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24636 Commits

Author SHA1 Message Date
MathiasB
bd1efd5099 net/mail: fixed quoted-local
Fixes some minor issues regarding quoted-string when parsing
the local-part.

Those strings should return an error:
- quoted-string without any content: `""@test.com`
- quoted-string containing tab: "\"\t\"@test.com"

Fixes #11293

Change-Id: Ied93eb6831915c9b1f8e727cea14168af21f8d3b
Reviewed-on: https://go-review.googlesource.com/12905
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-31 16:11:21 +00:00
Russ Cox
782eea0190 cmd/internal/obj/arm: fix large stack offsets on nacl/arm
The code already fixed large non-stack offsets
but explicitly excluded stack references.
Perhaps you could get away with that before,
but current versions of nacl reject such stack
references. Rewrite them the same as the others.

For #11956 but probably not the last problem.

Change-Id: I0db4e3a1ed4f88ccddf0d30228982960091d9fb7
Reviewed-on: https://go-review.googlesource.com/13010
Reviewed-by: Dave Cheney <dave@cheney.net>
2015-07-31 04:35:48 +00:00
Russ Cox
108ec5f75a runtime: fix systemstack tracebacks on nacl/arm
For #11956.

Change-Id: Ic9b57cafa197953cc7f435941e44d42b60b3ddf0
Reviewed-on: https://go-review.googlesource.com/13011
Reviewed-by: Dave Cheney <dave@cheney.net>
2015-07-31 04:35:38 +00:00
Andrew Gerrand
b63fb59de8 test/bench/shootout: clean up binaries after run
Update #11943

Change-Id: I3e6592876bf16d2f9129995b723ecf69c069653d
Reviewed-on: https://go-review.googlesource.com/12913
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-31 02:50:43 +00:00
Russ Cox
abdc77a288 runtime: avoid reference to stale stack after GC shrinkstack
Dangling pointer error. Unlikely to trigger in practice, but still.
Found by running GODEBUG=efence=1 GOGC=1 trace.test.

Change-Id: Ice474dedcf62dd33ab77526287a023ba3b166db9
Reviewed-on: https://go-review.googlesource.com/12991
Reviewed-by: Austin Clements <austin@google.com>
2015-07-31 02:18:42 +00:00
Russ Cox
66cb5cd530 cmd/link: increase ELFRESERVE to a full page
Etcd and kubernetes have hit this.
See  https://bugzilla.redhat.com/show_bug.cgi?id=1248071

Change-Id: I6231013efa0a19ee74f7ebacd1024adb368af83a
Reviewed-on: https://go-review.googlesource.com/12951
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-07-31 02:18:35 +00:00
Ian Lance Taylor
3548a1e7b8 cmd/go: permit installing into a subdirectory of $GOPATH/bin
In https://golang.org/cl/12080 we forbade installing cross-compiled
binaries into a subdirectory of $GOBIN, in order to fix
https://golang.org/issue/9769.  However, that fix was too aggressive,
in that it also forbade installing into a subdirectory of $GOPATH/bin.

This patch permits installing cross-compiled binaries into a
subdirectory $GOPATH/bin while continuing to forbid installing into a
subdirectory of $GOBIN.

Fixes #11778.

Change-Id: Ibc9919554e8c275beff54ec8bf919cfaa03b11ba
Reviewed-on: https://go-review.googlesource.com/12938
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-31 00:37:44 +00:00
Rob Pike
4e0be154f7 doc: solaris info added to go1.5.html
Fixes #11952.

Change-Id: I548f9d75c6223bf79bdf654ef733f1568e3d5804
Reviewed-on: https://go-review.googlesource.com/12990
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-07-31 00:18:02 +00:00
Robert Griesemer
2d9378c7f6 spec: document existing expression switch restrictions
The spec didn't specify several aspects of expression switches:

- The switch expression is evaluated exactly once.

- Switch expressions evaluating to an untyped value are converted
  to the respective default type before use.

- An (untyped) nil value is not permitted as expression switch
  value. (We could permit it relatively easily, but gc doesn't,
  and disallowing it is in symmetry with the rules for var decls
  without explicit type and untyped initializer expressions.)

- The comparison x == t between each case expression x and
  switch expression value t must be valid.

- (Some) duplicate constant case expressions are not permitted.

This change also clarifies the following issues:

 4524: mult. equal int const switch case values should be illegal
                                         -> spec issue fixed
 6398: switch w/ no value uses bool rather than untyped bool
                                         -> spec issue fixed
11578: allows duplicate switch cases     -> go/types bug
11667: int overflow in switch expression -> go/types bug
11668: use of untyped nil in switch      -> not a gc bug

Fixes #4524.
Fixes #6398.
Fixes #11668.

Change-Id: Iae4ab3e714575a5d11c92c9b8fbf027aa706b370
Reviewed-on: https://go-review.googlesource.com/12711
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
2015-07-30 23:11:20 +00:00
Rob Pike
f4c775eb70 doc: in go1.5.html fix claim about linking for ppc64(le)?
Change-Id: If61c2063a8b63f0e3e498a5e86803b5ddba9fa3c
Reviewed-on: https://go-review.googlesource.com/12886
Reviewed-by: Austin Clements <austin@google.com>
2015-07-30 22:54:49 +00:00
Brad Fitzpatrick
2ae3581639 A+C: automated update
Change-Id: Ie4431e74f095b85b4b5c07d087c3d29acf46d138
Reviewed-on: https://go-review.googlesource.com/12902
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-07-30 21:35:23 +00:00
Brad Fitzpatrick
0e00b447a5 api: update go1.5.txt
Fixes #11935

Change-Id: Ife00c246345f7d3f96aa95349a35e76671ca7160
Reviewed-on: https://go-review.googlesource.com/12769
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-30 21:14:09 +00:00
Russ Cox
ca6f7e45cb runtime/trace: report negative frequency as a time-ordering problem
This should fix the solaris/amd64 builder.

Change-Id: Idd6460cc9e842f7b874c9757379986aa723c974c
Reviewed-on: https://go-review.googlesource.com/12922
Reviewed-by: Austin Clements <austin@google.com>
2015-07-30 20:32:01 +00:00
Dave Cheney
4e15092006 syscall: use fchownat(2) in place of lchown(2) for linux/arm64
Fixes #11918

Replace calls to lchown(2) with fchownat(2) for linux/arm64 as the former is not suppored.

This change has also landed on the x/sys repo as CL 12837.

Change-Id: I58d4b144e051e36dd650ec9b7f3a02610ea943e5
Reviewed-on: https://go-review.googlesource.com/12833
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
Run-TryBot: Dave Cheney <dave@cheney.net>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-30 20:30:26 +00:00
Ian Lance Taylor
a5d23fceab doc: add go1.5 note about change to zero-sized fields in cgo
This documents the change made in https://golang.org/cl/12864 for
https://golang.org/issue/11925.

Update #11925.

Change-Id: Id09f2a489ea947a725ed12c9cf793e5daef07a06
Reviewed-on: https://go-review.googlesource.com/12866
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-07-30 20:12:06 +00:00
Russ Cox
4bd8040d47 runtime, sync/atomic: add memory barriers in arm cas routines
This only triggers on ARMv7+.
If there are important SMP ARMv6 machines we can reconsider.

Makes TestLFStress tests pass and sync/atomic tests not time out
on Apple iPad Mini 3.

Fixes #7977.
Fixes #10189.

Change-Id: Ie424dea3765176a377d39746be9aa8265d11bec4
Reviewed-on: https://go-review.googlesource.com/12950
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-07-30 20:11:11 +00:00
Robert Griesemer
87fd98d220 go/types: update comment to refer to package go/constant
For #11949.

Change-Id: I4329604a24efc7f40cf5bf52fb3c9e30916b3cc2
Reviewed-on: https://go-review.googlesource.com/12931
Reviewed-by: Alan Donovan <adonovan@google.com>
2015-07-30 20:06:49 +00:00
Russ Cox
80e6d638bf encoding/json: revert "fix decoding of JSON null values"
Fixes #11912.
Fixes #11937.

This reverts commit 1a99ba55df.

Change-Id: I32b76053fdabc59f28ca5bedf1b15c0baa8afae1
Reviewed-on: https://go-review.googlesource.com/12893
Reviewed-by: Didier Spezia <didier.06@gmail.com>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-07-30 20:00:56 +00:00
Russ Cox
e0c180c44f runtime/cgo: fix darwin/amd64 signal handling setup
Was not allocating space for the frame above sigpanic,
nor was it pushing the LR into the right place.
Because traceback past sigpanic only needs the
LR for faulting leaves, this was not noticed too much.
But it did break the sync/atomic nil deref tests.

Change-Id: Icba53fffa193423aab744c37f21ee893ce2ee3ac
Reviewed-on: https://go-review.googlesource.com/12926
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-07-30 19:18:45 +00:00
David Chase
6f6bcadc17 cmd/compile: add case for ODOTTYPE to escwalk
ODOTTYPE should be treated a whole lot like ODOT,
but it was missing completely from the switch in
escwalk and thus escape status did not propagate
to fields.

Since interfaces are required to trigger this bug,
the test was added to escape_iface.go.

Fixes #11931.

Change-Id: Id0383981cc4b1a160f6ad447192a112eed084538
Reviewed-on: https://go-review.googlesource.com/12921
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-30 17:39:44 +00:00
Russ Cox
0bd8de1048 sync/atomic: reenable TestNilDeref everywhere
There is absolutely no information about how this was failing.
If we reenable the test then at least we can get a build log from
darwin/arm.

There are not even freebsd/arm or netbsd/arm builders,
so not too worried about those. (That is another problem.)

Change-Id: I0e739a4dd2897adbe110aa400d720d8fa02ae65f
Reviewed-on: https://go-review.googlesource.com/12920
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-30 16:38:29 +00:00
Russ Cox
b2dfacf35e runtime: change arm software div/mod call sequence not to modify stack
Instead of pushing the denominator argument on the stack,
the denominator is now passed in m.

This fixes a variety of bugs related to trying to take stack traces
backwards from the middle of the software div/mod routines.
Some of those bugs have been kludged around in the past,
but others have not. Instead of trying to patch up after breaking
the stack, this CL stops breaking the stack.

This is an update of https://golang.org/cl/19810043,
which was rolled back in https://golang.org/cl/20350043.

The problem in the original CL was that there were divisions
at bad times, when m was not available. These were divisions
by constant denominators, either in C code or in assembly.
The Go compiler knows how to generate division by multiplication
for constant denominators, but the C compiler did not.
There is no longer any C code, so that's taken care of.
There was one problematic DIV in runtime.usleep (assembly)
but https://golang.org/cl/12898 took care of that one.
So now this approach is safe.

Reject DIV/MOD in NOSPLIT functions to keep them from
coming back.

Fixes #6681.
Fixes #6699.
Fixes #10486.

Change-Id: I09a13c76ad08ba75b3bd5d46a3eb78e66a84ab38
Reviewed-on: https://go-review.googlesource.com/12899
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-07-30 16:14:05 +00:00
Ian Lance Taylor
7904946eeb cmd/cgo: discard trailing zero-sized fields in a non-empty C struct
In order to fix issue #9401 the compiler was changed to add a padding
byte to any non-empty Go struct that ends in a zero-sized field.  That
causes the Go version of such a C struct to have a different size than
the C struct, which can considerable confusion.  Change cgo so that it
discards any such zero-sized fields, so that the Go and C structs are
the same size.

This is a change from previous releases, in that it used to be
possible to refer to a zero-sized trailing field (by taking its
address), and with this change it no longer is.  That is unfortunate,
but something has to change.  It seems better to visibly break
programs that do this rather than to silently break programs that rely
on the struct sizes being the same.

Update #9401.
Fixes #11925.

Change-Id: I3fba3f02f11265b3c41d68616f79dedb05b81225
Reviewed-on: https://go-review.googlesource.com/12864
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-30 15:55:25 +00:00
Russ Cox
c9d2c7f0d2 runtime: replace divide with multiply in runtime.usleep on arm
We want to adjust the DIV calling convention to use m,
and usleep can be called without an m, so switch to a
multiplication by the reciprocal (and test).

Step toward a fix for #6699 and #10486.

Change-Id: Iccf76a18432d835e48ec64a2fa34a0e4d6d4b955
Reviewed-on: https://go-review.googlesource.com/12898
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-07-30 15:48:29 +00:00
Russ Cox
a1e422071c cmd/internal/obj/arm: fix line numbers after constant pool
If a function is large enough to need to flush the constant pool
mid-function, the line number assignment code was forcing the
line numbers not just for the constant pool but for all the instructions
that follow it. This made the line number information completely
wrong for all but the beginning of large functions on arm.

Same problem in code copied into arm64.

This broke runtime/trace's TestTraceSymbolize.

Fixes arm build.

Change-Id: I84d9fb2c798c4085f69b68dc766ab4800c7a6ca4
Reviewed-on: https://go-review.googlesource.com/12894
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
2015-07-30 15:47:31 +00:00
Russ Cox
ab714a70dc crypto/x509: mark root_darwin_armx.go as cgo-only
This allows running a cross-compile like
	GOOS=darwin GOARCH=arm go build std
to check that everything builds.

Otherwise there is a redefinition error because both
root_nocgo_darwin.go and root_darwin_armx.go
supply initSystemRoots.

Change-Id: Ic95976b2b698d28c629bfc93d8dac0048b023578
Reviewed-on: https://go-review.googlesource.com/12897
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-07-30 15:47:16 +00:00
Russ Cox
48b4263efa net: allow longer timeout in dialClosedPort test on windows
The test expects the dial to take 1.0 seconds
on Windows and allows it to go to 1.095 seconds.
That's far too optimistic.
Recent failures are reporting roughly 1.2 seconds.
Let it have 1.5.

Change-Id: Id69811ccb65bf4b4c159301a2b4767deb6ee8d28
Reviewed-on: https://go-review.googlesource.com/12895
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-07-30 15:19:17 +00:00
Andrey Petrov
7cabaded51 math/rand: warn against using package for security-sensitive work
Urge users of math/rand to consider using crypto/rand when doing
security-sensitive work.

Related to issue #11871. While we haven't reached consensus on how
to make the package inherently safer, everyone agrees that the docs
for math/rand can be improved.

Change-Id: I576a312e51b2a3445691da6b277c7b4717173197
Reviewed-on: https://go-review.googlesource.com/12900
Reviewed-by: Rob Pike <r@golang.org>
2015-07-30 12:42:18 +00:00
David Crawshaw
b7205b92c0 runtime/trace: test requires 'go tool addr2line'
For the android/arm builder.

Change-Id: Iad4881689223cd6479870da9541524a8cc458cce
Reviewed-on: https://go-review.googlesource.com/12859
Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
2015-07-30 05:57:37 +00:00
Russ Cox
c4092ac398 cmd/compile: fix uninitialized memory during type switch assertE2I2
Fixes arm64 builder crash.

The bug is possible on all architectures; you just have to get lucky
and hit a preemption or a stack growth on entry to assertE2I2.
The test stacks the deck.

Change-Id: I8419da909b06249b1ad15830cbb64e386b6aa5f6
Reviewed-on: https://go-review.googlesource.com/12890
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
2015-07-30 05:21:56 +00:00
Russ Cox
bfac8623d5 runtime: enable TestEmptySlice
It says to disable until #7564 is fixed. It was fixed in April 2014.

Change-Id: I9bebfe96802bafdd2d1a0a47591df346d91b000c
Reviewed-on: https://go-review.googlesource.com/12858
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-07-30 04:47:16 +00:00
Russ Cox
d3ffc975f3 runtime: set invalidptr=1 by default, as documented
Also make invalidptr control the recently added GC pointer check,
as documented.

Change-Id: Iccfdf49480219d12be8b33b8f03d8312d8ceabed
Reviewed-on: https://go-review.googlesource.com/12857
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
2015-07-29 23:50:20 +00:00
Andrew Gerrand
e4bd8e0408 doc: remove non-answer from FAQ
Change-Id: Ie43986d016e5a9fb17ca1393263932bbb56e81ff
Reviewed-on: https://go-review.googlesource.com/12836
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-29 23:01:10 +00:00
Russ Cox
bd5ca22232 runtime/trace: remove existing Skips
The skips added in CL 12579, based on incorrect time stamps,
should be sufficient to identify and exclude all the time-related
flakiness on these systems.

If there is other flakiness, we want to find out.

For #10512.

Change-Id: I5b588ac1585b2e9d1d18143520d2d51686b563e3
Reviewed-on: https://go-review.googlesource.com/12746
Reviewed-by: Austin Clements <austin@google.com>
2015-07-29 22:32:23 +00:00
Russ Cox
80c98fa901 runtime/trace: record event sequence numbers explicitly
Nearly all the flaky failures we've seen in trace tests have been
due to the use of time stamps to determine relative event ordering.
This is tricky for many reasons, including:
 - different cores might not have exactly synchronized clocks
 - VMs are worse than real hardware
 - non-x86 chips have different timer resolution than x86 chips
 - on fast systems two events can end up with the same time stamp

Stop trying to make time reliable. It's clearly not going to be for Go 1.5.
Instead, record an explicit event sequence number for ordering.
Using our own counter solves all of the above problems.

The trace still contains time stamps, of course. The sequence number
is just used for ordering.

Should alleviate #10554 somewhat. Then tickDiv can be chosen to
be a useful time unit instead of having to be exact for ordering.

Separating ordering and time stamps lets the trace parser diagnose
systems where the time stamp order and actual order do not match
for one reason or another. This CL adds that check to the end of
trace.Parse, after all other sequence order-based checking.
If that error is found, we skip the test instead of failing it.
Putting the check in trace.Parse means that cmd/trace will pick
up the same check, refusing to display a trace where the time stamps
do not match actual ordering.

Using net/http's BenchmarkClientServerParallel4 on various CPU counts,
not tracing vs tracing:

name                      old time/op    new time/op    delta
ClientServerParallel4       50.4µs ± 4%    80.2µs ± 4%  +59.06%        (p=0.000 n=10+10)
ClientServerParallel4-2     33.1µs ± 7%    57.8µs ± 5%  +74.53%        (p=0.000 n=10+10)
ClientServerParallel4-4     18.5µs ± 4%    32.6µs ± 3%  +75.77%        (p=0.000 n=10+10)
ClientServerParallel4-6     12.9µs ± 5%    24.4µs ± 2%  +89.33%        (p=0.000 n=10+10)
ClientServerParallel4-8     11.4µs ± 6%    21.0µs ± 3%  +83.40%        (p=0.000 n=10+10)
ClientServerParallel4-12    14.4µs ± 4%    23.8µs ± 4%  +65.67%        (p=0.000 n=10+10)

Fixes #10512.

Change-Id: I173eecf8191e86feefd728a5aad25bf1bc094b12
Reviewed-on: https://go-review.googlesource.com/12579
Reviewed-by: Austin Clements <austin@google.com>
2015-07-29 22:32:14 +00:00
Russ Cox
fde392623a runtime: ignore arguments in cgocallback_gofunc frame
Otherwise the GC may see uninitialized memory there,
which might be old pointers that are retained, or it might
trigger the invalid pointer check.

Fixes #11907.

Change-Id: I67e306384a68468eef45da1a8eb5c9df216a77c0
Reviewed-on: https://go-review.googlesource.com/12852
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2015-07-29 22:30:46 +00:00
Russ Cox
f6dfe16798 runtime: fix darwin/amd64 assembly frame sizes
Change-Id: I2f0ecdc02ce275feadf07e402b54f988513e9b49
Reviewed-on: https://go-review.googlesource.com/12855
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-29 22:26:02 +00:00
Russ Cox
c1ccbab097 cmd/internal/obj/arm64: fix build
Change-Id: I3088e17aff72096e3ec2ced49c70564627c982a6
Reviewed-on: https://go-review.googlesource.com/12854
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-29 21:44:27 +00:00
Russ Cox
4addec3aaa runtime: reenable bad pointer check in GC
The last time we tried this, linux/arm64 broke.
The series of CLs leading to this one fixes that problem.
Let's try again.

Fixes #9880.

Change-Id: I67bc1d959175ec972d4dcbe4aa6f153790f74251
Reviewed-on: https://go-review.googlesource.com/12849
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2015-07-29 21:37:55 +00:00
Russ Cox
034a10d44c cmd/internal/obj/arm64: reject misaligned stack frames, except empty frames
The layout code has to date insisted on stack frames that are 16-aligned
including the saved LR, and it ensured this by growing the frame itself.
This breaks code that refers to values near the top of the frame by positive
offset from SP, and in general it's too magical: if you see TEXT xxx, $N,
you expect that the frame size is actually N, not sometimes N and sometimes N+8.

This led to a serious bug in the compiler where ambiguously live values
were not being zeroed correctly, which in turn triggered an assertion
in the GC about finding only valid pointers. The compiler has been
fixed to always emit aligned frames, and the hand-written assembly
has also been fixed.

Now that everything is aligned, make unaligned an error instead of
something to "fix" silently.

For #9880.

Change-Id: I05f01a9df174d64b37fa19b36a6b6c5f18d5ba2d
Reviewed-on: https://go-review.googlesource.com/12848
Reviewed-by: Austin Clements <austin@google.com>
2015-07-29 21:37:12 +00:00
Russ Cox
767e065809 cmd/link: fix nosplit stack overflow checks
The nosplit stack overflow checks were confused about morestack.
The comment about not having correct SP information at the call
to morestack was true, but that was a real bug, not something to
work around. I fixed that problem in CL 12144. With that fixed,
no need to special-case morestack in the way done here.

This cleanup and simplification of the code was the first step
to fixing a bug that happened when I started working on the
arm64 frame size adjustments, but the cleanup was sufficient
to make the bug go away.

For #9880.

Change-Id: I16b69a5c16b6b8cb4090295d3029c42d606e3b9b
Reviewed-on: https://go-review.googlesource.com/12846
Reviewed-by: Austin Clements <austin@google.com>
2015-07-29 21:36:16 +00:00
Russ Cox
421220571d runtime, reflect: use correctly aligned stack frame sizes on arm64
arm64 requires either no stack frame or a frame with a size that is 8 mod 16
(adding the saved LR will make it 16-aligned).

The cmd/internal/obj/arm64 has been silently aligning frames, but it led to
a terrible bug when the compiler and obj disagreed on the frame size,
and it's just generally confusing, so we're going to make misaligned frames
an error instead of something that is silently changed.

This CL prepares by updating assembly files.
Note that the changes in this CL are already being done silently by
cmd/internal/obj/arm64, so there is no semantic effect here,
just a clarity effect.

For #9880.

Change-Id: Ibd6928dc5fdcd896c2bacd0291bf26b364591e28
Reviewed-on: https://go-review.googlesource.com/12845
Reviewed-by: Austin Clements <austin@google.com>
2015-07-29 21:35:35 +00:00
Russ Cox
3952057cf6 cmd/compile: align arm64 stack frames correctly
If the compiler doesn't do it, cmd/internal/obj/arm64 will,
and that will break the zeroing of ambiguously live values
done in zerorange, which in turn produces uninitialized
pointer cells that the GC trips over.

For #9880.

Change-Id: Ice97c30bc8b36d06b7b88d778d87fab8e1827fdc
Reviewed-on: https://go-review.googlesource.com/12847
Reviewed-by: Austin Clements <austin@google.com>
2015-07-29 21:34:50 +00:00
Austin Clements
23e4744c07 runtime: report GC CPU utilization in MemStats
This adds a GCCPUFraction field to MemStats that reports the
cumulative fraction of the program's execution time spent in the
garbage collector. This is equivalent to the utilization percent shown
in the gctrace output and makes this available programmatically.

This does make one small effect on the gctrace output: we now report
the duration of mark termination up to just before the final
start-the-world, rather than up to just after. However, unlike
stop-the-world, I don't believe there's any way that start-the-world
can block, so it should take negligible time.

While there are many statistics one might want to expose via MemStats,
this is one of the few that will undoubtedly remain meaningful
regardless of future changes to the memory system.

The diff for this change is larger than the actual change. Mostly it
lifts the code for computing the GC CPU utilization out of the
debug.gctrace path.

Updates #10323.

Change-Id: I0f7dc3fdcafe95e8d1233ceb79de606b48acd989
Reviewed-on: https://go-review.googlesource.com/12844
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-29 20:23:34 +00:00
Austin Clements
4b71660c5b runtime: always capture GC phase transition times
Currently we only capture GC phase transition times if
debug.gctrace>0, but we're about to compute GC CPU utilization
regardless of whether debug.gctrace is set, so we need these
regardless of debug.gctrace.

Change-Id: If3acf16505a43d416e9a99753206f03287180660
Reviewed-on: https://go-review.googlesource.com/12843
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
2015-07-29 20:23:25 +00:00
Austin Clements
87f97c73d3 runtime: avoid race between SIGPROF traceback and stack barriers
The following sequence of events can lead to the runtime attempting an
out-of-bounds access on a stack barrier slice:

1. A SIGPROF comes in on a thread while the G on that thread is in
   _Gsyscall. The sigprof handler calls gentraceback, which saves a
   local copy of the G's stkbar slice. Currently the G has no stack
   barriers, so this slice is empty.

2. On another thread, the GC concurrently scans the stack of the
   goroutine being profiled (it considers it stopped because it's in
   _Gsyscall) and installs stack barriers.

3. Back on the sigprof thread, gentraceback comes across a stack
   barrier in the stack and attempts to look it up in its (zero
   length) copy of G's old stkbar slice, which causes an out-of-bounds
   access.

This commit fixes this by adding a simple cas spin to synchronize the
SIGPROF handler with stack barrier insertion.

In general I would prefer that this synchronization be done through
the G status, since that's how stack scans are otherwise synchronized,
but adding a new lock is a much smaller change and G statuses are full
of subtlety.

Fixes #11863.

Change-Id: Ie89614a6238bb9c6a5b1190499b0b48ec759eaf7
Reviewed-on: https://go-review.googlesource.com/12748
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-29 19:31:46 +00:00
Rick Hudson
e95bc5fef7 runtime: force mutator to give work buffer to GC
The scheduler, work buffer's dispose, and write barriers
can conspire to hide the a pointer from the GC's concurent
mark phase. If this pointer is the only path to a large
amount of marking the STW mark termination phase may take
a lot of time.

Consider the following:
1) dispose places a work buffer on the partial queue
2) the GC is busy so it does not immediately remove and
   process the work buffer
3) the scheduler runs a mutator whose write barrier dequeues the
   work buffer from the partial queue so the GC won't see it
This repeats until the GC reaches the mark termination
phase where the GC finally discovers the pointer along
with a lot of work to do.

This CL fixes the problem by having the mutator
dispose of the buffer to the full queue instead of
the partial queue. Since the write buffer never asks for full
buffers the conspiracy described above is not possible.

Updates #11694.

Change-Id: I2ce832f9657a7570f800e8ce4459cd9e304ef43b
Reviewed-on: https://go-review.googlesource.com/12840
Reviewed-by: Austin Clements <austin@google.com>
2015-07-29 18:56:11 +00:00
Rob Pike
ff991940f1 doc: add json tokenizer to go1.5.html
Change-Id: I45d92fed757fa1866d5b80e53ed1af6712fa6741
Reviewed-on: https://go-review.googlesource.com/12782
Reviewed-by: Russ Cox <rsc@golang.org>
2015-07-29 06:10:27 +00:00
Mikio Hara
861af80458 cmd/internal/asm: delete
Updates #10510.

Change-Id: Ib4d39943969d18517b373292b83d87650d5df12a
Reviewed-on: https://go-review.googlesource.com/12787
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-07-29 04:53:08 +00:00
Rob Pike
ba0c142d32 cmd: delete old[5689]a
These are the old assemblers written in C, and now they are
not needed.

Fixes #10510.

Change-Id: Id9337ffc8eccfd93c84b2e23f427fb1a576b543d
Reviewed-on: https://go-review.googlesource.com/12784
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2015-07-29 03:45:26 +00:00