Re: [PATCH bpf-next] bpf: remove is_return in struct bpf_session_run_ctx

Hi Menglong,

kernel test robot noticed the following build warnings:

[auto build test WARNING on bpf-next/master]

url:    https://github.com/intel-lab-lkp/linux/commits/Menglong-Dong/bpf-remove-is_return-in-struct-bpf_session_run_ctx/20250922-175833
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link:    https://lore.kernel.org/r/20250922095705.252519-1-dongml2%40chinatelecom.cn
patch subject: [PATCH bpf-next] bpf: remove is_return in struct bpf_session_run_ctx
config: i386-randconfig-r113-20250923 (https://download.01.org/0day-ci/archive/20250923/202509231550.BWhLcP9e-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250923/202509231550.BWhLcP9e-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 [off-list ref]
| Closes: https://lore.kernel.org/oe-kbuild-all/202509231550.BWhLcP9e-lkp@intel.com/ (local)

sparse warnings: (new ones prefixed by >>)
   kernel/trace/bpf_trace.c:833:41: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected void [noderef] __user *[addressable] [assigned] [usertype] sival_ptr @@     got void * @@
   kernel/trace/bpf_trace.c:833:41: sparse:     expected void [noderef] __user *[addressable] [assigned] [usertype] sival_ptr
   kernel/trace/bpf_trace.c:833:41: sparse:     got void *

quoted

kernel/trace/bpf_trace.c:3059:62: sparse: sparse: dubious: x | !y

   kernel/trace/bpf_trace.c:3512:52: sparse: sparse: cast removes address space '__user' of expression
   kernel/trace/bpf_trace.c:3526:56: sparse: sparse: cast removes address space '__user' of expression
   kernel/trace/bpf_trace.c:3540:52: sparse: sparse: cast removes address space '__user' of expression
   kernel/trace/bpf_trace.c:3547:56: sparse: sparse: cast removes address space '__user' of expression
   kernel/trace/bpf_trace.c:3555:52: sparse: sparse: cast removes address space '__user' of expression
   kernel/trace/bpf_trace.c:3563:56: sparse: sparse: cast removes address space '__user' of expression
   kernel/trace/bpf_trace.c: note: in included file (through include/linux/rbtree.h, include/linux/mm_types.h, include/linux/mmzone.h, ...):
   include/linux/rcupdate.h:869:9: sparse: sparse: context imbalance in 'uprobe_prog_run' - unexpected unlock

vim +3059 kernel/trace/bpf_trace.c

  3050	
  3051	static int uprobe_prog_run(struct bpf_uprobe *uprobe,
  3052				   unsigned long entry_ip,
  3053				   struct pt_regs *regs,
  3054				   bool is_return, void *data)
  3055	{
  3056		struct bpf_uprobe_multi_link *link = uprobe->link;
  3057		struct bpf_uprobe_multi_run_ctx run_ctx = {
  3058			.session_ctx = {

3059				.data = (void *)((unsigned long)data | !!is_return),

  3060			},
  3061			.entry_ip = entry_ip,
  3062			.uprobe = uprobe,
  3063		};
  3064		struct bpf_prog *prog = link->link.prog;
  3065		bool sleepable = prog->sleepable;
  3066		struct bpf_run_ctx *old_run_ctx;
  3067		int err;
  3068	
  3069		if (link->task && !same_thread_group(current, link->task))
  3070			return 0;
  3071	
  3072		if (sleepable)
  3073			rcu_read_lock_trace();
  3074		else
  3075			rcu_read_lock();
  3076	
  3077		migrate_disable();
  3078	
  3079		old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx);
  3080		err = bpf_prog_run(link->link.prog, regs);
  3081		bpf_reset_run_ctx(old_run_ctx);
  3082	
  3083		migrate_enable();
  3084	
  3085		if (sleepable)
  3086			rcu_read_unlock_trace();
  3087		else
  3088			rcu_read_unlock();
  3089		return err;
  3090	}
  3091	

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