[PATCH 17/48] staging: etnaviv: allow etnaviv_ioctl_gem_info() locking to be interruptible

[Lucas Stach]

From: Russell King <rmk+ker...@arm.linux.org.uk>

Move the locking out of etnaviv_gem_mmap_offset() into its solitary
caller, and take the mutex using mutex_lock_interruptible().  This
allows etnaviv_ioctl_gem_info() to handle signals while trying to
obtain this lock.

Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
---
 drivers/staging/etnaviv/etnaviv_drv.c | 7 ++++++-
 drivers/staging/etnaviv/etnaviv_gem.c | 7 ++-----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/etnaviv/etnaviv_drv.c 
b/drivers/staging/etnaviv/etnaviv_drv.c
index 9962318075c5..a87de2e79fee 100644
--- a/drivers/staging/etnaviv/etnaviv_drv.c
+++ b/drivers/staging/etnaviv/etnaviv_drv.c
@@ -447,7 +447,12 @@ static int etnaviv_ioctl_gem_info(struct drm_device *dev, 
void *data,
        if (!obj)
                return -ENOENT;

-       ret = etnaviv_gem_mmap_offset(obj, &args->offset);
+       ret = mutex_lock_interruptible(&dev->struct_mutex);
+       if (ret == 0) {
+               ret = etnaviv_gem_mmap_offset(obj, &args->offset);
+
+               mutex_unlock(&dev->struct_mutex);
+       }

        drm_gem_object_unreference_unlocked(obj);

diff --git a/drivers/staging/etnaviv/etnaviv_gem.c 
b/drivers/staging/etnaviv/etnaviv_gem.c
index 38dee80d996c..b1984a4ac0c5 100644
--- a/drivers/staging/etnaviv/etnaviv_gem.c
+++ b/drivers/staging/etnaviv/etnaviv_gem.c
@@ -269,20 +269,17 @@ out:
        }
 }

-/** get mmap offset */
+/* get mmap offset - must be called under struct_mutex */
 int etnaviv_gem_mmap_offset(struct drm_gem_object *obj, uint64_t *offset)
 {
-       struct drm_device *dev = obj->dev;
        int ret;

-       mutex_lock(&dev->struct_mutex);
        /* Make it mmapable */
        ret = drm_gem_create_mmap_offset(obj);
        if (ret)
-               dev_err(dev->dev, "could not allocate mmap offset\n");
+               dev_err(obj->dev->dev, "could not allocate mmap offset\n");
        else
                *offset = drm_vma_node_offset_addr(&obj->vma_node);
-       mutex_unlock(&dev->struct_mutex);

        return ret;
 }
-- 
2.5.1