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| author | Michael Anthony Knyszek <mknyszek@google.com> | 2021-11-03 18:49:51 +0000 |
|---|---|---|
| committer | Michael Knyszek <mknyszek@google.com> | 2021-11-05 17:52:30 +0000 |
| commit | df1837799d418eed6b4921cd1252dd8eae76cd98 (patch) | |
| tree | 48e37a8198b3aef339b91bebf78e0f2abc658637 /src/runtime | |
| parent | 6f32d2050d7f0a9d0c529a1a7a21aa8c1d63fa20 (diff) | |
| download | go-df1837799d418eed6b4921cd1252dd8eae76cd98.tar.xz | |
runtime: make consistentHeapStats acquire/release nosplit
consistentHeapStats is updated during a stack allocation, so a stack
growth during an acquire or release could cause another acquire to
happen before the operation completes fully. This may lead to an invalid
sequence number.
Fixes #49395.
Change-Id: I41ce3393dff80201793e053d4d6394d7b211a5b7
Reviewed-on: https://go-review.googlesource.com/c/go/+/361158
Trust: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Austin Clements <austin@google.com>
Diffstat (limited to 'src/runtime')
| -rw-r--r-- | src/runtime/mstats.go | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/src/runtime/mstats.go b/src/runtime/mstats.go index 341ba9a936..c2303e5b8e 100644 --- a/src/runtime/mstats.go +++ b/src/runtime/mstats.go @@ -790,7 +790,15 @@ type consistentHeapStats struct { // // The caller's P must not change between acquire and // release. This also means that the caller should not -// acquire a P or release its P in between. +// acquire a P or release its P in between. A P also must +// not acquire a given consistentHeapStats if it hasn't +// yet released it. +// +// nosplit because a stack growth in this function could +// lead to a stack allocation that could reenter the +// function. +// +//go:nosplit func (m *consistentHeapStats) acquire() *heapStatsDelta { if pp := getg().m.p.ptr(); pp != nil { seq := atomic.Xadd(&pp.statsSeq, 1) @@ -814,6 +822,12 @@ func (m *consistentHeapStats) acquire() *heapStatsDelta { // The caller's P must not change between acquire and // release. This also means that the caller should not // acquire a P or release its P in between. +// +// nosplit because a stack growth in this function could +// lead to a stack allocation that causes another acquire +// before this operation has completed. +// +//go:nosplit func (m *consistentHeapStats) release() { if pp := getg().m.p.ptr(); pp != nil { seq := atomic.Xadd(&pp.statsSeq, 1) |