From: Joe Perches <joe@xxxxxxxxxxx> Subject: 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: o 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@xxxxxxxxxxx Signed-off-by: Joe Perches <joe@xxxxxxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/shmem.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) --- a/mm/shmem.c~mm-shmem-convert-shmem_enabled_show-to-use-sysfs_emit_at +++ a/mm/shmem.c @@ -4020,7 +4020,7 @@ out2: #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && defined(CONFIG_SYSFS) static ssize_t shmem_enabled_show(struct kobject *kobj, - struct kobj_attribute *attr, char *buf) + struct kobj_attribute *attr, char *buf) { static const int values[] = { SHMEM_HUGE_ALWAYS, @@ -4030,16 +4030,19 @@ static ssize_t shmem_enabled_show(struct SHMEM_HUGE_DENY, SHMEM_HUGE_FORCE, }; - int i, count; + int len = 0; + int i; - for (i = 0, count = 0; i < ARRAY_SIZE(values); i++) { - const char *fmt = shmem_huge == values[i] ? "[%s] " : "%s "; - - count += sprintf(buf + count, fmt, - shmem_format_huge(values[i])); + 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, _
