This change adds support for the dwarf PC register column in arm64, allowing
CFI directives to make use of it.
As of the last revision of the DWARF for ARM 64-bit architecture[0], the pc
register has been added as a valir register, with number 32.
This allows libunwinder to restore both pc and lr, which is useful
for stack switches and signal contexts.
[0]:
f52e1ad3f8/aadwarf64/aadwarf64.rst
Reviewed By: phosek, #libunwind
Differential Revision: https://reviews.llvm.org/D96901
Modify libunwind to support SjLj exception handling routines for VE.
In order to do that, we need to implement not only SjLj exception
handling routines but also a Registers_ve class. This implementation
of Registers_ve is incomplete. We will work on it later when we need
backtrace in libunwind.
Reviewed By: #libunwind, compnerd
Differential Revision: https://reviews.llvm.org/D94591
An AArch64 sigreturn trampoline frame can't currently be described
in a DWARF .eh_frame section, because the AArch64 DWARF spec currently
doesn't define a constant for the PC register. (PC and LR may need to
be restored to different values.)
Instead, use the same technique as libgcc or github.com/libunwind and
detect the sigreturn frame by looking for the sigreturn instructions:
mov x8, #0x8b
svc #0x0
If a sigreturn frame is detected, libunwind restores all the GPRs by
assuming that sp points at an rt_sigframe Linux kernel struct. This
behavior is a fallback mode that is only used if there is no ordinary
unwind info for sigreturn.
If libunwind can't find unwind info for a PC, it assumes that the PC is
readable, and would crash if it isn't. This could happen if:
- The PC points at a function compiled without unwind info, and which
is part of an execute-only mapping (e.g. using -Wl,--execute-only).
- The PC is invalid and happens to point to unreadable or unmapped
memory.
In the tests, ignore a failed dladdr call so that the tests can run on
user-mode qemu for AArch64, which uses a stack-allocated trampoline
instead of a vDSO.
Reviewed By: danielkiss, compnerd, #libunwind
Differential Revision: https://reviews.llvm.org/D90898
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
This patch renames `__personality_routine` to `_Unwind_Personality_Fn`
in `unwind.h`. Both `unwind.h` from clang and GCC headers use this name
instead of `__personality_routine`. With this patch one is also able to
build libc++abi with libunwind support on Windows.
Patch by Markus Böck!
Summary:
Add unwinding support for 64-bit RISC-V.
This is from the FreeBSD implementation with the following minor
changes:
- Renamed and renumbered DWARF registers to match the RISC-V ABI [1]
- Use the ABI mneumonics in getRegisterName() instead of the exact
register names
- Include checks for __riscv_xlen == 64 to facilitate adding the 32-bit
ABI in the future.
[1] https://github.com/riscv/riscv-elf-psabi-doc/blob/master/riscv-elf.md
Patch by Mitchell Horne (mhorne)
Reviewers: lenary, luismarques, compnerd, phosek
Reviewed By: lenary, luismarques
Subscribers: arichardson, sameer.abuasal, abidh, asb, aprantl, krytarowski, simoncook, kito-cheng, christof, shiva0217, rogfer01, rkruppe, PkmX, psnobl, benna, lenary, s.egerton, luismarques, emaste, cfe-commits
Differential Revision: https://reviews.llvm.org/D68362
This is unfinished, unused and incomplete. This could be brought back in
the future if there's a desire to build a more complete implementation,
but at the moment it's just bitrotting.
Differential Revision: https://reviews.llvm.org/D57252
llvm-svn: 352965
The existing typedef of unw_fpreg_t to uint64_t might work and be
correct for the ARM_EHABI case, but for dwarf, some cases in e.g.
DwarfInstructions.hpp convert between double and unw_fpreg_t.
When converting implicitly between double and unw_fpreg_t (uint64_t),
the values get interpreted as integers and converted to float and vice
versa, while the correct thing would be to keep the same bit pattern.
Avoid the whole issue by using the same definition of unw_fpreg_t
as all other architectures, when using dwarf unwinding on ARM.
Change assembler functions to take a void pointer instead of
unw_fpreg_t pointer, to avoid having a different mangled symbol name
depending on the actual value of this typedef.
Differential Revision: https://reviews.llvm.org/D57001
llvm-svn: 352461
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.
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: 351648
Summary:
Adds the register class implementation for Sparc.
Adds support for DW_CFA_GNU_window_save.
Adds save and restore context functionality.
Adds getArch() function to each Registers_ class to be able to separate
between DW_CFA_AARCH64_negate_ra_state and DW_CFA_GNU_window_save which
are both represented by the same constant.
On Sparc the return address is the address of the call instruction, so
an offset needs to be added when returning to skip the call instruction
and its delay slot. If the function returns a struct it is also necessary
to skip one extra instruction on Sparc V8.
Reviewers: jyknight, mclow.lists, mstorsjo, compnerd
Reviewed By: jyknight, compnerd
Subscribers: jgorbe, mgorny, christof, llvm-commits, fedor.sergeev, JDevlieghere, ldionne, libcxx-commits
Differential Revision: https://reviews.llvm.org/D55763
llvm-svn: 351044
Summary:
Adds the register class implementation for Sparc.
Adds support for DW_CFA_GNU_window_save.
Adds save and restore context functionality.
On Sparc the return address is the address of the call instruction,
so an offset needs to be added when returning to skip the call instruction
and its delay slot. If the function returns a struct it is also necessary
to skip one extra instruction.
Reviewers: jyknight, mclow.lists, mstorsjo, compnerd
Reviewed By: compnerd
Subscribers: fedor.sergeev, JDevlieghere, ldionne, libcxx-commits
Differential Revision: https://reviews.llvm.org/D55763
llvm-svn: 350705
This doesn't yet implement inspecting the .pdata/.xdata to find the
LSDA pointer (in UnwindCursor::getInfoFromSEH), but normal C++
exception handling seems to run just fine without it. (The only
place I can see where it's even referenced is in
unwind_phase2_forced, and I can't find a codepath where libcxxabi
would end up calling that.)
Differential Revision: https://reviews.llvm.org/D55674
llvm-svn: 349532
- Follow up to revision r342895
- gcc would not build libunwind with the earlier patch as the autia1716
instruction wasn't allowed to be assembled for pre armv8.3a targets
- The autia1716 instruction lives in the hint space encodings so is a valid
instruction for all armv8a targets
- To work around this I have swapped out the autia1716 instruction for the hint
instruction
Differential Revision: https://reviews.llvm.org/D55700
llvm-svn: 349140
- When return address signing is enabled, the LR may be signed on function entry
- When an exception is thrown the return address is inspected used to unwind the call stack
- Before this happens, the return address must be correctly authenticated to avoid causing an abort by dereferencing the signed pointer
Differential Revision: https://reviews.llvm.org/D51432
llvm-svn: 342895
Even though SEH for ARM is incomplete, make what code already exists
at least compile correctly.
The _LIBUNWIND_CURSOR_SIZE wasn't correct.
ARM (and AArch64) have a DISPATCHER_CONTEXT field named TargetPc
instead of TargetIp.
For the libunwind.h UNW_* constants, there is no UNW_ARM_PC, only
UNW_ARM_IP.
Don't use 'r' as loop variable when 'r' already is a Registers_arm
member.
Differential Revision: https://reviews.llvm.org/D51530
llvm-svn: 341217
Summary:
I've tested this implementation on x86-64 to ensure that it works. All
`libc++abi` tests pass, as do all `libc++` exception-related tests. ARM
still remains to be implemented (@compnerd?).
Special thanks to KJK::Hyperion for his excellent series of articles on
how EH works on x86-64 Windows. (Seriously, check it out. It's awesome.)
I'm actually not sure if this should go in as is. I particularly don't
like that I duplicated the UnwindCursor class for this special case.
Reviewers: mstorsjo, rnk, compnerd, smeenai, javed.absar
Subscribers: mgorny, kristof.beyls, christof, chrib, cfe-commits, compnerd, llvm-commits
Differential Revision: https://reviews.llvm.org/D50564
llvm-svn: 341125
Summary:
Make the `_Unwind_Exception` struct correct under SEH. Add a
declaration of `_GCC_specific_handler()`, which is used by SEH versions
of Itanium personality handlers to do common setup. Roughly corresponds
to Clang's D50380.
Reviewers: mstorsjo, rnk, compnerd, smeenai
Subscribers: christof, chrib, cfe-commits, llvm-commits
Differential Revision: https://reviews.llvm.org/D50414
llvm-svn: 339258
This makes it possible to unwind hardware exception stack frames,
which necessarily save every register and so need an extra column
for storing the return address. CFI for the exception handler could
then look as follows:
.globl exception_vector
exception_vector:
.cfi_startproc
.cfi_signal_frame
.cfi_return_column 32
l.addi r1, r1, -0x100
.cfi_def_cfa_offset 0x100
l.sw 0x00(r1), r2
.cfi_offset 2, 0x00-0x100
l.sw 0x04(r1), r3
.cfi_offset 3, 0x04-0x100
l.sw 0x08(r1), r4
.cfi_offset 4, 0x08-0x100
l.mfspr r3, r0, SPR_EPCR_BASE
l.sw 0x78(r1), r3
.cfi_offset 32, 0x78-0x100
l.jal exception_handler
l.nop
l.lwz r2, 0x00(r1)
l.lwz r3, 0x04(r1)
l.lwz r4, 0x08(r1)
l.jr r9
l.nop
.cfi_endproc
This register could, of course, also be accessed by the trace
callback or personality function, if so desired.
llvm-svn: 332513
Summary:
For MIPS ABIs with 64-bit floating point registers including newabi
and O32 with 64-bit floating point registers, just save and restore the
32 floating-point registers as doubles.
For O32 MIPS with 32-bit floating-point registers, save and restore the
individual floating-point registers as "plain" registers. These registers
are encoded as floats rather than doubles, but the DWARF unwinder
assumes that floating-point registers are stored as doubles when reading
them from memory (via AddressSpace::getDouble()). Treating the
registers as "normal" registers instead causes the DWARF unwinder to
fetch them from memory as a 32-bit register. This does mean that for
O32 with 32-bit floating-point registers unw_get_fpreg() and
unw_set_fpreg() do not work. One would have to use unw_get_reg()
and unw_set_reg() instead. However, DWARF unwinding works
correctly as the DWARF CFI emits records for individual 32-bit
floating-point registers even when they are treated as doubles stored
in paired registers. If the lack of unw_get/set_fpreg() becomes a pressing
need in the future for O32 MIPS we could add in special handling to
make it work.
Reviewers: sdardis, compnerd
Reviewed By: sdardis
Differential Revision: https://reviews.llvm.org/D41968
llvm-svn: 332414
Summary:
N32 uses the same register context as N64. However, N32 requires one
change to properly fetch addresses from registers stored in memory.
Since N32 is an ILP32 platform, getP() only fetches the first 32-bits
of a stored register. For a big-endian platform this fetches the
upper 32-bits which will be zero. To fix this, add a new
getRegister() method to AddressSpace which is responsible for
extracting the address stored in a register in memory. This matches
getP() for all current ABIs except for N32 where it reads the 64-bit
register and returns the low 32-bits as an address. The
DwarfInstructions::getSavedRegister() method uses
AddressSpace::getRegister() instead of AddressSpace::getP().
Reviewers: sdardis, compnerd
Reviewed By: sdardis
Differential Revision: https://reviews.llvm.org/D39074
llvm-svn: 326250
The Registers_ppc64 class needed a couple of changes, both to accommodate the
new registers as well as to handle the overlaps of VS register set
without wasting space.
The save/restore code of V and VS registers was added.
As VS registers depend on the VMX extension, they are processed only if
VMX support is detected (_ARCH_PWR8 for now).
Patch by Leandro Lupori!
Differential Revision: https://reviews.llvm.org/D41906
llvm-svn: 322596
This is in preparation for adding support for N32 unwinding which reuses
the newabi register class.
Reviewed By: compnerd
Differential Revision: https://reviews.llvm.org/D41842
llvm-svn: 322093
Initial working version of libunwind for PowerPC 64. Tested on
little-endian ppc64 host only.
Based on the existing PowerPC 32 code.
It supports:
- context save/restore (unw_getcontext, unw_init_local, unw_resume)
- read/write from/to saved registers
- backtrace (unw_step)
Patch by Leandro Lupori!
Differential Revision: https://reviews.llvm.org/D41386
Now builds with LIBUNWIND_ENABLE_CROSS_UNWINDING=ON should
work.
llvm-svn: 321680
Initial working version of libunwind for PowerPC 64. Tested on
little-endian ppc64 host only.
Based on the existing PowerPC 32 code.
It supports:
- context save/restore (unw_getcontext, unw_init_local, unw_resume)
- read/write from/to saved registers
- backtrace (unw_step)
Patch by Leandro Lupori!
Differential Revision: https://reviews.llvm.org/D41386
llvm-svn: 321667
This supports the soft-float ABI only and has been tested with both clang
and gcc on FreeBSD.
Reviewed By: sdardis, compnerd
Differential Revision: https://reviews.llvm.org/D38110
llvm-svn: 320528
The previous definition of _LIBUNWIND_HIGHEST_DWARF_REGISTER seems
to be a copy of the ARM64 value (introduced in SVN r276128); since
the code actually hasn't compiled properly for arm in dwarf mode
before, this hasn't actually been used. Set it to the correct value
based on the UNW_ARM_* enum values.
The iwmmx control variables have to be made mutable, since they are
touched from within getRegister (which previously wasn't const), and
getRegister is used on a const Registers object in DwarfInstructions.hpp.
Differential Revision: https://reviews.llvm.org/D39251
llvm-svn: 317192
This matches the original libunwind API. This also unifies the
type between ARM EHABI and the other configurations, and allows
getting rid of a number of casts in log messages.
The cursor size updates for ppc and or1k are untested, but
unw_proc_info_t shrinks by 4 uint64_t units on i386 at least.
Differential Revision: https://reviews.llvm.org/D39365
llvm-svn: 316942
This restores the previous behaviour of the Registers_* classes
after SVN r316745.
Differential Revision: https://reviews.llvm.org/D39382
llvm-svn: 316843
Clang doesn't currently support building for windows/x86_64 with
dwarf by setting command line parameters, but if manually modified
to use dwarf, we can make libunwind work in this configuration
as well.
Also include i386 in the docs when adding this as a supported
configuration; libunwind already works for i386 windows, but
can fail due to an issue unrelated to windows itself.
Differential Revision: https://reviews.llvm.org/D38819
llvm-svn: 316747
This avoids having to keep the same information duplicated in multiple
places.
Adjust _LIBUNWIND_HIGHEST_DWARF_REGISTER to actually have the value
of the highest used register and only use the value
_LIBUNWIND_HIGHEST_DWARF_REGISTER + 1 (kMaxRegisterNumber + 1) for
allocating the savedRegisters array.
Differential Revision: https://reviews.llvm.org/D39281
llvm-svn: 316745
This was missed in SVN r274744 when the WMMX part was made optional;
when made optional, some struct fields were reordered, which caused
the total struct size to grow due to padding/alignment.
llvm-svn: 316559
It seems that GCC interprets `__attribute__((__aligned__))` as 8-byte
alignment on ARM, but clang does not. Explicitly specify the
double-word alignment value to ensure that the structure is properly
aligned.
llvm-svn: 311574
The C++ ABI requires that the exception object is double-word aligned.
The alignment attribute was applied to the `_Unwind_Exception` type
which is used on non-EHABI targets. On EHABI, the exception object type
is `_Unwind_Control_Block`. Apply the explicit maximal alignment on the
type to ensure that the allocation has the correct alignment.
Resolves PR33858!
llvm-svn: 311562
Restore the `libunwind.h` enumeration values back to the inverted
values. This diverges from the DWARF definition of the register values.
However, this allows our header to be compatible with other unwind
implementations (e.g. HP, GNU Savannah, GCC).
The register IDs are only swapped in the header and need to be unswapped
when accessing the unwind register file. The flipped EBP and ESP only
applies on non-Apple x86 targets.
When optimizations were enabled, EBP and ESP would no longer be
equivalent. As a result, the incorrect access on Linux would manifest
as a failure to unwind the stack. We can now unwind the stack with and
without FPO on Linux x86.
Resolves PR30879!
llvm-svn: 292723
Summary:
During building of recent compiler-rt sources on FreeBSD for arm, I
noticed that our unwind.h (which originates in libunwind) was missing
the `_US_ACTION_MASK` constant:
compiler-rt/lib/builtins/gcc_personality_v0.c:187:18: error: use of undeclared identifier '_US_ACTION_MASK'
if ((state & _US_ACTION_MASK) != _US_UNWIND_FRAME_STARTING)
^
It appears that both clang's internal unwind.h, and libgcc's unwind.h
define this constant as 3, so let's add this to libunwind's version too.
Reviewers: logan, kledzik, davide, emaste
Subscribers: joerg, davide, aemerson, emaste, llvm-commits
Differential Revision: https://reviews.llvm.org/D24222
llvm-svn: 280669
For historical reasons i386 has ebp and esp swapped in the eh_frame
register numbering on at least Darwin. That is:
Darwin FreeBSD
Reg # eh_frame eh_frame DWARF
===== ======== ======== =====
4 ebp esp esp
5 esp ebp ebp
Although the UNW_X86_* constants are not intended to be coupled with
DWARF / eh_frame numbering they are currently conflated in libunwind.
Differential Revision: https://reviews.llvm.org/D22508
llvm-svn: 280099
Summary: _Unwind_Exception is required to be double word aligned. Currently the struct is under aligned.
Reviewers: mclow.lists, compnerd, kledzik, emaste
Subscribers: emaste, cfe-commits
Differential Revision: https://reviews.llvm.org/D22543
llvm-svn: 276215
Kamlesh Kumar