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authorDavid Daney <david.daney@cavium.com>2012-04-05 16:52:13 -0700
committerGrant Likely <grant.likely@secretlab.ca>2012-04-10 22:39:16 -0600
commit5b7526e3a640e491075557acaa842c59c652c0c3 (patch)
tree43b3d5d33078b4683482b25559735e1e5d719a72
parent0034102808e0dbbf3a2394b82b1bb40b5778de9e (diff)
irq/irq_domain: Quit ignoring error returns from irq_alloc_desc_from().
In commit 4bbdd45a (irq_domain/powerpc: eliminate irq_map; use irq_alloc_desc() instead) code was added that ignores error returns from irq_alloc_desc_from() by (silently) casting the return value to unsigned. The negitive value error return now suddenly looks like a valid irq number. Commits cc79ca69 (irq_domain: Move irq_domain code from powerpc to kernel/irq) and 1bc04f2c (irq_domain: Add support for base irq and hwirq in legacy mappings) move this code to its current location in irqdomain.c The result of all of this is a null pointer dereference OOPS if one of the error cases is hit. The fix: Don't cast away the negativeness of the return value and then check for errors. Signed-off-by: David Daney <david.daney@cavium.com> Acked-by: Rob Herring <rob.herring@calxeda.com> [grant.likely: dropped addition of new 'irq' variable] Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
-rw-r--r--kernel/irq/irqdomain.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 3601f3fbf67c..9310a8d365b0 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -350,7 +350,8 @@ unsigned int irq_create_direct_mapping(struct irq_domain *domain)
unsigned int irq_create_mapping(struct irq_domain *domain,
irq_hw_number_t hwirq)
{
- unsigned int virq, hint;
+ unsigned int hint;
+ int virq;
pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", domain, hwirq);
@@ -381,9 +382,9 @@ unsigned int irq_create_mapping(struct irq_domain *domain,
if (hint == 0)
hint++;
virq = irq_alloc_desc_from(hint, 0);
- if (!virq)
+ if (virq <= 0)
virq = irq_alloc_desc_from(1, 0);
- if (!virq) {
+ if (virq <= 0) {
pr_debug("irq: -> virq allocation failed\n");
return 0;
}