to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Summary:
This change saves and restores the full flags register in x86_64 mode.
This makes running instrumented signal handlers safer, and avoids flags
set during the execution of the event handlers from polluting the
instrumented call's flags state.
Reviewers: kpw, eizan, jfb
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D51277
llvm-svn: 340812
This change adds some assembler comments to facilitate analysis with
llvm-mca. In particular, we're interested in identifying and later
optimising (reducing) the cost of the key functions in the XRay
implementation using both static analysis (with llvm-mca, etc.) and
dynamic analysis (perf profiling, etc.) of microbenchmarks.
llvm-svn: 331711
Summary:
Compiler-rt support first before defining the __xray_typedevent() lowering in
llvm. I'm looking for some early feedback before I touch much more code.
Reviewers: dberris
Subscribers: delcypher, llvm-commits, #sanitizers
Differential Revision: https://reviews.llvm.org/D43668
llvm-svn: 330218
Summary:
This change expands the amount of registers stashed by the entry and
`__xray_CustomEvent` trampolines.
We've found that since the `__xray_CustomEvent` trampoline calls can show up in
situations where the scratch registers are being used, and since we don't
typically want to affect the code-gen around the disabled
`__xray_customevent(...)` intrinsic calls, that we need to save and restore the
state of even the scratch registers in the handling of these custom events.
Reviewers: pcc, pelikan, dblaikie, eizan, kpw, echristo, chandlerc
Reviewed By: echristo
Subscribers: chandlerc, echristo, hiraditya, davide, dblaikie, llvm-commits
Differential Revision: https://reviews.llvm.org/D40894
llvm-svn: 323940
This renames ASM_TSAN_SYMBOL and ASM_TSAN_SYMBOL_INTERCEPTOR to just ASM_SYMBOL and ASM_SYMBOL_INTERCEPTOR, because they can be useful in more places than just TSan. Also introduce a CMake function to add ASM sources to a target.
Differential Revision: https://reviews.llvm.org/D40143
llvm-svn: 319339
This change is the first in a series of changes to get the XRay runtime
building on macOS. This first allows us to build the minimal parts of
XRay to get us started on supporting macOS development. These include:
- CMake changes to allow targeting x86_64 initially.
- Allowing for building the initialisation routines without
`.preinit_array` support.
- Use __sanitizer::SleepForMillis() to work around the lack of
clock_nanosleep on macOS.
- Deprecate the xray_fdr_log_grace_period_us flag, and introduce
the xray_fdr_log_grace_period_ms flag instead, to use
milliseconds across platforms.
Reviewers: kubamracek
Subscribers: llvm-commits, krytarowski, nglevin, mgorny
Differential Review: https://reviews.llvm.org/D39114
llvm-svn: 319165
Summary:
This change fixes the XRay trampolines aside from the __xray_CustomEvent
trampoline to align the stack to 16-byte boundaries before calling the
handler. Before this change we've not been explicitly aligning the stack
to 16-byte boundaries, which makes it dangerous when calling handlers
that leave the stack in a state that isn't strictly 16-byte aligned
after calling the handlers.
We add a test that makes sure we can handle these cases appropriately
after the changes, and prevents us from regressing the state moving
forward.
Fixes http://llvm.org/PR35294.
Reviewers: pelikan, pcc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D40004
llvm-svn: 318261
Summary:
This change implements the changes required in both clang and
compiler-rt to allow building XRay-instrumented binaries in Darwin. For
now we limit this to x86_64. We also start building the XRay runtime
library in compiler-rt for osx.
A caveat to this is that we don't have the tests set up and running
yet, which we'll do in a set of follow-on changes.
This patch uses the monorepo layout for the coordinated change across
multiple projects.
Reviewers: kubamracek
Subscribers: mgorny, cfe-commits, llvm-commits
Differential Revision: https://reviews.llvm.org/D39114
llvm-svn: 317875
Summary:
Write out records about logged function call first arguments. D32840
implements the reading of this in llvm-xray.
Reviewers: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32844
llvm-svn: 314378
Summary:
This change starts differentiating tail exits from normal exits. We also
increase the version number of the "naive" log to version 2, which will
be the starting version where these records start appearing. In FDR mode
we treat the tail exits as normal exits, and are thus subject to the
same treatment with regard to record unwriting.
Updating the version number is important to signal older builds of the
llvm-xray tool that do not deal with the tail exit records must fail
early (and that users should only use the llvm-xray tool built after
the support for tail exits to get accurate handling of these records).
Depends on D37964.
Reviewers: kpw, pelikan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37965
llvm-svn: 313515
Summary:
This change introduces versions to the instrumentation map entries we
emit for XRay instrumentaiton points. The status quo for the version is
currently set to 0 (as emitted by the LLVM back-end), and versions will
count up to 255 (unsigned char).
This change is in preparation for supporting the newer version of the
custom event sleds that will be emitted by the LLVM compiler.
While we're here, we take the opportunity to stash more registers and
align the stack properly in the __xray_CustomEvent trampoline.
Reviewers: kpw, pcc, dblaikie
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D36816
llvm-svn: 311524
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 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
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
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:
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
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
Chandler Carruth