pfn_pdx_hole_setup is meant to skip the first MAX_ORDER bits, but
actually it only skips the first MAX_ORDER-1 bits. The issue was
probably introduced by bdb5439c3f, when changing to loop to start from
MAX_ORDER-1 an adjustment by 1 was needed in the call to find_next_bit()
but not done.
Fix the issue by passing j+1 and i+1 to find_next_zero_bit and
find_next_bit. Also add a check for i >= BITS_PER_LONG because
find_{,next_}zero_bit() on x86 assume their last argument to be less
than their middle one.
Signed-off-by: Stefano Stabellini <[email protected]>
Signed-off-by: Jan Beulich <[email protected]>
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
---
xen/common/pdx.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/xen/common/pdx.c b/xen/common/pdx.c
index 50c21b6..bb7e437 100644
--- a/xen/common/pdx.c
+++ b/xen/common/pdx.c
@@ -83,8 +83,10 @@ void __init pfn_pdx_hole_setup(unsigned long mask)
*/
for ( j = MAX_ORDER-1; ; )
{
- i = find_next_zero_bit(&mask, BITS_PER_LONG, j);
- j = find_next_bit(&mask, BITS_PER_LONG, i);
+ i = find_next_zero_bit(&mask, BITS_PER_LONG, j + 1);
+ if ( i >= BITS_PER_LONG )
+ break;
+ j = find_next_bit(&mask, BITS_PER_LONG, i + 1);
if ( j >= BITS_PER_LONG )
break;
if ( j - i > hole_shift )
--
1.9.1
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