Extend support in LLDB for WebAssembly. This PR adds a new Process
plugin (ProcessWasm) that extends ProcessGDBRemote for WebAssembly
targets. It adds support for WebAssembly's memory model with separate
address spaces, and the ability to fetch the call stack from the
WebAssembly runtime.
I have tested this change with the WebAssembly Micro Runtime (WAMR,
https://github.com/bytecodealliance/wasm-micro-runtime) which implements
a GDB debug stub and supports the qWasmCallStack packet.
```
(lldb) process connect --plugin wasm connect://localhost:4567
Process 1 stopped
* thread #1, name = 'nobody', stop reason = trace
frame #0: 0x40000000000001ad
wasm32_args.wasm`main:
-> 0x40000000000001ad <+3>: global.get 0
0x40000000000001b3 <+9>: i32.const 16
0x40000000000001b5 <+11>: i32.sub
0x40000000000001b6 <+12>: local.set 0
(lldb) b add
Breakpoint 1: where = wasm32_args.wasm`add + 28 at test.c:4:12, address = 0x400000000000019c
(lldb) c
Process 1 resuming
Process 1 stopped
* thread #1, name = 'nobody', stop reason = breakpoint 1.1
frame #0: 0x400000000000019c wasm32_args.wasm`add(a=<unavailable>, b=<unavailable>) at test.c:4:12
1 int
2 add(int a, int b)
3 {
-> 4 return a + b;
5 }
6
7 int
(lldb) bt
* thread #1, name = 'nobody', stop reason = breakpoint 1.1
* frame #0: 0x400000000000019c wasm32_args.wasm`add(a=<unavailable>, b=<unavailable>) at test.c:4:12
frame #1: 0x40000000000001e5 wasm32_args.wasm`main at test.c:12:12
frame #2: 0x40000000000001fe wasm32_args.wasm
```
This PR is based on an unmerged patch from Paolo Severini:
https://reviews.llvm.org/D78801. I intentionally stuck to the
foundations to keep this PR small. I have more PRs in the pipeline to
support the other features/packets.
My motivation for supporting Wasm is to support debugging Swift compiled
to WebAssembly:
https://www.swift.org/documentation/articles/wasm-getting-started.html
This reapplies commit
232525f069.
The original commit triggered a sanitizer failure when `Target` was
destroyed. In `Target::Destroy`, `DeleteCurrentProcess` was called, but
it did not destroy the thread creation breakpoints for the underlying
`ProcessGDBRemote` because `ProcessGDBRemote::Clear` was not called in
that path.
`Target `then proceeded to destroy its breakpoints, which resulted in a
call to the destructor of a `std::vector` containing the breakpoints.
Through a sequence of complicated events, destroying breakpoints caused
the reference count of the underlying `ProcessGDBRemote` to finally
reach zero. This, in turn, called `ProcessGDBRemote::Clear`, which
attempted to destroy the breakpoints. To do that, it would go back into
the Target's vector of breakpoints, which we are in the middle of
destroying.
We solve this by moving the breakpoint deletion into
`Process:DoDestroy`, which is a virtual Process method that will be
called much earlier.
This reverts commit
87b7f63a11,
reapplying
7e66cf74fb
with a small (and probably temporary)
change to generate more debug info to help with diagnosing buildbot
issues.
This reverts commit a774de807e56c1147d4630bfec3110c11d41776e.
This is the same changes as last time, plus:
* We load the binary into the target object so that on Windows, we can
resolve the locations of the functions.
* We now assert that each required breakpoint has at least 1 location,
to prevent an issue like that in the future.
* We are less strict about the unsupported error message, because it
prints "error: windows" on Windows instead of "error: gdb-remote".
Reverts llvm/llvm-project#123945
Has failed on the Windows on Arm buildbot:
https://lab.llvm.org/buildbot/#/builders/141/builds/5865
```
********************
Unresolved Tests (2):
lldb-api :: functionalities/reverse-execution/TestReverseContinueBreakpoints.py
lldb-api :: functionalities/reverse-execution/TestReverseContinueWatchpoints.py
********************
Failed Tests (1):
lldb-api :: functionalities/reverse-execution/TestReverseContinueNotSupported.py
```
Reverting while I reproduce locally.
This reverts commit 22561cfb443267905d4190f0e2a738e6b412457f and fixes
b7b9ccf44988edf49886743ae5c3cf4184db211f (#112079).
The problem is that x86_64 and Arm 32-bit have memory regions above the
stack that are readable but not writeable. First Arm:
```
(lldb) memory region --all
<...>
[0x00000000fffcf000-0x00000000ffff0000) rw- [stack]
[0x00000000ffff0000-0x00000000ffff1000) r-x [vectors]
[0x00000000ffff1000-0xffffffffffffffff) ---
```
Then x86_64:
```
$ cat /proc/self/maps
<...>
7ffdcd148000-7ffdcd16a000 rw-p 00000000 00:00 0 [stack]
7ffdcd193000-7ffdcd196000 r--p 00000000 00:00 0 [vvar]
7ffdcd196000-7ffdcd197000 r-xp 00000000 00:00 0 [vdso]
ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0 [vsyscall]
```
Compare this to AArch64 where the test did pass:
```
$ cat /proc/self/maps
<...>
ffffb87dc000-ffffb87dd000 r--p 00000000 00:00 0 [vvar]
ffffb87dd000-ffffb87de000 r-xp 00000000 00:00 0 [vdso]
ffffb87de000-ffffb87e0000 r--p 0002a000 00:3c 76927217 /usr/lib/aarch64-linux-gnu/ld-linux-aarch64.so.1
ffffb87e0000-ffffb87e2000 rw-p 0002c000 00:3c 76927217 /usr/lib/aarch64-linux-gnu/ld-linux-aarch64.so.1
fffff4216000-fffff4237000 rw-p 00000000 00:00 0 [stack]
```
To solve this, look up the memory region of the stack pointer (using
https://lldb.llvm.org/resources/lldbgdbremote.html#qmemoryregioninfo-addr)
and constrain the read to within that region. Since we know the stack is
all readable and writeable.
I have also added skipIfRemote to the tests, since getting them working
in that context is too complex to be worth it.
Memory write failures now display the range they tried to write, and
register write errors will show the name of the register where possible.
The patch also includes a workaround for a an issue where the test code
could mistake an `x` response that happens to begin with an `O` for an
output packet (stdout). This workaround will not be necessary one we
start using the [new
implementation](https://discourse.llvm.org/t/rfc-fixing-incompatibilties-of-the-x-packet-w-r-t-gdb/84288)
of the `x` packet.
---------
Co-authored-by: Pavel Labath <pavel@labath.sk>
This commit adds support for a
`SBProcess::ContinueInDirection()` API. A user-accessible command for
this will follow in a later commit.
This feature depends on a gdbserver implementation (e.g. `rr`) providing
support for the `bc` and `bs` packets. `lldb-server` does not support
those packets, and there is no plan to change that. For testing
purposes, this commit adds a Python implementation of *very limited*
record-and-reverse-execute functionality, implemented as a proxy between
lldb and lldb-server in `lldbreverse.py`. This should not (and in
practice cannot) be used for anything except testing.
The tests here are quite minimal but we test that simple breakpoints and
watchpoints work as expected during reverse execution, and that
conditional breakpoints and watchpoints work when the condition calls a
function that must be executed in the forward direction.
Reverting this again; I added a commit which added @skipIfDarwin
markers to the TestReverseContinueBreakpoints.py and
TestReverseContinueNotSupported.py API tests, which use lldb-server
in gdbserver mode which does not work on Darwin. But the aarch64 ubuntu
bot reported a failure on TestReverseContinueBreakpoints.py,
https://lab.llvm.org/buildbot/#/builders/59/builds/6397
File "/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/llvm-project/lldb/test/API/functionalities/reverse-execution/TestReverseContinueBreakpoints.py", line 63, in test_reverse_continue_skip_breakpoint
self.reverse_continue_skip_breakpoint_internal(async_mode=False)
File "/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/llvm-project/lldb/test/API/functionalities/reverse-execution/TestReverseContinueBreakpoints.py", line 81, in reverse_continue_skip_breakpoint_internal
self.expect(
File "/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/llvm-project/lldb/packages/Python/lldbsuite/test/lldbtest.py", line 2372, in expect
self.runCmd(
File "/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/llvm-project/lldb/packages/Python/lldbsuite/test/lldbtest.py", line 1002, in runCmd
self.assertTrue(self.res.Succeeded(), msg + output)
AssertionError: False is not true : Process should be stopped due to history boundary
Error output:
error: Process must be launched.
This reverts commit 4f297566b3150097de26c6a23a987d2bd5fc19c5.
This commit only adds support for the
`SBProcess::ReverseContinue()` API. A user-accessible command for this
will follow in a later commit.
This feature depends on a gdbserver implementation (e.g. `rr`) providing
support for the `bc` and `bs` packets. `lldb-server` does not support
those packets, and there is no plan to change that. So, for testing
purposes, `lldbreverse.py` wraps `lldb-server` with a Python
implementation of *very limited* record-and-replay functionality for use
by *tests only*.
The majority of this PR is test infrastructure (about 700 of the 950
lines added).
This commit only adds support for the
`SBProcess::ReverseContinue()` API. A user-accessible command for this
will follow in a later commit.
This feature depends on a gdbserver implementation (e.g. `rr`) providing
support for the `bc` and `bs` packets. `lldb-server` does not support
those packets, and there is no plan to change that. So, for testing
purposes, `lldbreverse.py` wraps `lldb-server` with a Python
implementation of *very limited* record-and-replay functionality for use
by *tests only*.
The majority of this PR is test infrastructure (about 700 of the 950
lines added).
This PR introduces a new `ThreadPlanSingleThreadTimeout` that will be
used to address potential deadlock during single-thread stepping.
While debugging a target with a non-trivial number of threads (around
5000 threads in one example target), we noticed that a simple step over
can take as long as 10 seconds. Enabling single-thread stepping mode
significantly reduces the stepping time to around 3 seconds. However,
this can introduce deadlock if we try to step over a method that depends
on other threads to release a lock.
To address this issue, we introduce a new
`ThreadPlanSingleThreadTimeout` that can be controlled by the
`target.process.thread.single-thread-plan-timeout` setting during
single-thread stepping mode. The concept involves counting the elapsed
time since the last internal stop to detect overall stepping progress.
Once a timeout occurs, we assume the target is not making progress due
to a potential deadlock, as mentioned above. We then send a new async
interrupt, resume all threads, and `ThreadPlanSingleThreadTimeout`
completes its task.
To support this design, the major changes made in this PR are:
1. `ThreadPlanSingleThreadTimeout` is popped during every internal stop
and reset (re-pushed) to the top of the stack (as a leaf node) during
resume. This is achieved by always returning `true` from
`ThreadPlanSingleThreadTimeout::DoPlanExplainsStop()` and
`ThreadPlanSingleThreadTimeout::MischiefManaged()`.
2. A new thread-specific async interrupt stop is introduced, which can
be detected/consumed by `ThreadPlanSingleThreadTimeout`.
3. The clearing of branch breakpoints in the range thread plan has been
moved from `DoPlanExplainsStop()` to `ShouldStop()`, as it is not
guaranteed that it will be called.
The detailed design is discussed in the RFC below:
[https://discourse.llvm.org/t/improve-single-thread-stepping/74599](https://discourse.llvm.org/t/improve-single-thread-stepping/74599)
---------
Co-authored-by: jeffreytan81 <jeffreytan@fb.com>
This reverts commit d9e659c538516036e40330b6a98160cbda4ff100.
I could not reproduce the Mac OS ASAN failure locally but I narrowed it
down to the test `test_many_fields_same_enum`. This test shares an enum
between x0, which is 64 bit, and cpsr, which is 32 bit.
My theory is that when it does `register read x0`, an enum type is
created where the undlerying enumerators are 64 bit, matching the
register size.
Then it does `register read cpsr` which used the cached enum type, but
this register is 32 bit. This caused lldb to try to read an 8 byte value
out of a 4 byte allocation:
READ of size 8 at 0x60200014b874 thread T0
<...>
=>0x60200014b800: fa fa fd fa fa fa fd fa fa fa fd fa fa fa[04]fa
To fix this I've added the register's size in bytes to the constructed
enum type's name. This means that x0 uses:
__lldb_register_fields_enum_some_enum_8
And cpsr uses:
__lldb_register_fields_enum_some_enum_4
If any other registers use this enum and are read, they will use the
cached type as long as their size matches, otherwise we make a new type.
This teaches lldb to parse the enum XML elements sent by lldb-server,
and make use of the information in `register read` and `register info`.
The format is described in
https://sourceware.org/gdb/current/onlinedocs/gdb.html/Enum-Target-Types.html.
The target XML parser will drop any invalid enum or evalue. If we find
multiple evalue for the same value, we will use the last one we find.
The order of evalues from the XML is preserved as there may be good
reason they are not in numerical order.
We got user reporting lldb crash while the debuggee is calling vfork()
concurrently from multiple threads.
The crash happens because the current implementation can only handle
single vfork, vforkdone protocol transaction.
This diff fixes the crash by lldb-server storing forked debuggee's <pid,
tid> pair in jstopinfo which will be decoded by lldb client to create
StopInfoVFork for follow parent/child policy. Each StopInfoVFork will
later have a corresponding vforkdone packet. So the patch also changes
the `m_vfork_in_progress` to be reference counting based.
Two new test cases are added which crash/assert without the changes in
this patch.
---------
Co-authored-by: jeffreytan81 <jeffreytan@fb.com>
This patch is rearranging code a bit to add WatchpointResources to
Process. A WatchpointResource is meant to represent a hardware
watchpoint register in the inferior process. It has an address, a size,
a type, and a list of Watchpoints that are using this
WatchpointResource.
This current patch doesn't add any of the features of
WatchpointResources that make them interesting -- a user asking to watch
a 24 byte object could watch this with three 8 byte WatchpointResources.
Or a Watchpoint on 1 byte at 0x1002 and a second watchpoint on 1 byte at
0x1003, these must both be served by a single WatchpointResource on that
doubleword at 0x1000 on a 64-bit target, if two hardware watchpoint
registers were used to track these separately, one of them may not be
hit. Or if you have one Watchpoint on a variable with a condition set,
and another Watchpoint on that same variable with a command defined or
different condition, or ignorecount, both of those Watchpoints need to
evaluate their criteria/commands when their WatchpointResource has been
hit.
There's a bit of code movement to rearrange things in the direction I'll
need for implementing this feature, so I want to start with reviewing &
landing this mostly NFC patch and we can focus on the algorithmic
choices about how WatchpointResources are shared and handled as they're
triggeed, separately.
This patch also stops printing "Watchpoint <n> hit: old value: <x>, new
vlaue: <y>" for Read watchpoints. I could make an argument for print
"Watchpoint <n> hit: current value <x>" but the current output doesn't
make any sense, and the user can print the value if they are
particularly interested. Read watchpoints are used primarily to
understand what code is reading a variable.
This patch adds more fallbacks for how to print the objects being
watched if we have types, instead of assuming they are all integral
values, so a struct will print its elements. As large watchpoints are
added, we'll be doing a lot more of those.
To track the WatchpointSP in the WatchpointResources, I changed the
internal API which took a WatchpointSP and devolved it to a Watchpoint*,
which meant touching several different Process files. I removed the
watchpoint code in ProcessKDP which only reported that watchpoints
aren't supported, the base class does that already.
I haven't yet changed how we receive a watchpoint to identify the
WatchpointResource responsible for the trigger, and identify all
Watchpoints that are using this Resource to evaluate their conditions
etc. This is the same work that a BreakpointSite needs to do when it has
been tiggered, where multiple Breakpoints may be at the same address.
There is not yet any printing of the Resources that a Watchpoint is
implemented in terms of ("watchpoint list", or
SBWatchpoint::GetDescription).
"watchpoint set var" and "watchpoint set expression" take a size
argument which was previously 1, 2, 4, or 8 (an enum). I've changed this
to an unsigned int. Most hardware implementations can only watch 1, 2,
4, 8 byte ranges, but with Resources we'll allow a user to ask for
different sized watchpoints and set them in hardware-expressble terms
soon.
I've annotated areas where I know there is work still needed with
LWP_TODO that I'll be working on once this is landed.
I've tested this on aarch64 macOS, aarch64 Linux, and Intel macOS.
https://discourse.llvm.org/t/rfc-large-watchpoint-support-in-lldb/72116
(cherry picked from commit fc6b72523f3d73b921690a713e97a433c96066c6)
...and follow ups.
As it has caused test failures on Linux Arm and AArch64:
https://lab.llvm.org/buildbot/#/builders/96/builds/49126https://lab.llvm.org/buildbot/#/builders/17/builds/45824
```
lldb-shell :: Subprocess/clone-follow-child-wp.test
lldb-shell :: Subprocess/fork-follow-child-wp.test
lldb-shell :: Subprocess/vfork-follow-child-wp.test
```
This reverts commit a6c62bf1a4717accc852463b664cd1012237d334,
commit a0a1ff3ab40e347589b4e27d8fd350c600526735 and commit
fc6b72523f3d73b921690a713e97a433c96066c6.
This patch is rearranging code a bit to add WatchpointResources to
Process. A WatchpointResource is meant to represent a hardware
watchpoint register in the inferior process. It has an address, a size,
a type, and a list of Watchpoints that are using this
WatchpointResource.
This current patch doesn't add any of the features of
WatchpointResources that make them interesting -- a user asking to watch
a 24 byte object could watch this with three 8 byte WatchpointResources.
Or a Watchpoint on 1 byte at 0x1002 and a second watchpoint on 1 byte at
0x1003, these must both be served by a single WatchpointResource on that
doubleword at 0x1000 on a 64-bit target, if two hardware watchpoint
registers were used to track these separately, one of them may not be
hit. Or if you have one Watchpoint on a variable with a condition set,
and another Watchpoint on that same variable with a command defined or
different condition, or ignorecount, both of those Watchpoints need to
evaluate their criteria/commands when their WatchpointResource has been
hit.
There's a bit of code movement to rearrange things in the direction I'll
need for implementing this feature, so I want to start with reviewing &
landing this mostly NFC patch and we can focus on the algorithmic
choices about how WatchpointResources are shared and handled as they're
triggeed, separately.
This patch also stops printing "Watchpoint <n> hit: old value: <x>, new
vlaue: <y>" for Read watchpoints. I could make an argument for print
"Watchpoint <n> hit: current value <x>" but the current output doesn't
make any sense, and the user can print the value if they are
particularly interested. Read watchpoints are used primarily to
understand what code is reading a variable.
This patch adds more fallbacks for how to print the objects being
watched if we have types, instead of assuming they are all integral
values, so a struct will print its elements. As large watchpoints are
added, we'll be doing a lot more of those.
To track the WatchpointSP in the WatchpointResources, I changed the
internal API which took a WatchpointSP and devolved it to a Watchpoint*,
which meant touching several different Process files. I removed the
watchpoint code in ProcessKDP which only reported that watchpoints
aren't supported, the base class does that already.
I haven't yet changed how we receive a watchpoint to identify the
WatchpointResource responsible for the trigger, and identify all
Watchpoints that are using this Resource to evaluate their conditions
etc. This is the same work that a BreakpointSite needs to do when it has
been tiggered, where multiple Breakpoints may be at the same address.
There is not yet any printing of the Resources that a Watchpoint is
implemented in terms of ("watchpoint list", or
SBWatchpoint::GetDescription).
"watchpoint set var" and "watchpoint set expression" take a size
argument which was previously 1, 2, 4, or 8 (an enum). I've changed this
to an unsigned int. Most hardware implementations can only watch 1, 2,
4, 8 byte ranges, but with Resources we'll allow a user to ask for
different sized watchpoints and set them in hardware-expressble terms
soon.
I've annotated areas where I know there is work still needed with
LWP_TODO that I'll be working on once this is landed.
I've tested this on aarch64 macOS, aarch64 Linux, and Intel macOS.
https://discourse.llvm.org/t/rfc-large-watchpoint-support-in-lldb/72116
This removes explicit invalidation of vg and svg that was done in
`GDBRemoteRegisterContext::AArch64Reconfigure`. This was in fact
covering up a bug elsehwere.
Register information says that a write to vg also invalidates svg (it
does not unless you are in streaming mode, but we decided to keep it
simple and say it always does).
This invalidation was not being applied until *after* AArch64Reconfigure
was called. This meant that without those manual invalidates this
happened:
* vg is written
* svg is not invalidated
* Reconfigure uses the written vg value
* Reconfigure uses the *old* svg value
I have moved the AArch64Reconfigure call to after we've processed the
invalidations caused by the register write, so we no longer need the
manual invalidates in AArch64Reconfigure.
In addition I have changed the order in which expedited registers as
parsed. These registers come with a stop notification and include,
amongst others, vg and svg.
So now we:
* Parse them and update register values (including vg and svg)
* AArch64Reconfigure, which uses those values, and invalidates every
register, because offsets may have changed.
* Parse the expedited registers again, knowing that none of the values
will have changed due to the scaling.
This means we use the expedited registers during the reconfigure, but
the invalidate does not mean we throw all of them away.
The cost is we parse them twice client side, but this is cheap compared
to a network packet, and is limited to AArch64 targets only.
On a system with SVE and SME, these are the packets sent for a step:
```
(lldb) b-remote.async> < 803> read packet:
$T05thread:p1f80.1f80;name:main.o;threads:1f80;thread-pcs:000000000040056c<...>a1:0800000000000000;d9:0400000000000000;reason:trace;#fc
intern-state < 21> send packet: $xfffffffff200,200#5e
intern-state < 516> read packet:
$e4f2ffffffff000000<...>#71
intern-state < 15> send packet: $Z0,400568,4#4d
intern-state < 6> read packet: $OK#9a
dbg.evt-handler < 16> send packet: $jThreadsInfo#c1
dbg.evt-handler < 224> read packet:
$[{"name":"main.o","reason":"trace","registers":{"161":"0800000000000000",<...>}],"signal":5,"tid":8064}]]#73
```
You can see there are no extra register reads which means we're using
the expedited registers.
For a write to vg:
```
(lldb) register write vg 4
lldb < 37> send packet:
$Pa1=0400000000000000;thread:1f80;#4a
lldb < 6> read packet: $OK#9a
lldb < 20> send packet: $pa1;thread:1f80;#29
lldb < 20> read packet: $0400000000000000#04
lldb < 20> send packet: $pd9;thread:1f80;#34
lldb < 20> read packet: $0400000000000000#04
```
There is the initial P write, and lldb correctly assumes that SVG is
invalidated by this also so we read back the new vg and svg values
afterwards.
I need to call this to figure out why the assert in
StopInfoMachException::CreateStopReasonWithMachException is triggering, but
it isn't appropriate to directly access the GDBRemoteCommunication there. And
dumping whatever history the process plugin has collected during the run isn't
gdb-remote specific...
Differential Revision: https://reviews.llvm.org/D154992
This teaches ProcessGDBRemote to look for "flags" nodes
in the target XML that tell you what fields a register has.
https://sourceware.org/gdb/onlinedocs/gdb/Target-Description-Format.html
It will check for various invalid inputs like:
* Flags nodes with 0 fields in them.
* Start or end being > the register size.
* Fields that overlap.
* Required properties not being present (e.g. no name).
* Flag sets being redefined.
If anything untoward is found, we'll just drop the field or the
flag set altogether. Register fields are a "nice to have" so LLDB
shouldn't be crashing because of them, instead just log anything
we throw away. So the user can fix their XML/file a bug with their
vendor.
Once that is done it will sort the fields and pass them to
the RegisterFields class I added previously.
There is no way to see these fields yet, so tests for this code
will come later when the formatting code is added.
The fields are stored in a map of unique pointers on the
ProcessGDBRemote class. It will give out raw pointers on the
assumption that the GDB process lives longer than the users
of those pointers do. Which means RegisterInfo is still a trivial struct
but we are properly destroying the fields when the GDB process ends.
We can't store the fields directly in the map because adding new
items may cause its storage to be reallocated, which would invalidate
pointers we've already given out.
Reviewed By: jasonmolenda, JDevlieghere
Differential Revision: https://reviews.llvm.org/D145574
lldb was originally designed to get the watchpoint exception behavior
from the gdb remote serial protocol stub -- exceptions are either
received before the instruction executes, or after the instruction
has executed. This behavior was reported via two lldb extensions
to gdb RSP, so generic remote stubs like gdbserver or a JTAG stub,
would not tell lldb which behavior was correct, and it would default
to "exceptions are received after the instruction has executed".
Two architectures hard coded their correct "exceptions before
instruction" behavior, to work around this issue.
Most architectures have a fixed behavior of watchpoint exceptions,
and we can center that information in lldb. We can allow a remote
stub to override the default behavior via our packet extensions
if it's needed on a specific target.
This patch also separates the fetching of the number of watchpoints
from whether exceptions are before/after the insn. Currently if
lldb couldn't fetch the number of watchpoints (not really needed), it
also wouldn't get when exceptions are received, and watchpoint
handling would fail. lldb doesn't actually use the number of
watchpoints for anything beyond printing it to the user.
Differential Revision: https://reviews.llvm.org/D143215
rdar://101426626
The remote stub may give lldb hints about binaries to
be loaded, especially in a firmware type environment, and
relay those hints in the qProcessInfo response. The
binary loading was done very early in Process setup, before
we had any threads, and this made it complicated for people
to write dSYM python scripts which need access to a thread.
Delay the binary loading until a bit later in the Process
startup.
Differential Revision: https://reviews.llvm.org/D141972
rdar://104235301
The dynamic linker on Darwin, dyld, can provide status of
the process state for a few significant points early on,
most importantly, when libSystem has been initialized and it
is safe to call functions behind the scenes. Pipe this
information up from debugserver to DynamicLoaderMacOS, for
the DynamicLoader::IsFullyInitialized() method, then have
Thread::SafeToCallFunctions use this information. Finally,
for the two utility functions in the AppleObjCRuntimeV2
LanguageRuntime plugin that I was fixing, call this method
before running our utility functions to collect the list of
objc classes registered in the runtime.
User expressions will still be allowed to run any time -
we assume the user knows what they are doing - but these
two additional utility functions that they are unaware of
will be limited by this state.
Differential Revision: https://reviews.llvm.org/D139054
rdar://102436092
can probably make function calls.
A common debugging pattern is to set a breakpoint that only stops after
a number of hits is recorded. The current implementation never resets
the hit count of breakpoints; as such, if a user re-`run`s their
program, the debugger will never stop on such a breakpoint again.
This behavior is arguably undesirable, as it renders such breakpoints
ineffective on all but the first run. This commit changes the
implementation of the `Will{Launch, Attach}` methods so that they reset
the _target's_ breakpoint hitcounts.
Differential Revision: https://reviews.llvm.org/D133858
Make constructors of the Process and its subclasses class protected,
to prevent accidentally constructing Process on stack when it could be
afterwards accessed via a shared_ptr (since it uses
std::enable_shared_from_this<>).
The only place where a stack allocation was used were unittests,
and fixing them via declaring an explicit public constructor
in the respective mock classes is trivial.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D131275
This reverts commit 7504dd5e00f514628614db8ee07514c73220e597.
In newer review feedback it was pointed out that there is a better API for this in Process::GetCodeAddressMask().
This patch adds a getter for the process' system architecture. I went
with Process::GetSystemArchitecture to match
Platform::GetSystemArchitecture.
Differential revision: https://reviews.llvm.org/D121443
This workaround is the source of an awkwared Process->Platform
dependency. While this could be solved in various ways (the only thing
we really use is the plugin name), it may be better to just remove it --
the workaround was added 10 years ago (43c555dfc), and the affected
debugservers were "old" even then, so hopefully they are not in use
anymore.
Differential Revision: https://reviews.llvm.org/D121305
All current callers set the argument to false. monitor_signals=true used
to be used in the Process plugins (which needed to know when the
debugged process gets a signal), but this implementation has several
serious issues, which means that individual process plugins now
orchestrate the monitoring of debugged processes themselves.
This allows us to simplify the implementation (no need to play with
process groups), and the interface (we only catch fatal events, so the
callback is always called just once).
Differential Revision: https://reviews.llvm.org/D120425
Accept a function object instead of a raw pointer. This avoids a bunch
of boilerplate typically needed to pass arguments to the thread
functions.
Differential Revision: https://reviews.llvm.org/D120321
This reverts commit 0df522969a7a0128052bd79182c8d58e00556e2f.
Additional checks are added to fix the detection of the last memory region
in GetMemoryRegions or repeating the "memory region" command when the
target has non-address bits.
Normally you keep reading from address 0, looking up each region's end
address until you get LLDB_INVALID_ADDR as the region end address.
(0xffffffffffffffff)
This is what the remote will return once you go beyond the last mapped region:
[0x0000fffffffdf000-0x0001000000000000) rw- [stack]
[0x0001000000000000-0xffffffffffffffff) ---
Problem is that when we "fix" the lookup address, we remove some bits
from it. On an AArch64 system we have 48 bit virtual addresses, so when
we fix the end address of the [stack] region the result is 0.
So we loop back to the start.
[0x0000fffffffdf000-0x0001000000000000) rw- [stack]
[0x0000000000000000-0x0000000000400000) ---
To fix this I added an additional check for the last range.
If the end address of the region is different once you apply
FixDataAddress, we are at the last region.
Since the end of the last region will be the last valid mappable
address, plus 1. That 1 will be removed by the ABI plugin.
The only side effect is that on systems with non-address bits, you
won't get that last catch all unmapped region from the max virtual
address up to 0xf...f.
[0x0000fffff8000000-0x0000fffffffdf000) ---
[0x0000fffffffdf000-0x0001000000000000) rw- [stack]
<ends here>
Though in some way this is more correct because that region is not
just unmapped, it's not mappable at all.
No extra testing is needed because this is already covered by
TestMemoryRegion.py, I simply forgot to run it on system that had
both top byte ignore and pointer authentication.
This change has been tested on a qemu VM with top byte ignore,
memory tagging and pointer authentication enabled.
Reviewed By: omjavaid
Differential Revision: https://reviews.llvm.org/D115508
This reverts commit fac3f20de55769d028bd92220e74f22fa57dd4b2.
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.
This reverts commit 5fbcf677347e38718461496d9e9e184a7a30c3fb.
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
There is no reason why this function should be returning a ConstString.
While modifying these files, I also fixed several instances where
GetPluginName and GetPluginNameStatic were returning different strings.
I am not changing the return type of GetPluginNameStatic in this patch, as that
would necessitate additional changes, and this patch is big enough as it is.
Differential Revision: https://reviews.llvm.org/D111877
Call ABI::AugmentRegisterInfo() once with a vector of all defined
registers rather than calling it for every individual register. Move
and rename RemoteRegisterInfo from gdb-remote to
DynamicRegisterInfo::Register, and use this class when augmenting
registers.
Differential Revision: https://reviews.llvm.org/D111142
