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Commit d3ad4ca7 authored by qctecmdr's avatar qctecmdr Committed by Gerrit - the friendly Code Review server
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Merge "debug-pagealloc: Panic on pagealloc corruption"

parents fdf561d7 8777aa80

include/linux/bug.h

+5 −0
Original line number Diff line number Diff line
@@ -81,4 +81,9 @@ static inline __must_check bool check_data_corruption(bool v) { return v; } 
		corruption;						 \

	}))



#ifdef CONFIG_PANIC_ON_DATA_CORRUPTION

#define PANIC_CORRUPTION 1

#else

#define PANIC_CORRUPTION 0

#endif  /* CONFIG_PANIC_ON_DATA_CORRUPTION */

#endif	/* _LINUX_BUG_H */

lib/Kconfig.debug

+9 −0
Original line number Diff line number Diff line
@@ -2134,6 +2134,15 @@ config BUG_ON_DATA_CORRUPTION 


	  If unsure, say N.



config PANIC_ON_DATA_CORRUPTION

	bool "Cause a Kernel Panic When Data Corruption is detected"

	help

	 Select this option to upgrade warnings for potentially

	 recoverable data corruption scenarios to system-halting panics,

	 for easier detection and debug.

	 If we do not panic immediately after corruptions have been detected,

	 the problem context is lost in the ensuing system mayhem.



source "samples/Kconfig"



source "lib/Kconfig.kgdb"

mm/page_poison.c

+8 −4
Original line number Diff line number Diff line
@@ -64,7 +64,8 @@ static bool single_bit_flip(unsigned char a, unsigned char b) 
	return error && !(error & (error - 1));

}



static void check_poison_mem(unsigned char *mem, size_t bytes)

static void check_poison_mem(struct page *page,

			     unsigned char *mem, size_t bytes)

{

	static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 10);

	unsigned char *start;
@@ -85,12 +86,15 @@ static void check_poison_mem(unsigned char *mem, size_t bytes) 
	if (!__ratelimit(&ratelimit))

		return;

	else if (start == end && single_bit_flip(*start, PAGE_POISON))

		pr_err("pagealloc: single bit error\n");

		pr_err("pagealloc: single bit error on page with phys start 0x%lx\n",

			(unsigned long)page_to_phys(page));

	else

		pr_err("pagealloc: memory corruption\n");

		pr_err("pagealloc: memory corruption on page with phys start 0x%lx\n",

			(unsigned long)page_to_phys(page));



	print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1, start,

			end - start + 1, 1);

	BUG_ON(PANIC_CORRUPTION);

	dump_stack();

}
@@ -104,7 +108,7 @@ static void unpoison_page(struct page *page) 
	 * that is freed to buddy. Thus no extra check is done to

	 * see if a page was poisoned.

	 */

	check_poison_mem(addr, PAGE_SIZE);

	check_poison_mem(page, addr, PAGE_SIZE);

	kunmap_atomic(addr);

}