@dmpots and I were investigating a crash when he was developing LLDB
earlier. When I loaded the core I was surprised to see LLDB didn't have
information for the SI_CODE. Upon inspection we had an si_code of `128`,
which is the decimal of SI_KERNEL at `0x80`.
These were overlooked in my last addition of the negative si_codes, and
this patch adds SI_USER and SI_KERNEL to the list, covering us for all
the codes available to all signals.
[Linux reference
link](74b4cc9b87/include/uapi/asm-generic/siginfo.h (L175))
I kept the code naming the same as what is defined in the Linux source
code. SI_KERNEL to my understanding usually indicates something went
awry in the Kernel itself, but I think adding that additional detail
would not be helpful to most users. @DavidSpickett I'd appreciate your
insight into that.
After some debugging, I found out ProcessELFCore never updates the
platform. I've updated ProcessElfCore to set the arch and platform
before we parse the Notes.
Recently, I was on an issue that generated a large number of Coredumps,
and every time in both LLDB and GDB the signal was just `SIGSEGV`.
This was frustrating because we would expect a `SIGSEGV` to have an
address, or ideally even bounds. After some digging I found the
`si_code` consistently was -6. With some help from
[@cdown](https://github.com/cdown), we found neither LLDB or GDB
supports the si_codes sent from [user
space](https://github.com/torvalds/linux/blob/master/include/uapi/asm-generic/siginfo.h#L185).
Excerpted from the sigaction man page.
```
For a regular signal, the following list shows the values which
can be placed in si_code for any signal, along with the reason
that the signal was generated.
```
For which I added all of the si_codes to every Linux signal. Now for the
Coredump that triggered this whole investigation we get the accurate and
now very informative summary.
<img width="524" alt="image"
src="https://github.com/user-attachments/assets/5149f781-ef21-4491-a077-8fac862fbc20"
/>
Additionally from @labath's suggestion to move this to platform and
leverage the existing `getSiginfo()` call on thread, we can now inspect
the siginfo struct itself via `thread siginfo`. Giving us another
towards GDB parity on elf cores.
Now, because we do not support mips debugging, if we compile LLVM on
mips target, would report error `static assertion failed:Value mismatch
for signal number SIGBUS`, so add this condition to avoid error.
This will be sent by Arm's Guarded Control Stack extension when an
invalid return is executed.
The signal does have an address we could show, but it's the PC at which
the fault occured. The debugger has plenty of ways to show you that
already, so I've left it out.
```
(lldb) c
Process 460 resuming
Process 460 stopped
* thread #1, name = 'test', stop reason = signal SIGSEGV: control protection fault
frame #0: 0x0000000000400784 test`main at main.c:57:1
54 afunc();
55 printf("return from main\n");
56 return 0;
-> 57 }
(lldb) dis
<...>
-> 0x400784 <+100>: ret
```
The new test case generates the signal by corrupting the link register
then attempting to return. This will work whether we manually enable GCS
or the C library does it for us.
(in the former case you could just return from main and it would fault)
The high level goal of this change is to remove lldbTarget's dependency
on lldbPluginProcessUtility. The reason for this existing dependency is
so that we can create the appropriate UnixSignals object based on an
ArchSpec. Instead of using the ArchSpec, we can instead take advantage
of the Platform associated with the current Target.
This is accomplished by adding a new method to Platform,
CreateUnixSignals, which will create the correct UnixSignals object for
us. We then can use `Platform::GetUnixSignals` and rely on that to give
us the correct signals as needed.
Differential Revision: https://reviews.llvm.org/D146263
By adding signal codes to UnixSignals and adding a new function
where you can get a string with optional address and bounds.
Added signal codes to the Linux, FreeBSD and NetBSD signal sets.
I've checked the numbers against the relevant sources.
Each signal code has a code number, description and printing options.
By default you just get the descripton, you can opt into adding either
a fault address or bounds information.
Bounds signals we'll use the description, unless we have the bounds
values in which case we say whether it is an upper or lower bound
issue.
GetCrashReasonString remains in CrashReason because we need it to
be compiled only for platforms with siginfo_t. Ideally it would
move into NativeProcessProtocol, but that is also used
by NativeRegisterContextWindows, where there would be no siginfo_t.
Reviewed By: JDevlieghere
Differential Revision: https://reviews.llvm.org/D146044
Except for the few people actually debugging shells, stopping on a
SIGCONT doesn't add any value. And for people trying to run tests
under the debugger, stopping here is actively inconvenient. So this
patch switches the default behavior to not stop.
Differential Revision: https://reviews.llvm.org/D89019
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
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
This patch removes the comments grouping header includes. They were
added after running IWYU over the LLDB codebase. However they add little
value, are often outdates and burdensome to maintain.
llvm-svn: 346626
*** to conform to clang-format’s LLVM style. This kind of mass change has
*** two obvious implications:
Firstly, merging this particular commit into a downstream fork may be a huge
effort. Alternatively, it may be worth merging all changes up to this commit,
performing the same reformatting operation locally, and then discarding the
merge for this particular commit. The commands used to accomplish this
reformatting were as follows (with current working directory as the root of
the repository):
find . \( -iname "*.c" -or -iname "*.cpp" -or -iname "*.h" -or -iname "*.mm" \) -exec clang-format -i {} +
find . -iname "*.py" -exec autopep8 --in-place --aggressive --aggressive {} + ;
The version of clang-format used was 3.9.0, and autopep8 was 1.2.4.
Secondly, “blame” style tools will generally point to this commit instead of
a meaningful prior commit. There are alternatives available that will attempt
to look through this change and find the appropriate prior commit. YMMV.
llvm-svn: 280751
Summary:
Realtime signals generally do not represent an error condition in an application but are more
like a regular means of IPC. As such, we shouldn't interrupt an application whenever it recieves
one. If any application will use these signals, it will probably use them a lot, rendering it's
debugging tiresome if we stopped at every signal. Furthermore, these signals are likely to be used
in a low level library, and the programmer may not even be aware of their presence.
For these reasons, I am switching the default disposition of realtime signals on all supported
platforms (i.e. Linux and Freebsd) to no-stop, no-notify. Any user still wishing to receive these
signals can always change the default to suit his needs.
Reviewers: ovyalov, emaste
Subscribers: lldb-commits, emaste
Differential Revision: http://reviews.llvm.org/D12795
llvm-svn: 247537
Summary:
- Consolidate Unix signals selection in UnixSignals.
- Make Unix signals available from platform.
- Add jSignalsInfo packet to retrieve Unix signals from remote platform.
- Get a copy of the platform signal for each remote process.
- Update SB API for signals.
- Update signal utility in test suite.
Reviewers: ovyalov, clayborg
Subscribers: chaoren, jingham, labath, emaste, tberghammer, lldb-commits
Differential Revision: http://reviews.llvm.org/D11094
llvm-svn: 242101
Summary: This enables correct handling of real time signals by lldb.
Test Plan: Added a test that verifies handling of SIGRTMIN
Reviewers: tberghammer, ovyalov
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D9911
llvm-svn: 238009
Summary:
SIGPROF is used for profiling processes (with google-perftools for
instance), which results in the inferior receiving a SIGPROF from the
kernel every few milliseconds. Instead of stopping the debugging session
and notifying the user of this, we should just pass the signal and keep
running.
This follows the behavior we have in UnixSignals.cpp.
Test Plan: Run LLDB on linux with a binary using google-perftools, see that execution gets interrupted all the time because we receive SIGPROF. Apply the patch, everything works fine.
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D5953
llvm-svn: 221011
Also moves NativeRegisterContextLinux* files into the Linux directory.
These, like NativeProcessLinux, should only be built on Linux or a cross
compiler with proper headers.
llvm-svn: 212074
This change brings in lldb-gdbserver (llgs) specifically for Linux x86_64.
(More architectures coming soon).
Not every debugserver option is covered yet. Currently
the lldb-gdbserver command line can start unattached,
start attached to a pid (process-name attach not supported yet),
or accept lldb attaching and launching a process or connecting
by process id.
The history of this large change can be found here:
https://github.com/tfiala/lldb/tree/dev-tfiala-native-protocol-linux-x86_64
Until mid/late April, I was not sharing the work and continued
to rebase it off of head (developed via id tfiala@google.com). I switched over to
user todd.fiala@gmail.com in the middle, and once I went to github, I did
merges rather than rebasing so I could share with others.
llvm-svn: 212069
