Commit 79d4d38a authored Dec 14, 2020 by Joe Perches Committed by Linus Torvalds Dec 15, 2020

mm: shmem: convert shmem_enabled_show to use sysfs_emit_at

Update the function to use sysfs_emit_at while neatening the uses of
sprintf and overwriting the last space char with a newline to avoid
possible output buffer overflow.

Miscellanea:

 - in shmem_enabled_show, the removal of the indirected use of fmt
   allows __printf verification

Link: https://lkml.kernel.org/r/b612a93825e5ea330cb68d2e8b516e9687a06cc6.1605376435.git.joe@perches.com


Signed-off-by: Joe Perches <joe@perches.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 5e4c0d86

mm/shmem.c

+12 −9

Original line number	Diff line number	Diff line
		@@ -4030,16 +4030,19 @@ static ssize_t shmem_enabled_show(struct kobject *kobj,
		SHMEM_HUGE_DENY,
		SHMEM_HUGE_FORCE,
		};
		int i, count;

		for (i = 0, count = 0; i < ARRAY_SIZE(values); i++) {
		const char *fmt = shmem_huge == values[i] ? "[%s] " : "%s ";
		int len = 0;
		int i;

		count += sprintf(buf + count, fmt,
		for (i = 0; i < ARRAY_SIZE(values); i++) {
		len += sysfs_emit_at(buf, len,
		shmem_huge == values[i] ? "%s[%s]" : "%s%s",
		i ? " " : "",
		shmem_format_huge(values[i]));
		}
		buf[count - 1] = '\n';
		return count;

		len += sysfs_emit_at(buf, len, "\n");

		return len;
		}

		static ssize_t shmem_enabled_store(struct kobject *kobj,

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