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Commit Graph

41614 Commits

Author SHA1 Message Date
Aditya Harindar
5c6db9a76f doc/articles: format error string as per go style
First letter of an error string should not be capitalized, as prescribed in the [wiki](https://github.com/golang/go/wiki/Errors).

Change-Id: Iea1413f19b5240d3bef79f216094d210b54bdb62
GitHub-Last-Rev: d8e1671071
GitHub-Pull-Request: golang/go#35203
Reviewed-on: https://go-review.googlesource.com/c/go/+/203797
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-10-28 16:15:54 +00:00
Lynn Boger
0ae9389609 runtime: fix textOff for multiple text sections
If a compilation has multiple text sections, code in
textOff must compare the offset argument against the range
for each text section to determine which one it is in.
The comparison looks like this:

if uintptr(off) >= sectaddr && uintptr(off) <= sectaddr+sectlen

If the off value being compared is equal to sectaddr+sectlen then it
is not within the range of the text section but after it. The
comparison should be just '<'.

Updates #35207

Change-Id: I114633fd734563d38f4e842dd884c6c239f73c95
Reviewed-on: https://go-review.googlesource.com/c/go/+/203817
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-28 15:06:13 +00:00
Lynn Boger
adef06c7a5 crypto/elliptic: add asm implementation for p256 on ppc64le
This adds an asm implementation of the p256 functions used
in crypto/elliptic, utilizing VMX, VSX to improve performance.
On a power9 the improvement is:

elliptic benchmarks:
name            old time/op    new time/op    delta
BaseMult          1.40ms ± 0%    1.44ms ± 0%   +2.66%  (p=0.029 n=4+4)
BaseMultP256       317µs ± 0%      50µs ± 0%  -84.14%  (p=0.029 n=4+4)
ScalarMultP256     854µs ± 2%     214µs ± 0%  -74.91%  (p=0.029 n=4+4)

ecdsa benchmarks:
name           old time/op    new time/op    delta
SignP256          377µs ± 0%     111µs ± 0%  -70.57%  (p=0.029 n=4+4)
SignP384         6.55ms ± 0%    6.48ms ± 0%   -1.03%  (p=0.029 n=4+4)
VerifyP256       1.19ms ± 0%    0.26ms ± 0%  -78.54%  (p=0.029 n=4+4)
KeyGeneration     319µs ± 0%      52µs ± 0%  -83.56%  (p=0.029 n=4+4)

This implemenation is based on the s390x implementation, using
comparable instructions for most with some minor changes where the
instructions are not quite the same.

Some changes were also needed since s390x is big endian and ppc64le
is little endian.

This also enables the fuzz_test for ppc64le.

Change-Id: I59a69515703b82ad2929f68ba2f11208fa833181
Reviewed-on: https://go-review.googlesource.com/c/go/+/168478
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Munday <mike.munday@ibm.com>
2019-10-28 12:35:06 +00:00
Phil Pearl
acbed0372e encoding/json: remove allocation when using a Marshaler with value receiver
If we marshal a non-pointer struct field whose type implements Marshaler with
a non-pointer receiver, then we avoid an allocation if we take the address of
the field before casting it to an interface.

name               old time/op    new time/op    delta
EncodeMarshaler-8     104ns ± 1%      92ns ± 2%  -11.72%  (p=0.001 n=7+7)

name               old alloc/op   new alloc/op   delta
EncodeMarshaler-8     36.0B ± 0%      4.0B ± 0%  -88.89%  (p=0.000 n=8+8)

name               old allocs/op  new allocs/op  delta
EncodeMarshaler-8      2.00 ± 0%      1.00 ± 0%  -50.00%  (p=0.000 n=8+8)

Test coverage already looks good enough for this change. TestRefValMarshal
already covers all possible combinations of value & pointer receivers on
value and pointer struct fields.

Change-Id: I6fc7f72396396d98f9a90c3c86e813690f41c099
Reviewed-on: https://go-review.googlesource.com/c/go/+/203608
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-10-28 11:22:20 +00:00
Tobias Klauser
33e3983db8 cmd/nm, runtime/cgo: add cgo support for freebsd/arm64
Based on work by Mikaël Urankar (@MikaelUrankar).

Updates #24715
Updates #35197

Change-Id: I91144101043d67d3f8444bf8389c9606abe2a66c
Reviewed-on: https://go-review.googlesource.com/c/go/+/199919
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-10-28 10:25:44 +00:00
Dmitri Goutnik
152dddee7e cmd/link: switch to ld.bfd on freebsd/arm64
Updates golang/go#35197

Change-Id: I4fd85c84475761d71d2c17e62796e0a411cf91d8
Reviewed-on: https://go-review.googlesource.com/c/go/+/203519
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
2019-10-28 09:26:37 +00:00
Dan Scales
1f3339f441 runtime: fix dumpgoroutine() to deal with open-coded defers
_defer.fn can be nil, so we need to add a check when dumping
_defer.fn.fn.

Fixes #35172

Change-Id: Ic1138be5ec9dce915a87467cfa51ff83acc6e3a9
Reviewed-on: https://go-review.googlesource.com/c/go/+/203697
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-10-28 01:00:20 +00:00
Phil Pearl
22d377077c encoding/json: improve performance of Compact
This change improves performance of Compact by using a sync.Pool to allow re-use
of a scanner. This also has the side-effect of removing an allocation for each
field that implements Marshaler when marshalling JSON.

name               old time/op    new time/op    delta
EncodeMarshaler-8     118ns ± 2%     104ns ± 1%  -12.21%  (p=0.001 n=7+7)

name               old alloc/op   new alloc/op   delta
EncodeMarshaler-8      100B ± 0%       36B ± 0%  -64.00%  (p=0.000 n=8+8)

name               old allocs/op  new allocs/op  delta
EncodeMarshaler-8      3.00 ± 0%      2.00 ± 0%  -33.33%  (p=0.000 n=8+8)

Change-Id: Ic70c61a0a6354823da5220f5aad04b94c054f233
Reviewed-on: https://go-review.googlesource.com/c/go/+/200864
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-10-27 16:02:29 +00:00
Jason A. Donenfeld
31bfab4ac6 cmd/link: enable DEP for Windows executables
There's no reason not to enable DEP in 2019, especially given Go's
minimum operating system level.

RELNOTE=yes

Change-Id: I9c3bbc5b05a1654876a218123dd57b9c9077b780
Reviewed-on: https://go-review.googlesource.com/c/go/+/203601
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
2019-10-27 09:49:02 +00:00
Jason A. Donenfeld
0d3092ffa7 internal/syscall/windows/registry: remove TestWalkFullRegistry due to false assumptions
This test's existence was predicated upon assumptions about the full
range of known data types and known data into those types. However,
we've learned from Microsoft that there are several undocumented secret
registry types that are in use by various parts of Windows, and we've
learned from inspection that many Microsoft uses of registry types don't
strictly adhere to the recommended value size. It's therefore foolhardy
to make any assumptions about what goes in and out of the registry, and
so this test, as well as its "blacklist", are meaningless.

Fixes #35084

Change-Id: I6c3fe5fb0e740e88858321b3b042c0ff1a23284e
Reviewed-on: https://go-review.googlesource.com/c/go/+/203604
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
2019-10-27 09:45:42 +00:00
Josh Bleecher Snyder
0f559941fb crypto/tls: move a defer out of a loop
Rhys Hiltner noted in #14939 that this defer was
syntactically inside a loop, but was only ever

executed once. Now that defer in a loop
is significantly slower, pull this one out.

name                                    old time/op   new time/op   delta
Throughput/MaxPacket/1MB/TLSv12-8        3.94ms ± 8%   3.93ms ±13%    ~     (p=0.967 n=15+15)
Throughput/MaxPacket/1MB/TLSv13-8        4.33ms ± 3%   4.51ms ± 7%  +4.00%  (p=0.000 n=14+14)
Throughput/MaxPacket/2MB/TLSv12-8        6.80ms ± 6%   7.01ms ± 4%  +3.15%  (p=0.000 n=14+14)
Throughput/MaxPacket/2MB/TLSv13-8        6.96ms ± 5%   6.80ms ± 5%  -2.43%  (p=0.006 n=15+14)
Throughput/MaxPacket/4MB/TLSv12-8        12.0ms ± 3%   11.7ms ± 2%  -2.88%  (p=0.000 n=15+13)
Throughput/MaxPacket/4MB/TLSv13-8        12.1ms ± 3%   11.7ms ± 2%  -3.54%  (p=0.000 n=13+13)
Throughput/MaxPacket/8MB/TLSv12-8        22.2ms ± 3%   21.6ms ± 3%  -2.97%  (p=0.000 n=15+15)
Throughput/MaxPacket/8MB/TLSv13-8        22.5ms ± 5%   22.0ms ± 3%  -2.34%  (p=0.004 n=15+15)
Throughput/MaxPacket/16MB/TLSv12-8       42.4ms ± 3%   41.3ms ± 3%  -2.49%  (p=0.001 n=15+15)
Throughput/MaxPacket/16MB/TLSv13-8       43.4ms ± 5%   42.3ms ± 3%  -2.33%  (p=0.006 n=15+14)
Throughput/MaxPacket/32MB/TLSv12-8       83.1ms ± 4%   80.6ms ± 3%  -2.98%  (p=0.000 n=15+15)
Throughput/MaxPacket/32MB/TLSv13-8       85.2ms ± 8%   82.6ms ± 4%  -3.02%  (p=0.005 n=15+15)
Throughput/MaxPacket/64MB/TLSv12-8        167ms ± 7%    158ms ± 2%  -5.21%  (p=0.000 n=15+15)
Throughput/MaxPacket/64MB/TLSv13-8        170ms ± 4%    162ms ± 3%  -4.83%  (p=0.000 n=15+15)
Throughput/DynamicPacket/1MB/TLSv12-8    4.13ms ± 7%   4.00ms ± 8%    ~     (p=0.061 n=15+15)
Throughput/DynamicPacket/1MB/TLSv13-8    4.72ms ± 6%   4.64ms ± 7%    ~     (p=0.377 n=14+15)
Throughput/DynamicPacket/2MB/TLSv12-8    7.29ms ± 7%   7.09ms ± 7%    ~     (p=0.070 n=15+14)
Throughput/DynamicPacket/2MB/TLSv13-8    7.18ms ± 5%   6.59ms ± 4%  -8.34%  (p=0.000 n=15+15)
Throughput/DynamicPacket/4MB/TLSv12-8    12.3ms ± 3%   11.9ms ± 4%  -3.31%  (p=0.000 n=15+14)
Throughput/DynamicPacket/4MB/TLSv13-8    12.2ms ± 4%   12.0ms ± 4%  -1.91%  (p=0.019 n=15+15)
Throughput/DynamicPacket/8MB/TLSv12-8    22.4ms ± 3%   21.9ms ± 3%  -2.18%  (p=0.000 n=15+15)
Throughput/DynamicPacket/8MB/TLSv13-8    22.7ms ± 3%   22.2ms ± 3%  -2.35%  (p=0.000 n=15+15)
Throughput/DynamicPacket/16MB/TLSv12-8   42.3ms ± 3%   42.1ms ± 3%    ~     (p=0.505 n=14+15)
Throughput/DynamicPacket/16MB/TLSv13-8   42.7ms ± 3%   43.3ms ± 7%    ~     (p=0.123 n=15+14)
Throughput/DynamicPacket/32MB/TLSv12-8   82.8ms ± 3%   81.9ms ± 3%    ~     (p=0.112 n=14+15)
Throughput/DynamicPacket/32MB/TLSv13-8   84.6ms ± 6%   83.9ms ± 4%    ~     (p=0.624 n=15+15)
Throughput/DynamicPacket/64MB/TLSv12-8    166ms ± 4%    163ms ± 6%    ~     (p=0.081 n=15+15)
Throughput/DynamicPacket/64MB/TLSv13-8    165ms ± 3%    168ms ± 3%  +1.56%  (p=0.029 n=15+15)

Change-Id: I22409b05afe761b8ed1912b15c67fc03f88d3d1f
Reviewed-on: https://go-review.googlesource.com/c/go/+/203481
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-10-26 15:17:28 +00:00
Giovanni Bajo
5d000a8b62 test: add test for fixed internal compiler error
Updates #35157 (the bug there was fixed by CL200861)

Change-Id: I67069207b4cdc2ad4a475dd0bbc8555ecc5f534f
Reviewed-on: https://go-review.googlesource.com/c/go/+/203598
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alberto Donizetti <alb.donizetti@gmail.com>
2019-10-26 08:29:23 +00:00
Giovanni Bajo
c70e5475e6 cmd/compile: in poset, implement path collapsing
Sometimes, poset needs to collapse a path making all nodes in
the path aliases. For instance, we know that A<=N1<=B and we
learn that B<=A, we can deduce A==N1==B, and thus we can
collapse all paths from A to B into a single aliased node.

Currently, this is a TODO. This CL implements the path-collapsing
primitive by doing a DFS walk to build a bitset of all nodes
across all paths, and then calling the new aliasnodes that allow
to mark multiple nodes as aliases of a single master node.

This helps only 4 times in std+cmd, but it will be fundamental
when we will rely on poset to calculate numerical limits, to
calculate the correct values.

This also fixes #35157, a bug uncovered by a previous CL in this
serie. A testcase will be added soon.

Change-Id: I5fc54259711769d7bd7c2d166a5abc1cddc26350
Reviewed-on: https://go-review.googlesource.com/c/go/+/200861
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2019-10-26 07:52:35 +00:00
Giovanni Bajo
18d57bc892 cmd/compile: in poset, allow multiple aliases in a single pass
Change aliasnode into aliasnodes, to allow for recording
multiple aliases in a single pass. The nodes being aliased
are passed as bitset for performance reason (O(1) lookups).
It does look worse in the existing case of SetEqual where
we now need to allocate a bitset just for a single node,
but the new API will allow to fully implement a path-collapsing
primitive in next CL.

No functional changes, passes toolstash -cmp.

Change-Id: I06259610e8ef478106b36852464ed2caacd29ab5
Reviewed-on: https://go-review.googlesource.com/c/go/+/200860
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-10-26 07:16:46 +00:00
Giovanni Bajo
7e68f81dd8 cmd/compile: in poset, refactor aliasnode
In preparation for allowing to make multiple nodes as aliases
in a single pass, refactor aliasnode splitting out the case
in which one of the nodes is not in the post into a new
funciton (aliasnewnode).

No functional changes, passes toolstash -cmp

Change-Id: I19ca6ef8426f8aec9f2622b6151c5c617dbb25b5
Reviewed-on: https://go-review.googlesource.com/c/go/+/200859
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-10-26 07:06:49 +00:00
nikita-vanyasin
c3e8a20a65 cmd/link/internal: eliminate all ld.Cputime() usages
Also a similar 'elapsed' function and its usages were deleted.

Fixes #19865.

Change-Id: Ib125365e69cf2eda60de64fa74290c8c7d1fd65a
Reviewed-on: https://go-review.googlesource.com/c/go/+/171730
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
2019-10-26 05:40:14 +00:00
Ben Shi
65a1e24209 runtime: save/restore callee-save registers in arm's sigtramp
ARM's R4-R8 & R10-R11 are callee-save registers, and R9
may be callee-save or not. This CL saves them at the beginning
of sigtramp and restores them in the end.

fixes #32738

Change-Id: Ib7eb80836bc074e2e6a46ae4602ba8a3b96c5456
Reviewed-on: https://go-review.googlesource.com/c/go/+/183777
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-26 04:00:03 +00:00
Austin Clements
8dc1a158e4 runtime: add test for signalM
For #10958, #24543.

Change-Id: Ib009a83fe02bc623894f4908fe8f6b266382ba95
Reviewed-on: https://go-review.googlesource.com/c/go/+/201404
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-26 02:52:32 +00:00
Austin Clements
42aab4b0af runtime: M-targeted signals for libc-based OSes
For #10958, #24543.

Change-Id: I82bee63b49e15bd5a53228eb85179814c80437ef
Reviewed-on: https://go-review.googlesource.com/c/go/+/201403
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-26 02:52:30 +00:00
Austin Clements
8714e39497 runtime: M-targeted signals for BSDs
For these, we split up the existing runtime.raise assembly
implementation into its constituent "get thread ID" and "signal
thread" parts. This lets us implement signalM and reimplement raise in
pure Go. (NetBSD conveniently already had lwp_self.)

We also change minit to store the procid directly, rather than
depending on newosproc to do so. This is because newosproc isn't
called for the bootstrap M, but we need a procid for every M. This is
also simpler overall.

For #10958, #24543.

Change-Id: Ie5f1fcada6a33046375066bcbe054d1f784d39c0
Reviewed-on: https://go-review.googlesource.com/c/go/+/201402
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-26 02:52:28 +00:00
Austin Clements
334291d1f6 runtime: M-targeted signals for Linux
We'll add a test once all of the POSIX platforms are done.

For #10958, #24543.

Change-Id: If7e3f14e8391791364877629bf415d9f8e788b0a
Reviewed-on: https://go-review.googlesource.com/c/go/+/201401
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-26 02:52:25 +00:00
Vivek V
3706cd85d3 debug/dwarf: call strings.EqualFold instead of calling Lower twice
Change-Id: I8dcb425c37a067277549ba3bda6a21206459890a
GitHub-Last-Rev: dc51b9b425
GitHub-Pull-Request: golang/go#35132
Reviewed-on: https://go-review.googlesource.com/c/go/+/203097
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-10-26 02:36:26 +00:00
Bryan C. Mills
06bdd52f75 os: use an actual RemoveAll failure in TestRemoveAllWithMoreErrorThanReqSize
Previously we injected an error, and the injection points were
(empirically) not realistic on some platforms.

Instead, we now make the directory read-only, which (on most
platforms) suffices to prevent the removal of its files.

Fixes #35117
Updates #29921

Change-Id: Ica4e2818566f8c14df3eed7c3b8de5c0abeb6963
Reviewed-on: https://go-review.googlesource.com/c/go/+/203502
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-10-26 01:46:02 +00:00
Cuong Manh Le
66f78e9d88 runtime: mark findObject nosplit
findObject takes the pointer argument as uintptr. If the pointer is to
the local stack and calling findObject happens to require the stack to
be reallocated, then spanOf is called for the old pointer.

Marking findObject as nosplit fixes the issue.

Fixes #35068

Change-Id: I029d36f9c23f91812f18f98839edf02e0ba4082e
Reviewed-on: https://go-review.googlesource.com/c/go/+/202798
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-10-26 00:05:49 +00:00
Cuong Manh Le
813d8e8862 runtime: factor out debug.invalidptr case in findObject
This helps keeping findObject's frame small.

Updates #35068

Change-Id: I1b8c1fcc5831944c86f1a30ed2f2d867a5f2b242
Reviewed-on: https://go-review.googlesource.com/c/go/+/202797
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2019-10-26 00:05:43 +00:00
Cuong Manh Le
80315322f3 runtime: simplify findObject bad pointer checking condition
Factor out case s == nil, make the code cleaner and easier to read.

Change-Id: I63f52e14351c0a0d20a611b1fe10fdc0d4947d96
Reviewed-on: https://go-review.googlesource.com/c/go/+/202498
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2019-10-26 00:05:37 +00:00
Austin Clements
d1969015b4 runtime: abstract M preemption check into a function
We check whether an M is preemptible in a surprising number of places.
Put it in one function.

For #10958, #24543.

Change-Id: I305090fdb1ea7f7a55ffe25851c1e35012d0d06c
Reviewed-on: https://go-review.googlesource.com/c/go/+/201439
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-25 23:25:36 +00:00
Austin Clements
6058603471 runtime: only shrink stacks at synchronous safe points
We're about to introduce asynchronous safe points, where we won't have
precise pointer maps for all stack frames. That's okay for scanning
the stack (conservatively), but not for shrinking the stack.

Hence, this CL prepares for this by only shrinking the stack as part
of the stack scan if the goroutine is stopped at a synchronous safe
point. Otherwise, it queues up the stack shrink for the next
synchronous safe point.

We already have one condition under which we can't shrink the stack
for very similar reasons: syscalls. Currently, we just give up on
shrinking the stack if it's in a syscall. But with this mechanism, we
defer that stack shrink until the next synchronous safe point.

For #10958, #24543.

Change-Id: Ifa1dec6f33fdf30f9067be2ce3f7ab8a7f62ce38
Reviewed-on: https://go-review.googlesource.com/c/go/+/201438
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-25 23:25:35 +00:00
Austin Clements
36a432f27b runtime: make copystack/sudog synchronization more explicit
When we copy a stack of a goroutine blocked in a channel operation, we
have to be very careful because other goroutines may be writing to
that goroutine's stack. To handle this, stack copying acquires the
locks for the channels a goroutine is waiting on.

One complication is that stack growth may happen while a goroutine
holds these locks, in which case stack copying must *not* acquire
these locks because that would self-deadlock.

Currently, stack growth never acquires these locks because stack
growth only happens when a goroutine is running, which means it's
either not blocking on a channel or it's holding the channel locks
already. Stack shrinking always acquires these locks because shrinking
happens asynchronously, so the goroutine is never running, so there
are either no locks or they've been released by the goroutine.

However, we're about to change when stack shrinking can happen, which
is going to break the current rules. Rather than find a new way to
derive whether to acquire these locks or not, this CL simply adds a
flag to the g struct that indicates that stack copying should acquire
channel locks. This flag is set while the goroutine is blocked on a
channel op.

For #10958, #24543.

Change-Id: Ia2ac8831b1bfda98d39bb30285e144c4f7eaf9ab
Reviewed-on: https://go-review.googlesource.com/c/go/+/172982
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
2019-10-25 23:25:33 +00:00
Austin Clements
8c5861576a runtime: remove g.gcscanvalid
Currently, gcscanvalid is used to resolve a race between attempts to
scan a stack. Now that there's a clear owner of the stack scan
operation, there's no longer any danger of racing or attempting to
scan a stack more than once, so this CL eliminates gcscanvalid.

I double-checked my reasoning by first adding a throw if gcscanvalid
was set in scanstack and verifying that all.bash still passed.

For #10958, #24543.
Fixes #24363.

Change-Id: I76794a5fcda325ed7cfc2b545e2a839b8b3bc713
Reviewed-on: https://go-review.googlesource.com/c/go/+/201139
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-25 23:25:32 +00:00
Austin Clements
1b79afe460 runtime: remove old stack scanning code
This removes scang and preemptscan, since the stack scanning code now
uses suspendG.

For #10958, #24543.

Change-Id: Ic868bf5d6dcce40662a82cb27bb996cb74d0720e
Reviewed-on: https://go-review.googlesource.com/c/go/+/201138
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-25 23:25:31 +00:00
Austin Clements
3f834114ab runtime: add general suspendG/resumeG
Currently, the process of suspending a goroutine is tied to stack
scanning. In preparation for non-cooperative preemption, this CL
abstracts this into general purpose suspendG/resumeG functions.

suspendG and resumeG closely follow the existing scang and restartg
functions with one exception: the addition of a _Gpreempted status.
Currently, preemption tasks (stack scanning) are carried out by the
target goroutine if it's in _Grunning. In this new approach, the task
is always carried out by the goroutine that called suspendG. Thus, we
need a reliable way to drive the target goroutine out of _Grunning
until the requesting goroutine is ready to resume it. The new
_Gpreempted state provides the handshake: when a runnable goroutine
responds to a preemption request, it now parks itself and enters
_Gpreempted. The requesting goroutine races to put it in _Gwaiting,
which gives it ownership, but also the responsibility to start it
again.

This CL adds several TODOs about improving the synchronization on the
G status. The existing code already has these problems; we're just
taking note of them.

The next CL will remove the now-dead scang and preemptscan.

For #10958, #24543.

Change-Id: I16dbf87bea9d50399cc86719c156f48e67198f16
Reviewed-on: https://go-review.googlesource.com/c/go/+/201137
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-25 23:25:28 +00:00
pokutuna
46e0d724b3 net/http: fix comment TimeoutHandler no longer supports Flusher
Fixes #35161
Updates #34439

Change-Id: I978534cbb8b9fb32c115dba0066cf099c61d8ee9
GitHub-Last-Rev: d60581635e
GitHub-Pull-Request: golang/go#35162
Reviewed-on: https://go-review.googlesource.com/c/go/+/203478
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-10-25 20:46:57 +00:00
Bryan C. Mills
dcad830621 cmd/go: implement svn support in module mode
mod_get_svn passes, and I also tested this manually on a real-world svn-hosted package:

	example.com$ go mod init example.com
	go: creating new go.mod: module example.com

	example.com$ GOPROXY=direct GONOSUMDB=llvm.org go get -d llvm.org/llvm/bindings/go/llvm
	go: finding llvm.org/llvm latest
	go: finding llvm.org/llvm/bindings/go/llvm latest
	go: downloading llvm.org/llvm v0.0.0-20191022153947-000000375505
	go: extracting llvm.org/llvm v0.0.0-20191022153947-000000375505

	example.com$ go list llvm.org/llvm/bindings/...
	llvm.org/llvm/bindings/go
	llvm.org/llvm/bindings/go/llvm

Fixes #26092

Change-Id: Iefe2151b82a0225c73bb6f8dd7cd8a352897d4c0
Reviewed-on: https://go-review.googlesource.com/c/go/+/203497
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
2019-10-25 20:21:24 +00:00
Tobias Klauser
316fb95f4f runtime: define emptyfunc as static function in assembly for freebsd/arm64
CL 198544 broke the linux/arm64 build because it declares emptyfunc for
GOARCH=arm64, but only freebsd/arm64 defines it. Make it a static
assembly function specific for freebsd/arm64 and remove the stub.

Fixes #35160

Change-Id: I5fd94249b60c6fd259c251407b6eccc8fa512934
Reviewed-on: https://go-review.googlesource.com/c/go/+/203418
Reviewed-by: Bryan C. Mills <bcmills@google.com>
2019-10-25 20:14:52 +00:00
Bryan C. Mills
8bb47a5eec net/http: skip failing test on windows-amd64-longtest builder
bradfitz is actively thinking about a proper fix.
In the meantime, skip the test to suss out any other failures in the builder.

Updates #35122

Change-Id: I9bf0640222e3d385c1a3e2be5ab52b80d3e8c21a
Reviewed-on: https://go-review.googlesource.com/c/go/+/203500
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-10-25 18:45:21 +00:00
Bryan C. Mills
096126de6b os/signal: derive TestAtomicStop timeout from overall test timeout
Previously, TestAtomicStop used a hard-coded 2-second timeout.

That empirically is not long enough on certain builders. Rather than
adjusting it to a different arbitrary value, use a slice of the
overall timeout for the test binary. If everything is working, we
won't block nearly that long anyway.

Updates #35085

Change-Id: I7b789388e3152413395088088fc497419976cf5c
Reviewed-on: https://go-review.googlesource.com/c/go/+/203499
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-10-25 18:44:06 +00:00
Tobias Klauser
3d457f1a36 cmd/dist: add support for freebsd/arm64
Updates #24715

Change-Id: I110a10a5d5ed4a471f67f35cbcdcbea296c5dcaf
Reviewed-on: https://go-review.googlesource.com/c/go/+/198542
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-10-25 17:59:32 +00:00
Tobias Klauser
6b6e67f9b9 runtime: add support for freebsd/arm64
Based on work by Mikaël Urankar (@MikaelUrankar),
Shigeru YAMAMOTO (@bsd-hacker) and @myfreeweb.

Updates #24715

Change-Id: If3189a693ca0aa627029e22b0f91534bcf322bc0
Reviewed-on: https://go-review.googlesource.com/c/go/+/198544
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-10-25 17:59:05 +00:00
Austin Clements
fc8eb264bb runtime: ensure _Grunning Gs have a valid g.m and g.m.p
We already claim on the documentation for _Grunning that this is case,
but execute transitions to _Grunning before assigning g.m. Fix this
and make the documentation even more explicit.

For #10958, #24543, but also a good cleanup.

Change-Id: I1eb0108e7762f55cfb0282aca624af1c0a15fe56
Reviewed-on: https://go-review.googlesource.com/c/go/+/201440
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-25 16:59:39 +00:00
Austin Clements
f82956b85b runtime: make m.libcallsp check in shrinkstack panic
Currently, shrinkstack will not shrink a stack on Windows if
gp.m.libcallsp != 0. In general, we can't shrink stacks in syscalls
because the syscall may hold pointers into the stack, and in principle
this is supposed to be preventing that for libcall-based syscalls
(which are direct syscalls from the runtime). But this test is
actually broken and has been for a long time. That turns out to be
okay because it also appears it's not necessary.

This test is racy. g.m points to whatever M the G was last running on,
even if the G is in a blocked state, and that M could be doing
anything, including making libcalls. Hence, observing that libcallsp
== 0 at one moment in shrinkstack is no guarantee that it won't become
non-zero while we're shrinking the stack, and vice-versa.

It's also weird that this check is only performed on Windows, given
that we now use libcalls on macOS, Solaris, and AIX.

This check was added when stack shrinking was first implemented in CL
69580044. The history of that CL (though not the final version)
suggests this was necessary for libcalls that happened on Go user
stacks, which we never do now because of the limited stack space.

It could also be defending against user stack pointers passed to
libcall system calls from blocked Gs. But the runtime isn't allowed to
keep pointers into the user stack for blocked Gs on any OS, so it's
not clear this would be of any value.

Hence, this checks seems to be simply unnecessary.

Rather than simply remove it, this CL makes it defensive. We can't do
anything about blocked Gs, since it doesn't even make sense to look at
their M, but if a G tries to shrink its own stack while in a libcall,
that indicates a bug in the libcall code. This CL makes shrinkstack
panic in this case.

For #10958, #24543, since those are going to rearrange how we decide
that it's safe to shrink a stack.

Change-Id: Ia865e1f6340cff26637f8d513970f9ebb4735c6d
Reviewed-on: https://go-review.googlesource.com/c/go/+/173724
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-25 16:59:36 +00:00
Austin Clements
9d032026d6 cmd/internal/obj/x86: correct pcsp for ADJSP
The x86 assembler supports an "ADJSP" pseudo-op that compiles to an
ADD/SUB from SP. Unfortunately, while this seems perfect for an
instruction that would allow obj to continue to track the SP/FP delta,
obj currently doesn't do that. As a result, FP-relative references
won't work and, perhaps worse, the pcsp table will have the wrong
frame size.

We don't currently use this instruction in any assembly or generate it
in the compiler, but this is a perfect instruction for solving a
problem in #24543.

This CL makes ADJSP useful by incorporating it into the SP delta
logic.

One subtlety is that we do generate ADJSP in obj itself to open a
function's stack frame. Currently, when preprocess enters the loop to
compute the SP delta, it may or may not start at this ADJSP
instruction depending on various factors. We clean this up by instead
always starting the SP delta at 0 and always starting this loop at the
entry to the function.

Why not just recognize ADD/SUB of SP? The danger is that could change
the meaning of existing code. For example, walltime1 in
sys_linux_amd64.s saves SP, SUBs from it, and aligns it. Later, it
restores the saved copy and then does a few FP-relative references.
Currently obj doesn't know any of this is happening, but that's fine
once it gets to the FP-relative references. If we taught obj to
recognize the SUB, it would start to miscompile this code. An
alternative would be to recognize unknown instructions that write to
SP and refuse subsequent FP-relative references, but that's kind of
annoying.

This passes toolstash -cmp for std on both amd64 and 386.

Change-Id: Ic6c6a7cbf980bca904576676c07b44c0aaa9c82d
Reviewed-on: https://go-review.googlesource.com/c/go/+/200877
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2019-10-25 16:34:10 +00:00
ZYunH
00d6b28d4e internal/singleflight: format someErr
Error string should not be capitalized.

Change-Id: I8e1d148c6b999450bcd702f420c2a240f82aadc7
GitHub-Last-Rev: 6ca1b3edb4
GitHub-Pull-Request: golang/go#35147
Reviewed-on: https://go-review.googlesource.com/c/go/+/203339
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-10-25 16:31:41 +00:00
Meng Zhuo
dad512f6df cmd/dist: fix wrong goarch on mips64le
Change-Id: I625f0bc533a7d14010c0344f36e8f157a19c13f2
Reviewed-on: https://go-review.googlesource.com/c/go/+/203437
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
2019-10-25 14:31:54 +00:00
Meng Zhuo
9a701017e6 runtime: fix typo of MADV_NOHUGEPAGE
Change-Id: I60a1ca606fe7492c05697c4d58afc7f19fcc63fe
Reviewed-on: https://go-review.googlesource.com/c/go/+/203340
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-10-25 13:49:01 +00:00
Jason A. Donenfeld
3c25e5ec38 internal/syscall/windows/registry: allow for non-null terminated strings
According to MSDN, "If the data has the REG_SZ, REG_MULTI_SZ or
REG_EXPAND_SZ type, this size includes any terminating null character or
characters unless the data was stored without them. [...] If the data
has the REG_SZ, REG_MULTI_SZ or REG_EXPAND_SZ type, the string may not
have been stored with the proper terminating null characters. Therefore,
even if the function returns ERROR_SUCCESS, the application should
ensure that the string is properly terminated before using it;
otherwise, it may overwrite a buffer."

It's therefore dangerous to pass it off unbounded as we do, and in fact
this led to crashes on real systems.

Change-Id: I6d786211814656f036b87fd78631466634cd764a
Reviewed-on: https://go-review.googlesource.com/c/go/+/202937
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
2019-10-25 09:01:11 +00:00
Rob Pike
4f70c151db fmt: fix handling of %% verb in Scanf
There were a couple of bugs, including not requiring a percent and
returning the wrong error for a bad format containing %%.

Both are addressed by fixing the first.

Fixes #34180.

Change-Id: If96c0c0258bcb95eec49871437d719cb9d399d9b
Reviewed-on: https://go-review.googlesource.com/c/go/+/202879
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2019-10-25 04:15:59 +00:00
Rémy Oudompheng
8f30d25168 math/big: use nat pool to reduce allocations in mul and sqr
This notably allows to reuse temporaries across
the karatsubaSqr recursion.

benchmark                    old ns/op     new ns/op     delta
BenchmarkNatMul/10-4         227           228           +0.44%
BenchmarkNatMul/100-4        8339          8589          +3.00%
BenchmarkNatMul/1000-4       313796        312272        -0.49%
BenchmarkNatMul/10000-4      11924720      11873589      -0.43%
BenchmarkNatMul/100000-4     503813354     503839058     +0.01%
BenchmarkNatSqr/20-4         549           513           -6.56%
BenchmarkNatSqr/30-4         945           874           -7.51%
BenchmarkNatSqr/50-4         1993          1832          -8.08%
BenchmarkNatSqr/80-4         4096          3874          -5.42%
BenchmarkNatSqr/100-4        6192          5712          -7.75%
BenchmarkNatSqr/200-4        20388         19543         -4.14%
BenchmarkNatSqr/300-4        38735         36715         -5.21%
BenchmarkNatSqr/500-4        99562         93542         -6.05%
BenchmarkNatSqr/800-4        195554        184907        -5.44%
BenchmarkNatSqr/1000-4       286302        275053        -3.93%
BenchmarkNatSqr/10000-4      9817057       9441641       -3.82%
BenchmarkNatSqr/100000-4     390713416     379696789     -2.82%

benchmark                    old allocs     new allocs     delta
BenchmarkNatMul/10-4         1              1              +0.00%
BenchmarkNatMul/100-4        1              1              +0.00%
BenchmarkNatMul/1000-4       2              1              -50.00%
BenchmarkNatMul/10000-4      2              1              -50.00%
BenchmarkNatMul/100000-4     9              11             +22.22%
BenchmarkNatSqr/20-4         2              1              -50.00%
BenchmarkNatSqr/30-4         2              1              -50.00%
BenchmarkNatSqr/50-4         2              1              -50.00%
BenchmarkNatSqr/80-4         2              1              -50.00%
BenchmarkNatSqr/100-4        2              1              -50.00%
BenchmarkNatSqr/200-4        2              1              -50.00%
BenchmarkNatSqr/300-4        4              1              -75.00%
BenchmarkNatSqr/500-4        4              1              -75.00%
BenchmarkNatSqr/800-4        10             1              -90.00%
BenchmarkNatSqr/1000-4       10             1              -90.00%
BenchmarkNatSqr/10000-4      731            1              -99.86%
BenchmarkNatSqr/100000-4     19687          6              -99.97%

benchmark                    old bytes     new bytes     delta
BenchmarkNatMul/10-4         192           192           +0.00%
BenchmarkNatMul/100-4        4864          4864          +0.00%
BenchmarkNatMul/1000-4       57344         49224         -14.16%
BenchmarkNatMul/10000-4      565248        498772        -11.76%
BenchmarkNatMul/100000-4     5749504       7263720       +26.34%
BenchmarkNatSqr/20-4         672           352           -47.62%
BenchmarkNatSqr/30-4         992           512           -48.39%
BenchmarkNatSqr/50-4         1792          896           -50.00%
BenchmarkNatSqr/80-4         2688          1408          -47.62%
BenchmarkNatSqr/100-4        3584          1792          -50.00%
BenchmarkNatSqr/200-4        6656          3456          -48.08%
BenchmarkNatSqr/300-4        24448         16387         -32.97%
BenchmarkNatSqr/500-4        36864         24591         -33.29%
BenchmarkNatSqr/800-4        69760         40981         -41.25%
BenchmarkNatSqr/1000-4       86016         49180         -42.82%
BenchmarkNatSqr/10000-4      2524800       487368        -80.70%
BenchmarkNatSqr/100000-4     68599808      5876581       -91.43%

Change-Id: I8e6e409ae1cb48be9d5aa9b5f428d6cbe487673a
Reviewed-on: https://go-review.googlesource.com/c/go/+/172017
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2019-10-25 03:14:39 +00:00
Bryan C. Mills
680ed10c91 cmd/go/internal/modfetch/codehost: remove invariantly-empty return value from Repo.ReadZip
Previously, codehost.Repo.ReadZip returned an 'actualSubdir' value
that was the empty string in all current implementations.

Updates #26092

Change-Id: I6708dd0f13ba88bcf1a1fb405e9d818fd6f9197e
Reviewed-on: https://go-review.googlesource.com/c/go/+/203277
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
2019-10-24 20:19:06 +00:00
Jay Conrod
c357b363cf cmd/go: add -modfile flag that sets go.mod file to read/write
This change adds the -modfile flag to module aware build commands and
to 'go mod' subcommands. -modfile may be set to a path to an alternate
go.mod file to be read and written. A real go.mod file must still
exist and is used to set the module root directory. However, it is not
opened.

When -modfile is set, the effective location of the go.sum file is
also changed to the -modfile with the ".mod" suffix trimmed (if
present) and ".sum" added.

Updates #34506

Change-Id: I2d1e044e18af55505a4f24bbff09b73bb9c908b4
Reviewed-on: https://go-review.googlesource.com/c/go/+/202564
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
2019-10-24 20:15:50 +00:00