The tiny alloc cache is maintained in a pointer from non-GC'd memory
(mcache) to heap memory and hence must be handled carefully.
Currently we clear the tiny alloc cache during sweep termination and,
if it is assigned to a non-nil value during concurrent marking, we
depend on a write barrier to keep the new value alive. However, while
the compiler currently always generates this write barrier, we're
treading on thin ice because write barriers may not happen for writes
to non-heap memory (e.g., typedmemmove). Without this lucky write
barrier, the GC may free a current tiny block while it's still
reachable by the tiny allocator, leading to later memory corruption.
Change this code so that, rather than depending on the write barrier,
we simply clear the tiny cache during mark termination when we're
clearing all of the other mcaches. If the current tiny block is
reachable from regular pointers, it will be retained; if it isn't
reachable from regular pointers, it may be freed, but that's okay
because there won't be any pointers in non-GC'd memory to it.
Change-Id: I8230980d8612c35c2997b9705641a1f9f865f879
Reviewed-on: https://go-review.googlesource.com/16962
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The user can inspect the record data to detect that the other side is
not using the TLS protocol.
This will be used by the net/http client (in a follow-on CL) to detect
when an HTTPS client is speaking to an HTTP server.
Updates #11111.
Change-Id: I872f78717aa8e8e98cebd8075436209a52039a73
Reviewed-on: https://go-review.googlesource.com/16078
Reviewed-by: Adam Langley <agl@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The change to the write barrier in https://golang.org/cl/16899 means
that the compiler now emits tests of the first field of a struct. That
was using a register that was not used before. This change fixes that
for amd64 by adding a special case for the first field of a struct.
Update #12416.
Change-Id: Ia57baa62cd741592fbeb9be82f1e846be73d6edd
Reviewed-on: https://go-review.googlesource.com/16933
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
If you set GODEBUG=cgocheck=2 the runtime package will use the write
barrier to detect cases where a Go program writes a Go pointer into
non-Go memory. In conjunction with the existing cgo checks, and the
not-yet-implemented cgo check for exported functions, this should
reliably detect all cases (that do not import the unsafe package) in
which a Go pointer is incorrectly shared with C code. This check is
optional because it turns on the write barrier at all times, which is
known to be expensive.
Update #12416.
Change-Id: I549d8b2956daa76eac853928e9280e615d6365f4
Reviewed-on: https://go-review.googlesource.com/16899
Reviewed-by: Russ Cox <rsc@golang.org>
The current mkdeps.bash just checks for dependencies for GOOS=windows
with the current GOARCH. This is not always accurate as some package
imports only happen on specific GOOS/GOARCH combinations. Check a
selected, easily changed, combination of GOOS/GOARCH values.
This generates a deps.go identical to the one in the repository today.
Fixes#13221.
Change-Id: I96d67d49c8c63641d578acedbb28be807607db65
Reviewed-on: https://go-review.googlesource.com/16882
Reviewed-by: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Just like android/arm, android/arm64 refuses to execute non-PIE
binaries. In addition, starting from the M release (Marshmallow),
Android refuses to execute binaries with any text relocations
(this was just a warning in the L release). This makes "-shared"
necessary as well when building executables for Android.
Change-Id: Id8802de5be98ff472fc370f8d22ffbde316aaf1e
Reviewed-on: https://go-review.googlesource.com/16744
Reviewed-by: Ian Lance Taylor <iant@golang.org>
In mheap.sysAlloc, if an allocation at arena_used would exceed
arena_end (but wouldn't yet push us past arena_start+_MaxArean32), it
trie to extend the arena reservation by another 256 MB. It extends the
arena by calling sysReserve, which, on 32-bit, calls mmap without
MAP_FIXED, which means the address is just a hint and the kernel can
put the mapping wherever it wants. In particular, mmap may choose an
address below arena_start (the kernel also chose arena_start, so there
could be lots of space below it). Currently, we don't detect this case
and, if it happens, mheap.sysAlloc will corrupt arena_end and
arena_used then return the low pointer to mheap.grow, which will crash
when it attempts to index in to h_spans with an underflowed index.
Fix this by checking not only that that p+p_size isn't too high, but
that p isn't too low.
Fixes#13143.
Change-Id: I8d0f42bd1484460282a83c6f1a6f8f0df7fb2048
Reviewed-on: https://go-review.googlesource.com/16927
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
If the area returned by sysReserve in mheap.sysAlloc is outside the
usable arena, we sysFree it. We pass a fake stat pointer to sysFree
because we haven't added the allocation to any stat at that point.
However, we pass a 0 stat, so sysFree panics when it decrements the
stat because the fake stat underflows.
Fix this by setting the fake stat to the allocation size.
Updates #13143 (this is a prerequisite to fixing that bug).
Change-Id: I61a6c9be19ac1c95863cf6a8435e19790c8bfc9a
Reviewed-on: https://go-review.googlesource.com/16926
Reviewed-by: Ian Lance Taylor <iant@golang.org>
And enable PIE in the go tool.
Change-Id: Ibb60ccfe62518cde6e33080bbc78bfcbecff6a4e
Reviewed-on: https://go-review.googlesource.com/14000
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
golang.org/cl/16346 changed the runtime on linux/386 to invoke the vsyscall
helper via a PIC sequence (CALL 0x10(GS)) when dynamically linking. But it's
actually quite easy to make that code sequence work all the time, so do that,
and remove the ugly machinery that passed the buildmode from the go tool to the
assembly.
This means enlarging m.tls so that we can safely access 0x10(GS) (GS is set to
&m.tls + 4, so 0x10(GS) accesses m_tls[5]).
Change-Id: I1345c34029b149cb5f25320bf19a3cdd73a056fa
Reviewed-on: https://go-review.googlesource.com/16796
Reviewed-by: Ian Lance Taylor <iant@golang.org>
A nosplit comment was added to reflect.typelinks accidentally in
https://golang.org/cl/98510044. There is only one caller of
reflect.typelinks, reflect.typesByString, and that function is not
nosplit. There is no reason for reflect.typelinks to be nosplit.
Change-Id: I0fd3cc66fafcd92643e38e53fa586d6b2f868a0a
Reviewed-on: https://go-review.googlesource.com/16932
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
This allows slices of custom types with byte as underlying type to be
decoded, fixing a regression introduced in CL 9371.
Fixes#12921.
Change-Id: I62a715eaeaaa912b6bc599e94f9981a9ba5cb242
Reviewed-on: https://go-review.googlesource.com/16303
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Following a recent change, file builtin.go is not up-to-date.
Generate it again by running go generate.
Fixes#13203
Change-Id: Ib91c5ccc93665c043da95c7d3783ce5d94e48466
Reviewed-on: https://go-review.googlesource.com/16821
Reviewed-by: Ian Lance Taylor <iant@golang.org>
It is too slow with kernel FPU emulator.
Updates #12688.
Change-Id: Ib3a5adfeb46e894550231b14eb0f4fb20aecee11
Reviewed-on: https://go-review.googlesource.com/16922
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Change the linker to use a copy of the C compiler support library,
libgcc.a, when doing internal linking. This will be used to satisfy any
undefined symbols referenced by host objects.
Change the dist tool to copy the support library into a new directory
tree under GOROOT/pkg/libgcc. This ensures that libgcc is available
even when building Go programs on a system that has no C compiler. The
C compiler is required when building the Go installation in the first
place, but is not required thereafter.
Change the go tool to not link libgcc into cgo objects.
Correct the linker handling of a weak symbol in an ELF input object to
not always create a new symbol, but to use an existing symbol if there
is one; this is necessary on freebsd-amd64, where libgcc contains a weak
definition of compilerrt_abort_impl.
Fixes#9510.
Change-Id: I1ab28182263238d9bcaf6a42804e5da2a87d8778
Reviewed-on: https://go-review.googlesource.com/16741
Reviewed-by: Russ Cox <rsc@golang.org>
Inlined non_dcl_stmt in stmt since it was called only from there.
Change-Id: I616c41332cfd86bbf3493d0ce7b1256384215220
Reviewed-on: https://go-review.googlesource.com/16893
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Chris Manghane <cmang@golang.org>
- better error messages
- better error recovery by advancing to "follow" token after error
- make sure that we make progress after all errors
- minor cleanups
Change-Id: Ie43b8b02799618d70dc8fc227fab3e4e9e0d8e3a
Reviewed-on: https://go-review.googlesource.com/16892
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Chris Manghane <cmang@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
These now live in runtime/internal/sys.
Change-Id: I270597142516512bfc1395419e51d8083ba1663f
Reviewed-on: https://go-review.googlesource.com/16891
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Exported methods of unexported embedded structs get added
correctly to the pool. Behavior is unchanged before and after
https://golang.org/cl/14085.
Change-Id: I2b4053bab02ff045f0a4577b8114808a60aae27e
Reviewed-on: https://go-review.googlesource.com/16305
Reviewed-by: Russ Cox <rsc@golang.org>
Steve Newman (Google CLA) was missing from the CONTRIBUTORS file,
presumably because his old commits (made prior to Go being open
source) in SVN/perforce were imported into hg/git later as
"devnull@localhost", which probably didn't match anything, and we
didn't start tracking CLA contributions prior to the Go
open source release.
As a fun historical note, the initial HTTP client from Steve:
https://github.com/golang/go/commit/f315fb3
Change-Id: I2b8da4564d99820504788ecc41495a62391078d5
Reviewed-on: https://go-review.googlesource.com/16864
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This is a translation of the yacc-based parser with adjustements
to make the grammar work for a recursive-descent parser followed
by cleanups and simplifications.
The yacc actions were mostly literally copied for correctness
with better temporary names.
A few of the syntax tests were adjusted for slightly different
error messages (it is very difficult to match the yacc-based
error messages in all cases, and sometimes the new parser could
produce better errors).
The new parser is enabled by default.
To switch back to the yacc-based parser, set -oldparser.
To hardwire the switch back, uncomment "oldparser = 1" in lex.go.
- passes all.bash
- ~18% reduced parse time per file on average for make.bash
- ~3% reduced compile time for building cmd/compile
Change-Id: Icb5651bb9d8b9f66261762d2c94a03793050d4ce
Reviewed-on: https://go-review.googlesource.com/16665
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Fix the output of build -n when adding to an existing archive with the
gc toolchain by observing that we are, now, always doing that. When
using the gc toolchain the archive is now always created by the Go
compiler, and never by the pack command.
No test because we have not historically tested build -n output.
Fixes#13118.
Change-Id: I3a5c43cf45169fa6c9581e4741309c77d2b6e58b
Reviewed-on: https://go-review.googlesource.com/16761
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
The gzip package is asymmetrical in the way it handles headers.
In Writer, the Header is written on the first call to Write, Flush, or Close.
In Reader, the Header is read on calls to NewReader or Reset as opposed to
after the first Read. Thus, we document this difference.
Fixes#13211
Change-Id: I5f87beff036e5e2fd68a02a15fdb7137e9ca4c37
Reviewed-on: https://go-review.googlesource.com/16838
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Allows removing fields that aren't relevant to a particular OS or
changing their types to match the underlying OS system calls they'll
be used for.
Change-Id: I5cea89ee77b4e7b985bff41337e561887c3272ff
Reviewed-on: https://go-review.googlesource.com/16176
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
so that GO_TEST_TIMEOUT_SCALE can be applied too.
It's for the mips64 builder, which is so slow that the
go1 benchmark can't finish startup within 10 minutes.
Change-Id: I1b824eb0649460101b294fb442da784e872403e7
Reviewed-on: https://go-review.googlesource.com/16901
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Replaces PID in PaxHeaders with 0. Sorts PAX header keys before writing
them to the archive.
Fixes#12358
Change-Id: If239f89c85f1c9d9895a253fb06a47ad44960124
Reviewed-on: https://go-review.googlesource.com/13975
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Joe Tsai <joetsai@digital-static.net>
We're allocating TLS storage for m0 anyway, so might as well use it.
Change-Id: I7dc20bbea5320c8ab8a367f18a9540706751e771
Reviewed-on: https://go-review.googlesource.com/16890
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
