[PATCH] x86_64: Fix off by one in bad_addr checking in find_e820_area
From: Robert Hentosh <robert_hentosh@dell.com>
Actually, we just stumbled on a different bug found in find_e820_area() in
e820.c. The following code does not handle the edge condition correctly:
while (bad_addr(&addr, size) && addr+size < ei->addr + ei->size)
;
last = addr + size;
if ( last > ei->addr + ei->size )
continue;
The second statement in the while loop needs to be a <= b so that it is the
logical negavite of the if (a > b) outside it. It needs to read:
while (bad_addr(&addr, size) && addr+size <= ei->addr + ei->size)
;
In the case that failed bad_addr was returning an address that is exactly size
bellow the end of the e820 range.
AK: Again together with the earlier avoid edma fix this fixes
boot on a Dell PE6850/16GB
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/kernel/e820.c b/arch/x86_64/kernel/e820.c
index 222b5b4..1ef6028 100644
--- a/arch/x86_64/kernel/e820.c
+++ b/arch/x86_64/kernel/e820.c
@@ -149,7 +149,7 @@
addr = start;
if (addr > ei->addr + ei->size)
continue;
- while (bad_addr(&addr, size) && addr+size < ei->addr + ei->size)
+ while (bad_addr(&addr, size) && addr+size <= ei->addr+ei->size)
;
last = addr + size;
if (last > ei->addr + ei->size)