Hi Yosry, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on bpf-next/master] url: https://github.com/intel-lab-lkp/linux/commits/Yosry-Ahmed/bpf-rstat-cgroup-hierarchical-stats/20220611-034720 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master config: m68k-defconfig (https://download.01.org/0day-ci/archive/20220611/202206111453.xWWh2wMK-lkp@xxxxxxxxx/config) compiler: m68k-linux-gcc (GCC) 11.3.0 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/intel-lab-lkp/linux/commit/619857fd1ec4f351376ffcaaec20acc9aae9486f git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Yosry-Ahmed/bpf-rstat-cgroup-hierarchical-stats/20220611-034720 git checkout 619857fd1ec4f351376ffcaaec20acc9aae9486f # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash kernel/bpf/ kernel/cgroup/ If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): In file included from kernel/bpf/cgroup_iter.c:9: kernel/bpf/../cgroup/cgroup-internal.h:78:41: error: field 'iter' has incomplete type 78 | struct css_task_iter iter; | ^~~~ kernel/bpf/../cgroup/cgroup-internal.h: In function 'cgroup_is_dead': kernel/bpf/../cgroup/cgroup-internal.h:188:22: error: invalid use of undefined type 'const struct cgroup' 188 | return !(cgrp->self.flags & CSS_ONLINE); | ^~ kernel/bpf/../cgroup/cgroup-internal.h:188:37: error: 'CSS_ONLINE' undeclared (first use in this function); did you mean 'N_ONLINE'? 188 | return !(cgrp->self.flags & CSS_ONLINE); | ^~~~~~~~~~ | N_ONLINE kernel/bpf/../cgroup/cgroup-internal.h:188:37: note: each undeclared identifier is reported only once for each function it appears in kernel/bpf/../cgroup/cgroup-internal.h: In function 'notify_on_release': kernel/bpf/../cgroup/cgroup-internal.h:193:25: error: 'CGRP_NOTIFY_ON_RELEASE' undeclared (first use in this function) 193 | return test_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags); | ^~~~~~~~~~~~~~~~~~~~~~ kernel/bpf/../cgroup/cgroup-internal.h:193:54: error: invalid use of undefined type 'const struct cgroup' 193 | return test_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags); | ^~ kernel/bpf/../cgroup/cgroup-internal.h: In function 'put_css_set': kernel/bpf/../cgroup/cgroup-internal.h:207:39: error: invalid use of undefined type 'struct css_set' 207 | if (refcount_dec_not_one(&cset->refcount)) | ^~ kernel/bpf/../cgroup/cgroup-internal.h: In function 'get_css_set': kernel/bpf/../cgroup/cgroup-internal.h:220:27: error: invalid use of undefined type 'struct css_set' 220 | refcount_inc(&cset->refcount); | ^~ kernel/bpf/../cgroup/cgroup-internal.h: At top level: kernel/bpf/../cgroup/cgroup-internal.h:284:22: error: array type has incomplete element type 'struct cftype' 284 | extern struct cftype cgroup1_base_files[]; | ^~~~~~~~~~~~~~~~~~ kernel/bpf/cgroup_iter.c: In function 'cgroup_iter_seq_start': kernel/bpf/cgroup_iter.c:55:24: error: implicit declaration of function 'css_next_descendant_pre' [-Werror=implicit-function-declaration] 55 | return css_next_descendant_pre(NULL, p->start_css); | ^~~~~~~~~~~~~~~~~~~~~~~ >> kernel/bpf/cgroup_iter.c:55:24: warning: returning 'int' from a function with return type 'void *' makes pointer from integer without a cast [-Wint-conversion] 55 | return css_next_descendant_pre(NULL, p->start_css); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/bpf/cgroup_iter.c:57:24: error: implicit declaration of function 'css_next_descendant_post' [-Werror=implicit-function-declaration] 57 | return css_next_descendant_post(NULL, p->start_css); | ^~~~~~~~~~~~~~~~~~~~~~~~ kernel/bpf/cgroup_iter.c:57:24: warning: returning 'int' from a function with return type 'void *' makes pointer from integer without a cast [-Wint-conversion] 57 | return css_next_descendant_post(NULL, p->start_css); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/bpf/cgroup_iter.c: In function 'cgroup_iter_seq_next': kernel/bpf/cgroup_iter.c:83:24: warning: returning 'int' from a function with return type 'void *' makes pointer from integer without a cast [-Wint-conversion] 83 | return css_next_descendant_pre(curr, p->start_css); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/bpf/cgroup_iter.c:85:24: warning: returning 'int' from a function with return type 'void *' makes pointer from integer without a cast [-Wint-conversion] 85 | return css_next_descendant_post(curr, p->start_css); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/bpf/cgroup_iter.c:87:28: error: invalid use of undefined type 'struct cgroup_subsys_state' 87 | return curr->parent; | ^~ kernel/bpf/cgroup_iter.c: In function '__cgroup_iter_seq_show': kernel/bpf/cgroup_iter.c:100:38: error: invalid use of undefined type 'struct cgroup_subsys_state' 100 | if (css && cgroup_is_dead(css->cgroup)) | ^~ kernel/bpf/cgroup_iter.c:104:31: error: invalid use of undefined type 'struct cgroup_subsys_state' 104 | ctx.cgroup = css ? css->cgroup : NULL; | ^~ kernel/bpf/cgroup_iter.c: In function 'cgroup_iter_seq_init': kernel/bpf/cgroup_iter.c:137:29: error: invalid use of undefined type 'struct cgroup' 137 | p->start_css = &cgrp->self; | ^~ kernel/bpf/cgroup_iter.c: In function 'bpf_iter_attach_cgroup': kernel/bpf/cgroup_iter.c:157:24: error: implicit declaration of function 'cgroup_get_from_fd'; did you mean 'cgroup_get_from_id'? [-Werror=implicit-function-declaration] 157 | cgrp = cgroup_get_from_fd(fd); | ^~~~~~~~~~~~~~~~~~ | cgroup_get_from_id >> kernel/bpf/cgroup_iter.c:157:22: warning: assignment to 'struct cgroup *' from 'int' makes pointer from integer without a cast [-Wint-conversion] 157 | cgrp = cgroup_get_from_fd(fd); | ^ kernel/bpf/cgroup_iter.c:159:24: error: implicit declaration of function 'cgroup_get_from_path'; did you mean 'cgroup_get_from_id'? [-Werror=implicit-function-declaration] 159 | cgrp = cgroup_get_from_path("/"); | ^~~~~~~~~~~~~~~~~~~~ | cgroup_get_from_id kernel/bpf/cgroup_iter.c:159:22: warning: assignment to 'struct cgroup *' from 'int' makes pointer from integer without a cast [-Wint-conversion] 159 | cgrp = cgroup_get_from_path("/"); | ^ kernel/bpf/cgroup_iter.c: In function 'bpf_iter_cgroup_show_fdinfo': kernel/bpf/cgroup_iter.c:190:9: error: implicit declaration of function 'cgroup_path_ns'; did you mean 'cgroup_parent'? [-Werror=implicit-function-declaration] 190 | cgroup_path_ns(aux->cgroup.start, buf, PATH_MAX, | ^~~~~~~~~~~~~~ | cgroup_parent kernel/bpf/cgroup_iter.c: In function 'cgroup_iter_seq_next': kernel/bpf/cgroup_iter.c:88:1: error: control reaches end of non-void function [-Werror=return-type] 88 | } | ^ cc1: some warnings being treated as errors vim +55 kernel/bpf/cgroup_iter.c 41 42 static void *cgroup_iter_seq_start(struct seq_file *seq, loff_t *pos) 43 { 44 struct cgroup_iter_priv *p = seq->private; 45 46 mutex_lock(&cgroup_mutex); 47 48 /* support only one session */ 49 if (*pos > 0) 50 return NULL; 51 52 ++*pos; 53 p->terminate = false; 54 if (p->order == BPF_ITER_CGROUP_PRE) > 55 return css_next_descendant_pre(NULL, p->start_css); 56 else if (p->order == BPF_ITER_CGROUP_POST) 57 return css_next_descendant_post(NULL, p->start_css); 58 else /* BPF_ITER_CGROUP_PARENT_UP */ 59 return p->start_css; 60 } 61 62 static int __cgroup_iter_seq_show(struct seq_file *seq, 63 struct cgroup_subsys_state *css, int in_stop); 64 65 static void cgroup_iter_seq_stop(struct seq_file *seq, void *v) 66 { 67 /* pass NULL to the prog for post-processing */ 68 if (!v) 69 __cgroup_iter_seq_show(seq, NULL, true); 70 mutex_unlock(&cgroup_mutex); 71 } 72 73 static void *cgroup_iter_seq_next(struct seq_file *seq, void *v, loff_t *pos) 74 { 75 struct cgroup_subsys_state *curr = (struct cgroup_subsys_state *)v; 76 struct cgroup_iter_priv *p = seq->private; 77 78 ++*pos; 79 if (p->terminate) 80 return NULL; 81 82 if (p->order == BPF_ITER_CGROUP_PRE) 83 return css_next_descendant_pre(curr, p->start_css); 84 else if (p->order == BPF_ITER_CGROUP_POST) 85 return css_next_descendant_post(curr, p->start_css); 86 else 87 return curr->parent; 88 } 89 90 static int __cgroup_iter_seq_show(struct seq_file *seq, 91 struct cgroup_subsys_state *css, int in_stop) 92 { 93 struct cgroup_iter_priv *p = seq->private; 94 struct bpf_iter__cgroup ctx; 95 struct bpf_iter_meta meta; 96 struct bpf_prog *prog; 97 int ret = 0; 98 99 /* cgroup is dead, skip this element */ 100 if (css && cgroup_is_dead(css->cgroup)) 101 return 0; 102 103 ctx.meta = &meta; 104 ctx.cgroup = css ? css->cgroup : NULL; 105 meta.seq = seq; 106 prog = bpf_iter_get_info(&meta, in_stop); 107 if (prog) 108 ret = bpf_iter_run_prog(prog, &ctx); 109 110 /* if prog returns > 0, terminate after this element. */ 111 if (ret != 0) 112 p->terminate = true; 113 114 return 0; 115 } 116 117 static int cgroup_iter_seq_show(struct seq_file *seq, void *v) 118 { 119 return __cgroup_iter_seq_show(seq, (struct cgroup_subsys_state *)v, 120 false); 121 } 122 123 static const struct seq_operations cgroup_iter_seq_ops = { 124 .start = cgroup_iter_seq_start, 125 .next = cgroup_iter_seq_next, 126 .stop = cgroup_iter_seq_stop, 127 .show = cgroup_iter_seq_show, 128 }; 129 130 BTF_ID_LIST_SINGLE(bpf_cgroup_btf_id, struct, cgroup) 131 132 static int cgroup_iter_seq_init(void *priv, struct bpf_iter_aux_info *aux) 133 { 134 struct cgroup_iter_priv *p = (struct cgroup_iter_priv *)priv; 135 struct cgroup *cgrp = aux->cgroup.start; 136 137 p->start_css = &cgrp->self; 138 p->terminate = false; 139 p->order = aux->cgroup.order; 140 return 0; 141 } 142 143 static const struct bpf_iter_seq_info cgroup_iter_seq_info = { 144 .seq_ops = &cgroup_iter_seq_ops, 145 .init_seq_private = cgroup_iter_seq_init, 146 .seq_priv_size = sizeof(struct cgroup_iter_priv), 147 }; 148 149 static int bpf_iter_attach_cgroup(struct bpf_prog *prog, 150 union bpf_iter_link_info *linfo, 151 struct bpf_iter_aux_info *aux) 152 { 153 int fd = linfo->cgroup.cgroup_fd; 154 struct cgroup *cgrp; 155 156 if (fd) > 157 cgrp = cgroup_get_from_fd(fd); 158 else /* walk the entire hierarchy by default. */ 159 cgrp = cgroup_get_from_path("/"); 160 161 if (IS_ERR(cgrp)) 162 return PTR_ERR(cgrp); 163 164 aux->cgroup.start = cgrp; 165 aux->cgroup.order = linfo->cgroup.traversal_order; 166 return 0; 167 } 168 -- 0-DAY CI Kernel Test Service https://01.org/lkp