This removes an abuse of ELF linker behaviors while keeping Mach-O/COFF linker
behaviors unchanged.
ELF: when module_ctor is in a comdat, this patch removes reliance on a linker
abuse (an SHT_INIT_ARRAY in a section group retains the whole group) by using
SHF_GNU_RETAIN. No linker behavior difference when module_ctor is not in a comdat.
Mach-O: module_ctor gets `N_NO_DEAD_STRIP`. No linker behavior difference
because module_ctor is already referenced by a `S_MOD_INIT_FUNC_POINTERS`
section (GC root).
PE/COFF: no-op. SanitizerCoverage already appends module_ctor to `llvm.used`.
Other sanitizers: llvm.used for local linkage is not implemented in
`TargetLoweringObjectFileCOFF::emitLinkerDirectives` (once implemented or
switched to a non-local linkage, COFF can use module_ctor in comdat (i.e.
generalize ELF-specific rL301586)).
There is no object file size difference.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D106246
In the textual format, `noduplicates` means no COMDAT/section group
deduplication is performed. Therefore, if both sets of sections are retained, and
they happen to define strong external symbols with the same names,
there will be a duplicate definition linker error.
In PE/COFF, the selection kind lowers to `IMAGE_COMDAT_SELECT_NODUPLICATES`.
The name describes the corollary instead of the immediate semantics. The name
can cause confusion to other binary formats (ELF, wasm) which have implemented/
want to implement the "no deduplication" selection kind. Rename it to be clearer.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D106319
We need the compiler generated variable to override the weak symbol of
the same name inside the profile runtime, but using LinkOnceODRLinkage
results in weak symbol being emitted in which case the symbol selected
by the linker is going to depend on the order of inputs which can be
fragile.
This change replaces the use of weak definition inside the runtime with
a weak alias. We place the compiler generated symbol inside a COMDAT
group so dead definition can be garbage collected by the linker.
We also disable the use of runtime counter relocation on Darwin since
Mach-O doesn't support weak external references, but Darwin already uses
a different continous mode that relies on overmapping so runtime counter
relocation isn't needed there.
Differential Revision: https://reviews.llvm.org/D105176
SystemZ ABI requires zero-extending function parameters to 64-bit. The
compiler is free to optimize the code around this assumption, e.g.
failing to zero-extend __tsan_atomic32_load()'s morder may cause
crashes in to_mo() switch table lookup.
Fix by adding zeroext attributes to TSan's FunctionCallees, similar to
how it was done in commit 3bc439bdff8b ("[MSan] Add instrumentation for
SystemZ"). This is a no-op on arches that don't need it.
Reviewed By: dvyukov
Differential Revision: https://reviews.llvm.org/D105629
This patch fixes code that incorrectly handled dbg.values with duplicate
location operands, i.e. !DIArgList(i32 %a, i32 %a). The errors in
question were caused by either applying an update to dbg.value multiple
times when the update is only valid once, or by updating the
DIExpression for only the first instance of a value that appears
multiple times.
Differential Revision: https://reviews.llvm.org/D105831
This patch fixes an issue which occurred in CodeGenPrepare and
HWAddressSanitizer, which both at some point create a map of Old->New
instructions and update dbg.value uses of these. They did this by
iterating over the dbg.value's location operands, and if an instance of
the old instruction was found, replaceVariableLocationOp would be
called on that dbg.value. This would cause an error if the same operand
appeared multiple times as a location operand, as the first call to
replaceVariableLocationOp would update all uses of the old instruction,
invalidating the old iterator and eventually hitting an assertion.
This has been fixed by no longer iterating over the dbg.value's location
operands directly, but by first collecting them into a set and then
iterating over that, ensuring that we never attempt to replace a
duplicated operand multiple times.
Differential Revision: https://reviews.llvm.org/D105129
Same as other CreateLoad-style APIs, these need an explicit type
argument to support opaque pointers.
Differential Revision: https://reviews.llvm.org/D105395
We need the compiler generated variable to override the weak symbol of
the same name inside the profile runtime, but using LinkOnceODRLinkage
results in weak symbol being emitted which leads to an issue where the
linker might choose either of the weak symbols potentially disabling the
runtime counter relocation.
This change replaces the use of weak definition inside the runtime with
an external weak reference to address the issue. We also place the
compiler generated symbol inside a COMDAT group so dead definition can
be garbage collected by the linker.
Differential Revision: https://reviews.llvm.org/D105176
This allows application code checks if origin tracking is on before
printing out traces.
-dfsan-track-origins can be 0,1,2.
The current code only distinguishes 1 and 2 in compile time, but not at runtime.
Made runtime distinguish 1 and 2 too.
Reviewed By: browneee
Differential Revision: https://reviews.llvm.org/D105128
The code was previously relying on the fact that an incorrectly
typed global would result in the insertion of a BitCast constant
expression. With opaque pointers, this is no longer the case, so
we should check the type explicitly.
This enable no_sanitize C++ attribute to exclude globals from hwasan
testing, and automatically excludes other sanitizers' globals (such as
ubsan location descriptors).
Differential Revision: https://reviews.llvm.org/D104825
On ELF, the D1003372 optimization can apply to more cases. There are two
prerequisites for making `__profd_` private:
* `__profc_` keeps `__profd_` live under compiler/linker GC
* `__profd_` is not referenced by code
The first is satisfied because all counters/data are in a section group (either
`comdat any` or `comdat noduplicates`). The second requires that the function
does not use value profiling.
Regarding the second point: `__profd_` may be referenced by other text sections
due to inlining. There will be a linker error if a prevailing text section
references the non-prevailing local symbol.
With this change, a stage 2 (`-DLLVM_TARGETS_TO_BUILD=X86 -DLLVM_BUILD_INSTRUMENTED=IR`)
clang is 4.2% smaller (1-169620032/177066968).
`stat -c %s **/*.o | awk '{s+=$1}END{print s}' is 2.5% smaller.
Reviewed By: davidxl, rnk
Differential Revision: https://reviews.llvm.org/D103717
These other platforms are unsupported and untested.
They could be re-added later based on MSan code.
Reviewed By: gbalats, stephan.yichao.zhao
Differential Revision: https://reviews.llvm.org/D104481
This reverts commit 76d0747e0807307780ba84cbd7e5c80b20c26bd7.
If a group has `__llvm_prf_vals` due to static value profiler counters
(`NS!=0`), we cannot make `__llvm_prf_data` private, because a prevailing text
section may reference `__llvm_prf_data` and will cause a `relocation refers to a
discarded section` linker error.
Note: while a `__profc_` group is non-prevailing, it may be referenced by a
prevailing text section due to inlining.
```
group section [ 66] `.group' [__profc__ZN5clang20EmitClangDeclContextERN4llvm12RecordKeeperERNS0_11raw_ostreamE] contains 4 sections:
[Index] Name
[ 67] __llvm_prf_cnts
[ 68] __llvm_prf_vals
[ 69] __llvm_prf_data
[ 70] .rela__llvm_prf_data
```
The current naming scheme adds the `dfs$` prefix to all
DFSan-instrumented functions. This breaks mangling and prevents stack
trace printers and other tools from automatically demangling function
names.
This new naming scheme is mangling-compatible, with the `.dfsan`
suffix being a vendor-specific suffix:
https://itanium-cxx-abi.github.io/cxx-abi/abi.html#mangling-structure
With this fix, demangling utils would work out-of-the-box.
Reviewed By: stephan.yichao.zhao
Differential Revision: https://reviews.llvm.org/D104494
For ELF, since all counters/data are in a section group (either `comdat any` or
`comdat noduplicates`), and the signature for `comdat any` is `__profc_`, the
D1003372 optimization prerequisite (linker GC cannot discard data variables
while the text section is retained) is always satisified, we can make __profd_
unconditionally private.
Reviewed By: davidxl, rnk
Differential Revision: https://reviews.llvm.org/D103717
These other platforms are unsupported and untested.
They could be re-added later based on MSan code.
Reviewed By: gbalats, stephan.yichao.zhao
Differential Revision: https://reviews.llvm.org/D104481
This patch is to address https://bugs.llvm.org/show_bug.cgi?id=50610.
In computed goto pattern, there are usually a list of basic blocks that are all targets of indirectbr instruction, and each basic block also has address taken and stored in a variable.
CHR pass could potentially clone these basic blocks, which would generate a cloned version of the indirectbr and clonved version of all basic blocks in the list.
However these basic blocks will not have their addresses taken and stored anywhere. So latter SimplifyCFG pass will simply remove all tehse cloned basic blocks, resulting in incorrect code.
To fix this, when searching for scopes, we skip scopes that contains BBs with addresses taken.
Added a few test cases.
Reviewed By: aeubanks, wenlei, hoy
Differential Revision: https://reviews.llvm.org/D103867
Also:
- add driver test (fsanitize-use-after-return.c)
- add basic IR test (asan-use-after-return.cpp)
- (NFC) cleaned up logic for generating table of __asan_stack_malloc
depending on flag.
for issue: https://github.com/google/sanitizers/issues/1394
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D104076
Adds the basic instrumentation needed for stack tagging.
Currently does not support stack short granules or TLS stack histories,
since a different code path is followed for the callback instrumentation
we use.
We may simply wait to support these two features until we switch to
a custom calling convention.
Patch By: xiangzhangllvm, morehouse
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D102901
This allows for using the frame record feature (which uses __hwasan_tls)
independently from however the user wants to access the shadow base, which
prior was only usable if shadow wasn't accessed through the TLS variable or ifuncs.
Frame recording can be explicitly set according to ShadowMapping::WithFrameRecord
in ShadowMapping::init. Currently, it is only enabled on Fuchsia and if TLS is
used, so this should mimic the old behavior.
Added an extra case to prologue.ll that covers this new case.
Differential Revision: https://reviews.llvm.org/D103841
