On Thu, 2018-10-25 at 11:44 -0700, Joe Perches wrote: > 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. thanks for the advise. kvmalloc/kvfree is better here. > > > 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; > > } > > >
