Include the complete list of threads of all running processes
in the FreeBSDKernel plugin. This makes it possible to inspect
the states (including partial register dumps from PCB) of all kernel
and userspace threads at the time of crash, or at the time of reading
/dev/mem first.
Differential Revision: https://reviews.llvm.org/D116255
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
This is a re-submission of 24d2405588
without the hunks in HostNativeThreadBase.{h,cpp}, which break builds
on Windows.
Identified with modernize-use-nullptr.
This reverts commit 913457acf0.
It again broke builds on Windows:
lldb/source/Host/common/HostNativeThreadBase.cpp(37,14): error:
assigning to 'lldb::thread_result_t' (aka 'unsigned int') from
incompatible type 'std::nullptr_t'
This is a re-submission of 24d2405588
without the hunk in HostNativeThreadBase.h, which breaks builds on
Windows.
Identified with modernize-use-nullptr.
This reverts commit 24d2405588.
Breaks building on Windows:
../../lldb/include\lldb/Host/HostNativeThreadBase.h(49,36): error:
cannot initialize a member subobject of type 'lldb::thread_result_t'
(aka 'unsigned int') with an rvalue of type 'std::nullptr_t'
lldb::thread_result_t m_result = nullptr;
^~~~~~~
1 error generated.
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.
Support three new keys in the qProcessInfo response from the remote
gdb stub to handle the case of attaching to a core running some type
of standalone/firmware code and the stub knows the UUID and load
address-or-slide for the binary. There will be no proper DynamicLoader
plugin in this scenario, but we can try to locate and load the binary
into lldb at the correct offset.
Differential Revision: https://reviews.llvm.org/D116211
rdar://75191077
Introduce initial support for using libkvm on FreeBSD. The library
can be used as an alternate implementation for processing kernel
coredumps but it can also be used to access live kernel memory through
specifying "/dev/mem" as the core file, i.e.:
lldb --core /dev/mem /boot/kernel/kernel
Differential Revision: https://reviews.llvm.org/D116005
Version 2 of 'main bin spec' LC_NOTE allows for the specification
of a slide of where the binary is loaded in the corefile virtual
address space. It also adds a (currently unused) platform field
for the main binary.
Some corefile creators will only have a UUID and an offset to be
applied to the binary.
Changed TestFirmwareCorefiles.py to test this new form of
'main bin spec' with a slide, and also to run on both x86_64
and arm64 macOS systems.
Differential Revision: https://reviews.llvm.org/D116094
rdar://85938455
Introduce a FreeBSDKernel plugin that provides the ability to read
FreeBSD kernel core dumps. The plugin utilizes libfbsdvmcore to provide
support for both "full memory dump" and minidump formats across variety
of architectures supported by FreeBSD. It provides the ability to read
kernel memory, as well as the crashed thread status with registers
on arm64, i386 and x86_64.
Differential Revision: https://reviews.llvm.org/D114911
Introduce a FreeBSDKernel plugin that provides the ability to read
FreeBSD kernel core dumps. The plugin utilizes libfbsdvmcore to provide
support for both "full memory dump" and minidump formats across variety
of architectures supported by FreeBSD. It provides the ability to read
kernel memory, as well as the crashed thread status with registers
on arm64, i386 and x86_64.
Differential Revision: https://reviews.llvm.org/D114911
This patch adds support for arm64(e) targets to ScriptedProcess, by
providing the `DynamicRegisterInfo` to the base `lldb.ScriptedThread` class.
This allows create and debugging ScriptedProcess on Apple Silicon
hardware as well as Apple mobile devices.
It also replace the C++ asserts on `ScriptedThread::GetDynamicRegisterInfo`
by some error logging, re-enables `TestScriptedProcess` for arm64
Darwin platforms and adds a new invalid Scripted Thread test.
rdar://85892451
Differential Revision: https://reviews.llvm.org/D114923
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
Recognize FreeBSD vmcores (kernel core dumps) through OS ABI = 0xFF
+ ELF version = 0, and do not process them via the elf-core plugin.
While these files use ELF as a container format, they contain raw memory
dump rather than proper VM segments and therefore are not usable
to the elf-core plugin.
Differential Revision: https://reviews.llvm.org/D114967
Symbol table parsing has evolved over the years and many plug-ins contained duplicate code in the ObjectFile::GetSymtab() that used to be pure virtual. With this change, the "Symbtab *ObjectFile::GetSymtab()" is no longer virtual and will end up calling a new "void ObjectFile::ParseSymtab(Symtab &symtab)" pure virtual function to actually do the parsing. This helps centralize the code for parsing the symbol table and allows the ObjectFile base class to do all of the common work, like taking the necessary locks and creating the symbol table object itself. Plug-ins now just need to parse when they are asked to parse as the ParseSymtab function will only get called once.
This is a retry of the original patch https://reviews.llvm.org/D113965 which was reverted. There was a deadlock in the Manual DWARF indexing code during symbol preloading where the module was asked on the main thread to preload its symbols, and this would in turn cause the DWARF manual indexing to use a thread pool to index all of the compile units, and if there were relocations on the debug information sections, these threads could ask the ObjectFile to load section contents, which could cause a call to ObjectFileELF::RelocateSection() which would ask for the symbol table from the module and it would deadlock. We can't lock the module in ObjectFile::GetSymtab(), so the solution I am using is to use a llvm::once_flag to create the symbol table object once and then lock the Symtab object. Since all APIs on the symbol table use this lock, this will prevent anyone from using the symbol table before it is parsed and finalized and will avoid the deadlock I mentioned. ObjectFileELF::GetSymtab() was never locking the module lock before and would put off creating the symbol table until somewhere inside ObjectFileELF::GetSymtab(). Now we create it one time inside of the ObjectFile::GetSymtab() and immediately lock it which should be safe enough. This avoids the deadlocks and still provides safety.
Differential Revision: https://reviews.llvm.org/D114288
This reverts commit fac3f20de5.
I found this has broken how we detect the last memory region in
GetMemoryRegions/"memory region" command.
When you're debugging an AArch64 system with pointer authentication,
the ABI plugin will remove the top bit from the end address of the last
user mapped area.
(lldb)
[0x0000fffffffdf000-0x0001000000000000) rw- [stack]
ABI plugin removes anything above the 48th bit (48 bit virtual addresses
by default on AArch64, leaving an address of 0.
(lldb)
[0x0000000000000000-0x0000000000400000) ---
You get back a mapping for 0 and get into an infinite loop.
Although I cannot find any mention of this in the specification, both
gdb and lldb agree on sending an initial + packet after establishing the
connection.
OTOH, gdbserver and lldb-server behavior is subtly different. While
lldb-server *expects* the initial ack, and drops the connection if it is
not received, gdbserver will just ignore a spurious ack at _any_ point
in the connection.
This patch changes lldb's behavior to match that of gdb. An ACK packet
is ignored at any point in the connection (except when expecting an ACK
packet, of course). This is inline with the "be strict in what you
generate, and lenient in what you accept" philosophy, and also enables
us to remove some special cases from the server code. I've extended the
same handling to NAK (-) packets, mainly because I don't see a reason to
treat them differently here.
(The background here is that we had a stub which was sending spurious
+ packets. This bug has since been fixed, but I think this change makes
sense nonetheless.)
Differential Revision: https://reviews.llvm.org/D114520
This code, added in rL197579 (Dec 2013) is supposed to work around what
was presumably a qemu bug, where it would send unsolicited stop-reply
packets after the initial connection.
At present, qemu does not exhibit such behavior. Also, the 10ms delay
introduced by this code is sufficient to mask bugs in other stubs, but
it is not sufficient to *reliably* mask those bugs. This resulted in
flakyness in one of our stubs, which was (incorrectly) sending a +
packet at the start of the connection, resulting in a small-but-annoying
number of dropped connections.
Differential Revision: https://reviews.llvm.org/D114529
This reverts commit 951b107eed.
Buildbots were failing, there is a deadlock in /Users/gclayton/Documents/src/llvm/clean/llvm-project/lldb/test/Shell/SymbolFile/DWARF/DW_AT_range-DW_FORM_sec_offset.s when ELF files try to relocate things.
Symbol table parsing has evolved over the years and many plug-ins contained duplicate code in the ObjectFile::GetSymtab() that used to be pure virtual. With this change, the "Symbtab *ObjectFile::GetSymtab()" is no longer virtual and will end up calling a new "void ObjectFile::ParseSymtab(Symtab &symtab)" pure virtual function to actually do the parsing. This helps centralize the code for parsing the symbol table and allows the ObjectFile base class to do all of the common work, like taking the necessary locks and creating the symbol table object itself. Plug-ins now just need to parse when they are asked to parse as the ParseSymtab function will only get called once.
Differential Revision: https://reviews.llvm.org/D113965
The reworking of the gdb client tests into the PlatformClientTestBase broke
the test for this. I did the mutatis mutandis for the move, but the test
still fails. Reverting till I have time to figure out why.
This reverts commit b715b79d54.
We don't actually need a local copy of the main executable to debug
a remote process. So instead of treating "no local module" as an error,
see if the LaunchInfo has an executable it wants lldb to use, and if so
use it. Then report whatever error the remote server returns.
Differential Revision: https://reviews.llvm.org/D113521
[NFC] This patch replaces master and slave with primary and secondary
respectively when referring to pseudoterminals/file descriptors.
Reviewed By: clayborg, teemperor
Differential Revision: https://reviews.llvm.org/D113687
This patch changes the ScriptedThread class to create the register
context when Process::RefreshStateAfterStop is called rather than
doing it in the thread constructor.
This is required to update the thread state for execution control.
Differential Revision: https://reviews.llvm.org/D112167
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
This patch adds a new `StructuredData::Dictionary` constructor that
takes a `StructuredData::ObjectSP` as an argument. This is used to pass
the opaque_ptr from the `SBStructuredData` used to initialize a
ScriptedProecss, to the `ProcessLaunchInfo` class.
This also updates `SBLaunchInfo::SetScriptedProcessDictionary` to
reflect the formentionned changes which solves the nullptr deref.
Differential Revision: https://reviews.llvm.org/D112107
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
Fix the fill_clamp() function to handle signed source types. Make sure
that the source value is always non-negative, and cast it to unsigned
when verifying the upper bound. This fixes compiler warnings about
comparing unsigned and signed types.
Differential Revision: https://reviews.llvm.org/D113519
GDB and LLDB use different signal models. GDB uses a predefined set
of signal codes, and maps platform's signos to them. On the other hand,
LLDB has historically simply passed native signos.
In order to improve compatibility between LLDB and gdbserver, the GDB
signal model should be used. However, GDB does not provide a mapping
for all existing signals on Linux and unsupported signals are passed
as 'unknown'. Limiting LLDB to this behavior could be considered
a regression.
To get the best of both worlds, use the LLDB signal model when talking
to lldb-server, and the GDB signal model otherwise. For this purpose,
new versions of lldb-server indicate "native-signals+" via qSupported.
At the same time, we also detect older versions of lldb-server
via QThreadSuffixSupported for backwards compatibility. If neither test
succeeds, we assume gdbserver or another implementation using GDB model.
Differential Revision: https://reviews.llvm.org/D108078
From the documentation:
A Twine is not intended for use directly and should not be stored, its
implementation relies on the ability to store pointers to temporary
stack objects which may be deallocated at the end of a statement.
Twines should only be used accepted as const references in arguments,
when an API wishes to accept possibly-concatenated strings.
rdar://84799118
Differential revision: https://reviews.llvm.org/D113314
This reverts commit 5fbcf67734.
ProcessDebugger is used in ProcessWindows and NativeProcessWindows.
I thought I was simplifying things by renaming to DoGetMemoryRegionInfo
in ProcessDebugger but the Native process side expects "GetMemoryRegionInfo".
Follow the pattern that WriteMemory uses. So:
* ProcessWindows::DoGetMemoryRegioninfo calls ProcessDebugger::GetMemoryRegionInfo
* NativeProcessWindows::GetMemoryRegionInfo does the same
On AArch64 we have various things using the non address bits
of pointers. This means when you lookup their containing region
you won't find it if you don't remove them.
This changes Process GetMemoryRegionInfo to a non virtual method
that uses the current ABI plugin to remove those bits. Then it
calls DoGetMemoryRegionInfo.
That function does the actual work and is virtual to be overriden
by Process implementations.
A test case is added that runs on AArch64 Linux using the top
byte ignore feature.
Reviewed By: omjavaid
Differential Revision: https://reviews.llvm.org/D102757
Fix regression in processing generic regnums that was introduced
in fa456505b8 ("[lldb] [gdb-remote]
Refactor getting remote regs to use local vector"). Since then,
the "generic" field was wrongly interpreted as integer rather than
string constant.
Thanks to Ted Woodward for noticing and providing the correct code.
Remove the port predicate from Socket and ConnectionFileDescriptor,
and move it to gdb-remote. It is specifically relevant to the threading
used inside gdb-remote and with the new port callback API, we can
reliably move it there. While at it, switch from the custom Predicate
to std::promise/std::future.
Differential Revision: https://reviews.llvm.org/D112357
Unify the listen and connect code inside lldb-server to use
ConnectionFileDescriptor uniformly rather than a mix of it and Acceptor.
This involves:
- adding a function to map legacy values of host:port parameter
(including legacy server URLs) into CFD-style URLs
- adding a callback to return "local socket id" (i.e. UNIX socket path
or TCP port number) between listen() and accept() calls in CFD
- adding a "unix-abstract-accept" scheme to CFD
As an additional advantage, this permits lldb-server to accept any URL
known to CFD including the new serial:// scheme. Effectively,
lldb-server can now listen on the serial port. Tests for connecting
over a pty are added to test that.
Differential Revision: https://reviews.llvm.org/D111964
Add a Communication::WriteAll() that resumes Write() if the initial call
did not write all data. Use it in GDBRemoteCommunication when sending
packets in order to fix handling partial writes (i.e. just resume/retry
them rather than erring out). This fixes LLDB failures when writing
large packets to a pty.
Differential Revision: https://reviews.llvm.org/D112169
Replace bool+by-ref argument with llvm::Optional, and move the common
implementation into HostInfoPOSIX. Based on my (simple) experiment,
the uname and the sysctl approach return the same value on MacOS, so
there's no need for a mac-specific implementation of this functionality.
Differential Revision: https://reviews.llvm.org/D112457
HardcodeARMRegisters() is a hack that was supposed to be used "until
we can get an updated debugserver down on the devices". Since it was
introduced back in 2012, there is a good chance that the debugserver
has been updated at least once since then. Removing this code makes
transition to the new DynamicRegisterInfo API easier.
Differential Revision: https://reviews.llvm.org/D111491
