[tip:irq/core] irqchip/gicv3-its: Add range check for number of allocated pages

From: tip-bot for Robert Richter
Date: Tue Sep 29 2015 - 04:16:11 EST


Commit-ID: 30f2136346cab91e1ffd9ee6370d76809f20487a
Gitweb: http://git.kernel.org/tip/30f2136346cab91e1ffd9ee6370d76809f20487a
Author: Robert Richter <rrichter@xxxxxxxxxx>
AuthorDate: Mon, 21 Sep 2015 22:58:34 +0200
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Tue, 29 Sep 2015 10:10:53 +0200

irqchip/gicv3-its: Add range check for number of allocated pages

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@xxxxxxxxxx>.

Signed-off-by: Tirumalesh Chalamarla <tchalamarla@xxxxxxxxxx>
Signed-off-by: Robert Richter <rrichter@xxxxxxxxxx>
Reviewed-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: Jason Cooper <jason@xxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1442869119-1814-2-git-send-email-rric@xxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
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 ac7ae2b..d9052fd 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -822,6 +822,7 @@ static int its_alloc_tables(const char *node_name, 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;

@@ -856,6 +857,14 @@ static int its_alloc_tables(const char *node_name, 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",
+ node_name, order, alloc_pages);
+ }
+
base = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
if (!base) {
err = -ENOMEM;
@@ -884,7 +893,7 @@ retry_baser:
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 9eeeb95..c0c8a2e 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -231,6 +231,7 @@
#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
--
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