Commit graph

73 commits

Author SHA1 Message Date
Michael Pratt
e252dcf9d3 runtime: always keep global reference to mp until mexit completes
Ms are allocated via standard heap allocation (`new(m)`), which means we
must keep them alive (i.e., reachable by the GC) until we are completely
done using them.

Ms are primarily reachable through runtime.allm. However, runtime.mexit
drops the M from allm fairly early, long before it is done using the M
structure. If that was the last reference to the M, it is now at risk of
being freed by the GC and used for some other allocation, leading to
memory corruption.

Ms with a Go-allocated stack coincidentally already keep a reference to
the M in sched.freem, so that the stack can be freed lazily. This
reference has the side effect of keeping this Ms reachable. However, Ms
with an OS stack skip this and are at risk of corruption.

Fix this lifetime by extending sched.freem use to all Ms, with the value
of mp.freeWait determining whether the stack needs to be freed or not.

Fixes #56243.

Change-Id: Ic0c01684775f5646970df507111c9abaac0ba52e
Reviewed-on: https://go-review.googlesource.com/c/go/+/443716
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Michael Pratt <mpratt@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
2022-10-18 20:57:24 +00:00
Michael Pratt
b486518964 runtime: tricky replacements of _g_ in os3_solaris.go
The argument to semacreate is always getg().m.

Change-Id: I4c4104cd6b57ab6b9ed0b7d11b8089bcc9fdd621
Reviewed-on: https://go-review.googlesource.com/c/go/+/418583
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-08-02 18:51:42 +00:00
Russ Cox
9839668b56 all: separate doc comment from //go: directives
A future change to gofmt will rewrite

	// Doc comment.
	//go:foo

to

	// Doc comment.
	//
	//go:foo

Apply that change preemptively to all comments (not necessarily just doc comments).

For #51082.

Change-Id: Iffe0285418d1e79d34526af3520b415a12203ca9
Reviewed-on: https://go-review.googlesource.com/c/go/+/384260
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-04-05 17:54:15 +00:00
Tobias Klauser
c3c74777bc runtime, syscall: implement syscall.Pipe using syscall.Pipe2 on solaris
All other platforms providing the pipe2 syscall already implement it
that way. Do so as well on solaris, which allows to drop
runtime.syscall_pipe and its dependencies as well.

Change-Id: Icf04777f21d1804da74325d173fefdc87caa42eb
Reviewed-on: https://go-review.googlesource.com/c/go/+/390716
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Trust: Matt Layher <mdlayher@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-03-08 21:16:53 +00:00
Tobias Klauser
9d34fc5108 runtime: remove fallback to pipe on platforms with pipe2
On Linux, the minimum required kernel version for Go 1.18 was be changed
to 2.6.32, see #45964. The pipe2 syscall was added in 2.6.27.

All other platforms already provide the pipe2 syscall in the minimum
supported version:
- DragonFly BSD added it in version 4.2, see
  https://www.dragonflybsd.org/release42/
- FreeBSD added it in version 10.0, see
  https://www.freebsd.org/cgi/man.cgi?pipe(2)#end
- NetBSD added it in version 6.0, see
  https://man.netbsd.org/pipe2.2#HISTORY
- OpenBSD added it in version 5.7, see
  https://man.openbsd.org/pipe.2#HISTORY
- Illumos supports it since 2013, see
  https://www.illumos.org/issues/3714
- Solaris supports it since 11.4

This also allows to remove setNonblock which was only used in the pipe
fallback path on these platforms.

Change-Id: I1f40d32fd3065d74e22af77b9ff2292b9cf66706
Reviewed-on: https://go-review.googlesource.com/c/go/+/389354
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-03-03 20:47:17 +00:00
Michael Pratt
0a5fae2a0e runtime, syscall: reimplement AllThreadsSyscall using only signals.
In issue 50113, we see that a thread blocked in a system call can result
in a hang of AllThreadsSyscall. To resolve this, we must send a signal
to these threads to knock them out of the system call long enough to run
the per-thread syscall.

Stepping back, if we need to send signals anyway, it should be possible
to implement this entire mechanism on top of signals. This CL does so,
vastly simplifying the mechanism, both as a direct result of
newly-unnecessary code as well as some ancillary simplifications to make
things simpler to follow.

Major changes:

* The rest of the mechanism is moved to os_linux.go, with fields in mOS
  instead of m itself.
* 'Fixup' fields and functions are renamed to 'perThreadSyscall' so they
  are more precise about their purpose.
* Rather than getting passed a closure, doAllThreadsSyscall takes the
  syscall number and arguments. This avoids a lot of hairy behavior:
    * The closure may potentially only be live in fields in the M,
      hidden from the GC. Not necessary with no closure.
    * The need to loan out the race context. A direct RawSyscall6 call
      does not require any race context.
    * The closure previously conditionally panicked in strange
      locations, like a signal handler. Now we simply throw.
* All manual fixup synchronization with mPark, sysmon, templateThread,
  sigqueue, etc is gone. The core approach is much simpler:
  doAllThreadsSyscall sends a signal to every thread in allm, which
  executes the system call from the signal handler. We use (SIGRTMIN +
  1), aka SIGSETXID, the same signal used by glibc for this purpose. As
  such, we are careful to only handle this signal on non-cgo binaries.

Synchronization with thread creation is a key part of this CL. The
comment near the top of doAllThreadsSyscall describes the required
synchronization semantics and how they are achieved.

Note that current use of allocmLock protects the state mutations of allm
that are also protected by sched.lock. allocmLock is used instead of
sched.lock simply to avoid holding sched.lock for so long.

Fixes #50113

Change-Id: Ic7ea856dc66cf711731540a54996e08fc986ce84
Reviewed-on: https://go-review.googlesource.com/c/go/+/383434
Reviewed-by: Austin Clements <austin@google.com>
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-02-15 15:40:35 +00:00
Michael Pratt
f8779b9e75 runtime: rename _m_ to mp [generated]
_g_, _p_, and _m_ are primarily vestiges of the C version of the
runtime, while today we prefer Go-style variable names (generally gp,
pp, and mp).

This change replaces all remaining uses of _m_ with mp. There are very
few remaining and all replacements are trivial.

[git-generate]
cd src/runtime

rf 'mv canpanic._m_ canpanic.mp'
GOOS=solaris \
  rf 'mv semasleep._m_ semasleep.mp'
GOOS=aix GOARCH=ppc64 \
  rf 'mv semasleep._m_ semasleep.mp'

Change-Id: I83690f7b4d4dc57557963100e9a2560ff343f3e8
Reviewed-on: https://go-review.googlesource.com/c/go/+/307813
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
2021-10-26 20:12:32 +00:00
Rhys Hiltner
f9e90f7e74 runtime: allow per-OS changes to unix profiler
Updates #35057

Change-Id: I56ea8f4750022847f0866c85e237a2cea40e0ff7
Reviewed-on: https://go-review.googlesource.com/c/go/+/342053
Run-TryBot: Rhys Hiltner <rhys@justin.tv>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Trust: Michael Knyszek <mknyszek@google.com>
2021-09-27 18:58:20 +00:00
Michael Anthony Knyszek
6d85891b29 [dev.typeparams] runtime: replace uses of runtime/internal/sys.PtrSize with internal/goarch.PtrSize [generated]
[git-generate]
cd src/runtime/internal/math
gofmt -w -r "sys.PtrSize -> goarch.PtrSize" .
goimports -w *.go
cd ../..
gofmt -w -r "sys.PtrSize -> goarch.PtrSize" .
goimports -w *.go

Change-Id: I43491cdd54d2e06d4d04152b3d213851b7d6d423
Reviewed-on: https://go-review.googlesource.com/c/go/+/328337
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2021-06-17 18:54:48 +00:00
Cherry Mui
626e89c261 [dev.typeparams] runtime: replace funcPC with internal/abi.FuncPCABIInternal
At this point all funcPC references are ABIInternal functions.
Replace with the intrinsics.

Change-Id: I3ba7e485c83017408749b53f92877d3727a75e27
Reviewed-on: https://go-review.googlesource.com/c/go/+/321954
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
2021-05-21 22:40:36 +00:00
Cherry Mui
a5cd89b8c3 [dev.typeparams] runtime: use internal/abi.FuncPCABI0 and cgo_unsafe_args for Solaris syscall wrappers
Similar to CL 313230, for Solaris (and Illumos). Also mark
functions that take address of one arg and pass to asmcgocall
cgo_unsafe_args, as it effectively takes address of all args.

Change-Id: I4281dd774719fb21ecba82e5ed94a609378a3df5
Reviewed-on: https://go-review.googlesource.com/c/go/+/321314
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
2021-05-20 16:07:12 +00:00
Ian Lance Taylor
862ddb37b4 runtime: rename walltime1 to walltime
Change-Id: Iec9de5ca56eb68d524bbaa0668515dbd09ad38a1
Reviewed-on: https://go-review.googlesource.com/c/go/+/314770
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
2021-04-29 14:15:04 +00:00
Russ Cox
0d94f989d1 runtime: clean up system calls during cgo callback init
During a cgocallback, the runtime calls needm to get an m.
The calls made during needm cannot themselves assume that
there is an m or a g (which is attached to the m).

In the old days of making direct system calls, the only thing
you had to do for such functions was mark them //go:nosplit,
to avoid the use of g in the stack split prologue.

But now, on operating systems that make system calls through
shared libraries and use code that saves state in the g or m
before doing so, it's not safe to assume g exists. In fact, it is
not even safe to call getg(), because it might fault deferencing
the TLS storage to find the g pointer (that storage may not be
initialized yet, at least on Windows, and perhaps on other systems
in the future).

The specific routines that are problematic are usleep and osyield,
which are called during lock contention in lockextra, called
from needm.

All this is rather subtle and hidden, so in addition to fixing the
problem on Windows, this CL makes the fact of not running on
a g much clearer by introducing variants usleep_no_g and
osyield_no_g whose names should make clear that there is no g.
And then we can remove the various sketchy getg() == nil checks
in the existing routines.

As part of this cleanup, this CL also deletes onosstack on Windows.
onosstack is from back when the runtime was implemented in C.
It predates systemstack but does essentially the same thing.
Instead of having two different copies of this code, we can use
systemstack consistently. This way we need not port onosstack
to each architecture.

This CL is part of a stack adding windows/arm64
support (#36439), intended to land in the Go 1.17 cycle.
This CL is, however, not windows/arm64-specific.
It is cleanup meant to make the port (and future ports) easier.

Change-Id: I3352de1fd0a3c26267c6e209063e6e86abd26187
Reviewed-on: https://go-review.googlesource.com/c/go/+/288793
Trust: Russ Cox <rsc@golang.org>
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
2021-02-19 00:01:25 +00:00
Jason A. Donenfeld
dbab079835 runtime: free Windows event handles after last lock is dropped
Calls to lock may need to use global members of mOS that also need to be
cleaned up before the thread exits. Before this commit, these resources
would leak. Moving them to be cleaned up in unminit, however, would race
with gstack on unix. So this creates a new helper, mdestroy, to release
resources that must be destroyed only after locks are no longer
required. We also move highResTimer lifetime to the same semantics,
since it doesn't help to constantly acquire and release the timer object
during dropm.

Updates #43720.

Change-Id: Ib3f598f3fda1b2bbcb608099616fa4f85bc1c289
Reviewed-on: https://go-review.googlesource.com/c/go/+/284137
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Trust: Alex Brainman <alex.brainman@gmail.com>
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
2021-01-18 18:16:12 +00:00
Ian Lance Taylor
904e1136c2 runtime: add pipe/pipe2 on Solaris
This adds pipe/pipe2 on Solaris as they exist on other Unix systems.
They were not added previously because Solaris does not need them
for netpollBreak. They are added now in preparation for using pipes
in TestSignalM.

Updates #35276

Change-Id: I53dfdf077430153155f0a79715af98b0972a841c
Reviewed-on: https://go-review.googlesource.com/c/go/+/206077
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-11-08 19:28:57 +00:00
Joshua M. Clulow
91f3997ec0 runtime: make NumCPU respect zone CPU cap on illumos
On illumos systems, check for the "zone.cpu-cap" resource control when
determining how many usable CPUs are available.  If the resource control
is not set, or we are unable to read it, ignore the failure and return
the value we used to return; i.e., the CPU count from
sysconf(_SC_NPROCESSORS_ONLN).

Fixes golang/go#35199

Change-Id: Ic8a408f84cd140d544d128f1281baad527fb5e35
Reviewed-on: https://go-review.googlesource.com/c/go/+/203758
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-10-28 18:06:12 +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
Ian Lance Taylor
b653c878b1 runtime: change read and write to return negative errno value
The internal read and write functions used to return -1 on error;
change them to return a negative errno value instead.
This will be used by later CLs in this series.

For most targets this is a simplification, although for ones that call
into libc it is a complication.

Updates #27707

Change-Id: Id02bf9487f03e7e88e4f2b85e899e986738697ad
Reviewed-on: https://go-review.googlesource.com/c/go/+/171823
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
2019-10-21 14:07:34 +00:00
Jerrin Shaji George
2df5cdbadf runtime: make nanotime use monotonic clock in Solaris
nanotime() currently uses the REALTIME clock to get the elapsed
time in Solaris. This commit changes it to use the MONOTONIC clock
instead, similar to how it's done in Linux and other OSs. Also changed
nanotime() and walltime() to call clock_gettime() library function
directly from Go code rather than from assembly.

Fixes #33674

Change-Id: Ie4a687b17d2140998ecd97af6ce048c86cf5fc02
Reviewed-on: https://go-review.googlesource.com/c/go/+/199502
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>
2019-10-11 20:01:28 +00:00
Austin Clements
4af3c17f8c runtime: wrap nanotime, walltime, and write
In preparation for general faketime support, this renames the existing
nanotime, walltime, and write functions to nanotime1, walltime1, and
write1 and wraps them with trivial Go functions. This will let us
inject different implementations on all platforms when faketime is
enabled.

Updates #30439.

Change-Id: Ice5ccc513a32a6d89ea051638676d3ee05b00418
Reviewed-on: https://go-review.googlesource.com/c/go/+/192738
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-09-04 17:56:09 +00:00
Russ Cox
60f67631a6 runtime: fix vet complaints for solaris/amd64, illumos/amd64
Working toward making the tree vet-safe instead of having
so many exceptions in cmd/vet/all/whitelist.

This CL makes "go vet -unsafeptr=false runtime" happy for these GOOS/GOARCHes,
while keeping "GO_BUILDER_NAME=misc-vetall go tool dist test" happy too.

For #31916.

Change-Id: Ic64f7f4034695dd4c32c9b7f258960faf3742a83
Reviewed-on: https://go-review.googlesource.com/c/go/+/176103
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-05-09 21:13:23 +00:00
Clément Chigot
3aacfce6cf runtime, cmd/dist, misc/cgo: enable c-archive for aix/ppc64
Change-Id: Ib9a40d5596f5735a00483e2d2db965402f05671b
Reviewed-on: https://go-review.googlesource.com/c/go/+/169120
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-04-02 16:03:24 +00:00
Keith Randall
b7f1777a70 runtime,cmd/ld: on darwin, create theads using libc
Replace thread creation with calls to the pthread
library in libc.

Update #17490

Change-Id: I1e19965c45255deb849b059231252fc6a7861d6c
Reviewed-on: https://go-review.googlesource.com/108679
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-04-30 02:41:03 +00:00
Tobias Klauser
01237b1362 runtime: parse auxv for page size and executable name on Solaris
Decode AT_PAGESZ to determine physPageSize and AT_SUN_EXECNAME for
os.Executable.

Change-Id: I6ff774ad9d76c68fc61eb307df58217c17fd578d
Reviewed-on: https://go-review.googlesource.com/104375
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-04-03 15:49:45 +00:00
Tobias Klauser
c7c01efd96 runtime: clean up libc_* definitions on Solaris
All functions defined in syscall2_solaris.go have the respective libc_*
var in syscall_solaris.go, except for libc_close. Move it from
os3_solaris.go

Remove unused libc_fstat.

Order go:cgo_import_dynamic and go:linkname lists in
syscall2_solaris.go alphabetically.

Change-Id: I9f12fa473cf1ae351448ac45597c82a67d799c31
Reviewed-on: https://go-review.googlesource.com/97736
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-03-01 07:31:53 +00:00
Tobias Klauser
1b1c8b34d1 runtime: remove unused getrlimit function
Follow CL 93655 which removed the (commented-out) usage of this
function.

Also remove unused constant _RLIMIT_AS and type rlimit.

Change-Id: Ifb6e6b2104f4c2555269f8ced72bfcae24f5d5e9
Reviewed-on: https://go-review.googlesource.com/94775
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2018-02-17 18:35:41 +00:00
Austin Clements
8693b4f095 runtime: remove unused memlimit function
Change-Id: Id057dcc85d64e5c670710fbab6cacd4b906cf594
Reviewed-on: https://go-review.googlesource.com/93655
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-02-13 22:35:47 +00:00
Austin Clements
193088b246 runtime: separate error result for mmap
Currently mmap returns an unsafe.Pointer that encodes OS errors as
values less than 4096. In practice this is okay, but it borders on
being really unsafe: for example, the value has to be checked
immediately after return and if stack copying were ever to observe
such a value, it would panic. It's also not remotely idiomatic.

Fix this by making mmap return a separate pointer value and error,
like a normal Go function.

Updates #22218.

Change-Id: Iefd965095ffc82cc91118872753a5d39d785c3a6
Reviewed-on: https://go-review.googlesource.com/71270
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-18 19:22:08 +00:00
Austin Clements
eff2b2620d runtime: make it possible to exit Go-created threads
Currently, threads created by the runtime exist until the whole
program exits. For #14592 and #20395, we want to be able to exit and
clean up threads created by the runtime. This commit implements that
mechanism.

The main difficulty is how to clean up the g0 stack. In cgo mode and
on Solaris and Windows where the OS manages thread stacks, we simply
arrange to return from mstart and let the system clean up the thread.
If the runtime allocated the g0 stack, then we use a new exitThread
syscall wrapper that arranges to clear a flag in the M once the stack
can safely be reaped and call the thread termination syscall.

exitThread is based on the existing exit1 wrapper, which was always
meant to terminate the calling thread. However, exit1 has never been
used since it was introduced 9 years ago, so it was broken on several
platforms. exitThread also has the additional complication of having
to flag that the stack is unused, which requires some tricks on
platforms that use the stack for syscalls.

This still leaves the problem of how to reap the unused g0 stacks. For
this, we move the M from allm to a new freem list as part of the M
exiting. Later, allocm scans the freem list, finds Ms that are marked
as done with their stack, removes these from the list and frees their
g0 stacks. This also allows these Ms to be garbage collected.

This CL does not yet use any of this functionality. Follow-up CLs
will. Likewise, there are no new tests in this CL because we'll need
follow-up functionality to test it.

Change-Id: Ic851ee74227b6d39c6fc1219fc71b45d3004bc63
Reviewed-on: https://go-review.googlesource.com/46037
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-10-11 17:47:18 +00:00
Austin Clements
87e48c5afd runtime, cmd/compile: rename memclr -> memclrNoHeapPointers
Since barrier-less memclr is only safe in very narrow circumstances,
this commit renames memclr to avoid accidentally calling memclr on
typed memory. This can cause subtle, non-deterministic bugs, so it's
worth some effort to prevent. In the near term, this will also prevent
bugs creeping in from any concurrent CLs that add calls to memclr; if
this happens, whichever patch hits master second will fail to compile.

This also adds the other new memclr variants to the compiler's
builtin.go to minimize the churn on that binary blob. We'll use these
in future commits.

Updates #17503.

Change-Id: I00eead049f5bd35ca107ea525966831f3d1ed9ca
Reviewed-on: https://go-review.googlesource.com/31369
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
2016-10-28 18:20:33 +00:00
Ian Lance Taylor
6c13a1db2e runtime: don't call cgocallback from signal handler
Calling cgocallback from a signal handler can fail when using the race
detector. Calling cgocallback will lead to a call to newextram which
will call oneNewExtraM which will call racegostart. The racegostart
function will set up some race detector data structures, and doing that
will sometimes call the C memory allocator. If we are running the signal
handler from a signal that interrupted the C memory allocator, we will
crash or hang.

Instead, change the signal handler code to call needm and dropm. The
needm function will grab allocated m and g structures and initialize the
g to use the current stack--the signal stack. That is all we need to
safely call code that allocates memory and checks whether it needs to
split the stack. This may temporarily leave us with no m available to
run a cgo callback, but that is OK in this case since the code we call
will quickly either crash or call dropm to return the m.

Implementing this required changing some of the setSignalstackSP
functions to avoid a write barrier. These functions never need a write
barrier but in some cases generated one anyhow because on some systems
the ss_sp field is a pointer.

Change-Id: I3893f47c3a66278f85eab7f94c1ab11d4f3be133
Reviewed-on: https://go-review.googlesource.com/30218
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
2016-10-05 13:21:49 +00:00
Ian Lance Taylor
eb268cb321 runtime: minor simplifications to signal code
Change setsig, setsigstack, getsig, raise, raiseproc to take uint32 for
signal number parameter, as that is the type mostly used for signal
numbers.  Same for dieFromSignal, sigInstallGoHandler, raisebadsignal.

Remove setsig restart parameter, as it is always either true or
irrelevant.

Don't check the handler in setsigstack, as the only caller does that
anyhow.

Don't bother to convert the handler from sigtramp to sighandler in
getsig, as it will never be called when the handler is sigtramp or
sighandler.

Don't check the return value from rt_sigaction in the GNU/Linux version
of setsigstack; no other setsigstack checks it, and it never fails.

Change-Id: I6bbd677e048a77eddf974dd3d017bc3c560fbd48
Reviewed-on: https://go-review.googlesource.com/29953
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-28 13:12:47 +00:00
Ian Lance Taylor
fdc167164e runtime: remove sigmask type, use sigset instead
The OS-independent sigmask type was not pulling its weight. Replace it
with the OS-dependent sigset type. This requires adding an OS-specific
sigaddset function, but permits removing the OS-specific sigmaskToSigset
function.

Change-Id: I43307b512b0264ec291baadaea902f05ce212305
Reviewed-on: https://go-review.googlesource.com/29950
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-27 21:33:44 +00:00
Ian Lance Taylor
e2e11f02a4 runtime: unify Unix implementations of unminit
Change-Id: I2cbb13eb85876ad05a52cbd498a9b86e7a28899c
Reviewed-on: https://go-review.googlesource.com/29772
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-26 19:33:26 +00:00
Ian Lance Taylor
ac24388e5e runtime: merge setting new signal mask in minit
All the variants that sets the new signal mask in minit do the same
thing, so merge them. This requires an OS-specific sigdelset function;
the function already exists for linux, and is now added for other OS's.

Change-Id: Ie96f6f02e2cf09c43005085985a078bd9581f670
Reviewed-on: https://go-review.googlesource.com/29771
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-09-26 18:29:32 +00:00
Ian Lance Taylor
c2735039f3 runtime: unify sigtrampgo
Combine the various versions of sigtrampgo into a single function in
signal_unix.go. This requires defining a fixsigcode method on sigctxt
for all operating systems; it only does something on Darwin. This also
requires changing the darwin/amd64 signal handler to call sigreturn
itself, rather than relying on sigtrampgo to call sigreturn for it. We
can then drop the Darwin sigreturn function, as it is no longer used.

Change-Id: I5a0b9d2d2c141957e151b41e694efeb20e4b4b9a
Reviewed-on: https://go-review.googlesource.com/29761
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-26 17:22:42 +00:00
Ian Lance Taylor
d15295c679 runtime: unify handling of alternate signal stack
Change all Unix systems to use stackt for the alternate signal
stack (some were using sigaltstackt). Add OS-specific setSignalstackSP
function to handle different types for ss_sp field, and unify all
OS-specific signalstack functions into one. Unify handling of alternate
signal stack in OS-specific minit and sigtrampgo functions via new
functions minitSignalstack and setGsignalStack.

Change-Id: Idc316dc69b1dd725717acdf61a1cd8b9f33ed174
Reviewed-on: https://go-review.googlesource.com/29757
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-26 04:07:31 +00:00
Ian Lance Taylor
ab552aa3b6 runtime: unify some signal handling functions
Unify the OS-specific versions of msigsave, msigrestore, sigblock,
updatesigmask, and unblocksig into single versions in signal_unix.go.
To do this, make sigprocmask work the same way on all systems, which
required adding a definition of sigprocmask for linux and openbsd.
Also add a single OS-specific function sigmaskToSigset.

Change-Id: I7cbf75131dddb57eeefe648ef845b0791404f785
Reviewed-on: https://go-review.googlesource.com/29689
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-09-24 01:39:48 +00:00
Austin Clements
276a52de55 runtime: fetch physical page size from the OS
Currently the physical page size assumed by the runtime is hard-coded.
On Linux the runtime at least fetches the OS page size during init and
sanity checks against the hard-coded value, but they may still differ.
On other OSes we wouldn't even notice.

Add support on all OSes to fetch the actual OS physical page size
during runtime init and lift the sanity check of PhysPageSize from the
Linux init code to general malloc init. Currently this is the only use
of the retrieved page size, but we'll add more shortly.

Updates #12480 and #10180.

Change-Id: I065f2834bc97c71d3208edc17fd990ec9058b6da
Reviewed-on: https://go-review.googlesource.com/25050
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
2016-09-06 21:05:50 +00:00
Josh Bleecher Snyder
71ab9fa312 all: fix assembly vet issues
Add missing function prototypes.
Fix function prototypes.
Use FP references instead of SP references.
Fix variable names.
Update comments.
Clean up whitespace. (Not for vet.)

All fairly minor fixes to make vet happy.

Updates #11041

Change-Id: Ifab2cdf235ff61cdc226ab1d84b8467b5ac9446c
Reviewed-on: https://go-review.googlesource.com/27713
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-08-25 18:52:31 +00:00
Ian Lance Taylor
c7ae41e577 runtime: better error message for newosproc failure
If creating a new thread fails with EAGAIN, point the user at ulimit.

Fixes #15476.

Change-Id: Ib36519614b5c72776ea7f218a0c62df1dd91a8ea
Reviewed-on: https://go-review.googlesource.com/24570
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-06-29 01:37:19 +00:00
Brad Fitzpatrick
5fea2ccc77 all: single space after period.
The tree's pretty inconsistent about single space vs double space
after a period in documentation. Make it consistently a single space,
per earlier decisions. This means contributors won't be confused by
misleading precedence.

This CL doesn't use go/doc to parse. It only addresses // comments.
It was generated with:

$ perl -i -npe 's,^(\s*// .+[a-z]\.)  +([A-Z]),$1 $2,' $(git grep -l -E '^\s*//(.+\.)  +([A-Z])')
$ go test go/doc -update

Change-Id: Iccdb99c37c797ef1f804a94b22ba5ee4b500c4f7
Reviewed-on: https://go-review.googlesource.com/20022
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Dave Day <djd@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-02 00:13:47 +00:00
Josh Bleecher Snyder
e43c74a0d8 all: use cannot instead of can not
You can not use cannot, but you cannot spell cannot can not.

Change-Id: I2f0971481a460804de96fd8c9e46a9cc62a3fc5b
Reviewed-on: https://go-review.googlesource.com/19772
Reviewed-by: Rob Pike <r@golang.org>
2016-02-21 15:35:50 +00:00
Ian Lance Taylor
c93193aec0 runtime: return errno value from Solaris mmap as expected
The code in mem_bsd.go expects that when mmap fails it will return a
positive errno value.  This fixes the Solaris implementation of mmap to
work as expected.

Change-Id: Id1c34a9b916e8dc955ced90ea2f4af8321d92265
Reviewed-on: https://go-review.googlesource.com/19477
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2016-02-12 19:20:19 +00:00
Ian Lance Taylor
28f9d96c75 runtime: remove erroneous go:noescape declaration
Change-Id: I6b1dc789e54a385c958961e7ba16bfd9d0f3b313
Reviewed-on: https://go-review.googlesource.com/18629
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-01-14 17:11:48 +00:00
Ian Lance Taylor
efd93a412e runtime: minimize time between lockextra/unlockextra
This doesn't fix a bug, but may improve performance in programs that
have many concurrent calls from C to Go.  The old code made several
system calls between lockextra and unlockextra.  That could be happening
while another thread is spinning acquiring lockextra.  This changes the
code to not make any system calls while holding the lock.

Change-Id: I50576478e478670c3d6429ad4e1b7d80f98a19d8
Reviewed-on: https://go-review.googlesource.com/18548
Reviewed-by: Russ Cox <rsc@golang.org>
2016-01-14 05:55:43 +00:00
Ian Lance Taylor
21b4f234c7 runtime: for c-archive/c-shared, install signal handlers synchronously
The previous behaviour of installing the signal handlers in a separate
thread meant that Go initialization raced with non-Go initialization if
the non-Go initialization also wanted to install signal handlers.  Make
installing signal handlers synchronous so that the process-wide behavior
is predictable.

Update #9896.

Change-Id: Ice24299877ec46f8518b072a381932d273096a32
Reviewed-on: https://go-review.googlesource.com/18150
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-01-09 00:58:38 +00:00
Ian Lance Taylor
84a95be922 runtime: add nowritebarrierrec to funcs called at signal time
Also nosplit where needed.

Change-Id: I1e3f6f8f76df9ee7e87ed1b8560cef145928314c
Reviewed-on: https://go-review.googlesource.com/18395
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-01-08 17:26:28 +00:00
Ian Lance Taylor
a7cad52e04 runtime: preserve signal stack when calling Go on C thread
When calling a Go function on a C thread, if the C thread already has an
alternate signal stack, use that signal stack instead of installing a
new one.

Update #9896.

Change-Id: I62aa3a6a4a1dc4040fca050757299c8e6736987c
Reviewed-on: https://go-review.googlesource.com/18108
Reviewed-by: Russ Cox <rsc@golang.org>
2016-01-06 23:11:42 +00:00
Ian Lance Taylor
956535f5cb runtime: implement setsigstack for Solaris
Change-Id: I0280d478b7d0a59d8e2082aa87fab6d7d9f36a18
Reviewed-on: https://go-review.googlesource.com/18158
Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>
2016-01-04 16:33:58 +00:00