The spans array is allocated in runtime·mallocinit.  On a
32-bit system the number of entries in the spans array is
MaxArena32 / PageSize, which (2U << 30) / (1 << 12) == (1 << 19).
So we are allocating an array that can hold 19 bits for an
index that can hold 20 bits.  According to the comment in the
function, this is intentional: we only allocate enough spans
(and bitmaps) for a 2G arena, because allocating more would
probably be wasteful.

But since the span index is simply the upper 20 bits of the
memory address, this scheme only works if memory addresses are
limited to the low 2G of memory.  That would be OK if we were
careful to enforce it, but we're not.  What we are careful to
enforce, in functions like runtime·MHeap_SysAlloc, is that we
always return addresses between the heap's arena_start and
arena_start + MaxArena32.

We generally get away with it because we start allocating just
after the program end, so we only run into trouble with
programs that allocate a lot of memory, enough to get past
address 0x80000000.

This changes the code that computes a span index to subtract
arena_start on 32-bit systems just as we currently do on
64-bit systems.

R=golang-codereviews, rsc
CC=golang-codereviews
https://golang.org/cl/49460043

It's difficult to make this much better w/o much
more effort. This is a rare case and probably not
worth it.

Fixes #6052.

R=golang-codereviews, bradfitz, adonovan
CC=golang-codereviews
https://golang.org/cl/49740045

R=golang-codereviews, minux.ma
CC=golang-codereviews
https://golang.org/cl/50190043

Fixes #6998.

R=golang-codereviews, gobot, r
CC=golang-codereviews
https://golang.org/cl/44880044

The renegotiation extension was introduced[1] due to an attack by Ray in
which a client's handshake was spliced into a connection that was
renegotiating, thus giving an attacker the ability to inject an
arbitary prefix into the connection.

Go has never supported renegotiation as a server and so this attack
doesn't apply. As a client, it's possible that at some point in the
future the population of servers will be sufficiently updated that
it'll be possible to reject connections where the server hasn't
demonstrated that it has been updated to address this problem.

We're not at that point yet, but it's good for Go servers to support
the extension so that it might be possible to do in the future.

[1] https://tools.ietf.org/search/rfc5746

R=golang-codereviews, mikioh.mikioh
CC=golang-codereviews
https://golang.org/cl/48580043

Generated by addca.

R=gobot
CC=golang-codereviews
https://golang.org/cl/49950043

NPTL uses SIGRTMIN (signal 32) to effect thread cancellation.
Go's runtime replaces NPTL's signal handler with its own, and
ends up aborting if a C library that ends up calling
pthread_cancel is used.

This patch prevents runtime from replacing NPTL's handler.

Fixes #6997.

R=golang-codereviews, iant, dvyukov
CC=golang-codereviews
https://golang.org/cl/47540043

Generated by addca.

R=gobot
CC=golang-codereviews
https://golang.org/cl/49940043

R=golang-codereviews, dave, minux.ma, gobot, jsing
CC=golang-codereviews
https://golang.org/cl/36020043

This prevents callers from using reflect to create a new
instance of errorCString with an arbitrary value and calling
the Error method to examine arbitrary memory.

Fixes #7084.

R=golang-codereviews, minux.ma, bradfitz
CC=golang-codereviews
https://golang.org/cl/49600043

R=iant
CC=golang-codereviews
https://golang.org/cl/48890044

Everything was doing this already with #defines.
Do it right.

R=golang-codereviews, jsing, 0intro, iant
CC=golang-codereviews
https://golang.org/cl/49090043

When printing the size, we often want to sort on that key.
Because it's used when looking for large things, make the
sort go from largest to smallest.

Perfect recreation of CL 45150044, which was lost to some blunder.

R=golang-codereviews, gobot, rsc
CC=golang-codereviews
https://golang.org/cl/48500044

    The CL 49090043 renamed Ureg structures to Ureg386,
    UregArm and UregAmd64. This broke build on Plan 9,
    since ureg_x86.h includes /386/include/ureg.h, which
    declares a structure named Ureg instead of Ureg386.

R=golang-codereviews, bradfitz
CC=golang-codereviews, rsc
https://golang.org/cl/49260043

R=dvyukov
CC=golang-codereviews
https://golang.org/cl/48840043

This lets stack splits work correctly when running under gdb
when gdb has inserted a breakpoint somewhere on the call
stack.

Fixes #6834.

R=golang-codereviews, minux.ma
CC=golang-codereviews
https://golang.org/cl/48650043

       writing /net/dns or /net/cs (see nbd(8)).

R=golang-codereviews
CC=0intro, golang-codereviews, rsc
https://golang.org/cl/49060043

Update #7069

R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/49180043

R=golang-codereviews, minux.ma, gobot, rsc, dave
CC=golang-codereviews
https://golang.org/cl/36040043

When recompiling a package whose basename is the name of a standard
package for testing with gccgo, a .o file with the basename of the
package being tested was being placed in the _test/ directory where the
compilation of the test binary then found it when looking for the
standard library package.

This change puts the object files in a separate directory.

Fixes #6793

R=golang-codereviews, dave, gobot, rsc, iant
CC=golang-codereviews
https://golang.org/cl/27650045

record finalizers and heap profile info.  Enables
removing the special bit from the heap bitmap.  Also
provides a generic mechanism for annotating occasional
heap objects.

finalizers
        overhead      per obj
old	680 B	      80 B avg
new	16 B/span     48 B

profile
        overhead      per obj
old	32KB	      24 B + hash tables
new	16 B/span     24 B

R=cshapiro, khr, dvyukov, gobot
CC=golang-codereviews
https://golang.org/cl/13314053

A server Handler (e.g. a proxy) can receive a Request, and
then turn around and give a copy of that Request.Body out to
the Transport. So then two goroutines own that Request.Body
(the server and the http client), and both think they can
close it on failure.  Therefore, all incoming server requests
bodies (always *http.body from transfer.go) need to be
thread-safe.

Fixes #6995

R=golang-codereviews, r
CC=golang-codereviews
https://golang.org/cl/46570043

R=golang-codereviews, r
CC=golang-codereviews
https://golang.org/cl/46310043

R=rsc
CC=golang-codereviews
https://golang.org/cl/48420044

Unbreak the build - we do not have a sha512 block implementation in
386 assembly (yet).

R=golang-codereviews, dave
CC=golang-codereviews
https://golang.org/cl/48520043

Fixes #6723.

R=rsc
CC=golang-codereviews
https://golang.org/cl/41570047

Benchmark on Intel(R) Xeon(R) CPU X5650  @ 2.67GHz

benchmark              old ns/op    new ns/op    delta
BenchmarkHash8Bytes         1779         1114  -37.38%
BenchmarkHash1K             9848         4894  -50.30%
BenchmarkHash8K            68513        32187  -53.02%

benchmark               old MB/s     new MB/s  speedup
BenchmarkHash8Bytes         4.50         7.18    1.60x
BenchmarkHash1K           103.97       209.19    2.01x
BenchmarkHash8K           119.57       254.51    2.13x

R=agl
CC=golang-codereviews
https://golang.org/cl/37150044

This change adds solaris to the list of supported operating
systems and allows cmd/dist to be built on Solaris.

This CL has to come first because we want the tools to ignore
solaris-specific files until the whole port is integrated.

R=golang-codereviews, jsing, rsc, minux.ma
CC=golang-codereviews
https://golang.org/cl/35900045

Include the <sys/mman.h> header for NetBSD mkerrors.sh. This brings
in constants used with mmap(2), msync(2) and mlockall(2).

The regeneration of the NetBSD zerror* files also picks clone(2)
related constants.

Update #4929.

R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/45510044

[]byte("string") was simplifying to
[]byte{0: 0x73, 1: 0x74, 2: 0x72, 3: 0x69, 4: 0x6e, 5: 0x67},
but that latter form takes up much more memory in the compiler.
Preserve the string form and recognize it to turn global variables
initialized this way into linker-initialized data.

Reduces the compiler memory footprint for a large []byte initialized
this way from approximately 10 kB/B to under 100 B/B.

See also issue 6643.

R=golang-codereviews, r, iant, oleku.konko, dave, gobot, bradfitz
CC=golang-codereviews
https://golang.org/cl/15930045

Usually when a message is signed it's first hashed because RSA has low
limits on the size of messages that it can sign. However, some
protocols sign short messages directly. This isn't a great idea because
the messages that can be signed suddenly depend on the size of the RSA
key, but several people on golang-nuts have requested support for
this and it's very easy to do.

R=golang-codereviews, rsc
CC=golang-codereviews
https://golang.org/cl/44400043

See https://golang.org/cl/44150043/

««« original CL description
regexp: use sync.Pool

For machines, not threads.

Update #4720

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/44150043
»»»

TBR=golang-dev
CC=golang-codereviews
https://golang.org/cl/48190043

ZIP64 Extra records are variably sized, but we weren't capping
our reading of the extra fields at its previously-declared
size.

No test because I don't know how to easily create such files
and don't feel like manually construction one.  But all
existing tests pass, and this is "obviously correct" (queue
laughter).

Fixes #7069

R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/48150043

Adds tests for branches handling call ordering which
were shown to be untested by the cover tool.

This is part of the refactoring of form parsing discussed
in CL 44040043. These tests may need to be changed later but
should help lock in the current behaviour.

R=golang-codereviews, dave, bradfitz
CC=golang-codereviews
https://golang.org/cl/46750043

R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/47570043

R=golang-codereviews, gobot, r, bradfitz
CC=golang-codereviews
https://golang.org/cl/37660044

Benchmark on Intel(R) Core(TM) i5-2500S CPU @ 2.70GHz (albeit in a VM)

benchmark              old ns/op    new ns/op    delta
BenchmarkHash8Bytes         1606          699  -56.48%
BenchmarkHash1K            21920         7268  -66.84%
BenchmarkHash8K           165696        53756  -67.56%

benchmark               old MB/s     new MB/s  speedup
BenchmarkHash8Bytes         4.98        11.44    2.30x
BenchmarkHash1K            46.72       140.88    3.02x
BenchmarkHash8K            49.44       152.39    3.08x

R=agl, cldorian
CC=golang-codereviews
https://golang.org/cl/44800044

The Domain and Path field of a parsed cookie have been
the unprocessed wire data since Go 1.0; this seems to
be okay for most applications so let's keep it.

Returning the unprocessed wire data makes it easy to
handle nonstandard or even broken clients without
consulting Raw or Unparsed of a cookie.

The RFC 6265 parsing rules for domain and path are
currently buried in net/http/cookiejar but could be
exposed in net/http if necessary.

R=bradfitz, nigeltao
CC=golang-codereviews
https://golang.org/cl/48060043

Document what values a PublicSuffixList must accept as
a domain in a call to PublicSuffix.

R=bradfitz, nigeltao
CC=golang-codereviews
https://golang.org/cl/47560044

Fixes #7063.

R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/47950043