* proc: correctly update local variables after continue
At various point during the execution of the call injection protocol
the process is resumed and the call injection goroutine could migrate
to a different thread, we must make sure to update our local variables
correctly after every point where the target program is resumed.
'fncall122debug_clean' on 'f469a0a5'.
* go.mod: update golang.org/x/tools
Go 1.22 broke golang.org/x/tools/packages
* cmd/dlv: disable TestStaticcheck with go1.22
Go 1.22 is not yet supported by staticcheck.
If there is no current goroutine when 'next', 'step' or 'stepout' are
used set a condition that the thread ID should stay the same instead.
This makes stepping work for multithreaded C programs or Go programs
that have threads started by cgo code.
Fixes#3262
* logflags,proc: flag to log stacktrace execution
Add a log flag to write logs about what the stacktracer does.
* proc: read context from sigtrampgo, fixes TestCgoStacktrace2 on 1.21
Changes stacktrace code to read the signal context from the arguments
of sigtrampgo.
Also changes the automatic fatalthrow breakpoint for go 1.21.
In combination these two changes fix TestCgoStacktrace2 on Go 1.21 on
various platforms.
We used to parse the .gopclntab section but removed support in favor of
simply using DWARF debug information, due to lack of C symbols among
other reasons. This makes it impossible to debug stripped binaries,
which some distrubutions ship by default.
Add back in basic support for .gopclntab which survives if the binary
is stripped, allowing for rudimentary debugging such as basic
program navigation, tracing, etc...
When using Step on a function that has a dynamic CALL instruction we
set a Step breakpoint on the call.
When it is hit we determine the destination of the CALL by looking at
registers, set a breakpoint there and continue.
If the Step breakpoint is hit simultaneously with a normal breakpoint
our Step logic will take precedence and the normal breakpoint hit will
be hidden from the user.
Move the Step logic to a breaklet callback so that it does not
interfere with the decision to stop.
Adds the ability to automatically debug child processes executed by the
target to the linux native backend.
This commit does not contain user interface or API to access this
functionality.
Updates #2551
Introduces a new TargetGroup abstraction that can be used to manage
multiple related targets.
No actual management of child processes is implemented here, this is
just a refactoring to make it possible to do that in the future.
Updates #2551
Go 1.19 also formats doc comments according to the new godoc syntax.
Some of our comments, especially unexported symbols did not conform to
the godoc syntax and therefore are mangled by 'go fmt'.
This PR runs 'go fmt' from go1.19 on everything and manually fixes the
problems.
See also:
https://github.com/golang/proposal/blob/master/design/51082-godocfmt.md
Adds a LogicalBreakpoint type to represent logical breakpoints
explicitly. Until now logical breakpoints were constructed implicitly
by grouping physical breakpoints together by their LogicalID.
Having logical breakpoints represented explicitly allows for a simpler
implementation of disabled breakpoints, as well as allowing a simple
implementation of delayed breakpoints (#1653, #2551) and in general of
breakpoints spanning multiple processes if we implement debugging
process trees (#2551).
Updates #1653
Updates #2551
The fix in #2959 was incomplete and the skip was still broken on
linux/386 for PIE builds due to calls to the get_pc_thunk helper.
Co-authored-by: a <a@kra>
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.
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
Go 1.18 removed the jmpdefer call from deferreturn, now deferreturn is
a normal function call that can appear on the stack, rules for
detecting a deferreturn call must be changed and new code must be added
to skip it while stepping out.
In order for DAP to support halting the program (either manually or on a breakpoint) performing some action and then resuming execution, there needs to be a way to stop the program without clearing the internal breakpoints. This is necessary for log points and stopping the program to set breakpoints.
The debugging UI makes it seem like a user should be able to set or clear a breakpoint at any time. Adding this ability to complete synchronous requests while the program is running is thus important to create a seamless user experience.
This change just adds a configuration to determine whether the target should clear the stepping breakpoints, and changes the server to use this new mode. Using the new mode means that the DAP server must determine when it expect the next to be canceled and do this manually.
* terminal,service: add way to see internal breakpoints
Now that Delve has internal breakpoints that survive for long periods
of time it will be useful to have an option to display them.
* proc,terminal,service: support stack watchpoints
Adds support for watchpoints on stack allocated variables.
When a stack variable is watched, in addition to the normal watchpoint
some support breakpoints are created:
- one breakpoint inside runtime.copystack, used to adjust the address
of the watchpoint when the stack is resized
- one or more breakpoints used to detect when the stack variable goes
out of scope, those are similar to the breakpoints set by StepOut.
Implements #279
* 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
* proc: support new Go 1.17 panic/defer mechanism
Go 1.17 will create wrappers for deferred calls that take arguments.
Change defer reading code so that wrappers are automatically unwrapped.
Also the deferred function is called directly by runtime.gopanic, without going through runtime.callN which means that sometimes when a panic happens the stack is either:
0. deferred function call
1. deferred call wrapper
2. runtime.gopanic
or:
0. deferred function call
1. runtime.gopanic
instead of always being:
0. deferred function call
1. runtime.callN
2. runtime.gopanic
the isPanicCall check is changed accordingly.
* test: miscellaneous minor test fixes for Go 1.17
* proc: resolve inlined calls when stepping out of runtime.breakpoint
Calls to runtime.Breakpoint are inlined in Go 1.17 when inlining is
enabled, resolve inlined calls in stepInstructionOut.
* proc: add support for debugCallV2 with regabi
This change adds support for the new debug call protocol which had to
change for the new register ABI introduced in Go 1.17.
Summary of changes:
- Abstracts over the debug call version depending on the Go version
found in the binary.
- Uses R12 instead of RAX as the debug protocol register when the binary
is from Go 1.17 or later.
- Creates a variable directly from the DWARF entry for function
arguments to support passing arguments however the ABI expects.
- Computes a very conservative stack frame size for the call when
injecting a call into a Go process whose version is >=1.17.
Co-authored-by: Michael Anthony Knyszek <mknyszek@google.com>
Co-authored-by: Alessandro Arzilli <alessandro.arzilli@gmail.com>
* TeamCity: enable tests on go-tip
* goversion: version compatibility bump
* TeamCity: fix go-tip builds on macOS/arm64
Co-authored-by: Michael Anthony Knyszek <mknyszek@google.com>
We told clients that further loading of variables can be done by
specifying a type cast using the address of a variable that we
returned.
This does not work for registerized variables (or, in general,
variables that have a complex location expression) because we don't
give them unique addresses and we throw away the compositeMemory object
we made to read them.
This commit changes proc so that:
1. variables with location expression divided in pieces do get a unique
memory address
2. the compositeMemory object is saved somewhere
3. when an integer is cast back into a pointer type we look through our
saved compositeMemory objects to see if there is one that covers the
specified address and use it.
The unique memory addresses we generate have the MSB set to 1, as
specified by the Intel 86x64 manual addresses in this form are reserved
for kernel memory (which we can not read anyway) so we are guaranteed
to never generate a fake memory address that overlaps a real memory
address of the application.
The unfortunate side effect of this is that it will break clients that
do not deserialize the address to a 64bit integer. This practice is
contrary to how we defined our types and contrary to the specification
of the JSON format, as of json.org, however it is also fairly common,
due to javascript itself having only 53bit integers.
We could come up with a new mechanism but then even more old clients
would have to be changed.
Ensure that any command executed after the process we are trying to
debug prints a correct and consistent exit status.
Previously the exit code was being lost after the first time we printed
that a process has exited. Additionally, certain commands would print
the PID of the process and other would not. This change makes everything
more correct and consistent.
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
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.
Adds a flag that distinguishes the return values of an injected
function call from the return values of a function call executed by the
target program.
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
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.
An internal breakpoint condition shouldn't ever error:
* use a ThreadContext to evaluate conditions if a goroutine isn't
available
* evaluate runtime.curg to a fake g variable containing only
`goid == 0` when there is no current goroutine
Fixes#2113
* proc: start variable visibility one line after their decl line
In most cases variables shouldn't be visible on their declaration line
because they won't be initialized there.
Function arguments are treated as an exception.
This fix is only applied to programs compiled with Go 1.15 or later as
previous versions of Go did not report the correct declaration line for
variables captured by closures.
Fixes#1134
* proc: silence go vet error
* Makefile: enable PIE tests on windows/Go 1.15
* core: support core files for PIEs on windows
* goversion: add Go 1.15 to supported versions
* proc: fix function call injection for Go 1.15
Go 1.15 changed the call injection protocol so that the runtime will
execute the injected call on a different (new) goroutine.
This commit changes the function call support in delve to:
1. correctly track down the call injection state after the runtime
switches to a different goroutine.
2. correctly perform the escapeCheck when stack values can come from
multiple goroutine stacks.
* proc: miscellaneous fixed for call injection under macOS with go 1.15
- create copy of SP in debugCallAXCompleteCall case because the code
used to assume that regs doesn't change
- fix automatic address calculation for function arguments when an
argument has a spurious DW_OP_piece at entry
The file:line information for the entrypoint is more acccurate than the
file:line information at a return point, which could be affected by a
compiler bug.
Fixes#2086
On platforms other than macOS this doesn't matter but on macOS a
segmentation fault will cause ContinueOnce to return an error, before
returning it we should still fix the current thread and selected
goroutine values.
Fixes#2078
Normally we don't step into unexported runtime functions because the
compiler is free to insert them into the code and they are not relevant
to the user, however if we are already stepping through a runtime
function we should let step into work normally and step into other
runtime functions.
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
Under some circumstances (methods with non-pointer receivers or from
embedded fields called through an interface) the compiler will
autogenerate wrapper functions.
This commit changes next, step and stepout to skip all autogenerated
wrappers.
Fixes#1908
