Hi Pingfan, kernel test robot noticed the following build warnings:
[auto build test WARNING on bpf-next/net] [also build test WARNING on bpf-next/master bpf/master arm64/for-next/core linus/master v6.15 next-20250529] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Pingfan-Liu/kexec_file-Make-kexec_image_load_default-global-visible/20250529-122124 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git net patch link: https://lore.kernel.org/r/20250529041744.16458-4-piliu%40redhat.com patch subject: [PATCHv3 3/9] bpf: Introduce bpf_copy_to_kernel() to buffer the content from bpf-prog config: riscv-randconfig-001-20250529 (https://download.01.org/0day-ci/archive/20250529/202505291926.ipusqcej-...@intel.com/config) compiler: clang version 21.0.0git (https://github.com/llvm/llvm-project f819f46284f2a79790038e1f6649172789734ae8) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250529/202505291926.ipusqcej-...@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 <l...@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202505291926.ipusqcej-...@intel.com/ All warnings (new ones prefixed by >>): >> kernel/bpf/helpers_carrier.c:74:17: warning: no previous prototype for >> function 'bpf_mem_range_result_put' [-Wmissing-prototypes] 74 | __bpf_kfunc int bpf_mem_range_result_put(struct mem_range_result *result) | ^ kernel/bpf/helpers_carrier.c:74:13: note: declare 'static' if the function is not intended to be used outside of this translation unit 74 | __bpf_kfunc int bpf_mem_range_result_put(struct mem_range_result *result) | ^ | static kernel/bpf/helpers_carrier.c:88:7: warning: variable 'kmalloc' set but not used [-Wunused-but-set-variable] 88 | bool kmalloc; | ^ >> kernel/bpf/helpers_carrier.c:82:17: warning: no previous prototype for >> function 'bpf_copy_to_kernel' [-Wmissing-prototypes] 82 | __bpf_kfunc int bpf_copy_to_kernel(const char *name, char *buf, int size) | ^ kernel/bpf/helpers_carrier.c:82:13: note: declare 'static' if the function is not intended to be used outside of this translation unit 82 | __bpf_kfunc int bpf_copy_to_kernel(const char *name, char *buf, int size) | ^ | static >> kernel/bpf/helpers_carrier.c:165:6: warning: variable 'ret' is used >> uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] 165 | if (!find_listener(item->str)) { | ^~~~~~~~~~~~~~~~~~~~~~~~~ kernel/bpf/helpers_carrier.c:174:9: note: uninitialized use occurs here 174 | return ret; | ^~~ kernel/bpf/helpers_carrier.c:165:2: note: remove the 'if' if its condition is always false 165 | if (!find_listener(item->str)) { | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 166 | hash_add(str_listeners, &item->node, hash); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 167 | } else { | ~~~~~~ kernel/bpf/helpers_carrier.c:149:9: note: initialize the variable 'ret' to silence this warning 149 | int ret; | ^ | = 0 4 warnings generated. vim +/bpf_mem_range_result_put +74 kernel/bpf/helpers_carrier.c 73 > 74 __bpf_kfunc int bpf_mem_range_result_put(struct mem_range_result *result) 75 { 76 return mem_range_result_put(result); 77 } 78 79 /* 80 * Cache the content in @buf into kernel 81 */ > 82 __bpf_kfunc int bpf_copy_to_kernel(const char *name, char *buf, int size) 83 { 84 struct mem_range_result *range; 85 struct mem_cgroup *memcg, *old_memcg; 86 struct str_listener *item; 87 resource_handler handler; 88 bool kmalloc; 89 char *kbuf; 90 int id, ret = 0; 91 92 id = srcu_read_lock(&srcu); 93 item = find_listener(name); 94 if (!item) { 95 srcu_read_unlock(&srcu, id); 96 return -EINVAL; 97 } 98 kmalloc = item->kmalloc; 99 handler = item->handler; 100 srcu_read_unlock(&srcu, id); 101 memcg = get_mem_cgroup_from_current(); 102 old_memcg = set_active_memcg(memcg); 103 range = kmalloc(sizeof(struct mem_range_result), GFP_KERNEL); 104 if (!range) { 105 pr_err("fail to allocate mem_range_result\n"); 106 ret = -ENOMEM; 107 goto err; 108 } 109 110 kref_init(&range->ref); 111 if (item->kmalloc) 112 kbuf = kmalloc(size, GFP_KERNEL | __GFP_ACCOUNT); 113 else 114 kbuf = __vmalloc(size, GFP_KERNEL | __GFP_ACCOUNT); 115 if (!kbuf) { 116 kfree(range); 117 ret = -ENOMEM; 118 goto err; 119 } 120 ret = copy_from_kernel_nofault(kbuf, buf, size); 121 if (unlikely(ret < 0)) { 122 kfree(range); 123 if (item->kmalloc) 124 kfree(kbuf); 125 else 126 vfree(kbuf); 127 ret = -EINVAL; 128 goto err; 129 } 130 range->kmalloc = item->kmalloc; 131 range->buf = kbuf; 132 range->buf_sz = size; 133 range->data_sz = size; 134 range->memcg = memcg; 135 mem_cgroup_tryget(memcg); 136 range->status = 0; 137 ret = handler(name, range); 138 mem_range_result_put(range); 139 err: 140 set_active_memcg(old_memcg); 141 mem_cgroup_put(memcg); 142 return ret; 143 } 144 145 int register_carrier_listener(struct carrier_listener *listener) 146 { 147 struct str_listener *item; 148 unsigned int hash; 149 int ret; 150 151 if (!listener->name) 152 return -EINVAL; 153 item = kmalloc(sizeof(*item), GFP_KERNEL); 154 if (!item) 155 return -ENOMEM; 156 item->str = kstrdup(listener->name, GFP_KERNEL); 157 if (!item->str) { 158 kfree(item); 159 return -ENOMEM; 160 } 161 item->handler = listener->handler; 162 item->kmalloc = listener->kmalloc; 163 hash = jhash(item->str, strlen(item->str), 0); 164 mutex_lock(&str_listeners_mutex); > 165 if (!find_listener(item->str)) { 166 hash_add(str_listeners, &item->node, hash); 167 } else { 168 kfree(item->str); 169 kfree(item); 170 ret = -EBUSY; 171 } 172 mutex_unlock(&str_listeners_mutex); 173 174 return ret; 175 } 176 EXPORT_SYMBOL(register_carrier_listener); 177 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
