drm/radeon/kms/atom: fix handling of FB scratch indices
FB scratch indices are dword indices, but we were treating
them as byte indices. As such, we were getting the wrong
FB scratch data for non-0 indices. Fix the indices and
guard the indexing against indices larger than the scratch
allocation.
Fixes memory corruption on some boards if data was written
past the end of the FB scratch array.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reported-by: Dave Airlie <airlied@redhat.com>
Tested-by: Dave Airlie <airlied@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/atom.c b/drivers/gpu/drm/radeon/atom.c
index e88c644..14cc88a 100644
--- a/drivers/gpu/drm/radeon/atom.c
+++ b/drivers/gpu/drm/radeon/atom.c
@@ -277,7 +277,12 @@
case ATOM_ARG_FB:
idx = U8(*ptr);
(*ptr)++;
- val = gctx->scratch[((gctx->fb_base + idx) / 4)];
+ if ((gctx->fb_base + (idx * 4)) > gctx->scratch_size_bytes) {
+ DRM_ERROR("ATOM: fb read beyond scratch region: %d vs. %d\n",
+ gctx->fb_base + (idx * 4), gctx->scratch_size_bytes);
+ val = 0;
+ } else
+ val = gctx->scratch[(gctx->fb_base / 4) + idx];
if (print)
DEBUG("FB[0x%02X]", idx);
break;
@@ -531,7 +536,11 @@
case ATOM_ARG_FB:
idx = U8(*ptr);
(*ptr)++;
- gctx->scratch[((gctx->fb_base + idx) / 4)] = val;
+ if ((gctx->fb_base + (idx * 4)) > gctx->scratch_size_bytes) {
+ DRM_ERROR("ATOM: fb write beyond scratch region: %d vs. %d\n",
+ gctx->fb_base + (idx * 4), gctx->scratch_size_bytes);
+ } else
+ gctx->scratch[(gctx->fb_base / 4) + idx] = val;
DEBUG("FB[0x%02X]", idx);
break;
case ATOM_ARG_PLL:
@@ -1370,11 +1379,13 @@
usage_bytes = firmware_usage->asFirmwareVramReserveInfo[0].usFirmwareUseInKb * 1024;
}
+ ctx->scratch_size_bytes = 0;
if (usage_bytes == 0)
usage_bytes = 20 * 1024;
/* allocate some scratch memory */
ctx->scratch = kzalloc(usage_bytes, GFP_KERNEL);
if (!ctx->scratch)
return -ENOMEM;
+ ctx->scratch_size_bytes = usage_bytes;
return 0;
}
diff --git a/drivers/gpu/drm/radeon/atom.h b/drivers/gpu/drm/radeon/atom.h
index a589a55..93cfe20 100644
--- a/drivers/gpu/drm/radeon/atom.h
+++ b/drivers/gpu/drm/radeon/atom.h
@@ -137,6 +137,7 @@
int cs_equal, cs_above;
int io_mode;
uint32_t *scratch;
+ int scratch_size_bytes;
};
extern int atom_debug;