* 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
There are persistent issues with watchpoints on Windows, it is not
clear whether it's a problem with the VM running the tests or if there
is a real bug in our implementation of hardware breakpoints on Windows.
Until the cause can be determined watchpoints on Windows will be
disabled.
Updates #2768
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
* proc/native: always stop after RequestManualStop on Windows
On Windows RequestManualStop will generate an exception on a special
DbgUiRemoteBreakin thread, sometimes this thread will die before we
finish stopping the process. We need to account for that and still stop
even if the thread is gone and no other thread hit a breakpoint.
Fixes flakiness of TestIssue419.
* proc/native: fix watchpoints with new threads on Windows
When a new thread is created we must reapply all watchpoints to it,
like we do on linux.
* tests: be lenient on goroutinestackprog tests on Windows
We can not guarantee that we find all goroutines stopped in a good
place and sometimes the stacktrace fails on Windows.
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.
* 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
A RequestManualStop received while the target program is stopped can
induce a crash when the target is restarted.
This is caused by the phantom breakpoint detection that was introduced
in PR #2179 / commit e69d536.
Instead of always interpreting an unexplained SIGTRAP as a phantom
breakpoint memorize all possible unreported breakpoint hits and only
act on it when the thread hasn't moved from one.
Also clarifies the behavior of the halt command when it is received
while the target is stopped or in the process of stopping.
Handle the signaled status for the thread leader like we handle the
exited status, by returning ErrProcessExited and recording the killer
signal in it.
Prior to this commit we would find out about the death of the thread
later in the loop, the condition would still be reported as
ErrProcessExited, but without recording the signal number anywhere.
Also fixes a bug in TestAttachStopOnEntry where the test would
inadvertently cause a SIGPIPE to be sent to the target process, making
it terminate early.
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.
When cgo is used the address of the g struct is saved on the special
register TPIDR_EL0. Because executing C code could overwrite the
contents of R28 that normally contains the address of g we should read
it from TPIDR_EL0 instead when runtime.iscgo is set.
* 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
If a thread exits while we are looking at it just treat it as if the
status had reported it as exited instead of doing something special.
Fixes flakiness in TestIssue387.
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
TestStepConcurrentDirect will occasionally fail (7% of the time on my
setup) by either causing the target processs to execute an invalid
instruction or (more infrequently) by switching to the wrong thread.
Both of those are caused by receiving SIGTRAPs for threads hitting a
breakpoint after it has been removed (the thread hits the breakpoint,
we stop everything and remove the breakpoint and only after we receive
the signal).
Change native.(*nativeProcess).stop to handle SIGTRAPs that can't be
attributed to a breakpoint, a hardcoded breakpoint in the program's
text, or manual stops (and therefore are likely caused by phantom
breakpoint hits).
Co-authored-by: a <a@kra>
If the process receives a signal (or sends a singal to itself) and then
dies before we can route the signal back to it we still need to
retrieve its exit status.
Fixes a rare failure of TestIssue1101 in proc_test.go
Co-authored-by: a <a@kra>
* Revert "proc: Find executable should follow symbol links."
This reverts commit 3e04ad0fada0c3ab57caf58bc024e4c0f9a3e01a.
* proc: resolve symlinks when searching for split debug_info if path is /proc/pid/exe
Fixes#2168
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.
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
On linux platform, we simply treated `/proc/$pid/exe` as the
executable of targeting process when doing `dlv attach`. The
`/proc/$pid/exe` is a symbol link of the real executable file.
Delve couldn't find the corrsponding external debug file based on the
symbol link:
```
could not attach to pid $pid: could not open debug info
```
The fix is to evaluate the symbol links to the actual executable path.
The process could quit while we are inside stop, we should report the
error otherwise the following code will try to send on the closed
ptrace channel.
Fixes a sporadic error in TestIssue1101.
This flag allows users on UNIX systems to set the tty for the program
being debugged by Delve. This is useful for debugging command line
applications which need access to their own TTY, and also for
controlling the output of the debugged programs so that IDEs may open a
dedicated terminal to show the output for the process.
* *: Fix go vet struct complaints
* *: Fix struct vet issue on linux
* *: Ignore proc/native in go vet check
We have to do some unsafe pointer manipulation that will never make go
vet happy within the proc/native package. Ignore it for runs of go vet.
* proc: move defer breakpoint code into a function
Moves the code that sets a breakpoint on the first deferred function,
used by both next and StepOut, to its function.
* proc: implement reverse step/next/stepout
When the direction of execution is reversed (on a recording) Step, Next and
StepOut will behave similarly to their forward version. However there are
some subtle interactions between their behavior, prologue skipping, deferred
calls and normal calls. Specifically:
- when stepping backwards we need to set a breakpoint on the first
instruction after each CALL instruction, once this breakpoint is reached we
need to execute a single StepInstruction operation to reverse step into the
CALL.
- to insure that the prologue is skipped reverse next needs to check if it
is on the first instruction after the prologue, and if it is behave like
reverse stepout.
- there is no reason to set breakpoints on deferred calls when reverse
nexting or reverse stepping out, they will never be hit.
- reverse step out should generally place its breakpoint on the CALL
instruction that created the current stack frame (which will be the CALL
instruction immediately preceding the instruction at the return address).
- reverse step out needs to treat panic calls and deferreturn calls
specially.
* service,terminal: implement reverse step, next, stepout
* proc,proc/*: move SelectedGoroutine to proc.Target, remove PostInitializationSetup
moves SelectedGoroutine, SwitchThread and SwitchGoroutine to
proc.Target, merges PostInitializationSetup with NewTarget.
* proc,proc/*: add StopReason field to Target
Adds a StopReason field to the Target object describing why the target
process is currently stopped. This will be useful for the DAP server
(which needs to report this reason in one of its requests) as well as
making pull request #1785 (reverse step) conformant to the new
architecture.
* proc: collect NewTarget arguments into a struct
Implement debugging function for 386 on linux with reference to AMD64.
There are a few remaining problems that need to be solved in another time.
1. The stacktrace of cgo are not exactly as expected.
2. Not implement `core` for now.
3. Not implement `call` for now. Can't not find `runtime·debugCallV1` or
similar function in $GOROOT/src/runtime/asm_386.s.
Update #20
* proc/native/linux: only set breakpoints on threads that receive SIGTRAP
* proc/native/linux: do not call (*Thread).Stopped inside (*Process).stop
(*Thread).Stopped is slow because it needs to open, read and parse a
file in /proc, we don't actually need to do that, we can just rely on
the value of Thread.os.running.
Benchmark before:
BenchmarkConditionalBreakpoints-4 1 12476166303 ns/op
Benchmark after:
BenchmarkConditionalBreakpoints-4 1 10403533675 ns/op
Conditional breakpoint evaluation: 1.24ms -> 1ms
Updates #1549
This change adds `ProcessVmRead` and `ProcessVmWrite` wrappers around
the syscalls `process_vm_readv` and `process_vm_writev`, available since
Linux 3.2. These follow the same permission model as `ptrace`, but they
don't actually require being attached, which means they can be called
directly from any thread in the debugger. They also use `iovec` to write
entire blocks at once, rather than having to peek/poke each `uintptr`.
These wrappers are used in `Thread.ReadMemory` and `WriteMemory`, still
falling back to `ptrace` if that fails for any reason. Notably,
`process_vm_writev` respects memory protection, so it can't modify
read-only memory like `ptrace`. This frequently occurs when writing
breakpoints in read-only `.text`, so to avoid a lot of wasted `EFAULT`
calls, we only try `process_vm_writev` for larger writes.
As we rearrange the code and the Go compiler changes the error message
returned by the compiler on unsupported architectures will change too,
making it un-googlable. Since the error message tends to be rather
obscure too this regularly confuses newbies.
This is an effort to make the error message for unsupported GOOS/GOARCH
combinations the same across all unsupported combinations and to make
it more user friendly.
Directories containing Go source code are supposed to contain a single
package. This property happens to be checked by cmd/go itself so it
will happen even before the syntax is fully checked and therefore has a
high probability of being the first (and only) error message being
print.
Here we take advantage of this by adding to the pkg/proc/native
directory a file with a bad package line that only gets compiled in on
unsupported GOOS/GOARCH combinations.
At present the error message for compiling Delve on unsupported systems
will be:
service/debugger/debugger.go:21:2: found packages native (proc.go) and your_operating_system_and_architecture_combination_is_not_supported_by_delve (support_sentinel.go) in $PATH_TO_DELVE/pkg/proc/native
A significant amount of time is spent generating the string
representation for the proc.Registers object of each thread, since this
field is rarely used (only when the Registers API is called) it should
be generated on demand.
Also by changing the internal representation of proc.Register to be
closer to that of op.DwarfRegister it will help us implement #1838
(when Delve will need to be able to display the registers of an
internal frame, which we currently represent using op.DwarfRegister
objects).
Benchmark before:
BenchmarkConditionalBreakpoints-4 1 22292554301 ns/op
Benchmark after:
BenchmarkConditionalBreakpoints-4 1 17326345671 ns/op
Reduces conditional breakpoint latency from 2.2ms to 1.7ms.
Updates #1549, #1838
* tests: misc test fixes for go1.14
- math.go is now ambiguous due to changes to the go runtime so specify
that we mean our own math.go in _fixtures
- go list -m requires vendor-mode to be disabled so pass '-mod=' to it
in case user has GOFLAGS=-mod=vendor
- update version of go/packages, required to work with go 1.14 (and
executed go mod vendor)
- Increased goroutine migration in one development version of Go 1.14
revealed a problem with TestCheckpoints in command_test.go and
rr_test.go. The tests were always wrong because Restart(checkpoint)
doesn't change the current thread but we can't assume that when the
checkpoint was taken the current goroutine was running on the same
thread.
* goversion: update maximum supported version
* Makefile: disable testing lldb-server backend on linux with Go 1.14
There seems to be some incompatibility with lldb-server version 6.0.0
on linux and Go 1.14.
* proc/gdbserial: better handling of signals
- if multiple signals are received simultaneously propagate all of them to the
target threads instead of only one.
- debugserver will drop an interrupt request if a target thread simultaneously
receives a signal, handle this situation.
* dwarf/line: normalize backslashes for windows executables
Starting with Go 1.14 the compiler sometimes emits backslashes as well
as forward slashes in debug_line, normalize everything to / for
conformity with the behavior of previous versions.
* proc/native: partial support for Windows async preempt mechanism
See https://github.com/golang/go/issues/36494 for a description of why
full support for 1.14 under windows is problematic.
* proc/native: disable Go 1.14 async preemption on Windows
See https://github.com/golang/go/issues/36494
* pkg/proc: Introduce Target
* pkg/proc: Remove Common.fncallEnabled
Realistically we only block it on recorded backends.
* pkg/proc: Move fncallForG to Target
* pkg/proc: Remove CommonProcess
Remove final bit of functionality stored in CommonProcess and move it to
*Target.
* pkg/proc: Add SupportsFunctionCall to Target
Specifically, make sure that both DebugActiveProcess and
WaitForDebugEvent Windows APIs are executed on the same thread.
Otherwise WaitForDebugEvent fails with ERROR_INVALID_HANDLE as per its
documentation
https://docs.microsoft.com/en-us/windows/win32/api/debugapi/nf-debugapi-waitfordebugevent
'... Only the thread that created the process being debugged can call
WaitForDebugEvent. ...'
Fixes#1825
When attaching to a process in linux ElfUpdateSharedObjects will be
called for the first time during the call to updateThreadList,
unfortunately it won't do anything because the dynamic section of the
base elf executable needs to have been read first and that's done when
we initialize the BinaryInfo object (which happens later during the
call to initialize).
arm64 use hardware breakpoint, and it will not set PC to the next instruction like amd64. Let adjustPC always fasle in arm64, in case of infinite loop.
* delve now can be built to arm64-arch and running on linux-arm64 OS.
* arm64 general-purpose registers have completed.
* arm64 disasm has completed.
Co-authored-by: tykcd996 <tang.yuke@zte.com.cn>
Co-authored-by: hengwu0 <wu.heng@zte.com.cn>
As proc/native is arch related, it should move some functions to arch-relate file. And this patch can help us to separate the architecture code, make code tidy. So that the merge of arm64 code later will not cause chaos.(#118)
* proc/linux: do not route signals to threads while stopping
While we are trying to stop the process we should not route signals
sent to threads because that will result in threads being resumed.
Also keep better track of which threads are stopped.
This fixes an incompatibility with Go 1.14, which sends a lot of
signals to its threads to implement non-cooperative preemption,
resulting in Delve hanging waiting for an already-stopped thread to
stop.
In principle however this bug has nothing to do with Go 1.14 and could
manifest in any instance of high signal pressure.
* Makefile: discard stderr of "go list"
In module mode "go" will print messages about downloading modules to
stderr, we shouldn't confuse them for the real command output.
Fixes a case of breakpoint confusion on resume caused by having two
breakpoints one byte apart. This bug can cause the target program to
resume execution a single byte inside an instruction and crash either
with SIGILL or a SIGSEGV, or misbehave (depending on how the truncated
instruction is decoded).
native.(*Thread).StepInstruction should call FindBreakpoint using
adjustPC==false because at that point the PC of the thread should
already have been adjusted (and it has been).
proc.Next and proc.Step will call, after setting their temp
breakpoints, curthread.SetCurrentBreakpoint. This is intended to find
if one of the newly created breakpoints happens to be at the same
instruction that curthread is stopped at.
However SetCurrentBreakpoint is intended to be called after a Continue
and StepInstruction operation so it will also detect if curthread is
stopped one byte after a breakpoint.
If the instruction immediately preceeding the current instruction of
curthread happens to:
1. have one of the newly created temp breakpoints
2. be one byte long
SetCurrentBreakpoint will believe that we just hit that breakpoint and
therefore the instruction should be repeated, and thus rewind the PC of
curthread by 1.
We should distinguish between the two uses of SetCurrentBreakpoint and
disable the check for "just hit" breakpoints when inappropriate.
Fixes#1656
RestoreRegisters on linux would also restore FS_BASE and GS_BASE, if
the target goroutine migrated to a different thread during the call
injection this would result in two threads of the target process
pointing to the same TLS area which would greatly confuse the target
runtime, leading to fatal panics with nonsensical stack traces.
Other backends are unaffected:
- native/windows doesn't store the TLS in the same CONTEXT struct as
the other register values.
- native/darwin doesn't support function calls (and wouldn't store the
TLS value in the same struct)
- gdbserial/rr doesn't support function calls (because it's a
recording)
- gsdbserial/lldb extracts the value of TLS by executing code in the
target process.
Adds initial support for plugins, this is only the code needed to keep
track of loaded plugins on linux (both native and gdbserial backend).
It does not actually implement support for debugging plugins on linux.
Updates #865
The repository is being switched from the personal account
github.com/derekparker/delve to the organization account
github.com/go-delve/delve. This patch updates imports and docs, while
preserving things which should not be changed such as my name in the
CHANGELOG and in TODO comments.
If proc.Step encounters a CALL instruction that points to an address
that isn't associated with any function it should still follow the
CALL.
The circumstances creating this problem do not normally occur, it was
encountered in the process of fixing a bug created by Go1.12.
This patch is a slight refactor to share more code used for genericprocess initialization. There will always be OS/backend specificinitialization, but as much as can be shared should be to preventduplicating of any logic (setting internal breakpoints, loading bininfo,etc).
The linux version of proc/native and proc/core contained largely
overlapping implementations of the register handling code, deduplicate
it by moving it into proc/linutil.
Some libraries (for example steam_api64.dll) will send this exception
code to set the thread name on Microsoft VisualC.
In theory it should be fine to send the exception back to the target,
which is responsible for setting a handler for it, in practice in some
cases (steam_api64.dll) this will crash the program. So we'll mask it
instead.
Fixes#1383
Support for position independent executables (PIE) on the native linux
backend, the gdbserver backend on linux and the core backend.
Also implemented in the windows native backend, but it can't be tested
because go doesn't support PIE on windows yet.
On macOS 10.14 Apple changed the command line tools so that system
headers now need to be manually installed.
Instead of adding one extra install step to the install procedure add a
build tag to allow compilation of delve without the native backend on
macOS. By default (i.e. when using `go get`) this is how delve will be
compiled on macOS, the make script is changed to enable compiling the
native backend if the required dependencies have been installed.
Insure that both configuration still build correctly on Travis CI and
change the documentation to describe how to compile the native backend
and that it isn't normally needed.
Fixes#1359
Fncall.go was written with the assumption that the object returned by
proc.Thread.Registers does not change after we call
proc.Thread.SetPC/etc.
This is true for the native backend but not for gdbserial. I had
anticipated this problem and introduced the Save/SavedRegisters
mechanism during the first implementation of fncall.go but that's
insufficient.
Instead:
1. clarify that the object returned by proc.Thread.Registers could
change when the CPU registers are modified.
2. add a Copy method to Registers that returns a copy of the registers
that are guaranteed not to change when the CPU registers change.
3. remove the Save/SavedRegisters mechanism.
This solution leaves us the option, in the future, to cache the output
of proc.(Thread).Registers, avoiding a system call every time it's
called.
If we send a process to foreground while the headless instance may get
a SIGTTOU/SIGTTIN, if not ignored this signal will stop the headless.
It's not clear why this only happens the second time we do this but
that's how it is.
Also removes the direct syscall to TIOCSPGRP and lets the go runtime do
it instead.
Fixes#1279
Implements the function call injection protocol introduced in go 1.11
by https://go-review.googlesource.com/c/go/+/109699.
This is only the basic support, see TODO comments in pkg/proc/fncall.go
for a list of missing features.
Updates #119
