runtime: always update stack bounds on cgocallback

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>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

0 files changed, 0 insertions, 0 deletions