From 33afe065b66f226ee5f90ab24ff55799c896e381 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu, 8 Feb 2018 08:51:51 +0000
Subject: [PATCH] drm/i915: Avoid truncation before clamping userspace's priority value
Git-commit: 33afe065b66f226ee5f90ab24ff55799c896e381
Patch-mainline: v4.16-rc2
References: FATE#322643 bsc#1055900
No-fix: 11a18f631959fd1ca10856c836a827683536770c

Userspace provides a 64b value for the priority, we need to be careful
to preserve the full range before validation to prevent truncation (and
letting an illegal value pass).

Reported-by: Antonio Argenziano <antonio.argenziano@intel.com>
Fixes: ac14fbd460d0 ("drm/i915/scheduler: Support user-defined priorities")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Antonio Argenziano <antonio.argenziano@intel.com>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180208085151.11480-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
(cherry picked from commit 11a18f631959fd1ca10856c836a827683536770c)

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/i915_gem_context.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -803,7 +803,7 @@ int i915_gem_context_setparam_ioctl(stru
 
 	case I915_CONTEXT_PARAM_PRIORITY:
 		{
-			int priority = args->value;
+			s64 priority = args->value;
 
 			if (args->size)
 				ret = -EINVAL;