Currently, this function is present in the dynsym table of
libunwind.so (on ELF targets). Make the function static instead.
In the previous release (LLVM 10.x), this function was instead a lambda
function inside LocalAddressSpace::findUnwindSections, and because
LocalAddressSpace was marked with _LIBUNWIND_HIDDEN, the lambda
function was also a hidden symbol.
Differential Revision: https://reviews.llvm.org/D86372
When built in SEH mode, UnwindCursor contains a CONTEXT struct,
which is aligned to 16 bytes in most configurations, causing the
whole UnwindCursor object to have 16 byte alignment.
This fixes backtraces using _Unwind_Backtrace on x86_64 mingw,
where an unw_cursor_t allocated on the stack was misaligned before.
This is an ABI break for this struct for this configuration, but very
few callers call libunwind directly (and even fewer directly allocate
an unw_cursor_t anyway).
Differential Revision: https://reviews.llvm.org/D86102
Although it works fine with glibc, as currently implemented the
frameheader cache is incompatible with certain platforms with
slightly different locking semantics inside dl_iterate_phdr.
Therefore only enable it when it is turned on explicitly with
a configure-time option.
Differential Revision: https://reviews.llvm.org/D86163
Remove `_dyld_find_unwind_sections` implementation for macOS that is
10.6 or previous. 10.6 is no longer supported for TOT libunwind after
removing its libkeymgr dependency.
Reviewed By: mstorsjo, pete, #libunwind
Differential Revision: https://reviews.llvm.org/D86104
keymgr used to be used on MacOSX <= 10.6, however we don't build libunwind
from scratch for such old systems anymore. Hence, this code isn't useful
anymore.
Differential Revision: https://reviews.llvm.org/D84677
Previously, for large-enough values, getSLEB128 would attempt to shift
a signed int in the range [0..0x7f] by 28, 35, 42... bits, which is
undefined behavior and likely to fail.
Avoid shifting (-1ULL) by 70 for large values. e.g. For INT64_MAX, the
last two bytes will be:
- 0x7f [bit==56]
- 0x00 [bit==63]
Differential Revision: https://reviews.llvm.org/D83742
- For CIE version 1 (e.g. in DWARF 2.0.0), the return_address_register
field is a ubyte [0..255].
- For CIE version 3 (e.g. in DWARF 3), the field is instead a ULEB128
constant.
Previously, libunwind accepted a CIE version of 1 or 3, but always
parsed the field as ULEB128.
Clang always outputs CIE version 1 into .eh_frame. (It can output CIE
version 3 or 4, but only into .debug_frame.)
Differential Revision: https://reviews.llvm.org/D83741
Add missing `operator!=` and make `operator-` const for
`EHABISectionIterator`. This repairs the build of libunwind when
building with GCC.
Patch by Chad Duffin!
Reviewed By: compnerd, libunwind
Differential Revision: https://reviews.llvm.org/D81597
Summary:
This allows unwinding to work across signal handler frames where the IP of the previous frame is not the same as the current value of the RA register. This is particularly useful for acquiring backtraces from signal handlers.
I kept the size of the context structure the same to avoid ABI breakage; the PC is stored in the previously unused slot for register 0.
Reviewers: #libunwind, mhorne, lenary, luismarques, arichardson, compnerd
Reviewed By: #libunwind, mhorne, lenary, compnerd
Subscribers: kamleshbhalui, jrtc27, bsdjhb, arichardson, compnerd, simoncook, kito-cheng, shiva0217, rogfer01, rkruppe, psnobl, benna, Jim, s.egerton, sameer.abuasal, evandro, llvm-commits, libcxx-commits
Tags: #libunwind, #llvm
Differential Revision: https://reviews.llvm.org/D78931
The ARM specific code was trying to determine endianness using the
`__LITTLE_ENDIAN__` macro which is not guaranteed to be defined.
When not defined, it makes libunwind to build the big-endian code even
when the compiler builds for a little-endian target.
This change allows building libunwind with the `musl-gcc` toolchain
which does not define `__LITTLE_ENDIAN__`. Use `__BYTE_ORDER__`
instead.
Patch by Idan Freiberg!
Add a missing guard for `_LIBUNWIND_NO_HEAP` around code dealing with the
`.cfi_remember_state` and `.cfi_restore_state` instructions.
Patch by Amanieu d'Antras!
`__aarch64__` is defined for the target (since the beginning of arm64 support: clang 3.5).
`__arm64__` is only defined for the Darwin OS on AArch64.
`defined(__aarch64__) || defined(__arm64__)` can be simplied as `defined(__aarch64__)`
Darwin AArch64 uses %% as the assembly separator (see AArch64MCAsmInfo.cpp).
Make the intention explicit in src/assembly.h
With this change, the libunwind code base has no reference of `__arm64__`/`__arm64`.
Reviewed By: #libunwind, ldionne, mstorsjo
Differential Revision: https://reviews.llvm.org/D77829
When the EHHeaderInfo object filled by decodeEHHdr has fde_count == 0,
findFDE does the following:
- sets low = 0 and len = hdrInfo.fde_count as a preparation to start a
binary search
- because len is 0, the binary search loop is skipped
- the code still tries to find a table entry at
hdrInfo.table + low * tableEntrySize, and decode it.
This is wrong when fde_count is 0, and trying to decode a table entry
that isn't there will lead to reading garbage offsets and can cause
segfaults.
Differential Revision: https://reviews.llvm.org/D77679
Summary:
This patch follows libgcc's lead: When the return-address register is
zero, there won't be additional stack frames to examine, or gather
information about. Exit before spending time looking for something
known not to be found.
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77099
Summary:
This improves unwind performance quite substantially, and follows
a somewhat similar approach used in libgcc_s as described in the
thread here:
https://gcc.gnu.org/ml/gcc/2005-02/msg00625.html
On certain extremely exception heavy internal tests, the time
drops from about 80 minutes to about five minutes.
Subscribers: libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D75954
Summary:
Copying all of the saved register state on every entry to
parseInstruction is a severe performance contraint, especially
because most of this saved state is never used. On x86 linux
this is about 560 bytes, and will be more on other platforms.
When performance testing libunwind, this memcpy appears at the
top of nearly all our tests.
By only saving this state as needed, we see increasing in performance
of around 2.5% for the ctak test here.
https://github.com/clasp-developers/ctak
Certain internal extremely exception-heavy tasks run in about 2/3
the time.
Note that by stashing the new boolean inside what had been padding in
the original structure, this uses no additional memory.
Subscribers: fedor.sergeev, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D75692
We were seeing non-deterministic binary size differences depending on which
toolchain was used to build fuchsia. This is because libunwind embeded the
FILE path into a logging macro, even for release builds, which makes the code
dependent on the build directory.
This removes the file and line number from the error message. This is
consistent with how other runtimes report error, e.g.
https://github.com/llvm/llvm-project/blob/master/libcxxabi/src/abort_message.cpp#L30.
Differential Revision: https://reviews.llvm.org/D75890
Summary:
- Executable segment is usually segment 3. Look there for the address first.
- GNU_EH_FRAME_HEADER segment is usually near the end. Iterate from the end.
- Exit early if both phdrs have been found.
This is the last cl before a patch to cache the information this function
finds.
Subscribers: libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D75781
Summary:
This further cleans up the control flow and makes it easier to
optimize and replace portions in a subsequent patch.
This should be NFC, but given the amount of #ifdeffing here,
it may not be. So will watch the buildbots closely.
Also, as this is purely moving existing code around, I plan to
ignore the lint errors.
Reviewers: compnerd, miyuki, mstorsjo
Subscribers: libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D75705
Summary:
This cleans up control flow inside findUnwindSections, and will make
it easier to replace this code in a following patch. Also, expose the
data structure to allow use by a future replacment function.
Reviewers: mstorsjo, miyuki
Subscribers: krytarowski, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D75637
This reverts commit d93371238e.
The commit broke the build in several configurations (including
Windows and bare-metal). For details see comments in
https://reviews.llvm.org/D75480
Ryan Prichard
Martin Storsjö
Sterling Augustine
Steven Wu
Louis Dionne
Saleem Abdulrasool
Amanieu d'Antras
Brian Cain
Fangrui Song
Jorge Gorbe Moya
Mikael Holmen
Leonard Chan
Mikhail Maltsev