findRunnable takes a snapshot of allp prior to dropping the P because
afterwards procresize may mutate allp without synchronization.
procresize is careful to never mutate the contents up to cap(allp), so
findRunnable can still safely access the Ps in the slice.

Unfortunately, growing allp is problematic. If procresize grows the allp
backing array, it drops the reference to the old array. allpSnapshot
still refers to the old array, but allpSnapshot is on the system stack
in findRunnable, which also likely no longer has a P at all.

This means that a future GC will not find the reference and can free the
array and use it for another allocation. This would corrupt later reads
that findRunnable does from the array.

The fix is simple: the M struct itself is reachable by the GC, so we can
stash the snapshot in the M to ensure it is visible to the GC.

The ugliest part of the CL is the cleanup when we are done with the
snapshot because there are so many return/goto top sites. I am tempted
to put mp.clearAllpSnapshot() in the caller and at top to make this less
error prone, at the expensive of extra unnecessary writes.

For #74414.
For #74416.

Change-Id: I6a6a636c484e4f4b34794fd07910b3fffeca830b
Reviewed-on: https://go-review.googlesource.com/c/go/+/684460
Reviewed-by: Cherry Mui <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Auto-Submit: Michael Pratt <[email protected]>
(cherry picked from commit 740857f)
Reviewed-on: https://go-review.googlesource.com/c/go/+/685056

… objects with pointers

CL 614257 refactored mallocgc but lost an optimization: if a span for a
large object is already backed by memory fresh from the OS (and thus
zeroed), we don't need to zero it. CL 614257 unconditionally zeroed
spans for large objects that contain pointers.

This change restores the optimization from before CL 614257, which seems
to matter in some real-world programs.

While we're here, let's also fix a hole with the garbage collector being
able to observe uninitialized memory of the large object is observed
by the conservative scanner before being published. The gory details are
in a comment in heapSetTypeLarge. In short, this change makes
span.largeType an atomic variable, such that the GC can only observe
initialized memory if span.largeType != nil.

For #72991.
Fixes #73800.

Change-Id: I2048aeb220ab363d252ffda7d980b8788e9674dc
Reviewed-on: https://go-review.googlesource.com/c/go/+/659956
Reviewed-by: Keith Randall <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Keith Randall <[email protected]>
Reviewed-by: Felix Geisendörfer <[email protected]>
(cherry picked from commit df9888e)
Reviewed-on: https://go-review.googlesource.com/c/go/+/682356

…ccount

TestImpersonated and TestGroupIdsTestUser are flaky due to sporadic
failures when creating the test user account when running the tests
from different processes at the same time.

This flakiness can be fixed by using a random name for the test user
account.

For #73523.
Fixes #74760.

Cq-Include-Trybots: luci.golang.try:go1.24-windows-amd64-longtest
Change-Id: Ib2283a888437420502b1c11d876c975f5af4bc03
Reviewed-on: https://go-review.googlesource.com/c/go/+/690175
Auto-Submit: Quim Muntal <[email protected]>
Reviewed-by: Michael Pratt <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
TryBot-Bypass: Dmitri Shuralyov <[email protected]>
(cherry picked from commit 374e3be)
Reviewed-on: https://go-review.googlesource.com/c/go/+/690556
Reviewed-by: Mark Freeman <[email protected]>
Reviewed-by: Quim Muntal <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Auto-Submit: Dmitri Shuralyov <[email protected]>

…t with a single instruction

That way, the frame is atomically popped. Previously, for big frames
the SP was unwound in two steps (because arm64 can only add constants
up to 1<<12 in a single instruction).

Fixes #74694

Change-Id: I382c249194ad7bc9fc19607c27487c58d90d49e5
Reviewed-on: https://go-review.googlesource.com/c/go/+/689235
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Michael Pratt <[email protected]>
Reviewed-by: Keith Randall <[email protected]>
(cherry picked from commit f7cc61e)
Reviewed-on: https://go-review.googlesource.com/c/go/+/689596

…nd ".." in LookPath

Fix incorrect expansion of "" and "." when $PATH contains an executable
file or, on Windows, a parent directory of a %PATH% element contains an
file with the same name as the %PATH% element but with one of the
%PATHEXT% extension (ex: C:\utils\bin is in PATH, and C:\utils\bin.exe
exists).

Fix incorrect expansion of ".." when $PATH contains an element which is
an the concatenation of the path to an executable file (or on Windows
a path that can be expanded to an executable by appending a %PATHEXT%
extension), a path separator and a name.

"", "." and ".." are now rejected early with ErrNotFound.

Fixes CVE-2025-47906
Fixes #74804

Change-Id: Ie50cc0a660fce8fbdc952a7f2e05c36062dcb50e
Reviewed-on: https://go-review.googlesource.com/c/go/+/685755
LUCI-TryBot-Result: Go LUCI <[email protected]>
Auto-Submit: Damien Neil <[email protected]>
Reviewed-by: Roland Shoemaker <[email protected]>
Reviewed-by: Damien Neil <[email protected]>
(cherry picked from commit e0b07dc)
Reviewed-on: https://go-review.googlesource.com/c/go/+/691875
Reviewed-by: Michael Knyszek <[email protected]>

…s in progress

A database/sql/driver.Rows can return database-owned data
from Rows.Next. The driver.Rows documentation doesn't explicitly
document the lifetime guarantees for this data, but a reasonable
expectation is that the caller of Next should only access it
until the next call to Rows.Close or Rows.Next.

Avoid violating that constraint when a query is cancelled while
a call to database/sql.Rows.Scan (note the difference between
the two different Rows types!) is in progress. We previously
took care to avoid closing a driver.Rows while the user has
access to driver-owned memory via a RawData, but we could still
close a driver.Rows while a Scan call was in the process of
reading previously-returned driver-owned data.

Update the fake DB used in database/sql tests to invalidate
returned data to help catch other places we might be
incorrectly retaining it.

Updates #74831
Fixes #74833

Change-Id: Ice45b5fad51b679c38e3e1d21ef39156b56d6037
Reviewed-on: https://go-internal-review.googlesource.com/c/go/+/2540
Reviewed-by: Roland Shoemaker <[email protected]>
Reviewed-by: Neal Patel <[email protected]>
Reviewed-on: https://go-internal-review.googlesource.com/c/go/+/2620
Reviewed-on: https://go-review.googlesource.com/c/go/+/693616
Reviewed-by: Dmitri Shuralyov <[email protected]>
Auto-Submit: Dmitri Shuralyov <[email protected]>
TryBot-Bypass: Dmitri Shuralyov <[email protected]>
Reviewed-by: Mark Freeman <[email protected]>

Change-Id: I01fc50fa6e6ea1bd93cbbd17885a8934bf97b223
Reviewed-on: https://go-review.googlesource.com/c/go/+/693715
Reviewed-by: Dmitri Shuralyov <[email protected]>
Auto-Submit: Gopher Robot <[email protected]>
TryBot-Bypass: Gopher Robot <[email protected]>
Reviewed-by: Mark Freeman <[email protected]>