Merge remote-tracking branch 'torvalds/master' into perf/core

To pick up the fixes sent for v5.12 and continue development based on
v5.12-rc2, i.e. without the swap on file bug.

This also gets a slightly newer and better tools/perf/arch/arm/util/cs-etm.c
patch version, using the BIT() macro, that had already been slated to
v5.13 but ended up going to v5.12-rc1 on an older version.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 25 insertions, 15 deletions

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index e9481632fcd1b..24210c9bd8434 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -243,9 +243,13 @@ static int kill_proc(struct to_kill *tk, unsigned long pfn, int flags)
 			pfn, t->comm, t->pid);
 
 	if (flags & MF_ACTION_REQUIRED) {
-		WARN_ON_ONCE(t != current);
-		ret = force_sig_mceerr(BUS_MCEERR_AR,
+		if (t == current)
+			ret = force_sig_mceerr(BUS_MCEERR_AR,
 					 (void __user *)tk->addr, addr_lsb);
+		else
+			/* Signal other processes sharing the page if they have PF_MCE_EARLY set. */
+			ret = send_sig_mceerr(BUS_MCEERR_AO, (void __user *)tk->addr,
+				addr_lsb, t);
 	} else {
 		/*
 		 * Don't use force here, it's convenient if the signal
@@ -440,26 +444,26 @@ static struct task_struct *find_early_kill_thread(struct task_struct *tsk)
  * Determine whether a given process is "early kill" process which expects
  * to be signaled when some page under the process is hwpoisoned.
  * Return task_struct of the dedicated thread (main thread unless explicitly
- * specified) if the process is "early kill," and otherwise returns NULL.
+ * specified) if the process is "early kill" and otherwise returns NULL.
  *
- * Note that the above is true for Action Optional case, but not for Action
- * Required case where SIGBUS should sent only to the current thread.
+ * Note that the above is true for Action Optional case. For Action Required
+ * case, it's only meaningful to the current thread which need to be signaled
+ * with SIGBUS, this error is Action Optional for other non current
+ * processes sharing the same error page,if the process is "early kill", the
+ * task_struct of the dedicated thread will also be returned.
  */
 static struct task_struct *task_early_kill(struct task_struct *tsk,
 					   int force_early)
 {
 	if (!tsk->mm)
 		return NULL;
-	if (force_early) {
-		/*
-		 * Comparing ->mm here because current task might represent
-		 * a subthread, while tsk always points to the main thread.
-		 */
-		if (tsk->mm == current->mm)
-			return current;
-		else
-			return NULL;
-	}
+	/*
+	 * Comparing ->mm here because current task might represent
+	 * a subthread, while tsk always points to the main thread.
+	 */
+	if (force_early && tsk->mm == current->mm)
+		return current;
+
 	return find_early_kill_thread(tsk);
 }
 
@@ -1308,6 +1312,12 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags,
 		 */
 		put_page(page);
 
+	/* device metadata space is not recoverable */
+	if (!pgmap_pfn_valid(pgmap, pfn)) {
+		rc = -ENXIO;
+		goto out;
+	}
+
 	/*
 	 * Prevent the inode from being freed while we are interrogating
 	 * the address_space, typically this would be handled by