A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-28 18:51:56 -04:00
Code Issues Projects Releases Packages Wiki Activity

generic debug pagealloc

Browse source 
CONFIG_DEBUG_PAGEALLOC is now supported by x86, powerpc, sparc64, and
s390.  This patch implements it for the rest of the architectures by
filling the pages with poison byte patterns after free_pages() and
verifying the poison patterns before alloc_pages().

This generic one cannot detect invalid page accesses immediately but
invalid read access may cause invalid dereference by poisoned memory and
invalid write access can be detected after a long delay.

Signed-off-by: Akinobu Mita <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Akinobu Mita 2009-03-31 15:23:17 -07:00 • committed by Linus Torvalds
commit 6a11f75b6a
16 changed files with 202 additions and 19 deletions
Download patch file Download diff file Expand all files Collapse all files

4
include/linux/mm_types.h
View file

@ -11,6 +11,7 @@
#include <linux/rwsem.h>
#include <linux/completion.h>
#include <linux/cpumask.h>
#include <linux/page-debug-flags.h>
#include <asm/page.h>
#include <asm/mmu.h>
@ -174,6 +175,9 @@ struct vm_area_struct {
#ifdef CONFIG_NUMA
struct mempolicy *vm_policy; /* NUMA policy for the VMA */
#endif
#ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
unsigned long debug_flags; /* Use atomic bitops on this */
#endif
};
struct core_thread {

30
include/linux/page-debug-flags.h Normal file
View file

@ -0,0 +1,30 @@
#ifndef LINUX_PAGE_DEBUG_FLAGS_H
#define LINUX_PAGE_DEBUG_FLAGS_H
/*
* page->debug_flags bits:
*
* PAGE_DEBUG_FLAG_POISON is set for poisoned pages. This is used to
* implement generic debug pagealloc feature. The pages are filled with
* poison patterns and set this flag after free_pages(). The poisoned
* pages are verified whether the patterns are not corrupted and clear
* the flag before alloc_pages().
*/
enum page_debug_flags {
PAGE_DEBUG_FLAG_POISON, /* Page is poisoned */
};
/*
* Ensure that CONFIG_WANT_PAGE_DEBUG_FLAGS reliably
* gets turned off when no debug features are enabling it!
*/
#ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
#if !defined(CONFIG_PAGE_POISONING) \
/* && !defined(CONFIG_PAGE_DEBUG_SOMETHING_ELSE) && ... */
#error WANT_PAGE_DEBUG_FLAGS is turned on with no debug features!
#endif
#endif /* CONFIG_WANT_PAGE_DEBUG_FLAGS */
#endif /* LINUX_PAGE_DEBUG_FLAGS_H */

3
include/linux/poison.h
View file

@ -17,6 +17,9 @@
*/
#define TIMER_ENTRY_STATIC ((void *) 0x74737461)
/********** mm/debug-pagealloc.c **********/
#define PAGE_POISON 0xaa
/********** mm/slab.c **********/
/*
* Magic nums for obj red zoning.