[PATCH v4 1/5] irqchip, gicv3-its: Add range check for number of allocated pages

Robert Richter
2015-08-14T18:28:01Z

From: Robert Richter <rrichter@cavium.com>

The number of pages for the its table may exceed the maximum of 256.
Adding a range check and limitting the number to its maximum.

Based on a patch from Tirumalesh Chalamarla <tchalamarla@cavium.com>.

Signed-off-by: Tirumalesh Chalamarla <tchalamarla@cavium.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Robert Richter <rrichter@cavium.com>
---
drivers/irqchip/irq-gic-v3-its.c | 11 ++++++++++-
include/linux/irqchip/arm-gic-v3.h | 1 +
2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 1b7e155869f6..466edf8a7477 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -810,6 +810,7 @@ static int its_alloc_tables(struct its_node *its)
u64 entry_size = GITS_BASER_ENTRY_SIZE(val);
int order = get_order(psz);
int alloc_size;
+ int alloc_pages;
u64 tmp;
void *base;

@@ -844,6 +845,14 @@ static int its_alloc_tables(struct its_node *its)
}

alloc_size = (1 << order) * PAGE_SIZE;
+ alloc_pages = (alloc_size / psz);
+ if (alloc_pages > GITS_BASER_PAGES_MAX) {
+ alloc_pages = GITS_BASER_PAGES_MAX;
+ order = get_order(GITS_BASER_PAGES_MAX * psz);
+ pr_warn("%s: Device Table too large, reduce its page order to %u (%u pages)\n",
+ its->msi_chip.of_node->full_name, order, alloc_pages);
+ }
+
base = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
if (!base) {
err = -ENOMEM;
@@ -872,7 +881,7 @@ static int its_alloc_tables(struct its_node *its)
break;
}

- val |= (alloc_size / psz) - 1;
+ val |= alloc_pages - 1;

writeq_relaxed(val, its->base + GITS_BASER + i * 8);
tmp = readq_relaxed(its->base + GITS_BASER + i * 8);
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index ffbc034c8810..f28da189c4aa 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -229,6 +229,7 @@
#define GITS_BASER_PAGE_SIZE_16K (1UL << GITS_BASER_PAGE_SIZE_SHIFT)
#define GITS_BASER_PAGE_SIZE_64K (2UL << GITS_BASER_PAGE_SIZE_SHIFT)
#define GITS_BASER_PAGE_SIZE_MASK (3UL << GITS_BASER_PAGE_SIZE_SHIFT)
+#define GITS_BASER_PAGES_MAX 256

#define GITS_BASER_TYPE_NONE 0
#define GITS_BASER_TYPE_DEVICE 1
--
2.1.1