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

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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.
This commit is contained in:
cinap_lenrek 2014-11-07 05:21:42 +01:00
parent 20cc2799af
commit a0e001a234
1 changed files with 1 additions and 1 deletions
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2
sys/src/9/port/devproc.c
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@ -1258,8 +1258,8 @@ procstopwait(Proc *p, int ctl)
qunlock(&p->debug); qunlock(&p->debug);
up->psstate = "Stopwait"; up->psstate = "Stopwait";
if(waserror()) { if(waserror()) {
p->pdbg = nil;
qlock(&p->debug); qlock(&p->debug);
p->pdbg = nil;
nexterror(); nexterror();
} }
sleep(&up->sleep, procstopped, p); sleep(&up->sleep, procstopped, p);