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authorMichael Ellerman <michael@ellerman.id.au>2006-08-02 10:48:50 +1000
committerPaul Mackerras <paulus@samba.org>2006-09-26 15:24:34 +1000
commite12514650b167f48e952d50315fd492d01d42988 (patch)
tree8ac4f5ca248ef91a1a6550eba64cca2a80a9711b /arch/powerpc/kernel/irq.c
parent94983cb7881dff760d724759105a6f67935b571d (diff)
[POWERPC] Fix loop logic in irq_alloc_virt()
There's a bug in irq_alloc_virt() if it's asked for more than 1 interrupt, if it can't find a slot it might look past the end of the irq_map. To be clear: the bug is that the continue affects the inner for loop, not the outer one, so i becomes j + 1 and then we continue the inner loop without checking if i is still <= limit. This fixes it. No one in the kernel actually calls this with count > 1, so it's not critical. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/kernel/irq.c')
-rw-r--r--arch/powerpc/kernel/irq.c19
1 files changed, 10 insertions, 9 deletions
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index b4432332341..c3f58f2f9f5 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -777,7 +777,6 @@ unsigned int irq_alloc_virt(struct irq_host *host,
{
unsigned long flags;
unsigned int i, j, found = NO_IRQ;
- unsigned int limit = irq_virq_count - count;
if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
return NO_IRQ;
@@ -794,14 +793,16 @@ unsigned int irq_alloc_virt(struct irq_host *host,
/* Look for count consecutive numbers in the allocatable
* (non-legacy) space
*/
- for (i = NUM_ISA_INTERRUPTS; i <= limit; ) {
- for (j = i; j < (i + count); j++)
- if (irq_map[j].host != NULL) {
- i = j + 1;
- continue;
- }
- found = i;
- break;
+ for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
+ if (irq_map[i].host != NULL)
+ j = 0;
+ else
+ j++;
+
+ if (j == count) {
+ found = i - count + 1;
+ break;
+ }
}
if (found == NO_IRQ) {
spin_unlock_irqrestore(&irq_big_lock, flags);