setup_per_cpu_areas() only setup __per_cpu_offset[] for each possible
cpu, but loongson_sysconf.nr_cpus can be greater than possible cpus
(due to reserved_cpus_mask). So in loongson3_ipi_interrupt(), percpu
access will touch the original varible in .data..percpu section which
has been freed. Without this patch, cpu-hotplug will cause memery
corruption.
Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx>
---
arch/mips/loongson/loongson-3/smp.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/arch/mips/loongson/loongson-3/smp.c b/arch/mips/loongson/loongson-3/smp.c
index e3c68b5..509877c 100644
--- a/arch/mips/loongson/loongson-3/smp.c
+++ b/arch/mips/loongson/loongson-3/smp.c
@@ -272,7 +272,7 @@ void loongson3_ipi_interrupt(struct pt_regs *regs)
if (action & SMP_ASK_C0COUNT) {
BUG_ON(cpu != 0);
c0count = read_c0_count();
- for (i = 1; i < loongson_sysconf.nr_cpus; i++)
+ for (i = 1; i < num_possible_cpus(); i++)
per_cpu(core0_c0count, i) = c0count;
}
}
--
1.7.7.3
