re: kern/45647: kill from ddb broken

[Jared McNeill <jmcneill%invisible.ca@localhost>]

The following reply was made to PR kern/45647; it has been noted by GNATS.

From: Jared McNeill <jmcneill%invisible.ca@localhost>
To: matthew green <mrg%eterna.com.au@localhost>
Cc: gnats-bugs%NetBSD.org@localhost, kern-bug-people%netbsd.org@localhost, 
gnats-admin%netbsd.org@localhost, 
    netbsd-bugs%netbsd.org@localhost
Subject: re: kern/45647: kill from ddb broken
Date: Thu, 1 Dec 2011 07:18:43 -0500 (EST)

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 You could probably just mutex_tryenter(&proc_lock) and print a message if 
 it fails.
 
 On Thu, 1 Dec 2011, matthew green wrote:
 
 >
 >> Trying to kill a process from ddb fails:
 >>
 >> db{1}> kill 0t507
 >> Skipping crash dump on recursive panic
 >> panic: kernel diagnostic assertion "mutex_owned(proc_lock)" failed: file 
 >> "../../../../kern/kern_proc.c", line 590
 >
 > this is non trivial to solve.
 >
 > simply taking proc_lock (and more!) isn't going to work if some cpu
 > was stopped mid-lock of these.
 >
 > perhaps a solution would be to have ddb create a thread that will go
 > away that will send the signal asap...
 >
 >
 > .mrg.
 >
 >
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