| Age | Commit message (Collapse) | Author |
|---|
|
Specially when dealing with different address spaces, CFAs could start
from addresses like 0. For instance, Nvidia GPUs have instructions to
read from local memory that use 0-based offsets and stack memory can be
referenced by these offsets rather than global addresses. Note that ABIs
could already specify what they consider to be valid CFA values but this
was never used in these parts of the unwinder code. For most ABIs, this
makes the validation more strict, as they already used to discard 0s and
then checked for alignment which would discard 1s. There a few
exceptions where 0s were possible and this makes it less strict, like
the RISCV and ARC ABIs.
@jasonmolenda Would you be the appropriate reviewer for this?
Also cc. @clayborg @walter-erquinigo
|
|
Based on testing on processors that use pointer metadata, and with all
the work done to delay calls to FixDataAddress, this is no longer
necessary.
Note that, with debugserver in particular, this is an NFC change: the
code path here is for frame zero, and debugserver will strip metadata
when reading fp from frame zero anyway.
|
|
The first call, in InitializeNonZerothFrame, is inside a logging branch.
For that, it's better to log the real value instead of the fixed one.
The second call, inside RegisterContextUnwind::ReadFrameAddress, is
computing an address which is then passed to
ReadRegisterValueFromMemory, which boils down to a Process::ReadMemory,
which fixes the address if it wants to. The current variable names are
misleading, making readers believe it is the cfa value itself that is
being passed to Fix*Address; that's not the case. This commit renames
the variable to make this abundantly clear.
|
|
[lldb] Track CFA pointer metadata in StackID
In this commit:
9c8e71644227 [lldb] Make StackID call Fix{Code,Data} pointers (#152796)
We made StackID keep track of the CFA without any pointer metadata in
it. This is necessary when comparing two StackIDs to determine which one
is "younger".
However, the CFA inside StackIDs is also used in other contexts through
the method StackID::GetCallFrameAddress. One notable case is
DWARFExpression: the computation of `DW_OP_call_frame_address` is done
using StackID. This feeds into many other places, e.g. expression
evaluation may require the address of a variable that is computed from
the CFA; to access the variable without faulting, we may need to
preserve the pointer metadata. As such, StackID must be able to provide
both versions of the CFA.
In the spirit of allowing consumers of pointers to decide what to do
with pointer metadata, this patch changes StackID to store both versions
of the cfa pointer. Two getter methods are provided, and all call sites
except DWARFExpression preserve their existing behavior (stripped
pointer). Other alternatives were considered:
* Just store the raw pointer. This would require changing the
comparisong operator `<` to also receive a Process, as the comparison
requires stripped pointers. It wasn't clear if all call-sites had a
non-null process, whereas we know we have a process when creating a
StackID.
* Store a weak pointer to the process inside the class, and then strip
metadata as needed. This would require a `weak_ptr::lock` in many
operations of LLDB, and it felt wasteful. It also prevents stripping
of the pointer if the process has gone away.
This patch also changes RegisterContextUnwind::ReadFrameAddress, which
is the method computing the CFA fed into StackID, to also preserve the
signature pointers.
|
|
When a processor faults/is interrupted/gets an exception, it will stop
running code and jump to an exception catcher routine. Most processors
will store the pc that was executing in a system register, and the
catcher functions have special instructions to retrieve that & possibly
other registers. It may then save those values to stack, and the author
can add .cfi directives to tell lldb's unwinder where to find those
saved values.
ARM Cortex-M (microcontroller) processors have a simpler mechanism where
a fixed set of registers are saved to the stack on an exception, and a
unique value is put in the link register to indicate to the caller that
this has taken place. No special handling needs to be written into the
exception catcher, unless it wants to inspect these preserved values.
And it is possible for a general stack walker to walk the stack with no
special knowledge about what the catch function does.
This patch adds an Architecture plugin method to allow an Architecture
to override/augment the UnwindPlan that lldb would use for a stack
frame, given the contents of the return address register. It resembles a
feature where the LanguageRuntime can replace/augment the unwind plan
for a function, but it is doing it at offset by one level. The
LanguageRuntime is looking at the local register context and/or symbol
name to decide if it will override the unwind rules. For the Cortex-M
exception unwinds, we need to modify THIS frame's unwind plan if the
CALLER's LR had a specific value. RegisterContextUnwind has to retrieve
the caller's LR value before it has completely decided on the UnwindPlan
it will use for THIS stack frame.
This does mean that we will need one additional read of stack memory
than we currently do when unwinding, on Armv7 Cortex-M targets. The
unwinder walks the stack lazily, as stack frames are requested, and so
now if you ask for 2 stack frames, we will read enough stack to walk 2
frames, plus we will read one extra word of memory, the spilled LR value
from the stack. In practice, with 512-byte memory cache reads, this is
unlikely to be a real performance hit.
This PR includes a test with a yaml corefile description and a JSON
ObjectFile, incorporating all of the necessary stack memory and symbol
names from a real debug session I worked on. The architectural default
unwind plans are used for all stack frames except the 0th because
there's no instructions for the functions, and no unwind info. I may
need to add an encoding of unwind fules to ObjectFileJSON in the future
as we create more test cases like this.
This PR depends on the yaml2macho-core utility from
https://github.com/llvm/llvm-project/pull/153911 to run its API test.
rdar://110663219
|
|
`cfa_reg_contents` is a local variable. Whatever value we assign there
right before the `return` statement will be lost anyway.
Co-authored-by: Matej Košík <matej.kosik@codasip.com>
|
|
The test for this is artificial as I'm not aware of any upstream targets
that use DW_CFA_val_offset
RegisterContextUnwind::ReadFrameAddress now reports how it's attempting
to obtain the CFA unless all success/failure cases emit logs that
clearly identify the method it was attempting. Previously several of the
existing failure paths emit no message or a message that's
indistinguishable from those on other paths.
|
|
RegisterContextUnwind::SavedLocationForRegister is around 450 lines that
first find an abstract register location (e.g. "CFA-8") for a register
by looking in the UnwindPlans. Then it evaluates the abstract register
location to create a concrete register location (e.g. "stored at address
0x...", "live in register at frame 0"). There are some complicated cases
in the first half of the method to handle return address register
architectures correctly, in particular.
Looking at the two halves, they're both exactly 226 lines long and
there's little involvement between them except for passing an abstract
register location along.
(there were some parts in the "abstract register location" code that
would set the concrete register location, unnecessarily)
It's also a complex enough method that there are some bits of code that
aren't actually doing anything at this point.
This patch adds a RegisterContextUnwind::GetAbstractRegisterLocation
method, which does the first half, and has a clearly defined return
values.
The code to convert an AbstractRegisterLocation into a
ConcreteRegisterLocation remains in SavedLocationForRegister.
It's a bit of a tricky patch to visually inspect, despite it not
changing functionality, the reorganizations and rewrites make the diff
unreadable. Nearly all the real changes are in the "find the abstract
register location" first half of the method. I think reading the new
code in its new form is the easiest way to inspect this PR. With a
defined interface between the two of what is expected, it's pretty easy
to look at the code and reason about whether it is written correctly.
(whereas before, that was very difficult, for me at least.)
---------
Co-authored-by: Pavel Labath <pavel@labath.sk>
|
|
Basically, disable everything except the eh_frame unwind plan, as that's
the only one which supports this right now. The other plans are working
with now trying the interpret everything in between the function parts
as a part of the function, which is more likely to produce wrong results
than correct ones.
I changed the interface for object file plans, to give the
implementations a chance to implement this correctly, but I haven't
actually converted PECallFrameInfo (its only implementation) to handle
that. (from the looks of things, it should be relatively easy to do, if
it becomes necessary)
I'm also deleting UnwindPlan::GetFirstNonPrologueInsn, as it's not used,
and it doesn't work for discontinuous functions.
|
|
|
|
AddressFunctionScope was always returning the first address range of the
function (assuming it was the only one). This doesn't work for
RegisterContextUnwind (it's only caller), when the function doesn't
start at the lowest address because it throws off the 'how many bytes
"into" a function I am' computation. This patch replaces the result with
a call to (recently introduced)
SymbolContext::GetFunctionOrSymbolAddress.
|
|
Re-landing this patch with small tweaks to address CI bot failures
as it was run on many different configurations. I think the test
may run on aarch64 Linux systems now.
When a frameless function faults or is interrupted asynchronously, the
UnwindPlan MAY have no register location rule for the return address
register (lr on arm64); the value is simply live in the lr register when
it was interrupted, and the frame below this on the stack -- e.g.
sigtramp on a Unix system -- has the full register context, including
that register.
RegisterContextUnwind::SavedLocationForRegister, when asked to find the
caller's pc value, will first see if there is a pc register location. If
there isn't, on a Return Address Register architecture like
arm/mips/riscv, we rewrite the register request from "pc" to "RA
register", and search for a location.
On frame 0 (the live frame) and an interrupted frame, the UnwindPlan may
have no register location rule for the RA Reg, that is valid. A
frameless function that never calls another may simply keep the return
address in the live register the whole way. Our instruction emulation
unwind plans explicitly add a rule (see Pavel's May 2024 change
https://github.com/llvm/llvm-project/pull/91321 ), but an UnwindPlan
sourced from debug_frame may not.
I've got a case where this exactly happens - clang debug_frame for arm64
where there is no register location for the lr in a frameless function.
There is a fault in the middle of this frameless function and we only
get the lr value from the fault handler below this frame if lr has a
register location of `IsSame`, in line with Pavel's 2024 change.
Similar to how we see a request of the RA Reg from frame 0 after failing
to find an unwind location for the pc register, the same style of
special casing is needed when this is a function that was interrupted.
Without this change, we can find the pc of the frame that was executing
when it was interrupted, but we need $lr to find its caller, and we
don't descend down to the trap handler to get that value, truncating the
stack.
rdar://145614545
|
|
|
|
This test is failing on the LLDB Incremental bot (arm64), which is
running an older set of tools (Xcode 15.2) and OS (macOS 14.1) and
the CFI directives must not be emitted correctly by either the tools
or the OS. I will need to reproduce how this is compiling on that
older setup and see what the issue is. Reverting for now so the
bots are not blocked.
This reverts commit e897cb139ee6ef5c145fed5394c4d96baa658e6b.
|
|
When a frameless function faults or is interrupted asynchronously, the
UnwindPlan MAY have no register location rule for the return address
register (lr on arm64); the value is simply live in the lr register when
it was interrupted, and the frame below this on the stack -- e.g.
sigtramp on a Unix system -- has the full register context, including
that register.
RegisterContextUnwind::SavedLocationForRegister, when asked to find the
caller's pc value, will first see if there is a pc register location. If
there isn't, on a Return Address Register architecture like
arm/mips/riscv, we rewrite the register request from "pc" to "RA
register", and search for a location.
On frame 0 (the live frame) and an interrupted frame, the UnwindPlan may
have no register location rule for the RA Reg, that is valid. A
frameless function that never calls another may simply keep the return
address in the live register the whole way. Our instruction emulation
unwind plans explicitly add a rule (see Pavel's May 2024 change
https://github.com/llvm/llvm-project/pull/91321 ), but an UnwindPlan
sourced from debug_frame may not.
I've got a case where this exactly happens - clang debug_frame for arm64
where there is no register location for the lr in a frameless function.
There is a fault in the middle of this frameless function and we only
get the lr value from the fault handler below this frame if lr has a
register location of `IsSame`, in line with Pavel's 2024 change.
Similar to how we see a request of the RA Reg from frame 0 after failing
to find an unwind location for the pc register, the same style of
special casing is needed when this is a function that was interrupted.
Without this change, we can find the pc of the frame that was executing
when it was interrupted, but we need $lr to find its caller, and we
don't descend down to the trap handler to get that value, truncating the
stack.
rdar://145614545
|
|
This patch uses the previously build infrastructure to parse multiple
FDE entries into a single unwind plan. There is one catch though: we
parse only one FDE entry per unwind range. This is not fully correct
because lldb coalesces adjecant address ranges, which means that
something that originally looked like two separate address ranges (and
two FDE entries) may get merged into one because if the linker decides
to put the two ranges next to each other. In this case, we will ignore
the second FDE entry.
It would be more correct to try to parse another entry when the one we
found turns out to be short, but I'm not doing this (yet), because:
- this is how we've done things so far (although, monolithic functions
are unlikely to have more than one FDE entry)
- in cases where we don't have debug info or (full) symbol tables, we
can end up with "symbols" which appear to span many megabytes
(potentially, the whole module). If we tried to fill short FDE entries,
we could end up parsing the entire eh_frame section in a single go. In a
way, this would be more correct, but it would also probably be very
slow.
I haven't quite decided what to do about this case yet, though it's not
particularly likely to happen in the "production" cases as typically the
functions are split into two parts (hot/cold) instead of one part per
basic block.
|
|
(#134246)
This reverts commit 094904303d50e0ab14bc5f2586a602f79af95953, reapplying
d7afafdbc464e65c56a0a1d77bad426aa7538306 (#133247).
The failure ought to be fixed by
0509932bb6a291ba11253f30c465ab3ad164ae08.
|
|
It's value is not set on all control flow paths. I believe this should
fix the failure on some buildbots after #133247.
|
|
This reverts commit d7afafdbc464e65c56a0a1d77bad426aa7538306.
Caused remote Linux to Linux buildbot failure
https://lab.llvm.org/buildbot/#/builders/195/builds/7046.
|
|
These plans are cached and accessed from multiple threads. Modifying
them would be a Bad Idea(tm).
|
|
(#133250)
The function had special handling for -1, but that is incompatible with
functions whose entry point is not the first address. Use std::nullopt
instead.
|
|
Replace the by-ref return value with an actual result.
|
|
The whole unwind plan is already stored in a shared pointer, and there's
no need to persist Rows individually. If there's ever a need to do that,
there are at least two options:
- copy the row (they're not that big, and they're being copied left and
right during construction already)
- use the shared_ptr subobject constructor to create a shared_ptr which
points to a Row but holds the entire unwind plan alive
This also changes all of the getter functions to return const Row
pointers, which is important for safety because all of these objects are
cached and potentially accessed from multiple threads. (Technically one
could hand out `shared_ptr<const Row>`s, but we don't have a habit of
doing that.)
As a next step, I'd like to remove the internal UnwindPlan usages of the
shared pointer, but I'm doing this separately to gauge feedback, and
also because the patch got rather big.
|
|
This reverts commit fd424179dcb3417fc0675f77d2bf06c750dd1c33.
This patch has two problems. First, it is unnecessary, Pavel landed
a fix a week or so before mine which solves this problem in
bbd54e08b08f5ccd38c4665178e65c58f7b14459 . Second, the fix is
incorrect; for a function above a trap handler, where all registers
are available, this patch would have lldb fetch the return address
register from frame 0. This might be 10 frames up in the stack;
the frame 0 return address register is incorrect. The change would
have been correct a short bit later than this, but Pavel's fix is
executed earlier in the function and none of this is needed.
|
|
This is similar to 9fe455fd0c7d, but for FA locations instead of
register locations.
This is useful for unwind plans that cannot create abstract unwind
rules, but instead must inspect the state of the program to determine
the current CFA.
|
|
lldb has two RegisterLocation classes that do slightly different things.
UnwindPlan::Row::RegisterLocation (new: AbstractRegisterLocation) has a
description of how to find a register's value or location, not specific
to a particular stopping point. It may say that at a given offset into a
function, the caller's register has been spilled to stack memory at CFA
minus an offset. Or it may say that the caller's register is at a DWARF
exprssion.
UnwindLLDB::RegisterLocation (new: ConcreteRegisterLocation) is a
specific address where the register is currently stored, or the register
it has been copied into, or its value at this point in the current
function execution.
When lldb stops in a function, it interprets the
AbstractRegisterLocation's instructions using the register context and
stack memory, to create the ConcreteRegisterLocation at this point in
time for this stack frame.
I'm not thrilled with AbstractRegisterLocation and
ConcreteRegisterLocation, but it's better than the same name and it will
be easier to update them if someone suggests a better pair.
|
|
This is useful for language runtimes that compute register values by
inspecting the state of the currently running process. Currently, there
are no mechanisms enabling these runtimes to set register values to
arbitrary values.
The alternative considered would involve creating a dwarf expression
that produces an arbitrary integer (e.g. using OP_constu). However, the
current data structure for Rows is such that they do not own any memory
associated with dwarf expressions, which implies any such expression
would need to have static storage and therefore could not contain a
runtime value.
Adding a new rule for constants leads to a simpler implementation. It's
also worth noting that this does not make the "Location" union any
bigger, since it already contains a pointer+size pair.
|
|
In RegisterContextUnwind::SavedLocationForRegister we have special logic
for retrieving the Return Address register when it has the caller's
return address in it. An example would be the lr register on AArch64.
This register is never retrieved from a newer stack frame because it is
necessarly overwritten by a normal ABI function call. We allow frame 0
to provide its lr value to get the caller's return address, if it has
not been overwritten/saved to stack yet.
When a function is interrupted asynchronously by a POSIX signal
(sigtramp), or a fault handler more generally, the sigtramp/fault
handler has the entire register context available. In this situation, if
the fault handler is frame 0, the function that was async interrupted is
frame 1 and frame 2's return address may still be stored in lr. We need
to get the lr value for frame 1 from the fault handler in frame 0, to
get the return address for frame 2.
Without this fix, a frameless function that faults in a firmware
environment (that's where we've seen this issue most commonly) hasn't
spilled lr to stack, so we need to retrieve it from the fault handler's
full-register-context to find the caller of the frameless function that
faulted.
It's an unsurprising fix, all of the work was finding exactly where in
RegisterContextUnwind we were only allowing RA register use for frame 0,
when it should have been frame 0 or above a fault handler function.
rdar://127518945
|
|
Change the signature of `DWARFExpression::Evaluate` and
`DWARFExpressionList::Evaluate` to return an `llvm::Expected` instead of a
boolean. This eliminates the `Status` output parameter and generally improves
error handling.
|
|
(#92503)
…unction (#91321)"
This reapplies fd1bd53ba5a06f344698a55578f6a5d79c457e30, which was
reverted due to a test failure on aarch64/windows. The failure was
caused by a combination of several factors:
- clang targeting aarch64-windows (unlike msvc, and unlike clang
targeting other aarch64 platforms) defaults to -fomit-frame-pointers
- lldb's code for looking up register values for `<same>` unwind rules
is recursive
- the test binary creates a very long chain of fp-less function frames
(it manages to fit about 22k frames before it blows its stack)
Together, these things have caused lldb to recreate the same deep
recursion when unwinding through this, and blow its own stack as well.
Since lldb frames are larger, about 4k frames like this was sufficient
to trigger the stack overflow.
This version of the patch works around this problem by increasing the
frame size of the test binary, thereby causing it to blow its stack
sooner. This doesn't fix the issue -- the same problem can occur with a
real binary -- but it's not very likely, as it requires an infinite
recursion in a simple (so it doesn't use the frame pointer) function
with a very small frame (so you can fit a lot of them on the stack).
A more principled fix would be to make lldb's lookup code non-recursive,
but I believe that's out of scope for this patch.
The original patch description follows:
A leaf function may not store the link register to stack, but we it can
still end up being a non-zero frame if it gets interrupted by a signal.
Currently, we were unable to unwind past this function because we could
not read the link register value.
To make this work, this patch:
- changes the function-entry unwind plan to include the `fp|lr = <same>`
rules. This in turn necessitated an adjustment in the generic
instruction emulation logic to ensure that `lr=[sp-X]` can override the
`<same>` rule.
- allows the `<same>` rule for pc and lr in all
`m_all_registers_available` frames (and not just frame zero).
The test verifies that we can unwind in a situation like this, and that
the backtrace matches the one we computed before getting a signal.
|
|
(#91321)"
This reverts commit fd1bd53ba5a06f344698a55578f6a5d79c457e30.
TestInterruptBacktrace was broken on AArch64/Windows as a result of this change.
See lldb-aarch64-windows buildbot here:
https://lab.llvm.org/buildbot/#/builders/219/builds/11261
|
|
A leaf function may not store the link register to stack, but we it can
still end up being a non-zero frame if it gets interrupted by a signal.
Currently, we were unable to unwind past this function because we could
not read the link register value.
To make this work, this patch:
- changes the function-entry unwind plan to include the `fp|lr = <same>`
rules. This in turn necessitated an adjustment in the generic
instruction emulation logic to ensure that `lr=[sp-X]` can override the
`<same>` rule.
- allows the `<same>` rule for pc and lr in all
`m_all_registers_available` frames (and not just frame zero).
The test verifies that we can unwind in a situation like this, and that
the backtrace matches the one we computed before getting a signal.
|
|
Those fixes were taken from https://reviews.llvm.org/D137338
|
|
Some Darwin corefiles can have the pc/fp/sp/lr in the
live register context signed with pointer authentication;
this patch changes RegisterContextUnwind to strip those
bits off of those values as we try to walk the stack.
Differential Revision: https://reviews.llvm.org/D152861
rdar://109185291
|
|
There is a failure where we somehow get an invalid register
number being used to calculate the canonical frame address,
and this ends up with lldb crashing with a null deref because it
assumes that it is always able to find information about that
register.
This patch adds a check for a failure to get a register, and
declares the frame invalid in that case, with some additional
logging or an assert for debug builds.
Differential Revision: https://reviews.llvm.org/D143232
rdar://104428038
|
|
Improve LLDB reliability by fixing the following "uninitialized variables" static code inspection warnings from
scan.coverity.com:
1476275, 1274012, 1455035, 1364789, 1454282
1467483, 1406152, 1406255, 1454837, 1454416
1467446, 1462022, 1461909, 1420566, 1327228
1367767, 1431254, 1467299, 1312678, 1431780
1454731, 1490403
Differential Revision: https://reviews.llvm.org/D130528
|
|
scan. Part 2"
This reverts commit b9aedd94e6796e4b4866ab4c091b736b3db58cb7.
|
|
Improve LLDB reliability by fixing the following "uninitialized variables" static code inspection warnings from
scan.coverity.com:
1476275, 1274012, 1455035, 1364789, 1454282
1467483, 1406152, 1406255, 1454837, 1454416
1467446, 1462022, 1461909, 1420566, 1327228
1367767, 1431254, 1467299, 1312678, 1431780
1454731, 1490403
Differential Revision: https://reviews.llvm.org/D130528
|
|
This reland 227dffd0b6d78154516ace45f6ed28259c7baa48 and
562c3467a6738aa89203f72fc1d1343e5baadf3c with failed api tests fixed by keeping
function base file addres in DWARFExpressionList.
|
|
This reverts commit 227dffd0b6d78154516ace45f6ed28259c7baa48 and its
follow up 562c3467a6738aa89203f72fc1d1343e5baadf3c because it breaks a
bunch of tests on GreenDragon:
https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/45155/
|
|
Differential Revision: https://reviews.llvm.org/D125509
|
|
When picking the UnwindPlan row to use to backtrace,
off of the zeroth frame, decrement the return pc so
we're in the address range of the call instruction.
If this is a noretrun function call, the instruction
at the "return address" is likely an entirely different
basic block with possibly very different unwind rules,
and this can cause the backtrace to be incorrect.
Differential Revision: https://reviews.llvm.org/D124957
rdar://84651805
|
|
Currently, all data buffers are assumed to be writable. This is a
problem on macOS where it's not allowed to load unsigned binaries in
memory as writable. To be more precise, MAP_RESILIENT_CODESIGN and
MAP_RESILIENT_MEDIA need to be set for mapped (unsigned) binaries on our
platform.
Binaries are mapped through FileSystem::CreateDataBuffer which returns a
DataBufferLLVM. The latter is backed by a llvm::WritableMemoryBuffer
because every DataBuffer in LLDB is considered to be writable. In order
to use a read-only llvm::MemoryBuffer I had to split our abstraction
around it.
This patch distinguishes between a DataBuffer (read-only) and
WritableDataBuffer (read-write) and updates LLDB to use the appropriate
one.
rdar://74890607
Differential revision: https://reviews.llvm.org/D122856
|
|
We already have a VASprintf function for this purpose, so I'm switching
the remaining few users to that.
|
|
Most of our code was including Log.h even though that is not where the
"lldb" log channel is defined (Log.h defines the generic logging
infrastructure). This worked because Log.h included Logging.h, even
though it should.
After the recent refactor, it became impossible the two files include
each other in this direction (the opposite inclusion is needed), so this
patch removes the workaround that was put in place and cleans up all
files to include the right thing. It also renames the file to LLDBLog to
better reflect its purpose.
|
|
|
|
Identified with readability-redundant-string-init.
|
|
This adds a specific unwind plan for AArch64 Linux sigreturn frames.
Previously we assumed that the fp would be valid here but it is not.
https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/vdso/sigreturn.S
On Ubuntu Bionic it happened to point to an old frame info which meant
you got what looked like a correct backtrace. On Focal, the info is
completely invalid. (probably due to some code shuffling in libc)
This adds an UnwindPlan that knows that the sp in a sigreturn frame
points to an rt_sigframe from which we can offset to get saved
sp and pc values to backtrace correctly.
Based on LibUnwind's change: https://reviews.llvm.org/D90898
A new test is added that sets all compares the frames from the initial
signal catch to the handler break. Ensuring that the stack/frame pointer,
function name and register values match.
(this test is AArch64 Linux specific because it's the only one
with a specific unwind plan for this situation)
Fixes https://bugs.llvm.org/show_bug.cgi?id=52165
Reviewed By: omjavaid, labath
Differential Revision: https://reviews.llvm.org/D112069
|
|
The Swift async task pointers are signed on arm64e and we need to fixup
the addresses in the CFA and DWARF expressions.
|
|
Implement FixCodeAddress and FixDataAddress for ABIMacOSX_arm64 and
ABISysV_arm64 and add missing calls to RegisterContextUnwind. We need
this to unwind on Apple Silicon where libraries like libSystem are
arm64e even when the program being debugged is arm64.
Differential revision: https://reviews.llvm.org/D100521
|
