[libunwind,EHABI,ARM] Fix get/set of RA_AUTH_CODE.

According to EHABI32 §8.5.2, the PAC for the return address of a
function described in an exception table is supposed to be addressed
in the _Unwin

[libunwind,EHABI,ARM] Fix get/set of RA_AUTH_CODE.

According to EHABI32 §8.5.2, the PAC for the return address of a
function described in an exception table is supposed to be addressed
in the _Unwind_VRS_{Get,Set} API by setting regclass=_UVRSC_PSEUDO and
regno=0. (The space of 'regno' values is independent for each
regclass, and for _UVRSC_PSEUDO, there is only one valid regno so far.)

That is indeed what libunwind's _Unwind_VRS_{Get,Set} functions expect
to receive. But at two call sites, the wrong values are passed in:
regno is being set to UNW_ARM_RA_AUTH_CODE (0x8F) instead of 0, and in
one case, regclass is _UVRSC_CORE instead of _UVRSC_PSEUDO.

As a result, those calls to _Unwind_VRS_{Get,Set} return
_UVRSR_FAILED, which their callers ignore. So if you compile in the
AUTG instruction that actually validates the PAC, it will try to
validate what's effectively an uninitialised register as an
authentication code, and trigger a CPU fault even on correct exception
unwinding.

Reviewed By: danielkiss

Differential Revision: https://reviews.llvm.org/D128522

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[libunwind] Fix build warnings in Unwind-EHABI.cpp. NFC.

Differential Revision: https://reviews.llvm.org/D124371

[ARM][libunwind] add PACBTI-M support for libunwind

This patch implements the following:

- Emit PACBTI-M build attributes in libunwind asm files

- Authenticate LR in DWARF32 using PACBTI

Use Armv

[ARM][libunwind] add PACBTI-M support for libunwind

This patch implements the following:

- Emit PACBTI-M build attributes in libunwind asm files

- Authenticate LR in DWARF32 using PACBTI

Use Armv8.1-M.Main PACBTI extension to authenticate the return address
(stored in the LR register) before moving it to the PC (IP) register.

The AUTG instruction is used with the candidate return address, the CFA,
and the authentication code that is retrieved from the saved
pseudo-register RA_AUTH_CODE.

- Authenticate LR in EHABI using PACBTI

Authenticate the contents of the LR register using Armv8.1-M.Main PACBTI
extension.

A new frame unwinding instruction is introduced (0xb4). This
instruction pops out of the stack the return address authentication
code, which is then used in conjunction with the SP and the next-to-be
instruction pointer to perform authentication.

This authentication code is popped into a new register,
UNW_ARM_PSEUDO_PAC, which is a pseudo-register.

This patch is part of a series that adds support for the PACBTI-M extension of
the Armv8.1-M architecture, as detailed here:

https://community.arm.com/arm-community-blogs/b/architectures-and-processors-blog/posts/armv8-1-m-pointer-authentication-and-branch-target-identification-extension

The PACBTI-M specification can be found in the Armv8-M Architecture Reference
Manual:

https://developer.arm.com/documentation/ddi0553/latest

The following people contributed to this patch:

- Momchil Velikov
- Victor Campos
- Ties Stuij

Reviewed By: #libunwind, danielkiss, mstorsjo

Differential Revision: https://reviews.llvm.org/D112430

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[libunwind][ARM] Handle end of stack during unwind

When unwind step reaches the end of the stack that means the force unwind should notify the stop function.
This is not an error, it could mean just

[libunwind][ARM] Handle end of stack during unwind

When unwind step reaches the end of the stack that means the force unwind should notify the stop function.
This is not an error, it could mean just the thread is cleaned up completely.

Reviewed By: #libunwind, mstorsjo

Differential Revision: https://reviews.llvm.org/D109856

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[runtimes][NFC] Remove filenames at the top of the license notice

We've stopped doing it in libc++ for a while now because these names
would end up rotting as we move things around and copy/paste st

[runtimes][NFC] Remove filenames at the top of the license notice

We've stopped doing it in libc++ for a while now because these names
would end up rotting as we move things around and copy/paste stuff.
This cleans up all the existing files so as to stop the spreading
as people copy-paste headers around.

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[libunwind] Compile with -Wunused-but-set-variable

-Wunused-but-set-variable triggers a warning even the block of code is effectively dead.

Reviewed By: MaskRay

Differential Revision: https://revi

[libunwind] Compile with -Wunused-but-set-variable

-Wunused-but-set-variable triggers a warning even the block of code is effectively dead.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D107835

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[Arm][Unwind][libc++abi] Add _Unwind_ForcedUnwind to EHABI.

_Unwind_ForcedUnwind is not mandated by the EHABI but for compatibilty
reasons adding so the interface to higher layers would be the same.

[Arm][Unwind][libc++abi] Add _Unwind_ForcedUnwind to EHABI.

_Unwind_ForcedUnwind is not mandated by the EHABI but for compatibilty
reasons adding so the interface to higher layers would be the same.
Dropping EHABI specific _Unwind_Stop_Fn definition since it is not defined by EHABI.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D89570

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libunwind: add missing break statements in EHABI

Add missing break statements identified by static analysis tools.

Patch by Andrii Kurdiumov!

Reviewed By: compnerd, danielkiss

Differential Revisi

libunwind: add missing break statements in EHABI

Add missing break statements identified by static analysis tools.

Patch by Andrii Kurdiumov!

Reviewed By: compnerd, danielkiss

Differential Revision: https://reviews.llvm.org/D107537

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unwind: use a more portable endianness check in EHABI

The ARM specific code was trying to determine endianness using the
`__LITTLE_ENDIAN__` macro which is not guaranteed to be defined.
When not def

unwind: use a more portable endianness check in EHABI

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!

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unwind: rename `__personality_routine` to `_Unwind_Personality_Fn`

This patch renames `__personality_routine` to `_Unwind_Personality_Fn`
in `unwind.h`. Both `unwind.h` from clang and GCC headers us

unwind: rename `__personality_routine` to `_Unwind_Personality_Fn`

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!

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[libunwind][ARM] Fix types in _Unwind_VRS_Get.

This is a small fix for https://reviews.llvm.org/D64996. The types of
w0 and w1 in _Unwind_VRS_Get must be uint64_t, not uint32_t.

Committing as obvio

[libunwind][ARM] Fix types in _Unwind_VRS_Get.

This is a small fix for https://reviews.llvm.org/D64996. The types of
w0 and w1 in _Unwind_VRS_Get must be uint64_t, not uint32_t.

Committing as obvious.

llvm-svn: 366701

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[libunwind][ARM] Fix loading FP registers on big-endian targets

Summary:
The function Unwind-EHABI.cpp:_Unwind_VRS_Pop loads the saved values of
64-bit FP registers as two 32-bit words because they

[libunwind][ARM] Fix loading FP registers on big-endian targets

Summary:
The function Unwind-EHABI.cpp:_Unwind_VRS_Pop loads the saved values of
64-bit FP registers as two 32-bit words because they might not be
8-byte aligned. Combining these words into a 64-bit value has to be
done differently on big-endian platforms.

Reviewers: ostannard, john.brawn, dmgreen

Reviewed By: ostannard

Subscribers: kristof.beyls, christof, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D64996

llvm-svn: 366587

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[libunwind] Fix Unwind-EHABI.cpp:getByte on big-endian targets

Summary:
The function getByte is dependent on endianness and the current
behavior is incorrect on big-endian targets.

This patch fixes

[libunwind] Fix Unwind-EHABI.cpp:getByte on big-endian targets

Summary:
The function getByte is dependent on endianness and the current
behavior is incorrect on big-endian targets.

This patch fixes the issue.

Reviewers: phosek, ostannard, dmgreen, christof, chill

Reviewed By: ostannard, chill

Subscribers: chill, christof, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D64402

llvm-svn: 365505

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[libunwind] Export the unw_* symbols as weak symbols

libunwind defines the _Unwind_* ABI used by libc++abi. This ABI is a
stable quasi-standard common between multiple implementations such as
LLVM a

[libunwind] Export the unw_* symbols as weak symbols

libunwind defines the _Unwind_* ABI used by libc++abi. This ABI is a
stable quasi-standard common between multiple implementations such as
LLVM and GNU. The _U* symbol name space is also safely within the symbol
name space that standard C & C++ reserve for the implementation.

Futhermore, libunwind also defines several unw_* symbols, and references
these from the _Unwind_* entry points so the standard/reserved part of
the ABI is dependent on the unw_* part of the ABI. This is not OK for a
C or C++ implementation. The unw_* symbols are reserved for C and extern
"C" used by application code.

This change renames each unw_* function to __unw* and adds a weak alias
unw_* to keep the public <libunwind.h> ABI unchanged for backwards
compatibility. Every reference to unw_* in the implementation has been
changed to use __unw* so that if other unw_* definitions are in force
because nothing uses <libunwind.h> in a particular program, no _Unwind*
code path depends on any unw_* symbol. Furthemore, __unw_* symbols are
hidden, which saves PLT overhead in the shared library case.

In the future, we should cconsider untangling the unw_* API/ABI from the
_Unwind_* API/ABI. The internal API backing the _Unwind_* ABI
implementation should not rely on any nonstandard symbols not in the
implementation-reserved name space. This would then allow separating the
_Unwind_* API/ABI from unw_* entirely, but that's a more substantial
change that's going to require more significant refactoring.

Differential Revision: https://reviews.llvm.org/D59921

llvm-svn: 357640

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Drop the dependency on <algorithm>, add placement new inline

We haven't eliminated C++ library dependency altogether in D57251,
UnwindCursor.hpp had an unused dependency on <algorithm> which was
pul

Drop the dependency on <algorithm>, add placement new inline

We haven't eliminated C++ library dependency altogether in D57251,
UnwindCursor.hpp had an unused dependency on <algorithm> which was
pulling in other C++ headers. Removing that dependency also revealed
(correctly) that we need our own global placement new declaration. Now
libunwind should be independent of the C++ library.

Differential Revision: https://reviews.llvm.org/D57262

llvm-svn: 352553

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Update more file headers across all of the LLVM projects in the monorepo
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.

We understand that

Update more file headers across all of the LLVM projects in the monorepo
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

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Change unw_word_t to always have the same size as the pointer size

This matches the original libunwind API. This also unifies the
type between ARM EHABI and the other configurations, and allows
gett

Change unw_word_t to always have the same size as the pointer size

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

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[libunwind] Clean up macro usage.

Convention in libunwind is to use !defined(FOOT) not !FOO.

Differential Revision: https://reviews.llvm.org/D31078

llvm-svn: 299225

EHABI: mark some functions as exported

These are part of the EHABI specification and are exported to be available to
users. Mark them as `_LIBUNWIND_EXPORT` like the rest of the unwind interfaces.

EHABI: mark some functions as exported

These are part of the EHABI specification and are exported to be available to
users. Mark them as `_LIBUNWIND_EXPORT` like the rest of the unwind interfaces.

llvm-svn: 287283

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consistently add \n to log and trace messages

Previously most messages included a newline in the string, but a few of
them were missing. Fix these and simplify by just adding the newline in
the _LIB

consistently add \n to log and trace messages

Previously most messages included a newline in the string, but a few of
them were missing. Fix these and simplify by just adding the newline in
the _LIBUNWIND_LOG macro itself.

Differential Revision: https://reviews.llvm.org/D24026

llvm-svn: 280103

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libunwind: correct 'libuwind' typo

There were several instances of libuwind (missing an "n"), dating to
the initial import of libunwind.

llvm-svn: 280086

EHABI: fail on WMMX vops without WMMX support

When the unwinder is built without WMMX support, if we encounter a WMMX register
virtual operation, early rather than attempting to continue as we would

EHABI: fail on WMMX vops without WMMX support

When the unwinder is built without WMMX support, if we encounter a WMMX register
virtual operation, early rather than attempting to continue as we would not have
saved the register set anyways. This should never come down this path, but,
just in case, help it abort more explicitly.

llvm-svn: 279941

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EHABI: cover switch once more

When making WMMX support optional, we uncovered the switch. Add the missing
entries. Since the entry is a break leading to a dead path, it should get
optimized out ye

EHABI: cover switch once more

When making WMMX support optional, we uncovered the switch. Add the missing
entries. Since the entry is a break leading to a dead path, it should get
optimized out yet retain the switch overage.

llvm-svn: 279180

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libunwind: correct return code in unwinding trace log message

llvm-svn: 277215

[libunwind][ARM] Improve unwinder stack usage - Make WMMX support optional

These registers are only available on a limited set of ARM targets (those
based on XScale). Other targets should not have t

[libunwind][ARM] Improve unwinder stack usage - Make WMMX support optional

These registers are only available on a limited set of ARM targets (those
based on XScale). Other targets should not have to pay the cost of these.

This patch shaves off about ~300 bytes of stack usage and ~1KB of code-size.

Differential revision: http://reviews.llvm.org/D21991
Reviewers: bcraig, compnerd

Change-Id: I2d7a1911a193bd70b123e78747e1a7d1482463c7
llvm-svn: 274744

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