If we cannot find debug information locally on the system, try and
invoke debuginfod-find in order to ask the linux distribution we're on
to find the debug information for us.
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.
Adds a script that check automatically that the the assumptions that
pkg/proc makes about runtime are met by the actual runtime, using a
combination of parsing and magic comments.
Also emits a file describing all the struct fields, constants and
variables of the runtime that we use in pkg/proc.
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.
* proc: Go 1.18 removes the _defer.siz field
As of Go 1.17, the _defer.siz field is always 0 because _defer no
longer stores defer call arguments at all. golang.org/cl/326062
removes it entirely for Go 1.18. Simply treat it as 0 if the field is
missing from the _defer type.
* proc: Go 1.18 changes _defer.fn from *funcval to func()
golang.org/cl/325918 changed the type of the _defer.fn field from
*funcval to func() for Go 1.18. This CL was later reverted because it
caused failures in Delve, but we would like to un-revert it. Handle
this change by inspecting the type of this field before decoding it.
* pkg/proc: Prefer throw instead of fatalthrow
Currently there is a breakpoint set at runtime.fatalthrow to catch any
situation where the runtime crashes (e.g. deadlock).
When we do this, we go up a frame in order to parse the crash reason.
The problem is that there is no guarentee the "s" variable we attempt to
parse will still be considered "live".
Since runtime.fatalthrow is never called directly, set a breakpoint on
runtime.throw instead and prevent having
to search up a stack frame in order to
get the throw reason.
Fixes#2602
* service/dap: Fix TestFatalThrowBreakpoint
* Reenable TestFatalThrow DAP test
* service/dap: Don't skip test on < 1.17
* service/dap: Update test constraint for 1.16
* pkg/proc: Reinstate runtime.fatalthrow as switchstack exception
StaticBase is the difference between the entry point declared in the
image file and the entry point as loaded in memory, since this
difference could be a negative number we have to use a signed
comparison when searching for a mapping.
Causes intermittent test failures on windows when resolving interface
types for position independent executables.
Fixes#2620
Conversion form a moduledata object into an image object was
implemented by looking for a function covering the start address of the
text section of the moduledata object, and then converting that into
its corresponding image.
Unfortunately this seems to not always work. In particular it does not
work on linux/386 with go1.17 (but it might also fail on other
combinations): the start address of the text section is, for whatever
reason, not part of any function.
As a fallback simply scan all images we know of and return the closest
one that has start address less than or equal to the start address of
the text section we are looking for.
Fixes TestPluginVariables on go1.17/linux/386.
Fixes#2611
Co-authored-by: a <a@kra>
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
* 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>
ConvertEvalScope() attempts to find the scope for the specified
goroutine id and frame index. If the goroutine that is found is nil,
then it falls back to the threads stack trace to find the scope.
This fix makes sure that the frame id is taken into account for
thread strack traces as well.
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.
Adds filtering and grouping to the goroutines command.
The current implementation of the goroutines command is modeled after
the threads command of gdb. It works well for programs that have up to
a couple dozen goroutines but becomes unusable quickly after that.
This commit adds the ability to filter and group goroutines by several
different properties, allowing a better debugging experience on
programs that have hundreds or thousands of goroutines.
While Go still mostly uses DWARF v4, newer versions of GCC will emit
DWARF v5 by default. This patch improves support for DWARF v5 by parsing
the .debug_line_str section and using that during file:line lookups.
This patch only includes support for files, not directories.
Co-authored-by: Derek Parker <deparker@redhat.com>
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.
If the client supports paging, we allow them to fetch array and slice items in chunks that we assume will be of a reasonable size. For example, VS Code requests indexed variables in chunks of 100.
Fixesgolang/vscode-go#1518
If the base address isn't set then indexing and slicing will not work.
Large floating point registers already had the base set but small
general purpose registers did not.
* 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 code populating runtimeTypeToDIE was incorrectly adding StaticBase
to the offset. We never noticed because on statically compiled
executables StaticBase is always zero and on PIE and plugins the
fallback code took care of the problem anyway.
A change in Go 1.17 broke the fallback code, making the issue apparent.
This commit fixes the setup of runtimeTypeToDIE and disables the
fallback code for Go 1.17 and later.
This change also fixes a rare failure in TestPluginVariables when PIE
is enabled.
Truncates the result of binary operations on integers to the size of
the resulting type.
Also rewrites convertInt to not require allocations.
Fixes#2454
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.
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.
* service/dap: add type information to dap variables
* add comment explaining map type choice
* rename to setClientCapabilities
* respond to review
* update TypeString definition
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
Changes the expression evaluation code so that register names, when not
shadowed by local or global variables, will evaluate to the current
value of the corresponding CPU register.
This allows a greater flexibility with displaying CPU registers than is
possible with using the ListRegisters API call. Also it allows
debuggers users to view register values even if the frontend they are
using does not implement a register view.
