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802bf931f2
Impact: fix bug where new irq_desc uses old cpumask pointers which are freed. As Yinghai pointed out, init_copy_one_irq_desc() copies the old desc to the new desc overwriting the cpumask pointers. Since the old_desc and the cpumask pointers are freed, then memory corruption will occur if these old pointers are used. Move the allocation of these pointers to after the copy. Signed-off-by: Mike Travis <travis@sgi.com> Cc: Yinghai Lu <yinghai@kernel.org>
133 lines
2.9 KiB
C
133 lines
2.9 KiB
C
/*
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* NUMA irq-desc migration code
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*
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* Migrate IRQ data structures (irq_desc, chip_data, etc.) over to
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* the new "home node" of the IRQ.
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*/
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#include <linux/irq.h>
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#include <linux/module.h>
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#include <linux/random.h>
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#include <linux/interrupt.h>
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#include <linux/kernel_stat.h>
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#include "internals.h"
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static void init_copy_kstat_irqs(struct irq_desc *old_desc,
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struct irq_desc *desc,
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int cpu, int nr)
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{
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unsigned long bytes;
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init_kstat_irqs(desc, cpu, nr);
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if (desc->kstat_irqs != old_desc->kstat_irqs) {
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/* Compute how many bytes we need per irq and allocate them */
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bytes = nr * sizeof(unsigned int);
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memcpy(desc->kstat_irqs, old_desc->kstat_irqs, bytes);
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}
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}
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static void free_kstat_irqs(struct irq_desc *old_desc, struct irq_desc *desc)
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{
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if (old_desc->kstat_irqs == desc->kstat_irqs)
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return;
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kfree(old_desc->kstat_irqs);
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old_desc->kstat_irqs = NULL;
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}
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static bool init_copy_one_irq_desc(int irq, struct irq_desc *old_desc,
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struct irq_desc *desc, int cpu)
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{
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memcpy(desc, old_desc, sizeof(struct irq_desc));
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if (!init_alloc_desc_masks(desc, cpu, false)) {
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printk(KERN_ERR "irq %d: can not get new irq_desc cpumask "
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"for migration.\n", irq);
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return false;
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}
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spin_lock_init(&desc->lock);
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desc->cpu = cpu;
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lockdep_set_class(&desc->lock, &irq_desc_lock_class);
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init_copy_kstat_irqs(old_desc, desc, cpu, nr_cpu_ids);
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init_copy_desc_masks(old_desc, desc);
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arch_init_copy_chip_data(old_desc, desc, cpu);
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return true;
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}
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static void free_one_irq_desc(struct irq_desc *old_desc, struct irq_desc *desc)
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{
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free_kstat_irqs(old_desc, desc);
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arch_free_chip_data(old_desc, desc);
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}
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static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
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int cpu)
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{
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struct irq_desc *desc;
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unsigned int irq;
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unsigned long flags;
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int node;
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irq = old_desc->irq;
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spin_lock_irqsave(&sparse_irq_lock, flags);
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/* We have to check it to avoid races with another CPU */
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desc = irq_desc_ptrs[irq];
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if (desc && old_desc != desc)
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goto out_unlock;
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node = cpu_to_node(cpu);
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desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
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if (!desc) {
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printk(KERN_ERR "irq %d: can not get new irq_desc "
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"for migration.\n", irq);
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/* still use old one */
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desc = old_desc;
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goto out_unlock;
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}
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if (!init_copy_one_irq_desc(irq, old_desc, desc, cpu)) {
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/* still use old one */
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kfree(desc);
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desc = old_desc;
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goto out_unlock;
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}
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irq_desc_ptrs[irq] = desc;
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/* free the old one */
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free_one_irq_desc(old_desc, desc);
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kfree(old_desc);
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out_unlock:
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spin_unlock_irqrestore(&sparse_irq_lock, flags);
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return desc;
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}
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struct irq_desc *move_irq_desc(struct irq_desc *desc, int cpu)
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{
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int old_cpu;
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int node, old_node;
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/* those all static, do move them */
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if (desc->irq < NR_IRQS_LEGACY)
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return desc;
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old_cpu = desc->cpu;
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if (old_cpu != cpu) {
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node = cpu_to_node(cpu);
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old_node = cpu_to_node(old_cpu);
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if (old_node != node)
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desc = __real_move_irq_desc(desc, cpu);
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else
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desc->cpu = cpu;
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}
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return desc;
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}
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