packages
Changes UserCurrent to exclude frames stopped inside the 'internal' and
'runtime/internal' packages of the standard library.
Before this change a goroutine blocked accepting or reading from a
socket would be reported as having a user current frame of:
internal/poll.runtime_pollWait
After this change accepting goroutines will be reported with a user
current frame of:
net.(*netFD).accept
and reading goroutines as:
net.(*netFD).read
Change debug_info type reader and proc to convert parametric types into
their real types by reading the corresponding dictionary entry and
using the same method used for interfaces to retrieve the DIE from a
runtime._type address.
'2586e9b1'.
* pkg/proc: update check for system goroutine
The finalizer goroutine can be either a system goroutine or a user goroutine. It is considered a user goroutine only when it calls back to user code. This change attempts to get closer to the implementation in the src/runtime/traceback.go by checking the value of fingRunning.
We could alternatively adopt the approximation done by src/cmd/trace/trace.go which only special cases "runtime.main", and always considers the finalizer to be a system goroutine.
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.
* 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: 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.
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.
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.
* service/dap: add type information to dap variables
* add comment explaining map type choice
* rename to setClientCapabilities
* respond to review
* update TypeString definition
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.
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.
Both structMember and findMethod implemented a depth-first search in
embedded fields but the Go specification requires a breadth-first
search. They also allowed promotion of fields in the concrete type of
embedded interfaces even though this is not allowed by Go.
Furthermore they both lacked protection from infinite recursion
when a type embeds itself and the user requests a non-existent field.
Fixes#2316
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
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
Instead of rescanning debug_info every time we want to read a function
(either to find inlined calls or its variables) cache the tree of
dwarf.Entry that we would generate and use that.
Benchmark before:
BenchmarkConditionalBreakpoints-4 1 5164689165 ns/op
Benchmark after:
BenchmarkConditionalBreakpoints-4 1 4817425836 ns/op
Updates #1549
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
runtime.g is a large and growing struct, we only need a few fields.
Instead of using loadValue to load the full contents of g, cache its
memory and then only load the fields we care about.
Benchmark before:
BenchmarkConditionalBreakpoints-4 1 14586710018 ns/op
Benchmark after:
BenchmarkConditionalBreakpoints-4 1 12476166303 ns/op
Conditional breakpoint evaluation: 1.45ms -> 1.24ms
Updates #1549
* proc: separate amd64-arch code
separate amd64 code about stacktrace, so we can add arm64 stacktrace code.
* proc: implemente stacktrace of arm64
* delve now can use stack, frame commands on arm64-arch debug.
Co-authored-by: tykcd996 <tang.yuke@zte.com.cn>
Co-authored-by: hengwu0 <wu.heng@zte.com.cn>
* test: remove skip-code of stacktrace on arm64
* add LR DWARF register and remove skip-code for fixed tests
* proc: fix the Continue command after the hardcoded breakpoint on arm64
Arm64 use hardware breakpoint, and it will not set PC to the next instruction like amd64. We should move PC in both runtime.breakpoints and hardcoded breakpoints(probably cgo).
* proc: implement cgo stacktrace on arm64
* proc: combine amd64_stack.go and arm64_stack.go file
* proc: reorganize the stacktrace code
* move SwitchStack function arch-related
* fix Continue command after manual stop on arm64
* add timeout flag to make.go to enable infinite timeouts
Co-authored-by: aarzilli <alessandro.arzilli@gmail.com>
Co-authored-by: hengwu0 <wu.heng@zte.com.cn>
Co-authored-by: tykcd996 <56993522+tykcd996@users.noreply.github.com>
Co-authored-by: Alessandro Arzilli <alessandro.arzilli@gmail.com>
program
When evaluating type casts always resolve array types.
Instead of resolving them by looking up the string in debug_info
construct a fake array type so that a type cast to an array type always
works as long as the element type exists.
We already did this for byte arrays, this commit extends this to any
array type. The reason is that we return a fake array type (that
doesn't exist in the target program) for the array of a channel type.
Fixes#1736
Add options to start a stacktrace from the values saved in the
runtime.g struct as well as a way to disable the stackSwitch logic and
just get a normal stacktrace.
If a closure captures a variable but also defines a variable of the
same name in its root scope the shadowed flag would, sometimes, not be
appropriately applied to the captured variable.
This change:
1. sorts the variable list by depth *and* declaration line, so that
closure captured variables always appear before other root-scope
variables, regardless of the order used by the compiler
2. marks variable with the same name as shadowed even if there is only
one scope at play.
This fixes the problem but as a side effect:
1. programs compiled with Go prior to version 1.9 will have the
shadowed flag applied arbitrarily (previously the shadowed flag was not
applied at all)
2. programs compiled with Go prior to versoin 1.11 will still exhibit
the bug, as they do not have DeclLine information.
Fixes#1672
Moves EvalScope methods to the proper file and organizes everything
together. Also makes some EvalScope methods no longer methods and just
pure functions.
Add variables flag to mark variables that are allocated on a register
(and have no address) and variables that we read as result of a
function call (and are allocated on a stack that no longer exists when
we show them to the user).
