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percpu: fix unit_map[] verification in pcpu_setup_first_chunk() 

pcpu_setup_first_chunk() incorrectly used NR_CPUS as the impossible
unit number while unit number can equal and go over NR_CPUS with
sparse unit map.  This triggers BUG_ON() spuriously on machines which
have non-power-of-two number of cpus.  Use UINT_MAX instead.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Tony Vroon <tony@linx.net>
hifive-unleashed-5.1
Tejun Heo 2009-09-29 09:17:56 +09:00
parent 17d857be64
commit ffe0d5a575
1 changed files with 3 additions and 3 deletions
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6
mm/percpu.c
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@ -1604,7 +1604,7 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
unit_off = alloc_bootmem(nr_cpu_ids * sizeof(unit_off[0]));
for (cpu = 0; cpu < nr_cpu_ids; cpu++)
unit_map[cpu] = NR_CPUS;
unit_map[cpu] = UINT_MAX;
pcpu_first_unit_cpu = NR_CPUS;
for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) {
@ -1619,7 +1619,7 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
continue;
BUG_ON(cpu > nr_cpu_ids || !cpu_possible(cpu));
BUG_ON(unit_map[cpu] != NR_CPUS);
BUG_ON(unit_map[cpu] != UINT_MAX);
unit_map[cpu] = unit + i;
unit_off[cpu] = gi->base_offset + i * ai->unit_size;
@ -1632,7 +1632,7 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
pcpu_nr_units = unit;
for_each_possible_cpu(cpu)
BUG_ON(unit_map[cpu] == NR_CPUS);
BUG_ON(unit_map[cpu] == UINT_MAX);
pcpu_nr_groups = ai->nr_groups;
pcpu_group_offsets = group_offsets;