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authorYinghai Lu <yinghai@kernel.org>2009-07-01 12:32:18 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-07-02 12:11:12 -0700
commit7c5371c403abb29f01bc6cff6c5096abdf2dc524 (patch)
tree8c087cac6358dfefa14e6819c4b4dbb4c7326af4 /arch/x86/kernel/e820.c
parent43644679a1e80f53e6e0155ab75b1093ba3c0365 (diff)
downloadlinux-7c5371c403abb29f01bc6cff6c5096abdf2dc524.tar.gz
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: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/kernel/e820.c')
-rw-r--r--arch/x86/kernel/e820.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 7271fa33d791..c4ca89d9aaf4 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -1383,6 +1383,8 @@ static unsigned long ram_alignment(resource_size_t pos)
return 32*1024*1024;
}
+#define MAX_RESOURCE_SIZE ((resource_size_t)-1)
+
void __init e820_reserve_resources_late(void)
{
int i;
@@ -1400,17 +1402,19 @@ void __init e820_reserve_resources_late(void)
* avoid stolen RAM:
*/
for (i = 0; i < e820.nr_map; i++) {
- struct e820entry *entry = &e820_saved.map[i];
- resource_size_t start, end;
+ struct e820entry *entry = &e820.map[i];
+ u64 start, end;
if (entry->type != E820_RAM)
continue;
start = entry->addr + entry->size;
- end = round_up(start, ram_alignment(start));
- if (start == end)
+ end = round_up(start, ram_alignment(start)) - 1;
+ if (end > MAX_RESOURCE_SIZE)
+ end = MAX_RESOURCE_SIZE;
+ if (start >= end)
continue;
- reserve_region_with_split(&iomem_resource, start,
- end - 1, "RAM buffer");
+ reserve_region_with_split(&iomem_resource, start, end,
+ "RAM buffer");
}
}