* Initialize the cpumask_of_cpu_map to contain a cpumask for cpu 0 in the initdata section. This allows references before the real cpumask_of_cpu_map is setup avoiding possible null pointer deref panics. Based on linux-2.6.tip/master Signed-off-by: Mike Travis --- arch/x86/kernel/setup_percpu.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) --- linux-2.6.tip.orig/arch/x86/kernel/setup_percpu.c +++ linux-2.6.tip/arch/x86/kernel/setup_percpu.c @@ -51,7 +51,7 @@ static void __init setup_node_to_cpumask static inline void setup_node_to_cpumask_map(void) { } #endif -#if defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) && defined(CONFIG_SMP) +#ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA /* * Copy data used in early init routines from the initial arrays to the * per cpu data areas. These arrays then become expendable and the @@ -81,16 +81,25 @@ static void __init setup_per_cpu_maps(vo } #ifdef CONFIG_HAVE_CPUMASK_OF_CPU_MAP -cpumask_t *cpumask_of_cpu_map __read_mostly; + +/* Configure an initial cpumask_of_cpu(0) for early users */ +static cpumask_t initial_cpumask_of_cpu_map __initdata = (cpumask_t) { { + [BITS_TO_LONGS(NR_CPUS)-1] = 1 +} }; +cpumask_t *cpumask_of_cpu_map __read_mostly = + (cpumask_t *)&initial_cpumask_of_cpu_map; EXPORT_SYMBOL(cpumask_of_cpu_map); -/* requires nr_cpu_ids to be initialized */ +/* Requires nr_cpu_ids to be initialized */ static void __init setup_cpumask_of_cpu(void) { int i; /* alloc_bootmem zeroes memory */ cpumask_of_cpu_map = alloc_bootmem_low(sizeof(cpumask_t) * nr_cpu_ids); +#ifdef CONFIG_DEBUG_PER_CPU_MAPS + printk(KERN_DEBUG "cpumask_of_cpu_map %p\n", cpumask_of_cpu_map); +#endif for (i = 0; i < nr_cpu_ids; i++) cpu_set(i, cpumask_of_cpu_map[i]); } -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/