Fix a bug where UnwindAssemblyInstEmulation would confuse which
register is used to compute the Canonical Frame Address after it
had branched over a mid-function epilogue (where the CFA reg changes
from $fp to $sp in the process of epiloguing). Reinstate the
correct CFA register after we forward the unwind rule for branch
targets. The failure mode was that UnwindAssemblyInstEmulation
would think CFA was set in terms of $sp after one of these epilogues,
and if it sees modifications to $sp after the branch target, it would
change the CFA offset in the unwind rule -- even though the CFA is
defined in terms of $fp and the $sp changes are irrelevant to correct
calculation.
<rdar://problem/60300528>
Differential Revision: https://reviews.llvm.org/D78077
This patch changes the way we initialize and terminate the plugins in
the system initializer. It uses an approach similar to LLVM's
TARGETS_TO_BUILD with a def file that enumerates the plugins.
The previously landed patch got reverted because it was lacking:
(1) A plugin definition for the Objective-C language runtime,
(2) The dependency between the Static and WASM dynamic loader,
(3) Explicit initialization of ScriptInterpreterNone for lldb-test.
All issues have been addressed in this patch.
Differential revision: https://reviews.llvm.org/D73067
This patch changes the way we initialize and terminate the plugins in
the system initializer. It uses an approach similar to LLVM's
TARGETS_TO_BUILD with a def file that enumerates the plugins.
Differential revision: https://reviews.llvm.org/D73067
Summary:
A *.cpp file header in LLDB (and in LLDB) should like this:
```
//===-- TestUtilities.cpp -------------------------------------------------===//
```
However in LLDB most of our source files have arbitrary changes to this format and
these changes are spreading through LLDB as folks usually just use the existing
source files as templates for their new files (most notably the unnecessary
editor language indicator `-*- C++ -*-` is spreading and in every review
someone is pointing out that this is wrong, resulting in people pointing out that this
is done in the same way in other files).
This patch removes most of these inconsistencies including the editor language indicators,
all the different missing/additional '-' characters, files that center the file name, missing
trailing `===//` (mostly caused by clang-format breaking the line).
Reviewers: aprantl, espindola, jfb, shafik, JDevlieghere
Reviewed By: JDevlieghere
Subscribers: dexonsmith, wuzish, emaste, sdardis, nemanjai, kbarton, MaskRay, atanasyan, arphaman, jfb, abidh, jsji, JDevlieghere, usaxena95, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D73258
Unwind plan augmentation should compute the plan row at offset x from
the instruction before offset x, but currently we compute it from the
instruction at offset x. Note that this behavior is a regression
introduced when moving the x86 assembly inspection engine to its own
file
(1c9858b298 (diff-375a2be066db6f34bb9a71442c9b71fcL913));
the original version handled this properly by copying the previous
instruction out before advancing the instruction pointer.
The relevant bug with more info is here: https://bugs.llvm.org/show_bug.cgi?id=43561
Differential Revision: https://reviews.llvm.org/D68454
Patch by Jaroslav Sevcik <jarin@google.com>.
llvm-svn: 374342
The x86 assembly inspection engine has code to support detecting a
mid-function epilogue that ends in a RET instruction; add support for
recognizing an epilogue that ends in a JMP, and add a check that the
unwind state has been restored to the original stack setup; reinstate
the post-prologue unwind state after this JMP instruction.
The assembly inspection engine used for other architectures,
UnwindAssemblyInstEmulation, detects mid-function epilogues by
tracking branch instructions within the function and "forwards"
the current unwind state to the targets of the branches. If
an epilogue unwinds the stack and exits, followed by a branch
target, we get back to the correct unwind state. The x86
unwinder should move to this same algorithm, or possibly even
look at implementing an x86 instruction emulation plugin and
get UnwindAssemblyInstEmulation to work for x86 too. I added
a branch instruction recognizier method that will be necessary
if we want to switch the algorithm.
Differential Revision: https://reviews.llvm.org/D62764
<rdar://problem/51074422>
llvm-svn: 362456
Unlike std::make_unique, which is only available since C++14,
std::make_shared is available since C++11. Not only is std::make_shared
a lot more readable compared to ::reset(new), it also performs a single
heap allocation for the object and control block.
Differential revision: https://reviews.llvm.org/D57990
llvm-svn: 353764
Summary: Replace 0xc9 (LEAVE) with 0xcb (RETF) in ret_pattern_p(). Also put 0xc3 first, since it is the most common form and will match first.
Reviewers: jasonmolenda
Reviewed By: jasonmolenda
Subscribers: labath, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D57928
llvm-svn: 353643
instructions
Summary: This patch makes `x86AssemblyInspectionEngine` to process zero value of
the `B` field of the `REX` prefix in a correct way for `PUSH` and `POP`
instructions. MSVC sometimes emits `pushq %rbp` instruction as `0x40 0x55`, and
it was not parsed correctly before.
Reviewers: jasonmolenda, labath
Reviewed By: jasonmolenda, labath
Subscribers: abidh, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D57745
llvm-svn: 353281
to reflect the new license.
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: 351636
Summary:
This patch fixes issues with a stack realignment.
MSVC maintains two frame pointers (`ebx` and `ebp`) for a realigned stack - one
is used for access to function parameters, while another is used for access to
locals. To support this the patch:
- adds an alternative frame pointer (`ebx`);
- considers stack realignment instructions (e.g. `and esp, -32`);
- along with CFA (Canonical Frame Address) which point to the position next to
the saved return address (or to the first parameter on the stack) introduces
AFA (Aligned Frame Address) which points to the position of the stack pointer
right after realignment. AFA is used for access to registers saved after the
realignment (see the test);
Here is an example of the code with the realignment:
```
struct __declspec(align(256)) OverAligned {
char c;
};
void foo(int foo_arg) {
OverAligned oa_foo = { 1 };
auto aaa_foo = 1234;
}
void bar(int bar_arg) {
OverAligned oa_bar = { 2 };
auto aaa_bar = 5678;
foo(1111);
}
int main() {
bar(2222);
return 0;
}
```
and here is the `bar` disassembly:
```
push ebx
mov ebx, esp
sub esp, 8
and esp, -100h
add esp, 4
push ebp
mov ebp, [ebx+4]
mov [esp+4], ebp
mov ebp, esp
sub esp, 200h
mov byte ptr [ebp-200h], 2
mov dword ptr [ebp-4], 5678
push 1111 ; foo_arg
call j_?foo@@YAXH@Z ; foo(int)
add esp, 4
mov esp, ebp
pop ebp
mov esp, ebx
pop ebx
retn
```
Reviewers: labath, zturner, jasonmolenda, stella.stamenova
Reviewed By: jasonmolenda
Subscribers: abidh, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D53435
llvm-svn: 345577
Summary: We never delete the created instances, so those test fail with the memory sanitizer.
Reviewers: jasonmolenda
Reviewed By: jasonmolenda
Subscribers: aemerson, javed.absar, kristof.beyls, lldb-commits
Differential Revision: https://reviews.llvm.org/D42336
llvm-svn: 323076
The rationale here is that ArchSpec is used throughout the codebase,
including in places which should not depend on the rest of the code in
the Core module.
This commit touches many files, but most of it is just renaming of
#include lines. In a couple of cases, I removed the #include ArchSpec
line altogether, as the file was not using it. In one or two places,
this necessitated adding other #includes like lldb-private-defines.h.
llvm-svn: 318048
Summary:
ArchSpec::SetTriple was taking a Platform as an argument, and used it to
fill in missing pieces of the specified triple. I invert the dependency
by moving this code to other classes. For this purpose, I've created
three new functions.
- HostInfo::GetAugmentedArchSpec: fills in the triple using the host
platform (this used to be implemented by passing a null platform
pointer). By putting this code in the Host module, we can provide a
way to anyone who does not have a platform instance (lldb-server) an
easy way to get Host data.
- Platform::GetAugmentedArchSpec: if you have a platform instance, you
can call this to let it fill in the triple.
- static Platform::GetAugmentedArchSpec: implements the "if platform ==
0 then use_host() else use_platform()" part.
Reviewers: zturner, jingham, clayborg
Subscribers: mgorny, javed.absar, lldb-commits
Differential Revision: https://reviews.llvm.org/D39387
llvm-svn: 316987
blocks of memory, and if the final bytes of that block look like a long
x86 instruction, it can cause the llvm disassembler to read past the end
of the buffer. Use the maximum allowed instruction length that we pass
to the llvm disassembler as a way to limit this to the size of the buffer.
An example of how to trigger this is when lldb does a function call, it
puts a breakpoint on the beginning of main() and uses that as the return
address from the function call. When we stop at that location, lldb may
try to find the first frame up the stack. Because this is on the first
instruction of a function, it will get the word-size value at the stack
pointer and assume that this was the caller's pc value. But this is random
stack memory and could point to anything - an object in memory, something
in the data section, whatever. And if we have a symbol for that thing,
we'll try to disassemble it.
This was leading to infrequent crashes in customer scenarios; figured out
what was happening with address sanitizer.
<rdar://problem/30463256>
llvm-svn: 307454
Summary:
The instruction pattern:
and $-16, %esp
sub $imm, %esp
...
lea imm(%ebp), %esp
appears when the compiler is realigning the stack (for example in
main(), or almost everywhere with -mstackrealign switch). The "and"
instruction is very difficult to model, but that's not necessary, as
these frames are always %ebp-based (the compiler also needs a way to
restore the original %esp). Therefore the plans we were generating for
these function were almost correct already. The only place we were doing
it wrong were the last instructions of the epilogue (usually just
"ret"), where we had to revert to %esp-based unwinding, as the %ebp had
been popped already.
This was wrong because our "distance of esp from cfa" counter had picked
up the "sub" instruction (and incremented the counter) but it had not
seen that the register was reset by the "lea" instruction.
This patch fixes that shortcoming, and adds a test for handling
functions like this.
I have not been able to tickle the compiler into producing a 64-bit
function with this pattern, but I don't see a reason why it couldn't
produce it, if it chose to, so I add a x86_64 test as well.
Reviewers: jasonmolenda, tberghammer
Subscribers: lldb-commits
Differential Revision: https://reviews.llvm.org/D34750
llvm-svn: 306666
for floating point registers was not recording them correctly. I needed to
change the EmulateInstructionARM64 unwind plans from using the DWARF
register numbering scheme to using the LLDB register numbering scheme
(because dwarf doesn't define register numbers for the 64-bit "d" registers).
Updated the EmulateInstructionARM64 unit tests to work with the LLDB
register numbering scheme and added a unit test to check the floating
point register spills & restores are correctly recorded.
https://reviews.llvm.org/D25864
<rdar://problem/28745483>
llvm-svn: 285662
prologue, then loads & stores x20 on the stack from a different
location in the middle of the function, and then restores the
reg in the epilogue. The saving/restoring of x20 in the middle
of the function should be ignored.
llvm-svn: 283969
MSVC does not like the declaration of a terminate() function (I guess it looks
too much like std::terminate()). While I'm there, move the setup/teardown code
into the functions gtest provides for that purpose.
llvm-svn: 283870
plan generator.
Fix a small bug in EmulateInstructionARM64::GetFramePointerRegister
which was returning the stack pointer reg instead of fp, prevented
the unwinder from recognizing the switch to using the fp in a
function. (<rdar://problem/28663117>)
Add a new eContextRestoreStackPointer context hint so that the arm64
emulator can flag when the frame pointer value is copied back in to
the stack pointer and that should be used to compute the canonical
frame address again in an epilogue sequence. (<rdar://problem/28704862>)
Small changes to UnwindAssemblyInstEmulation to have a method we can
call without a live process/thread/etc for unit tests.
<rdar://problem/28663117>
<rdar://problem/28704862>
<rdar://problem/28509178>
llvm-svn: 283847
insturction profiling. Add a test that verifies that we reject a
32-bit only instruction in 64-bit (long) mode.
This wraps up all the testing I want to add for
x86AssemblyInspectionEngine.
llvm-svn: 283404
unittests. If I have time, I'd like to see if I can write some
tests of the eh_frame augmentation which is a wholly separate code
path (it seems like maybe it should be rolled into the main instruction
scanning codepath, to be honest, and operate on the generated
UnwindPlan instead of bothering with raw instructions at all).
Outside the eh_frame augmentation, I'm comfortable that this unwind
generator is being tested well now.
llvm-svn: 283186
assembly inspection class is designed to detect. This is only about
half of the instructions that it needs to recognize - I'll complete
this in a separate checkin.
The larger full-function style test cases I'd checked in previously
covered nearly all of these already, but I wanted simpler test cases
too, so if they fail in the future, it will be easier to spot the
issue.
llvm-svn: 283010
'push 0x20(%esp)' which clang can generate when emitting
-fomit-frame-pointer code for 32-bit.
Add a unit test program which includes this instruction.
Also fix a bug in the refactoring/rewrite of the x86 assembly
instruction profiler where I'd hard coded it as a 64-bit disassembler
instead of using the ArchSpec to pick a 32-bit or 64-bit disassembler
from llvm. When the disassembler would hit an instruction
that is invalid in 64-bit mode, it would stop disassembling the function.
This likely led to the TestSBData testsuite failure on linux with 32-bit
i386 and gcc-4.9; I'll test that in a bit.
The newly added unit test program is 32-bit i386 code and it includes
an instruction which is invalid in 64-bit mode so it will catch this.
<rdar://problem/28557876>
llvm-svn: 282991
a large stack frame with lots of spilled registers.
While writing the i386 version of this test, it looks
like I found a bug in the 32-bit instruction profiler
code. I may ned to fix the assembly inspection engine
before I can finish writing that test, so I'm only
committing the 64-bit one tonight.
<rdar://problem/28509178>
llvm-svn: 282683
a linux bot test failure. That one is fixed; hopefully there won't
be any others turned up this time.
The eh_frame augmentation code wasn't working right after the
reorg/rewrite of the classes. It works correctly now for the one
test that was failing - but we'll see what the test bots come up
with.
<rdar://problem/28509178>
llvm-svn: 282659
A testbot found a regression introduced in the testsuite with
the changes in r282565 on Ubuntu (TestStepNoDebug.ReturnValueTestCase).
I'll get this set up on an ubuntu box and figure out what is happening
there -- likely a problem with the eh_frame augmentation, which isn't
used on macosx.
llvm-svn: 282566
x86AssemblyInspectionEngine and the current UnwindAssembly_x86 to
allow for the core engine to be exercised by unit tests.
The UnwindAssembly_x86 class will have access to Targets, Processes,
Threads, RegisterContexts -- it will be working in the full lldb
environment.
x86AssemblyInspectionEngine is layered away from all of that, it is
given some register definitions and a bag of bytes to profile.
I wrote an initial unittest for a do-nothing simple x86_64/i386
function to start with. I'll be adding more.
The x86 assembly unwinder was added to lldb early in its bringup;
I made some modernization changes as I was refactoring the code
to make it more consistent with how we write lldb today.
I also added RegisterContextMinidump_x86_64.cpp to the xcode project
file so I can run the unittests from that.
The testsuite passes with this change, but there was quite a bit of
code change by the refactoring and it's possible there are some
issues. I'll be testing this more in the coming days, but it looks
like it is behaving correctly as far as I can tell with automated
testing.
<rdar://problem/28509178>
llvm-svn: 282565
Jason Molenda