From 5ad16855bdc2dfbd9a1e52dafc2e59cf2826b8fe Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Mon, 11 Nov 2019 08:13:24 -0800 Subject: [PATCH] drm/i915/cmdparser: Fix jump whitelist clearing commit ea0b163b13ffc52818c079adb00d55e227a6da6f upstream. When a jump_whitelist bitmap is reused, it needs to be cleared. Currently this is done with memset() and the size calculation assumes bitmaps are made of 32-bit words, not longs. So on 64-bit architectures, only the first half of the bitmap is cleared. If some whitelist bits are carried over between successive batches submitted on the same context, this will presumably allow embedding the rogue instructions that we're trying to reject. Use bitmap_zero() instead, which gets the calculation right. Fixes: f8c08d8faee5 ("drm/i915/cmdparser: Add support for backward jumps") Signed-off-by: Ben Hutchings Signed-off-by: Jon Bloomfield Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/i915_cmd_parser.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c index 7f1e2c5e113f..1e104518192d 100644 --- a/drivers/gpu/drm/i915/i915_cmd_parser.c +++ b/drivers/gpu/drm/i915/i915_cmd_parser.c @@ -1374,7 +1374,7 @@ static void init_whitelist(struct i915_gem_context *ctx, u32 batch_len) return; if (batch_cmds <= ctx->jump_whitelist_cmds) { - memset(ctx->jump_whitelist, 0, exact_size * sizeof(u32)); + bitmap_zero(ctx->jump_whitelist, batch_cmds); return; } @@ -1394,8 +1394,7 @@ again: } DRM_DEBUG("CMD: Failed to extend whitelist. BB_START may be disallowed\n"); - memset(ctx->jump_whitelist, 0, - BITS_TO_LONGS(ctx->jump_whitelist_cmds) * sizeof(u32)); + bitmap_zero(ctx->jump_whitelist, ctx->jump_whitelist_cmds); return; }