Commit Graph

61 Commits

Author SHA1 Message Date
Austin Clements 60a9e5d613 runtime: ensure abort actually crashes the process
On all non-x86 arches, runtime.abort simply reads from nil.
Unfortunately, if this happens on a user stack, the signal handler
will dutifully turn this into a panicmem, which lets user defers run
and which user code can even recover from.

To fix this, add an explicit check to the signal handler that turns
faults in abort into hard crashes directly in the signal handler. This
has the added benefit of giving a register dump at the abort point.

Change-Id: If26a7f13790745ee3867db7f53b72d8281176d70
Reviewed-on: https://go-review.googlesource.com/93661
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-08 22:55:55 +00:00
Ian Lance Taylor 419c06455a runtime: get traceback from VDSO code
Currently if a profiling signal arrives while executing within a VDSO
the profiler will report _ExternalCode, which is needlessly confusing
for a pure Go program. Change the VDSO calling code to record the
caller's PC/SP, so that we can do a traceback from that point. If that
fails for some reason, report _VDSO rather than _ExternalCode, which
should at least point in the right direction.

This adds some instructions to the code that calls the VDSO, but the
slowdown is reasonably negligible:

name                                  old time/op  new time/op  delta
ClockVDSOAndFallbackPaths/vDSO-8      40.5ns ± 2%  41.3ns ± 1%  +1.85%  (p=0.002 n=10+10)
ClockVDSOAndFallbackPaths/Fallback-8  41.9ns ± 1%  43.5ns ± 1%  +3.84%  (p=0.000 n=9+9)
TimeNow-8                             41.5ns ± 3%  41.5ns ± 2%    ~     (p=0.723 n=10+10)

Fixes #24142

Change-Id: Iacd935db3c4c782150b3809aaa675a71799b1c9c
Reviewed-on: https://go-review.googlesource.com/97315
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2018-03-07 23:35:25 +00:00
Austin Clements ebe38b867c runtime: fail silently if we unwind over sigpanic into C code
If we're running C code and the code panics, the runtime will inject a
call to sigpanic into the C code just like it would into Go code.
However, the return PC from this sigpanic will be in C code. We used
to silently abort the traceback if we didn't recognize a return PC, so
this went by quietly. Now we're much louder because in general this is
a bad thing. However, in this one particular case, it's fine, so if
we're in cgo and are looking at the return PC of sigpanic, silence the
debug output.

Fixes #23576.

Change-Id: I03d0c14d4e4d25b29b1f5804f5e9ccc4f742f876
Reviewed-on: https://go-review.googlesource.com/90896
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-01-31 02:13:21 +00:00
Austin Clements dbd8f3d739 runtime: print hexdump on traceback failure
Currently, if anything goes wrong when printing a traceback, we simply
cut off the traceback without any further diagnostics. Unfortunately,
right now, we have a few issues that are difficult to debug because
the traceback simply cuts off (#21431, #23484).

This is an attempt to improve the debuggability of traceback failure
by printing a diagnostic message plus a hex dump around the failed
traceback frame when something goes wrong.

The failures look like:

goroutine 5 [running]:
runtime: unexpected return pc for main.badLR2 called from 0xbad
stack: frame={sp:0xc42004dfa8, fp:0xc42004dfc8} stack=[0xc42004d800,0xc42004e000)
000000c42004dea8:  0000000000000001  0000000000000001
000000c42004deb8:  000000c42004ded8  000000c42004ded8
000000c42004dec8:  0000000000427eea <runtime.dopanic+74>  000000c42004ded8
000000c42004ded8:  000000000044df70 <runtime.dopanic.func1+0>  000000c420001080
000000c42004dee8:  0000000000427b21 <runtime.gopanic+961>  000000c42004df08
000000c42004def8:  000000c42004df98  0000000000427b21 <runtime.gopanic+961>
000000c42004df08:  0000000000000000  0000000000000000
000000c42004df18:  0000000000000000  0000000000000000
000000c42004df28:  0000000000000000  0000000000000000
000000c42004df38:  0000000000000000  000000c420001080
000000c42004df48:  0000000000000000  0000000000000000
000000c42004df58:  0000000000000000  0000000000000000
000000c42004df68:  000000c4200010a0  0000000000000000
000000c42004df78:  00000000004c6400  00000000005031d0
000000c42004df88:  0000000000000000  0000000000000000
000000c42004df98:  000000c42004dfb8  00000000004ae7d9 <main.badLR2+73>
000000c42004dfa8: <00000000004c6400  00000000005031d0
000000c42004dfb8:  000000c42004dfd0 !0000000000000bad
000000c42004dfc8: >0000000000000000  0000000000000000
000000c42004dfd8:  0000000000451821 <runtime.goexit+1>  0000000000000000
000000c42004dfe8:  0000000000000000  0000000000000000
000000c42004dff8:  0000000000000000
main.badLR2(0x0)
	/go/src/runtime/testdata/testprog/badtraceback.go:42 +0x49

For #21431, #23484.

Change-Id: I8718fc76ced81adb0b4b0b4f2293f3219ca80786
Reviewed-on: https://go-review.googlesource.com/89016
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-01-22 21:51:29 +00:00
Ian Lance Taylor 29cb57c5bd runtime: don't use MAP_STACK in SigStack test
On DragonFly mmap with MAP_STACK returns the top of the region, not
the bottom. Rather than try to cope, just don't use the flag anywhere.

Fixes #23061

Change-Id: Ib5df4dd7c934b3efecfc4bc87f8989b4c37555d7
Reviewed-on: https://go-review.googlesource.com/83035
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2017-12-09 01:21:32 +00:00
Austin Clements ce5292a1f2 runtime: use MAP_ANON in sigstack check
MAP_ANON is the deprecated but more portable spelling of
MAP_ANONYMOUS. Use MAP_ANON to un-break the Darwin 10.10 builder.

Updates #22930.

Change-Id: Iedd6232b94390b3b2a7423c45cdcb25c1a5b3323
Reviewed-on: https://go-review.googlesource.com/81615
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-12-01 21:52:02 +00:00
Austin Clements 292558be02 runtime: restore the Go-allocated signal stack in unminit
Currently, when we minit on a thread that already has an alternate
signal stack (e.g., because the M was an extram being used for a cgo
callback, or to handle a signal on a C thread, or because the
platform's libc always allocates a signal stack like on Android), we
simply drop the Go-allocated gsignal stack on the floor.

This is a problem for Ms on the extram list because those Ms may later
be reused for a different thread that may not have its own alternate
signal stack. On tip, this manifests as a crash in sigaltstack because
we clear the gsignal stack bounds in unminit and later try to use
those cleared bounds when we re-minit that M. On 1.9 and earlier, we
didn't clear the bounds, so this manifests as running more than one
signal handler on the same signal stack, which could lead to arbitrary
memory corruption.

This CL fixes this problem by saving the Go-allocated gsignal stack in
a new field in the m struct when overwriting it with a system-provided
signal stack, and then restoring the original gsignal stack in
unminit.

This CL is designed to be easy to back-port to 1.9. It won't quite
cherry-pick cleanly, but it should be sufficient to simply ignore the
change in mexit (which didn't exist in 1.9).

Now that we always have a place to stash the original signal stack in
the m struct, there are some simplifications we can make to the signal
stack handling. We'll do those in a later CL.

Fixes #22930.

Change-Id: I55c5a6dd9d97532f131146afdef0b216e1433054
Reviewed-on: https://go-review.googlesource.com/81476
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-12-01 20:20:45 +00:00
Alex Brainman 923299a6b8 cmd/link: restore windows stack commit size back to 4KB
CL 49331 increased windows stack commit size to 2MB by mistake.
Revert that change.

Fixes #22439

Change-Id: I919e549e87da326f4ba45890b4d32f6d7046186f
Reviewed-on: https://go-review.googlesource.com/74490
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2017-11-03 00:09:40 +00:00
Russ Cox 94471f6324 runtime: shorten tests in all.bash
This cuts 23 seconds from all.bash on my MacBook Pro.

Change-Id: Ibc4d7c01660b9e9ebd088dd55ba993f0d7ec6aa3
Reviewed-on: https://go-review.googlesource.com/73991
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-31 13:20:27 +00:00
Austin Clements 4f34a52913 runtime: terminate locked OS thread if its goroutine exits
runtime.LockOSThread is sometimes used when the caller intends to put
the OS thread into an unusual state. In this case, we never want to
return this thread to the runtime thread pool. However, currently
exiting the goroutine implicitly unlocks its OS thread.

Fix this by terminating the locked OS thread when its goroutine exits,
rather than simply returning it to the pool.

Fixes #20395.

Change-Id: I3dcec63b200957709965f7240dc216fa84b62ad9
Reviewed-on: https://go-review.googlesource.com/46038
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2017-10-11 17:47:21 +00:00
Elias Naur c3189cee71 runtime: forward crashing signals to late handlers
CL 49590 made it possible for external signal handlers to catch
signals from a crashing Go process. This CL extends that support
to handlers registered after the Go runtime has initialized.

Updates #20392 (and possibly fix it).

Change-Id: I18eccd5e958a505f4d1782a7fc51c16bd3a4ff9c
Reviewed-on: https://go-review.googlesource.com/57291
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-08-29 07:40:19 +00:00
Elias Naur 5500c9ce27 runtime: when dying from a signal use the previous signal handler
Before this CL, whenever the Go runtime wanted to kill its own
process with a signal dieFromSignal would reset the signal handler
to _SIG_DFL.

Unfortunately, if any signal handler were installed before the Go
runtime initialized, it wouldn't be invoked either.

Instead, use whatever signal handler was installed before
initialization.

The motivating use case is Crashlytics on Android. Before this CL,
Crashlytics would not consider a crash from a panic() since the
corresponding SIGABRT never reached its signal handler.

Updates #11382
Updates #20392 (perhaps even fixes it)
Fixes #19389

Change-Id: I0c8633329433b45cbb3b16571bea227e38e8be2e
Reviewed-on: https://go-review.googlesource.com/49590
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-08-10 10:08:17 +00:00
Ian Lance Taylor 93870aeee9 runtime: get more info for TestCgoSignalDeadlock failures
Updates #18598

Change-Id: I13c60124714cf9d1537efa0a7dd1e6a0fed9ae5b
Reviewed-on: https://go-review.googlesource.com/46723
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-06-27 00:34:53 +00:00
Ian Lance Taylor 03a4a5c988 runtime: don't run TestCgoNumGoroutine on Windows or Plan 9
The test requires pthreads.

Fixes #20666.

Change-Id: Icb2400250a80cdad6680cd1ef6c18ef7343d5e29
Reviewed-on: https://go-review.googlesource.com/45701
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-06-14 17:28:02 +00:00
Ian Lance Taylor df0892cbf8 runtime, syscall: reset signal handlers to default in child
Block all signals during a fork. In the parent process, after the
fork, restore the signal mask. In the child process, reset all
currently handled signals to the default handler, and then restore the
signal mask.

The effect of this is that the child will be operating using the same
signal regime as the program it is about to exec, as exec resets all
non-ignored signals to the default, and preserves the signal mask.

We do this so that in the case of a signal sent to the process group,
the child process will not try to run a signal handler while in the
precarious state after a fork.

Fixes #18600.

Change-Id: I9f39aaa3884035908d687ee323c975f349d5faaa
Reviewed-on: https://go-review.googlesource.com/45471
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2017-06-14 14:00:56 +00:00
Austin Clements 4e7067cde4 runtime: mark extra M's G as dead when not in use
Currently the extra Ms created for cgo callbacks have a corresponding
G that's kept in syscall state with only a call to goexit on its
stack. This leads to confusing output from runtime.NumGoroutines and
in tracebacks:

goroutine 17 [syscall, locked to thread]:
runtime.goexit()
	.../src/runtime/asm_amd64.s:2197 +0x1

Fix this by putting this goroutine into state _Gdead when it's not in
use instead of _Gsyscall. To keep the goroutine counts correct, we
also add one to sched.ngsys while the goroutine is in _Gdead. The
effect of this is as if the goroutine simply doesn't exist when it's
not in use.

Fixes #16631.
Fixes #16714.

Change-Id: Ieae08a2febd4b3d00bef5c23fd6ca88fb2bb0087
Reviewed-on: https://go-review.googlesource.com/45030
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-06-07 02:13:51 +00:00
Ian Lance Taylor 2d86f49428 runtime: delay exiting while panic is running deferred functions
Try to avoid a race between the main goroutine exiting and a panic
occurring. Don't try too hard, to avoid hanging.

Updates #3934
Fixes #20018

Change-Id: I57a02b6d795d2a61f1cadd137ce097145280ece7
Reviewed-on: https://go-review.googlesource.com/41052
Reviewed-by: Austin Clements <austin@google.com>
2017-06-05 22:42:48 +00:00
David NewHamlet e19f184b8f runtime: use cpuset_getaffinity for runtime.NumCPU() on FreeBSD
In FreeBSD when run Go proc under a given sub-list of
processors(e.g. 'cpuset -l 0 ./a.out' in multi-core system),
runtime.NumCPU() still return all physical CPUs from sysctl
hw.ncpu instead of account from sub-list.

Fix by use syscall cpuset_getaffinity to account the number of sub-list.

Fixes #15206

Change-Id: If87c4b620e870486efa100685db5debbf1210a5b
Reviewed-on: https://go-review.googlesource.com/29341
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
2017-03-10 22:06:24 +00:00
Ian Lance Taylor 0949659952 runtime: add explicit (void) in C to avoid GCC 7 problem
This avoids errors like
    ./traceback.go:80:2: call of non-function C.f1

I filed https://gcc.gnu.org/PR79289 for the GCC problem. I think this
is a bug in GCC, and it may be fixed before the final GCC 7 release.
This CL is correct either way.

Fixes #18855.

Change-Id: I0785a7b7c5b1d0ca87b454b5eca9079f390fcbd4
Reviewed-on: https://go-review.googlesource.com/35919
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2017-01-30 19:27:49 +00:00
Michael Munday cfd89164bb all: make copyright headers consistent with one space after period
Continuation of CL 20111.

Change-Id: Ie2f62237e6ec316989c021de9b267cc9d6ee6676
Reviewed-on: https://go-review.googlesource.com/32830
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-11-04 20:46:25 +00:00
Quentin Smith 21c114e930 runtime/testdata/testprog: increase GCFairness2 timeout to 1s
OpenBSD's scheduler causes preemption to take 20+ms, so 30ms is not
enough time for 3 goroutines to run. This change continues to sleep for
30ms, but if it finds that the 3 goroutines have not run, it sleeps for
an additional 1s before declaring failure.

Updates #17712

Change-Id: I3e886e40d05192b7cb71b4f242af195836ef62a8
Reviewed-on: https://go-review.googlesource.com/32634
Reviewed-by: Rick Hudson <rlh@golang.org>
Run-TryBot: Quentin Smith <quentin@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-11-03 15:48:57 +00:00
Ian Lance Taylor d03e8b226c runtime: record current PC for SIGPROF on non-Go thread
If we get a SIGPROF on a non-Go thread, and the program has not called
runtime.SetCgoTraceback so we have no way to collect a stack trace, then
record a profile that is just the PC where the signal occurred. That
will at least point the user to the right area.

Retrieving the PC from the sigctxt in a signal handler on a non-G thread
required marking a number of trivial sigctxt methods as nosplit, and,
for extra safety, nowritebarrierrec.

The test shows that the existing test CgoPprofThread test does not test
the stack trace, just the profile signal. Leaving that for later.

Change-Id: I8f8f3ff09ac099fc9d9df94b5a9d210ffc20c4ab
Reviewed-on: https://go-review.googlesource.com/30252
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
2016-10-11 12:56:15 +00:00
Ian Lance Taylor e5421e21ef runtime: add threadprof tag for test that starts busy thread
The CgoExternalThreadSIGPROF test starts a thread at constructor time
that does a busy loop. That can throw off some other tests. So only
build that code if testprogcgo is built with the tag threadprof, and
adjust the tests that use that code to pass that build tag.

This revealed that the CgoPprofThread test was not testing what it
should have, as it never actually started the cpuHog thread. It was
passing because of the busy loop thread. Fix it to start the thread as
intended.

Change-Id: I087a9e4fc734a86be16a287456441afac5676beb
Reviewed-on: https://go-review.googlesource.com/30362
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-10-06 01:23:09 +00:00
Michael Munday f15f1ff46f runtime/testdata/testprogcgo: add explicit return value to signalThread
Should fix the clang builder.

Change-Id: I3ee34581b6a7ec902420de72a8a08a2426997782
Reviewed-on: https://go-review.googlesource.com/30363
Run-TryBot: Michael Munday <munday@ca.ibm.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-10-05 15:36:00 +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 7faf702396 runtime: avoid endless loop if printing the panic value panics
Change-Id: I56de359a5ccdc0a10925cd372fa86534353c6ca0
Reviewed-on: https://go-review.googlesource.com/30358
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-10-05 13:13:27 +00:00
David Crawshaw ed915ad421 runtime: use sched_yield instead of pthread_yield
Attempt to fix the linux-amd64-clang builder, which broke
with CL 29472.

Turns out pthread_yield is a non-portable Linux function, and
should have #define _GNU_SOURCE before #include <pthread.h>.
GCC doesn't complain about this, but Clang does:

	./raceprof.go:44:3: warning: implicit declaration of function 'pthread_yield' is invalid in C99 [-Wimplicit-function-declaration]

(Though the error, while explicable, certainly could be clearer.)

There is a portable POSIX equivalent, sched_yield, so this
CL uses it instead.

Change-Id: I58ca7a3f73a2b3697712fdb02e72a8027c391169
Reviewed-on: https://go-review.googlesource.com/29675
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-23 04:32:38 +00:00
Ian Lance Taylor 9d8522fdc7 cmd/compile: don't instrument copy and append in runtime
Instrumenting copy and append for the race detector changes them to call
different functions. In the runtime package the alternate functions are
not marked as nosplit. This caused a crash in the SIGPROF handler when
invoked on a non-Go thread in a program built with the race detector. In
some cases the handler can call copy, the race detector changed that to
a call to a non-nosplit function, the function tried to check the stack
guard, and crashed because it was running on a non-Go thread. The
SIGPROF handler is written carefully to avoid such problems, but hidden
function calls are difficult to avoid.

Fix this by changing the compiler to not instrument copy and append when
compiling the runtime package. Change the runtime package to add
explicit race checks for the only code I could find where copy is used
to write to user data (append is never used).

Change-Id: I11078a66c0aaa459a7d2b827b49f4147922050af
Reviewed-on: https://go-review.googlesource.com/29472
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
2016-09-22 23:37:17 +00:00
Ian Lance Taylor fe251d2581 runtime: remove unused function in test
Change-Id: I43f14cdd9eb4a1d5471fc88c1b4759ceb2c674cf
Reviewed-on: https://go-review.googlesource.com/24817
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-08-23 14:09:52 +00:00
Keith Randall e492d9f018 runtime: fix map iterator concurrent map check
We should check whether there is a concurrent writer at the
start of every mapiternext, not just in mapaccessK (which is
only called during certain map growth situations).

Tests turned off by default because they are inherently flaky.

Fixes #16278

Change-Id: I8b72cab1b8c59d1923bec6fa3eabc932e4e91542
Reviewed-on: https://go-review.googlesource.com/24749
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-08-16 21:52:44 +00:00
Josh Bleecher Snyder 6f74c0774c runtime: move printing of extra newline
No functional changes, makes vet happy.

Updates #11041

Change-Id: I59f3aba46d19b86d605508978652d76a1fe7ac7b
Reviewed-on: https://go-review.googlesource.com/27125
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-08-16 14:37:17 +00:00
Ian Lance Taylor 252eda470a cmd/pprof: don't use offset if we don't have a start address
The test is in the runtime package because there are other tests of
pprof there. At some point we should probably move them all into a pprof
testsuite.

Fixes #16128.

Change-Id: Ieefa40c61cf3edde11fe0cf04da1debfd8b3d7c0
Reviewed-on: https://go-review.googlesource.com/24274
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-06-21 01:44:38 +00:00
Ian Lance Taylor ea2ac3fe5f runtime: remove useless loop from CgoCCodeSIGPROF test program
I verified that the test fails if I undo the change that it tests for.

Updates #14732.

Change-Id: Ib30352580236adefae946450ddd6cd65a62b7cdf
Reviewed-on: https://go-review.googlesource.com/24151
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
2016-06-16 03:52:18 +00:00
Ian Lance Taylor 84d8aff94c runtime: collect stack trace if SIGPROF arrives on non-Go thread
Fixes #15994.

Change-Id: I5aca91ab53985ac7dcb07ce094ec15eb8ec341f8
Reviewed-on: https://go-review.googlesource.com/23891
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-06-13 21:43:19 +00:00
Ian Lance Taylor 3d037cfaf8 runtime: pass signal context to cgo traceback function
When doing a backtrace from a signal that occurs in C code compiled
without using -fasynchronous-unwind-tables, we have to rely on frame
pointers. In order to do that, the traceback function needs the signal
context to reliably pick up the frame pointer.

Change-Id: I7b45930fced01685c337d108e0f146057928f876
Reviewed-on: https://go-review.googlesource.com/23494
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-31 21:17:40 +00:00
Austin Clements 44497ebacb runtime: fix goroutine priority elevation
Currently it's possible for user code to exploit the high scheduler
priority of the GC worker in conjunction with the runnext optimization
to elevate a user goroutine to high priority so it will always run
even if there are other runnable goroutines.

For example, if a goroutine is in a tight allocation loop, the
following can happen:

1. Goroutine 1 allocates, triggering a GC.
2. G 1 attempts an assist, but fails and blocks.
3. The scheduler runs the GC worker, since it is high priority.
   Note that this also starts a new scheduler quantum.
4. The GC worker does enough work to satisfy the assist.
5. The GC worker readies G 1, putting it in runnext.
6. GC finishes and the scheduler runs G 1 from runnext, giving it
   the rest of the GC worker's quantum.
7. Go to 1.

Even if there are other goroutines on the run queue, they never get a
chance to run in the above sequence. This requires a confluence of
circumstances that make it unlikely, though not impossible, that it
would happen in "real" code. In the test added by this commit, we
force this confluence by setting GOMAXPROCS to 1 and GOGC to 1 so it's
easy for the test to repeated trigger GC and wake from a blocked
assist.

We fix this by making GC always put user goroutines at the end of the
run queue, instead of in runnext. This makes it so user code can't
piggy-back on the GC's high priority to make a user goroutine act like
it has high priority. The only other situation where GC wakes user
goroutines is waking all blocked assists at the end, but this uses the
global run queue and hence doesn't have this problem.

Fixes #15706.

Change-Id: I1589dee4b7b7d0c9c8575ed3472226084dfce8bc
Reviewed-on: https://go-review.googlesource.com/23172
Reviewed-by: Rick Hudson <rlh@golang.org>
2016-05-19 18:18:13 +00:00
Ian Lance Taylor 23a59ba17c runtime: deflake TestSignalExitStatus
The signal might get delivered to a different thread, and that thread
might not run again before the currently running thread returns and
exits. Sleep to give the other thread time to pick up the signal and
crash.

Not tested for all cases, but, optimistically:
Fixes #14063.

Change-Id: Iff58669ac6185ad91cce85e0e86f17497a3659fd
Reviewed-on: https://go-review.googlesource.com/23203
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
2016-05-18 04:08:08 +00:00
Brad Fitzpatrick 9628e6fd1d runtime/testdata/testprogcgo: fix Windows C compiler warning
Noticed and fix by Alex Brainman.

Tested in https://golang.org/cl/23005 (which makes all compiler
warnings fatal during development)

Fixes #15623

Change-Id: Ic19999fce8bb8640d963965cc328574efadd7855
Reviewed-on: https://go-review.googlesource.com/23010
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
2016-05-10 23:11:44 +00:00
Ian Lance Taylor 34f97d28d2 runtime: put tracebackctxt C functions in .c file
Since tracebackctxt.go uses //export functions, the C functions can't be
externally visible in the C comment. The code was using attributes to
work around that, but that failed on Windows.

Change-Id: If4449fd8209a8998b4f6855ea89e5db1471b2981
Reviewed-on: https://go-review.googlesource.com/22786
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-05 01:19:18 +00:00
Ian Lance Taylor 84e808043f runtime: use cgo traceback for SIGPROF
If we collected a cgo traceback when entering the SIGPROF signal
handler, record it as part of the profiling stack trace.

This serves as the promised test for https://golang.org/cl/21055 .

Change-Id: I5f60cd6cea1d9b7c3932211483a6bfab60ed21d2
Reviewed-on: https://go-review.googlesource.com/22650
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2016-05-04 00:08:19 +00:00
Emmanuel Odeke 53fd522c0d all: make copyright headers consistent with one space after period
Follows suit with https://go-review.googlesource.com/#/c/20111.

Generated by running
$ grep -R 'Go Authors.  All' * | cut -d":" -f1 | while read F;do perl -pi -e 's/Go
Authors.  All/Go Authors. All/g' $F;done

The code in cmd/internal/unvendor wasn't changed.

Fixes #15213

Change-Id: I4f235cee0a62ec435f9e8540a1ec08ae03b1a75f
Reviewed-on: https://go-review.googlesource.com/21819
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-02 13:43:18 +00:00
Ian Lance Taylor 5f9a870bf1 cmd/cgo, runtime, runtime/cgo: use cgo context function
Add support for the context function set by runtime.SetCgoTraceback.
The context function was added in CL 17761, without support.
This CL is the support.

This CL has not been tested for real C code, as a working context
function for C code requires unwind support that does not seem to exist.
I wanted to get the CL out before the freeze.

I apologize for the length of this CL.  It's mostly plumbing, but
unfortunately the plumbing is processor-specific.

Change-Id: I8ce11a0de9b3dafcc29efd2649d776e93bff0e90
Reviewed-on: https://go-review.googlesource.com/22508
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-29 22:07:36 +00:00
Christopher Nelson ed8f0e5c33 cmd/go: fix -buildmode=c-archive should work on windows
Add supporting code for runtime initialization, including both
32- and 64-bit x86 architectures.

Add .ctors section on Windows to PE .o files, and INITENTRY to .ctors
section to plug in to the GCC C/C++ startup initialization mechanism.
This allows the Go runtime to initialize itself. Add .text section
symbol for .ctor relocations. Note: This is unlikely to be useful for
MSVC-based toolchains.

Fixes #13494

Change-Id: I4286a96f70e5f5228acae88eef46e2bed95813f3
Reviewed-on: https://go-review.googlesource.com/18057
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
2016-04-04 03:38:25 +00:00
Ian Lance Taylor ea306ae625 runtime: support symbolic backtrace of C code in a cgo crash
The new function runtime.SetCgoTraceback may be used to register stack
traceback and symbolizer functions, written in C, to do a stack
traceback from cgo code.

There is a sample implementation of runtime.SetCgoSymbolizer at
github.com/ianlancetaylor/cgosymbolizer.  Just importing that package is
sufficient to get symbolic C backtraces.

Currently only supported on linux/amd64.

Change-Id: If96ee2eb41c6c7379d407b9561b87557bfe47341
Reviewed-on: https://go-review.googlesource.com/17761
Reviewed-by: Austin Clements <austin@google.com>
2016-04-01 04:13:44 +00:00
Ian Lance Taylor b354f91417 runtime: limit TestCgoCCodeSIGPROF test to 1 second
Still fails about 20% of the time on my laptop.

Fixes #14766.

Change-Id: I169ab728c6022dceeb91188f5ad466ed6413c062
Reviewed-on: https://go-review.googlesource.com/20590
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-11 06:43:01 +00:00
Ian Lance Taylor 1716162a9a runtime: fix off-by-one error finding module for PC
Also fix compiler-invoked panics to avoid a confusing "malloc deadlock"
crash if they are invoked while executing the runtime.

Fixes #14599.

Change-Id: I89436abcbf3587901909abbdca1973301654a76e
Reviewed-on: https://go-review.googlesource.com/20219
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-03-04 21:06:31 +00:00
Brad Fitzpatrick 519474451a all: make copyright headers consistent with one space after period
This is a subset of https://golang.org/cl/20022 with only the copyright
header lines, so the next CL will be smaller and more reviewable.

Go policy has been single space after periods in comments for some time.

The copyright header template at:

    https://golang.org/doc/contribute.html#copyright

also uses a single space.

Make them all consistent.

Change-Id: Icc26c6b8495c3820da6b171ca96a74701b4a01b0
Reviewed-on: https://go-review.googlesource.com/20111
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-01 23:34:33 +00:00
Ian Lance Taylor 8d94b9b820 runtime: more deflaking of TestCgoCheckBytes
Fixes #14519.

Change-Id: I8f78f67a463e6467e09df90446f7ebd28789d6c9
Reviewed-on: https://go-review.googlesource.com/19933
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
2016-02-26 19:20:47 +00:00
Shenghou Ma e960302410 runtime: when crash with panic, call user Error/String methods before freezing the world
Fixes #14432.

Change-Id: I0a92ef86de95de39217df9a664d8034ef685a906
Reviewed-on: https://go-review.googlesource.com/19792
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-21 20:18:51 +00:00
Ian Lance Taylor c8e7b34b59 runtime: skip cgo check for non-pointer slice elements
Fixes #14387.

Change-Id: Icc98be80f549c5e1f55c5e693bfea97b456a6c41
Reviewed-on: https://go-review.googlesource.com/19621
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-02-19 16:07:27 +00:00