It turns out that there is a path that initializes netpoll and opens
file descriptors before running the os/exec init function: on some
systems, the uses of NewFile when setting os.Stdin and friends can
initialize netpoll which can open file descriptors. This in itself
is not a problem, but when we check whether the new files are open
using os.NewFile, a side-effect is to put them into non-blocking mode.
This can then break future uses of netpoll.

Updates #35469
Fixes #35566

Change-Id: I1b2e2c943695d1c2d29496b050abbce9ee710a00
Reviewed-on: https://go-review.googlesource.com/c/go/+/207078Reviewed-by: Bryan C. Mills <bcmills@google.com>

The bash version of the test wrote intermediate files to its testdata directory.

Updates #28387
Updates #30316
Fixes #35536

Change-Id: Ib81b547d3c43e90df713a2172c8f399fefb53c68
Reviewed-on: https://go-review.googlesource.com/c/go/+/206901
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The bounds in the last carry branch were wrong as there
is no reason for len(u) >= n+n/2 to always hold true.

We also adjust test to avoid using a remainder of 1
(in which case, the last step of the algorithm computes
(qhatv+1) - qhatv which rarely produces a carry).

Change-Id: I69fbab9c5e19d0db1c087fbfcd5b89352c2d26fb
Reviewed-on: https://go-review.googlesource.com/c/go/+/206839
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>

In the discussion of CL 171828 we decided that it was not necessary to
acquire timersLock around the call to moveTimers, because the world is
stopped. However, that is not correct, as sysmon runs even when the world
is stopped, and it calls timeSleepUntil which looks through the timers.
timeSleepUntil acquires timersLock, but that doesn't help if moveTimers
is running at the same time.

Updates #6239
Updates #27707
Updates #35462

Change-Id: I346c5bde594c4aff9955ae430b37c2b6fc71567f
Reviewed-on: https://go-review.googlesource.com/c/go/+/206938
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>

Change-Id: I09090effcc5d814d4e024da3f944e825365588f1
Reviewed-on: https://go-review.googlesource.com/c/go/+/205477
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Test fix: in dwarf_test.go don't try to run the TestDWARF testpoint on
windows with c-archive build mode (linker + debug/pe support for that
build mode on Windows is not fully baked it seems).

Fixes #35512.

Change-Id: I1c87ff3d62e5b98e75062b184d762fb5ed937745
Reviewed-on: https://go-review.googlesource.com/c/go/+/206899
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>

Our attempts to close existing open files are flaky. They will fail if,
for example, file descriptor 3 is open when the test binary starts.
Instead, report any such cases, and skip TestExtraFiles.

Updates #35469

Change-Id: I7caec083f3f4a31579bf28fc9c82ae89b1bde49a
Reviewed-on: https://go-review.googlesource.com/c/go/+/206939Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>

change "fp" to "fd".

Change-Id: I00e5fafcb68891356d508c49aa89969bfed7ed10
GitHub-Last-Rev: b06f976a3bacc6fc6f1fd0e4fc8c50da9764f736
GitHub-Pull-Request: golang/go#35557
Reviewed-on: https://go-review.googlesource.com/c/go/+/207038Reviewed-by: Keith Randall <khr@golang.org>

In CL 206757 I added a log.Printf to identify when GOROOT is not read-only.
However, it interacts badly with test sharding in the builders:
the log is repeated for every shard.

Since the log statement isn't particularly high-value, just remove it.

Updates #30316

Change-Id: I385a7f35da59e38ad8b9beef92dc11af931d9571
Reviewed-on: https://go-review.googlesource.com/c/go/+/206898
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Carlos Amedee <carlos@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Not a fix, but will give us more info when it flakes again.

Updates #35113

Change-Id: I2f90c24530c1bea81dd9d8c7a59f4b0640dfa4c2
Reviewed-on: https://go-review.googlesource.com/c/go/+/206819
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>

Provide initial linker support for riscv64.

Based on riscv-go port.

Updates #27532

Change-Id: I8a881ce41cd49efef0358bad9171d4d18aaf7ab2
Reviewed-on: https://go-review.googlesource.com/c/go/+/204624
Run-TryBot: Joel Sing <joel@sing.id.au>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Change-Id: Icd5006e37861d892a5f3d4397c3826179c1b12ad
Reviewed-on: https://go-review.googlesource.com/c/go/+/206657
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Katie Hockman <katie@golang.org>

The problem should be fixed by the previous CL. Reenable async
preemption on darwin/arm64.

Updates #35439.

Change-Id: I93e8c4702b4d8fe6abaa6fc9c27def5c8aed1b59
Reviewed-on: https://go-review.googlesource.com/c/go/+/206419Reviewed-by: Keith Randall <khr@golang.org>

iOS does not support SA_ONSTACK. The signal handler runs on the
G stack. Any writes below the SP may be clobbered by the signal
handler (even without call injection). So we save LR after
decrementing SP on iOS.

Updates #35439.

Change-Id: Ia6d7a0669e0bcf417b44c031d2e26675c1184165
Reviewed-on: https://go-review.googlesource.com/c/go/+/206418
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

Change-Id: I9596536e04aef034623b51b42f44e4978f07ac47
Reviewed-on: https://go-review.googlesource.com/c/go/+/204339
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

Some, but not all, architectures mix in OS-provided random seeds when
initializing the fastrand state. The others have TODOs saying we need
to do the same. Lift that logic up in the architecture-independent
part, and use memhash to mix the seed instead of a simple addition.

Previously, dumping the fastrand state at initialization would yield
something like the following on linux-amd64, where the values in the
first column do not change between runs (as thread IDs are sequential
and always start at 0), and the values in the second column, while
changing every run, are pretty correlated:

first run:

0x0 0x44d82f1c
0x5f356495 0x44f339de
0xbe6ac92a 0x44f91cd8
0x1da02dbf 0x44fd91bc
0x7cd59254 0x44fee8a4
0xdc0af6e9 0x4547a1e0
0x3b405b7e 0x474c76fc
0x9a75c013 0x475309dc
0xf9ab24a8 0x4bffd075

second run:

0x0 0xa63fc3eb
0x5f356495 0xa6648dc2
0xbe6ac92a 0xa66c1c59
0x1da02dbf 0xa671bce8
0x7cd59254 0xa70e8287
0xdc0af6e9 0xa7129d2e
0x3b405b7e 0xa7379e2d
0x9a75c013 0xa7e4c64c
0xf9ab24a8 0xa7ecce07

With this change, we get initial states that appear to be much more
unpredictable, both within the same run as well as between runs:

0x11bddad7 0x97241c63
0x553dacc6 0x2bcd8523
0x62c01085 0x16413d92
0x6f40e9e6 0x7a138de6
0xa4898053 0x70d816f0
0x5ca5b433 0x188a395b
0x62778ca9 0xd462c3b5
0xd6e160e4 0xac9b4bd
0xb9571d65 0x597a981d

Change-Id: Ib22c530157d74200df0083f830e0408fd4aaea58
Reviewed-on: https://go-review.googlesource.com/c/go/+/203439
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

https://github.com/google/pprof/compare/54271f7e092f...27840fff0d09

Change-Id: I7ded9be6deaaf8d11bd8d228bca8d7eb3ada8774
Reviewed-on: https://go-review.googlesource.com/c/go/+/205780
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Updates #35518.

Change-Id: Icd052c8c68aae32696b5831a29e04cc4cb224b06
Reviewed-on: https://go-review.googlesource.com/c/go/+/206820
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This test was failing when GOROOT was read-only.

(I'm not sure why that was the case, but it's simpler to convert to to
a script than to try to debug the non-script test.)

Updates #28387

Change-Id: I9943e28d990e5d8b01da10e70531f3ab99e319a7
Reviewed-on: https://go-review.googlesource.com/c/go/+/206897
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Change-Id: I72de8cb5e1df7a73e46a4b7e5b4e7290fcca4bc1
Reviewed-on: https://go-review.googlesource.com/c/go/+/204162
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

EpollEvent needs padding before Fd as was already done for x/sys/unix in
CL 21971.

Fixes #35479

Change-Id: Iee963f9e26d0a23d16d6bab736fd71ae7f502894
Reviewed-on: https://go-review.googlesource.com/c/go/+/206838
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

There is a (theoretical, but possible) chance that the
random number values a, b used for TestDiv are 0 or 1,
in which case the test would fail.

This CL makes sure that a >= 1 and b >= 2 at all times.

Fixes #35523.

Change-Id: I6451feb94241249516a821cd0066e95a0c65b0ed
Reviewed-on: https://go-review.googlesource.com/c/go/+/206818
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #29583

Change-Id: Ia89433bddd4c9f67ec1f0150b730cde8a7e973ee
Reviewed-on: https://go-review.googlesource.com/c/go/+/206759
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

This CL detects infinite loops due to negative dereference cycles
during escape analysis, and terminates the loop gracefully. We still
fail to print a complete explanation of the escape path, but esc.go
didn't print *any* explanation for these test cases, so the release
blocking issue here is simply that we don't infinite loop.

Updates #35518.

Change-Id: I39beed036e5a685706248852f1fa619af3b7abbc
Reviewed-on: https://go-review.googlesource.com/c/go/+/206619
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Also log a message and skip the Chmods if running as root.

Updates #30316

Change-Id: Ifb68d06ce845275a72d64c808407e8609df270bc
Reviewed-on: https://go-review.googlesource.com/c/go/+/206757
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

At least on Darwin notewakeup is not async-signal-safe.

Fixes #35276

Change-Id: I1d7523715e8e77dbd7f21d9b1ed131e52d46cc41
Reviewed-on: https://go-review.googlesource.com/c/go/+/206078Reviewed-by: Austin Clements <austin@google.com>

If no writes to the package buffer happen, then the package clause
does not get printed. This is a bug for cases where a file just contains
the package clause.

We fix this by separating the printing of package clause to a new
function and calling it from (*pkgBuffer).Write as well as (*Package).flush.

Updates #31457

Change-Id: Ia3bd0ea3963274c460a45d1e37fafc6ee0a197f0
Reviewed-on: https://go-review.googlesource.com/c/go/+/206128
Run-TryBot: Agniva De Sarker <agniva.quicksilver@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

The current division algorithm produces one word of result at a time,
using 2-word division to compute the top word and mulAddVWW to compute
the remainder. The top word may need to be adjusted by 1 or 2 units.

The recursive version, based on Burnikel, Ziegler, "Fast Recursive Division",
uses the same principles, but in a multi-word setting, so that
multiplication benefits from the Karatsuba algorithm (and possibly later
improvements).

benchmark                             old ns/op        new ns/op      delta
BenchmarkDiv/20/10-4                  38.2             38.3           +0.26%
BenchmarkDiv/40/20-4                  38.7             38.5           -0.52%
BenchmarkDiv/100/50-4                 62.5             62.6           +0.16%
BenchmarkDiv/200/100-4                238              259            +8.82%
BenchmarkDiv/400/200-4                311              338            +8.68%
BenchmarkDiv/1000/500-4               604              649            +7.45%
BenchmarkDiv/2000/1000-4              1214             1278           +5.27%
BenchmarkDiv/20000/10000-4            38279            36510          -4.62%
BenchmarkDiv/200000/100000-4          3022057          1359615        -55.01%
BenchmarkDiv/2000000/1000000-4        310827664        54012939       -82.62%
BenchmarkDiv/20000000/10000000-4      33272829421      1965401359     -94.09%
BenchmarkString/10/Base10-4           158              156            -1.27%
BenchmarkString/100/Base10-4          797              792            -0.63%
BenchmarkString/1000/Base10-4         3677             3814           +3.73%
BenchmarkString/10000/Base10-4        16633            17116          +2.90%
BenchmarkString/100000/Base10-4       5779029          1793808        -68.96%
BenchmarkString/1000000/Base10-4      889840820        85524031       -90.39%
BenchmarkString/10000000/Base10-4     134338236860     4935657026     -96.33%

Fixes #21960
Updates #30943

Change-Id: I134c6f81a47870c688ca95b6081eb9211def15a2
Reviewed-on: https://go-review.googlesource.com/c/go/+/172018Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

An error check was missing: If the first argument of a pipeline is
parenthesized, and the pipeline has further arguments, then
syntactically the pipeline is a function invocation and there must
be a "call". Tricky rare corner case, but easily caught.

Add the error check and some tests to verify behavior.

Fixes #31810.

Change-Id: Ica80b7c11284e4ea9e8cc94a01dbbc9a67e42079
Reviewed-on: https://go-review.googlesource.com/c/go/+/206124Reviewed-by: Ian Lance Taylor <iant@golang.org>

Fixes #30955

Change-Id: I8a2bff5215ddf6c3a80b1e760cb72b0bb9a5e0d3
Reviewed-on: https://go-review.googlesource.com/c/go/+/206122Reviewed-by: Robert Griesemer <gri@golang.org>

We use the typedValue map to prevent showing typed variables
and constants from appearing in the VARIABLES/CONSTANTS section
because they will be anyways shown in the TYPES section
for that type.

However, when a type is unexported, but the variable is exported,
then unconditionally setting it to true in the map suppresses it
from being shown in the VARIABLES section. Thus, we set the
variable or constant in the typedValue map only when
the type name is exported.

Fixes #31067

Change-Id: Id3ec4b313c9ea7e3ce6fe279680d56f65451719f
Reviewed-on: https://go-review.googlesource.com/c/go/+/206129
Run-TryBot: Agniva De Sarker <agniva.quicksilver@gmail.com>
Reviewed-by: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

Fixes #29793

Change-Id: I6e389d166c2d9a2ba8664a41f4b9569f2481b27f
Reviewed-on: https://go-review.googlesource.com/c/go/+/205177
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Katie Hockman <katie@golang.org>

Fixes #30325

Change-Id: I497110224bb73ecfcc4655698a794e7aa4a66925
Reviewed-on: https://go-review.googlesource.com/c/go/+/175517
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>

The cipher suites were apparently renamed late in the standardization
process, and we picked up the legacy name. We can't remove the old
constants, but add correctly named ones.

Fixes #32061

Change-Id: I65ee25c12c10934391af88b76b18565da67453fa
Reviewed-on: https://go-review.googlesource.com/c/go/+/205068
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>

TLS 1.3, which requires RSA-PSS, is now enabled without a GODEBUG
opt-out, and with the introduction of
Certificate.SupportedSignatureAlgorithms (#28660) there is a
programmatic way to avoid RSA-PSS (disable TLS 1.3 with MaxVersion and
use that field to specify only PKCS#1 v1.5 SignatureSchemes).

This effectively reverts 0b3a57b5,
although following CL 205061 all of the signing-side logic is
conveniently centralized in signatureSchemesForCertificate.

Fixes #32425

Change-Id: I7c9a8893bb5d518d86eae7db82612b9b2cd257d7
Reviewed-on: https://go-review.googlesource.com/c/go/+/205063
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Katie Hockman <katie@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>

This will let applications stop crypto/tls from using a certificate key
with an algorithm that is not supported by its crypto.Signer, like
hardware backed keys that can't do RSA-PSS.

Fixes #28660

Change-Id: I294cc06bddf813fff35c5107540c4a1788e1dace
Reviewed-on: https://go-review.googlesource.com/c/go/+/205062
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>

Now that we have a full implementation of the logic to check certificate
compatibility, we can let applications just list multiple chains in
Certificates (for example, an RSA and an ECDSA one) and choose the most
appropriate automatically.

NameToCertificate only maps each name to one chain, so simply deprecate
it, and while at it simplify its implementation by not stripping
trailing dots from the SNI (which is specified not to have any, see RFC
6066, Section 3) and by not supporting multi-level wildcards, which are
not a thing in the WebPKI (and in crypto/x509).

The performance of SupportsCertificate without Leaf is poor, but doesn't
affect current users. For now document that, and address it properly in
the next cycle. See #35504.

While cleaning up the Certificates/GetCertificate/GetConfigForClient
behavior, also support leaving Certificates/GetCertificate nil if
GetConfigForClient is set, and send unrecognized_name when there are no
available certificates.

Fixes #29139
Fixes #18377

Change-Id: I26604db48806fe4d608388e55da52f34b7ca4566
Reviewed-on: https://go-review.googlesource.com/c/go/+/205059
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Katie Hockman <katie@golang.org>

Also, add Version to CertificateRequestInfo, as the semantics of
SignatureSchemes change based on version: the ECDSA SignatureSchemes are
only constrained to a specific curve in TLS 1.3.

Fixes #32426

Change-Id: I7a551bea864799e98118349ac2476162893d1ffd
Reviewed-on: https://go-review.googlesource.com/c/go/+/205058
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>

We'll also use this function for a better selection logic from
Config.Certificates in a later CL.

Updates #32426

Change-Id: Ie239574d02eb7fd2cf025ec36721c8c7e082d0bc
Reviewed-on: https://go-review.googlesource.com/c/go/+/205057Reviewed-by: Katie Hockman <katie@golang.org>

This refactors a lot of the certificate support logic to make it cleaner
and reusable where possible. These changes will make the following CLs
much simpler.

In particular, the heavily overloaded pickSignatureAlgorithm is gone.
That function used to cover both signing and verifying side, would work
both for pre-signature_algorithms TLS 1.0/1.1 and TLS 1.2, and returned
sigalg, type and hash.

Now, TLS 1.0/1.1 and 1.2 are differentiated at the caller, as they have
effectively completely different logic. TLS 1.0/1.1 simply use
legacyTypeAndHashFromPublicKey as they employ a fixed hash function and
signature algorithm for each public key type. TLS 1.2 is instead routed
through selectSignatureScheme (on the signing side) or
isSupportedSignatureAlgorithm (on the verifying side) and
typeAndHashFromSignatureScheme, like TLS 1.3.

On the signing side, signatureSchemesForCertificate was already version
aware (for PKCS#1 v1.5 vs PSS support), so selectSignatureScheme just
had to learn the Section 7.4.1.4.1 defaults for a missing
signature_algorithms to replace pickSignatureAlgorithm.

On the verifying side, pickSignatureAlgorithm was also checking the
public key type, while isSupportedSignatureAlgorithm +
typeAndHashFromSignatureScheme are not, but that check was redundant
with the one in verifyHandshakeSignature.

There should be no major change in behavior so far. A few minor changes
came from the refactor: we now correctly require signature_algorithms in
TLS 1.3 when using a certificate; we won't use Ed25519 in TLS 1.2 if the
client didn't send signature_algorithms; and we don't send
ec_points_format in the ServerHello (a compatibility measure) if we are
not doing ECDHE anyway because there are no mutually supported curves.

The tests also got simpler because they test simpler functions. The
caller logic switching between TLS 1.0/1.1 and 1.2 is tested by the
transcript tests.

Updates #32426

Change-Id: Ice9dcaea78d204718f661f8d60efdb408ba41577
Reviewed-on: https://go-review.googlesource.com/c/go/+/205061Reviewed-by: Katie Hockman <katie@golang.org>