This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
Add:
- `EmulateInstructionRISCV`, which can be used for riscv32 and riscv64.
- Add unittests for EmulateInstructionRISCV.
Note: Compressed instructions set (RVC) was still not supported in this patch.
Reviewed By: DavidSpickett
Differential Revision: https://reviews.llvm.org/D131759
In this switch case we didn't handle possible errors in `ResumeThread()`, it's hard to get helpful information when it goes wrong.
Reviewed By: DavidSpickett
Differential Revision: https://reviews.llvm.org/D131946
Currently, lldb-server was opening the executable file to determine the
process architecture (to differentiate between 32 and 64 bit
architecture flavours). This isn't a particularly trustworthy source of
information (the file could have been changed since the process was
started) and it is not always available (file could be deleted or
otherwise inaccessible).
Unfortunately, ptrace does not give us a direct API to access the
process architecture, but we can still infer it via some of its
responses -- given that the general purpose register set of 64-bit
applications is larger [citation needed] than the GPR set of 32-bit
ones, we can just ask for the application GPR set and check its size.
This is what this patch does.
Differential Revision: https://reviews.llvm.org/D130985
Implement support for the "t" action that is used to stop a thread.
Normally this action is used only in non-stop mode. However, there's
no technical reason why it couldn't be also used in all-stop mode,
e.g. to express "resume all threads except ..." (`t:...;c`).
While at it, add a more complete test for vCont correctly resuming
a subset of program's threads.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D126983
- Add collection of context switches per cpu grouped with the per-cpu intel pt traces.
- Move the state handling from the interl pt trace class to the PerfEvent one.
- Add support for stopping and enabling perf event groups.
- Return context switch entries as part of the jLLDBTraceGetState response.
- Move the triggers of whenever the process stopped or resumed. Now the will-resume notification is in a better location, which will ensure that we'll capture the instructions that will be executed.
- Remove IntelPTSingleBufferTraceUP. The unique pointer was useless.
- Add unit tests
Differential Revision: https://reviews.llvm.org/D125897
When tracing on per-core mode, we are tracing all processes, which means
that after hitting a breakpoint, our process will stop running (thus
producing no more tracing data) but other processes will continue
writing to our trace buffers. This causes a big data loss for our trace.
As a way to remediate this, I'm adding some logic to pause and unpause
tracing based on the target's state. The earlier we do it the better,
however, I'm not adding the trigger at the earliest possible point for
simplicity of this diff. Later we can improve that part.
Differential Revision: https://reviews.llvm.org/D124962
This diffs implements per-core tracing on lldb-server. It also includes tests that ensure that tracing can be initiated from the client and that the jLLDBGetState ppacket returns the list of trace buffers per core.
This doesn't include any decoder changes.
Finally, this makes some little changes here and there improving the existing code.
A specific piece of code that can't reliably be tested is when tracing
per core fails due to permissions. In this case we add a
troubleshooting message and this is the manual test:
```
/proc/sys/kernel/perf_event_paranoid set to 1
(lldb) process trace start --per-core-tracing error: perf event syscall failed: Permission denied
You might need that /proc/sys/kernel/perf_event_paranoid has a value of 0 or -1.
``
Differential Revision: https://reviews.llvm.org/D124858
I'm refactoring IntelPTThreadTrace into IntelPTSingleBufferTrace so that it can
both single threads or single cores. In this diff I'm basically renaming the
class, moving it to its own file, and removing all the pieces that are not used
along with some basic cleanup.
Differential Revision: https://reviews.llvm.org/D124648
This patch handles the situation where the main thread exits (through
the SYS_exit syscall). In this case, the process as a whole continues
running until all of the other threads exit, or one of them issues an
exit_group syscall.
The patch consists of two changes:
- a moderate redesign of the handling of thread exit (WIFEXITED) events.
Previously, we were removing (forgetting) a thread once we received
the WIFEXITED (or WIFSIGNALED) event. This was problematic for the
main thread, since the main thread WIFEXITED event (which is better thought
of as a process-wide event) gets reported only after the entire process
exits. This resulted in deadlocks, where we were waiting for the
process to stop (because we still considered the main thread "live").
This patch changes the logic such that the main thread is removed as
soon as its PTRACE_EVENT_EXIT (the pre-exit) event is received. At
this point we can consider the thread gone (for most purposes). As a
corrolary, I needed to add special logic to catch process-wide exit
events in the cases where we don't have the main thread around.
- The second part of the patch is the removal of the assumptions that
the main thread is always available. This generally meant replacing
the uses of GetThreadByID(process_id) with GetCurrentThread() in
various process-wide operations (such as memory reads).
Differential Revision: https://reviews.llvm.org/D122716
- Rename IntelPTManager class and files to IntelPTCollector
- Change GetTimestampCounter API to general trace counter API,
GetCounter
Differential Revision: https://reviews.llvm.org/D121711
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.
This better describes the intent of the method. Which for AArch64
is removing the top byte which includes the memory tags.
It does not include pointer signatures, for those we need to use
the ABI plugin. The rename makes this a little more clear.
It's a bit awkward that the memory tag manager is removing the whole
top byte not just the memory tags but it's an improvement for now.
Reviewed By: omjavaid
Differential Revision: https://reviews.llvm.org/D117671
Implement the qXfer:siginfo:read that is used to read the siginfo_t
(extended signal information) for the current thread. This is currently
implemented on FreeBSD and Linux.
Differential Revision: https://reviews.llvm.org/D117113
D116372, while fixing one kind of a race, ended up creating a new one.
The new issue could occur when one inferior thread exits while another
thread initiates termination of the entire process (exit_group(2)).
With some bad luck, we could start processing the exit notification
(PTRACE_EVENT_EXIT) only to have the become unresponsive (ESRCH) in the
middle of the MonitorCallback function. This function would then delete
the thread from our list even though it wasn't completely dead (it stays
zombified until we read the WIFEXITED event). The linux kernel will not
deliver the exited event for the entire process until we process
individual thread exits.
In a pre-D116372 world, this wouldn't be a problem because we would read
this event (even though we would not know what to do with it) with
waitpid(-1). Now, when we issue invididual waitpids, this event will
never be picked up, and we end up hanging.
The fix for this is actually quite simple -- don't delete the thread in
this situation. The thread will be deleted when the WIFEXITED event
comes.
This situation was kind of already tested by
TestCreateDuringInstructionStep (which is how I found this problem), but
it was mostly accidental, so I am also creating a dedicated test which
reproduces this situation.
The lldb-server code is currently set up in a way that each
NativeProcess instance does its own waitpid handling. This works fine
for BSDs, where the code can do a waitpid(process_id), and get
information for all threads in that process.
The situation is trickier on linux, because waitpid(pid) will only
return information for the main thread of the process (one whose tid ==
pid). For this reason the linux code does a waitpid(-1), to get
information for all threads. This was fine while we were supporting just
a single process, but becomes a problem when we have multiple processes
as they end up stealing each others events.
There are two possible solutions to this problem:
- call waitpid(-1) centrally, and then dispatch the events to the
appropriate process
- have each process call waitpid(tid) for all the threads it manages
This patch implements the second approach. Besides fitting better into
the existing design, it also has the added benefit of ensuring
predictable ordering for thread/process creation events (which come in
pairs -- one for the parent and one for the child). The first approach
OTOH, would make this ordering even more complicated since we would
have to keep the half-threads hanging in mid-air until we find the
process we should attach them to.
The downside to this approach is an increased number of syscalls (one
waitpid for each thread), but I think we're pretty far from optimizing
things like this, and so the cleanliness of the design is worth it.
The included test reproduces the circumstances which should demonstrate
the bug (which manifests as a hung test), but I have not been able to
get it to fail. The only place I've seen this failure modes are very
rare hangs in the thread sanitizer tests (tsan forks an addr2line
process to produce its error messages).
Differential Revision: https://reviews.llvm.org/D116372
The MonitorCallback function was assuming that the "exited" argument is
set whenever a thread exits, but the caller was only setting that flag
for the main thread.
This patch deletes the argument altogether, and lets MonitorCallback
compute what it needs itself.
This is almost NFC, since previously we would end up in the
"GetSignalInfo failed for unknown reasons" branch, which was doing the
same thing -- forgetting about the thread.
.. and reduce the scope of others. They don't follow llvm coding
standards (which say they should be used only when the same effect
cannot be achieved with the static keyword), and they set a bad example.
This is implemented using the QMemTags packet, as specified
by GDB in:
https://sourceware.org/gdb/current/onlinedocs/gdb/General-Query-Packets.html#General-Query-Packets
(recall that qMemTags was previously added to read tags)
On receipt of a valid packet lldb-server will:
* align the given address and length to granules
(most of the time lldb will have already done this
but the specification doesn't guarantee it)
* Repeat the supplied tags as many times as needed to cover
the range. (if tags > range we just use as many as needed)
* Call ptrace POKEMTETAGS to write the tags.
The ptrace step will loop just like the tag read does,
until all tags are written or we get an error.
Meaning that if ptrace succeeds it could be a partial write.
So we call it again and if we then get an error, return an error to
lldb.
We are not going to attempt to restore tags after a partial
write followed by an error. This matches the behaviour of the
existing memory writes.
The lldb-server tests have been extended to include read and
write in the same test file. With some updated function names
since "qMemTags" vs "QMemTags" isn't very clear when they're
next to each other.
Reviewed By: omjavaid
Differential Revision: https://reviews.llvm.org/D105180
This adds memory tag reading using the new "qMemTags"
packet and ptrace on AArch64 Linux.
This new packet is following the one used by GDB.
(https://sourceware.org/gdb/current/onlinedocs/gdb/General-Query-Packets.html)
On AArch64 Linux we use ptrace's PEEKMTETAGS to read
tags and we assume that lldb has already checked that the
memory region actually has tagging enabled.
We do not assume that lldb has expanded the requested range
to granules and expand it again to be sure.
(although lldb will be sending aligned ranges because it happens
to need them client side anyway)
Also we don't assume untagged addresses. So for AArch64 we'll
remove the top byte before using them. (the top byte includes
MTE and other non address data)
To do the ptrace read NativeProcessLinux will ask the native
register context for a memory tag manager based on the
type in the packet. This also gives you the ptrace numbers you need.
(it's called a register context but it also has non register data,
so it saves adding another per platform sub class)
The only supported platform for this is AArch64 Linux and the only
supported tag type is MTE allocation tags. Anything else will
error.
Ptrace can return a partial result but for lldb-server we will
be treating that as an error. To succeed we need to get all the tags
we expect.
(Note that the protocol leaves room for logical tags to be
read via qMemTags but this is not going to be implemented for lldb
at this time.)
Reviewed By: omjavaid
Differential Revision: https://reviews.llvm.org/D95601
This feature "memory-tagging+" indicates that lldb-server
supports memory tagging packets. (added in a later patch)
We check HWCAP2_MTE to decide whether to enable this
feature for Linux.
Reviewed By: omjavaid
Differential Revision: https://reviews.llvm.org/D97282
The C headers are deprecated so as requested in D102845, this is replacing them
all with their (not deprecated) C++ equivalent.
Reviewed By: shafik
Differential Revision: https://reviews.llvm.org/D103084
Remove hardcoded platform list for QPassSignals, qXfer:auxv:read
and qXfer:libraries-svr4:read and instead query the process plugin
via the GetSupportedExtensions() API.
Differential Revision: https://reviews.llvm.org/D101241
Enable reporting fork/vfork events to the server when supported.
At this moment, this is used only to test the server code, as real
client does not report fork-events and vfork-events as supported.
Differential Revision: https://reviews.llvm.org/D100208
This commit has caused the following tests to be flaky:
TestThreadSpecificBpPlusCondition.py
TestExitDuringExpression.py
The exact cause is not known yet, but since both tests deal with
threads, my guess is it has something to do with the tracking of
creation of new threads (which the commit touches upon).
This reverts the following commits:
d01bff8cbd,
ba62ebc48e,
e761b6b4c5,
a345419ee0.
In all this time, we've never used more than one delegate. The logic to
support multiple delegates is therefore untested, and becomes
particularly unwieldy once we need to support multiple processes.
Just remove it.
Watch for fork(2)/vfork(2) (also fork/vfork-style clone(2) on Linux)
notifications and explicitly detach the forked child process, and add
initial tests for these cases. The code covers FreeBSD, Linux
and NetBSD process plugins. There is no new user-visible functionality
provided -- this change lays foundations over subsequent work on fork
support.
Differential Revision: https://reviews.llvm.org/D98822
This implements the interactive trace start and stop methods.
This diff ended up being much larger than I anticipated because, by doing it, I found that I had implemented in the beginning many things in a non optimal way. In any case, the code is much better now.
There's a lot of boilerplate code due to the gdb-remote protocol, but the main changes are:
- New tracing packets: jLLDBTraceStop, jLLDBTraceStart, jLLDBTraceGetBinaryData. The gdb-remote packet definitions are quite comprehensive.
- Implementation of the "process trace start|stop" and "thread trace start|stop" commands.
- Implementaiton of an API in Trace.h to interact with live traces.
- Created an IntelPTDecoder for live threads, that use the debugger's stop id as checkpoint for its internal cache.
- Added a functionality to stop the process in case "process tracing" is enabled and a new thread can't traced.
- Added tests
I have some ideas to unify the code paths for post mortem and live threads, but I'll do that in another diff.
Differential Revision: https://reviews.llvm.org/D91679
Introduce mips64 support to match the legacy FreeBSD plugin. Similarly
to the legacy plugin, the code does not support FPU registers at the
moment. The support for them will be submitted separately as it
requires changes to the register context shared by both plugins.
This also includes software single-stepping support that is moved from
the Linux plugin into a common Utility class. The FreeBSD code also
starts explicitly ignoring EINVAL from PT_CLEARSTEP since this is easier
to implement than checking whether hardware single-stepping were used.
Differential Revision: https://reviews.llvm.org/D95802
This extends the "memory region" command to
show tagged regions on AArch64 Linux when the MTE
extension is enabled.
(lldb) memory region the_page
[0x0000fffff7ff8000-0x0000fffff7ff9000) rw-
memory tagging: enabled
This is done by adding an optional "flags" field to
the qMemoryRegion packet. The only supported flag is
"mt" but this can be extended.
This "mt" flag is read from /proc/{pid}/smaps on Linux,
other platforms will leave out the "flags" field.
Where this "mt" flag is received "memory region" will
show that it is enabled. If it is not or the target
doesn't support memory tagging, the line is not shown.
(since majority of the time tagging will not be enabled)
Testing is added for the existing /proc/{pid}/maps
parsing and the new smaps parsing.
Minidump parsing has been updated where needed,
though it only uses maps not smaps.
Target specific tests can be run with QEMU and I have
added MTE flags to the existing helper scripts.
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D87442
Depends on D89283.
The goal of this packet (jTraceGetSupportedType) is to be able to query the gdb-server for the tracing technology that can work for the current debuggeer, which can make the user experience simpler but allowing the user to simply type
thread trace start
to start tracing the current thread without even telling the debugger to use "intel-pt", for example. Similarly, `thread trace start [args...]` would accept args beloging to the working trace type.
Also, if the user typed
help thread trace start
We could directly show the help information of the trace type that is supported for the target, or mention instead that no tracing is supported, if that's the case.
I added some simple tests, besides, when I ran this on my machine with intel-pt support, I got
$ process plugin packet send "jTraceSupportedType"
packet: jTraceSupportedType
response: {"description":"Intel Processor Trace","pluginName":"intel-pt"}
On a machine without intel-pt support, I got
$ process plugin packet send "jTraceSupportedType"
packet: jTraceSupportedType
response: E00;
Reviewed By: clayborg, labath
Differential Revision: https://reviews.llvm.org/D90490
This patch adds support for the _M and _m gdb-remote packets, which
(de)allocate memory in the inferior. This works by "injecting" a
m(un)map syscall into the inferior. This consists of:
- finding an executable page of memory
- writing the syscall opcode to it
- setting up registers according to the os syscall convention
- single stepping over the syscall
The advantage of this approach over calling the mmap function is that
this works even in case the mmap function is buggy or unavailable. The
disadvantage is it is more platform-dependent, which is why this patch
only works on X86 (_32 and _64) right now. Adding support for other
linux architectures should be easy and consist of defining the
appropriate syscall constants. Adding support for other OSes depends on
the its ability to do a similar trick.
Differential Revision: https://reviews.llvm.org/D89124
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
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
Differential revision: https://reviews.llvm.org/D66259
llvm-svn: 368933
Summary:
Due to a logic error, lldb-server ended up asserting/crashing every time
the debugged process attempted an execve(). This fixes the error, and
extends TestExec to work on other platforms too. The "extension"
consists of avoiding non-standard posix_spawn extensions and using the
classic execve() call, which should be available on any platform that
actually supports re-execing. I change the test decorator from
@skipUnlessDarwin to @skipIfWindows.
Reviewers: clayborg, jasonmolenda
Subscribers: lldb-commits
Differential Revision: https://reviews.llvm.org/D65207
llvm-svn: 366985
Kazu Hirata