This enabled opaque pointers by default in LLVM. The effect of this
is twofold:
* If IR that contains *neither* explicit ptr nor %T* types is passed
to tools, we will now use opaque pointer mode, unless
-opaque-pointers=0 has been explicitly passed.
* Users of LLVM as a library will now default to opaque pointers.
It is possible to opt-out by calling setOpaquePointers(false) on
LLVMContext.
A cmake option to toggle this default will not be provided. Frontends
or other tools that want to (temporarily) keep using typed pointers
should disable opaque pointers via LLVMContext.
Differential Revision: https://reviews.llvm.org/D126689
When building with debug info enabled, some load/store instructions do
not have a DebugLocation attached. When using the default IRBuilder, it
attempts to copy the DebugLocation from the insertion-point instruction.
When there's no DebugLocation, no attempt is made to add one.
This is problematic for inserted calls, where the enclosing function has
debug info but the call ends up without a DebugLocation in e.g. LTO
builds that verify that both the enclosing function and calls to
inlinable functions have debug info attached.
This issue was noticed in Linux kernel KCSAN builds with LTO and debug
info enabled:
| ...
| inlinable function call in a function with debug info must have a !dbg location
| call void @__tsan_read8(i8* %432)
| ...
To fix, ensure that all calls to the runtime have a DebugLocation
attached, where the possibility exists that the insertion-point might
not have any DebugLocation attached to it.
Reviewed By: nickdesaulniers
Differential Revision: https://reviews.llvm.org/D124937
This patch switches the PGO implementation on AIX from using the runtime
registration-based section tracking to the __start_SECNAME/__stop_SECNAME
based. In order to enable the recognition of __start_SECNAME/__stop_SECNAME
symbols in the AIX linker, the -bdbg:namedsects:ss needs to be used.
Reviewed By: jsji, MaskRay, davidxl
Differential Revision: https://reviews.llvm.org/D124857
We don't need to insert a load of the dynamic shadow address unless there
are interesting memory accesses to profile.
Split out of D124703.
Differential Revision: https://reviews.llvm.org/D124797
Suppress instrumentation of PGO counter accesses, which is unnecessary
and costly. Also suppress accesses to other compiler inserted variables
starting with "__llvm". This is a slightly expanded variant of what is
done for tsan in shouldInstrumentReadWriteFromAddress.
Differential Revision: https://reviews.llvm.org/D124703
With the -enable-new-pm defaulting to true, the two forms have the same effect,
but the previous form uses the legacy pass manager syntax which is being phased
out.
Revert "[docs] Fix underline"
Breaks a lot of asan tests in google.
This reverts commit 365c3e85bced1fb56c2d94adc34bff7a94abe4a6.
This reverts commit 78a784bea443cdcecf894155ab37893d7a8e8332.
This emits an `st_size` that represents the actual useable size of an object before the redzone is added.
Reviewed By: vitalybuka, MaskRay, hctim
Differential Revision: https://reviews.llvm.org/D123010
This can cause crashes by accidentally optimizing out checks for
extern_weak_func != nullptr, when replaced with a known-not-null wrapper.
This solution isn't perfect (only avoids replacement on specific patterns)
but should address common cases.
Internal reference: b/185245029
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D123701
LTO objects might compiled with different `mbranch-protection` flags which will cause an error in the linker.
Such a setup is allowed in the normal build with this change that is possible.
Reviewed By: pcc
Differential Revision: https://reviews.llvm.org/D123493
We need to explicitly query the shadow here, because it is lazily
initialized for byval arguments. Without opaque pointers this used to
mostly work out, because there would be a bitcast to `i8*` present, and
that would query, and copy in case of byval, the argument shadow.
Reviewed By: vitalybuka, eugenis
Differential Revision: https://reviews.llvm.org/D123602
We need to explicitly query the shadow here, because it is lazily
initialized for byval arguments. Without opaque pointers this used to
mostly work out, because there would be a bitcast to `i8*` present, and
that would query, and copy in case of byval, the argument shadow.
Reviewed By: vitalybuka, eugenis
Differential Revision: https://reviews.llvm.org/D123602
Allow receiving memcpy/memset/memmove instrumentation by using __asan or
__hwasan prefixed versions for AddressSanitizer and HWAddressSanitizer
respectively when compiling in kernel mode, by passing params
-asan-kernel-mem-intrinsic-prefix or -hwasan-kernel-mem-intrinsic-prefix.
By default the kernel-specialized versions of both passes drop the
prefixes for calls generated by memintrinsics. This assumes that all
locations that can lower the intrinsics to libcalls can safely be
instrumented. This unfortunately is not the case when implicit calls to
memintrinsics are inserted by the compiler in no_sanitize functions [1].
To solve the issue, normal memcpy/memset/memmove need to be
uninstrumented, and instrumented code should instead use the prefixed
versions. This also aligns with ASan behaviour in user space.
[1] https://lore.kernel.org/lkml/Yj2yYFloadFobRPx@lakrids/
Reviewed By: glider
Differential Revision: https://reviews.llvm.org/D122724
NVPTX does not support generating binary files, which is required for
these tests.
The majority of tests in 'DebugInfo/Generic' also require emitting
object files, so they all are disabled for NVPTX.
Differential Revision: https://reviews.llvm.org/D121996
Quote from the LLVM Language Reference
If ptr is a stack-allocated object and it points to the first byte of the
object, the object is initially marked as dead. ptr is conservatively
considered as a non-stack-allocated object if the stack coloring algorithm
that is used in the optimization pipeline cannot conclude that ptr is a
stack-allocated object.
By replacing the alloca pointer with the tagged address before this change,
we confused the stack coloring algorithm.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D121835
Failed on buildbot:
/home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/bin/llc: error: : error: unable to get target for 'aarch64-unknown-linux-android29', see --version and --triple.
FileCheck error: '<stdin>' is empty.
FileCheck command line: /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/bin/FileCheck /home/buildbot/buildbot-root/llvm-project/llvm/test/Instrumentation/HWAddressSanitizer/stack-coloring.ll --check-prefix=COLOR
This reverts commit 208b923e74feeb986fe5114ca39a74b1d2032ed7.
Quote from the LLVM Language Reference
If ptr is a stack-allocated object and it points to the first byte of the
object, the object is initially marked as dead. ptr is conservatively
considered as a non-stack-allocated object if the stack coloring algorithm
that is used in the optimization pipeline cannot conclude that ptr is a
stack-allocated object.
By replacing the alloca pointer with the tagged address before this change,
we confused the stack coloring algorithm.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D121835
This relands commit 731347431976509823e38329a96fcbc69fe98cd2.
It failed on Windows/Mac because `-fjmc` is only checked for ELF targets.
Check the flag unconditionally instead and issue a warning for non-ELF targets.
Currently, when instrumenting indirect calls, this uses
CallBase::getCalledFunction to determine whether a given callsite is
eligible.
However, that returns null if:
this is an indirect function invocation or the function signature
does not match the call signature.
So, we end up instrumenting direct calls where the callee is a bitcast
ConstantExpr, even though we presumably don't need to.
Use isIndirectCall to ignore those funky direct calls.
Differential Revision: https://reviews.llvm.org/D119594
The motivation is to enable the MSVC-style JMC instrumentation usable by a ELF-based
debugger. Since there is no prior experience implementing JMC feature for ELF-based
debugger, it might be better to just reuse existing MSVC-style JMC instrumentation.
For debuggers that support both ELF&COFF (like lldb), the JMC implementation might
be shared between ELF&COFF. If this is found to inadequate, it is pretty low-cost
switching to alternatives.
Implementation:
- The '-fjmc' is already a driver and cc1 flag. Wire it up for ELF in the driver.
- Refactor the JMC instrumentation pass a little bit.
- The ELF handling is different from MSVC in two places:
* the flag section name is ".just.my.code" instead of ".msvcjmc"
* the way default function is provided: MSVC uses /alternatename; ELF uses weak function.
Based on D118428.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D119910
Currently adding attribute no_sanitize("bounds") isn't disabling
-fsanitize=local-bounds (also enabled in -fsanitize=bounds). The Clang
frontend handles fsanitize=array-bounds which can already be disabled by
no_sanitize("bounds"). However, instrumentation added by the
BoundsChecking pass in the middle-end cannot be disabled by the
attribute.
The fix is very similar to D102772 that added the ability to selectively
disable sanitizer pass on certain functions.
In this patch, if no_sanitize("bounds") is provided, an additional
function attribute (NoSanitizeBounds) is attached to IR to let the
BoundsChecking pass know we want to disable local-bounds checking. In
order to support this feature, the IR is extended (similar to D102772)
to make Clang able to preserve the information and let BoundsChecking
pass know bounds checking is disabled for certain function.
Reviewed By: melver
Differential Revision: https://reviews.llvm.org/D119816
This is a clean-up patch. The functional pass was rolled into the module pass in D112732.
Reviewed By: vitalybuka, aeubanks
Differential Revision: https://reviews.llvm.org/D120674
For ASan this will effectively serve as a synonym for
__attribute__((no_sanitize("address"))).
Adding the disable_sanitizer_instrumentation to functions will drop the
sanitize_XXX attributes on the IR level.
This is the third reland of https://reviews.llvm.org/D114421.
Now that TSan test is fixed (https://reviews.llvm.org/D120050) there
should be no deadlocks.
Differential Revision: https://reviews.llvm.org/D120055
We have the `clang -cc1` command-line option `-funwind-tables=1|2` and
the codegen option `VALUE_CODEGENOPT(UnwindTables, 2, 0) ///< Unwind
tables (1) or asynchronous unwind tables (2)`. However, this is
encoded in LLVM IR by the presence or the absence of the `uwtable`
attribute, i.e. we lose the information whether to generate want just
some unwind tables or asynchronous unwind tables.
Asynchronous unwind tables take more space in the runtime image, I'd
estimate something like 80-90% more, as the difference is adding
roughly the same number of CFI directives as for prologues, only a bit
simpler (e.g. `.cfi_offset reg, off` vs. `.cfi_restore reg`). Or even
more, if you consider tail duplication of epilogue blocks.
Asynchronous unwind tables could also restrict code generation to
having only a finite number of frame pointer adjustments (an example
of *not* having a finite number of `SP` adjustments is on AArch64 when
untagging the stack (MTE) in some cases the compiler can modify `SP`
in a loop).
Having the CFI precise up to an instruction generally also means one
cannot bundle together CFI instructions once the prologue is done,
they need to be interspersed with ordinary instructions, which means
extra `DW_CFA_advance_loc` commands, further increasing the unwind
tables size.
That is to say, async unwind tables impose a non-negligible overhead,
yet for the most common use cases (like C++ exceptions), they are not
even needed.
This patch extends the `uwtable` attribute with an optional
value:
- `uwtable` (default to `async`)
- `uwtable(sync)`, synchronous unwind tables
- `uwtable(async)`, asynchronous (instruction precise) unwind tables
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D114543
