From e1fb96e064e7157920f043f40ae801a5c18e57da Mon Sep 17 00:00:00 2001 From: Huacai Chen Date: Thu, 4 Jun 2015 14:53:47 +0800 Subject: [PATCH] MIPS: Loongson-3: Fix a cpu-hotplug issue in loongson3_ipi_interrupt() 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 Cc: John Crispin Cc: Steven J. Hill Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang Cc: Zhangjin Wu Patchwork: http://patchwork.linux-mips.org/patch/10524/ Signed-off-by: Ralf Baechle --- arch/mips/loongson/loongson-3/smp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/mips/loongson/loongson-3/smp.c b/arch/mips/loongson/loongson-3/smp.c index e3c68b5da18d..509877c6e9d9 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; } } -- 2.20.1