If the timeout triggers before writing to the done channel, the
goroutine will be blocked waiting for a corresponding read that’s
no longer existent, thus a goroutine leak. This change fixes that by
using a buffered channel instead.
Change-Id: I9cf4067a58bc5a729ab31e4426edd78bd359e8e0
GitHub-Last-Rev: a7d811a7be
GitHub-Pull-Request: golang/go#40236
Reviewed-on: https://go-review.googlesource.com/c/go/+/242902
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Adds parentheses so as to properly bind <- to the right most
channel.
This meant that previously given:
ChanOf(<-chan T)
it would mistakenly try to look up the type as
chan <-chan T
instead of
chan (<-chan T)
Fixes#39897
Change-Id: I8564916055f5fadde3382e41fe8820a1071e5f13
GitHub-Last-Rev: f8f2abe8d4
GitHub-Pull-Request: golang/go#39898
Reviewed-on: https://go-review.googlesource.com/c/go/+/240280
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Taking the live variable set from the last return point is problematic.
See #40629 for details, but there may not be a return point, or it may
be before the final defer.
Additionally, keeping track of the last call as a *Value doesn't quite
work. If it is dead-code eliminated, the storage for the Value is reused
for some other random instruction. Its live variable information,
if it is available at all, is wrong.
Instead, just mark all the open-defer argument slots as live
throughout the function. (They are already zero-initialized.)
Fixes#40629
Change-Id: Ie456c7db3082d0de57eaa5234a0f32525a1cce13
Reviewed-on: https://go-review.googlesource.com/c/go/+/247522
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>
modload.Init initialized the build cache with the intent of providing
a better error message in Go 1.12, when the build cache became
mandatory (in module mode, packages aren't installed outside the build
cache). Unfortunately, this didn't provide a more descriptive error
(the cache calls base.Fatalf with its own message), and it caused
errors for commands that don't use the cache (like 'go mod edit').
This CL removes the cache initialization from modload.Init. The
builder will initialize it when it's needed.
For #39882
Change-Id: Ibc01ae4e59358dcd08a07ffc97bf556514d0366f
Reviewed-on: https://go-review.googlesource.com/c/go/+/240548
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Michael Matloob <matloob@golang.org>
In CL 239797, str.GlobsMatchPath was copied to golang.org/x/mod/module
as MatchPrefixPatterns. This CL updates x/mod, switches calls to use
the new function, and deletes the old function.
For #38725
Change-Id: I7241032228b574aa539426a92d2f5aad9ee001e2
Reviewed-on: https://go-review.googlesource.com/c/go/+/240061
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Matloob <matloob@golang.org>
modfetch.WriteGoSum now accepts a map[module.Version]bool parameter.
This is used to prevent some new sums from being saved to go.sum when
they would be removed by the next 'go mod tidy'. Previusly, sums were
saved for modules looked up during import resolution.
A new function, modload.TrimGoSum, is also introduced, which marks
sums for deletion. 'go mod tidy' now uses this. The new logic
distinguishes between go.mod sums and content sums, which lets 'go mod
tidy' delete sums for modules in the build graph but not the build
list.
Fixes#31580Fixes#36260Fixes#33008
Change-Id: I06c4125704a8bbc9969de05265967ec1d2e6d3e8
Reviewed-on: https://go-review.googlesource.com/c/go/+/237017
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Matloob <matloob@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
go.modverify was renamed to go.sum before vgo was merged into
cmd/go. It's been long enough that we can safely drop support for it.
For #25525
Change-Id: If8da66280a0fb6a4d4db0b170700775523c18571
Reviewed-on: https://go-review.googlesource.com/c/go/+/240458
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
The Builder isn't needed by MkEnv, and Builder.Init doesn't have side
effects that change the environment. Builder.Init does currently call
CheckGOOSARCHPair, but that's being moved out in CL 234658.
Builder.Init creates the temporary work directory used by the
builder. For the builder created in MkEnv, this directory is never
used. Creating this directory can cause unnecessary errors for
commands that don't use a builder like 'go clean' and 'go list'.
Fixes#38395
Updates #24398
Change-Id: Ib93ae55afdf958000470657f4c4ff5bd92700e46
Reviewed-on: https://go-review.googlesource.com/c/go/+/236563
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Matloob <matloob@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
The prior implementation used the format verb %v which unfortunately
improperly wrapped any underlying scanner errors, and we couldn't use
errors.Is nor errors.As. This change fixes that by using the %w verb.
Added a unit to ensure that both error sub string matching works, but
also that errors.Is works as expected.
Fixes#38099
Change-Id: Iea667041dd8081d961246f77f2542330417292dc
Reviewed-on: https://go-review.googlesource.com/c/go/+/248337
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The optimization that replaces inline markers with pre-existing
instructions assumes that 'Prog' values produced by the compiler are
still reachable after the assembler has run. This was not true on
s390x where the assembler was removing NOP instructions from the
linked list of 'Prog' values. This led to broken inlining data
which in turn caused an infinite loop in the runtime traceback code.
Fix this by stopping the s390x assembler backend removing NOP
values. It does not make any difference to the output of the
assembler because NOP instructions are 0 bytes long anyway.
Fixes#40473.
Change-Id: Ib4fabadd1de8adb80421f75950ee9aad2111147a
Reviewed-on: https://go-review.googlesource.com/c/go/+/247697
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Previously, the assembler removed NOPs from the Prog list in
obj9.go. NOPs shouldn't be removed if they were added as
an inline mark, as described in the issue below.
Fixes#40689
Once the NOPs were left in the Prog list, some instructions
were flagged as invalid because they had an operand which was
not represented in optab. In order to preserve the previous
assembler behavior, entries were added to optab for those
operand cases. They were not flagged as errors before because
the NOP instructions were removed before the code to check the
valid opcode/operand combinations.
Change-Id: Iae5145f94459027cf458e914d7c5d6089807ccf8
Reviewed-on: https://go-review.googlesource.com/c/go/+/247842
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Paul Murphy <murp@ibm.com>
Reviewed-by: Michael Munday <mike.munday@ibm.com>
Reviewed-by: Keith Randall <khr@golang.org>
Minor cleanup: remove the symbol attribute AttrSeenGlobal, since it is
redundant with the existing attribute AttrOnList (no need to have what
amounts to a separate flag for checking the same property).
Change-Id: Ia269b64de37c2bb4a2314bbecf3d2091c6d57424
Reviewed-on: https://go-review.googlesource.com/c/go/+/239477
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Add a draft version of a blurb on improvements to the linker. This
will need to be finalized later in the release since there are still
some additional changes to be made to the linker in 1.16.
Updates #40703.
Change-Id: Id85c7e129071cc2faacb09c53a2968bd52b0a7b4
Reviewed-on: https://go-review.googlesource.com/c/go/+/248238
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Austin Clements <austin@google.com>
Go 1.14 included a (rather awful) workaround for a Linux kernel bug
that corrupted vector registers on x86 CPUs during signal delivery
(https://bugzilla.kernel.org/show_bug.cgi?id=205663). This bug was
introduced in Linux 5.2 and fixed in 5.3.15, 5.4.2 and all 5.5 and
later kernels. The fix was also back-ported by major distros. This
workaround was necessary, but had unfortunate downsides, including
causing Go programs to exceed the mlock ulimit in many configurations
(#37436).
We're reasonably confident that by the Go 1.16 release, the number of
systems running affected kernels will be vanishingly small. Hence,
this CL removes this workaround.
This effectively reverts CLs 209597 (version parser), 209899 (mlock
top of signal stack), 210299 (better failure message), 223121 (soft
mlock failure handling), and 244059 (special-case patched Ubuntu
kernels). The one thing we keep is the osArchInit function. It's empty
everywhere now, but is a reasonable hook to have.
Updates #35326, #35777 (the original register corruption bugs).
Updates #40184 (request to revert in 1.15).
Fixes#35979.
Change-Id: Ie213270837095576f1f3ef46bf3de187dc486c50
Reviewed-on: https://go-review.googlesource.com/c/go/+/246200
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
In Go 1.15 we switched the default linking mode for PIE on
Linux/AMD64 and Linux/ARM64 to internal linking. Clarify that
the previous behavior (external linking) can still be used with
a flag.
Fixes#40719.
Change-Id: Ib7042622bc91e1b1aa31f520990d03b5eb6c56bb
Reviewed-on: https://go-review.googlesource.com/c/go/+/248199
Reviewed-by: Ian Lance Taylor <iant@golang.org>
In the dev.link branch we have continued developing the new object
file format support and the linker improvements described in
https://golang.org/s/better-linker . Since the last merge (May 1st
2020), more progress has been made to improve the new linker, with
improvements on both linker speed and memory usage.
Fixes#40703.
Change-Id: I9924ea88d981845c3a40ec8c25820120fc21c003
This change propagates context into PackagesForErrors and Do for
the purpose of tracing, and calls trace.StartSpan on PackagesForErrors
and Do, so that the trace now shows the broad outline of where
the "Loading" and "Execution" phases are in the build.
Updates #38714
Change-Id: Ib9a7cf7030210f68f76663d1c8a7461e0a226611
Reviewed-on: https://go-review.googlesource.com/c/go/+/238541
Run-TryBot: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
One small step to start propagating the context in
cmd/go for tracing purposes.
Updates #38714
Change-Id: Ibb6debeb9233f84d55f0e81244487355cbe7b82c
Reviewed-on: https://go-review.googlesource.com/c/go/+/237684
Run-TryBot: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
If cmd/go is provided with a -debug-trace=<file> option, cmd/go will write an
execution trace to that file.
Updates #38714
Change-Id: I3e6521343902c08266a0292f4280298a3bf8b725
Reviewed-on: https://go-review.googlesource.com/c/go/+/237683
Run-TryBot: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
The ViewerEvent, ViewerData and ViewerFrame structs are moved into
cmd/internal/traceviewer, and renamed Event, Data, and Frame.
The structs are the same, except for the following: A definition
for the JSON "bp" field that's defined in the trace format, but
missing in the structs has been added. Also, the Tid and Pid fields
on Event have been renamed TID and PID to better match Go style.
Finally, the footer field on ViewerData, which hasn't been used
for a while, has been removed.
This CL is in preparation for the usage of these structs by cmd/go's
tracing functionality.
Updates #38714
Change-Id: I345f23617b96d4629b876ae717f89d56a67e05a3
Reviewed-on: https://go-review.googlesource.com/c/go/+/239098
Run-TryBot: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
This template is based on CL 220278 and previous ones like it.
Include Compiler and Linker sections proactively, they can be
removed if they don't end up being needed for Go 1.16.
Use two spaces of indentation for TODOs to set a better precedent
for the final text that will take its place.
'relnote -html' does not report any changes at this time.
For #40700.
Change-Id: I096b0ce0d33aaaa6fae9c91c0d2dfb89b9c5e94c
Reviewed-on: https://go-review.googlesource.com/c/go/+/248198
Reviewed-by: Carlos Amedee <carlos@golang.org>
This is the start of the Go 1.16 development cycle, so update the
Version value accordingly. It represents the Go 1.x version that
will soon open up for development (and eventually become released).
Historically, we used to bump this at an arbitrary time throughout
the development cycle, but it's better to be more predictable about
updating it. The start of a development cycle should be the most
appropriate time: it clearly marks the boundary between 1.15 and
1.16 development, and doing it early can help catch issues in other
tooling. See issue #38704 for more background.
There is no longer a need to update the list of Go versions in
src/go/build/doc.go because it does not exist as of CL 232981.
For #40705.
Updates #38704.
Updates #37018.
Change-Id: Id8ee733b5e79c53b6cd03509c6560614d8743833
Reviewed-on: https://go-review.googlesource.com/c/go/+/248038
Reviewed-by: Carlos Amedee <carlos@golang.org>
Rewrite part of cmd/pack to use the cmd/internal/archive package.
Change-Id: Ia7688810d3ea4d0277056870091f59cf09cffcad
Reviewed-on: https://go-review.googlesource.com/c/go/+/247917
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Combine objfile2.go into objfile.go.
objfile.go has a lot of code for DWARF generation. Move them to
dwarf.go.
Change-Id: I2a27c672e9e9b8eea35d5e0a71433dcc80b7afa4
Reviewed-on: https://go-review.googlesource.com/c/go/+/247918
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
CL 245485 introduced a map for used files in a function. When
numbering symbols, make sure we traverse the files in
deterministic order.
Should fix longtest builders.
Change-Id: I1006bc5425116ab40e33a61e8f5acd1bdb4abad9
Reviewed-on: https://go-review.googlesource.com/c/go/+/247997
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Read Go object files using cmd/internal/goobj2 package directly,
instead of using cmd/internal/goobj as an intermediate layer.
Now cmd/internal/archive is only about reading archives.
Change-Id: Ifecb217fb26c16c26fc1bbc3fba0ed44710020ed
Reviewed-on: https://go-review.googlesource.com/c/go/+/246443
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
See golang.org/cl/240657, which reverted the original change to fix the
regression reported in golang.org/issue/39427.
Updates #37419.
Change-Id: I39fbaa0b028ee00856cffea38879a631f540f057
Reviewed-on: https://go-review.googlesource.com/c/go/+/247718
Reviewed-by: Andrew Bonventre <andybons@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Andrew Bonventre <andybons@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Rename cmd/internal/goobj package to cmd/internal/archive. This
is in preparation of a refactoring of object and archive file
reading packages.
With this CL, the cmd/internal/archive contains logic about
reading Go object files. This will be moved to other places in
later CLs.
Change-Id: Ided7287492a4766183d6e49be840a7f361504d1d
Reviewed-on: https://go-review.googlesource.com/c/go/+/246442
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
This update was created using the updatecontrib command:
go get golang.org/x/build/cmd/updatecontrib
cd gotip
updatecontrib
With manual changes based on publicly available information
to canonicalize letter case and formatting for a few names.
For #12042.
Change-Id: I66dc5ee28d9a64bc9d150e72d136d8f71e50373b
Reviewed-on: https://go-review.googlesource.com/c/go/+/247767
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: Andrew Bonventre <andybons@golang.org>
Currently, nanotime1 (and walltime1) is not reentrant, in that it
sets m.vdsoSP at entry and clears it at exit. If a signal lands
in between, and nanotime1 is called from the signal handler, it
will clear m.vdsoSP while we are still in nanotime1. If (in the
unlikely event) it is signaled again, m.vdsoSP will be wrong,
which may cause the stack unwinding code to crash.
This CL makes it reentrant, by saving/restoring the previous
vdsoPC and vdsoSP, instead of setting it to 0 at exit.
TODO: have some way to test?
Change-Id: I9ee53b251f1d8a5a489c71d4b4c0df1dee70c3e5
Reviewed-on: https://go-review.googlesource.com/c/go/+/246763
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
In order to prevent renumbering of filenames in pclntab generation, use
the per-package file list (previously only used for DWARF generation) as
file-indices. This is the largest step to eliminate renumbering of
filenames in pclntab.
Note, this is probably not the final state of the file table within the
object file. In this form, the linker loads all filenames for all
objects. I'll move to storing the filenames as regular string
symbols,and defaulting all string symbols to using the larger hash value
to make generation of pcln simplest, and most memory friendly.
Change-Id: I23daafa3f4b4535076e23100200ae0e7163aafe0
Reviewed-on: https://go-review.googlesource.com/c/go/+/245485
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Add a new PPC64-only linker test that does a build with the
-debugppc64textsize debugging option (selecting a lower the threshold
for text section splitting) to verify that no bugs have been
introduced in the linker code that manages this process.
Change-Id: Iea3f16a04c894d528eab2cb52f1ec1d75a2770cc
Reviewed-on: https://go-review.googlesource.com/c/go/+/241499
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Add a new debugging command line option (-debugppc64textsize=N) that
forces the start of a new text section after ".text" hits N bytes as
opposed to the architected limit of 2^26. This is intended to enable
testing of the linker code paths that handle multiple .text sections
on PPC64 without resorting to building giant applications.
Updates #20492.
Change-Id: I74ab7fd1e412e9124de5bd0d8d248c5e73225ae3
Reviewed-on: https://go-review.googlesource.com/c/go/+/241073
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
The code in the the linker's genelfsym() routine was not properly
including runtime.text.%d marker symbols that are emitted on PPC64
when a very large text section is split into chunks. This bug was
introduced in CL 233338 when portions of asmb2() were converted
from sym.Symbol to loader.Sym usage.
Change-Id: Idfed944c41e1805f78f35be67bcdd18bdefd7819
Reviewed-on: https://go-review.googlesource.com/c/go/+/241498
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
This preallocation is way too large, and showed up in the metrics. Just
remove it all together.
Change-Id: Ib4646b63cd0a903656ada244f15e977cde2a2c4c
Reviewed-on: https://go-review.googlesource.com/c/go/+/247177
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
This CL ensures that ReadUvarint consumes only a limited
amount of input (instead of an unbounded amount).
On some inputs, ReadUvarint could read an arbitrary number
of bytes before deciding to return an overflow error.
After this CL, ReadUvarint returns that same overflow
error sooner, after reading at most MaxVarintLen64 bytes.
Fix authored by Robert Griesemer and Filippo Valsorda.
Thanks to Diederik Loerakker, Jonny Rhea, Raúl Kripalani,
and Preston Van Loon for reporting this.
Fixes#40618
Fixes CVE-2020-16845
Change-Id: Ie0cb15972f14c38b7cf7af84c45c4ce54909bb8f
Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/812099
Reviewed-by: Filippo Valsorda <valsorda@google.com>
Reviewed-on: https://go-review.googlesource.com/c/go/+/247120
Run-TryBot: Katie Hockman <katie@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alexander Rakoczy <alex@golang.org>
After golang.org/cl/228784 setLoadPackageDataError tries to decide whether an
error is caused by an imported package or an importing package by examining the
error itself to decide. Ideally, the errors themselves would belong to a
specific interface or some other property to make it unambiguous that they
were import errors. Since they don't, setLoadPackageDataError just checked
for nogoerrors and classified all other errors as import errors. But
it missed scanner errors which are also "caused" by the imported
package.
Fixes#40544
Change-Id: I39159bfdc286bee73697decd07b8aa9451f2db06
Reviewed-on: https://go-review.googlesource.com/c/go/+/246717
Run-TryBot: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Use the original *Request in the reqCanceler map, not the transient
wrapper created to handle body rewinding.
Change the key of reqCanceler to a struct{*Request}, to make it more
difficult to accidentally use the wrong request as the key.
Fixes#40453.
Change-Id: I4e61ee9ff2c794fb4c920a3a66c9a0458693d757
Reviewed-on: https://go-review.googlesource.com/c/go/+/245357
Run-TryBot: Damien Neil <dneil@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
