Commit Graph

4 Commits

Author SHA1 Message Date
Vitaly Buka 3e3f3cf54d [esan] Fix compilation of signal handlers
llvm-svn: 317874
2017-11-10 05:41:13 +00:00
Derek Bruening 34913f3beb [esan|wset] Ensure SIGSEGV is not blocked
Summary:
Adds interception of sigprocmask and pthread_sigmask to esan so that the
working set tool can prevent SIGSEGV from being blocked.  A blocked SIGSEGV
results in crashes due to our lazy shadow page allocation scheme.

Adds new sanitizer helper functions internal_sigemptyset and
internal_sigismember.

Adds a test to workingset-signal-posix.cpp.

Reviewers: aizatsky

Subscribers: vitalybuka, zhaoqin, kcc, eugenis, llvm-commits, kubabrecka

Differential Revision: http://reviews.llvm.org/D22063

llvm-svn: 274672
2016-07-06 21:04:48 +00:00
Derek Bruening 8ef3f0fa5b [esan|wset] Iterate all memory to compute the total working set
Summary:
Adds iteration of all application memory in an efficient manner using
shadow faults.  Shadow memory starts out inaccessible and we mark it
writable one page at a time on each fault when the instrumentation touches
it.  This allows iteration over just the mapped shadow memory, saving
significant time.

Adds a process-end iteration and pretty-printing of the final result.

Adds a new test and updates the existing tests.

Reviewers: aizatsky, filcab

Subscribers: vitalybuka, zhaoqin, kcc, eugenis, llvm-commits, kubabrecka

Differential Revision: http://reviews.llvm.org/D20578

llvm-svn: 271277
2016-05-31 13:41:07 +00:00
Derek Bruening 8e74c1084b [esan] Intercept and chain signal handlers
Summary:
In preparation for fault-based shadow memory iteration, we add support for
our own signal handler by adding app signal handler interception as well as
chaining for SIGSEGV.  This is done in a simple manner: we do not honor the
app's alternate stack nor any sigaction flags for SIGSEGV.

Adds a new test of transparency in app signal handling.

Reviewers: aizatsky

Subscribers: filcab, kubabrecka, vitalybuka, zhaoqin, kcc, eugenis, llvm-commits

Differential Revision: http://reviews.llvm.org/D20577

llvm-svn: 271272
2016-05-31 13:21:03 +00:00