Summary:
This change implements support for the custom event logging sleds and
intrinsics at runtime. For now it only supports handling the sleds in
x86_64, with the implementations for other architectures stubbed out to
do nothing.
NOTE: Work in progress, uploaded for exposition/exploration purposes.
Depends on D27503, D30018, and D33032.
Reviewers: echristo, javed.absar, timshen
Subscribers: mehdi_amini, nemanjai, llvm-commits
Differential Revision: https://reviews.llvm.org/D30630
llvm-svn: 302857
Summary:
This change allows us to provide users and implementers of XRay handlers
a means of converting XRay function id's to addresses. This, in
combination with the facilities provided in D32695, allows users to find
out:
- How many function id's there are defined in the current binary.
- Get the address of the function associated with this function id.
- Patch only specific functions according to their requirements.
While we don't directly provide symbolization support in XRay, having
the function's address lets users determine this information easily
either during runtime, or offline with tools like 'addr2line'.
Reviewers: dblaikie, echristo, pelikan
Subscribers: kpw, llvm-commits
Differential Revision: https://reviews.llvm.org/D32846
llvm-svn: 302210
Summary:
This change allows us to patch/unpatch specific functions using the
function ID. This is useful in cases where implementations might want to
do coverage-style, or more fine-grained control of which functions to
patch or un-patch at runtime.
Depends on D32693.
Reviewers: dblaikie, echristo, kpw
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32695
llvm-svn: 302112
This patch allows the Swift compiler to emit calls to `__tsan_external_write` before starting any modifying access, which will cause TSan to detect races on arrays, dictionaries and other classes defined in non-instrumented modules. Races on collections from the Swift standard library and user-defined structs and a frequent cause of subtle bugs and it's important that TSan detects those on top of existing LLVM IR instrumentation, which already detects races in direct memory accesses.
Differential Revision: https://reviews.llvm.org/D31630
llvm-svn: 302050
For a linker init mutex with lazy flag setup
(no __tsan_mutex_create call), it is possible that
no lock/unlock happened before the destroy call.
Then when destroy runs we still don't know that
it is a linker init mutex and will emulate a memory write.
This in turn can lead to false positives as the mutex
is in fact linker initialized.
Support linker init flag in destroy annotation to resolve this.
llvm-svn: 301795
Summary:
In this patch we document the requirements for implementations that want
to install handlers for the dynamically-controlled XRay "framework".
This clarifies what the expectations are for implementations that
want to install their handlers using this API (similar to how the FDR
logging implementation does so). It also gives users some guarantees on
semantics for the APIs.
If all goes well, users can decide to use the XRay APIs to control the
tracing/logging at the application level, without having to depend on
implementation details of the installed logging implementation. This
lets users choose the implementation that comes with compiler-rt, or
potentially multiple other implementations that use the same APIs.
We also add one convenience function (__xray_remove_log_impl()) for
explicitly removing the currently installed log implementation.
Reviewers: kpw, pelikan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32579
llvm-svn: 301784
Summary:
Currently the FDR log writer, upon flushing, dumps a sequence of buffers from
its freelist to disk. A reader can read the first buffer up to an EOB record,
but then it is unclear how far ahead to scan to find the next threads traces.
There are a few ways to handle this problem.
1. The reader has externalized knowledge of the buffer size.
2. The size of buffers is in the file header or otherwise encoded in the log.
3. Only write out the portion of the buffer with records. When released, the
buffers are marked with a size.
4. The reader looks for memory that matches a pattern and synchronizes on it.
2 and 3 seem the most flexible and 2 does not rule 3 out.
This is an implementation of 2.
In addition, the function handler for fdr more aggressively checks for
finalization and makes an attempt to release its buffer.
Reviewers: pelikan, dberris
Reviewed By: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31384
llvm-svn: 298982
Summary:
This change exercises the end-to-end functionality defined in the FDR
logging implementation. We also prepare for being able to run traces
generated by the FDR logging implementation from being analysed with the
llvm-xray command that comes with the LLVM distribution.
This also unblocks D31385, D31384, and D31345.
Reviewers: kpw, pelikan
Subscribers: llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D31452
llvm-svn: 298977
There are several problems with the current annotations (AnnotateRWLockCreate and friends):
- they don't fully support deadlock detection (we need a hook _before_ mutex lock)
- they don't support insertion of random artificial delays to perturb execution (again we need a hook _before_ mutex lock)
- they don't support setting extended mutex attributes like read/write reentrancy (only "linker init" was bolted on)
- they don't support setting mutex attributes if a mutex don't have a "constructor" (e.g. static, Java, Go mutexes)
- they don't ignore synchronization inside of lock/unlock operations which leads to slowdown and false negatives
The new annotations solve of the above problems. See tsan_interface.h for the interface specification and comments.
Reviewed in https://reviews.llvm.org/D31093
llvm-svn: 298809
Summary:
Functions with the LOG_ARGS_ENTRY sled kind at their beginning will be handled
in a way to (optionally) pass their first call argument to your logging handler.
For practical and performance reasons, only the first argument is supported, and
only up to 64 bits.
Reviewers: javed.absar, dberris
Reviewed By: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D29703
llvm-svn: 297000
Summary:
In this change we introduce the notion of a "flight data recorder" mode
for XRay logging, where XRay logs in-memory first, and write out data
on-demand as required (as opposed to the naive implementation that keeps
logging while tracing is "on"). This depends on D26232 where we
implement the core data structure for holding the buffers that threads
will be using to write out records of operation.
This implementation only currently works on x86_64 and depends heavily
on the TSC math to write out smaller records to the inmemory buffers.
Also, this implementation defines two different kinds of records with
different sizes (compared to the current naive implementation): a
MetadataRecord (16 bytes) and a FunctionRecord (8 bytes). MetadataRecord
entries are meant to write out information like the thread ID for which
the metadata record is defined for, whether the execution of a thread
moved to a different CPU, etc. while a FunctionRecord represents the
different kinds of function call entry/exit records we might encounter
in the course of a thread's execution along with a delta from the last
time the logging handler was called.
While this implementation is not exactly what is described in the
original XRay whitepaper, this one gives us an initial implementation
that we can iterate and build upon.
Reviewers: echristo, rSerge, majnemer
Subscribers: mehdi_amini, llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D27038
llvm-svn: 293015
Summary:
In this change we introduce the notion of a "flight data recorder" mode
for XRay logging, where XRay logs in-memory first, and write out data
on-demand as required (as opposed to the naive implementation that keeps
logging while tracing is "on"). This depends on D26232 where we
implement the core data structure for holding the buffers that threads
will be using to write out records of operation.
This implementation only currently works on x86_64 and depends heavily
on the TSC math to write out smaller records to the inmemory buffers.
Also, this implementation defines two different kinds of records with
different sizes (compared to the current naive implementation): a
MetadataRecord (16 bytes) and a FunctionRecord (8 bytes). MetadataRecord
entries are meant to write out information like the thread ID for which
the metadata record is defined for, whether the execution of a thread
moved to a different CPU, etc. while a FunctionRecord represents the
different kinds of function call entry/exit records we might encounter
in the course of a thread's execution along with a delta from the last
time the logging handler was called.
While this implementation is not exactly what is described in the
original XRay whitepaper, this one gives us an initial implementation
that we can iterate and build upon.
Reviewers: echristo, rSerge, majnemer
Subscribers: mehdi_amini, llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D27038
llvm-svn: 290852
Summary: The function computes full module name and coverts pc into offset.
Reviewers: kcc
Subscribers: kubabrecka
Differential Revision: https://reviews.llvm.org/D26820
llvm-svn: 288711
Summary:
This change depends on D23986 which adds tail call-specific sleds. For
now we treat them first as normal exits, and in the future leave room
for implementing this as a different kind of log entry.
The reason for deferring the change is so that we can keep the naive
logging implementation more accurate without additional complexity for
reading the log. The accuracy is gained in effectively interpreting call
stacks like:
A()
B()
C()
Which when tail-call merged will end up not having any exit entries for
A() nor B(), but effectively in turn can be reasoned about as:
A()
B()
C()
Although we lose the fact that A() had called B() then had called C()
with the naive approach, a later iteration that adds the explicit tail
call entries would be a change in the log format and thus necessitate a
version change for the header. We can do this later to have a chance at
releasing some tools (in D21987) that are able to handle the naive log
format, then support higher version numbers of the log format too.
Reviewers: echristo, kcc, rSerge, majnemer
Subscribers: mehdi_amini, llvm-commits, dberris
Differential Revision: https://reviews.llvm.org/D23988
llvm-svn: 284178
This patch extends __sanitizer_finish_switch_fiber method to optionally return previous stack base and size.
This solves the problem of coroutines/fibers library not knowing the original stack context from which the library is used. It's incorrect to assume that such context is always the default stack of current thread (e.g. one such library may be used from a fiber/coroutine created by another library). Bulding a separate stack tracking mechanism would not only duplicate AsanThread, but also require each coroutines/fibers library to integrate with it.
Author: Andrii Grynenko (andriigrynenko)
Reviewed in: https://reviews.llvm.org/D24628
llvm-svn: 282582
Depends on D21612 which implements the building blocks for the compiler-rt
implementation of the XRay runtime. We use a naive in-memory log of fixed-size
entries that get written out to a log file when the buffers are full, and when
the thread exits.
This implementation lays some foundations on to allowing for more complex XRay
records to be written to the log in subsequent changes. It also defines the format
that the function call accounting tool in D21987 will start building upon.
Once D21987 lands, we should be able to start defining more tests using that tool
once the function call accounting tool becomes part of the llvm distribution.
Reviewers: echristo, kcc, rnk, eugenis, majnemer, rSerge
Subscribers: sdardis, rSerge, dberris, tberghammer, danalbert, srhines, majnemer, llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D21982
llvm-svn: 279805
This addresses some comments from D21612, which contains the following changes:
- Update __xray_patch() and __xray_unpatch() API documentation to not imply asynchrony.
- Introduce a scope cleanup mechanism to make sure we can roll-back changes to the XRayPatching global atomic.
- Introduce a few more comments for potential extension points for other platforms (for the implementation details of patching and un-patching).
Reviewers: eugenis, rnk, kcc, echristo, majnemer
Subscribers: llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D22911
llvm-svn: 277124
Summary:
This is a fixed-up version of D21612, to address failure identified post-commit.
Original commit description:
This patch implements the initialisation and patching routines for the XRay runtime, along with the necessary trampolines for function entry/exit handling. For now we only define the basic hooks for allowing an implementation to define a handler that gets run on function entry/exit. We expose a minimal API for controlling the behaviour of the runtime (patching, cleanup, and setting the handler to invoke when instrumenting).
Fixes include:
- Gating XRay build to only Linux x86_64 and with the right dependencies in case it is the only library being built
- Including <cstddef> to fix std::size_t issue
Reviewers: kcc, rnk, echristo
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D22611
llvm-svn: 276251
and also the follow-up "[xray] Only build xray on Linux for now"
Two build errors were reported on the llvm-commits list:
[ 88%] Building CXX object lib/xray/CMakeFiles/clang_rt.xray-x86_64.dir/xray_flags.cc.o
/mnt/b/sanitizer-buildbot1/sanitizer-x86_64-linux/build/llvm/projects/compiler-rt/lib/xray/xray_init.cc:23:10: fatal error: 'llvm/Support/ELF.h' file not found
#include "llvm/Support/ELF.h"
^
and
In file included from /w/src/llvm.org/projects/compiler-rt/lib/xray/xray_interface.cc:16:
/w/src/llvm.org/projects/compiler-rt/lib/xray/xray_interface_internal.h:36:8: error:
no type named 'size_t' in namespace 'std'
std::size_t Entries;
~~~~~^
llvm-svn: 276186
Summary:
This patch implements the initialisation and patching routines for the XRay runtime, along with the necessary trampolines for function entry/exit handling. For now we only define the basic hooks for allowing an implementation to define a handler that gets run on function entry/exit. We expose a minimal API for controlling the behaviour of the runtime (patching, cleanup, and setting the handler to invoke when instrumenting).
Depends on D19904
Reviewers: echristo, kcc, rnk
Subscribers: rnk, mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D21612
llvm-svn: 276117
Adds a new esan public interface routine __esan_get_sample_count() and uses
it to ensure that tests of sampling receive the minimum number of samples.
llvm-svn: 275948
Summary:
This patch is a refactoring of the way cmake 'targets' are grouped.
It won't affect non-UI cmake-generators.
Clang/LLVM are using a structured way to group targets which ease
navigation through Visual Studio UI. The Compiler-RT projects
differ from the way Clang/LLVM are grouping targets.
This patch doesn't contain behavior changes.
Reviewers: kubabrecka, rnk
Subscribers: wang0109, llvm-commits, kubabrecka, chrisha
Differential Revision: http://reviews.llvm.org/D21952
llvm-svn: 275111
Summary:
Adds a new public interface routine __esan_report() which can be used to
request profiling results prior to abnormal termination (e.g., for a server
process killed by its parent where the normal exit does not allow for
normal result reporting).
Implements this for the working-set tool. The cache frag tool is left
unimplemented as it requires missing iteration capabilities.
Adds a new test.
Reviewers: aizatsky
Subscribers: vitalybuka, zhaoqin, kcc, eugenis, llvm-commits, kubabrecka
Differential Revision: http://reviews.llvm.org/D22098
llvm-svn: 274964
This patch adds the __sanitizer_start_switch_fiber and
__sanitizer_finish_switch_fiber methods inspired from what can be found here
2ea64dd249 .
These methods are needed when the compiled software needs to implement
coroutines, fibers or the like. Without a way to annotate them, when the program
jumps to a stack that is not the thread stack, __asan_handle_no_return shows a
warning about that, and the fake stack mechanism may free fake frames that are
still in use.
Author: blastrock (Philippe Daouadi)
Reviewed in http://reviews.llvm.org/D20913
llvm-svn: 273260
Summary:
Merge "exitcode" flag from ASan, LSan, TSan and "exit_code" from MSan
into one entity. Additionally, make sure sanitizer_common now uses the
value of common_flags()->exitcode when dying on error, so that this
flag will automatically work for other sanitizers (UBSan and DFSan) as
well.
User-visible changes:
* "exit_code" MSan runtime flag is now deprecated. If explicitly
specified, this flag will take precedence over "exitcode".
The users are encouraged to migrate to the new version.
* __asan_set_error_exit_code() and __msan_set_exit_code() functions
are removed. With few exceptions, we don't support changing runtime
flags during program execution - we can't make them thread-safe.
The users should use __sanitizer_set_death_callback()
that would call _exit() with proper exit code instead.
* Plugin tools (LSan and UBSan) now inherit the exit code of the parent
tool. In particular, this means that ASan would now crash the program
with exit code "1" instead of "23" if it detects leaks.
Reviewers: kcc, eugenis
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D12120
llvm-svn: 245734
Summary:
Add a weak hook to be called from dfsan's custom memcmp.
The primary user will be lib/Fuzzer.
If this works well we'll add more hooks (strcmp, etc).
Test Plan: Will be covered by lib/Fuzzer tests.
Reviewers: pcc
Reviewed By: pcc
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9541
llvm-svn: 236679
Summary:
Add an interface function which can be used to periodically trigger
leak detection in a long-running process.
NB: The meaning of the kIgnored tag has been changed to allow easy clean-up
between subsequent leak checks. Previously, this tag was applied to explicitly
ignored (i.e. with __lsan_disable() or __lsan_ignore_object()) chunks *and* any
chunks only reachable from those. With this change, it's only applied to
explicitly ignored chunks.
Reviewers: samsonov
Reviewed By: samsonov
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9159
llvm-svn: 235728
Introduce -mllvm -sanitizer-coverage-8bit-counters=1
which adds imprecise thread-unfriendly 8-bit coverage counters.
The run-time library maps these 8-bit counters to 8-bit bitsets in the same way
AFL (http://lcamtuf.coredump.cx/afl/technical_details.txt) does:
counter values are divided into 8 ranges and based on the counter
value one of the bits in the bitset is set.
The AFL ranges are used here: 1, 2, 3, 4-7, 8-15, 16-31, 32-127, 128+.
These counters provide a search heuristic for single-threaded
coverage-guided fuzzers, we do not expect them to be useful for other purposes.
Depending on the value of -fsanitize-coverage=[123] flag,
these counters will be added to the function entry blocks (=1),
every basic block (=2), or every edge (=3).
Use these counters as an optional search heuristic in the Fuzzer library.
Add a test where this heuristic is critical.
llvm-svn: 231166
Reviewed at http://reviews.llvm.org/D4527
Fixed a test case failure on 32-bit Linux, I did right shift on intptr_t, instead it should have been uintptr_t.
llvm-svn: 218538
Reviewed at http://reviews.llvm.org/D4527
This patch is part of an effort to implement a more generic debugging API, as proposed in http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-July/074656.html, with first part reviewed at http://reviews.llvm.org/D4466. Now adding several new APIs: __asan_report_present, __asan_get_report_{pc,bp,sp,address,type,size,description}, __asan_locate_address. These return whether an asan report happened yet, the PC, BP, SP, address, access type (read/write), access size and bug description (e.g. "heap-use-after-free"), __asan_locate_address takes a pointer and tries to locate it, i.e. say whether it is a heap pointer, a global or a stack, or whether it's a pointer into the shadow memory. If global or stack, tries to also return the variable name, address and size. If heap, tries to return the chunk address and size. Generally these should serve as an alternative to "asan_describe_address", which only returns all the data in text form. Having an API to get these data could allow having debugging scripts/extensions that could show additional information about a variable/expression/pointer. Test cases in test/asan/TestCases/debug_locate.cc and test/asan/TestCasea/debug_report.cc.
llvm-svn: 218481
Introduce new public header <sanitizer/allocator_interface.h> and a set
of functions __sanitizer_get_ownership(), __sanitizer_malloc_hook() etc.
that will eventually replace their tool-specific equivalents
(__asan_get_ownership(), __msan_get_ownership() etc.). Tool-specific
functions are now deprecated and implemented as stubs redirecting
to __sanitizer_ versions (which are implemented differently in each tool).
Replace all uses of __xsan_ versions with __sanitizer_ versions in unit
and lit tests.
llvm-svn: 212469
Generalize StackDepot and create a new specialized instance of it to
efficiently (i.e. without duplicating stack trace data) store the
origin history tree.
This reduces memory usage for chained origins roughly by an order of
magnitude.
Most importantly, this new design allows us to put two limits on
stored history data (exposed in MSAN_OPTIONS) that help avoid
exponential growth in used memory on certain workloads.
See comments in lib/msan/msan_origin.h for more details.
llvm-svn: 209284
Summary:
Sandboxed code may now pass additional arguments to
__sanitizer_sandbox_on_notify() to force all coverage data to be dumped to a
single file (the default is one file per module). The user may supply a file or
socket to write to. The latter option can be used to broker out the file writing
functionality. If -1 is passed, we pre-open a file.
llvm-svn: 209121
Add dfsan_set_write_callback(), which sets a callback to be invoked when
a write() call is invoked within DFSan instrumented code.
Patch by Sam Kerner!
Differential Revision: http://reviews.llvm.org/D3268
llvm-svn: 207131
Expose the number of DFSan labels allocated by adding function dfsan_get_label_count().
Patch by Sam Kerner!
Differential Revision: http://llvm-reviews.chandlerc.com/D3109
llvm-svn: 204854
Using __msan_unpoison() on null-terminated strings is awkward because
strlen() can't be called on a poisoned string. This case warrants a special
interface function.
llvm-svn: 204448
Add an interface for telling LSan that a region of memory is to be treated as a
source of live pointers. Useful for code which stores pointers in mapped memory.
llvm-svn: 197489
I still don't know what is causing our bootstrapped LTO buildbots to fail,
but llvm r194701 seems to be OK and I can't imagine that these changes could
cause the problem.
llvm-svn: 194790
Apple's bootstrapped LTO builds have been failing, and these changes (along
with llvm 194701) are the only things on the blamelist. I will either reapply
these changes or help debug the problem, depending on whether this fixes the
buildbots.
llvm-svn: 194779
__sanitizer_set_report_path now accepts two special values - stderr and stdout
logging to other file descriptors is not supported anymore,
it's fragile in presence of multiple processes, fork, etc
llvm-svn: 192706
DataFlowSanitizer is a generalised dynamic data flow analysis.
Unlike other Sanitizer tools, this tool is not designed to detect a
specific class of bugs on its own. Instead, it provides a generic
dynamic data flow analysis framework to be used by clients to help
detect application-specific issues within their own code.
Differential Revision: http://llvm-reviews.chandlerc.com/D967
llvm-svn: 187924
When prelink is installed in the system, prelink-ed
libraries map between 0x003000000000 and 0x004000000000 thus occupying the shadow Gap,
so we need so split the address space even further, like this:
|| [0x10007fff8000, 0x7fffffffffff] || HighMem ||
|| [0x02008fff7000, 0x10007fff7fff] || HighShadow ||
|| [0x004000000000, 0x02008fff6fff] || ShadowGap3 ||
|| [0x003000000000, 0x003fffffffff] || MidMem ||
|| [0x00087fff8000, 0x002fffffffff] || ShadowGap2 ||
|| [0x00067fff8000, 0x00087fff7fff] || MidShadow ||
|| [0x00008fff7000, 0x00067fff7fff] || ShadowGap ||
|| [0x00007fff8000, 0x00008fff6fff] || LowShadow ||
|| [0x000000000000, 0x00007fff7fff] || LowMem ||
Do it only if necessary.
Also added a bit of profiling code to make sure that the
mapping code is efficient.
Added a lit test to simulate prelink-ed libraries.
Unfortunately, this test does not work with binutils-gold linker.
If gold is the default linker the test silently passes.
Also replaced
__has_feature(address_sanitizer)
with
__has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
in two places.
Patch partially by Jakub Jelinek.
llvm-svn: 175263
Moved everything users are not supposed to use to a private interface header.
Documented all public interfaces. Made them safe to use even if built without
MemorySanitizer.
llvm-svn: 173800
library.
These headers are intended to be available to user code when built with
AddressSanitizer (or one of the other sanitizer's in the future) to
interface with the runtime library. As such, they form stable external
C interfaces, and the headers shouldn't be located within the
implementation.
I've pulled them out into what seem like fairly obvious locations and
names, but I'm wide open to further bikeshedding of these names and
locations.
I've updated the code and the build system to cope with the new
locations, both CMake and Makefile. Please let me know if this breaks
anyone's build.
The eventual goal is to install these headers along side the Clang
builtin headers when we build the ASan runtime and install it. My
current thinking is to locate them at:
<prefix>/lib/clang/X.Y/include/sanitizer/common_interface_defs.h
<prefix>/lib/clang/X.Y/include/sanitizer/asan_interface.h
<prefix>/lib/clang/X.Y/include/sanitizer/...
But maybe others have different suggestions?
Fixing the style of the #include between these headers at least unblocks
experimentation with installing them as they now should work when
installed in these locations.
llvm-svn: 162822
Dean Michael Berris