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[PATCH] alpha show_interrups() trashes argument
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This is a bug found by cpminer.  The show_interrupts function reuses i as a
for loop counter, and therefore trashes its contents, which are needed
later.

(akpm: rename local `i' to `irq', use for_each_inline_cpu())

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Eric Sesterhenn authored and Linus Torvalds committed Feb 1, 2006
1 parent 9a5e733 commit c5e3d98
Showing 1 changed file with 16 additions and 20 deletions.
36 changes: 16 additions & 20 deletions arch/alpha/kernel/irq.c
Original file line number Diff line number Diff line change
Expand Up @@ -68,34 +68,32 @@ show_interrupts(struct seq_file *p, void *v)
#ifdef CONFIG_SMP
int j;
#endif
int i = *(loff_t *) v;
int irq = *(loff_t *) v;
struct irqaction * action;
unsigned long flags;

#ifdef CONFIG_SMP
if (i == 0) {
if (irq == 0) {
seq_puts(p, " ");
for (i = 0; i < NR_CPUS; i++)
if (cpu_online(i))
seq_printf(p, "CPU%d ", i);
for_each_online_cpu(j)
seq_printf(p, "CPU%d ", j);
seq_putc(p, '\n');
}
#endif

if (i < ACTUAL_NR_IRQS) {
spin_lock_irqsave(&irq_desc[i].lock, flags);
action = irq_desc[i].action;
if (irq < ACTUAL_NR_IRQS) {
spin_lock_irqsave(&irq_desc[irq].lock, flags);
action = irq_desc[irq].action;
if (!action)
goto unlock;
seq_printf(p, "%3d: ",i);
seq_printf(p, "%3d: ", irq);
#ifndef CONFIG_SMP
seq_printf(p, "%10u ", kstat_irqs(i));
seq_printf(p, "%10u ", kstat_irqs(irq));
#else
for (j = 0; j < NR_CPUS; j++)
if (cpu_online(j))
seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
for_each_online_cpu(j)
seq_printf(p, "%10u ", kstat_cpu(j).irqs[irq]);
#endif
seq_printf(p, " %14s", irq_desc[i].handler->typename);
seq_printf(p, " %14s", irq_desc[irq].handler->typename);
seq_printf(p, " %c%s",
(action->flags & SA_INTERRUPT)?'+':' ',
action->name);
Expand All @@ -108,21 +106,19 @@ show_interrupts(struct seq_file *p, void *v)

seq_putc(p, '\n');
unlock:
spin_unlock_irqrestore(&irq_desc[i].lock, flags);
} else if (i == ACTUAL_NR_IRQS) {
spin_unlock_irqrestore(&irq_desc[irq].lock, flags);
} else if (irq == ACTUAL_NR_IRQS) {
#ifdef CONFIG_SMP
seq_puts(p, "IPI: ");
for (i = 0; i < NR_CPUS; i++)
if (cpu_online(i))
seq_printf(p, "%10lu ", cpu_data[i].ipi_count);
for_each_online_cpu(j)
seq_printf(p, "%10lu ", cpu_data[j].ipi_count);
seq_putc(p, '\n');
#endif
seq_printf(p, "ERR: %10lu\n", irq_err_count);
}
return 0;
}


/*
* handle_irq handles all normal device IRQ's (the special
* SMP cross-CPU interrupts have their own specific
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