* 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.
1. Don't use intelligent '#' in fmt of go because it is not always satisfying
for diffrent version of golang. Always keep one leading zero for octal and
one leading '0x' for hex manually. Then keep alignment for every byte.
2. Always keep addr alignment when the lens of two adjacent address are
different.
Update #1814.
Adds an optional scope prefix to the `regs` command which allows
printing registers for any stack frame (as long as they were somehow
saved). Issue #1838 is not yet to be closed since we are still not
recovering the registers of a segfaulting frame.
Updates #1838
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
* Fixed DirIdx (index starts at one)
I am using the elf to load C++ based elf and there the index starts at one and not zero, hence the minor fix.
* Added test
* Added proper test for c-generated elf & replaced index offset by adding build dir
* Changed other IncludeDir test
* Format fix & replace print with actual test
* Format fixes @derekparker requested.
Go 1.8 has been out of date for a while and the code to support it is
potentially dangerous if a future version of Go removes the runtime
types from debug_info and also changes their representation.
Removes the restriction that the DWARF type for the receiver of a method
must be a TypeDef. This seems reasonable in practice, but it turns out
Go DWARF does not consider
```
type X int
```
to be a typedef. This patch also allows for calling a method where the
receiver is not used or passed in, such as:
```
func (_ X) Method() { println("why") }
```
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
Instead of reloading the registers for every thread every time the
process executes, reload the registers on demand for individual threads
and memoize the result.
According to #1800#1584#1038, `dlv` should enable the user to dive into
memory. User can print binary data in specific memory address range.
But not support for sepecific variable name or structures temporarily.(Because
I have no idea that modify `print` command.)
Close#1584.
The stacktrace code occasionally needs the value of g.m.g0.sched.sp to
switch stacks. Since this is only needed rarely and calling parseG is
relatively expensive we should delay doing it until we know it will be
needed.
Benchmark before:
BenchmarkConditionalBreakpoints-4 1 17326345671 ns/op
Benchmark after:
BenchmarkConditionalBreakpoints-4 1 15649407130 ns/op
Reduces conditional breakpoint latency from 1.7ms to 1.56ms.
Updates #1549
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
It was reading all the way to the end of the debug_info section,
slowing down stacktraces substantially.
Benchmark before:
BenchmarkConditionalBreakpoints-4 1 80344642562 ns/op
Benchmark after:
BenchmarkConditionalBreakpoints-4 1 22218288218 ns/op
i.e. a reduction of the cost of a breakpoint hit from 8ms to 2.2ms
Updates #1549
* 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
* 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>
Expression such as:
config show-location-expr true
disassemble -a 0x4a23a0 0x4a23f2
disassemble -a 0x4a23a0 0x4a23f2
should all execute correctly.
Extend #795.
Adds a cache mapping goroutine IDs to goroutine objects, this allows
speeding up FindGoroutine and makes commands like 'goroutines -t' not
be accidentally quadratic in the number of goroutines.
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
Due to a bug in the Go compiler midstack inlined calls do not report
their ranges correctly. We can't check if an address is in the range of
a DIE by simply looking at that DIE's range, we should also recursively
check the DIE's children's ranges.
Also fixes the way stacktraces of midstack inlined calls are reported
(they used to be inverted, with the deepest inlined stack frame
reported last).
Fixes#1795
Adds an API call that returns a list of packages contained in the
program and the files that were used to build them, and also a best
guess at which filesystem directory contained the package when it was
built.
This can be used by IDEs to map file paths if the debugging environment
doesn't match the build environment exactly.
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).
Remove build tags from disassembler code, move architecture specific
functionality inside proc.Arch.
This is necessary because Delve should be able to debug corefiles
cross-platform.
During a debug session if the process exited and then the user quit the
debug session, the process exit message would display again and Delve
would exit non-zero (specifically with exit code 1) despite nothing
going wrong.
This patch fixes this so that Delve exits with a clean 0 status and the
process exit message is not printed yet again.
* fix TestKill test:
It will fail in Open /proc/pid/ sporadicly since there is no any sync between signal sended(tracee handled) and open /proc/%d/, especially in some weak arm64 cpu. Skip /proc check on arm64.
* remove skip-code of Detach tests.
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.
PtraceSingleStep cannot step over BRK instruction(linux-arm64 feature or kernel bug maybe).
GDB has the same question too, it will hang on forever with c command or execute that instruction indefinitely with s,si command.
SetPC+BreakpointSize to jump over BRK to prevent repeating the instruction indefinitely.
Co-authored-by: tykcd996 <tang.yuke@zte.com.cn>
Co-authored-by: hengwu0 <wu.heng@zte.com.cn>
* 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)
Use the name specified by compile unit attribute DW_AT_go_package_name,
introduced in Go 1.13, to map package names to package paths, instead of
trying to deduce it from names of types.
Also use this mapping for resolving global variables and function
expressions.
* 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.
* proc/core: enable PIE tests
PIE tests for core files were never enabled due to a missing flag.Parse
call.
* 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.
Instead of just sending unhandled signals back to the process send them
to the specific thread that received them.
This is important because:
1. debugserver does not appear to support the vCont;CXX packet without
specifying a target thread
2. the non-cooperative preemption change in an upcoming version of Go
(1.15?) will require sending signals to a specific thread.
Fixes#1744
Changes CreateBreakpoint to create a logical breakpoint when multiple
addresses are specified, FindLocation and the api.Location type to
return logical locations and the cli to support logical breakpoints.
Modifies FindFileLocation, FindFunctionLocation and LineToPC as well as
service/debugger to support inlining and introduces the concept of
logical breakpoints.
For inlined functions FindFileLocation, FindFunctionLocation and
LineToPC will now return one PC address for each inlining and one PC
for the concrete implementation of the function (if present).
A proc.Breakpoint will continue to represent a physical breakpoint, at
a single memory location.
Breakpoints returned by service/debugger, however, will represent
logical breakpoints and may be associated with multiple memory
locations and, therefore, multiple proc.Breakpoints.
The necessary logic is introduced in service/debugger so that a change
to a logical breakpoint will be mirrored to all its physical
breakpoints and physical breakpoints are aggregated into a single
logical breakpoint when returned.
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
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).
Make the 'list' command succeed for file:line expressions that don't
map to any instruction.
Adds an argument to the FindLocations API call that makes FindLocations
return if the expression can be parsed, even if it doesn't end up
matching any instruction in debug_line.
Adds a '-r' option to the 'restart' command (and to the Restart API)
that re-records the target when using rr.
Also moves the code to delete the trace directory inside the gdbserial
package.
A compile unit can produce a debug_line program consisting of multiple
sequences according to the DWARF standard. The standard guarantees that
addresses monotonically increment within a single sequence but
different sequences may not follow this rule.
This commit changes dwarf/line (in particular PCToLine and
AllPCsBetween) to support debug_line sections containing units with
multiple sequences.
TestPCToLine needs to be changed so that it picks valid addresses (i.e.
addresses covered by a sequence) as values for basePC, instead of just
rounding.
Fixes#1694
Splits the code that loads function information from debug_info into
multiple functions.
This makes the changes needed to implement logical breakpoints easier
to make.
Trust argument order to determine argument frame layout when calling
functions, this allows calling optimized functions and removes the
special cases for runtime.mallocgc.
Fixes#1589
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
According to the description of "CIE: length, CIE_id, version, augmentation"
in Page 122 of http://dwarfstd.org/doc/Dwarf3.pdf ,
`augmentation` should exclude `version`
The fix for #1428 was buggy, partly because I communicated poorly. Sorry
about that.
The size of the TLS segment should be padded such that TLS addresses
are congruent in the file to where they will end up memory, i.e.
(tlsoffset%align) == (vaddr%align). In most cases, vaddr will be aligned
and it won't matter, but if not then simply aligning the end of the
segment is incorrect. This should be right.
(For the record, the current rounding logic is working in bits, but
PtrSize is in bytes, so it wasn't working as originally intended
either.)
