From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 22 May 2018 13:10:18 +0100
Subject: drm/i915/query: nospec expects no more than an unsigned long
Git-commit: 65b3bdc807ac7bd83f5b27bc2c29a3c631eed7dd
Patch-mainline: v4.17
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
nospec quite reasonably asserts that it will never be used with an index
larger than unsigned long (that being the largest possibly index into an
C array). However, our ubi uses the convention of u64 for any large
integer, running afoul of the assertion on 32b. Reduce our index to an
unsigned long, checking for type overflow first.
drivers/gpu/drm/i915/i915_query.c: In function 'i915_query_ioctl':
include/linux/compiler.h:339:38: error: call to '__compiletime_assert_119' declared with attribute error: BUILD_BUG_ON failed: sizeof(_s) > sizeof(long)
Reported-by: kbuild-all@01.org
Fixes: 84b510e22da7 ("drm/i915/query: Protect tainted function pointer lookup")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180522121018.15199-1-chris@chris-wilson.co.uk
(cherry picked from commit a33b1dc8a732144e11cb4bf067d24ba51e6b8ab0)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/i915/i915_query.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/i915/i915_query.c
+++ b/drivers/gpu/drm/i915/i915_query.c
@@ -102,7 +102,7 @@ int i915_query_ioctl(struct drm_device *
for (i = 0; i < args->num_items; i++, user_item_ptr++) {
struct drm_i915_query_item item;
- u64 func_idx;
+ unsigned long func_idx;
int ret;
if (copy_from_user(&item, user_item_ptr, sizeof(item)))
@@ -111,6 +111,9 @@ int i915_query_ioctl(struct drm_device *
if (item.query_id == 0)
return -EINVAL;
+ if (overflows_type(item.query_id - 1, unsigned long))
+ return -EINVAL;
+
func_idx = item.query_id - 1;
ret = -EINVAL;