runtime: accept restartable sequence pcdata values in isAsyncSafePoint

If the pcdata value indicates a restartable sequence, it is okay
to asynchronously preempt (and resume at the restart PC). Accept
it in isAsyncSafePoint.

Fixes #47530.

Change-Id: I419225717c8eee5812f3235338262da5895aad0d
Reviewed-on: https://go-review.googlesource.com/c/go/+/340011
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
Reviewed-by: Joel Sing <joel@sing.id.au>
Reviewed-by: Austin Clements <austin@google.com>
This commit is contained in:
Cherry Mui 2021-08-04 19:41:19 -04:00
parent df9c5d8f5d
commit 8ff16c1990

View file

@ -399,7 +399,7 @@ func isAsyncSafePoint(gp *g, pc, sp, lr uintptr) (bool, uintptr) {
return false, 0
}
up, startpc := pcdatavalue2(f, _PCDATA_UnsafePoint, pc)
if up != _PCDATA_UnsafePointSafe {
if up == _PCDATA_UnsafePointUnsafe {
// Unsafe-point marked by compiler. This includes
// atomic sequences (e.g., write barrier) and nosplit
// functions (except at calls).