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Commit 958a6f8c authored by David Miller's avatar David Miller Committed by Dave Airlie
Browse files

drm: radeon: Fix unaligned access in r300_scratch(). 



In compat mode, the cmdbuf->buf 64-bit address cookie can
potentially be only 32-bit aligned.  Dereferencing this as
64-bit causes expensive unaligned traps on platforms like
sparc64.

Use get_unaligned() to fix.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
parent f1a2a9b6

drivers/gpu/drm/radeon/r300_cmdbuf.c

+5 −1
Original line number Diff line number Diff line
@@ -37,6 +37,8 @@ 
#include "radeon_drv.h"

#include "r300_reg.h"



#include <asm/unaligned.h>



#define R300_SIMULTANEOUS_CLIPRECTS		4



/* Values for R300_RE_CLIPRECT_CNTL depending on the number of cliprects
@@ -917,6 +919,7 @@ static int r300_scratch(drm_radeon_private_t *dev_priv, 
{

	u32 *ref_age_base;

	u32 i, buf_idx, h_pending;

	u64 ptr_addr;

	RING_LOCALS;



	if (cmdbuf->bufsz <
@@ -930,7 +933,8 @@ static int r300_scratch(drm_radeon_private_t *dev_priv, 


	dev_priv->scratch_ages[header.scratch.reg]++;



	ref_age_base =  (u32 *)(unsigned long)*((uint64_t *)cmdbuf->buf);

	ptr_addr = get_unaligned((u64 *)cmdbuf->buf);

	ref_age_base = (u32 *)(unsigned long)ptr_addr;



	cmdbuf->buf += sizeof(u64);

	cmdbuf->bufsz -= sizeof(u64);