linux-kernel - [PATCH 2/2] drm/i915/gvt: fix compilation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 21 Oct 2016 17:25:50 +0200
From:   Arnd Bergmann <arnd@...db.de>
To:     Daniel Vetter <daniel.vetter@...el.com>,
        Jani Nikula <jani.nikula@...ux.intel.com>
Cc:     Zhi Wang <zhi.a.wang@...el.com>,
        Zhenyu Wang <zhenyuw@...ux.intel.com>,
        Arnd Bergmann <arnd@...db.de>, David Airlie <airlied@...ux.ie>,
        Chris Wilson <chris@...is-wilson.co.uk>,
        igvt-g-dev@...ts.01.org, intel-gfx@...ts.freedesktop.org,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: [PATCH 2/2] drm/i915/gvt: fix compilation

Two functions in the newly added gvt render code are obviously
broken, as they reference a variable without initialization and
don't reference another variable at all:

drivers/gpu/drm/i915/gvt/render.c: In function ‘intel_gvt_load_render_mmio’:
drivers/gpu/drm/i915/gvt/render.c:148:13: error: ‘offset.reg’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/gpu/drm/i915/gvt/render.c: In function ‘intel_gvt_restore_render_mmio’:
drivers/gpu/drm/i915/gvt/render.c:185:13: error: ‘offset.reg’ may be used uninitialized in this function [-Werror=maybe-uninitialized]

This is probably not a correct fix, but it gets us a clean build
by removing the unused arrays and initializing the offset variable
to something that potentially might be correct.

Fixes: 178657139307 ("drm/i915/gvt: vGPU context switch")
Signed-off-by: Arnd Bergmann <arnd@...db.de>
---
 drivers/gpu/drm/i915/gvt/render.c | 25 +++----------------------
 1 file changed, 3 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/render.c b/drivers/gpu/drm/i915/gvt/render.c
index feebb65ba641..79e112288065 100644
--- a/drivers/gpu/drm/i915/gvt/render.c
+++ b/drivers/gpu/drm/i915/gvt/render.c
@@ -147,29 +147,20 @@ static void load_mocs(struct intel_vgpu *vgpu, int ring_id)
 {
 	struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
 	i915_reg_t offset, l3_offset;
-	u32 regs[] = {
-		[RCS] = 0xc800,
-		[VCS] = 0xc900,
-		[VCS2] = 0xca00,
-		[BCS] = 0xcc00,
-		[VECS] = 0xcb00,
-	};
 	int i;
 
-	if (WARN_ON(ring_id >= ARRAY_SIZE(regs)))
-		return;
-
 	if (!IS_SKYLAKE(dev_priv))
 		return;
 
 	for (i = 0; i < 64; i++) {
+		offset.reg = i * 4;
 		gen9_render_mocs[ring_id][i] = I915_READ(offset);
 		I915_WRITE(offset, vgpu_vreg(vgpu, offset));
 		POSTING_READ(offset);
-		offset.reg += 4;
 	}
 
 	if (ring_id == RCS) {
+		offset.reg = 64 * 4;
 		l3_offset.reg = 0xb020;
 		for (i = 0; i < 32; i++) {
 			gen9_render_mocs_L3[i] = I915_READ(l3_offset);
@@ -184,26 +175,16 @@ static void restore_mocs(struct intel_vgpu *vgpu, int ring_id)
 {
 	struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
 	i915_reg_t offset, l3_offset;
-	u32 regs[] = {
-		[RCS] = 0xc800,
-		[VCS] = 0xc900,
-		[VCS2] = 0xca00,
-		[BCS] = 0xcc00,
-		[VECS] = 0xcb00,
-	};
 	int i;
 
-	if (WARN_ON(ring_id >= ARRAY_SIZE(regs)))
-		return;
-
 	if (!IS_SKYLAKE(dev_priv))
 		return;
 
 	for (i = 0; i < 64; i++) {
+		offset.reg = i * 4;
 		vgpu_vreg(vgpu, offset) = I915_READ(offset);
 		I915_WRITE(offset, gen9_render_mocs[ring_id][i]);
 		POSTING_READ(offset);
-		offset.reg += 4;
 	}
 
 	if (ring_id == RCS) {
-- 
2.9.0