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 bug is caused by the incorrect handling of return-value registers.
According to OpenPOWER 64-Bit ELF V2 ABI 2.2.5, up to 2 general-purpose
registers are going to be used for return values, and up to 8 floating
point registers or vector registers are going to be used for return
values.
Reviewers: dberris, echristo
Subscribers: nemanjai, llvm-commits
Differential Revision: https://reviews.llvm.org/D33027
llvm-svn: 302691
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
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:
This is a follow-up to D32202.
While the previous change (D32202) did fix the stack alignment issue, we
were still at a weird state in terms of the CFI/CFA directives (as the
offsets were wrong). This change cleans up the SAVE/RESTORE macros for
the trampoline, accounting the stack pointer adjustments with less
instructions and with some clearer math. We note that the offsets will
be different on the exit trampolines, because we don't typically 'call'
into this trampoline and we only ever jump into them (i.e. treated as a
tail call that's patched in at runtime).
Reviewers: eugenis, kpw, pelikan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32214
llvm-svn: 300815
Summary:
Previously, we had been very undisciplined about CFI annotations with
the XRay trampolines. This leads to runtime crashes due to mis-alined
stack pointers that some function implementations may run into (i.e.
those using instructions that require properly aligned addresses coming
from the stack). This patch attempts to clean that up, as well as more
accurately use the correct amounts of space on the stack for stashing
and un-stashing registers.
Reviewers: eugenis, kcc
Subscribers: kpw, llvm-commits
Differential Revision: https://reviews.llvm.org/D32202
llvm-svn: 300660
A problem arises if a machine supports the rdtscp instruction, but the processor
frequency cannot be determined by the function getTSCFrequency(). In this case,
we want to use the emulated TSC instead. This patch implements that by adding a
call to getTSCFrequency() from probeRequiredCPUFeatures(), and the function only
returns true if both the processor supports rdtscp and the CPU frequency can be
determined.
This should fix PR32620.
Reviewers: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32067
llvm-svn: 300525
Summary:
While there, make the threshold in ticks for the rewind computed only
once and not per function, unify the two versions we had and slightly
reformat bits according to coding standards.
Reviewers: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31971
llvm-svn: 300028
Summary:
Not repeating screamy failure paths makes the 300+ line function a bit shorter.
There's no need to overload the variable name "Buffer" if it only works on the
thread local buffer. Fix some comments while there.
I plan to move the rewinding logic into a separate function too, but in this
diff it would be too much of a mess to comprehend. This is trivially NFC.
Reviewers: kpw, dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31930
llvm-svn: 300018
This patch applies a work-around to the XRay FDR tests when TSC emulation is
needed because the processor frequency cannot be determined.
This fixes PR32620 using the suggestion given by Dean in comment 1.
Reviewers: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31967
llvm-svn: 300017
Previously in r297800, a work-around was created to use TSC emulation on x86_64 when RDTSCP was not available on the host. A similar change was needed in the file xray_fdr_logging.cc which this patch ports over to that file.
Eventually the code should be refactored as there will be 3 locations with the same code, but that can be done as a separate step. This patch is just to keep the test from failing on my machine due to an illegal instruction since RDTSCP is not available on my x86_64 linux VM.
Reviewers: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31909
llvm-svn: 299922
Summary:
We can move this functionality into LLVM's tools instead, as it no
longer is strictly required for the compiler-rt testing infrastructure.
It also is blocking the successful bootstrapping of the clang compiler
due to a missing virtual destructor in one of the flag parsing library.
Since this binary isn't critical for the XRay runtime testing effort
anymore (yet), we remove it in the meantime with the hope of moving the
functionality in LLVM proper instead.
Reviewers: kpw, pelikan, rnk, seurer, eugenis
Subscribers: llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D31926
llvm-svn: 299916
Summary:
"short" is defined as an xray flag, and buffer rewinding happens for both exits
and tail exits.
I've made the choice to seek backwards finding pairs of FunctionEntry, TailExit
record pairs and erasing them if the FunctionEntry occurred before exit from the
currently exiting function. This is a compromise so that we don't skip logging
tail calls if the function that they call into takes longer our duration.
This works by counting the consecutive function and function entry, tail exit
pairs that proceed the current point in the buffer. The buffer is rewound to
check whether these entry points happened recently enough to be erased.
It is still possible we will omit them if they call into a child function that
is not instrumented which calls a fast grandchild that is instrumented before
doing other processing.
Reviewers: pelikan, dberris
Reviewed By: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31345
llvm-svn: 299629
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
In file included from /home/abuild/rpmbuild/BUILD/llvm/projects/compiler-rt/lib/xray/tests/unit/xray_fdr_log_printer_tool.cc:15:
../projects/compiler-rt/lib/xray/tests/../xray_fdr_logging_impl.h:221:21: error: use of undeclared identifier 'CLOCK_MONOTONIC'
wall_clock_reader(CLOCK_MONOTONIC, &TS);
^
1 error generated.
llvm-svn: 298837
Instead of std::atomic APIs for atomic operations, we instead use APIs
include with sanitizer_common. This allows us to, at runtime, not have
to depend on potentially dynamically provided implementations of these
atomic operations.
Fixes http://llvm.org/PR32274.
llvm-svn: 298833
Summary: Fd needs to be closed before the number gets out of scope.
Reviewers: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31278
llvm-svn: 298685
Summary:
Depending on C++11 <system_error> introduces a link-time requirement to
C++11 symbols. Removing it allows us to depend on header-only C++11 and
up libraries.
Partially fixes http://llvm.org/PR32274 -- we know there's more invasive work
to be done, but we're doing it incrementally.
Reviewers: dblaikie, kpw, pelikan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31233
llvm-svn: 298480
Summary:
Separated the IO and the thread local storage state machine of logging
from the writing of log records once the contents are deterministic.
Finer granularity functions are provided as inline functions in the same
header such that stack does not grow due to the functions being separated.
An executable utility xray_fdr_log_printer is also implemented to use the
finest granularity functions to produce binary test data in the FDR format
with a relatively convenient text input.
For example, one can take a file with textual contents layed out in rows
and feed it to the binary to generate data that llvm-xray convert can then
read. This is a convenient way to build a test suite for llvm-xray convert
to ensure it's robust to the fdr format.
Example:
$cat myFile.txt
NewBuffer : { time = 2 , Tid=5}
NewCPU : { CPU =1 , TSC = 123}
Function : { FuncId = 5, TSCDelta = 3, EntryType = Entry }
Function : { FuncId = 5, TSCDelta = 5, EntryType = Exit}
TSCWrap : { TSC = 678 }
Function : { FuncId = 6, TSCDelta = 0, EntryType = Entry }
Function : { FuncId = 6, TSCDelta = 50, EntryType = Exit }
EOB : { }
$cat myFile.txt | ./bin/xray_fdr_log_printer > /tmp/binarydata.bin
$./bin/llvm-xray convert -output-format=yaml -output=- /tmp/binarydata.bin
yaml format comes out as expected.
Reviewers: dberris, pelikan
Reviewed By: dberris
Subscribers: llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D30850
llvm-svn: 297801
Summary:
Use TSC emulation in cases where RDTSCP isn't available on the host
running an XRay instrumented binary. We can then fall back into
emulation instead of not even installing XRay's runtime functionality.
We only do this for now in the naive/basic logging implementation, but
should be useful in even FDR mode.
Should fix http://llvm.org/PR32148.
Reviewers: pelikan, rnk, sdardis
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D30677
llvm-svn: 297800
rL297000 forgot to include code for three architectures that appeared
since I wrote the first version. This gives them the same treatment as ARMs
have for now - write stubs and wait for someone to actually implement it.
Patched by pelikan (Martin Pelikán)!
Differential Revision: https://reviews.llvm.org/D30634
llvm-svn: 297003
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:
Use a common definition of a "this variable is unused" annotation for useless
variables only present for their lambda global initializers, to silence gcc's
warning.
Reviewers: dberris
Reviewed By: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D29860
llvm-svn: 296449
Summary:
Currently, we assume that applications built with XRay would like to
have the instrumentation sleds patched before main starts. This patch
changes the default so that we do not patch the instrumentation sleds
before main. This default is more helpful for deploying applications in
environments where changing the current default is harder (i.e. on
remote machines, or work-pool-like systems).
This default (not to patch pre-main) makes it easier to selectively run
applications with XRay instrumentation enabled, than with the current
state.
Reviewers: echristo, timshen
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D30396
llvm-svn: 296445
Summary:
Currently, defaulted options cannot be overriden easily. As an example,
we always patch the binary pre-main unless the user defines the option
at the commandline to inhibit this behaviour. This change allows for
building different versions of the XRay archive with different defaults
(whether to patch pre-main, or whether to use FDR mode by default, etc.)
and giving that choice at link-time.
For now we don't create different archives that have different defaults,
but those could be added in later revisions. This change just enables
the possibility.
Reviewers: pelikan, kcc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D30022
llvm-svn: 295534
Revert "Fix -Wsign-compare - this might not be quite right, but preserves behavior"
Revert "[XRay] Implement powerpc64le xray."
This reverts commit r294826.
This reverts commit r294781.
llvm-svn: 294842
Summary:
powerpc64 big-endian is not supported, but I believe that most logic can
be shared, except for xray_powerpc64.cc.
Also add a function InvalidateInstructionCache to xray_util.h, which is
copied from llvm/Support/Memory.cpp. I'm not sure if I need to add a unittest,
and I don't know how.
Reviewers: dberris, echristo, iteratee, kbarton, hfinkel
Subscribers: mehdi_amini, nemanjai, mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D29742
llvm-svn: 294781
Summary:
The implementation, however, is in different arch-specific files, unless it's emulated.
Reviewers: dberris, pelikan, javed.absar
Subscribers: aemerson, llvm-commits
Differential Revision: https://reviews.llvm.org/D29796
llvm-svn: 294777
Summary:
Fixing a bug I found when testing a reader for the FDR format. Function ID is
now correctly packed into the 28 bits which are documented for it instead of being
masked to all ones.
Reviewers: dberris, pelikan, eugenis
Reviewed By: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D29698
llvm-svn: 294563
Summary:
As pointed out in casual reading of the XRay codebase, that we had
some interesting named functions that didn't quite follow the LLVM coding
conventions.
Reviewers: chandlerc, dblaikie
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D29625
llvm-svn: 294373
Summary:
This was pointed out that FDR mode didn't quite put the thread ID in the
buffers, but instead would write down the parent process ID.
Reviewers: pelikan, rSerge
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D29484
llvm-svn: 294166
Summary:
In llvm.org/PR31756 it's pointed out that sometimes rdtscp isn't
available. We fix it here by checking first whether it's availble before
installing the logging handler. In future commits we can have
alternative implementations, maybe working around some of the
constraints on some systems.
This change enables us to make that determination, but report an error
instead when the features aren't available.
Reviewers: sdardis, javed.absar, rSerge
Subscribers: pelikan, llvm-commits
Differential Revision: https://reviews.llvm.org/D29438
llvm-svn: 293870
Summary:
This patch provides more staging for tail calls in XRay Arm32 . When the logging part of XRay is ready for tail calls, its support in the core part of XRay Arm32 may be as easy as changing the number passed to the handler from 1 to 2.
Coupled patch:
- https://reviews.llvm.org/D28673
Reviewers: dberris, rengolin
Reviewed By: dberris, rengolin
Subscribers: llvm-commits, iid_iunknown, aemerson
Differential Revision: https://reviews.llvm.org/D28674
llvm-svn: 293186
Summary:
This patch provides a trampoline for function tail exit tracing. Still, it's staging because code `1` is passed to the handler function (indicating a normal exit) instead of `2`, which would indicate tail exit. This is so until the logging part of XRay supports tail exits too.
Related: https://reviews.llvm.org/D28947 (LLVM)
Reviewers: dberris, rengolin
Reviewed By: rengolin
Subscribers: aemerson, llvm-commits, iid_iunknown
Differential Revision: https://reviews.llvm.org/D28948
llvm-svn: 293082
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
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
Dean Michael Berris