From: David Daney <[email protected]> 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 <[email protected]> --- kernel/irq/irqdomain.c | 11 ++++++----- 1 files changed, 6 insertions(+), 5 deletions(-) diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index af48e59..9d3e3ae 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -351,6 +351,7 @@ unsigned int irq_create_mapping(struct irq_domain *domain, irq_hw_number_t hwirq) { unsigned int virq, hint; + int irq; pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", domain, hwirq); @@ -380,14 +381,14 @@ unsigned int irq_create_mapping(struct irq_domain *domain, hint = hwirq % irq_virq_count; if (hint == 0) hint++; - virq = irq_alloc_desc_from(hint, 0); - if (!virq) - virq = irq_alloc_desc_from(1, 0); - if (!virq) { + irq = irq_alloc_desc_from(hint, 0); + if (irq <= 0) + irq = irq_alloc_desc_from(1, 0); + if (irq <= 0) { pr_debug("irq: -> virq allocation failed\n"); return 0; } - + virq = irq; if (irq_setup_virq(domain, virq, hwirq)) { if (domain->revmap_type != IRQ_DOMAIN_MAP_LEGACY) irq_free_desc(virq); -- 1.7.2.3 _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
