runtime: prevent double lock in checkdead by unlocking before throws
This change resolves an issue where checkdead could result in a double lock when shedtrace is enabled. This fix involves adding unlocks before all throws in the checkdead function to ensure the scheduler lock is properly released.
Fixes #59758
Change-Id: If3ddf9969f4582c3c88dee9b9ecc355a63958103
Reviewed-on: https://go-review.googlesource.com/c/go/+/487375
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
diff --git a/src/runtime/proc.go b/src/runtime/proc.go
index 23d760b..fdbf888 100644
--- a/src/runtime/proc.go
+++ b/src/runtime/proc.go
@@ -5194,6 +5194,7 @@
}
if run < 0 {
print("runtime: checkdead: nmidle=", sched.nmidle, " nmidlelocked=", sched.nmidlelocked, " mcount=", mcount(), " nmsys=", sched.nmsys, "\n")
+ unlock(&sched.lock)
throw("checkdead: inconsistent counts")
}
@@ -5211,6 +5212,7 @@
_Grunning,
_Gsyscall:
print("runtime: checkdead: find g ", gp.goid, " in status ", s, "\n")
+ unlock(&sched.lock)
throw("checkdead: runnable g")
}
})
@@ -5229,12 +5231,14 @@
if pp == nil {
// There should always be a free P since
// nothing is running.
+ unlock(&sched.lock)
throw("checkdead: no p for timer")
}
mp := mget()
if mp == nil {
// There should always be a free M since
// nothing is running.
+ unlock(&sched.lock)
throw("checkdead: no m for timer")
}
// M must be spinning to steal. We set this to be
