shithub: riscv

Download patch

ref: a0e001a234796825f809e28c48880932b9e2aea9
parent: 20cc2799afd44ca156894fd96a1a72b61fc8a63a
author: cinap_lenrek <[email protected]>
date: Fri Nov 7 00:21:42 EST 2014

devproc: reset p->pdbg under p->debug qlock in procstopwait()

theres a race where procstopwait() is interrupted by a note,
setting p->pdbg to nil *before* acquiering the lock and
and pexit() and procctl() accessing it assuming it doesnt
change under them while they are holding the lock.

--- a/sys/src/9/port/devproc.c

+++ b/sys/src/9/port/devproc.c

@@ -1258,8 +1258,8 @@

 	qunlock(&p->debug);

 	up->psstate = "Stopwait";

 	if(waserror()) {

-		p->pdbg = nil;

 		qlock(&p->debug);

+		p->pdbg = nil;

 		nexterror();

 	}

 	sleep(&up->sleep, procstopped, p);