From: kernel test robot <lkp@intel.com>
To: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Cc: oe-kbuild-all@lists.linux.dev, linux-kernel@vger.kernel.org,
"Christian König " <christian.koenig@amd.com>
Subject: drivers/dma-buf/dma-fence.c:1112:51: sparse: sparse: incorrect type in return expression (different address spaces)
Date: Sat, 17 Jan 2026 01:22:06 +0800 [thread overview]
Message-ID: <202601170112.FVBMyjX0-lkp@intel.com> (raw)
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 983d014aafb14ee5e4915465bf8948e8f3a723b5
commit: 506aa8b02a8d6898c64cc095d233fbae1cef8b8a dma-fence: Add safe access helpers and document the rules
date: 7 months ago
config: i386-randconfig-063-20260116 (https://download.01.org/0day-ci/archive/20260117/202601170112.FVBMyjX0-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260117/202601170112.FVBMyjX0-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202601170112.FVBMyjX0-lkp@intel.com/
sparse warnings: (new ones prefixed by >>)
>> drivers/dma-buf/dma-fence.c:1112:51: sparse: sparse: incorrect type in return expression (different address spaces) @@ expected char const [noderef] __rcu * @@ got char const * @@
drivers/dma-buf/dma-fence.c:1112:51: sparse: expected char const [noderef] __rcu *
drivers/dma-buf/dma-fence.c:1112:51: sparse: got char const *
drivers/dma-buf/dma-fence.c:1114:24: sparse: sparse: incorrect type in return expression (different address spaces) @@ expected char const [noderef] __rcu * @@ got char * @@
drivers/dma-buf/dma-fence.c:1114:24: sparse: expected char const [noderef] __rcu *
drivers/dma-buf/dma-fence.c:1114:24: sparse: got char *
drivers/dma-buf/dma-fence.c:1144:51: sparse: sparse: incorrect type in return expression (different address spaces) @@ expected char const [noderef] __rcu * @@ got char const * @@
drivers/dma-buf/dma-fence.c:1144:51: sparse: expected char const [noderef] __rcu *
drivers/dma-buf/dma-fence.c:1144:51: sparse: got char const *
drivers/dma-buf/dma-fence.c:1146:24: sparse: sparse: incorrect type in return expression (different address spaces) @@ expected char const [noderef] __rcu * @@ got char * @@
drivers/dma-buf/dma-fence.c:1146:24: sparse: expected char const [noderef] __rcu *
drivers/dma-buf/dma-fence.c:1146:24: sparse: got char *
drivers/dma-buf/dma-fence.c: note: in included file (through include/trace/trace_events.h, include/trace/define_trace.h, include/trace/events/dma_fence.h):
include/trace/events/dma_fence.h:12:1: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected char const *str @@ got char const [noderef] __rcu * @@
include/trace/events/dma_fence.h:12:1: sparse: expected char const *str
include/trace/events/dma_fence.h:12:1: sparse: got char const [noderef] __rcu *
include/trace/events/dma_fence.h:12:1: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected char const *str @@ got char const [noderef] __rcu * @@
include/trace/events/dma_fence.h:12:1: sparse: expected char const *str
include/trace/events/dma_fence.h:12:1: sparse: got char const [noderef] __rcu *
include/trace/events/dma_fence.h:12:1: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected char const *str @@ got char const [noderef] __rcu * @@
include/trace/events/dma_fence.h:12:1: sparse: expected char const *str
include/trace/events/dma_fence.h:12:1: sparse: got char const [noderef] __rcu *
include/trace/events/dma_fence.h:12:1: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected void const *driver_ptr_ @@ got char const [noderef] __rcu * @@
include/trace/events/dma_fence.h:12:1: sparse: expected void const *driver_ptr_
include/trace/events/dma_fence.h:12:1: sparse: got char const [noderef] __rcu *
include/trace/events/dma_fence.h:12:1: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected char const *str @@ got char const [noderef] __rcu * @@
include/trace/events/dma_fence.h:12:1: sparse: expected char const *str
include/trace/events/dma_fence.h:12:1: sparse: got char const [noderef] __rcu *
include/trace/events/dma_fence.h:12:1: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected char const *str @@ got char const [noderef] __rcu * @@
include/trace/events/dma_fence.h:12:1: sparse: expected char const *str
include/trace/events/dma_fence.h:12:1: sparse: got char const [noderef] __rcu *
include/trace/events/dma_fence.h:12:1: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected char const *str @@ got char const [noderef] __rcu * @@
include/trace/events/dma_fence.h:12:1: sparse: expected char const *str
include/trace/events/dma_fence.h:12:1: sparse: got char const [noderef] __rcu *
include/trace/events/dma_fence.h:12:1: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected void const *timeline_ptr_ @@ got char const [noderef] __rcu * @@
include/trace/events/dma_fence.h:12:1: sparse: expected void const *timeline_ptr_
include/trace/events/dma_fence.h:12:1: sparse: got char const [noderef] __rcu *
include/trace/events/dma_fence.h:12:1: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected char const *str @@ got char const [noderef] __rcu * @@
include/trace/events/dma_fence.h:12:1: sparse: expected char const *str
include/trace/events/dma_fence.h:12:1: sparse: got char const [noderef] __rcu *
include/trace/events/dma_fence.h:12:1: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected char const *str @@ got char const [noderef] __rcu * @@
include/trace/events/dma_fence.h:12:1: sparse: expected char const *str
include/trace/events/dma_fence.h:12:1: sparse: got char const [noderef] __rcu *
include/trace/events/dma_fence.h:12:1: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected char const *str @@ got char const [noderef] __rcu * @@
include/trace/events/dma_fence.h:12:1: sparse: expected char const *str
include/trace/events/dma_fence.h:12:1: sparse: got char const [noderef] __rcu *
include/trace/events/dma_fence.h:12:1: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected void const *driver_ptr_ @@ got char const [noderef] __rcu * @@
include/trace/events/dma_fence.h:12:1: sparse: expected void const *driver_ptr_
include/trace/events/dma_fence.h:12:1: sparse: got char const [noderef] __rcu *
include/trace/events/dma_fence.h:12:1: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected char const *str @@ got char const [noderef] __rcu * @@
include/trace/events/dma_fence.h:12:1: sparse: expected char const *str
include/trace/events/dma_fence.h:12:1: sparse: got char const [noderef] __rcu *
include/trace/events/dma_fence.h:12:1: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected char const *str @@ got char const [noderef] __rcu * @@
include/trace/events/dma_fence.h:12:1: sparse: expected char const *str
include/trace/events/dma_fence.h:12:1: sparse: got char const [noderef] __rcu *
include/trace/events/dma_fence.h:12:1: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected char const *str @@ got char const [noderef] __rcu * @@
include/trace/events/dma_fence.h:12:1: sparse: expected char const *str
include/trace/events/dma_fence.h:12:1: sparse: got char const [noderef] __rcu *
include/trace/events/dma_fence.h:12:1: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected void const *timeline_ptr_ @@ got char const [noderef] __rcu * @@
include/trace/events/dma_fence.h:12:1: sparse: expected void const *timeline_ptr_
include/trace/events/dma_fence.h:12:1: sparse: got char const [noderef] __rcu *
vim +1112 drivers/dma-buf/dma-fence.c
1085
1086 /**
1087 * dma_fence_driver_name - Access the driver name
1088 * @fence: the fence to query
1089 *
1090 * Returns a driver name backing the dma-fence implementation.
1091 *
1092 * IMPORTANT CONSIDERATION:
1093 * Dma-fence contract stipulates that access to driver provided data (data not
1094 * directly embedded into the object itself), such as the &dma_fence.lock and
1095 * memory potentially accessed by the &dma_fence.ops functions, is forbidden
1096 * after the fence has been signalled. Drivers are allowed to free that data,
1097 * and some do.
1098 *
1099 * To allow safe access drivers are mandated to guarantee a RCU grace period
1100 * between signalling the fence and freeing said data.
1101 *
1102 * As such access to the driver name is only valid inside a RCU locked section.
1103 * The pointer MUST be both queried and USED ONLY WITHIN a SINGLE block guarded
1104 * by the &rcu_read_lock and &rcu_read_unlock pair.
1105 */
1106 const char __rcu *dma_fence_driver_name(struct dma_fence *fence)
1107 {
1108 RCU_LOCKDEP_WARN(!rcu_read_lock_held(),
1109 "RCU protection is required for safe access to returned string");
1110
1111 if (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
> 1112 return fence->ops->get_driver_name(fence);
1113 else
1114 return "detached-driver";
1115 }
1116 EXPORT_SYMBOL(dma_fence_driver_name);
1117
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
reply other threads:[~2026-01-16 17:22 UTC|newest]
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