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| author | Michael Anthony Knyszek <mknyszek@google.com> | 2024-04-22 15:24:42 +0000 |
|---|---|---|
| committer | Michael Knyszek <mknyszek@google.com> | 2024-04-23 02:53:00 +0000 |
| commit | 0304d035cd1a35762b0d1e394f13345e29107b63 (patch) | |
| tree | 497ed3bd5e97c216ec7b6a7e7d0683e753eb48df | |
| parent | 9702cd980fadefe4d6740a52d32fb1ad52e984cc (diff) | |
| download | go-0304d035cd1a35762b0d1e394f13345e29107b63.tar.gz go-0304d035cd1a35762b0d1e394f13345e29107b63.zip | |
runtime: switch to systemstack before throw in casgstatus
CL 580255 increased the frame size of entersyscall and reentersyscall,
which is causing the x/sys repository to fail to build for
windows/arm64 because of an overflow of the nosplit stack reservation.
Fix this by wrapping the other call to throw in casgstatus in a system
stack switch. This is a fatal throw anyway indicating a core runtime
invariant is broken, so this path is basically never taken. This cuts
off the nosplit frame chain and allows x/sys to build.
Change-Id: I00b16c9db3a7467413ed48953c7f8a9a750f000a
Reviewed-on: https://go-review.googlesource.com/c/go/+/580775
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
| -rw-r--r-- | src/runtime/proc.go | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/src/runtime/proc.go b/src/runtime/proc.go index e469f20e5e..56f97fa9f7 100644 --- a/src/runtime/proc.go +++ b/src/runtime/proc.go @@ -1105,6 +1105,8 @@ var casgstatusAlwaysTrack = false func casgstatus(gp *g, oldval, newval uint32) { if (oldval&_Gscan != 0) || (newval&_Gscan != 0) || oldval == newval { systemstack(func() { + // Call on the systemstack to prevent print and throw from counting + // against the nosplit stack reservation. print("runtime: casgstatus: oldval=", hex(oldval), " newval=", hex(newval), "\n") throw("casgstatus: bad incoming values") }) @@ -1120,7 +1122,11 @@ func casgstatus(gp *g, oldval, newval uint32) { // GC time to finish and change the state to oldval. for i := 0; !gp.atomicstatus.CompareAndSwap(oldval, newval); i++ { if oldval == _Gwaiting && gp.atomicstatus.Load() == _Grunnable { - throw("casgstatus: waiting for Gwaiting but is Grunnable") + systemstack(func() { + // Call on the systemstack to prevent throw from counting + // against the nosplit stack reservation. + throw("casgstatus: waiting for Gwaiting but is Grunnable") + }) } if i == 0 { nextYield = nanotime() + yieldDelay |