arch/powerpc/xmon/xmon.c:3174 show_task() warn: unsigned 'p_state' is never less than zero.

From: kernel test robot
Date: Thu Aug 12 2021 - 13:39:04 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 1746f4db513563bb22e0ba0c419d0c90912dfae1
commit: 2f064a59a11ff9bc22e52e9678bc601404c7cb34 sched: Change task_struct::state
date: 8 weeks ago
config: powerpc64-randconfig-m031-20210812 (attached as .config)
compiler: powerpc-linux-gcc (GCC) 10.3.0

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

New smatch warnings:
arch/powerpc/xmon/xmon.c:3174 show_task() warn: unsigned 'p_state' is never less than zero.

Old smatch warnings:
arch/powerpc/include/asm/mmu.h:233 early_mmu_has_feature() warn: bitwise AND condition is false here
arch/powerpc/xmon/xmon.c:2798 dump() warn: '"d?

vim +/p_state +3174 arch/powerpc/xmon/xmon.c

3162
3163 static void show_task(struct task_struct *tsk)
3164 {
3165 unsigned int p_state = READ_ONCE(tsk->__state);
3166 char state;
3167
3168 /*
3169 * Cloned from kdb_task_state_char(), which is not entirely
3170 * appropriate for calling from xmon. This could be moved
3171 * to a common, generic, routine used by both.
3172 */
3173 state = (p_state == 0) ? 'R' :
> 3174 (p_state < 0) ? 'U' :
3175 (p_state & TASK_UNINTERRUPTIBLE) ? 'D' :
3176 (p_state & TASK_STOPPED) ? 'T' :
3177 (p_state & TASK_TRACED) ? 'C' :
3178 (tsk->exit_state & EXIT_ZOMBIE) ? 'Z' :
3179 (tsk->exit_state & EXIT_DEAD) ? 'E' :
3180 (p_state & TASK_INTERRUPTIBLE) ? 'S' : '?';
3181
3182 printf("%16px %16lx %16px %6d %6d %c %2d %s\n", tsk,
3183 tsk->thread.ksp, tsk->thread.regs,
3184 tsk->pid, rcu_dereference(tsk->parent)->pid,
3185 state, task_cpu(tsk),
3186 tsk->comm);
3187 }
3188

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Attachment: .config.gz
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