From 8d23b2080b4ffe530edc324f233c2a5bb192b152 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Tue, 7 Sep 2021 19:57:33 -0700
Subject: proc: stop using seq_get_buf in proc_task_name

Use seq_escape_str and seq_printf instead of poking holes into the
seq_file abstraction.

Link: https://lkml.kernel.org/r/20210810151945.1795567-1-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 fs/proc/array.c | 18 ++++--------------
 1 file changed, 4 insertions(+), 14 deletions(-)

(limited to 'fs/proc')

diff --git a/fs/proc/array.c b/fs/proc/array.c
index ee0ce8cecc4a..49be8c8ef555 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -98,27 +98,17 @@
 
 void proc_task_name(struct seq_file *m, struct task_struct *p, bool escape)
 {
-	char *buf;
-	size_t size;
 	char tcomm[64];
-	int ret;
 
 	if (p->flags & PF_WQ_WORKER)
 		wq_worker_comm(tcomm, sizeof(tcomm), p);
 	else
 		__get_task_comm(tcomm, sizeof(tcomm), p);
 
-	size = seq_get_buf(m, &buf);
-	if (escape) {
-		ret = string_escape_str(tcomm, buf, size,
-					ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\");
-		if (ret >= size)
-			ret = -1;
-	} else {
-		ret = strscpy(buf, tcomm, size);
-	}
-
-	seq_commit(m, ret);
+	if (escape)
+		seq_escape_str(m, tcomm, ESCAPE_SPACE | ESCAPE_SPECIAL, "\n\\");
+	else
+		seq_printf(m, "%.64s", tcomm);
 }
 
 /*
-- 
cgit v1.2.3


From c2f273ebd89a79ed87ef1025753343e327b99ac9 Mon Sep 17 00:00:00 2001
From: Ohhoon Kwon <ohoono.kwon@samsung.com>
Date: Tue, 7 Sep 2021 19:57:35 -0700
Subject: connector: send event on write to /proc/[pid]/comm

While comm change event via prctl has been reported to proc connector by
'commit f786ecba4158 ("connector: add comm change event report to proc
connector")', connector listeners were missing comm changes by explicit
writes on /proc/[pid]/comm.

Let explicit writes on /proc/[pid]/comm report to proc connector.

Link: https://lkml.kernel.org/r/20210701133458epcms1p68e9eb9bd0eee8903ba26679a37d9d960@epcms1p6
Signed-off-by: Ohhoon Kwon <ohoono.kwon@samsung.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 fs/proc/base.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

(limited to 'fs/proc')

diff --git a/fs/proc/base.c b/fs/proc/base.c
index e5b5f7709d48..533d5836eb9a 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -95,6 +95,7 @@
 #include <linux/posix-timers.h>
 #include <linux/time_namespace.h>
 #include <linux/resctrl.h>
+#include <linux/cn_proc.h>
 #include <trace/events/oom.h>
 #include "internal.h"
 #include "fd.h"
@@ -1674,8 +1675,10 @@ static ssize_t comm_write(struct file *file, const char __user *buf,
 	if (!p)
 		return -ESRCH;
 
-	if (same_thread_group(current, p))
+	if (same_thread_group(current, p)) {
 		set_task_comm(p, buffer);
+		proc_comm_connector(p);
+	}
 	else
 		count = -EINVAL;
 
-- 
cgit v1.2.3