runtime: fix panic if newstack at runtime.acquireLockRank
Process may crash becaues acquireLockRank and releaseLockRank may
be called in nosplit context. With optimizations and inlining
disabled, these functions won't get inlined or have their morestack
calls eliminated.
Nosplit is not strictly required for lockWithRank, unlockWithRank
and lockWithRankMayAcquire, just keep consistency with lockrank_on.go
here.
Fixes #40843
Change-Id: I5824119f98a1da66d767cdb9a60dffe768f13c81
GitHub-Last-Rev: 38fd3ccf6ea03b670c7561c060ccdbccc42fff40
GitHub-Pull-Request: golang/go#40844
Reviewed-on: https://go-review.googlesource.com/c/go/+/248878
Reviewed-by: Dan Scales <danscales@google.com>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/src/runtime/lockrank_off.go b/src/runtime/lockrank_off.go
index 425ca8d..32378a9 100644
--- a/src/runtime/lockrank_off.go
+++ b/src/runtime/lockrank_off.go
@@ -18,19 +18,29 @@
return 0
}
+// The following functions may be called in nosplit context.
+// Nosplit is not strictly required for lockWithRank, unlockWithRank
+// and lockWithRankMayAcquire, but these nosplit annotations must
+// be kept consistent with the equivalent functions in lockrank_on.go.
+
+//go:nosplit
func lockWithRank(l *mutex, rank lockRank) {
lock2(l)
}
+//go:nosplit
func acquireLockRank(rank lockRank) {
}
+//go:nosplit
func unlockWithRank(l *mutex) {
unlock2(l)
}
+//go:nosplit
func releaseLockRank(rank lockRank) {
}
+//go:nosplit
func lockWithRankMayAcquire(l *mutex, rank lockRank) {
}
