[PATCH] mm/memory-failure.c: send "action optional" signal to an arbitrary thread

[Kamil Iskra <iskra@mcs.anl.gov>]

Please find below a trivial patch that changes the sending of BUS_MCEERR_AO
SIGBUS signals so that they can be handled by an arbitrary thread of the
target process.  The current implementation makes it impossible to create a
separate, dedicated thread to handle such errors, as the signal is always
sent to the main thread.

Also, do I understand it correctly that "action required" faults *must* be
handled by the thread that triggered the error?  I guess it makes sense for
it to be that way, even if it circumvents the "dedicated handling thread"
idea...

The patch is against the 3.12.4 kernel.

--- mm/memory-failure.c.orig	2013-12-08 10:18:58.000000000 -0600
+++ mm/memory-failure.c	2013-12-12 11:43:03.973334767 -0600
@@ -219,7 +219,7 @@ static int kill_proc(struct task_struct
 		 * to SIG_IGN, but hopefully no one will do that?
 		 */
 		si.si_code = BUS_MCEERR_AO;
-		ret = send_sig_info(SIGBUS, &si, t);  /* synchronous? */
+		ret = group_send_sig_info(SIGBUS, &si, t);  /* synchronous? */
 	}
 	if (ret < 0)
 		printk(KERN_INFO "MCE: Error sending signal to %s:%d: %d\n",

Thanks,

Kamil

-- 
Kamil Iskra, PhD
Argonne National Laboratory, Mathematics and Computer Science Division
9700 South Cass Avenue, Building 240, Argonne, IL 60439, USA
phone: +1-630-252-7197  fax: +1-630-252-5986

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