4eace7df06
Currently, we just print the pagealloc corruption warnings and proceed. Sometimes, we are getting multiple errors printed down the line. It will be good to get the device state as early as possible when we get the first pagealloc error. Change-Id: I79155ac8a039b30a3a98d5dd1384d3923082712f Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org> Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
148 lines
2.8 KiB
C
148 lines
2.8 KiB
C
#include <linux/kernel.h>
|
|
#include <linux/string.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/highmem.h>
|
|
#include <linux/page_ext.h>
|
|
#include <linux/poison.h>
|
|
#include <linux/ratelimit.h>
|
|
|
|
#ifndef mark_addr_rdonly
|
|
#define mark_addr_rdonly(a)
|
|
#endif
|
|
|
|
#ifndef mark_addr_rdwrite
|
|
#define mark_addr_rdwrite(a)
|
|
#endif
|
|
|
|
static bool page_poisoning_enabled __read_mostly;
|
|
|
|
static bool need_page_poisoning(void)
|
|
{
|
|
if (!debug_pagealloc_enabled())
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
static void init_page_poisoning(void)
|
|
{
|
|
if (!debug_pagealloc_enabled())
|
|
return;
|
|
|
|
page_poisoning_enabled = true;
|
|
}
|
|
|
|
struct page_ext_operations page_poisoning_ops = {
|
|
.need = need_page_poisoning,
|
|
.init = init_page_poisoning,
|
|
};
|
|
|
|
static inline void set_page_poison(struct page *page)
|
|
{
|
|
struct page_ext *page_ext;
|
|
|
|
page_ext = lookup_page_ext(page);
|
|
__set_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags);
|
|
}
|
|
|
|
static inline void clear_page_poison(struct page *page)
|
|
{
|
|
struct page_ext *page_ext;
|
|
|
|
page_ext = lookup_page_ext(page);
|
|
__clear_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags);
|
|
}
|
|
|
|
static inline bool page_poison(struct page *page)
|
|
{
|
|
struct page_ext *page_ext;
|
|
|
|
page_ext = lookup_page_ext(page);
|
|
return test_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags);
|
|
}
|
|
|
|
static void poison_page(struct page *page)
|
|
{
|
|
void *addr = kmap_atomic(page);
|
|
|
|
set_page_poison(page);
|
|
memset(addr, PAGE_POISON, PAGE_SIZE);
|
|
mark_addr_rdonly(addr);
|
|
kunmap_atomic(addr);
|
|
}
|
|
|
|
static void poison_pages(struct page *page, int n)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < n; i++)
|
|
poison_page(page + i);
|
|
}
|
|
|
|
static bool single_bit_flip(unsigned char a, unsigned char b)
|
|
{
|
|
unsigned char error = a ^ b;
|
|
|
|
return error && !(error & (error - 1));
|
|
}
|
|
|
|
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;
|
|
|
|
start = memchr_inv(mem, PAGE_POISON, bytes);
|
|
if (!start)
|
|
return;
|
|
|
|
for (end = mem + bytes - 1; end > start; end--) {
|
|
if (*end != PAGE_POISON)
|
|
break;
|
|
}
|
|
|
|
if (!__ratelimit(&ratelimit))
|
|
return;
|
|
else if (start == end && single_bit_flip(*start, PAGE_POISON))
|
|
printk(KERN_ERR "pagealloc: single bit error\n");
|
|
else
|
|
printk(KERN_ERR "pagealloc: memory corruption\n");
|
|
|
|
print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1, start,
|
|
end - start + 1, 1);
|
|
BUG_ON(PANIC_CORRUPTION);
|
|
dump_stack();
|
|
}
|
|
|
|
static void unpoison_page(struct page *page)
|
|
{
|
|
void *addr;
|
|
|
|
if (!page_poison(page))
|
|
return;
|
|
|
|
addr = kmap_atomic(page);
|
|
check_poison_mem(addr, PAGE_SIZE);
|
|
mark_addr_rdwrite(addr);
|
|
clear_page_poison(page);
|
|
kunmap_atomic(addr);
|
|
}
|
|
|
|
static void unpoison_pages(struct page *page, int n)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < n; i++)
|
|
unpoison_page(page + i);
|
|
}
|
|
|
|
void __kernel_map_pages(struct page *page, int numpages, int enable)
|
|
{
|
|
if (!page_poisoning_enabled)
|
|
return;
|
|
|
|
if (enable)
|
|
unpoison_pages(page, numpages);
|
|
else
|
|
poison_pages(page, numpages);
|
|
}
|