This is a note to let you know that I've just added the patch titled
mm/memory-failure.c-failure: send right signal code to correct thread
to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-memory-failure.c-failure-send-right-signal-code-to-correct-thread.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a70ffcac741d31a406c1d2b832ae43d658e7e1cf Mon Sep 17 00:00:00 2001
From: Tony Luck <tony.luck@xxxxxxxxx>
Date: Wed, 4 Jun 2014 16:10:59 -0700
Subject: mm/memory-failure.c-failure: send right signal code to correct thread
From: Tony Luck <tony.luck@xxxxxxxxx>
commit a70ffcac741d31a406c1d2b832ae43d658e7e1cf upstream.
When a thread in a multi-threaded application hits a machine check because
of an uncorrectable error in memory - we want to send the SIGBUS with
si.si_code = BUS_MCEERR_AR to that thread. Currently we fail to do that
if the active thread is not the primary thread in the process.
collect_procs() just finds primary threads and this test:
if ((flags & MF_ACTION_REQUIRED) && t == current) {
will see that the thread we found isn't the current thread and so send a
si.si_code = BUS_MCEERR_AO to the primary (and nothing to the active
thread at this time).
We can fix this by checking whether "current" shares the same mm with the
process that collect_procs() said owned the page. If so, we send the
SIGBUS to current (with code BUS_MCEERR_AR).
Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Reported-by: Otto Bruggeman <otto.g.bruggeman@xxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Chen Gong <gong.chen@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/memory-failure.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -208,9 +208,9 @@ static int kill_proc(struct task_struct
#endif
si.si_addr_lsb = compound_order(compound_head(page)) + PAGE_SHIFT;
- if ((flags & MF_ACTION_REQUIRED) && t == current) {
+ if ((flags & MF_ACTION_REQUIRED) && t->mm == current->mm) {
si.si_code = BUS_MCEERR_AR;
- ret = force_sig_info(SIGBUS, &si, t);
+ ret = force_sig_info(SIGBUS, &si, current);
} else {
/*
* Don't use force here, it's convenient if the signal
Patches currently in stable-queue which might be from tony.luck@xxxxxxxxx are
queue-3.14/mm-memory-failure.c-failure-send-right-signal-code-to-correct-thread.patch
queue-3.14/mm-memory-failure.c-don-t-let-collect_procs-skip-over-processes-for-mf_action_required.patch
queue-3.14/hugetlb-restrict-hugepage_migration_support-to-x86_64.patch
queue-3.14/mm-memory-failure.c-support-use-of-a-dedicated-thread-to-handle-sigbus-bus_mceerr_ao.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html