Summary:
Adds a version of sigaction that uses a raw system call, to avoid circular
dependencies and support calling sigaction prior to setting up
interceptors. The new sigaction relies on an assembly sigreturn routine
for its restorer, which is Linux x86_64-only for now.
Uses the new sigaction to initialize the working set tool's shadow fault
handler prior to libc interceptor being set up. This is required to
support instrumentation invoked during interceptor setup, which happens
with an instrumented tcmalloc or other allocator compiled with esan.
Adds a test that emulates an instrumented allocator.
Reviewers: aizatsky
Subscribers: vitalybuka, tberghammer, zhaoqin, danalbert, kcc, srhines, eugenis, llvm-commits, kubabrecka
Differential Revision: http://reviews.llvm.org/D21083
llvm-svn: 272591
Summary:
Adds a version of sigaction that uses a raw system call, to avoid circular
dependencies and support calling sigaction prior to setting up
interceptors. The new sigaction relies on an assembly sigreturn routine
for its restorer, which is Linux x86_64-only for now.
Uses the new sigaction to initialize the working set tool's shadow fault
handler prior to libc interceptor being set up. This is required to
support instrumentation invoked during interceptor setup, which happens
with an instrumented tcmalloc or other allocator compiled with esan.
Adds a test that emulates an instrumented allocator.
Reviewers: aizatsky
Subscribers: vitalybuka, tberghammer, zhaoqin, danalbert, kcc, srhines, eugenis, llvm-commits, kubabrecka
Differential Revision: http://reviews.llvm.org/D21083
llvm-svn: 272553
Summary:
Adds a new option -snapshot_step controlling the frequency distribution for
an 8-level series of samples using each bit of each shadow byte.
Implements accumulation from each level to the next higher level at the
specified frequency.
Adds storage of the 8 series of samples using CircularBuffer instances.
Fixes an error in the circular buffer data structure where a static
object's destructor will be called too early.
Prints the results out at the end in a simple manner to give us something
to start with.
Updates the workingset-samples test to test the new feature.
Reviewers: aizatsky
Subscribers: vitalybuka, zhaoqin, kcc, eugenis, llvm-commits, kubabrecka
Differential Revision: http://reviews.llvm.org/D20833
llvm-svn: 271683
Summary:
Adds support for creating a separate thread for performing "sideline"
actions on a periodic basis via an itimer. A new class SidelineThread
implements this feature, exposing a sampling callback to the caller.
Adds initial usage of sideline sampling to the working set tool. For now
it simply prints the usage at each snapshot at verbosity level 1. Adds a
test of this behavior. Adds a new option -record_snapshots to control
whether we sample and a new option -sample_freq to control the periodicity
of the sampling.
Reviewers: aizatsky
Subscribers: vitalybuka, zhaoqin, kcc, eugenis, llvm-commits, kubabrecka
Differential Revision: http://reviews.llvm.org/D20751
llvm-svn: 271682
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
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
Summary:
Adds the base runtime library for the working set tool.
Adds slowpath code for updating the shadow memory.
To be added in the future:
+ Scan memory and report the total size.
+ Take samples for intermediate values.
Reviewers: aizatsky
Subscribers: kubabrecka, vitalybuka, zhaoqin, kcc, eugenis, llvm-commits
Differential Revision: http://reviews.llvm.org/D20485
llvm-svn: 270650
Nico Weber