irqchip/gicv3-its: Fix memory leak in its_free_tables()

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>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Vikram Sethi <vikrams@codeaurora.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1454379584-21772-1-git-send-email-shankerd@codeaurora.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 11 insertions, 6 deletions

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 3447549fcc93..0a73632b28d5 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             order;
+        } 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,
+                                   its->tables[i].order);
+                        its->tables[i].base = NULL;
                 }
         }
 }
@@ -890,7 +894,8 @@ retry_alloc_baser:
                         goto out_free;
                 }
 
-                its->tables[i] = base;
+                its->tables[i].base = base;
+                its->tables[i].order = order;
 
 retry_baser:
                 val = (virt_to_phys(base)                                |
@@ -940,7 +945,7 @@ retry_baser:
                          * something is horribly wrong...
                          */
                         free_pages((unsigned long)base, order);
-                        its->tables[i] = NULL;
+                        its->tables[i].base = NULL;
 
                         switch (psz) {
                         case SZ_16K: