[PATCH v2] irqchip: gicv3-its: Fix memory leak in its_free_tables()

Shanker Donthineni
2016-01-29T04:42:58Z

The current ITS driver has a memory leak in its_free_tables(). It
happens on tear down path of the driver when its_probe() call fails.
its_free_tables() should free the exact number of pages that have
been allocated, not just a single page as current code does.

This patch records the memory size for each ITS_BASERn at the time of
page allocation and uses the same size information when freeing pages
to fix the issue.

Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
---
[v1]->[v2]:
-rebase on tip of https://git.kernel.org/cgit/linux/kernel/git/maz/arm-platforms.git/commit/?h=irq/its-fixes-4.5&id=25ffe003bdc24492204e099fca0a467641d0fe1a
-refresh alloc_size value whenever page order changes.

drivers/irqchip/irq-gic-v3-its.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 3447549..fc1a34f 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -66,7 +66,10 @@ struct its_node {
unsigned long phys_base;
struct its_cmd_block *cmd_base;
struct its_cmd_block *cmd_write;
- void *tables[GITS_BASER_NR_REGS];
+ struct {
+ void *base;
+ u32 size;
+ } tables[GITS_BASER_NR_REGS];
struct its_collection *collections;
struct list_head its_device_list;
u64 flags;
@@ -807,9 +810,10 @@ static void its_free_tables(struct its_node *its)
int i;

for (i = 0; i < GITS_BASER_NR_REGS; i++) {
- if (its->tables[i]) {
- free_page((unsigned long)its->tables[i]);
- its->tables[i] = NULL;
+ if (its->tables[i].base) {
+ free_pages((unsigned long)its->tables[i].base,
+ get_order(its->tables[i].size));
+ its->tables[i].base = NULL;
}
}
}
@@ -880,6 +884,7 @@ retry_alloc_baser:
if (alloc_pages > GITS_BASER_PAGES_MAX) {
alloc_pages = GITS_BASER_PAGES_MAX;
order = get_order(GITS_BASER_PAGES_MAX * psz);
+ alloc_size = (1 << order) * PAGE_SIZE;
pr_warn("%s: Device Table too large, reduce its page order to %u (%u pages)\n",
node_name, order, alloc_pages);
}
@@ -890,7 +895,8 @@ retry_alloc_baser:
goto out_free;
}

- its->tables[i] = base;
+ its->tables[i].base = base;
+ its->tables[i].size = alloc_size;

retry_baser:
val = (virt_to_phys(base) |
--
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of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc.
is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.