linux-kernel - [PATCH] mm, memory_failure: only send BUS_MCEERR

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Message-Id: <1590476801-19882-1-git-send-email-wetp.zy@linux.alibaba.com>
Date:   Tue, 26 May 2020 15:06:41 +0800
From:   Wetp Zhang <wetp.zy@...ux.alibaba.com>
To:     n-horiguchi@...jp.nec.com, akpm@...ux-foundation.org
Cc:     linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: [PATCH] mm, memory_failure: only send BUS_MCEERR_AO to early-kill process

From: Zhang Yi <wetpzy@...il.com>

If a process don't need early-kill, it may not care the BUS_MCEERR_AO.
Let the process to be killed when it really access the corrupted memory.

Signed-off-by: Zhang Yi <wetpzy@...il.com>
---
 mm/memory-failure.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index a96364be8ab4..2db13d48865c 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -210,7 +210,7 @@ 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);
@@ -225,8 +225,9 @@ static int kill_proc(struct to_kill *tk, unsigned long pfn, int flags)
 		 * This could cause a loop when the user sets SIGBUS
 		 * to SIG_IGN, but hopefully no one will do that?
 		 */
-		ret = send_sig_mceerr(BUS_MCEERR_AO, (void __user *)tk->addr,
-				      addr_lsb, t);  /* synchronous? */
+		if ((t->flags & PF_MCE_PROCESS) && (t->flags & PF_MCE_EARLY))
+			ret = send_sig_mceerr(BUS_MCEERR_AO,
+				(void __user *)tk->addr, addr_lsb, t);
 	}
 	if (ret < 0)
 		pr_info("Memory failure: Error sending signal to %s:%d: %d\n",
-- 
2.14.3 (Apple Git-98)