Re: [PATCH RFC bpf-next v2 3/5] bpf: cgroup_view iter

[kernel test robot <lkp@intel.com>]

Hi Hao,

[FYI, it's a private test report for your RFC patch.]
[auto build test ERROR on bpf-next/master]

url:    https://github.com/0day-ci/linux/commits/Hao-Luo/Extend-cgroup-interface-with-bpf/20220202-045743
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
config: hexagon-randconfig-r022-20220131 (https://download.01.org/0day-ci/archive/20220202/202202021120.j2esP3IH-lkp@intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 6b1e844b69f15bb7dffaf9365cd2b355d2eb7579)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/717a4c31e5bc20e5c7abf8c78a8c434fb15788a3
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Hao-Luo/Extend-cgroup-interface-with-bpf/20220202-045743
        git checkout 717a4c31e5bc20e5c7abf8c78a8c434fb15788a3
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash

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

All errors (new ones prefixed by >>):

>> kernel/bpf/cgroup_view_iter.c:32:18: error: implicit declaration of function 'cgroup_tryget' [-Werror,-Wimplicit-function-declaration]
           if (!cgroup || !cgroup_tryget(cgroup))
                           ^
>> kernel/bpf/cgroup_view_iter.c:77:3: error: implicit declaration of function 'cgroup_put' [-Werror,-Wimplicit-function-declaration]
                   cgroup_put(v);
                   ^
   kernel/bpf/cgroup_view_iter.c:77:3: note: did you mean 'cgroup_psi'?
   include/linux/cgroup.h:736:33: note: 'cgroup_psi' declared here
   static inline struct psi_group *cgroup_psi(struct cgroup *cgrp)
                                   ^
   2 errors generated.


vim +/cgroup_tryget +32 kernel/bpf/cgroup_view_iter.c

    11	
    12	static void *cgroup_view_seq_start(struct seq_file *seq, loff_t *pos)
    13	{
    14		struct bpf_dir_tag *tag;
    15		struct kernfs_node *kn;
    16		struct cgroup *cgroup;
    17		struct inode *dir;
    18	
    19		/* Only one session is supported. */
    20		if (*pos > 0)
    21			return NULL;
    22	
    23		dir = d_inode(seq->file->f_path.dentry->d_parent);
    24		tag = dir->i_private;
    25		if (!tag)
    26			return NULL;
    27	
    28		kn = tag->private;
    29	
    30		rcu_read_lock();
    31		cgroup = rcu_dereference(*(void __rcu __force **)&kn->priv);
  > 32		if (!cgroup || !cgroup_tryget(cgroup))
    33			cgroup = NULL;
    34		rcu_read_unlock();
    35	
    36		if (!cgroup)
    37			return NULL;
    38	
    39		if (*pos == 0)
    40			++*pos;
    41		return cgroup;
    42	}
    43	
    44	static void *cgroup_view_seq_next(struct seq_file *seq, void *v, loff_t *pos)
    45	{
    46		++*pos;
    47		return NULL;
    48	}
    49	
    50	struct bpf_iter__cgroup_view {
    51		__bpf_md_ptr(struct bpf_iter_meta *, meta);
    52		__bpf_md_ptr(struct cgroup *, cgroup);
    53	};
    54	
    55	DEFINE_BPF_ITER_FUNC(cgroup_view, struct bpf_iter_meta *meta, struct cgroup *cgroup)
    56	
    57	static int cgroup_view_seq_show(struct seq_file *seq, void *v)
    58	{
    59		struct bpf_iter__cgroup_view ctx;
    60		struct bpf_iter_meta meta;
    61		struct bpf_prog *prog;
    62		int ret = 0;
    63	
    64		ctx.meta = &meta;
    65		ctx.cgroup = v;
    66		meta.seq = seq;
    67		prog = bpf_iter_get_info(&meta, false);
    68		if (prog)
    69			ret = bpf_iter_run_prog(prog, &ctx);
    70	
    71		return ret;
    72	}
    73	
    74	static void cgroup_view_seq_stop(struct seq_file *seq, void *v)
    75	{
    76		if (v)
  > 77			cgroup_put(v);
    78	}
    79	

---
0-DAY CI Kernel Test Service, Intel Corporation
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