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:
Testing of XRay was occasionally disabled on 32-bit Arm targets (someone assumed that XRay was supported on 64-bit targets only). This patch should fix that problem. Also here the instruction&data cache incoherency problem is fixed, because it may be causing a test to fail.
This patch is one of a series: see also
- https://reviews.llvm.org/D28624
Reviewers: dberris, rengolin
Reviewed By: rengolin
Subscribers: llvm-commits, aemerson, rengolin, dberris, iid_iunknown
Differential Revision: https://reviews.llvm.org/D28623
llvm-svn: 292517
This reverts commit r292211, as it broke the Thumb buldbot with:
clang-5.0: error: the clang compiler does not support '-fxray-instrument
on thumbv7-unknown-linux-gnueabihf'
llvm-svn: 292356
Summary:
Testing of XRay was occasionally disabled on 32-bit Arm targets (someone assumed that XRay was supported on 64-bit targets only). This patch should fix that problem. Also here the instruction&data cache incoherency problem is fixed, because it may be causing a test to fail.
This patch is one of a series: see also
- https://reviews.llvm.org/D28624
Reviewers: dberris, rengolin
Reviewed By: rengolin
Subscribers: llvm-commits, aemerson, rengolin, dberris, iid_iunknown
Differential Revision: https://reviews.llvm.org/D28623
llvm-svn: 292211
Summary: This patch attempts to fix test patching-unpatching.cc . The new code flushes the instruction cache after modifying the program at runtime.
Reviewers: dberris, rengolin, pelikan, rovka
Subscribers: rovka, llvm-commits, iid_iunknown, aemerson
Differential Revision: https://reviews.llvm.org/D27996
llvm-svn: 291568
Summary:
If you decide to recompile parts of your Linux distro with XRay, it may
be useful to know which trace belongs to which binary. While there, get
rid of the incorrect strncat() usage; it always returns a pointer to the
start which makes that if() always true. Replace with snprintf which is
bounded so that enough from both strings fits nicely.
Reviewers: dberris
Subscribers: danalbert, srhines, kubabrecka, mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D27912
llvm-svn: 290861
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: This patch attempts to fix test patching-unpatching.cc . The new code flushes the instruction cache after modifying the program at runtime.
Reviewers: dberris, rengolin
Subscribers: llvm-commits, iid_iunknown, aemerson
Differential Revision: https://reviews.llvm.org/D27996
llvm-svn: 290452
Summary: This patch attempts to fix test patching-unpatching.cc . The new code flushes the instruction cache after modifying the program at runtime.
Reviewers: dberris, rengolin
Subscribers: llvm-commits, iid_iunknown, aemerson
Differential Revision: https://reviews.llvm.org/D27996
llvm-svn: 290354
Missed a couple of files:
- Using #pragma once
- Missing top-matter for headers
- Missing an include for <cstdint>
Follow-up on D25360.
llvm-svn: 290079
Summary:
Getting rid of the distance number altogether because:
- a person knowledgeable enough to know what the message means will also
know how to do hexadecimal math (with the help of a calculator)
- numbers outside INT_MIN - INT_MAX are hard to comprehend anyway
This unbreaks the case when you dynamically link a library with XRay and
it exits pre-main() with a not very informative static string.
Author: pelikan
Reviewers: dberris
Subscribers: llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D27894
llvm-svn: 290074
projects/compiler-rt/lib/xray/xray_trampoline_x86_64.S:33:7: error: unexpected token in '.endm' directive
.endm SAVE_REGISTERS
^
projects/compiler-rt/lib/xray/xray_trampoline_x86_64.S:52:7: error: unexpected token in '.endm' directive
.endm RESTORE_REGISTERS
^
Remove the trailing name on the `.endm` which does not take the name of the
macro. This should bring the compiler-rt build bot back into working state.
llvm-svn: 289852
Summary:
The layout of all registers saved on stack shouldn't deviate and will be reused in future trampolines as well.
While there, fix whitespace and clarify comments.
Author: mpel
Reviewers: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D27799
llvm-svn: 289789
Summary:
This should improve the error messages generated providing a bit more
information when the failures are printed out. One example of a
contrived error looks like:
```
Expected: (Buffers.getBuffer(Buf)) != (std::error_code()), actual:
system:0 vs system:0
```
Because we're using error codes, the default printing gets us more
useful information in case of failure.
This is a follow-up on D26232.
Reviewers: rSerge
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D27495
llvm-svn: 289501
As constructed before this patch, in case we run into case where we
don't actually build the XRay library, we really ought to not be adding
the unit test runs. This should fix the bootstrap build failures.
This is a follow-up further to D26232.
llvm-svn: 288788
Before this, the change committed in D26232 might have an uninitialised
std::atomic<bool> that may or may not have a valid state. On aarch64
this breaks consistently, while it doesn't manifest as a problem in
x86_64.
This is an attempt to un-break this in aarch64.
llvm-svn: 288776
This implements a simple buffer queue to manage a pre-allocated queue of
fixed-sized buffers to hold XRay records. We need this to support
Flight Data Recorder (FDR) mode. We also implement this as a sub-library
first to allow for development before actually using it in an
implementation.
Some important properties of the buffer queue:
- Thread-safe enqueueing/dequeueing of fixed-size buffers.
- Pre-allocation of buffers at construction.
This is a re-roll of the previous attempt to submit, because it caused
failures in arm and aarch64.
Reviewers: majnemer, echristo, rSerge
Subscribers: tberghammer, danalbert, srhines, modocache, mehdi_amini, mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D26232
llvm-svn: 288775
Summary: Currently test XRay-aarch64-linux::patching-unpatching.cc sometimes passes, sometimes fails. This is an attempt to fix it by handling better the situations when both `__arm__` and `__aarch64__` are defined.
Reviewers: dberris, rengolin
Subscribers: llvm-commits, iid_iunknown, aemerson, rengolin, dberris
Differential Revision: https://reviews.llvm.org/D27421
llvm-svn: 288729
Summary:
This implements a simple buffer queue to manage a pre-allocated queue of
fixed-sized buffers to hold XRay records. We need this to support
Flight Data Recorder (FDR) mode. We also implement this as a sub-library
first to allow for development before actually using it in an
implementation.
Some important properties of the buffer queue:
- Thread-safe enqueueing/dequeueing of fixed-size buffers.
- Pre-allocation of buffers at construction.
Reviewers: majnemer, rSerge, echristo
Subscribers: mehdi_amini, mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D26232
llvm-svn: 287910
This goes through all the calls to `Report(...)` to make sure that each
one would have a newline at the end of the message for readability.
llvm-svn: 287736
Include xray_defs.h in xray_arm.cc (seems to be the only one that doesn't
include it).
Buildbot errors:
[...]/compiler-rt/lib/xray/xray_arm.cc:31:58: error: expected initializer before 'XRAY_NEVER_INSTRUMENT'
inline static uint32_t getMovwMask(const uint32_t Value) XRAY_NEVER_INSTRUMENT {
llvm-svn: 287089
Summary:
Adds a CMake check for whether the compiler used to build the XRay
library supports XRay-instrumentation. If the compiler we're using does
support the `-fxray-instrument` flag (i.e. recently-built Clang), we
define the XRAY_NEVER_INSTRUMENT macro that then makes sure that the
XRay runtime functions never get XRay-instrumented.
This prevents potential weirdness involved with building the XRay
library with a Clang that supports XRay-instrumentation, and is
attempting to XRay-instrument the build of compiler-rt.
Reviewers: majnemer, rSerge, echristo
Subscribers: mehdi_amini, llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D26597
llvm-svn: 287068
Summary:
We define a new trampoline that's a hybrid between the exit and entry
trampolines with the following properties:
- Saves all of the callee-saved registers according to the x86_64
calling conventions.
- Indicate to the log handler function being called that this is a
function exit event.
This fixes a bug that is a result of not saving enough of the register
states, and that the log handler is clobbering registers that would be
used by the function being tail-exited into manifesting as runtime
errors.
Reviewers: rSerge, echristo, majnemer
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D26020
llvm-svn: 285787
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
The definitions in sanitizer_common may conflict with definitions from system headers because:
The runtime includes the system headers after the project headers (as per LLVM coding guidelines).
lib/sanitizer_common/sanitizer_internal_defs.h pollutes the namespace of everything defined after it, which is all/most of the sanitizer .h and .cc files and the included system headers with: using namespace __sanitizer; // NOLINT
This patch solves the problem by introducing the namespace only within the sanitizer namespaces as proposed by Dmitry.
Differential Revision: https://reviews.llvm.org/D21947
llvm-svn: 281657
This patch builds on LLVM r279776.
In this patch I've done some cleanup and abstracted three common steps runtime components have in their CMakeLists files, and added a fourth.
The three steps I abstract are:
(1) Add a top-level target (i.e asan, msan, ...)
(2) Set the target properties for sorting files in IDE generators
(3) Make the compiler-rt target depend on the top-level target
The new step is to check if a command named "runtime_register_component" is defined, and to call it with the component name.
The runtime_register_component command is defined in llvm/runtimes/CMakeLists.txt, and presently just adds the component to a list of sub-components, which later gets used to generate target mappings.
With this patch a new workflow for runtimes builds is supported. The new workflow when building runtimes from the LLVM runtimes directory is:
> cmake [...]
> ninja runtimes-configure
> ninja asan
The "runtimes-configure" target builds all the dependencies for configuring the runtimes projects, and runs CMake on the runtimes projects. Running the runtimes CMake generates a list of targets to bind into the top-level CMake so subsequent build invocations will have access to some of Compiler-RT's targets through the top-level build.
Note: This patch does exclude some top-level targets from compiler-rt libraries because they either don't install files (sanitizer_common), or don't have a cooresponding `check` target (stats).
llvm-svn: 279863
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
Summary:
We also add one test (and the XRay testing infrastructure) to exercise
the patching and unpatching code. This uses the XRay API exported
through the headers as well, installing a custom log handler.
Depends on D23101 for the updated emitted code alignment for the
return/entry sleds.
Reviewers: rSerge, echristo, rnk
Subscribers: tberghammer, danalbert, srhines, mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D23154
llvm-svn: 277971
We now stash and restore the xmm registers in the trampolines so that
log handlers don't need to worry about clobbering these registers.
In response to comments in D21612.
Reviewers: rSerge, eugenis, echristo, rnk
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D23051
llvm-svn: 277683
Dean Michael Berris