Moving these intrinsics to a base package enables other internal/runtime
packages to use them.
For #54766.
Change-Id: I45a530422207dd94b5ad4eee51216c9410a84040
Reviewed-on: https://go-review.googlesource.com/c/go/+/613261
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Moving these intrinsics to a base package enables other internal/runtime
packages to use them.
For #54766.
Change-Id: I0b3eded3bb45af53e3eb5bab93e3792e6a8beb46
Reviewed-on: https://go-review.googlesource.com/c/go/+/613260
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Currently, the execution tracer may attempt to take a stack trace of a
goroutine whose stack it does not own. For example, if the goroutine is
in _Grunnable or _Gwaiting. This is easily fixed in all cases by simply
moving the emission of GoStop and GoBlock events to before the
casgstatus happens. The goroutine status is what is used to signal stack
ownership, and the GC may shrink a goroutine's stack if it can acquire
the scan bit.
Although this is easily fixed, the interaction here is very subtle,
because stack ownership is only implicit in the goroutine's scan status.
To make this invariant more maintainable and less error-prone in the
future, this change adds a GODEBUG setting that checks, at the point of
taking a stack trace, whether the caller owns the goroutine. This check
is not quite perfect because there's no way for the stack tracing code
to know that the _Gscan bit was acquired by the caller, so for
simplicity it assumes that it was the caller that acquired the scan bit.
In all other cases however, we can check for ownership precisely. At the
very least, this check is sufficient to catch the issue this change is
fixing.
To make sure this debug check doesn't bitrot, it's always enabled during
trace testing. This new mode has actually caught a few other issues
already, so this change fixes them.
One issue that this debug mode caught was that it's not safe to take a
stack trace of a _Gwaiting goroutine that's being unparked.
Another much bigger issue this debug mode caught was the fact that the
execution tracer could try to take a stack trace of a G that was in
_Gwaiting solely to avoid a deadlock in the GC. The execution tracer
already has a partial list of these cases since they're modeled as the
goroutine just executing as normal in the tracer, but this change takes
the list and makes it more formal. In this specific case, we now prevent
the GC from shrinking the stacks of goroutines in this state if tracing
is enabled. The stack traces from these scenarios are too useful to
discard, but there is indeed a race here between the tracer and any
attempt to shrink the stack by the GC.
Change-Id: I019850dabc8cede202fd6dcc0a4b1f16764209fb
Cq-Include-Trybots: luci.golang.try:gotip-linux-amd64-longtest,gotip-linux-amd64-longtest-race
Reviewed-on: https://go-review.googlesource.com/c/go/+/573155
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
This change resolves a TODO in the coroutine switch implementation (used
exclusively by iter.Pull at the moment) to enable tracing. This was
blocked on eliminating the atomic load in the tracer's "off" path
(completed in the previous CL in this series) and the addition of new
tracer events to minimize the overhead of tracing in this circumstance.
This change introduces 3 new event types to support coroutine switches:
GoCreateBlocked, GoSwitch, and GoSwitchDestroy.
GoCreateBlocked needs to be introduced because the goroutine created for
the coroutine starts out in a blocked state. There's no way to represent
this in the tracer right now, so we need a new event for it.
GoSwitch represents the actual coroutine switch, which conceptually
consists of a GoUnblock, a GoBlock, and a GoStart event in series
(unblocking the next goroutine to run, blocking the current goroutine,
and then starting the next goroutine to run).
GoSwitchDestroy is closely related to GoSwitch, implementing the same
semantics except that GoBlock is replaced with GoDestroy. This is used
when exiting the coroutine.
The implementation of all this is fairly straightforward, and the trace
parser simply translates GoSwitch* into the three constituent events.
Because GoSwitch and GoSwitchDestroy imply a GoUnblock and a GoStart,
they need to synchronize with other past and future GoStart events to
create a correct partial ordering in the trace. Therefore, these events
need a sequence number for the goroutine that will be unblocked and
started.
Also, while implementing this, I noticed that the coroutine
implementation is actually buggy with respect to LockOSThread. In fact,
it blatantly disregards its invariants without an explicit panic. While
such a case is likely to be rare (and inefficient!) we should decide how
iter.Pull behaves with respect to runtime.LockOSThread.
Lastly, this change also bumps the trace version from Go 1.22 to Go
1.23. We're adding events that are incompatible with a Go 1.22 parser,
but Go 1.22 traces are all valid Go 1.23 traces, so the newer parser
supports both (and the CL otherwise updates the Go 1.22 definitions of
events and such). We may want to reconsider the structure and naming of
some of these packages though; it could quickly get confusing.
For #61897.
Change-Id: I96897a46d5852c02691cde9f957dc6c13ef4d8e7
Reviewed-on: https://go-review.googlesource.com/c/go/+/565937
Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Currently the execution tracer synchronizes with itself using very
heavyweight operations. As a result, it's totally fine for most of the
tracer code to look like:
if traceEnabled() {
traceXXX(...)
}
However, if we want to make that synchronization more lightweight (as
issue #60773 proposes), then this is insufficient. In particular, we
need to make sure the tracer can't observe an inconsistency between g
atomicstatus and the event that would be emitted for a particular
g transition. This means making the g status change appear to happen
atomically with the corresponding trace event being written out from the
perspective of the tracer.
This requires a change in API to something more like a lock. While we're
here, we might as well make sure that trace events can *only* be emitted
while this lock is held. This change introduces such an API:
traceAcquire, which returns a value that can emit events, and
traceRelease, which requires the value that was returned by
traceAcquire. In practice, this won't be a real lock, it'll be more like
a seqlock.
For the current tracer, this API is completely overkill and the value
returned by traceAcquire basically just checks trace.enabled. But it's
necessary for the tracer described in #60773 and we can implement that
more cleanly if we do this refactoring now instead of later.
For #60773.
Change-Id: Ibb9ff5958376339fafc2b5180aef65cf2ba18646
Reviewed-on: https://go-review.googlesource.com/c/go/+/515635
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
This CL adds support for debugger function calls on linux ppc64le
platform. The protocol is basically the same as in CL 395754, except for
the following differences:
1, The abi differences which affect parameter passing and frame layout.
2, The closure register is R11.
3, Minimum framesize on pp64le is 32 bytes
4, Added functions to return parent context structure for general purpose
registers in order to work with the way these structures are defined in
ppc64le
Change-Id: I58e01fedad66a818ab322e2b2d8f5104cfa64f39
Reviewed-on: https://go-review.googlesource.com/c/go/+/512575
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Archana Ravindar <aravinda@redhat.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Right now debuggers like Delve rely on the new goroutine created to run
a debugcall function to run on the same thread it started on, up until
it hits itself with a SIGINT as part of the debugcall protocol.
That's all well and good, except debugCallWrap1 isn't particularly
careful about not growing the stack. For example, if the new goroutine
happens to have a stale preempt flag, then it's possible a stack growth
will cause a roundtrip into the scheduler, possibly causing the
goroutine to switch to another thread.
Previous attempts to just be more careful around debugCallWrap1 were
helpful, but insufficient. This change takes everything a step further
and always locks the debug call goroutine and the new goroutine it
creates to the OS thread.
For #61732.
Change-Id: I038f3a4df30072833e27e6a5a1ec01806a32891f
Reviewed-on: https://go-review.googlesource.com/c/go/+/515637
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Alessandro Arzilli <alessandro.arzilli@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Now that pcvalue keeps its cache on the M, we can drop all of the
stack-allocated pcvalueCaches and stop carefully passing them around
between lots of operations. This significantly simplifies a fair
amount of code and makes several structures smaller.
This series of changes has no statistically significant effect on any
runtime Stack benchmarks.
I also experimented with making the cache larger, now that the impact
is limited to the M struct, but wasn't able to measure any
improvements.
This is a re-roll of CL 515277
Change-Id: Ia27529302f81c1c92fb9c3a7474739eca80bfca1
Reviewed-on: https://go-review.googlesource.com/c/go/+/520064
Auto-Submit: Austin Clements <austin@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
Now that pcvalue keeps its cache on the M, we can drop all of the
stack-allocated pcvalueCaches and stop carefully passing them around
between lots of operations. This significantly simplifies a fair
amount of code and makes several structures smaller.
This series of changes has no statistically significant effect on any
runtime Stack benchmarks.
I also experimented with making the cache larger, now that the impact
is limited to the M struct, but wasn't able to measure any
improvements.
Change-Id: I4719ebf347c7150a05e887e75a238e23647c20cd
Reviewed-on: https://go-review.googlesource.com/c/go/+/515277
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Austin Clements <austin@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
This change adds traceBlockReason which leaks fewer implementation
details of the tracer to the runtime. Currently, gopark is called with
an explicit trace event, but this leaks details about trace internals
throughout the runtime.
This change will make it easier to change out the trace implementation.
Change-Id: Id633e1704d2c8838c6abd1214d9695537c4ac7db
Reviewed-on: https://go-review.googlesource.com/c/go/+/494185
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
We also rename the constants related to unsafe-points: currently, they
follow the same naming scheme as the PCDATA table indexes, but are not
PCDATA table indexes.
For #59670.
Change-Id: I06529fecfae535be5fe7d9ac56c886b9106c74fd
Reviewed-on: https://go-review.googlesource.com/c/go/+/485497
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Austin Clements <austin@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Currently, wait reasons are set somewhat inconsistently. In a follow-up
CL, we're going to want to rely on the wait reason being there for
casgstatus, so the status quo isn't really going to work for that. Plus
this inconsistency means there are a whole bunch of cases where we could
be more specific about the G's status but aren't.
So, this change adds a new function, casGToWaiting which is like
casgstatus but also sets the wait reason. The goal is that by using this
API it'll be harder to forget to set a wait reason (or the lack thereof
will at least be explicit). This change then updates all casgstatus(gp,
..., _Gwaiting) calls to casGToWaiting(gp, ..., waitReasonX) instead.
For a number of these cases, we're missing a wait reason, and it
wouldn't hurt to add a wait reason for them, so this change also adds
those wait reasons.
For #49881.
Change-Id: Ia95e06ecb74ed17bb7bb94f1a362ebfe6bec1518
Reviewed-on: https://go-review.googlesource.com/c/go/+/427617
Reviewed-by: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
This CL adds support for debugger function calls on linux arm64
platform. The protocol is basically the same as in CL 109699, except for
the following differences:
1, The abi difference which affect parameter passing and frame layout.
2, Stores communication information in R20.
3, The closure register is R26.
4, Use BRK 0 instruction to generate a breakpoint. The saved PC in
sigcontext is the PC where the signal occurred, not the next PC.
In addition, this CL refactors the existing code (which is dedicated to
amd64) for easier multi-arch scaling.
Fixes#50614
Change-Id: I06b14e345cc89aab175f4a5f2287b765da85a86b
Reviewed-on: https://go-review.googlesource.com/c/go/+/395754
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Eric Fang <eric.fang@arm.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
And then revert the bootstrap cmd directories and certain testdata.
And adjust tests as needed.
Not reverting the changes in std that are bootstrapped,
because some of those changes would appear in API docs,
and we want to use any consistently.
Instead, rewrite 'any' to 'interface{}' in cmd/dist for those directories
when preparing the bootstrap copy.
A few files changed as a result of running gofmt -w
not because of interface{} -> any but because they
hadn't been updated for the new //go:build lines.
Fixes#49884.
Change-Id: Ie8045cba995f65bd79c694ec77a1b3d1fe01bb09
Reviewed-on: https://go-review.googlesource.com/c/go/+/368254
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
When these packages are released as part of Go 1.18,
Go 1.16 will no longer be supported, so we can remove
the +build tags in these files.
Ran go fix -fix=buildtag std cmd and then reverted the bootstrapDirs
as defined in src/cmd/dist/buildtool.go, which need to continue
to build with Go 1.4 for now.
Also reverted src/vendor and src/cmd/vendor, which will need
to be updated in their own repos first.
Manual changes in runtime/pprof/mprof_test.go to adjust line numbers.
For #41184.
Change-Id: Ic0f93f7091295b6abc76ed5cd6e6746e1280861e
Reviewed-on: https://go-review.googlesource.com/c/go/+/344955
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
A subsequent change will alter the semantics of _func.entry.
To make that change obvious and clear, change _func.entry to a method,
and rename the field to _func.entryPC.
Change-Id: I05d66b54d06c5956d4537b0729ddf4290c3e2635
Reviewed-on: https://go-review.googlesource.com/c/go/+/351460
Trust: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
newproc/deferproc takes a siz argument for the go'd/deferred
function's argument size. Now it is always zero. Remove the
argument.
Change-Id: If1bb8d427e34015ccec0ba10dbccaae96757fa8c
Reviewed-on: https://go-review.googlesource.com/c/go/+/325917
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
The debug call tests currently assume that the target Go function is
ABI0; this is clearly no longer true when we switch to the new ABI, so
make the tests set up argument register state in the debug call handler
and copy back results returned in registers.
A small snag in calling a Go function that follows the new ABI is that
the debug call protocol depends on the AX register being set to a
specific value as it bounces in and out of the handler, but this
register is part of the new register ABI, so results end up being
clobbered. Use R12 instead.
Next, the new desugaring behavior for "go" statements means that
newosproc1 must always call a function with no frame; if it takes any
arguments, it closes over them and they're passed in the context
register. Currently when debugCallWrap creates a new goroutine, it uses
newosproc1 directly and passes a non-zero-sized frame, so that needs to
be updated. To fix this, briefly use the g's param field which is
otherwise only used for channels to pass an explicitly allocated object
containing the "closed over" variables. While we could manually do the
desugaring ourselves (we cannot do so automatically because the Go
compiler prevents heap-allocated closures in the runtime), that bakes in
more ABI details in a place that really doesn't need to care about them.
Finally, there's an old bug here where the context register was set up
in CX, so technically closure calls never worked. Oops. It was otherwise
harmless for other types of calls before, but now CX is an argument
register, so now that interferes with regular calls, too.
For #40724.
Change-Id: I652c25ed56a25741bb04c24cfb603063c099edde
Reviewed-on: https://go-review.googlesource.com/c/go/+/309169
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Alessandro Arzilli <alessandro.arzilli@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Make all our package sources use Go 1.17 gofmt format
(adding //go:build lines).
Part of //go:build change (#41184).
See https://golang.org/design/draft-gobuild
Change-Id: Ia0534360e4957e58cd9a18429c39d0e32a6addb4
Reviewed-on: https://go-review.googlesource.com/c/go/+/294430
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Make them always true. Delete code that are only executed when
they are false.
Change-Id: I6194fa00de23486c2b0a0c9075fe3a09d9c52762
Reviewed-on: https://go-review.googlesource.com/c/go/+/264339
Trust: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Austin Clements <austin@google.com>
CL 236857 removed all uses of whitelist/blacklist, which is great.
But it substituted awkward phrasing using allowlist/blocklist,
especially as verbs or participles. This CL uses more standard English,
like "allow the function" or "blocked functions" instead of
"allowlist the function" or "blocklisted functions".
Change-Id: I9106a2fdbd62751c4cbda3a77181358a8a6d0f13
Reviewed-on: https://go-review.googlesource.com/c/go/+/236917
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
There's been plenty of discussion on the usage of these terms in tech.
I'm not trying to have yet another debate. It's clear that there are
people who are hurt by them and who are made to feel unwelcome by their
use due not to technical reasons but to their historical and social
context. That's simply enough reason to replace them.
Anyway, allowlist and blocklist are more self-explanatory than whitelist
and blacklist, so this change has negative cost.
Didn't change vendored, bundled, and minified files. Nearly all changes
are tests or comments, with a couple renames in cmd/link and cmd/oldlink
which are extremely safe. This should be fine to land during the freeze
without even asking for an exception.
Change-Id: I8fc54a3c8f9cc1973b710bbb9558a9e45810b896
Reviewed-on: https://go-review.googlesource.com/c/go/+/236857
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Khosrow Moossavi <khos2ow@gmail.com>
Reviewed-by: Leigh McCulloch <leighmcc@gmail.com>
Reviewed-by: Urban Ishimwe <urbainishimwe@gmail.com>
Currently, we emit stack maps and register maps at almost every
instruction. This was originally intended to support non-cooperative
preemption, but was only ever used for debug call injection. Now debug
call injection also uses conservative frame scanning. As a result,
stack maps are only needed at call sites and register maps aren't
needed at all except that we happen to also encode unsafe-point
information in the register map PCDATA stream.
This CL reduces stack maps to only appear at calls, and replace full
register maps with just safe/unsafe-point information.
This is all protected by the go115ReduceLiveness feature flag, which
is defined in both runtime and cmd/compile.
This CL significantly reduces binary sizes and also speeds up compiles
and links:
name old exe-bytes new exe-bytes delta
BinGoSize 15.0MB ± 0% 14.1MB ± 0% -5.72%
name old pcln-bytes new pcln-bytes delta
BinGoSize 3.14MB ± 0% 2.48MB ± 0% -21.08%
name old time/op new time/op delta
Template 178ms ± 7% 172ms ±14% -3.59% (p=0.005 n=19+19)
Unicode 71.0ms ±12% 69.8ms ±10% ~ (p=0.126 n=18+18)
GoTypes 655ms ± 8% 615ms ± 8% -6.11% (p=0.000 n=19+19)
Compiler 3.27s ± 6% 3.15s ± 7% -3.69% (p=0.001 n=20+20)
SSA 7.10s ± 5% 6.85s ± 8% -3.53% (p=0.001 n=19+20)
Flate 124ms ±15% 116ms ±22% -6.57% (p=0.024 n=18+19)
GoParser 156ms ±26% 147ms ±34% ~ (p=0.070 n=19+19)
Reflect 406ms ± 9% 387ms ±21% -4.69% (p=0.028 n=19+20)
Tar 163ms ±15% 162ms ±27% ~ (p=0.370 n=19+19)
XML 223ms ±13% 218ms ±14% ~ (p=0.157 n=20+20)
LinkCompiler 503ms ±21% 484ms ±23% ~ (p=0.072 n=20+20)
ExternalLinkCompiler 1.27s ± 7% 1.22s ± 8% -3.85% (p=0.005 n=20+19)
LinkWithoutDebugCompiler 294ms ±17% 273ms ±11% -7.16% (p=0.001 n=19+18)
(https://perf.golang.org/search?q=upload:20200428.8)
The binary size improvement is even slightly better when you include
the CLs leading up to this. Relative to the parent of "cmd/compile:
mark PanicBounds/Extend as calls":
name old exe-bytes new exe-bytes delta
BinGoSize 15.0MB ± 0% 14.1MB ± 0% -6.18%
name old pcln-bytes new pcln-bytes delta
BinGoSize 3.22MB ± 0% 2.48MB ± 0% -22.92%
(https://perf.golang.org/search?q=upload:20200428.9)
For #36365.
Change-Id: I69448e714f2a44430067ca97f6b78e08c0abed27
Reviewed-on: https://go-review.googlesource.com/c/go/+/230544
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
A debugger can inject a call at almost any PC, which causes
significant complications with stack scanning and growth. Currently,
the runtime solves this using precise stack maps and register maps at
nearly all PCs, but these extra maps require roughly 5% of the binary.
These extra maps were originally considered worth this space because
they were intended to be used for non-cooperative preemption, but are
now used only for debug call injection.
This CL switches from using precise maps to instead using conservative
frame scanning, much like how non-cooperative preemption works. When a
call is injected, the runtime flushes all potential pointer registers
to the stack, and then treats that frame as well as the interrupted
frame conservatively.
The limitation of conservative frame scanning is that we cannot grow
the goroutine stack. That's doable because the previous CL switched to
performing debug calls on a new goroutine, where they are free to grow
the stack.
With this CL, there are no remaining uses of precise register maps
(though we still use the unsafe-point information that's encoded in
the register map PCDATA stream), and stack maps are only used at call
sites.
For #36365.
Change-Id: Ie217b6711f3741ccc437552d8ff88f961a73cee0
Reviewed-on: https://go-review.googlesource.com/c/go/+/229300
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Currently, when a debugger injects a call, that call happens on the
goroutine where the debugger injected it. However, this requires
significant runtime complexity that we're about to remove.
To prepare for this, this CL switches to a different approach that
leaves the interrupted goroutine parked and runs the debug call on a
new goroutine. When the debug call returns, it resumes the original
goroutine.
This should be essentially transparent to debuggers. It follows the
exact same call injection protocol and ensures the whole protocol
executes indivisibly on a single OS thread. The only difference is
that the current G and stack now change part way through the protocol.
For #36365.
Change-Id: I68463bfd73cbee06cfc49999606410a59dd8f653
Reviewed-on: https://go-review.googlesource.com/c/go/+/229299
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Whitelists functions debugCall32 through debugCall65536 in
runtime.debugCallCheck so that any instruction inside those functions
is considered a safe point.
This is useful for implementing nested function calls.
For example when evaluating:
f(g(x))
The debugger should:
1. initiate the call to 'f' until the entry point of 'f',
2. complete the call to 'g(x)'
3. copy the return value of 'g(x)' in the arguments of 'f'
4. complete the call to 'f'
Similarly for:
f().amethod()
The debugger should initiate the call to '.amethod()', then initiate
and complete the call to f(), copy the return value to the arguments
of '.amethod()' and finish its call.
However in this example, unlike the other example, it may be
impossible to determine the entry point of '.amethod()' until after
'f()' is evaluated, which means that the call to 'f()' needs to be
initiated while stopped inside a debugCall... function.
Change-Id: I575c23542709cedb1a171d63576f7e11069c7674
Reviewed-on: https://go-review.googlesource.com/c/go/+/161137
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
This adds a mechanism for debuggers to safely inject calls to Go
functions on amd64. Debuggers must participate in a protocol with the
runtime, and need to know how to lay out a call frame, but the runtime
support takes care of the details of handling live pointers in
registers, stack growth, and detecting the trickier conditions when it
is unsafe to inject a user function call.
Fixes#21678.
Updates derekparker/delve#119.
Change-Id: I56d8ca67700f1f77e19d89e7fc92ab337b228834
Reviewed-on: https://go-review.googlesource.com/109699
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Michael Pratt
limeidan
Michael Anthony Knyszek
Archana
Austin Clements
eric fang
Russ Cox
Josh Bleecher Snyder
Cherry Mui
chainhelen
Filippo Valsorda
Alessandro Arzilli