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* [PATCH] amdkfd: use sizeof(long) granularity for the pasid bitmask
@ 2014-12-03 14:26 Sasha Levin
  2014-12-04 12:21 ` Oded Gabbay
  0 siblings, 1 reply; 2+ messages in thread
From: Sasha Levin @ 2014-12-03 14:26 UTC (permalink / raw)
  To: oded.gabbay
  Cc: airlied, alexander.deucher, j.glisse, linux-kernel, dri-devel,
	John.Bridgman, Andrew.Lewycky, joro, Sasha Levin

All the bit operations (such as find_first_zero_bit()) read sizeof(long) bytes
at a time. If we allocated less than sizeof(long) bytes for the bitmask we
would be accessing invalid memory when working with the bitmask.

Change the allocator to allocate sizeof(long) multiples for the bitmask.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
---
 drivers/gpu/drm/amd/amdkfd/kfd_pasid.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_pasid.c b/drivers/gpu/drm/amd/amdkfd/kfd_pasid.c
index 2458ab7..71699ad 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_pasid.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_pasid.c
@@ -32,8 +32,7 @@ int kfd_pasid_init(void)
 {
 	pasid_limit = max_num_of_processes;
 
-	pasid_bitmap = kzalloc(DIV_ROUND_UP(pasid_limit, BITS_PER_BYTE),
-				GFP_KERNEL);
+	pasid_bitmap = kzalloc(BITS_TO_LONGS(pasid_limit), GFP_KERNEL);
 	if (!pasid_bitmap)
 		return -ENOMEM;
 
-- 
2.1.0


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2014-12-03 14:26 [PATCH] amdkfd: use sizeof(long) granularity for the pasid bitmask Sasha Levin
2014-12-04 12:21 ` Oded Gabbay

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