The test for the framepointer experiment flag is cheaper and more
branch-predictable than the other parts of this conditional, so move
it first. This is also more readable.
(Originally, the flag check required parsing the experiments string,
which is why it was done last. Now that flag is cached.)
Change-Id: I84e00fa7e939e9064f0fa0a4a6fe00576dd61457
Reviewed-on: https://go-review.googlesource.com/3782
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Previously, we checked for a saved frame pointer by looking for a
2*ptrSize gap between the argument pointer and the locals pointer.
The intent of this check was to look for a two stack slot gap (caller
IP and saved frame pointer), but stack slots are regSize, not ptrSize.
Correct this by checking instead for a 2*regSize gap.
On most platforms, this made no difference because ptrSize==regSize.
However, on amd64p32 (nacl), the saved frame pointer check incorrectly
fired when there was no saved frame pointer because the one stack slot
for the caller IP left an 8 byte gap, which is 2*ptrSize (but not
2*regSize) on amd64p32.
Fixes#9760.
Change-Id: I6eedcf681fe5bf2bf924dde8a8f2d9860a4d758e
Reviewed-on: https://go-review.googlesource.com/3781
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This change adds support for case insensitivity of DNS labels to
built-in DNS stub resolver as described in RFC 4343.
Fixes#9215.
Change-Id: Ia752fe71866a3bfa3ea08371985b799d419ddea3
Reviewed-on: https://go-review.googlesource.com/3685
Reviewed-by: Ian Lance Taylor <iant@golang.org>
We already checked for the prefix with strings.HasPrefix
Change-Id: I33852fd19ffa92aa33b75b94b4bb505f4043a54a
Reviewed-on: https://go-review.googlesource.com/3691
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Fourth time's the charm.
Actually this doesn't fix the build, there is a
crash after go_bootstrap is compiled which looks
like it is related to auxv parsing.
Change-Id: Id00e2dfbe7bae42856f996065d3fb90b820e29a8
Reviewed-on: https://go-review.googlesource.com/3610
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Add memprofrate as a value recognized in GODEBUG. The
value provided is used as the new setting for
runtime.MemProfileRate, allowing the user to
adjust memory profiling.
Change-Id: If129a247683263b11e2dd42473cf9b31280543d5
Reviewed-on: https://go-review.googlesource.com/3450
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This adds a "framepointer" GOEXPERIMENT that that makes the amd64
toolchain maintain base pointer chains in the same way that gcc
-fno-omit-frame-pointer does. Go doesn't use these saved base
pointers, but this does enable external tools like Linux perf and
VTune to unwind Go stacks when collecting system-wide profiles.
This requires support in the compilers to not clobber BP, support in
liblink for generating the BP-saving function prologue and unwinding
epilogue, and support in the runtime to save BPs across preemption, to
skip saved BPs during stack unwinding and, and to adjust saved BPs
during stack moving.
As with other GOEXPERIMENTs, everything from the toolchain to the
runtime must be compiled with this experiment enabled. To do this,
run make.bash (or all.bash) with GOEXPERIMENT=framepointer.
Change-Id: I4024853beefb9539949e5ca381adfdd9cfada544
Reviewed-on: https://go-review.googlesource.com/2992
Reviewed-by: Russ Cox <rsc@golang.org>
Any place that clobbers BP in the runtime can potentially interfere
with frame pointer unwinding with GOEXPERIMENT=framepointer. This
change eliminates uses of BP in the runtime to address this problem.
We have spare registers everywhere this occurs, so there's no downside
to eliminating BP. Where possible, this uses the same new register as
the amd64p32 runtime, which doesn't use BP due to restrictions placed
on it by NaCL.
One nice side effect of this is that it will let perf/VTune unwind the
call stack even through a call to systemstack, which will let us get
really good call graphs from the garbage collector.
Change-Id: I0ffa14cb4dd2b613a7049b8ec59df37c52286212
Reviewed-on: https://go-review.googlesource.com/3390
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
m.gcing has become overloaded to mean "don't preempt this g" in
general. Once the garbage collector is preemptible, the one thing it
*won't* mean is that we're in the garbage collector.
So, rename gcing to "preemptoff" and make it a string giving a reason
that preemption is disabled. gcing was never set to anything but 0 or
1, so we don't have to worry about there being a stack of reasons.
Change-Id: I4337c29e8e942e7aa4f106fc29597e1b5de4ef46
Reviewed-on: https://go-review.googlesource.com/3660
Reviewed-by: Russ Cox <rsc@golang.org>
Commit 656be31 replaced onM with systemstack, but missed updating a
few comments that still referred to onM. Update these.
Change-Id: I0efb017e9a66ea0adebb6e1da6e518ee11263f69
Reviewed-on: https://go-review.googlesource.com/3664
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
9g generates needlessly complex code for small copies. There are a
few other things that need to be improved about the copy code, so for
now just note the problem.
Change-Id: I0f1de4b2f9197a2635e27cc4b91ecf7a6c11f457
Reviewed-on: https://go-review.googlesource.com/3665
Reviewed-by: Russ Cox <rsc@golang.org>
In stripCommonPrefix, the prefix was correctly calculated in all cases,
except one. That unhandled case is when there are more than 2 lines,
but all lines are blank (other than the first and last lines,
which contain /* and */ respectively).
This change detects that case and correctly sets the prefix calculated
from the last line. This is consistent with the (correct) behavior
that happens when there's at least one non-blank line.
That fixes issue #9751 that occurs for problematic input,
where cmd/gofmt and go/source would insert extra indentation on
every format operation. It also allows go/printer itself to print
such parsed files in an expected way.
Fixes#9751.
Change-Id: Id3dfb945beb59ffad3705085a3c285fca30a5f87
Reviewed-on: https://go-review.googlesource.com/3684
Reviewed-by: Robert Griesemer <gri@golang.org>
Since CL 3676, the TestMkdirAllAtSlash test
depends on syscall.EROFS, which isn't defined
on Plan 9.
This change works around this issue by
defining a system dependent isReadonlyError
function.
Change-Id: If972fd2fe4828ee3bcb8537ea7f4ba29f7a87619
Reviewed-on: https://go-review.googlesource.com/3696
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This is a followup to CL 3676.
Rather than silently returning from the test, a pass,
use the Skip facility to mark the test as skipped.
Change-Id: I90d237e770150bf8d69f14fb09874e70894a7f86
Reviewed-on: https://go-review.googlesource.com/3682
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
On some systems (e.g. ChromeOS), / is mounted read-only.
This results in error code syscall.EROFS, which I guess
is just as valid as syscall.EACCES for this test.
Change-Id: I9188d5437a1b5ac1daa9c68b95b8dcb447666ca3
Reviewed-on: https://go-review.googlesource.com/3676
Reviewed-by: Ian Lance Taylor <iant@golang.org>
No other functional changes.
Change-Id: I7e0bb7452c6a265535297ec7ce6a629f1aff695c
Reviewed-on: https://go-review.googlesource.com/3674
Reviewed-by: Alan Donovan <adonovan@google.com>
No other functional changes.
Change-Id: I8be1fc488caa4f3d4c00afcb8c00475bfcd10709
Reviewed-on: https://go-review.googlesource.com/3673
Reviewed-by: Alan Donovan <adonovan@google.com>
No other functional changes.
Change-Id: If0d9e6208d53478e70d991b6926ea196b2cccf2e
Reviewed-on: https://go-review.googlesource.com/3672
Reviewed-by: Alan Donovan <adonovan@google.com>
These are no longer used by anything.
Change-Id: I50c971418b07cafc983242833a196ba2028a2723
Reviewed-on: https://go-review.googlesource.com/3603
Reviewed-by: Rob Pike <r@golang.org>
Another attempt to fix the arm build by moving the include of signal.h
to cmd/lex.c, unless we are building on plan9.
Obviously if we had a plan9/arm builder this would probably not work, but
this is only a temporary measure until the c2go transition is complete.
Change-Id: I7f8ae27349b2e7a09c55db03e02a01939159a268
Reviewed-on: https://go-review.googlesource.com/3566
Reviewed-by: Russ Cox <rsc@golang.org>
The following line in sysFree:
n += (n + memRound) &^ memRound
doubles value of n (n += n).
Which is wrong and can lead to memory corruption.
Fixes#9712
Change-Id: I3c141b71da11e38837c09408cf4f1d22e8f7f36e
Reviewed-on: https://go-review.googlesource.com/3602
Reviewed-by: David du Colombier <0intro@gmail.com>
REG_R0 etc are defined in <ucontext.h> on ARM systems.
Possible use of uninitialized n in 8g/reg.c.
Change-Id: I6e8ce83a6515ca2b779ed8a344a25432db629cc2
Reviewed-on: https://go-review.googlesource.com/3578
Reviewed-by: Russ Cox <rsc@golang.org>
There are no D_ names anymore.
Change-Id: Id3f1ce5efafb93818e5fd16c47ff48bbf61b5339
Reviewed-on: https://go-review.googlesource.com/3520
Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>
headstr(Hlinux) was reporting "android",
making for some confusing error messages.
Change-Id: I437095bee7cb2143aa37c91cf786f3a3581ae7b9
Reviewed-on: https://go-review.googlesource.com/3513
Reviewed-by: Austin Clements <austin@google.com>
In addition to duplicating the logic, the old code was
clearing the line number, which led to missing source line
information in the -S output.
Also fix nopout, which was incomplete.
Change-Id: Ic2b596a2f9ec2fe85642ebe125cca8ef38c83085
Reviewed-on: https://go-review.googlesource.com/3512
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Dave Cheney <dave@cheney.net>
- certain code paths were appending to the string without first clearing it.
- some prints were using spaces instead of tabs
Change-Id: I7a3d38289c8206682baf8942abf5a9950a56b449
Reviewed-on: https://go-review.googlesource.com/3511
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Dave Cheney <dave@cheney.net>
cmd/go doesn't complain (this is an open issue), but go/types does
Change-Id: I2caec1f7aec991a9500d2c3504c29e4ab718c138
Reviewed-on: https://go-review.googlesource.com/3541
Reviewed-by: Alan Donovan <adonovan@google.com>
Set gcscanvalid=false after you have cased to _Grunning.
If you do it before the cas and the atomicstatus races to a scan state,
the scan will set gcscanvalid=true and we will be _Grunning
with gcscanvalid==true which is not a good thing.
Change-Id: Ie53ea744a5600392b47da91159d985fe6fe75961
Reviewed-on: https://go-review.googlesource.com/3510
Reviewed-by: Austin Clements <austin@google.com>
Yet another leftover from C: parfor took a func value for the
callback, casted it to an unsafe.Pointer for storage, and then casted
it back to a func value to call it. This is unnecessary, so just
store the body as a func value. Beyond general cleanup, this also
eliminates the last use of unsafe in parfor.
Change-Id: Ia904af7c6c443ba75e2699835aee8e9a39b26dd8
Reviewed-on: https://go-review.googlesource.com/3396
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Prior to the conversion of the runtime to Go, this void* was
necessary to get closure information in to C callbacks. There
are no more C callbacks and parfor is perfectly capable of
invoking a Go closure now, so eliminate ctx and all of its
unsafe-ness. (Plus, the runtime currently doesn't use ctx for
anything.)
Change-Id: I39fc53b7dd3d7f660710abc76b0d831bfc6296d8
Reviewed-on: https://go-review.googlesource.com/3395
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
parfor originally used a tail array for its thread array. This got
replaced with a slice allocation in the conversion to Go, but many of
its gnarlier effects remained. Instead of keeping track of the
pointer to the first element of the slice and using unsafe pointer
math to get at the ith element, just keep the slice around and use
regular slice indexing. There is no longer any need for padding to
64-bit align the tail array (there hasn't been since the Go
conversion), so remove this unnecessary padding from the parfor
struct. Finally, since the slice tracks its own length, replace the
nthrmax field with len(thr).
Change-Id: I0020a1815849bca53e3613a8fa46ae4fbae67576
Reviewed-on: https://go-review.googlesource.com/3394
Reviewed-by: Russ Cox <rsc@golang.org>
This cleanup was slated for after the conversion of the runtime to Go.
Also improve type and function documentation.
Change-Id: I55a16b09e00cf701f246deb69e7ce7e3e04b26e7
Reviewed-on: https://go-review.googlesource.com/3393
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Currently, if we do an atomic{load,store}64 of an unaligned address on
386, we'll simply get a non-atomic load/store. This has been the
source of myriad bugs, so add alignment checks to these two
operations. These checks parallel the equivalent checks in
sync/atomic.
The alignment check is not necessary in cas64 because it uses a locked
instruction. The CPU will either execute this atomically or raise an
alignment fault (#AC)---depending on the alignment check flag---either
of which is fine.
This also fixes the two places in the runtime that trip the new
checks. One is in the runtime self-test and shouldn't have caused
real problems. The other is in tickspersecond and could, in
principle, have caused a misread of the ticks per second during
initialization.
Change-Id: If1796667012a6154f64f5e71d043c7f5fb3dd050
Reviewed-on: https://go-review.googlesource.com/3521
Reviewed-by: Russ Cox <rsc@golang.org>
