tree c69a7dc3a48b9bc9dbb19f08fd48bc0275bbf792
parent 0d01532451710110a93891ae152d1dd1ee006ccf
author Robert Hentosh <robert_hentosh@dell.com> 1149022080 +0200
committer Linus Torvalds <torvalds@g5.osdl.org> 1149046266 -0700

[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>