The type field is a signed integer.
(https://sourceware.org/gdb/current/onlinedocs/gdb/General-Query-Packets.html)
However it's not packed in the packet in the way
you might think. For example the type -1 should be:
qMemTags:<addr>,<len>:ffffffff
Instead of:
qMemTags:<addr>,<len>:-1
This change makes lldb-server's parsing more strict
and adds more tests to check that we handle negative types
correctly in lldb and lldb-server.
We only support one tag type value at this point,
for AArch64 MTE, which is positive. So this doesn't change
any of those interactions. It just brings us in line with GDB.
Also check that the test target has MTE. Previously
we just checked that we were AArch64 with a toolchain
that supports MTE.
Finally, update the tag type check for QMemTags to use
the same conversion steps that qMemTags now does.
Using static_cast can invoke UB and though we do do a limit
check to avoid this, I think it's clearer with the new method.
Reviewed By: omjavaid
Differential Revision: https://reviews.llvm.org/D104914
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
Support using the extended thread-id syntax with Hg packet to select
a subprocess. This makes it possible to start providing support for
running some of the debugger packets against another subprocesses.
Differential Revision: https://reviews.llvm.org/D100261
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
Add a NativeDelegate API to pass new processes (forks) to LLGS,
and support detaching them via the 'D' packet. A 'D' packet without
a specific PID detaches all processes, otherwise it detaches either
the specified subprocess or the main process, depending on the passed
PID.
Differential Revision: https://reviews.llvm.org/D100191
Introduce three new stop reasons for fork, vfork and vforkdone events.
This includes server support for serializing fork/vfork events into
gdb-remote protocol. The stop infos for the two base events take a pair
of PID and TID for the newly forked process.
Differential Revision: https://reviews.llvm.org/D100196
Introduce a NativeProcessProtocol API for indicating support for
protocol extensions and enabling them. LLGS calls
GetSupportedExtensions() method on the process factory to determine
which extensions are supported by the plugin. If the future is both
supported by the plugin and reported as supported by the client, LLGS
enables it and reports to the client as supported by the server.
The extension is enabled on the process instance by calling
SetEnabledExtensions() method. This is done after qSupported exchange
(if the debugger is attached to any process), as well as after launching
or attaching to a new inferior.
The patch adds 'fork' extension corresponding to 'fork-events+'
qSupported feature and 'vfork' extension for 'vfork-events+'. Both
features rely on 'multiprocess+' being supported as well.
Differential Revision: https://reviews.llvm.org/D100153
These were in the shared llgs+platform code, but they only make sense
for llgs (as they deal with how the server reports information about
debugged processes).
Introduce new m_current_process and m_continue_process variables that
keep the pointers to currently selected process. At this moment, this
is equivalent to m_debugged_process_up but it lays foundations for
the future multiprocess support.
Differential Revision: https://reviews.llvm.org/D100256
Refactor handling qSupported to use a virtual HandleFeatures() method.
The client-provided features are split into an array and passed
to the method. The method returns an array of server features that are
concatenated into the qSupported response to the server.
The base implementation of HandleFeatures()
in GDBRemoteCommunicationServerCommon now includes only flags common
to both platform server and llgs, while llgs-specific flags are inserted
in GDBRemoteCommunicationServerLLGS.
Differential Revision: https://reviews.llvm.org/D100140
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
Add a minimal support for the multiprocess extension in lldb-server.
The server indicates support for it via qSupported, and accepts
thread-ids containing a PID. However, it still does not support
debugging more than one inferior, so any other PID value results
in an error.
Differential Revision: https://reviews.llvm.org/D98482
Implements the required functions on gdb-remote so the '--include-existing' flag of process attach works correctly on Linux.
Reviewed By: labath, clayborg
Differential Revision: https://reviews.llvm.org/D94672
This commit vAttachWait in lldb-server, so --waitfor can be used on
Linux
Reviewed By: labath, clayborg
Differential Revision: https://reviews.llvm.org/D93895
This patch carries forward our aim to remove offset field from qRegisterInfo
packets and XML register description. I have created a new function which
returns if offset fields are dynamic meaning client can calculate offset on
its own based on register number sequence and register size. For now this
function only returns true for NativeRegisterContextLinux_arm64 but we can
test this for other architectures and make it standard later.
As a consequence we do not send offset field from lldb-server (arm64 for now)
while other stubs dont have an offset field so it wont effect them for now.
On the client side we have replaced previous offset calculation algorithm
with a new scheme, where we sort all primary registers in increasing
order of remote regnum and then calculate offset incrementally.
This committ also includes a test to verify all of above functionality
on Arm64.
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D91241
This patch adds capability to introduce a custom expedited register set
in gdb remote. Currently we send register set 0 as expedited register set
but for the case of AArch64 SVE we intend to send additional information
about SVE registers size/offset configuration which can be calculated
from vg register. Therefore we will expedited Vg register in case of
AArch64 is in SVE mode to speedup register configuration calculations.
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D82853
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
Fix two bugs that caused attaching to a process in a pre-connected
lldb-server to fail. These are:
1. Prematurely reporting status in NativeProcessFreeBSD::Attach().
The SetState() call defaulted to notify the process, and LLGS tried
to send the stopped packet before the process instance was assigned
to it. While at it, add an assert for that in LLGS.
2. Duplicate call to ReinitializeThreads() (via SetupTrace()) that
overwrote the stopped status in threads. Now SetupTrace() is called
directly by NativeProcessFreeBSD::Attach() (not the Factory) in place
of ReinitializeThreads().
This fixes at least commands/process/attach/TestProcessAttach.py
and python_api/hello_world/TestHelloWorld.py.
Differential Revision: https://reviews.llvm.org/D90525
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
This is essentially a replacement for the PacketUnimplementedError
previously present in the gdb-remote server code.
The reason I am introducing a generic error is because I wanted the
native process classes to be able to signal that they do not support
some functionality. They could not use PacketUnimplementedError as they
are independent of a specific transport protocol. Putting the error
class in the the native process code was also not ideal because the
gdb-remote code is also used for lldb-server's platform mode, which does
not (should not) know how to debug individual processes.
I'm putting it under Utility, as I think it can be generally useful for
notifying about unsupported/unimplemented functionality (and in
particular, for programatically testing whether something is
unsupported).
Differential Revision: https://reviews.llvm.org/D89121
Summary: This patch increases maximum register size to 256 bytes to accommodate AArch64 SVE registers maximum possible size of 256 bytes.
Reviewers: labath, jankratochvil, rengolin
Reviewed By: labath
Subscribers: tschuett, kristof.beyls, danielkiss, lldb-commits
Differential Revision: https://reviews.llvm.org/D77044
This patch adds parts of the stack that should be useful for unwinding
to the jThreadsInfo reply from lldb-server. We return the top of the
stack (12 words), and we also try to walk the frame pointer linked list
and return the memory containing frame pointer and return address pairs.
The idea is to cover the cases with and without frame pointer omission.
Differential Revision: https://reviews.llvm.org/D74398
Summary:
Requesting registers one by one takes a while in our project.
We want to get rid of it by using target.xml.
Reviewers: jarin, labath, omjavaid
Reviewed By: labath, omjavaid
Subscribers: omjavaid, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D74217
Summary:
Synthesize target.xml in lldb-server to avoid a long chain of
qRegisterInfo packets, which can be slow over low-latency links.
Reviewers: jarin, labath
Reviewed By: labath
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D74217
StringRef will call strlen on the C string which is inefficient (as ConstString already
knows the string lenght and so does StringRef). This patch replaces all those calls
with GetStringRef() which doesn't recompute the length.
Due to a c++ quirk, these are found through ADL only when a function with that
name is found through regular lookup. We have one such function in SharingPtr.h,
but I am trying to remove it.
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
Summary: There are a few places in LLDB where we do a `reinterpret_cast` for conversions that we could also do with `static_cast`. This patch moves all this code to `static_cast`.
Reviewers: shafik, JDevlieghere, labath
Reviewed By: labath
Subscribers: arphaman, usaxena95, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D72161
There's no need to wrap the just-constructed json::Array in a
json::Value, we can just return that and pass ownership to the
raw_ostream.
llvm-svn: 373656
Although it's called "GetString", StreamString::GetString actually
returns a StringRef. Creating a json object with a StringRef does not
make a copy, which means the StringRef will be dangling as soon as the
underlying stream is destroyed. Add a .str() to force the json object to
hold a copy of the string.
This fixes nearly every test on linux.
llvm-svn: 373572
This patch replaces the LLDB's JSON implementation with the one from
LLVM in GDBRemoteCommunicationServerLLGS.
Differential revision: https://reviews.llvm.org/D68299
llvm-svn: 373497
Fix processing of "C" packet with signal for the whole process to
default signal value for action list to LLDB_INVALID_SIGNAL_NUMBER
rather than 0.
Differential Revision: https://reviews.llvm.org/D67625
llvm-svn: 372090
To support dumping the reproducer's GDB remote packets, we need the
(de)serialization logic to live in Utility rather than the GDB remote
plugin. This patch renames StreamGDBRemote to GDBRemote and moves the
relevant packet code there.
Its uses in the GDBRemoteCommunicationHistory and the
GDBRemoteCommunicationReplayServer are updated as well.
Differential revision: https://reviews.llvm.org/D67523
llvm-svn: 371907
This patch removes the two variant of StringExtractor::GetStringRef that
return (non-)const references to std::string. The non-const one was
being abused to reinitialize the StringExtractor and its uses are
replaced by calls to the copy asignment operator. The const variant was
refactored to return an actual llvm::StringRef.
llvm-svn: 369493
Summary:
This commit contains three small changes to enable lldb-server on Windows.
- Add lldb-server for Windows to the build
- Disable pty redirection on Windows for the initial lldb-server bring up
- Add a support to get the parent pid for a process on Windows
- Ifdef some signals which aren't supported on Windows
Thanks to Hui Huang for the help with this patch!
Reviewers: labath
Reviewed By: labath
Subscribers: JDevlieghere, compnerd, Hui, amccarth, xiaobai, srhines, mgorny, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D61686
llvm-svn: 368774
This patch replaces explicit calls to log::Printf with the new LLDB_LOGF
macro. The macro is similar to LLDB_LOG but supports printf-style format
strings, instead of formatv-style format strings.
So instead of writing:
if (log)
log->Printf("%s\n", str);
You'd write:
LLDB_LOG(log, "%s\n", str);
This change was done mechanically with the command below. I replaced the
spurious if-checks with vim, since I know how to do multi-line
replacements with it.
find . -type f -name '*.cpp' -exec \
sed -i '' -E 's/log->Printf\(/LLDB_LOGF\(log, /g' "{}" +
Differential revision: https://reviews.llvm.org/D65128
llvm-svn: 366936
David Spickett