From: Ben Hutchings Date: Mon, 11 Nov 2019 16:13:24 +0000 (-0800) Subject: drm/i915/cmdparser: Fix jump whitelist clearing X-Git-Tag: v5.3.11~19 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0a4f236d3ad245824e8571d15338c38eea71fae0;p=thirdparty%2Fkernel%2Fstable.git 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 --- diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c index efb6d0727eeac..a412e346b29ca 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; }