CL 544455, which added atomic And/Or APIs, raced with CL 585556, which
enabled stricter linkname checking. This caused linkname-related
failures on ARM and MIPS. Fix this by adding the necessary linknames.
We fix one other linkname that got overlooked in CL 585556.
Updates #61395.
Change-Id: I454f0767ce28188e550a61bc39b7e398239bc10e
Reviewed-on: https://go-review.googlesource.com/c/go/+/586516
Reviewed-by: Mauri de Souza Meneguzzo <mauri870@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Austin Clements <austin@google.com>
This change fixes problems with thread-locked goroutines using
newcoro/coroswitch/etc. Currently, the coro paths do not consider
thread-locked goroutines at all and can quickly result in broken
scheduler state or lost/leaked goroutines.
One possible fix to these issues is to fall back on goroutine+channel
semantics, but that turns out to be fairly complicated to implement and
results in significant performance cliffs. More complex thread-lock
state donation tricks also result in some fairly complicated state
tracking that doesn't seem worth it given the use-cases of iter.Pull
(and even then, there will be performance cliffs).
This change implements a much simpler, but more restrictive semantics.
In particular, thread-lock state is tied to the coro at the first call
to newcoro (i.e. iter.Pull). From then on, the invariant is that if the
coro has any thread-lock state *or* a goroutine calling into coroswitch
has any thread-lock state, that the full gamut of thread-lock state must
remain the same as it was when newcoro was called (the full gamut
meaning internal and external lock counts as well as the identity of the
thread that was locked to).
This semantics allows the common cases to be always fast, but comes with
a non-orthogonality caveat. Specifically, when iter.Pull is used in
conjunction with thread-locked goroutines, complex cases (passing next
between goroutines or passing yield between goroutines) are likely to
fail. Simple cases, where any number of iter.Pull iterators are used in
a straightforward way (nested, in series, etc.) from the same
goroutine, will work and will be guaranteed to be fast regardless of
thread-lock state.
This is a compromise for the near-term and we may consider lifting the
restrictions imposed by this CL in the future.
Fixes#65889.
Fixes#65946.
Change-Id: I3fb5791e36a61f5ded50226a229a79d28739b24e
Reviewed-on: https://go-review.googlesource.com/c/go/+/583675
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Austin Clements <austin@google.com>
This change moves the v2 tracer into the trace directory.
Updates #67367
Change-Id: I3657b4227002cb00fdf29c797434800ea796715e
Reviewed-on: https://go-review.googlesource.com/c/go/+/584538
Reviewed-by: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
This CL implements the new sync/atomic AND and OR apis as well as their race
counterparts.
Fixes#61395
Change-Id: I294eefe4b3ac27bc4ed237edcbfa88a8c646d86f
GitHub-Last-Rev: f174297007
GitHub-Pull-Request: golang/go#64331
Reviewed-on: https://go-review.googlesource.com/c/go/+/544455
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Auto-Submit: Austin Clements <austin@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
This change removes unused parts of the v1 tracer in preperation of
the move of the v2 tracer into the trace package.
Updates #67367
Change-Id: I3e53a8afdef72dc90c2d5b514380d1077d284bc7
Reviewed-on: https://go-review.googlesource.com/c/go/+/584537
Reviewed-by: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
CL 585358 adds restrictions to disallow pull-only linknames
(currently off by default). Currently, there are quite some pull-
only linknames in user code in the wild. In order not to break
those, we add push linknames to allow them to be pulled. This CL
includes linknames found in a large code corpus (thanks Matthew
Dempsky and Michael Pratt for the analysis!), that are not
currently linknamed.
Updates #67401.
Change-Id: I32f5fc0c7a6abbd7a11359a025cfa2bf458fe767
Reviewed-on: https://go-review.googlesource.com/c/go/+/586137
Reviewed-by: Russ Cox <rsc@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
This patch removes redundant guards for the crash stack feature, as all
supported Go architectures now have a crash stack implementation.
Change-Id: I7ffb61c57955778d687073418130b2aaab0ff183
GitHub-Last-Rev: 6ff56d6420
GitHub-Pull-Request: golang/go#67202
Reviewed-on: https://go-review.googlesource.com/c/go/+/583416
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Run-TryBot: Mauri de Souza Meneguzzo <mauri870@gmail.com>
callbackUpdateSystemStack contains a fast path to exit early without
update if SP is already within the g0.stack bounds.
This is not safe, as a subsequent call may have new stack bounds that
only partially overlap the old stack bounds. In this case it is possible
to see an SP that is in the old stack bounds, but very close to the
bottom of the bounds due to the partial overlap. In that case we're very
likely to "run out" of space on the system stack.
We only need to do this on extra Ms, as normal Ms have precise bounds
defined when we allocated the stack.
TSAN annotations are added to x_cgo_getstackbounds because bounds is a
pointer into the Go stack. The stack can be reused when an old thread
exits and a new thread starts, but TSAN can't see the synchronization
there. This isn't a new case, but we are now calling more often.
Fixes#62440.
Cq-Include-Trybots: luci.golang.try:gotip-linux-amd64-longtest
Change-Id: I5389050494987b7668d0b317fb92f85e61d798ac
Reviewed-on: https://go-review.googlesource.com/c/go/+/584597
Reviewed-by: Cherry Mui <cherryyz@google.com>
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This is a placeholder for future options (e.g. JSON).
The parameter is temporarily variadic to avoid breaking
x/telemetry (see CL 585378), but I plan to remove
the "..." later this week.
Updates #67182
Change-Id: I3f6f39455d852f92902f8e3f007d3093cbe555db
Reviewed-on: https://go-review.googlesource.com/c/go/+/585557
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Austin Clements <austin@google.com>
As mentioned in CL 584598, linkname is a mechanism that, when
abused, can break API integrity and even safety of Go programs.
CL 584598 is a first step to restrict the use of linknames, by
implementing a blocklist. This CL takes a step further, tightening
up the restriction by allowing linkname references ("pull") only
when the definition side explicitly opts into it, by having a
linkname on the definition (possibly to itself). This way, it is at
least clear on the definition side that the symbol, despite being
unexported, is accessed outside of the package. Unexported symbols
without linkname can now be actually private. This is similar to
the symbol visibility rule used by gccgo for years (which defines
unexported non-linknamed symbols as C static symbols).
As there can be pull-only linknames in the wild that may be broken
by this change, we currently only enforce this rule for symbols
defined in the standard library. Push linknames are added in the
standard library to allow things build.
Linkname references to external (non-Go) symbols are still allowed,
as their visibility is controlled by the C symbol visibility rules
and enforced by the C (static or dynamic) linker.
Assembly symbols are treated similar to linknamed symbols.
This is controlled by -checklinkname linker flag, currently not
enabled by default. A follow-up CL will enable it by default.
Change-Id: I07344f5c7a02124dbbef0fbc8fec3b666a4b2b0e
Reviewed-on: https://go-review.googlesource.com/c/go/+/585358
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
CL 581215 changed 'throw' so that instead of print(s) it called
a more complicated function, printpanicval, that statically
appeared to have convTstring in its call graph, even though this
isn't dynamically reachable when called with a string argument.
However, this caused the link-time static callgraph test to point
out that throw (which is called in nowritebarrierrec contexts
such as markgc) reaches a write barrier.
The solution is to inline and specialize the printpanicval
function for strings; it reduces to printindented.
Thanks to mpratt for pointing out that the reachability
check is on the fully lowered code, and is thus sensitive
to optimizations such as inlining.
I added an explanatory comment on the line that generates
the error message to help future users confused as I was.
Fixesgolang/go#67274
Change-Id: Ief110d554de365ce4c09509dceee000cbee30ad9
Reviewed-on: https://go-review.googlesource.com/c/go/+/584617
Reviewed-by: Than McIntosh <thanm@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Use frame pointer unwinding, where supported, to collect call stacks for
the block, and mutex profilers. This method of collecting call stacks is
typically an order of magnitude faster than callers/tracebackPCs. The
marginal benefit for these profile types is likely small compared to
using frame pointer unwinding for the execution tracer. However, the
block profiler can have noticeable overhead unless the sampling rate is
very high. Additionally, using frame pointer unwinding in more places
helps ensure more testing/support, which benefits systems like the
execution tracer which rely on frame pointer unwinding to be practical
to use.
Change-Id: I4b36c90cd2df844645fd275a41b247352d635727
Reviewed-on: https://go-review.googlesource.com/c/go/+/533258
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Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Cherry Mui <cherryyz@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
fpunwindExpand currently allocates a new slice to hold the expanded call
stack. In each place it's used, the resulting slice won't be needed
immediately afterward, so the allocation is wasteful. Refactor
fpunwindExpand to instead expand the call stack into a provided buffer.
Change-Id: I05b26c191a8f76404c21ccbe3bd422325540425b
Reviewed-on: https://go-review.googlesource.com/c/go/+/543715
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Cherry Mui <cherryyz@google.com>
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Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Adds runtime.debugPinnerV1 which returns a runtime.Pinner object that
pins itself. This is intended to be used by debuggers in conjunction
with runtime.debugCall to keep heap memory reachable even if it isn't
referenced from anywhere else.
Change-Id: I508ee6a7b103e68df83c96f2e04a0599200300dc
Reviewed-on: https://go-review.googlesource.com/c/go/+/558276
Reviewed-by: Cherry Mui <cherryyz@google.com>
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Reviewed-by: Austin Clements <austin@google.com>
Running with few threads usually does not need 500ms to crash, so let it
crash as soon as possible. While the test may caused more time on slow
machine, try to expand the sleep time in test.
Updates #64752
Change-Id: I635fab846bd5e1735808d4d47bb9032d5a04cc2b
GitHub-Last-Rev: 84f3844ac0
GitHub-Pull-Request: golang/go#65018
Reviewed-on: https://go-review.googlesource.com/c/go/+/554615
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Auto-Submit: Cherry Mui <cherryyz@google.com>
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Reviewed-by: Cherry Mui <cherryyz@google.com>
Temporarily mark the function runtime.throw as "go:noinline" for the
time being to work around problems introduced by CL 581215. We do not
ordinarily inline runtime.throw unless the build is beind done with an
elevated inline budget (e.g. "-gcflags=-l=4"), so this change should
only have an effect for those special builds.
Updates #67274.
Change-Id: I3811913b8d441e0ddb1d4c7d7297ef23555582a2
Reviewed-on: https://go-review.googlesource.com/c/go/+/584616
Reviewed-by: Alan Donovan <adonovan@google.com>
Auto-Submit: Than McIntosh <thanm@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Mauri de Souza Meneguzzo <mauri870@gmail.com>
This CL causes the printing of panic values to ensure that all
newlines in the output are immediately followed by a tab, so
that there is no way for a maliciously crafted panic value to
fool a program attempting to parse the traceback into thinking
that the panic value is in fact a goroutine stack.
See https://github.com/golang/go/issues/64590#issuecomment-1932675696
+ release note
Updates #64590
Updates #63455
Change-Id: I5142acb777383c0c122779d984e73879567dc627
Reviewed-on: https://go-review.googlesource.com/c/go/+/581215
Auto-Submit: Alan Donovan <adonovan@google.com>
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Reviewed-by: Michael Pratt <mpratt@google.com>
Currently freeSpan is called before large object stats are updated when
sweeping large objects. This means heapStats.inHeap might get subtracted
before the large object is added to the largeFree field. The end result
is that the /memory/classes/heap/unused:bytes metric, which subtracts
live objects (alloc-free) from inHeap may overflow.
Fix this by always updating the large object stats before calling
freeSpan.
Fixes#67019.
Change-Id: Ib02bd8dcd1cf8cd1bc0110b6141e74f678c10445
Reviewed-on: https://go-review.googlesource.com/c/go/+/583380
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Felix Geisendörfer <felix.geisendoerfer@datadoghq.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
The page tracer's functionality is now captured by the regular execution
tracer as an experimental GODEBUG variable. This is a lot more usable
and maintainable than the page tracer, which is likely to have bitrotted
by this point. There's also no tooling available for the page tracer.
Change-Id: I2408394555e01dde75a522e9a489b7e55cf12c8e
Reviewed-on: https://go-review.googlesource.com/c/go/+/583379
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Move profiling pc buffers from being stack allocated to an m field.
This is motivated by the next patch, which will increase the default
stack depth to 128, which might lead to undesirable stack growth for
goroutines that produce profiling events.
Additionally, this change paves the way to make the stack depth
configurable via GODEBUG.
Change-Id: Ifa407f899188e2c7c0a81de92194fdb627cb4b36
Reviewed-on: https://go-review.googlesource.com/c/go/+/574699
Reviewed-by: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
This change adds expensive alloc/free events to traces, guarded by a
GODEBUG that can be set at run time by mutating the GODEBUG environment
variable. This supersedes the alloc/free trace deleted in a previous CL.
There are two parts to this CL.
The first part is adding a mechanism for exposing experimental events
through the tracer and trace parser. This boils down to a new
ExperimentalEvent event type in the parser API which simply reveals the
raw event data for the event. Each experimental event can also be
associated with "experimental data" which is associated with a
particular generation. This experimental data is just exposed as a bag
of bytes that supplements the experimental events.
In the runtime, this CL organizes experimental events by experiment.
An experiment is defined by a set of experimental events and a single
special batch type. Batches of this special type are exposed through the
parser's API as the aforementioned "experimental data".
The second part of this CL is defining the AllocFree experiment, which
defines 9 new experimental events covering heap object alloc/frees, span
alloc/frees, and goroutine stack alloc/frees. It also generates special
batches that contain a type table: a mapping of IDs to type information.
Change-Id: I965c00e3dcfdf5570f365ff89d0f70d8aeca219c
Reviewed-on: https://go-review.googlesource.com/c/go/+/583377
Reviewed-by: Michael Pratt <mpratt@google.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
allocfreetrace prints all allocations and frees to stderr. It's not
terribly useful because it has a really huge overhead, making it not
feasible to use except for the most trivial programs. A follow-up CL
will replace it with something that is both more thorough and also lower
overhead.
Change-Id: I1d668fee8b6aaef5251a5aea3054ec2444d75eb6
Reviewed-on: https://go-review.googlesource.com/c/go/+/583376
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Reviewed-by: Carlos Amedee <carlos@golang.org>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
If a signal lands on a non-Go thread, and Go code doesn't want to
handle it, currently we re-raise the signal in the signal handler
after uninstalling our handler, so the C code can handle it.
But if there is no C signal handler and the signal is ignored,
there is no need to re-raise the signal. Just ignore it. This
avoids uninstalling and reinstalling our handler, which, for some
reason, changes errno when TSAN is used. And TSAN does not like
errno being changed in the signal handler.
Not really sure if this is the bset of complete fix, but it does
fix the immediate problem, and it seems a reasonable thing to do
by itself.
Test case is CL 581722.
Fixes#66427.
Change-Id: I7a043d53059f1ff4080f4fc8ef4065d76ee7d78a
Reviewed-on: https://go-review.googlesource.com/c/go/+/582077
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
This code was just missed during the cleanup. There's maybe some merit
to keeping OneNewExtraM, but it would still be fairly optimistic. It's
trivial to bring back, so delete it for now.
Change-Id: I2d033c6daae787e0e8d6b92524f3e59610e2599f
Reviewed-on: https://go-review.googlesource.com/c/go/+/583375
Reviewed-by: Carlos Amedee <carlos@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
This CL reduces
the go test runtime time from 130s to 59s.
Change-Id: I91babcd15723a2e7bc706e4e9bddaf3ce39d5b2f
GitHub-Last-Rev: 54c3c82269
GitHub-Pull-Request: golang/go#65765
Cq-Include-Trybots: luci.golang.try:gotip-linux-386-longtest
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Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Goids are designed to be big enough that they will never be reused:
a uint64 is enough to generate a new goroutine every nanosecond
for 500+ years before wrapping around, and after 500 years you
should probably stop and pick up some security updates.
This note was added in CL 70993 and appears to have just been
a misunderstanding by the CL author.
Change-Id: Ida7099b5191a4e5dbb1e3e9e44b4b86d7779fd6d
Reviewed-on: https://go-review.googlesource.com/c/go/+/582895
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Reviewed-by: Michael Pratt <mpratt@google.com>
Auto-Submit: Russ Cox <rsc@golang.org>
Windows time.Now granularity is around 0.5ms on modern systems,
which introduces a significant noise into benchmark results.
Instead of relying time.Now use QueryPerformanceCounter, which
has significantly better granularity compared to time.Now.
│ TimeNow-32 │ HighPrecisionTimeNow-32 │
│ sec/op │ sec/op vs base │
4.812n ± 0% 30.580n ± 0% +535.43% (p=0.000 n=20)
Fixes#31160
Change-Id: Ib2a574d638c9c6762a2524212def02265574e267
Reviewed-on: https://go-review.googlesource.com/c/go/+/557315
Reviewed-by: Quim Muntal <quimmuntal@gmail.com>
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Reviewed-by: Michael Knyszek <mknyszek@google.com>
The Windows native stack unwinder incorrectly classifies the next
instruction after the mcall callback call as being part of the function
epilogue, producing a wrong call stack.
Add a NOP after the callback call to work around this issue.
Fixes#67007.
Change-Id: I6017635da895b272b1852391db9a255ca69e335d
Reviewed-on: https://go-review.googlesource.com/c/go/+/581335
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Fully testing the runtime's profiles and metrics for contention on its
internal mutex values involves comparing two separate clocks (cputicks
for the profile and nanotime for the metric), verifying its fractional
sampling (when MutexProfileRate is greater than 1), and observing a very
small critical section outside of the test's control (semrelease).
Flakiness (#64253) from those parts of the test have led to skipping it
entirely.
But there are portions of the mutex profiling behavior that should have
more consistent behavior: for a mutex under the test's control, the test
and the runtime should be able to agree that the test successfully
induced contention, and should agree on the call stack that caused the
contention. Allow those more consistent parts to run.
For #64253
Change-Id: I7f368d3265a5c003da2765164276fab616eb9959
Reviewed-on: https://go-review.googlesource.com/c/go/+/581296
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Reviewed-by: Joedian Reid <joedian@google.com>
Auto-Submit: Rhys Hiltner <rhys.hiltner@gmail.com>
CL 580255 increased the frame size of entersyscall and reentersyscall,
which is causing the x/sys repository to fail to build for
windows/arm64 because of an overflow of the nosplit stack reservation.
Fix this by wrapping the other call to throw in casgstatus in a system
stack switch. This is a fatal throw anyway indicating a core runtime
invariant is broken, so this path is basically never taken. This cuts
off the nosplit frame chain and allows x/sys to build.
Change-Id: I00b16c9db3a7467413ed48953c7f8a9a750f000a
Reviewed-on: https://go-review.googlesource.com/c/go/+/580775
Reviewed-by: Cherry Mui <cherryyz@google.com>
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Define it as ABIInternal, so the result does not take space on
stack.
Also use R10 as a temporary register for arithmetics on SP, so it
is hidden from the assembler's SP delta calculation, which is
irrelevant anyway as we are on the system stack.
Change-Id: I8fed467601c19cad2d7afab26978246d15ce3147
Reviewed-on: https://go-review.googlesource.com/c/go/+/580918
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TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Cherry Mui <cherryyz@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
During my research of pahole with Go structs, I've found couple of
structs in runtime/ pkg where we can reduce several structs' sizes
highligted by pahole tool which detect byte holes and paddings.
Overall, there are 80 bytes reduced.
Change-Id: I398e5ed6f5b199394307741981cb5ad5b875e98f
Reviewed-on: https://go-review.googlesource.com/c/go/+/578795
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Joedian Reid <joedian@google.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
This was an oversight and is causing a few failures, most notably on
Solaris and Illumos, but also occasionally on the Linux builders.
Change-Id: I38bd28537ad01d955675f61f9b1d42b9ecdd1ef0
Reviewed-on: https://go-review.googlesource.com/c/go/+/580875
Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
It isn't specific to maps, so put it in a more general location.
For #54766.
Change-Id: Ia3f3ebe8c347cfa5a8582082a306f4df4e05818d
Reviewed-on: https://go-review.googlesource.com/c/go/+/580777
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
This change adds the unique package for canonicalizing values, as
described by the proposal in #62483.
Fixes#62483.
Change-Id: I1dc3d34ec12351cb4dc3838a8ea29a5368d59e99
Reviewed-on: https://go-review.googlesource.com/c/go/+/574355
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ingo Oeser <nightlyone@googlemail.com>
Reviewed-by: David Chase <drchase@google.com>
Profiling of runtime-internal locks checks gp.m.locks to see if it's
safe to add a new record to the profile, but direct use of
acquireLockRank can change the list of the M's active lock ranks without
updating gp.m.locks to match. The runtime's internal rwmutex
implementation makes a point of calling acquirem/releasem when
manipulating the lock rank list, but the other user of acquireLockRank
(the GC's Gscan bit) relied on the GC's invariants to avoid deadlocks.
Codify the rwmutex approach by renaming acquireLockRank to
acquireLockRankAndM and having it include a call to aquirem. Do the same
for release.
Fixes#64706Fixes#66004
Change-Id: Ib76eaa0cc1c45b64861d03345e17e1e843c19713
GitHub-Last-Rev: 160577bdb2
GitHub-Pull-Request: golang/go#66276
Reviewed-on: https://go-review.googlesource.com/c/go/+/571056
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Auto-Submit: Rhys Hiltner <rhys.hiltner@gmail.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
There's no need for these. If hashkey[i] is uniform over [0,1<<64), then
hashkey[0]^C has exactly the same distribution, for any constant C.
Change-Id: I4e10c27eff15e4b7a45139654ac41f410b1b12fc
Reviewed-on: https://go-review.googlesource.com/c/go/+/580218
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
We don't multiply by them any more, so no need to make them odd.
Suggested by me here in 2021:
https://go-review.googlesource.com/c/go/+/280372/comment/1a86b8aa_f64310bf/
Never got around to it until now.
Change-Id: Iddc675e6a18b4a7a785acbf77c96e127003cc3c5
Reviewed-on: https://go-review.googlesource.com/c/go/+/579116
Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Currently the first argument to mix() can be set by an attacker, as it
is just the input bytes xored by some constants. That lets an attacker
set the value being multipled by to 0. That can lead to lots of
collisions. To fix, xor the first argument with the process-wide seed,
so the magic collision-generating value isn't a constant known to the
attacker. (Maybe there's a timing attack that could figure out the
process-wide seed, but that's a much harder attack.)
Fixes#66841
Change-Id: I33e073c78355d1cee08660de52074e6ccc38b426
Reviewed-on: https://go-review.googlesource.com/c/go/+/579115
Reviewed-by: M Zhuo <mengzhuo1203@gmail.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Currently the runtime only tracks the PC and SP upon entering a syscall,
but not the FP (BP). This is mainly for historical reasons, and because
the tracer (which uses the frame pointer unwinder) does not need it.
Until it did, of course, in CL 567076, where the tracer tries to take a
stack trace of a goroutine that's in a syscall from afar. It tries to
use gp.sched.bp and lots of things go wrong. It *really* should be using
the equivalent of gp.syscallbp, which doesn't exist before this CL.
This change introduces gp.syscallbp and tracks it. It also introduces
getcallerfp which is nice for simplifying some code. Because we now have
gp.syscallbp, we can also delete the frame skip count computation in
traceLocker.GoSysCall, because it's now the same regardless of whether
frame pointer unwinding is used.
Fixes#66889.
Change-Id: Ib6d761c9566055e0a037134138cb0f81be73ecf7
Cq-Include-Trybots: luci.golang.try:gotip-linux-amd64-nocgo
Reviewed-on: https://go-review.googlesource.com/c/go/+/580255
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
The seed for rand is not initialized until after alginit. Before
initialization, rand returns a deterministic sequence, making hashkey
deterministic across processes.
Switch to bootstrapRand, like other early rand calls, such as
initialization of aeskeysched.
Fixes#66885.
Change-Id: I5023a9161232b49fda2ebd1d5f9338bbdd17b1fe
Reviewed-on: https://go-review.googlesource.com/c/go/+/580136
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
This change adds the internal/weak package, which exposes GC-supported
weak pointers to the standard library. This is for the upcoming weak
package, but may be useful for other future constructs.
For #62483.
Change-Id: I4aa8fa9400110ad5ea022a43c094051699ccab9d
Reviewed-on: https://go-review.googlesource.com/c/go/+/576297
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Austin Clements
Michael Anthony Knyszek
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Cherry Mui
Jes Cok
Alan Donovan
Michael Pratt
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qiulaidongfeng
Alessandro Arzilli
zzkcode
Than McIntosh
Felix Geisendörfer
Russ Cox
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qmuntal
Rhys Hiltner
Sabyrzhan Tasbolatov
Keith Randall