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Commit 7c5371c4 authored by Yinghai Lu's avatar Yinghai Lu Committed by Linus Torvalds
Browse files

x86: add boundary check for 32bit res before expand e820 resource to alignment 



fix hang with HIGHMEM_64G and 32bit resource.  According to hpa and
Linus, use (resource_size_t)-1 to fend off big ranges.

Analyzed by hpa

Reported-and-tested-by: default avatarMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 43644679

arch/x86/kernel/e820.c

+10 −6
Original line number Original line Diff line number Diff line
@@ -1383,6 +1383,8 @@ static unsigned long ram_alignment(resource_size_t pos) 
	return 32*1024*1024;

	return 32*1024*1024;

}

}





#define MAX_RESOURCE_SIZE ((resource_size_t)-1)



void __init e820_reserve_resources_late(void)

void __init e820_reserve_resources_late(void)

{

{

	int i;

	int i;
@@ -1400,17 +1402,19 @@ void __init e820_reserve_resources_late(void) 
	 * avoid stolen RAM:

	 * avoid stolen RAM:

	 */

	 */

	for (i = 0; i < e820.nr_map; i++) {

	for (i = 0; i < e820.nr_map; i++) {

		struct e820entry *entry = &e820_saved.map[i];

		struct e820entry *entry = &e820.map[i];

		resource_size_t start, end;

		u64 start, end;





		if (entry->type != E820_RAM)

		if (entry->type != E820_RAM)

			continue;

			continue;

		start = entry->addr + entry->size;

		start = entry->addr + entry->size;

		end = round_up(start, ram_alignment(start));

		end = round_up(start, ram_alignment(start)) - 1;

		if (start == end)

		if (end > MAX_RESOURCE_SIZE)

			end = MAX_RESOURCE_SIZE;

		if (start >= end)

			continue;

			continue;

		reserve_region_with_split(&iomem_resource, start,

		reserve_region_with_split(&iomem_resource, start, end,

						  end - 1, "RAM buffer");

					  "RAM buffer");

	}

	}

}

}