Filippo Valsorda [Thu, 13 Jun 2019 22:33:33 +0000 (18:33 -0400)]
crypto/tls: disable RSA-PSS in TLS 1.2 again
Signing with RSA-PSS can uncover faulty crypto.Signer implementations,
and it can fail for (broken) small keys. We'll have to take that
breakage eventually, but it would be nice for it to be opt-out at first.
TLS 1.3 requires RSA-PSS and is opt-out in Go 1.13. Instead of making a
TLS 1.3 opt-out influence a TLS 1.2 behavior, let's wait to add RSA-PSS
to TLS 1.2 until TLS 1.3 is on without opt-out.
Note that since the Client Hello is sent before a protocol version is
selected, we have to advertise RSA-PSS there to support TLS 1.3.
That means that we still support RSA-PSS on the client in TLS 1.2 for
verifying server certificates, which is fine, as all issues arise on the
signing side. We have to be careful not to pick (or consider available)
RSA-PSS on the client for client certificates, though.
We'd expect tests to change only in TLS 1.2:
* the server won't pick PSS to sign the key exchange
(Server-TLSv12-* w/ RSA, TestHandshakeServerRSAPSS);
* the server won't advertise PSS in CertificateRequest
(Server-TLSv12-ClientAuthRequested*, TestClientAuth);
* and the client won't pick PSS for its CertificateVerify
(Client-TLSv12-ClientCert-RSA-*, TestHandshakeClientCertRSAPSS,
Client-TLSv12-Renegotiate* because "R" requests a client cert).
Client-TLSv13-ClientCert-RSA-RSAPSS was updated because of a fix in the test.
Than McIntosh [Wed, 19 Jun 2019 17:33:33 +0000 (13:33 -0400)]
cmd/link: macos: set initial protection of 0 for __DWARF segment
For later versions of MacOS, the dynamic loader is more picky about
enforcing restrictions on __DWARF MachO load commands/segments,
triggering aborts of the form
dyld: malformed mach-o image: segment __DWARF has vmsize < filesize
for Go programs that use cgo on Darwin. The error is being triggered
because the Go linker is setting "vmsize" in the DWARF segment entry
to zero as a way to signal that the DWARF doesn't need to be mapped
into memory at runtime (which we need to continue to do).
This patch changes the initial protection on the __DWARF segment to
zero, which dyld seems to be happy with (this is used for other similar
non-loadable sections such as __LLVM).
Than McIntosh [Wed, 19 Jun 2019 15:41:54 +0000 (11:41 -0400)]
cmd/link: fix stale link to MachO file format reference in comment
Fix a stale reference to Apple's Mach-O file format reference in the
header comment.
Change-Id: I5f120fd5bf31ee0b8b29a33879305abb31a7913d
Reviewed-on: https://go-review.googlesource.com/c/go/+/182957 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Bryan C. Mills [Wed, 12 Jun 2019 22:07:32 +0000 (18:07 -0400)]
cmd/go/internal/modfetch: re-resolve commit hashes in readDiskStat
Previously, when we resolved a commit hash (not a complete version),
we always checked the contents of the module cache for any
pseudo-version matching that commit.
However, there are many possible names for a given commit. Generally
the semantically-highest valid name is the best, and that may change
over time as new tags are added, so if we are able to fetch a better
name from upstream we should do so. Otherwise, we should fall back to
the highest appropriate name found in the cache.
Fixes #27171
Updates #27173
Change-Id: Ib5c7d99eb463af84674e969813039cbbee7e395b
Reviewed-on: https://go-review.googlesource.com/c/go/+/182178
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Jay Conrod <jayconrod@google.com> Reviewed-by: roger peppe <rogpeppe@gmail.com>
Raghavendra Nagaraj [Tue, 18 Jun 2019 08:30:24 +0000 (08:30 +0000)]
net/http: fix Server.IdleTimeout and Server.ReadHeaderTimeout docs
CL 46434 changed the doc for Server.IdleTimeout to include
falling back to Server.ReadHeaderTimeout if both
Server.IdleTimeout and Server.ReadTimeout are zero.
However, we explicitly set the ReadDeadlines firstly based
off Server.IdleTimeout or Server.ReadTimeout before attempting
to read the next request, thus the current doc is incorrect.
This CL reverts CL 46434 and also updates the doc for
Server.ReadHeaderTimeout to documenting falling back
to Server.ReadTimeout, if the former is zero, otherwise
there is no timeout.
Jay Conrod [Tue, 18 Jun 2019 19:31:18 +0000 (15:31 -0400)]
cmd/go: fix sumdb test failure with misbehaving DNS server
Broadened the regular expression used to test error messages for
failing to connect to "localhost.localdev/sumdb". Some DNS servers
resolve unknown domains like "localhost.localdev" to real IP addresses
to serve ads. We may get a variety of error messages.
Fixes #31779
Change-Id: Ib389c633c9a9f70f8e89bbcba5282a375da4e708
Reviewed-on: https://go-review.googlesource.com/c/go/+/182799
Run-TryBot: Jay Conrod <jayconrod@google.com> Reviewed-by: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
reflect,doc: use "the" instead of "a" in IsZero docs
There is a subtle distinction between a value
*being* the zero value vs being *equal to* the zero value.
This was discussed at length in #31450.
Using "a zero value" in the docs suggests that there may
be more than zero value. That is possible on the "equal to
zero value" reading, but not the "is zero" reading that we
selected for the semantics of IsZero.
This change attempts to prevent any confusion on this front by
switching to "the zero value" in the documentation.
And while we're here, eliminate a double-space.
(Darn macbook keyboards.)
Jay Conrod [Mon, 17 Jun 2019 21:03:55 +0000 (17:03 -0400)]
cmd/go/internal/modload: query correct "latest" version through proxy
This fixes a regression introduced in CL 180337. When we query a
module at "latest" that has no tagged versions, we tried to use ""
as the version because we used info.Name instead of info.Version. This
only happened when using a proxy: in direct mode, info.Name is set to
the underlying VCS revision, which is fine.
Also: serve "/mod/path/@latest" through our test proxy.
Previously, we served a 404, which made this bug hard to detect.
Fixes #32636
Change-Id: I5c60975656297f862cad66675170e819685ebd39
Reviewed-on: https://go-review.googlesource.com/c/go/+/182697
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Bryan C. Mills <bcmills@google.com>
This change updates the doc comments of the various ParseGlob functions
and methods to state that they use the semantics of filepath.Match when
matching the file name pattern.
Fixes #30608
Change-Id: Iee4bdc0a2a2f8647d1f9a910e4d72a5de9204d11
Reviewed-on: https://go-review.googlesource.com/c/go/+/179739 Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Samuel Tan [Tue, 11 Jun 2019 05:18:56 +0000 (22:18 -0700)]
html/template: handle nil Error values in context.String
Add a special case to print a generic nil error when context.err is
nil.
Previously, this case was unchecked, leading to a call to (*Error).Error
with a nil receiver, which was triggering a nil pointer access. However,
this bug was masked by the panic-recovery code in package fmt.
I tested this change by running `dlv test` in src/html/template, running
the `continue` command, and verifying that no "bad access" errors are
returned.
Fixes #28854
Change-Id: I0b637b943de003d9efc294f6f1e49b793668d037
Reviewed-on: https://go-review.googlesource.com/c/go/+/181579 Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Jay Conrod [Thu, 13 Jun 2019 23:56:37 +0000 (19:56 -0400)]
cmd/go: document GOBIN and 'go install' locations
* In doc/install-source.html, clarify the meaning of $GOBIN and
describe where executables from the Go distribution are
installed. Also describe $GOPATH, since it provides a default value
for $GOBIN and may conflict with $GOROOT.
* Add more detail to 'go help install' as well.
Fixes #31576
Change-Id: Ib8a8c21677c3aa0ebef97a3b587b6f8fe338b80e
Reviewed-on: https://go-review.googlesource.com/c/go/+/182341
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Bryan C. Mills <bcmills@google.com>
Ian Lance Taylor [Thu, 13 Jun 2019 19:49:03 +0000 (12:49 -0700)]
runtime: use dispatch semaphores on Darwin
Changes Darwin semaphore support from using pthread mutexes and
condition variables to using dispatch semaphores. Signaling a dispatch
semaphore is async-signal-safe.
Fixes #31264
Change-Id: If0ce47623501db13e3804b14ace5f4d8eaef461e
Reviewed-on: https://go-review.googlesource.com/c/go/+/182258 Reviewed-by: Elias Naur <mail@eliasnaur.com> Reviewed-by: Keith Randall <khr@golang.org>
Jay Conrod [Fri, 31 May 2019 22:56:28 +0000 (18:56 -0400)]
cmd/go: avoid accidental downgrades in 'go get' with latest and patch
Currently, 'go get -u' and 'go get -u=patch' avoid accidentally
downgrading modules by preventing upgrades in two cases:
1) If the current version is a prerelease that is semantically later
than the "latest" or "patch" version.
2) If the current version is a pseudoversion that is chronologically
newer than the "latest" or "patch" version.
With this change, 'go get m@latest' and 'go get m@patch' prevent
downgrades using the same checks.
Also: 'go get m@patch' now works if m is a module path but not a
package path (i.e., there is no package in the module root directory).
Fixes #30634
Fixes #32537
Change-Id: I916630c385b5f3ba7c13e0d65ba08f73a1a67829
Reviewed-on: https://go-review.googlesource.com/c/go/+/180337
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Bryan C. Mills <bcmills@google.com>
Katie Hockman [Wed, 12 Jun 2019 21:50:55 +0000 (17:50 -0400)]
doc: clarify default go command behavior in the release notes
Change-Id: I2a0bd295ad9737581d149a7165191b878ae2acda
Reviewed-on: https://go-review.googlesource.com/c/go/+/181880 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Daniel Theophanes [Fri, 26 Apr 2019 19:49:23 +0000 (12:49 -0700)]
database/sql: add support for decimal interface
Add support for scanning decimal types into values. If the dest
supports the decimal composer interface and the src supports
the decimal decomposer, set the value of the decimal when Scanning.
Add support for sending decimal decomposer interface values
as parameters.
For #30870
Change-Id: Ic5dbf9069df8d56405852b17542a9188d55c2947
Reviewed-on: https://go-review.googlesource.com/c/go/+/174181
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Daniel Theophanes [Fri, 26 Apr 2019 21:09:07 +0000 (14:09 -0700)]
database/sql: add Conn.Raw to expose the driver Conn safely
Exposing the underlying driver conn will allow the use of the
standard connection pool while still able to run special function
directly on the driver.
Fixes #29835
Change-Id: Ib6d3b9535e730f008916805ae3bf76e4494c88f9
Reviewed-on: https://go-review.googlesource.com/c/go/+/174182
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Julie [Wed, 12 Jun 2019 17:54:51 +0000 (13:54 -0400)]
doc: add release notes for reflect
Change-Id: I71a6816f54f8ad0f8531bb3f9de552fd136a0ed4
Reviewed-on: https://go-review.googlesource.com/c/go/+/181943 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Julie [Wed, 12 Jun 2019 17:11:03 +0000 (13:11 -0400)]
doc: release notes for html/template
Change-Id: Ifdc3c5b840e6833f14c8e52948e45d5faa5a0615
Reviewed-on: https://go-review.googlesource.com/c/go/+/181940 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Daniel Theophanes [Fri, 5 Apr 2019 17:33:43 +0000 (10:33 -0700)]
database/sql/driver: document Valuer must not panic
While it is possible for the connection pool to guard against panics
on every valuer read, this seems like a high cost to be added,
in both code complexity and possible runtime performance.
Most uses of the Valuer will be trivial, like returning
a struct field. Optimize for that case. If sometime may panic the
valuer should itself use recover and return an error.
Fixes #26332
Change-Id: Iad18780b8028f669f5a7841b74a5384d62fb6a7e
Reviewed-on: https://go-review.googlesource.com/c/go/+/170700 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Dmitri Shuralyov [Wed, 12 Jun 2019 18:59:23 +0000 (14:59 -0400)]
doc: mention os.UserConfigDir in release notes
This change makes the release notes for Go 1.13 more complete
by mentioning a new function in the os package.
Change-Id: I0d637fd70ff6d14782bbfb7c13985a0f83b19d6d
Reviewed-on: https://go-review.googlesource.com/c/go/+/181945 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Russ Cox [Tue, 11 Jun 2019 17:53:12 +0000 (13:53 -0400)]
cmd/go: add GOPRIVATE environment variable
It is too confusing to have to set GONOSUMDB and GONOPROXY
in common use cases, but one cannot be guaranteed to be a
subset of the other.
This CL adds GOPRIVATE, which takes the same kind of pattern list
but is defined as "these patterns are private (non-public) modules".
Today the implication is that GOPRIVATE is the default setting for
GONOSUMDB and GONOPROXY. If there are other accommodations
to make for private packages in the future or in other tools,
having this clear statement of intent will let us do that.
(For example maybe an IDE integration would hyperlink an import
path to godoc.org; consulting GOPRIVATE would be a reasonable
way to decide not to do that for certain imports. In contrast,
consulting GONOPROXY or GONOSUMDB clearly would not.)
Matthew Dempsky [Wed, 12 Jun 2019 02:52:58 +0000 (19:52 -0700)]
cmd/compile: fix range analysis of small signed integers
For int8, int16, and int32, comparing their unsigned value to MaxInt64
to determine non-negativity doesn't make sense, because they have
negative values whose unsigned representation is smaller than that.
Fix is simply to compare with the appropriate upper bound based on the
value type's size.
Fixes #32560.
Change-Id: Ie7afad7a56af92bd890ba5ff33c86d1df06cfd9a
Reviewed-on: https://go-review.googlesource.com/c/go/+/181797
Run-TryBot: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com> Reviewed-by: David Chase <drchase@google.com> Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Andrew Bonventre [Tue, 11 Jun 2019 22:09:10 +0000 (18:09 -0400)]
doc: add release notes for the bytes, strings, and time packages
Change-Id: Idb5bf2a61bff635e3ebd926bdeacf943578ac874
Reviewed-on: https://go-review.googlesource.com/c/go/+/181681 Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Bryan C. Mills <bcmills@google.com>
Bryan C. Mills [Tue, 11 Jun 2019 15:49:09 +0000 (11:49 -0400)]
cmd/vet: include the errors.As check from upstream x/tools
This change revendors golang.org/x/tools to include the check and
modifies cmd/vet to add it to the command.
CL 179977 will enable the check by default for 'go test'.
Commands run (starting in GOROOT/src):
cd cmd
emacs vet/main.go
go get -u=patch golang.org/x/tools/go/analysis/passes/errorsas@latest
go mod tidy
go mod vendor
cd ..
./make.bash
go test all
Updates #31213
Change-Id: Ic2ba9bd2d31c4c5fd9e7c42ca14e8dc38520c93b
Reviewed-on: https://go-review.googlesource.com/c/go/+/181717 Reviewed-by: Jonathan Amsterdam <jba@google.com>
Bryan C. Mills [Mon, 10 Jun 2019 16:31:13 +0000 (12:31 -0400)]
cmd/go: in TestScript, set $GOEXE instead of $exe
$GOEXE exists and is documented in 'go env', so $exe is redundant and
a bit confusing. Notably, mod_modinfo.txt already assumes that GOEXE
is set (even though it isn't), and thus fails on Windows.
After this CL, `go test cmd/go/...` passes on a windows-amd64-2016
builder. However, given that the $PATH on the builder is very minimal
(#32430) and network access is limited, tests that rely on binaries
(such as 'git') or external networking may still be broken.
Updates #25300
Change-Id: I9d80f2a0fbaa8bc35fa2205b6898aeccecda4e94
Reviewed-on: https://go-review.googlesource.com/c/go/+/181542
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Bryan C. Mills [Mon, 10 Jun 2019 15:04:29 +0000 (11:04 -0400)]
cmd/go: in tests, don't assume that the 'git' binary is present
Add a helper-function to testenv to make these skips more ergonomic.
Also update a few existing skips in cmd/go/... to use it.
Updates #25300
Change-Id: I4205b4fb2b685dfac1cff3c999f954bff7b0f3c1
Reviewed-on: https://go-review.googlesource.com/c/go/+/181538 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Keith Randall [Sat, 8 Jun 2019 16:57:59 +0000 (12:57 -0400)]
syscall: fix Getdirentries on 32-bit freebsd 12
On freebsd 12, the system call for getdirentries writes 64 bits to
*basep, even on 32-bit systems. Accomodate that by providing a uint64
to the system call and copy the base to/from that uint64.
The uint64 seems to be a virtual file offset, so failing if the high
bits are not zero should be fine for reasonable-sized directories.
Dmitri Shuralyov [Sun, 9 Jun 2019 16:04:23 +0000 (12:04 -0400)]
cmd/go: fix syntax mistake in a testscript file, take 2
This is a followup to CL 181278 and CL 181177.
According to cmd/go/testdata/script/README:
Each line is parsed into a sequence of space-separated command words,
with environment variable expansion and # marking an end-of-line comment.
Adding single quotes around text keeps spaces in that text from being treated
as word separators and also disables environment variable expansion.
We want $HOME to be expanded, so leave it out of the single-quoted
block of text.
I tested this change on macOS, and it makes TestScript/env_write pass.
Fixes #32503
Change-Id: I13621aec82263e5cb6978c13a1ad71d2210a0e42
Reviewed-on: https://go-review.googlesource.com/c/go/+/181418
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org> Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Daniel Martí [Fri, 7 Jun 2019 09:39:21 +0000 (10:39 +0100)]
os: change UserConfigDir on Darwin to ~/Library/Application Support
The old code used ~/Library/Preferences, which is documented by
Apple as:
This directory contains app-specific preference files. You
should not create files in this directory yourself. Instead, use
the NSUserDefaults class or CFPreferences API to get and set
preference values for your app.
It looks like we missed everything after the first sentence; it's
definitely not the right choice for files that Go programs and users
should be touching directly.
Instead, use ~/Library/Application Support, which is documented as:
Use this directory to store all app data files except those
associated with the user’s documents. For example, you might use
this directory to store app-created data files, configuration
files, templates, or other fixed or modifiable resources that
are managed by the app. An app might use this directory to store
a modifiable copy of resources contained initially in the app’s
bundle. A game might use this directory to store new levels
purchased by the user and downloaded from a server.
This seems in line with what UserConfigDir is for, so use it.
The documentation quotes above are obtained from the surprisingly long
link below:
Keith Randall [Fri, 7 Jun 2019 17:22:53 +0000 (13:22 -0400)]
cmd/link: fix deferreturn detector
The logic for detecting deferreturn calls is wrong.
We used to look for a relocation whose symbol is runtime.deferreturn
and has an offset of 0. But on some architectures, the relocation
offset is not zero. These include arm (the offset is 0xebfffffe) and
s390x (the offset is 6).
This ends up setting the deferreturn offset at 0, so we end up using
the entry point live map instead of the deferreturn live map in a
frame which defers and then segfaults.
Instead, use the IsDirectCall helper to find calls.
Brad Fitzpatrick [Fri, 7 Jun 2019 17:56:24 +0000 (17:56 +0000)]
net/http: support BaseContext & ConnContext for http2 Server
This is the net/http half of #32476. This supplies the method needed
by the other half in x/net/http2 in the already-submitted CL 181259,
which this CL also bundles in h2_bundle.go.
Thanks to Tom Thorogood (@tmthrgd) for the bug report and test.
Fixes #32476
Updates #30694
Change-Id: I79d2a280e486fbf75d116f6695fd3abb61278765
Reviewed-on: https://go-review.googlesource.com/c/go/+/181260
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Austin Clements [Thu, 6 Jun 2019 21:27:14 +0000 (17:27 -0400)]
cmd/dist,cmd/compile: remove -allabis mode
dist passes the -allabis flag to the compiler to avoid having to
recreate the cross-package ABI logic from cmd/go. However, we removed
that logic from cmd/go in CL 179863 and replaced it with a different
mechanism that doesn't depend on the build system. Hence, passing
-allabis in dist is no longer necessary.
This CL removes -allabis from dist and, since that was the only use of
it, removes support for it from the compiler as well.
Matt Layher [Fri, 7 Jun 2019 17:07:32 +0000 (13:07 -0400)]
syscall: refer to Proc.Call documentation for LazyProc.Call on Windows
The documentation comment was duplicated for each of these methods, and
the LazyProc.Call documentation incorrectly mentioned that Call accepts
only 15 arguments, but it actually accepts 18 now.
To prevent further documentation drift, refer the reader to the
documentation for Proc.Call instead of duplicating it for LazyProc.Call.
In addition, note that LazyProc's Addr, Call, and Find methods each
trigger a procedure lookup.
Constantin Konstantinidis [Sat, 1 Jun 2019 16:14:04 +0000 (18:14 +0200)]
cmd/go: fix error messages for go mod download in GOPATH mode
Checks if modules are enabled in GOPATH mode.
Error message returned when no version is provided. Relevant tests
updated. Test for GO111MODULE=off added.
Fixes #27783
Change-Id: I12cdaced5fa38a9c49c0ecfed4c479eb86ed061f
Reviewed-on: https://go-review.googlesource.com/c/go/+/179998
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Bryan C. Mills <bcmills@google.com>
Daniel Martí [Fri, 31 May 2019 09:46:00 +0000 (10:46 +0100)]
cmd/go: recommend -d when -m is used
In #32038, it was decided to remove get's -m, since one former use case
is removed, and the other can be done via -d, as pointed by Russ.
However, a user getting this short error might not realise that they can
switch to -d to skip building packages. Add a short mention to point
them in the right direction.
It's important to note "packages", because -m was a flag that acted on
modules, while -d acts on packages. Simply replacing -m with -d might
not be enough in some cases because of that distinction.
Change-Id: I0947b25c4223bdad3cd0e535848527da8db8a16d
Reviewed-on: https://go-review.googlesource.com/c/go/+/179361 Reviewed-by: Jay Conrod <jayconrod@google.com> Reviewed-by: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Daniel Martí [Tue, 16 Apr 2019 13:13:47 +0000 (22:13 +0900)]
text/template: clarify the safety of Template.New
In particular, the returned template isn't independent from the parent.
For example, it can't be parsed concurrently with other children
templates. Only methods which are explicitly safe for concurrent use,
like Execute, may be used concurrently.
Fixes #30281.
Change-Id: Idc84bf4199c035316cdb83b950fd4a8f2a71cd0c
Reviewed-on: https://go-review.googlesource.com/c/go/+/172297
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Andrew Gerrand <adg@golang.org>
Austin Clements [Thu, 6 Jun 2019 21:23:19 +0000 (17:23 -0400)]
runtime/internal/atomic: remove erroneous ABI wrappers
CL 179862 introduced go:linkname directives to create ABI wrappers for
Store and Store64 on s390x, but a concurrent change (CL 180439)
replaced the Go definitions of these functions with assembly
definitions. This resulted in conflicting definitions for the ABI0
symbols, which led to a bootstrap linking failure.
Fix this by removing the now-incorrect go:linkname directives for
Store and Store64. This should fix the linux-s390x builders.
Updates #31230.
Change-Id: I8de8c03c23412fc217d428c0018cc56eb2f9996f
Reviewed-on: https://go-review.googlesource.com/c/go/+/181078 Reviewed-by: Bryan C. Mills <bcmills@google.com>
Russ Cox [Wed, 5 Jun 2019 23:59:58 +0000 (19:59 -0400)]
net: remove non-cgo macOS resolver code
The built-in Go resolver works significantly better.
In particular, the use of res_search does not support
CNAME or PTR queries and may not even be thread-safe.
This CL is essentially a revert of CL 166297 plus fixes,
including CL 180842.
See CL 180842 for additional notes about problems
with this approach.
Russ Cox [Wed, 5 Jun 2019 16:35:29 +0000 (12:35 -0400)]
net: fix non-cgo macOS resolver code
This code was added in April in CL 166297, for #12524.
This CL fixes the following problems in the code:
- The test for failure in the assembly stubs checked for
64-bit -1 instead of 32-bit -1 to decide to fetch errno.
- These C routines (res_init and res_search) don't set errno anyway,
so the Go code using errno to decide success is incorrect.
(The routines set h_errno, which is a racy global variable
that can't safely be consulted, storing values in a different
error space.)
- The Go call passed res_search a non-NUL-terminated name.
- The C res_search rejects calls asking for TypeALL as opposed to
more specific answers like TypeA/TypeAAAA/TypeCNAME,
breaking cgoLookupHost in all cases and cgoLookupIP
except with IP-version-specific networks.
- The DNS response packet was parsed twice, once with msg.Unpack
(discarded), and once with the lower-level dnsmessage.Parser.
The Parser loop was missing a call to p.SkipAllQuestions, with the
result that no DNS response packet would ever parse successfully.
- The parsing of the DNS response answers, if reached, behaved as if
that the AResource and AAAAResource record contained textual
IP addresses, while in fact they contain binary ones. The calls to
parseIPv4 and parseIPv6 therefore would always returns nil,
so that no useful result would be returned from the resolver.
With these fixes, cgoLookupIP can correctly resolve google.com
and return both the A and AAAA addresses.
Even after fixing all these things, TestGoLookupIP still fails,
because it is testing that in non-cgo builds the cgo stubs
correctly report "I can't handle the lookup", and as written the
code intentionally violates that expectation.
This CL adds new direct tests of the pseudo-cgo routines.
The direct IP address lookups succeed, but the CNAME query
causes res_search to hang, and the PTR query fails unconditionally
(a trivial C program confirms these behaviors are due to res_search itself).
Traditionally, res_search is only intended for single-threaded use.
It is unclear whether this one is safe for use from multiple goroutines.
If you run net.test under lldb, that causes syslog messages to be
printed to standard error suggesting double-free bugs:
2019-06-05 19:52:43.505246-0400 net.test[6256:6831076] dnssd_clientstub DNSServiceRefDeallocate called with invalid DNSServiceRef 0x5c000f0 FFFFFFFFDDDDDDDD
2019-06-05 19:52:43.505274-0400 net.test[6256:6831076] dnssd_clientstub DNSServiceRefDeallocate called with invalid DNSServiceRef 0x5c000f0 FFFFFFFFDDDDDDDD
2019-06-05 19:52:43.505303-0400 net.test[6256:6831076] dnssd_clientstub DNSServiceRefDeallocate called with invalid DNSServiceRef 0x5c000f0 FFFFFFFFDDDDDDDD
2019-06-05 19:52:43.505329-0400 net.test[6256:6831076] dnssd_clientstub DNSServiceRefDeallocate called with invalid DNSServiceRef 0x5c000f0 FFFFFFFFDDDDDDDD
This res_search is from libsystem_info; a normal C program would
get res_search (#defined to res_9_search) from libresolv instead.
It is unclear what the relation between the two is.
Issue #12524 was about supporting the /etc/resolver directory tree,
but only libresolv contains code for that; libsystem_info does not.
So this code probably does not enable use of /etc/resolver.
In short:
- Before this CL, the code clearly had never run successfully.
- The code appears not to improve upon the usual non-cgo fallback.
- The code carries with it no tests of improved behavior.
- The code breaks existing tests.
- Calling res_search does not work for PTR/CNAME queries,
so the code breaks existing behavior, even after this CL.
- It's unclear whether res_search is safe to call from multiple threads.
- It's unclear whether res_search is used by any other macOS programs.
Given this, it probably makes sense to delete this code rather
than rejigger the test. This CL fixes the code first, so that there
is a working copy to bring back later if we find out that it really
is necessary.
Russ Cox [Wed, 5 Jun 2019 18:51:57 +0000 (14:51 -0400)]
runtime: document, fix libc error checks on macOS
It matters whether we are calling a function that would
return a 32-bit or 64-bit -1 on error. A few sites were wrong
and this key detail was omitted from syscall/syscallX docs.
This removes the special case for finding assembly references to Go
symbols in runtime and runtime/internal/atomic. These are no longer
necessary because we've now marked all symbols in these packages that
must be accessible from assembly in other packages.
Austin Clements [Fri, 31 May 2019 20:38:56 +0000 (16:38 -0400)]
runtime: mark all Go symbols called from assembly in other packages
This marks all Go symbols called from assembly in other packages with
"go:linkname" directives to ensure they get ABI wrappers.
Now that we have this go:linkname convention, this also removes the
abi0Syms definition in the runtime, which was used to give morestackc
an ABI0 wrapper. Instead, we now just mark morestackc with a
go:linkname directive.
This was tested with buildall.bash in the default configuration, with
-race, and with -gcflags=all=-d=ssa/intrinsics/off. Since I couldn't
test cgo on non-Linux configurations, I manually grepped for runtime
symbols in runtime/cgo.
Austin Clements [Fri, 31 May 2019 19:45:06 +0000 (15:45 -0400)]
cmd/compile: make the second argument to go:linkname optional
The //go:linkname directive can be used to make a symbol accessible to
another package (when it wouldn't normally be). Sometimes you want to
do this without actually changing the symbol's object file symbol
name; for example, in gccgo this makes unexported symbols non-static,
and in gc this provides ABI0 wrappers for Go symbols so they can be
called from assembly in other packages. Currently, this results in
stutter like
//go:linkname entersyscall runtime.entersyscall
This CL makes the second argument to go:linkname optional for the case
where the intent is simply to expose the symbol rather than to rename
it in the object file.
Austin Clements [Fri, 31 May 2019 19:32:22 +0000 (15:32 -0400)]
cmd/compile: generate ABI wrappers for //go:linkname'd symbols
Calling a Go symbol from assembly in another package currently results
in a link failure because the Go symbol is defined as ABIInternal, but
the assembly call is from ABI0. In general this is okay because you
shouldn't do this anyway, but there are special cases where this is
necessary, especially between the runtime and packages closely tied to
the runtime in std.
Currently, we address this for runtime symbols with a hack in cmd/go
that knows to scan related packages when building the symabis file for
the runtime and runtime/internal/atomic. However, in addition to being
a messy solution in the first place, this hack causes races in cmd/go
that are difficult to work around.
We considered creating dummy references from assembly in the runtime
to these symbols, just to make sure they get ABI0 wrappers. However,
there are a fairly large number of these symbols on some platforms,
and it can vary significantly depending on build flags (e.g., race
mode), so even this solution is fairly unpalatable.
This CL addresses this by providing a way to mark symbols in Go code
that should be made available to assembly in other packages. Rather
than introduce a new pragma, we lightly expand the meaning of
"//go:linkname", since that pragma already generally indicates that
you're making the symbol available in a way it wasn't before. This
also dovetails nicely with the behavior of go:linkname in gccgo, which
makes unexported symbols available to other packages.
Follow-up CLs will make use of this and then remove the hack from
cmd/go.
Michael Munday [Tue, 4 Jun 2019 18:17:41 +0000 (19:17 +0100)]
cmd/compile, runtime: make atomic loads/stores sequentially consistent on s390x
The z/Architecture does not guarantee that a load following a store
will not be reordered with that store, unless they access the same
address. Therefore if we want to ensure the sequential consistency
of atomic loads and stores we need to perform serialization
operations after atomic stores.
We do not need to serialize in the runtime when using StoreRel[ease]
and LoadAcq[uire]. The z/Architecture already provides sufficient
ordering guarantees for these operations.
David Chase [Wed, 5 Jun 2019 18:53:28 +0000 (14:53 -0400)]
cmd/compile: add -smallframes gc flag for GC latency diagnosis
Shrinks the size of things that can be stack allocated from
10M to 128k for declared variables and from 64k to 16k for
implicit allocations (new(T), &T{}, etc).
Usage: "go build -gcflags -smallframes hello.go"
An earlier GOEXPERIMENT version of this caused only one
problem, when a gc-should-detect-oversize-stack test no
longer had an oversized stack to detect. The change was
converted to a flag to make it easier to access (for
diagnosing "long" GC-related single-thread pauses) and to
remove interference with the test.
Includes test to verify behavior.
Updates #27732.
Change-Id: I1255d484331e77185e07c78389a8b594041204c2
Reviewed-on: https://go-review.googlesource.com/c/go/+/180817
Run-TryBot: David Chase <drchase@google.com> Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Meng Zhuo [Thu, 6 Jun 2019 10:07:13 +0000 (18:07 +0800)]
syscall: skip test if unprivileged_userns_clone sysctl is missing
The original test (CL 166460) didn't check the existence of
/proc/sys/kernel/unprivileged_userns_clone and continue the test
if the file doesn't exist.
Russ Cox [Wed, 5 Jun 2019 16:31:42 +0000 (12:31 -0400)]
runtime: use default system stack size, not 64 kB, on non-cgo macOS
At least one libc call we make
(res_search, which calls _mdns_query and then mdns_item_call)
pushes a 64 kB stack frame onto the stack.
Then it faults on the guard page.
Use the default system stack size, under the assumption
that the C code being called is compatible with that stack size.
For #31705.
Change-Id: I1b0bfc2e54043c49f0709255988ef920ce30ee82
Reviewed-on: https://go-review.googlesource.com/c/go/+/180779
Run-TryBot: Russ Cox <rsc@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Alex Myasoedov [Tue, 4 Jun 2019 18:07:57 +0000 (20:07 +0200)]
doc: clarify safety of multiple and concurent os.(*File).Close() calls
Fixes #32427
Change-Id: I4b863bd3836067dcc2eb3a9c3a7169656763d003
Reviewed-on: https://go-review.googlesource.com/c/go/+/180438 Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Rob Pike <r@golang.org>