Implement protection against the stack clash attack [0] through inline stack
probing.
Probe stack allocation every PAGE_SIZE during frame lowering or dynamic
allocation to make sure the page guard, if any, is touched when touching the
stack, in a similar manner to GCC[1].
This extends the existing `probe-stack' mechanism with a special value `inline-asm'.
Technically the former uses function call before stack allocation while this
patch provides inlined stack probes and chunk allocation.
Only implemented for x86.
[0] https://www.qualys.com/2017/06/19/stack-clash/stack-clash.txt
[1] https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00556.html
This a recommit of 39f50da2a357a8f685b3540246c5d762734e035f with better option
handling and more portable testing
Differential Revision: https://reviews.llvm.org/D68720
Summary:
Debug Info Version was changed to use "Max" instead of "Warning" per the
original design intent - but this maxes old/new IR unlinkable, since
mismatched merge styles are a linking failure.
It seems possible/maybe reasonable to actually support the combination
of these two flags: Warn, but then use the maximum value rather than the
first value/earlier module's value.
Reviewers: tejohnson
Differential Revision: https://reviews.llvm.org/D74257
Implement protection against the stack clash attack [0] through inline stack
probing.
Probe stack allocation every PAGE_SIZE during frame lowering or dynamic
allocation to make sure the page guard, if any, is touched when touching the
stack, in a similar manner to GCC[1].
This extends the existing `probe-stack' mechanism with a special value `inline-asm'.
Technically the former uses function call before stack allocation while this
patch provides inlined stack probes and chunk allocation.
Only implemented for x86.
[0] https://www.qualys.com/2017/06/19/stack-clash/stack-clash.txt
[1] https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00556.html
This a recommit of 39f50da2a357a8f685b3540246c5d762734e035f with correct option
flags set.
Differential Revision: https://reviews.llvm.org/D68720
This reverts commit 39f50da2a357a8f685b3540246c5d762734e035f.
The -fstack-clash-protection is being passed to the linker too, which
is not intended.
Reverting and fixing that in a later commit.
Implement protection against the stack clash attack [0] through inline stack
probing.
Probe stack allocation every PAGE_SIZE during frame lowering or dynamic
allocation to make sure the page guard, if any, is touched when touching the
stack, in a similar manner to GCC[1].
This extends the existing `probe-stack' mechanism with a special value `inline-asm'.
Technically the former uses function call before stack allocation while this
patch provides inlined stack probes and chunk allocation.
Only implemented for x86.
[0] https://www.qualys.com/2017/06/19/stack-clash/stack-clash.txt
[1] https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00556.html
Differential Revision: https://reviews.llvm.org/D68720
This extends the RemarkStreamer to allow for other emitters (e.g.
frontends, SIL, etc.) to emit remarks through a common interface.
See changes in llvm/docs/Remarks.rst for motivation and design choices.
Differential Revision: https://reviews.llvm.org/D73676
AMDGPU and x86 at least both have separate controls for whether
denormal results are flushed on output, and for whether denormals are
implicitly treated as 0 as an input. The current DAGCombiner use only
really cares about the input treatment of denormals.
Summary:
gnu addr2line prints DWARF line table discriminators like so:
<file>:<line> (discriminator <Number>)
This matches that behavior.
Document how and when --output-style=GNU prints discriminators
Add test for new GNU-style discriminator printing.
Reviewers: rupprecht, labath, jhenderson
Subscribers: aprantl, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73318
Summary:
This is a follow up on D61634. It adds an LLVM IR intrinsic to allow better implementation of memcpy from C++.
A follow up CL will add the intrinsics in Clang.
Reviewers: courbet, theraven, t.p.northover, jdoerfert, tejohnson
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71710
Summary: masked_load and masked_store instructions require the alignment to be specified and a power of two. It seems to me that this requirement applies to masked_gather and masked_scatter as well.
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73179
Summary:
This patch is part of a patch series to add support for FileCheck
numeric expressions. This specific patch adds support for selecting a
matching format to match a numeric value against (ie. decimal, hex lower
case letters or hex upper case letters).
This commit allows to select what format a numeric value should be
matched against. The following formats are supported: decimal value,
lower case hex value and upper case hex value. Matching formats impact
both the format of numeric value to be matched as well as the format of
accepted numbers in a definition with empty numeric expression
constraint.
Default for absence of format is decimal value unless the numeric
expression constraint is non null and use a variable in which case the
format is the one used to define that variable. Conclict of format in
case of several variable being used is diagnosed and forces the user to
select a matching format explicitely.
This commit also enables immediates in numeric expressions to be in any
radix known to StringRef's GetAsInteger method, except for legacy
numeric expressions (ie [[@LINE+<offset>]] which only support decimal
immediates.
Copyright:
- Linaro (changes up to diff 183612 of revision D55940)
- GraphCore (changes in later versions of revision D55940 and
in new revision created off D55940)
Reviewers: jhenderson, chandlerc, jdenny, probinson, grimar, arichardson
Reviewed By: jhenderson, arichardson
Subscribers: daltenty, MaskRay, hiraditya, llvm-commits, probinson, dblaikie, grimar, arichardson, kristina, hfinkel, rogfer01, JonChesterfield
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60389
The sub-heading used to contain the --only-keep-debug switch as that
switch wasn't implemented for ELF at one point. Since the switch is now
in the generic options section, and there are no other options in this
sub-heading, it is pointless and can be deleted.
In LLVM IR, vscale can be represented with an intrinsic. For some targets,
this is equivalent to the constexpr:
getelementptr <vscale x 1 x i8>, <vscale x 1 x i8>* null, i32 1
This can be used to propagate the value in CodeGenPrepare.
In ISel we add a node that can be legalized to one or more
instructions to materialize the runtime vector length.
This patch also adds SVE CodeGen support for VSCALE, which maps this
node to RDVL instructions (for scaled multiples of 16bytes) or CNT[HSD]
instructions (scaled multiples of 2, 4, or 8 bytes, respectively).
Reviewers: rengolin, cameron.mcinally, hfinkel, sebpop, SjoerdMeijer, efriedma, lattner
Reviewed by: efriedma
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68203
Summary:
This commit changes the googlemock link in the Testing Guide doc as googlemock is absorbed into the GoogleTest project
Reviewers: shafik, labath, JDevlieghere, mib
Reviewed By: labath
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73082
These names have been changed from CamelCase to camelCase, but there were
many places (comments mostly) that still used the old names.
This change is NFC.
Currently there are 4 different mechanisms for controlling denormal
flushing behavior, and about as many equivalent frontend controls.
- AMDGPU uses the fp32-denormals and fp64-f16-denormals subtarget features
- NVPTX uses the nvptx-f32ftz attribute
- ARM directly uses the denormal-fp-math attribute
- Other targets indirectly use denormal-fp-math in one DAGCombine
- cl-denorms-are-zero has a corresponding denorms-are-zero attribute
AMDGPU wants a distinct control for f32 flushing from f16/f64, and as
far as I can tell the same is true for NVPTX (based on the attribute
name).
Work on consolidating these into the denormal-fp-math attribute, and a
new type specific denormal-fp-math-f32 variant. Only ARM seems to
support the two different flush modes, so this is overkill for the
other use cases. Ideally we would error on the unsupported
positive-zero mode on other targets from somewhere.
Move the logic for selecting the flush mode into the compiler driver,
instead of handling it in cc1. denormal-fp-math/denormal-fp-math-f32
are now both cc1 flags, but denormal-fp-math-f32 is not yet exposed as
a user flag.
-cl-denorms-are-zero, -fcuda-flush-denormals-to-zero and
-fno-cuda-flush-denormals-to-zero will be mapped to
-fp-denormal-math-f32=ieee or preserve-sign rather than the old
attributes.
Stop emitting the denorms-are-zero attribute for the OpenCL flag. It
has no in-tree users. The meaning would also be target dependent, such
as the AMDGPU choice to treat this as only meaning allow flushing of
f32 and not f16 or f64. The naming is also potentially confusing,
since DAZ in other contexts refers to instructions implicitly treating
input denormals as zero, not necessarily flushing output denormals to
zero.
This also does not attempt to change the behavior for the current
attribute. The LangRef now states that the default is ieee behavior,
but this is inaccurate for the current implementation. The clang
handling is slightly hacky to avoid touching the existing
denormal-fp-math uses. Fixing this will be left for a future patch.
AMDGPU is still using the subtarget feature to control the denormal
mode, but the new attribute are now emitted. A future change will
switch this and remove the subtarget features.
It's been an empty target since r360498 and friends
(`git log --grep='Move InstPrinter files to MCTargetDesc.' llvm/lib/Target`),
but due to hwo the way these targets are structured it was silently
an empty target without anyone noticing.
No behavior change.
This patch updates the formatting and language of the Features section of the
ORCv2 design document. It also fixes a TBD by adding discussion of the
absoluteSymbols, symbolAliases, and reexports utilities.
Typos found during editing were also fixed.
When LLVM_APPEND_VC_REV=OFF is set, the current git hash is no
longer embedded into binaries (mostly for --version output).
Without it, most binaries need to relink after every single
commit, even if they didn't change otherwise (due to, say,
a documentation-only commit).
LLVM_APPEND_VC_REV is ON by default, so this doesn't change the
default behavior of anything.
With this, all clients of GenerateVersionFromVCS.cmake honor
LLVM_APPEND_VC_REV.
Differential Revision: https://reviews.llvm.org/D72855
Summary:
This patch could be treated as a rebase of D33960. It also fixes PR35547.
A fix for `llvm/test/Other/close-stderr.ll` is proposed in D68164. Seems
the consensus is that the test is passing by chance and I'm not
sure how important it is for us. So it is removed like in D33960 for now.
The rest of the test fixes are just adding `--crash` flag to `not` tool.
** The reason it fixes PR35547 is
`exit` does cleanup including calling class destructor whereas `abort`
does not do any cleanup. In multithreading environment such as ThinLTO or JIT,
threads may share states which mostly are ManagedStatic<>. If faulting thread
tearing down a class when another thread is using it, there are chances of
memory corruption. This is bad 1. It will stop error reporting like pretty
stack printer; 2. The memory corruption is distracting and nondeterministic in
terms of error message, and corruption type (depending one the timing, it
could be double free, heap free after use, etc.).
Reviewers: rnk, chandlerc, zturner, sepavloff, MaskRay, espindola
Reviewed By: rnk, MaskRay
Subscribers: wuzish, jholewinski, qcolombet, dschuff, jyknight, emaste, sdardis, nemanjai, jvesely, nhaehnle, sbc100, arichardson, jgravelle-google, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, lenary, s.egerton, pzheng, cfe-commits, MaskRay, filcab, davide, MatzeB, mehdi_amini, hiraditya, steven_wu, dexonsmith, rupprecht, seiya, llvm-commits
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D67847
This updates the discussion of lazy reexports, fixes a TBD for a usage example,
and adds a reference to the fully worked lazy reexports example that was added
in e9e26c01cd865da678b1af6ba5f417c713956a66.
When using the option, draw the histogram representing the debug
location buckets. The resulting histogram will be saved in a png
file.
Differential Revision: https://reviews.llvm.org/D71869
