Commit 64212ec5 authored by Akinobu Mita's avatar Akinobu Mita Committed by Linus Torvalds

debug-pagealloc: add support for highmem pages

This adds support for highmem pages poisoning and verification to the
debug-pagealloc feature for no-architecture support.

[akpm@linux-foundation.org: remove unneeded preempt_disable/enable]
Signed-off-by: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3ee9a4f0
#include <linux/kernel.h> #include <linux/kernel.h>
#include <linux/string.h> #include <linux/string.h>
#include <linux/mm.h> #include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/page-debug-flags.h> #include <linux/page-debug-flags.h>
#include <linux/poison.h> #include <linux/poison.h>
#include <linux/ratelimit.h> #include <linux/ratelimit.h>
...@@ -20,28 +21,13 @@ static inline bool page_poison(struct page *page) ...@@ -20,28 +21,13 @@ static inline bool page_poison(struct page *page)
return test_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags); return test_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags);
} }
static void poison_highpage(struct page *page)
{
/*
* Page poisoning for highmem pages is not implemented.
*
* This can be called from interrupt contexts.
* So we need to create a new kmap_atomic slot for this
* application and it will need interrupt protection.
*/
}
static void poison_page(struct page *page) static void poison_page(struct page *page)
{ {
void *addr; void *addr = kmap_atomic(page);
if (PageHighMem(page)) {
poison_highpage(page);
return;
}
set_page_poison(page); set_page_poison(page);
addr = page_address(page);
memset(addr, PAGE_POISON, PAGE_SIZE); memset(addr, PAGE_POISON, PAGE_SIZE);
kunmap_atomic(addr);
} }
static void poison_pages(struct page *page, int n) static void poison_pages(struct page *page, int n)
...@@ -86,27 +72,17 @@ static void check_poison_mem(unsigned char *mem, size_t bytes) ...@@ -86,27 +72,17 @@ static void check_poison_mem(unsigned char *mem, size_t bytes)
dump_stack(); dump_stack();
} }
static void unpoison_highpage(struct page *page)
{
/*
* See comment in poison_highpage().
* Highmem pages should not be poisoned for now
*/
BUG_ON(page_poison(page));
}
static void unpoison_page(struct page *page) static void unpoison_page(struct page *page)
{ {
if (PageHighMem(page)) { void *addr;
unpoison_highpage(page);
if (!page_poison(page))
return; return;
}
if (page_poison(page)) {
void *addr = page_address(page);
addr = kmap_atomic(page);
check_poison_mem(addr, PAGE_SIZE); check_poison_mem(addr, PAGE_SIZE);
clear_page_poison(page); clear_page_poison(page);
} kunmap_atomic(addr);
} }
static void unpoison_pages(struct page *page, int n) static void unpoison_pages(struct page *page, int n)
......
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