[PATCH V2] mm, memory_failure: don't send BUS_MCEERR_AO for action required error

[Wetp Zhang]

Some processes dont't want to be killed early, but in "Action Required"
case, those also may be killed by BUS_MCEERR_AO when sharing memory
with other which is accessing the fail memory.
And sending SIGBUS with BUS_MCEERR_AO for action required error is
strange, so ignore the non-current processes here.

Suggested-by: Naoya Horiguchi <naoya.horigu...@nec.com>
Signed-off-by: Wetp Zhang <wetp...@linux.alibaba.com>
---
 mm/memory-failure.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index a96364be8ab4..dd3862fcf2e9 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -210,14 +210,17 @@ static int kill_proc(struct to_kill *tk, unsigned long 
pfn, int flags)
 {
        struct task_struct *t = tk->tsk;
        short addr_lsb = tk->size_shift;
-       int ret;
+       int ret = 0;
 
-       pr_err("Memory failure: %#lx: Sending SIGBUS to %s:%d due to hardware 
memory corruption\n",
-               pfn, t->comm, t->pid);
+       if ((t->mm == current->mm) || !(flags & MF_ACTION_REQUIRED))
+               pr_err("Memory failure: %#lx: Sending SIGBUS to %s:%d due to 
hardware memory corruption\n",
+                       pfn, t->comm, t->pid);
 
-       if ((flags & MF_ACTION_REQUIRED) && t->mm == current->mm) {
-               ret = force_sig_mceerr(BUS_MCEERR_AR, (void __user *)tk->addr,
-                                      addr_lsb);
+       if (flags & MF_ACTION_REQUIRED) {
+               if (t->mm == current->mm)
+                       ret = force_sig_mceerr(BUS_MCEERR_AR,
+                                        (void __user *)tk->addr, addr_lsb);
+               /* send no signal to non-current processes */
        } else {
                /*
                 * Don't use force here, it's convenient if the signal
-- 
2.14.3 (Apple Git-98)