...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
The previous version of the patch did not update the definitions in
conditionally compiled code. This patch includes changes to ARC and
windows targets.
Original commit message was:
These were added to support some mips registers on linux, but linux mips
support has now been removed due.
They are still referenced in the freebds mips implementation, but the
completeness of that implementation is also unknown. All other
architectures just set these fields to zero, which is a cause of
significant bloat in our register info definitions.
Arm also has registers with variable sizes, but they were implemented in
a more gdb-compatible fashion and don't use this feature.
Differential Revision: https://reviews.llvm.org/D110914
This reverts commit 00e704bf080ffeeb9e334fb3ab71594f9aa50969.
This commit should should have updated
llvm/llvm-project/lldb/source/Plugins/ABI/ARC/ABISysV_arc.cpp like the other
architectures.
These were added to support some mips registers on linux, but linux mips
support has now been removed due.
They are still referenced in the freebds mips implementation, but the
completeness of that implementation is also unknown. All other
architectures just set these fields to zero, which is a cause of
significant bloat in our register info definitions.
Arm also has registers with variable sizes, but they were implemented in
a more gdb-compatible fashion and don't use this feature.
Differential Revision: https://reviews.llvm.org/D110914
We added some support for this mode back in 2015, but the feature was
never productionized. It is completely untested, and there are known
major structural lldb issues that need to be resolved before this
feature can really be supported.
It also complicates making further changes to stop reply packet
handling, which is what I am about to do.
Differential Revision: https://reviews.llvm.org/D110553
Replace the uses of StringConvert combined with hand-rolled array
splitting with llvm::StringRef.split() and llvm::to_integer().
Differential Revision: https://reviews.llvm.org/D110472
Refactor remote register getters to collect them into a local
std::vector rather than adding them straight into DynamicRegisterInfo.
The purpose of this change is to lay groundwork for switching value_regs
and invalidate_regs to use local LLDB register numbers rather than
remote numbers.
Differential Revision: https://reviews.llvm.org/D110025
Refactor remote register getters to collect them into a local
std::vector rather than adding them straight into DynamicRegisterInfo.
The purpose of this change is to lay groundwork for switching value_regs
and invalidate_regs to use local LLDB register numbers rather than
remote numbers.
Differential Revision: https://reviews.llvm.org/D110025
In all these years, we haven't found a use for this function (it has
zero callers). Lets just remove the boilerplate.
Differential Revision: https://reviews.llvm.org/D109600
Extend PluginManager::SaveCore() to support saving core dumps
via Process plugins. Implement the client-side part of qSaveCore
request in the gdb-remote plugin, that creates the core dump
on the remote host and then uses vFile packets to transfer it.
Differential Revision: https://reviews.llvm.org/D101329
Implement a new target.process.follow-fork-mode setting to control
LLDB's behavior on fork. If set to 'parent', the forked child is
detached and parent continues being traced. If set to 'child',
the parent is detached and child becomes traced instead.
Differential Revision: https://reviews.llvm.org/D100503
Temporarily remove breakpoints for the duration of vfork, in order
to prevent them from triggering in the child process. Restore them
once the server reports that vfork has finished and it is ready to
resume execution.
Differential Revision: https://reviews.llvm.org/D100267
Temporarily remove breakpoints for the duration of vfork, in order
to prevent them from triggering in the child process. Restore them
once the server reports that vfork has finished and it is ready to
resume execution.
Differential Revision: https://reviews.llvm.org/D100267
Remove software breakpoints from forked processes in order to restore
the original program code before detaching it.
Differential Revision: https://reviews.llvm.org/D100263
Add a support for handling fork/vfork stops in LLGS client. At this
point, it only sends a detach packet for the newly forked child
(and implicitly resumes the parent).
Differential Revision: https://reviews.llvm.org/D100206
This adds memory tag writing to Process and the
GDB remote code. Supporting work for the
"memory tag write" command. (to follow)
Process WriteMemoryTags is similair to ReadMemoryTags.
It will pack the tags then call DoWriteMemoryTags.
That function will send the QMemTags packet to the gdb-remote.
The QMemTags packet follows the GDB specification in:
https://sourceware.org/gdb/current/onlinedocs/gdb/General-Query-Packets.html#General-Query-Packets
Note that lldb-server will be treating partial writes as
complete failures. So lldb doesn't need to handle the partial
write case in any special way.
Reviewed By: omjavaid
Differential Revision: https://reviews.llvm.org/D105181
This adds GDB client support for the qMemTags packet
which reads memory tags. Following the design
which was recently committed to GDB.
https://sourceware.org/gdb/current/onlinedocs/gdb/General-Query-Packets.html#General-Query-Packets
(look for qMemTags)
lldb commands will use the new Process methods
GetMemoryTagManager and ReadMemoryTags.
The former takes a range and checks that:
* The current process architecture has an architecture plugin
* That plugin provides a MemoryTagManager
* That the range of memory requested lies in a tagged range
(it will expand it to granules for you)
If all that was true you get a MemoryTagManager you
can give to ReadMemoryTags.
This two step process is done to allow commands to get the
tag manager without having to read tags as well. For example
you might just want to remove a logical tag, or error early
if a range with tagged addresses is inverted.
Note that getting a MemoryTagManager doesn't mean that the process
or a specific memory range is tagged. Those are seperate checks.
Having a tag manager just means this architecture *could* have
a tagging feature enabled.
An architecture plugin has been added for AArch64 which
will return a MemoryTagManagerAArch64MTE, which was added in a
previous patch.
Reviewed By: omjavaid
Differential Revision: https://reviews.llvm.org/D95602
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
Add a minimal support for the multiprocess extension in gdb-remote
client. It accepts PIDs as part of thread-ids, and rejects PIDs that
do not match the current inferior.
Differential Revision: https://reviews.llvm.org/D99603
