Commit 5b7526e3 authored by David Daney's avatar David Daney Committed by Grant Likely

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: default avatarDavid Daney <david.daney@cavium.com>
Acked-by: default avatarRob Herring <rob.herring@calxeda.com>
[grant.likely: dropped addition of new 'irq' variable]
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent 00341028
...@@ -350,7 +350,8 @@ unsigned int irq_create_direct_mapping(struct irq_domain *domain) ...@@ -350,7 +350,8 @@ unsigned int irq_create_direct_mapping(struct irq_domain *domain)
unsigned int irq_create_mapping(struct irq_domain *domain, unsigned int irq_create_mapping(struct irq_domain *domain,
irq_hw_number_t hwirq) 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); 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, ...@@ -381,9 +382,9 @@ unsigned int irq_create_mapping(struct irq_domain *domain,
if (hint == 0) if (hint == 0)
hint++; hint++;
virq = irq_alloc_desc_from(hint, 0); virq = irq_alloc_desc_from(hint, 0);
if (!virq) if (virq <= 0)
virq = irq_alloc_desc_from(1, 0); virq = irq_alloc_desc_from(1, 0);
if (!virq) { if (virq <= 0) {
pr_debug("irq: -> virq allocation failed\n"); pr_debug("irq: -> virq allocation failed\n");
return 0; return 0;
} }
......
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