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Diffstat (limited to 'mm/debug-pagealloc.c')
-rw-r--r--mm/debug-pagealloc.c56
1 files changed, 16 insertions, 40 deletions
diff --git a/mm/debug-pagealloc.c b/mm/debug-pagealloc.c
index a1e3324de2b5..7cea557407f4 100644
--- a/mm/debug-pagealloc.c
+++ b/mm/debug-pagealloc.c
@@ -1,7 +1,10 @@
#include <linux/kernel.h>
+#include <linux/string.h>
#include <linux/mm.h>
+#include <linux/highmem.h>
#include <linux/page-debug-flags.h>
#include <linux/poison.h>
+#include <linux/ratelimit.h>
static inline void set_page_poison(struct page *page)
{
@@ -18,28 +21,13 @@ static inline bool page_poison(struct page *page)
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)
{
- void *addr;
+ void *addr = kmap_atomic(page);
- if (PageHighMem(page)) {
- poison_highpage(page);
- return;
- }
set_page_poison(page);
- addr = page_address(page);
memset(addr, PAGE_POISON, PAGE_SIZE);
+ kunmap_atomic(addr);
}
static void poison_pages(struct page *page, int n)
@@ -59,14 +47,12 @@ static bool single_bit_flip(unsigned char a, unsigned char b)
static void check_poison_mem(unsigned char *mem, size_t bytes)
{
+ static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 10);
unsigned char *start;
unsigned char *end;
- for (start = mem; start < mem + bytes; start++) {
- if (*start != PAGE_POISON)
- break;
- }
- if (start == mem + bytes)
+ start = memchr_inv(mem, PAGE_POISON, bytes);
+ if (!start)
return;
for (end = mem + bytes - 1; end > start; end--) {
@@ -74,7 +60,7 @@ static void check_poison_mem(unsigned char *mem, size_t bytes)
break;
}
- if (!printk_ratelimit())
+ if (!__ratelimit(&ratelimit))
return;
else if (start == end && single_bit_flip(*start, PAGE_POISON))
printk(KERN_ERR "pagealloc: single bit error\n");
@@ -86,27 +72,17 @@ static void check_poison_mem(unsigned char *mem, size_t bytes)
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)
{
- if (PageHighMem(page)) {
- unpoison_highpage(page);
+ void *addr;
+
+ if (!page_poison(page))
return;
- }
- if (page_poison(page)) {
- void *addr = page_address(page);
- check_poison_mem(addr, PAGE_SIZE);
- clear_page_poison(page);
- }
+ addr = kmap_atomic(page);
+ check_poison_mem(addr, PAGE_SIZE);
+ clear_page_poison(page);
+ kunmap_atomic(addr);
}
static void unpoison_pages(struct page *page, int n)