Revision b52723c5607f7684c2c0c075f86f86da0d7fb6d0 authored by KOSAKI Motohiro on 19 August 2010, 21:13:39 UTC, committed by Linus Torvalds on 20 August 2010, 16:34:55 UTC
Commit 0aad4b3124 ("oom: fold __out_of_memory into out_of_memory") introduced a tasklist_lock leak. Then it caused following obvious danger warnings and panic. ================================================ [ BUG: lock held when returning to user space! ] ------------------------------------------------ rsyslogd/1422 is leaving the kernel with locks still held! 1 lock held by rsyslogd/1422: #0: (tasklist_lock){.+.+.+}, at: [<ffffffff810faf64>] out_of_memory+0x164/0x3f0 BUG: scheduling while atomic: rsyslogd/1422/0x00000002 INFO: lockdep is turned off. This patch fixes it. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent be71cf2
irq.c
/*
* linux/arch/xtensa/kernel/irq.c
*
* Xtensa built-in interrupt controller and some generic functions copied
* from i386.
*
* Copyright (C) 2002 - 2006 Tensilica, Inc.
* Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
*
*
* Chris Zankel <chris@zankel.net>
* Kevin Chea
*
*/
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kernel_stat.h>
#include <asm/uaccess.h>
#include <asm/platform.h>
static unsigned int cached_irq_mask;
atomic_t irq_err_count;
/*
* do_IRQ handles all normal device IRQ's (the special
* SMP cross-CPU interrupts have their own specific
* handlers).
*/
asmlinkage void do_IRQ(int irq, struct pt_regs *regs)
{
struct pt_regs *old_regs = set_irq_regs(regs);
struct irq_desc *desc = irq_desc + irq;
if (irq >= NR_IRQS) {
printk(KERN_EMERG "%s: cannot handle IRQ %d\n",
__func__, irq);
}
irq_enter();
#ifdef CONFIG_DEBUG_STACKOVERFLOW
/* Debugging check for stack overflow: is there less than 1KB free? */
{
unsigned long sp;
__asm__ __volatile__ ("mov %0, a1\n" : "=a" (sp));
sp &= THREAD_SIZE - 1;
if (unlikely(sp < (sizeof(thread_info) + 1024)))
printk("Stack overflow in do_IRQ: %ld\n",
sp - sizeof(struct thread_info));
}
#endif
desc->handle_irq(irq, desc);
irq_exit();
set_irq_regs(old_regs);
}
/*
* Generic, controller-independent functions:
*/
int show_interrupts(struct seq_file *p, void *v)
{
int i = *(loff_t *) v, j;
struct irqaction * action;
unsigned long flags;
if (i == 0) {
seq_printf(p, " ");
for_each_online_cpu(j)
seq_printf(p, "CPU%d ",j);
seq_putc(p, '\n');
}
if (i < NR_IRQS) {
raw_spin_lock_irqsave(&irq_desc[i].lock, flags);
action = irq_desc[i].action;
if (!action)
goto skip;
seq_printf(p, "%3d: ",i);
#ifndef CONFIG_SMP
seq_printf(p, "%10u ", kstat_irqs(i));
#else
for_each_online_cpu(j)
seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
#endif
seq_printf(p, " %14s", irq_desc[i].chip->typename);
seq_printf(p, " %s", action->name);
for (action=action->next; action; action = action->next)
seq_printf(p, ", %s", action->name);
seq_putc(p, '\n');
skip:
raw_spin_unlock_irqrestore(&irq_desc[i].lock, flags);
} else if (i == NR_IRQS) {
seq_printf(p, "NMI: ");
for_each_online_cpu(j)
seq_printf(p, "%10u ", nmi_count(j));
seq_putc(p, '\n');
seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
}
return 0;
}
static void xtensa_irq_mask(unsigned int irq)
{
cached_irq_mask &= ~(1 << irq);
set_sr (cached_irq_mask, INTENABLE);
}
static void xtensa_irq_unmask(unsigned int irq)
{
cached_irq_mask |= 1 << irq;
set_sr (cached_irq_mask, INTENABLE);
}
static void xtensa_irq_enable(unsigned int irq)
{
variant_irq_enable(irq);
xtensa_irq_unmask(irq);
}
static void xtensa_irq_disable(unsigned int irq)
{
xtensa_irq_mask(irq);
variant_irq_disable(irq);
}
static void xtensa_irq_ack(unsigned int irq)
{
set_sr(1 << irq, INTCLEAR);
}
static int xtensa_irq_retrigger(unsigned int irq)
{
set_sr (1 << irq, INTSET);
return 1;
}
static struct irq_chip xtensa_irq_chip = {
.name = "xtensa",
.enable = xtensa_irq_enable,
.disable = xtensa_irq_disable,
.mask = xtensa_irq_mask,
.unmask = xtensa_irq_unmask,
.ack = xtensa_irq_ack,
.retrigger = xtensa_irq_retrigger,
};
void __init init_IRQ(void)
{
int index;
for (index = 0; index < XTENSA_NR_IRQS; index++) {
int mask = 1 << index;
if (mask & XCHAL_INTTYPE_MASK_SOFTWARE)
set_irq_chip_and_handler(index, &xtensa_irq_chip,
handle_simple_irq);
else if (mask & XCHAL_INTTYPE_MASK_EXTERN_EDGE)
set_irq_chip_and_handler(index, &xtensa_irq_chip,
handle_edge_irq);
else if (mask & XCHAL_INTTYPE_MASK_EXTERN_LEVEL)
set_irq_chip_and_handler(index, &xtensa_irq_chip,
handle_level_irq);
else if (mask & XCHAL_INTTYPE_MASK_TIMER)
set_irq_chip_and_handler(index, &xtensa_irq_chip,
handle_edge_irq);
else /* XCHAL_INTTYPE_MASK_WRITE_ERROR */
/* XCHAL_INTTYPE_MASK_NMI */
set_irq_chip_and_handler(index, &xtensa_irq_chip,
handle_level_irq);
}
cached_irq_mask = 0;
variant_init_irq();
}
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