Messages in this thread | | | Date | Tue, 30 Apr 2024 09:41:32 +0800 | From | kernel test robot <> | Subject | kernel/sched/isolation.c:143 housekeeping_setup() warn: always true condition '(first_cpu >= 0) => (0-u32max >= 0)' |
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tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 98369dccd2f8e16bf4c6621053af7aa4821dcf8e commit: 257bf89d84121280904800acd25cc2c444c717ae sched/isolation: Fix boot crash when maxcpus < first housekeeping CPU date: 2 days ago config: xtensa-randconfig-r081-20240429 (https://download.01.org/0day-ci/archive/20240430/202404300915.WNvfwBz3-lkp@intel.com/config) compiler: xtensa-linux-gcc (GCC) 13.2.0
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 <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202404300915.WNvfwBz3-lkp@intel.com/
New smatch warnings: kernel/sched/isolation.c:143 housekeeping_setup() warn: always true condition '(first_cpu >= 0) => (0-u32max >= 0)'
Old smatch warnings: arch/xtensa/include/asm/thread_info.h:97 current_thread_info() warn: inconsistent indenting
vim +143 kernel/sched/isolation.c
117 118 static int __init housekeeping_setup(char *str, unsigned long flags) 119 { 120 cpumask_var_t non_housekeeping_mask, housekeeping_staging; 121 unsigned int first_cpu; 122 int err = 0; 123 124 if ((flags & HK_FLAG_TICK) && !(housekeeping.flags & HK_FLAG_TICK)) { 125 if (!IS_ENABLED(CONFIG_NO_HZ_FULL)) { 126 pr_warn("Housekeeping: nohz unsupported." 127 " Build with CONFIG_NO_HZ_FULL\n"); 128 return 0; 129 } 130 } 131 132 alloc_bootmem_cpumask_var(&non_housekeeping_mask); 133 if (cpulist_parse(str, non_housekeeping_mask) < 0) { 134 pr_warn("Housekeeping: nohz_full= or isolcpus= incorrect CPU range\n"); 135 goto free_non_housekeeping_mask; 136 } 137 138 alloc_bootmem_cpumask_var(&housekeeping_staging); 139 cpumask_andnot(housekeeping_staging, 140 cpu_possible_mask, non_housekeeping_mask); 141 142 first_cpu = cpumask_first_and(cpu_present_mask, housekeeping_staging); > 143 if (first_cpu >= nr_cpu_ids || first_cpu >= setup_max_cpus) { 144 __cpumask_set_cpu(smp_processor_id(), housekeeping_staging); 145 __cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask); 146 if (!housekeeping.flags) { 147 pr_warn("Housekeeping: must include one present CPU, " 148 "using boot CPU:%d\n", smp_processor_id()); 149 } 150 } 151 152 if (cpumask_empty(non_housekeeping_mask)) 153 goto free_housekeeping_staging; 154 155 if (!housekeeping.flags) { 156 /* First setup call ("nohz_full=" or "isolcpus=") */ 157 enum hk_type type; 158 159 for_each_set_bit(type, &flags, HK_TYPE_MAX) 160 housekeeping_setup_type(type, housekeeping_staging); 161 } else { 162 /* Second setup call ("nohz_full=" after "isolcpus=" or the reverse) */ 163 enum hk_type type; 164 unsigned long iter_flags = flags & housekeeping.flags; 165 166 for_each_set_bit(type, &iter_flags, HK_TYPE_MAX) { 167 if (!cpumask_equal(housekeeping_staging, 168 housekeeping.cpumasks[type])) { 169 pr_warn("Housekeeping: nohz_full= must match isolcpus=\n"); 170 goto free_housekeeping_staging; 171 } 172 } 173 174 iter_flags = flags & ~housekeeping.flags; 175 176 for_each_set_bit(type, &iter_flags, HK_TYPE_MAX) 177 housekeeping_setup_type(type, housekeeping_staging); 178 } 179 180 if ((flags & HK_FLAG_TICK) && !(housekeeping.flags & HK_FLAG_TICK)) 181 tick_nohz_full_setup(non_housekeeping_mask); 182 183 housekeeping.flags |= flags; 184 err = 1; 185 186 free_housekeeping_staging: 187 free_bootmem_cpumask_var(housekeeping_staging); 188 free_non_housekeeping_mask: 189 free_bootmem_cpumask_var(non_housekeeping_mask); 190 191 return err; 192 } 193
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