On Wed, Mar 8, 2023 at 7:02 AM kernel test robot <lkp@xxxxxxxxx> wrote: > > Hi Andrii, > > I love your patch! Perhaps something to improve: > > [auto build test WARNING on bpf-next/master] > > url: https://github.com/intel-lab-lkp/linux/commits/Andrii-Nakryiko/bpf-factor-out-fetching-basic-kfunc-metadata/20230308-115539 > base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master > patch link: https://lore.kernel.org/r/20230308035416.2591326-4-andrii%40kernel.org > patch subject: [PATCH v4 bpf-next 3/8] bpf: add support for open-coded iterator loops > config: hexagon-randconfig-r015-20230305 (https://download.01.org/0day-ci/archive/20230308/202303082209.VIxMyiGz-lkp@xxxxxxxxx/config) > compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project 67409911353323ca5edf2049ef0df54132fa1ca7) > 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/8f263e1296a91ff154a033d7cffbac3ee0ebf2ae > git remote add linux-review https://github.com/intel-lab-lkp/linux > git fetch --no-tags linux-review Andrii-Nakryiko/bpf-factor-out-fetching-basic-kfunc-metadata/20230308-115539 > git checkout 8f263e1296a91ff154a033d7cffbac3ee0ebf2ae > # save the config file > mkdir build_dir && cp config build_dir/.config > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon olddefconfig > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash kernel/bpf/ > > If you fix the issue, kindly add following tag where applicable > | Reported-by: kernel test robot <lkp@xxxxxxxxx> > | Link: https://lore.kernel.org/oe-kbuild-all/202303082209.VIxMyiGz-lkp@xxxxxxxxx/ > > All warnings (new ones prefixed by >>): > > In file included from kernel/bpf/verifier.c:7: > In file included from include/linux/bpf-cgroup.h:5: > In file included from include/linux/bpf.h:31: > In file included from include/linux/memcontrol.h:13: > In file included from include/linux/cgroup.h:26: > In file included from include/linux/kernel_stat.h:9: > In file included from include/linux/interrupt.h:11: > In file included from include/linux/hardirq.h:11: > In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1: > In file included from include/asm-generic/hardirq.h:17: > In file included from include/linux/irq.h:20: > In file included from include/linux/io.h:13: > In file included from arch/hexagon/include/asm/io.h:334: > include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > val = __raw_readb(PCI_IOBASE + addr); > ~~~~~~~~~~ ^ > include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr)); > ~~~~~~~~~~ ^ > include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu' > #define __le16_to_cpu(x) ((__force __u16)(__le16)(x)) > ^ > In file included from kernel/bpf/verifier.c:7: > In file included from include/linux/bpf-cgroup.h:5: > In file included from include/linux/bpf.h:31: > In file included from include/linux/memcontrol.h:13: > In file included from include/linux/cgroup.h:26: > In file included from include/linux/kernel_stat.h:9: > In file included from include/linux/interrupt.h:11: > In file included from include/linux/hardirq.h:11: > In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1: > In file included from include/asm-generic/hardirq.h:17: > In file included from include/linux/irq.h:20: > In file included from include/linux/io.h:13: > In file included from arch/hexagon/include/asm/io.h:334: > include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); > ~~~~~~~~~~ ^ > include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu' > #define __le32_to_cpu(x) ((__force __u32)(__le32)(x)) > ^ > In file included from kernel/bpf/verifier.c:7: > In file included from include/linux/bpf-cgroup.h:5: > In file included from include/linux/bpf.h:31: > In file included from include/linux/memcontrol.h:13: > In file included from include/linux/cgroup.h:26: > In file included from include/linux/kernel_stat.h:9: > In file included from include/linux/interrupt.h:11: > In file included from include/linux/hardirq.h:11: > In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1: > In file included from include/asm-generic/hardirq.h:17: > In file included from include/linux/irq.h:20: > In file included from include/linux/io.h:13: > In file included from arch/hexagon/include/asm/io.h:334: > include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > __raw_writeb(value, PCI_IOBASE + addr); > ~~~~~~~~~~ ^ > include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr); > ~~~~~~~~~~ ^ > include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] > __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr); > ~~~~~~~~~~ ^ > >> kernel/bpf/verifier.c:1244:23: warning: variable 'j' is uninitialized when used here [-Wuninitialized] > if (slot->slot_type[j] == STACK_ITER) > ^ > kernel/bpf/verifier.c:1229:15: note: initialize the variable 'j' to silence this warning > int spi, i, j; > ^ > = 0 > 7 warnings generated. > > > vim +/j +1244 kernel/bpf/verifier.c > > 1224 > 1225 static bool is_iter_reg_valid_uninit(struct bpf_verifier_env *env, > 1226 struct bpf_reg_state *reg, int nr_slots) > 1227 { > 1228 struct bpf_func_state *state = func(env, reg); > 1229 int spi, i, j; > 1230 > 1231 /* For -ERANGE (i.e. spi not falling into allocated stack slots), we > 1232 * will do check_mem_access to check and update stack bounds later, so > 1233 * return true for that case. > 1234 */ > 1235 spi = iter_get_spi(env, reg, nr_slots); > 1236 if (spi == -ERANGE) > 1237 return true; > 1238 if (spi < 0) > 1239 return spi; also, this should be return false > 1240 > 1241 for (i = 0; i < nr_slots; i++) { > 1242 struct bpf_stack_state *slot = &state->stack[spi - i]; > 1243 for (j = 0; j < BPF_REG_SIZE; j++) got lost during rebasing, sigh. I have a test that's testing this exact condition to be checked properly, and it is passing (that is proper return false is returned here) consistently with the garbage value of j :( Anyways, restored for loop here. > > 1244 if (slot->slot_type[j] == STACK_ITER) > 1245 return false; > 1246 } > 1247 > 1248 return true; > 1249 } > 1250 > > -- > 0-DAY CI Kernel Test Service > https://github.com/intel/lkp-tests
