Moves breakpoindIDCounter out of BreakpointsMap and into
service/debugger.Debuggger to simplify proc.Target's API and aid with
implementing fork follow mode, where we'll have to debug multiple
processes simultaneously.
This commit improves the handling of hardcoded breakpoints in Delve.
A hardcoded breakpoint is a breakpoint instruction hardcoded in the
text of the program, for example through runtime.Breakpoint.
1. hardcoded breakpoints are now indicated by setting the breakpoint
field on any thread stopped by a hardcoded breakpoint
2. if multiple hardcoded breakpoints are hit during a single stop all
will be notified to the user.
3. a debugger breakpoint with an unmet condition can't hide a hardcoded
breakpoint anymore.
* service/debugger: fix bug internal err with Restart on recorded target
If Restart is called after a Continue and Rewind on a recorded target
that has already terminated it will return an internal error.
* proc/gdbserial: allow rewind to work after process exit with rr
It is sometimes useful to set breakpoints and rewind a terminated
process when using rr, for example if interested in the last execution
of some function.
RR will not allow a backward continue after the process exit packet has
been sent, however rr will also generate a synthetic SIGKILL right
before process exit.
Treat this packet as a process exit and change some things so both
continuing backwards and setting breakpoints can be done, on recorded
targets, after process exit has been reported.
Fix signal handling during thread single stepping so that signals that
are generated by executing the current instruction are immediately
propagated to the inferior, while signals other signals sent to the
thread are delayed until the full resume happens.
Fixes a bug where a breakpoint set on an instruction that causes a
SIGSEGV would make Delve hang and a bug where signals received during
single step would make it look like an instruction is executed twice.
Fixes#2801Fixes#2792
* made Pid a method of Target instead of a method of Process
* changed argument of NewTarget to ProcessInternal, since that's the
interface that backends have to implement
* removed warnings about ProcessInternal since there is no way for
users of pkg/proc to access those methods anyway
* made RecordingManipulation an optional interface for backends, Target
supplies its own dummy implementation when the backend doesn't
* inlined small interfaces that only existed to be inlined in
proc.Process anyway
* removed unused function findExecutable in the Windows and no-native
darwin backends
* removed (*EvalScope).EvalVariable, an old synonym for EvalExpression
Debugserver has a bug where writing to a AVX-2 or AVX-512 register does
not work unless it is followed by at least a write to a AVX (not 2 or
512) register.
See also: https://bugs.llvm.org/show_bug.cgi?id=52362Fixes#2767
Normally calls can't be performed on recorded processes, becuase the
future instructions executed by the target are predetermined. The rr
debugger however has a mechanism that allows this by taking the current
state of the recording and allowing it to diverge from the recording,
temporarily.
This commit adds support for starting and ending such diversions around
function calls.
Note: this requires rr version 5.5 of later to work, see:
https://github.com/rr-debugger/rr/pull/2748
Adds watchpoint support to gdbserver backend for rr debugger and
debugserver on macOS/amd64 and macOS/arm64.
Also changes stack watchpoints to support reverse execution.
Internal breakpoints do not need IDs and assigning them from a counter
separate from the user ID counter can be a cause of confusion.
If a user breakpoint is overlayed on top of a pre-existing internal
breakpoint the temporary ID will be surfaced as if it was a user ID,
possibly conflicting with another user ID.
If a temporary breakpoint is overlayed on top of a pre-existing user
breakpoint and the user breakpoint is first deleted and then
re-created, the user ID will be resurrected along with the breakpoint,
instead of allocating a fresh one.
This change removes internal breakpoint IDs entirely, only user
breakpoints receive an ID.
This patch enables the eBPF tracer backend to parse the ID of the
Goroutine which hit the uprobe. This implementation is specific to AMD64
and will have to be generalized further in order to be used on other
architectures.
* proc: move breakpoint condition evaluation out of backends
Moves breakpoint condition evaluation from the point where breakpoints
are set, inside ContinueOnce, to (*Target).Continue.
This accomplishes three things:
1. the breakpoint evaluation method needs not be exported anymore
2. breakpoint condition evaluation can be done with a full scope,
containing a Target object, something that wasn't possible before
because ContinueOnce doesn't have access to the Target object.
3. moves breakpoint condition evaluation out of the critical section
where some of the threads of the target process might be still
running.
* proc/native: handle process death during stop() on Windows
It is possible that the thread dies while we are inside the stop()
function. This results in an Access is denied error being returned by
SuspendThread being called on threads that no longer exist.
Delay the reporting the error from SuspendThread until the end of
stop() and only report it if the thread still exists at that point.
Fixes flakyness with TestIssue1101 that was exacerbated by moving
breakpoint condition evaluation outside of the backends.
Changes Breakpoint to allow multiple overlapping internal breakpoints
on the same instruction address.
This is done by changing the Breakpoint structure to contain a list of
"breaklets", each breaklet has a BreakpointKind and a condition
expression, independent of the other.
A breakpoint is considered active if any of its breaklets are active.
A breakpoint is removed when all its breaklets are removed.
We also change the terminology "internal breakpoint" to "stepping
breakpoint":
HasInternalBreakpoints -> HasSteppingBreakpoints
IsInternal -> IsStepping
etc...
The motivation for this change is implementing watchpoints on stack
variables.
Watching a stack variable requires also setting a special breakpoint to
find out when the variable goes out of scope. These breakpoints can not
be UserBreakpoints because only one user breakpoint is allowed on the
same instruction and they can not be internal breakpoints because they
should not be cleared when a next operation is completed (they should
be cleared when the variable watch is cleared).
Updates #279
This PR aims to add support for rr replay and core actions from the DAP layer. This basically encloses the following:
New launch modes: replay and core
The following modes are added:
replay: Replays an rr trace, allowing backwards flows (reverse continue and stepback). Requires a traceDirPath property on launch.json pointing to a valid rr trace directory.
Equivalent to dlv replay <tracedir> command.
core: Replays a core dump file, showing its callstack and the file matching the callsite. Requires a coreFilePath property on launch.json pointing to a valid coredump file.
Equivalent to dlv core <exe> <corefile> command.
Dependencies
To achieve this the following additional changes were made:
Implement the onStepBackRequest and onReverseContinueRequest methods on service/dap
Adapt onLaunchRequest with the requried validations and logic for these new modes
Use CapabilitiesEvent responses to enable the StepBack controls on the supported scenarios (see dicussion here)
Add the corresponding launch.json support on vs code:
Support for replay and core modes golang/vscode-go#1268
* pkg/proc: implement support for hit count breakpoints
* update comment
* udpate hitcount comment
* update HitCond description
* add test for hit condition error
* respond to review
* service/dap: add support for hit count breakpoints
* use amendbps to preserve hit counts
* update test health doc
* fix failing test
* simplify hit conditions
* REmove RequestString, use name instead
* update backend_test_health.md
* document hit count cond
* fix tests
Adds DWARF register number and support for AVX-512 registers.
Changes proc/gdbserial so that the 'g' and 'G' commands are never used
with debugserver since they seem to corrupt the thread state when used
on AVX-512 capable hardware.
Also changes TestClientServer_FpRegisters to be simpler and more
resilient to changes to the Go runtime.
Fixes#2479
The maintainer of debugserver says he wants to fix the problem with the
'g' command but doesn't know when it will happen. Treat the error 'E74'
for the 'g' command on debugserver as if the server had returned an
unsupported error so that, for this specific problem, the error doesn't
resurface in the future.
Adds the low-level support for watchpoints (aka data breakpoints) to
the native linux/amd64 backend.
Does not add user interface or functioning support for watchpoints
on stack variables.
Updates #279
We have some places where we use proc.ErrProcessExited and some places
that use &proc.ErrProcessExited, resulting in checks for process exited
errors occasionally failing on some architectures.
Uniform use of ErrProcessExited to the non-pointer version.
Fixes intermittent failure of TestStepOutPreservesGoroutine.
Delve represents registerized variables (fully or partially) using
compositeMemory, implementing proc.(*compositeMemory).WriteMemory is
necessary to make SetVariable and function calls work when Go will
switch to using the register calling convention in 1.17.
This commit also makes some refactoring by moving the code that
converts between register numbers and register names out of pkg/proc
into a different package.
* proc/core: off-by-one error reading ELF core files
core.(*splicedMemory).ReadMemory checked the entry interval
erroneously when dealing with contiguous entries.
* terminal,service,proc/*: adds dump command (gcore equivalent)
Adds the `dump` command that creates a core file from the target process.
Backends will need to implement a new, optional, method `MemoryMap` that
returns a list of mapped memory regions.
Additionally the method `DumpProcessNotes` can be implemented to write out
to the core file notes describing the target process and its threads. If
DumpProcessNotes is not implemented `proc.Dump` will write a description of
the process and its threads in a OS/arch-independent format (that only Delve
understands).
Currently only linux/amd64 implements `DumpProcessNotes`.
Core files are only written in ELF, there is no minidump or macho-o writers.
# Conflicts:
# pkg/proc/proc_test.go
* add -json flag when running tests on TeamCity
* introduce TeamCity builds
* restore gdbserial constants for 386
Otherwise compilation fails.
* skip TestAttachRequest on Windows as it never finishes
* run tests on 1.16beta1
* Use the active xcode-select path instead of a hardcoded Xcode path
* Refactored exec.Command to invoke Output instead of running with a custom buffer for stdout
Addresses review comment by @derekparker
1. Forward stdin/stdout/stderr to the target process when in foreground
mode instead of always forwarding the current tty (issue #1964)
2. When redirecting a file descriptor make sure to also specify
something for all three otherwise debugserver will misbehave (either
exit on launch or run but giving the target process a closed file
descriptor).
Fixes#1964
On linux we can not read memory if the thread we use to do it is
occupied doing certain system calls. The exact conditions when this
happens have never been clear.
This problem was worked around by using the Blocked method which
recognized the most common circumstances where this would happen.
However this is a hack: Blocked returning true doesn't mean that the
problem will manifest and Blocked returning false doesn't necessarily
mean the problem will not manifest. A side effect of this is issue
#2151 where sometimes we can't read the memory of a thread and find its
associated goroutine.
This commit fixes this problem by always reading memory using a thread
we know to be good for this, specifically the one returned by
ContinueOnce. In particular the changes are as follows:
1. Remove (ProcessInternal).CurrentThread and
(ProcessInternal).SetCurrentThread, the "current thread" becomes a
field of Target, CurrentThread becomes a (*Target) method and
(*Target).SwitchThread basically just sets a field Target.
2. The backends keep track of their own internal idea of what the
current thread is, to use it to read memory, this is the thread they
return from ContinueOnce as trapthread
3. The current thread in the backend and the current thread in Target
only ever get synchronized in two places: when the backend creates a
Target object the currentThread field of Target is initialized with the
backend's current thread and when (*Target).Restart gets called (when a
recording is rewound the currentThread used by Target might not exist
anymore).
4. We remove the MemoryReadWriter interface embedded in Thread and
instead add a Memory method to Process that returns a MemoryReadWriter.
The backends will return something here that will read memory using
the current thread saved by the backend.
5. The Thread.Blocked method is removed
One possible problem with this change is processes that have threads
with different memory maps. As far as I can determine this could happen
on old versions of linux but this option was removed in linux 2.5.
Fixes#2151
During the testing of the core dump generation feature two bugs were
discovered in gdbserial:
1. we don't check that both bytes of the checksum are read, if the
buffer only has one byte we can end up reading only one byte instead
of two and the second byte will mess up the parsing of the next
packet
2. binary encoded packets can start with an 'E' and not be errors, when
using binary responses add an extra check for the lenght of the
response before deciding that the response is an error.
Unfortunately this encoding is inherently ambiguous (we can't
distinguish a 3 byte response starting with 'E' from an error) so
binary requests that lead to short responses should be avoided.
Testing this is complicated, they will be tested implicitly by the
upcoming core dump test.
Co-authored-by: a <a@kra>
Since proc is supposed to work independently from the target
architecture it shouldn't use architecture-dependent types, like
uintptr. For example when reading a 64bit core file on a 32bit
architecture, uintptr will be 32bit but the addresses proc needs to
represent will be 64bit.
Adds features to support default file descriptor redirects for the
target process:
1. A new command line flag '--redirect' and '-r' are added to specify
file redirects for the target process
2. New syntax is added to the 'restart' command to specify file
redirects.
3. Interactive instances will check if stdin/stdout and stderr are
terminals and print a helpful error message if they aren't.
Recent changes to the way registers are handled broke reporting of AVX
registers (i.e. YMMx). This change restores the functionality by:
- concatenating the higher half of the YMMx registers to their
corresponding XMMx lower half (YMMx registers do not have an
independent DWARF register number)
- modifying the formatSSEReg function to handle them when they are
present.
Fixes#2033
These methods only work if registers have been loaded once after the
last resume, there's probably no code path that calls SetXX before
Thread.Registers but lets make sure it can't happen anyway.
Changes implementations of proc.Registers interface and the
op.DwarfRegisters struct so that floating point registers can be loaded
only when they are needed.
Removes the floatingPoint parameter from proc.Thread.Registers.
This accomplishes three things:
1. it simplifies the proc.Thread.Registers interface
2. it makes it impossible to accidentally create a broken set of saved
registers or of op.DwarfRegisters by accidentally calling
Registers(false)
3. it improves general performance of Delve by avoiding to load
floating point registers as much as possible
Floating point registers are loaded under two circumstances:
1. When the Slice method is called with floatingPoint == true
2. When the Copy method is called
Benchmark before:
BenchmarkConditionalBreakpoints-4 1 4327350142 ns/op
Benchmark after:
BenchmarkConditionalBreakpoints-4 1 3852642917 ns/op
Updates #1549
