[release-branch.go1.5] runtime: adjust the ppc64x memmove and memclr to copy by word as much as it can

Issue #12552 can happen on ppc64 too, although much less frequently in my
testing. I'm fairly sure this fixes it (2 out of 200 runs of oracle.test failed
without this change and 0 of 200 failed with it). It's also a lot faster for
large moves/clears:

name           old speed      new speed       delta
Memmove1-6      157MB/s ± 9%    144MB/s ± 0%    -8.20%         (p=0.004 n=10+9)
Memmove2-6      281MB/s ± 1%    249MB/s ± 1%   -11.53%        (p=0.000 n=10+10)
Memmove3-6      376MB/s ± 1%    328MB/s ± 1%   -12.64%        (p=0.000 n=10+10)
Memmove4-6      475MB/s ± 4%    345MB/s ± 1%   -27.28%         (p=0.000 n=10+8)
Memmove5-6      540MB/s ± 1%    393MB/s ± 0%   -27.21%        (p=0.000 n=10+10)
Memmove6-6      609MB/s ± 0%    423MB/s ± 0%   -30.56%         (p=0.000 n=9+10)
Memmove7-6      659MB/s ± 0%    468MB/s ± 0%   -28.99%         (p=0.000 n=8+10)
Memmove8-6      705MB/s ± 0%   1295MB/s ± 1%   +83.73%          (p=0.000 n=9+9)
Memmove9-6      740MB/s ± 1%   1241MB/s ± 1%   +67.61%         (p=0.000 n=10+8)
Memmove10-6     780MB/s ± 0%   1162MB/s ± 1%   +48.95%         (p=0.000 n=10+9)
Memmove11-6     811MB/s ± 0%   1180MB/s ± 0%   +45.58%          (p=0.000 n=8+9)
Memmove12-6     820MB/s ± 1%   1073MB/s ± 1%   +30.83%         (p=0.000 n=10+9)
Memmove13-6     849MB/s ± 0%   1068MB/s ± 1%   +25.87%        (p=0.000 n=10+10)
Memmove14-6     877MB/s ± 0%    911MB/s ± 0%    +3.83%        (p=0.000 n=10+10)
Memmove15-6     893MB/s ± 0%    922MB/s ± 0%    +3.25%         (p=0.000 n=10+9)
Memmove16-6     897MB/s ± 1%   2418MB/s ± 1%  +169.67%         (p=0.000 n=10+9)
Memmove32-6     908MB/s ± 0%   3927MB/s ± 2%  +332.64%         (p=0.000 n=10+8)
Memmove64-6    1.11GB/s ± 0%   5.59GB/s ± 0%  +404.64%          (p=0.000 n=9+9)
Memmove128-6   1.25GB/s ± 0%   6.71GB/s ± 2%  +437.49%         (p=0.000 n=9+10)
Memmove256-6   1.33GB/s ± 0%   7.25GB/s ± 1%  +445.06%        (p=0.000 n=10+10)
Memmove512-6   1.38GB/s ± 0%   8.87GB/s ± 0%  +544.43%        (p=0.000 n=10+10)
Memmove1024-6  1.40GB/s ± 0%  10.00GB/s ± 0%  +613.80%        (p=0.000 n=10+10)
Memmove2048-6  1.41GB/s ± 0%  10.65GB/s ± 0%  +652.95%         (p=0.000 n=9+10)
Memmove4096-6  1.42GB/s ± 0%  11.01GB/s ± 0%  +675.37%         (p=0.000 n=8+10)
Memclr5-6       269MB/s ± 1%    264MB/s ± 0%    -1.80%        (p=0.000 n=10+10)
Memclr16-6      600MB/s ± 0%    887MB/s ± 1%   +47.83%        (p=0.000 n=10+10)
Memclr64-6     1.06GB/s ± 0%   2.91GB/s ± 1%  +174.58%         (p=0.000 n=8+10)
Memclr256-6    1.32GB/s ± 0%   6.58GB/s ± 0%  +399.86%         (p=0.000 n=9+10)
Memclr4096-6   1.42GB/s ± 0%  10.90GB/s ± 0%  +668.03%         (p=0.000 n=8+10)
Memclr65536-6  1.43GB/s ± 0%  11.37GB/s ± 0%  +697.83%          (p=0.000 n=9+8)
GoMemclr5-6     359MB/s ± 0%    360MB/s ± 0%    +0.46%        (p=0.000 n=10+10)
GoMemclr16-6    750MB/s ± 0%   1264MB/s ± 1%   +68.45%        (p=0.000 n=10+10)
GoMemclr64-6   1.17GB/s ± 0%   3.78GB/s ± 1%  +223.58%         (p=0.000 n=10+9)
GoMemclr256-6  1.35GB/s ± 0%   7.47GB/s ± 0%  +452.44%        (p=0.000 n=10+10)

Update #12552

Change-Id: I7192e9deb9684a843aed37f58a16a4e29970e893
Reviewed-on: https://go-review.googlesource.com/14840Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/16907Reviewed-by: Russ Cox <rsc@golang.org>

Commit c257dfb1 attempted to fix recursive allocation in gcAssistAlloc;
however, it only reduced it: setting gp.gcalloc to 0 isn't sufficient
to disable assists at the beginning of the GC cycle when gp.gcscanwork
is also small or zero.

Fix this recursion more completely by setting gcalloc to a sentinel
value that directly disables assists.

Fixes #12894 (again).

Change-Id: I9599566222d8f540d0b39806846bfc702e6666e5
Reviewed-on: https://go-review.googlesource.com/15891
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

If gcAssistAlloc is unable to steal or perform enough scan work, it
calls timeSleep, which allocates. If this allocation requires
obtaining a new span, it will in turn attempt to assist GC. Since
there's likely still no way to satisfy the assist, it will sleep
again, and so on, leading to potentially deep (not infinite, but also
not bounded) recursion.

Fix this by disallowing assists during the timeSleep.

This same problem was fixed on master by 65aa2da6. That commit built on
several other changes and hence can't be directly cherry-picked. This
commit implements the same idea.

Fixes #12894.

Change-Id: I152977eb1d0a3005c42ff3985d58778f054a86d4
Reviewed-on: https://go-review.googlesource.com/15720Reviewed-by: Rick Hudson <rlh@golang.org>

Change-Id: I8da1c7a86adf6672e5e5c44cbab422706833c1da
Reviewed-on: https://go-review.googlesource.com/15350Reviewed-by: Andrew Gerrand <adg@golang.org>
Reviewed-on: https://go-review.googlesource.com/15244

Change-Id: Ib1bfe4038e2b125a31acd9ff7772e462b0a6358f
Reviewed-on: https://go-review.googlesource.com/14852Reviewed-by: Andrew Gerrand <adg@golang.org>
Reviewed-on: https://go-review.googlesource.com/14854

Change-Id: I98d9fefd923e2a35031385045382ba372f1d614a
Reviewed-on: https://go-review.googlesource.com/14401Reviewed-by: Andrew Gerrand <adg@golang.org>

Change-Id: I56452559acc432e06c15844d3f25dbeacafe77b7
Reviewed-on: https://go-review.googlesource.com/14402Reviewed-by: Andrew Gerrand <adg@golang.org>
Reviewed-on: https://go-review.googlesource.com/14403

These instructions are special cases that were missed in the translation.
The second argument must go into the Reg field not the To field.

Fixes #12458

For Go 1.5.1

Change-Id: Iad57c60c7e38e3bcfafda483ed5037ce670e8816
Reviewed-on: https://go-review.googlesource.com/14183Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-on: https://go-review.googlesource.com/14358Reviewed-by: Chris Broadfoot <cbro@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

In short, %c should just give you the next rune, period.
Apparently this is the design. I use the term loosely.

Fixes #12275

Change-Id: I6f30bed442c0e88eac2244d465c7d151b29cf393
Reviewed-on: https://go-review.googlesource.com/13821Reviewed-by: Andrew Gerrand <adg@golang.org>
Reviewed-on: https://go-review.googlesource.com/14395

Fixes #12288.

For inclusion in the 1.5.1 release.

Change-Id: I9354b7eaa76000498465c4a5cbab7246de9ecb7c
Reviewed-on: https://go-review.googlesource.com/14382Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-on: https://go-review.googlesource.com/14394

Some commits made by Aram from his personal email address are
actually copyright Oracle:

a77fcb3f net: fix comment in sendFile
b0e71f46 net: link with networking libraries when net package is in use
92e959a4 syscall, net: use sendfile on Solaris
db8d5b76 net: try to fix setKeepAlivePeriod on Solaris
fe5ef5c9 runtime, syscall: link Solaris binaries directly instead of using dlopen/dlsym
2b90c3e8 go/build: enable cgo by default on solaris/amd64
2d18ab75 doc/progs: disable cgo tests that use C.Stdout on Solaris
2230e9d2 misc/cgo: add various solaris build lines
649c7b6d net: add cgo support for Solaris
24396dae os/user: small fixes for Solaris
121489cb runtime/cgo: add cgo support for solaris/amd64
83b25d93 cmd/ld: make .rela and .rela.plt sections contiguous
c94f1f79 runtime: always load address of libcFunc on Solaris
e481aac0 cmd/6l: use .plt instead of .got on Solaris

See bug for clarification.

Fixes #12452

Change-Id: I0aeb1b46c0c7d09c5c736e383ecf40240d2cf85f
Reviewed-on: https://go-review.googlesource.com/14380Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-on: https://go-review.googlesource.com/14393Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

This reverts commit f265044a.

Change-Id: I454f9da3a40d6724ab106aae904b8e77756aae99
Reviewed-on: https://go-review.googlesource.com/14383
Run-TryBot: Chris Broadfoot <cbro@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Currently the stack barrier stub blindly unwinds the next stack
barrier from the G's stack barrier array without checking that it's
the right stack barrier. If through some bug the stack barrier array
position gets out of sync with where we actually are on the stack,
this could return to the wrong PC, which would lead to difficult to
debug crashes. To address this, this commit adds a check to the amd64
stack barrier stub that it's unwinding the correct stack barrier.

Updates #12238.

Change-Id: If824d95191d07e2512dc5dba0d9978cfd9f54e02
Reviewed-on: https://go-review.googlesource.com/13948Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-on: https://go-review.googlesource.com/14241Reviewed-by: Austin Clements <austin@google.com>

Accepting a request with a nil body was never explicitly supported but
happened to work in the past.

This doesn't happen in most cases because usually people pass
a Server's incoming Request to the ReverseProxy's ServeHTTP method,
and incoming server requests are guaranteed to have non-nil bodies.

Still, it's a regression, so fix.

Fixes #12344

Change-Id: Id9a5a47aea3f2875d195b66c9a5f8581c4ca2aed
Reviewed-on: https://go-review.googlesource.com/13935Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-on: https://go-review.googlesource.com/14245

This worked in Go 1.4 but was lost in the "pure Go" lookup
routines substituted late in the Go 1.5 cycle.

Fixes #12263.

Change-Id: I77ec9d97cd8e67ace99d6ac965e5bc16c151ba83
Reviewed-on: https://go-review.googlesource.com/13915Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-on: https://go-review.googlesource.com/14243Reviewed-by: Ian Lance Taylor <iant@golang.org>

[release-branch.go1.5] cmd/go: properly ignore import comments for vendored packages rooted at GOPATH

Fixes #12232.

Change-Id: Ide3fb7f5fc5ae377ae8683fbb94fd0dc01480549
Reviewed-on: https://go-review.googlesource.com/13924Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-on: https://go-review.googlesource.com/14228Reviewed-by: Ian Lance Taylor <iant@golang.org>

The issue 12226 has been caused by the allocation of the same register
for the equality check of two byte values. The code in cgen.go freed the
register for the second operand before the allocation of the register
for the first operand.

Fixes #12226

Change-Id: Ie4dc33a488bd48a17f8ae9b497fd63c1ae390555
Reviewed-on: https://go-review.googlesource.com/13771Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-on: https://go-review.googlesource.com/14227Reviewed-by: Ian Lance Taylor <iant@golang.org>

Currently the runtime can install stack barriers in any frame.
However, the frame of cgocallback_gofunc is special: it's the one
function that switches from a regular G stack to the system stack on
return. Hence, the return PC slot in its frame on the G stack is
actually used to save getg().sched.pc (so tracebacks appear to unwind
to the last Go function running on that G), and not as an actual
return PC for cgocallback_gofunc.

Because of this, if we install a stack barrier in cgocallback_gofunc's
return PC slot, when cgocallback_gofunc does return, it will move the
stack barrier stub PC in to getg().sched.pc and switch back to the
system stack. The rest of the runtime doesn't know how to deal with a
stack barrier stub in sched.pc: nothing knows how to match it up with
the G's stack barrier array and, when the runtime removes stack
barriers, it doesn't know to undo the one in sched.pc. Hence, if the C
code later returns back in to Go code, it will attempt to return
through the stack barrier saved in sched.pc, which may no longer have
correct unwinding information.

Fix this by blacklisting cgocallback_gofunc's frame so the runtime
won't install a stack barrier in it's return PC slot.

Fixes #12238.

Change-Id: I46aa2155df2fd050dd50de3434b62987dc4947b8
Reviewed-on: https://go-review.googlesource.com/13944Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-on: https://go-review.googlesource.com/14229Reviewed-by: Austin Clements <austin@google.com>

Currently enabling the debugging mode where stack barriers are
installed at every frame requires recompiling the runtime. However,
this is potentially useful for field debugging and for runtime tests,
so make this mode a GODEBUG.

Updates #12238.

Change-Id: I6fb128f598b19568ae723a612e099c0ed96917f5
Reviewed-on: https://go-review.googlesource.com/13947Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-on: https://go-review.googlesource.com/14240Reviewed-by: Austin Clements <austin@google.com>

A comparison of the form l == r where l is an interface and r is
concrete performs a type assertion on l to convert it to r's type.
However, the compiler fails to zero the temporary where the result of
the type assertion is written, so if the type is a pointer type and a
stack scan occurs while in the type assertion, it may see an invalid
pointer on the stack.

Fix this by zeroing the temporary. This is equivalent to the fix for
type switches from c4092ac3.

Fixes #12253.

Change-Id: Iaf205d456b856c056b317b4e888ce892f0c555b9
Reviewed-on: https://go-review.googlesource.com/13872Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-on: https://go-review.googlesource.com/14242Reviewed-by: Austin Clements <austin@google.com>

Change-Id: I1b9f6ad322a7f68fa160c4f09d7fb56815e505a7
Reviewed-on: https://go-review.googlesource.com/13828Reviewed-by: Rob Pike <r@golang.org>
Reviewed-on: https://go-review.googlesource.com/14244Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

For ARM machines, the assembler supports list of registers
operands such as [R1,R2].

A list missing a ']' results in the parser issuing many errors
and consuming all the tokens. At EOF (i.e. end of the line),
it still loops.

Normally, a counter is maintained to make sure the parser
stops after 10 errors. However, multiple errors occuring on the
same line are simply ignored. Only the first one is reported.
At most one error per line is accounted.

Missing ']' in a register list therefore results in an
infinite loop.

Fixed the parser by explicitly checking for ']' to interrupt
this loops

In the operand tests, also fixed a wrong entry which I think was
not set on purpose (but still led to a successful result).

Fixes #11764

Change-Id: Ie87773388ee0d21b3a2a4cb941d4d911d0230ba4
Reviewed-on: https://go-review.googlesource.com/13920Reviewed-by: Rob Pike <r@golang.org>
Reviewed-on: https://go-review.googlesource.com/14225

This changed in https://golang.org/cl/10761.

Update #12203.

Change-Id: Ia37ebb7ecba689ad3cb2559213d675f21cf03a95
Reviewed-on: https://go-review.googlesource.com/13799Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-on: https://go-review.googlesource.com/14226Reviewed-by: Minux Ma <minux@golang.org>

Some symbols, for example, masks requires 16-byte alignment, and
they are placed in the text section. Before this change, the text
section is only aligned to 4-byte, and it's making masks unaligned.

Fixes #12415.

Change-Id: I7767778d1b4f7d3e74c2719a02848350782a4160
Reviewed-on: https://go-review.googlesource.com/14166
Run-TryBot: Minux Ma <minux@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
(cherry picked from commit 821e124c)
Reviewed-on: https://go-review.googlesource.com/14279

At the moment, bootstrap.bash assumes it is called from a git working
copy. Hence, it fails to complete when running in an unpacked official
source tarball where .git and .gitignore do not exist. This fix adds a
test for existence for .git and a -f switch for the removal of
.gitignore.

Fixes #12223

Change-Id: I7f305b83b38d5115504932bd38dadb7bdeb5d487
Reviewed-on: https://go-review.googlesource.com/13770Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Andrew Gerrand <adg@golang.org>
Reviewed-on: https://go-review.googlesource.com/14281

Fixes external linking of net/http tests (or anything that uses
sendfile).

Fixes #12390.

Change-Id: Iee08998cf66e7b0ce851db138a00ebae6dc2395e
Reviewed-on: https://go-review.googlesource.com/14072Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>
Reviewed-on: https://go-review.googlesource.com/14246
Run-TryBot: Chris Broadfoot <cbro@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>

Bring in the text from the proposal (with minor edits):
https://github.com/golang/proposal/blob/master/design/11502-securitypolicy.md

Fixes #11502

Change-Id: I92a987be66a0df60c1fad6c6c79f89bd8e9c12a8
Reviewed-on: https://go-review.googlesource.com/13955Reviewed-by: Jason Buberel <jbuberel@google.com>
Reviewed-on: https://go-review.googlesource.com/14224Reviewed-by: Andrew Gerrand <adg@golang.org>

Change-Id: I571965bc38a8b1060642a942b898797327f0c19c
Reviewed-on: https://go-review.googlesource.com/14195Reviewed-by: Andrew Gerrand <adg@golang.org>
Reviewed-on: https://go-review.googlesource.com/14199Reviewed-by: Chris Broadfoot <cbro@golang.org>

This updates the VERSION file.
The release proper has not happened yet.

Change-Id: I3e33b5f95aede0da8ca1aef0d9c381942873c9a8
Reviewed-on: https://go-review.googlesource.com/13702Reviewed-by: Rob Pike <r@golang.org>

Using merge instead of cherry-picks to simplify initial release.
Minor releases like Go 1.5.1 will have to use cherry-picks.

Fixes #12093.

Change-Id: If00393c58ace0da6f359b387cea9b779b123b920

This makes sure the release page in the release will mention the release.

Fixes #12102.

Change-Id: I36befd7dba7ba9e70ae3335e21c8841179ac4eff
Reviewed-on: https://go-review.googlesource.com/13490Reviewed-by: Rob Pike <r@golang.org>

This is especially important for LookupAddr, which used to be pure Go
(lightweight, one goroutine per call) and without this CL is now
unconditionally cgo (heavy, one thread per call).

Fixes #12190.

Change-Id: I43436a942bc1838b024225893e156f280a1e80cf
Reviewed-on: https://go-review.googlesource.com/13698Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Go 1.4 and before have always returned DNS names with a trailing dot
for reverse lookups, as they do for basically all other routines returning
DNS names. Go 1.4 and before always implemented LookupAddr using
pure Go (not C library calls).

Go 1.5 added the ability to make a C library call to implement LookupAddr.
Unfortunately the C library call returns a DNS name without a trailing dot
(an unrooted name), meaning that if turn off cgo during make.bash then
you still get the rooted name but with cgo on you get an unrooted name.
The unrooted name is inconsistent with the pure Go implementation
and with all previous Go releases, so change it to a rooted name.

Fixes #12189.

Change-Id: I3d6b72277c121fe085ea6af30e5fe8019fc490ad
Reviewed-on: https://go-review.googlesource.com/13697Reviewed-by: Rob Pike <r@golang.org>

Fixes #12191.

Change-Id: I5c7659ccb0566dad3613041d9e76be87ceacae61
Reviewed-on: https://go-review.googlesource.com/13700Reviewed-by: Rob Pike <r@golang.org>

Thanks to Nathan Youngman for spotting them.

Change-Id: I1856527af66a5d1965265ec3dcd639d3f6d74bcc
Reviewed-on: https://go-review.googlesource.com/13711Reviewed-by: Russ Cox <rsc@golang.org>

Saying "Power 64" was wrong for reasons I don't remember.
(Those reasons are why we stopped using GOARCH=power64.)

Change-Id: Ifaac78d5733bfc780df01b1a66da766af0b17726
Reviewed-on: https://go-review.googlesource.com/13675Reviewed-by: Rob Pike <r@golang.org>

Make clear that this list is the list of supported systems
for binary distributions, and that other systems may be
able to build the distribution from source, in addition
to using gccgo.

Drop freebsd/arm from the list on this page.
We have never issued a binary distribution for freebsd/arm,
and we're not going to start in Go 1.5, since we don't even
have a working builder for it.

Drop freebsd/386 from the list on the page,
because we are unable to build binary distributions, per adg.

I think the wording here should probably be revised further,
but not now.

Change-Id: Ib43b6b64f5c438bfb9aa4d3daa43393f1e33b71f
Reviewed-on: https://go-review.googlesource.com/13690Reviewed-by: Andrew Gerrand <adg@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

This was missed when we did the rename months ago
because cmd/vet did not live in the main tree.
Now vet's asmdecl checks will apply to ppc64 assembly too.

Change-Id: I687cba89fef702f29dd118de76a7ca1041c414f6
Reviewed-on: https://go-review.googlesource.com/13677Reviewed-by: Andrew Gerrand <adg@golang.org>

Change-Id: Iaeba7c55bbb9e11ac30f3b61369aa597acc30190
Reviewed-on: https://go-review.googlesource.com/13691Reviewed-by: Russ Cox <rsc@golang.org>

Update #11184 (linux/ppc64).
Filed #12178 (solaris) for Go 1.6.

Change-Id: I9e3a456aaccb49590ad4e14b53ddfefca5b0801c
Reviewed-on: https://go-review.googlesource.com/13679Reviewed-by: Russ Cox <rsc@golang.org>