kernel/trace/trace_events_user.c:593:31: sparse: sparse: incorrect type in assignment (different address spaces)

kernel/trace/trace_events_user.c:593:31: sparse: sparse: incorrect type in assignment (different address spaces)

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   ae085d7f9365de7da27ab5c0d16b12d51ea7fca9
commit: 0279400ad38d858ed68f5d787385f6122d4170b2 user_events: Optimize writing events by only copying data once
date:   6 weeks ago
config: i386-randconfig-s001-20220328 (https://download.01.org/0day-ci/archive/20220328/202203281937.Po855SGa-lkp@intel.com/config)
compiler: gcc-9 (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.4-dirty
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0279400ad38d858ed68f5d787385f6122d4170b2
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout 0279400ad38d858ed68f5d787385f6122d4170b2
        # save the config file to linux build tree
        mkdir build_dir
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=i386 SHELL=/bin/bash drivers/acpi/apei/ drivers/gpu/drm/ kernel/trace/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


sparse warnings: (new ones prefixed by >>)
   kernel/trace/trace_events_user.c:409:38: sparse: sparse: Using plain integer as NULL pointer
   kernel/trace/trace_events_user.c:430:40: sparse: sparse: Using plain integer as NULL pointer
>> kernel/trace/trace_events_user.c:593:31: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected void *[assigned] udata @@     got void [noderef] __user * @@
   kernel/trace/trace_events_user.c:593:31: sparse:     expected void *[assigned] udata
   kernel/trace/trace_events_user.c:593:31: sparse:     got void [noderef] __user *
   kernel/trace/trace_events_user.c:1064:16: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/trace/trace_events_user.c:1064:16: sparse:    void [noderef] __rcu *
   kernel/trace/trace_events_user.c:1064:16: sparse:    void *
   kernel/trace/trace_events_user.c:1122:13: sparse: sparse: cast removes address space '__user' of expression
   kernel/trace/trace_events_user.c:1122:13: sparse: sparse: incorrect type in argument 2 (different address spaces) @@     expected void [noderef] __user *buf @@     got char * @@
   kernel/trace/trace_events_user.c:1122:13: sparse:     expected void [noderef] __user *buf
   kernel/trace/trace_events_user.c:1122:13: sparse:     got char *
   kernel/trace/trace_events_user.c:1138:16: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/trace/trace_events_user.c:1138:16: sparse:    void [noderef] __rcu *
   kernel/trace/trace_events_user.c:1138:16: sparse:    void *
   kernel/trace/trace_events_user.c:1165:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
   kernel/trace/trace_events_user.c:1165:9: sparse:    void [noderef] __rcu *
   kernel/trace/trace_events_user.c:1165:9: sparse:    void *

vim +593 kernel/trace/trace_events_user.c

   571	
   572	#ifdef CONFIG_PERF_EVENTS
   573	static void user_event_bpf(struct user_event *user, struct iov_iter *i)
   574	{
   575		struct user_bpf_context context;
   576		struct user_bpf_iter bpf_i;
   577		char fast_data[MAX_STACK_BPF_DATA];
   578		void *temp = NULL;
   579	
   580		if ((user->flags & FLAG_BPF_ITER) && iter_is_iovec(i)) {
   581			/* Raw iterator */
   582			context.data_type = USER_BPF_DATA_ITER;
   583			context.data_len = i->count;
   584			context.iter = &bpf_i;
   585	
   586			bpf_i.iov_offset = i->iov_offset;
   587			bpf_i.iov = i->iov;
   588			bpf_i.nr_segs = i->nr_segs;
   589		} else if (i->nr_segs == 1 && iter_is_iovec(i)) {
   590			/* Single buffer from user */
   591			context.data_type = USER_BPF_DATA_USER;
   592			context.data_len = i->count;
 > 593			context.udata = i->iov->iov_base + i->iov_offset;
   594		} else {
   595			/* Multi buffer from user */
   596			struct iov_iter copy = *i;
   597			size_t copy_size = min_t(size_t, i->count, MAX_BPF_COPY_SIZE);
   598	
   599			context.data_type = USER_BPF_DATA_KERNEL;
   600			context.kdata = fast_data;
   601	
   602			if (unlikely(copy_size > sizeof(fast_data))) {
   603				temp = kmalloc(copy_size, GFP_NOWAIT);
   604	
   605				if (temp)
   606					context.kdata = temp;
   607				else
   608					copy_size = sizeof(fast_data);
   609			}
   610	
   611			context.data_len = copy_nofault(context.kdata,
   612							copy_size, &copy);
   613		}
   614	
   615		trace_call_bpf(&user->call, &context);
   616	
   617		kfree(temp);
   618	}
   619	

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