From: Miles Chen <miles.chen@xxxxxxxxxxxx> The kbuf used by page owner is allocated by kmalloc(), which means it can use only normal memory and there might be a "out of memory" issue when we're out of normal memory. Use kvmalloc() so we can also allocate kbuf from normal/hihghmem on 32bit kernel. Clamp the kbuf size to PAGE_SIZE. Change since v1: - use kvmalloc() - clamp buffer size to PAGE_SIZE Signed-off-by: Miles Chen <miles.chen@xxxxxxxxxxxx> Cc: Joe Perches <joe@xxxxxxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> --- mm/page_owner.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/mm/page_owner.c b/mm/page_owner.c index d80adfe..a064cd0 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -1,7 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/debugfs.h> #include <linux/mm.h> -#include <linux/slab.h> #include <linux/uaccess.h> #include <linux/bootmem.h> #include <linux/stacktrace.h> @@ -351,7 +350,8 @@ void pagetypeinfo_showmixedcount_print(struct seq_file *m, .skip = 0 }; - kbuf = kmalloc(count, GFP_KERNEL); + count = count > PAGE_SIZE ? PAGE_SIZE : count; + kbuf = kvmalloc(count, GFP_KERNEL); if (!kbuf) return -ENOMEM; @@ -397,11 +397,11 @@ void pagetypeinfo_showmixedcount_print(struct seq_file *m, if (copy_to_user(buf, kbuf, ret)) ret = -EFAULT; - kfree(kbuf); + kvfree(kbuf); return ret; err: - kfree(kbuf); + kvfree(kbuf); return -ENOMEM; } -- 1.9.1
