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Commit 058c9685 authored by Matt Wagantall's avatar Matt Wagantall
Browse files

ARM: Improve vmalloc address checking in show_data() 



There is an unhandled corner case with the current check
which has recently been hit. The nbytes argument may be
large enough for the range being dumped to cross a
boundary between page-table mappings, and dump addresses
which are vmalloc'd in the neighboring mapping.

Check every address being dumped to see if its vmalloc'd,
not just the address passed to show_data().

Change-Id: I255b093808177321f5202dcacea337ee333bfc63
Signed-off-by: default avatarMatt Wagantall <mattw@codeaurora.org>
parent 11e8434e

arch/arm/kernel/process.c

+9 −6
Original line number Diff line number Diff line
@@ -321,12 +321,10 @@ static void show_data(unsigned long addr, int nbytes, const char *name) 
	u32	*p;



	/*

	 * don't attempt to dump non-kernel addresses, values that are probably

	 * just small negative numbers, or vmalloc addresses that may point to

	 * memory-mapped peripherals

	 * don't attempt to dump non-kernel addresses or

	 * values that are probably just small negative numbers

	 */

	if (addr < PAGE_OFFSET || addr > -256UL ||

	    is_vmalloc_addr((void *)addr))

	if (addr < PAGE_OFFSET || addr > -256UL)

		return;



	printk("\n%s: %#lx:\n", name, addr);
@@ -348,7 +346,12 @@ static void show_data(unsigned long addr, int nbytes, const char *name) 
		printk("%04lx ", (unsigned long)p & 0xffff);

		for (j = 0; j < 8; j++) {

			u32	data;

			if (probe_kernel_address(p, data)) {

			/*

			 * vmalloc addresses may point to

			 * memory-mapped peripherals

			 */

			if (is_vmalloc_addr(p) ||

			    probe_kernel_address(p, data)) {

				printk(" ********");

			} else {

				printk(" %08x", data);