Re: [PATCH 1/2] staging: binder: add __user annotation in binder.c

From: Joe Perches
Date: Mon Mar 24 2014 - 20:51:38 EST


On Tue, 2014-03-25 at 01:24 +0100, Mathieu Maret wrote:
> Fix the following spare warning

sparse

> drivers/staging/android/binder.c:2691:21: warning: incorrect type in argument 1 (different address spaces)
[]
> diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c
[]
> @@ -2688,7 +2688,7 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
[]
> - if (put_user(BINDER_CURRENT_PROTOCOL_VERSION, &((struct binder_version *)ubuf)->protocol_version)) {
> + if (put_user(BINDER_CURRENT_PROTOCOL_VERSION, &((struct binder_version __user *)ubuf)->protocol_version)) {

That's certainly one way to do it, but I'd suggest
using a temporary instead

drivers/staging/android/binder.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c
index cfe4bc8..1f5e249 100644
--- a/drivers/staging/android/binder.c
+++ b/drivers/staging/android/binder.c
@@ -2683,16 +2683,20 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
binder_free_thread(proc, thread);
thread = NULL;
break;
- case BINDER_VERSION:
+ case BINDER_VERSION: {
+ struct binder_version __user *ver = ubuf;
+
if (size != sizeof(struct binder_version)) {
ret = -EINVAL;
goto err;
}
- if (put_user(BINDER_CURRENT_PROTOCOL_VERSION, &((struct binder_version *)ubuf)->protocol_version)) {
+ if (put_user(BINDER_CURRENT_PROTOCOL_VERSION,
+ &ver->protocol_version)) {
ret = -EINVAL;
goto err;
}
break;
+ }
default:
ret = -EINVAL;
goto err;


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