
- die_after_fork flag is added that allows to continue running, but all bets are off
http://llvm-reviews.chandlerc.com/D2614
llvm-svn: 199993
This change allows to compile sanitizer sources so that *san runtime
will attempt to use libbacktrace and/or libiberty for symbolization
(instead of communicating with llvm-symbolizer).
I've tested this patch by manually defining SANITIZER_LIBBACKTRACE and/or
SANITIZER_CP_DEMANGLE, linking with necessary libraries and verifying that
all tests from ASan test suite work.
Based on patches by Jakub Jelinek!
llvm-svn: 199384
it to the LLVM project through the appropriate channels.
This reverts:
r195837: "[Sanitizer] Add rudimentary support for using libbacktrace in ..."
llvm-svn: 196875
More steps are needed to actually make it usable:
* sanitizer runtimes should be compiled with -DSANITIZER_LIBBACKTRACE.
* libbacktrace headers should be installed.
* user has to manually link in libbacktrace.a into the executable.
We can easily solve the first two problems in the build system, but
detecting/linking libbacktrace to all the tests we have and end-user programs
is more challenging (and will unlikely work w/o Driver support).
Based on the patch by Jakub Jelinek!
llvm-svn: 195837
1) Don't start external symbolizer subprocess until we actually try to
symbolize anything.
2) Allow to turn off external symbolizer by providing empty ?SAN_SYMBOLIZER_PATH
environment variable.
llvm-svn: 195771
Summary:
TSan and MSan need to know if interceptor was called by the
user code or by the symbolizer and use pre- and post-symbolization hooks
for that. Make Symbolizer class responsible for calling these hooks instead.
This would ensure the hooks are only called when necessary (during
in-process symbolization, they are not needed for out-of-process) and
save specific sanitizers from tracing all places in the code where symbolization
will be performed.
Reviewers: eugenis, dvyukov
Reviewed By: eugenis
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D2067
llvm-svn: 193807
This moves away from creating the symbolizer object and initializing the
external symbolizer as separate steps. Those steps now always take place
together.
Sanitizers with a legacy requirement to specify their own symbolizer path
should use InitSymbolizer to initialize the symbolizer with the desired
path, and GetSymbolizer to access the symbolizer. Sanitizers with no
such requirement (e.g. UBSan) can use GetOrInitSymbolizer with no need for
initialization.
The symbolizer interface has been made thread-safe (as far as I can
tell) by protecting its member functions with mutexes.
Finally, the symbolizer interface no longer relies on weak externals, the
introduction of which was probably a mistake on my part.
Differential Revision: http://llvm-reviews.chandlerc.com/D1985
llvm-svn: 193448
Hans Wennborg