From: Robert Richter <rrich...@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 <tchalama...@cavium.com>.

Signed-off-by: Tirumalesh Chalamarla <tchalama...@cavium.com>
Reviewed-by: Marc Zyngier <marc.zyng...@arm.com>
Signed-off-by: Robert Richter <rrich...@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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to