On Fri, 2018-10-26 at 02:34 +0800, miles.chen@xxxxxxxxxxxx wrote: > 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 vmalloc() so we can also allocate kbuf from highmem > on 32bit kernel. If this is really necessary, using kvmalloc/kvfree would be better as the vmalloc space is also limited. > diff --git 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> > @@ -10,6 +9,7 @@ > #include <linux/migrate.h> > #include <linux/stackdepot.h> > #include <linux/seq_file.h> > +#include <linux/vmalloc.h> > > #include "internal.h" > > @@ -351,7 +351,7 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn, > .skip = 0 > }; > > - kbuf = kmalloc(count, GFP_KERNEL); > + kbuf = vmalloc(count); > if (!kbuf) > return -ENOMEM; > > @@ -397,11 +397,11 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn, > if (copy_to_user(buf, kbuf, ret)) > ret = -EFAULT; > > - kfree(kbuf); > + vfree(kbuf); > return ret; > > err: > - kfree(kbuf); > + vfree(kbuf); > return -ENOMEM; > } >
