[PATCH 4.9] ion: Make user_ion_handle_put_nolock() a void function

[PATCH 4.9] ion: Make user_ion_handle_put_nolock() a void function

[Nathan Chancellor]

Clang warns:

  drivers/staging/android/ion/ion-ioctl.c:71:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
          if (--handle->user_ref_count == 0)
              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  drivers/staging/android/ion/ion-ioctl.c:74:9: note: uninitialized use occurs here
          return ret;
                 ^~~
  drivers/staging/android/ion/ion-ioctl.c:71:2: note: remove the 'if' if its condition is always true
          if (--handle->user_ref_count == 0)
          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  drivers/staging/android/ion/ion-ioctl.c:69:9: note: initialize the variable 'ret' to silence this warning
          int ret;
                 ^
                  = 0
  1 warning generated.

The return value of user_ion_handle_put_nolock() is not checked in its
one call site in user_ion_free_nolock() so just make
user_ion_handle_put_nolock() return void to remove the warning.

Fixes: a8200613c8c9 ("ion: Protect kref from userspace manipulation")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 drivers/staging/android/ion/ion-ioctl.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/android/ion/ion-ioctl.c b/drivers/staging/android/ion/ion-ioctl.c
index a27865b94416..e020a23d05f2 100644
--- a/drivers/staging/android/ion/ion-ioctl.c
+++ b/drivers/staging/android/ion/ion-ioctl.c
@@ -64,14 +64,10 @@ static struct ion_handle *pass_to_user(struct ion_handle *handle)
 }
 
 /* Must hold the client lock */
-static int user_ion_handle_put_nolock(struct ion_handle *handle)
+static void user_ion_handle_put_nolock(struct ion_handle *handle)
 {
-	int ret;
-
 	if (--handle->user_ref_count == 0)
-		ret = ion_handle_put_nolock(handle);
-
-	return ret;
+		ion_handle_put_nolock(handle);
 }
 
 static void user_ion_free_nolock(struct ion_client *client,

base-commit: 65be5f5665a580424a7b1102f1a04c4259c559b5
-- 
2.37.1

Patch "ion: Make user_ion_handle_put_nolock() a void function" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    ion: Make user_ion_handle_put_nolock() a void function

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ion-make-user_ion_handle_put_nolock-a-void-function.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From nathan@kernel.org  Mon Aug  1 10:53:38 2022
From: Nathan Chancellor <nathan@kernel.org>
Date: Wed, 27 Jul 2022 09:46:17 -0700
Subject: ion: Make user_ion_handle_put_nolock() a void function
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Sasha Levin <sashal@kernel.org>
Cc: Daniel Rosenberg <drosen@google.com>, stable@vger.kernel.org, llvm@lists.linux.dev, Nathan Chancellor <nathan@kernel.org>, kernel test robot <lkp@intel.com>
Message-ID: <20220727164617.980209-1-nathan@kernel.org>

From: Nathan Chancellor <nathan@kernel.org>

Clang warns:

  drivers/staging/android/ion/ion-ioctl.c:71:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
          if (--handle->user_ref_count == 0)
              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  drivers/staging/android/ion/ion-ioctl.c:74:9: note: uninitialized use occurs here
          return ret;
                 ^~~
  drivers/staging/android/ion/ion-ioctl.c:71:2: note: remove the 'if' if its condition is always true
          if (--handle->user_ref_count == 0)
          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  drivers/staging/android/ion/ion-ioctl.c:69:9: note: initialize the variable 'ret' to silence this warning
          int ret;
                 ^
                  = 0
  1 warning generated.

The return value of user_ion_handle_put_nolock() is not checked in its
one call site in user_ion_free_nolock() so just make
user_ion_handle_put_nolock() return void to remove the warning.

Fixes: a8200613c8c9 ("ion: Protect kref from userspace manipulation")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/staging/android/ion/ion-ioctl.c |    8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

--- a/drivers/staging/android/ion/ion-ioctl.c
+++ b/drivers/staging/android/ion/ion-ioctl.c
@@ -64,14 +64,10 @@ static struct ion_handle *pass_to_user(s
 }
 
 /* Must hold the client lock */
-static int user_ion_handle_put_nolock(struct ion_handle *handle)
+static void user_ion_handle_put_nolock(struct ion_handle *handle)
 {
-	int ret;
-
 	if (--handle->user_ref_count == 0)
-		ret = ion_handle_put_nolock(handle);
-
-	return ret;
+		ion_handle_put_nolock(handle);
 }
 
 static void user_ion_free_nolock(struct ion_client *client,


Patches currently in stable-queue which might be from nathan@kernel.org are

queue-4.9/arm-crypto-comment-out-gcc-warning-that-breaks-clang-builds.patch
queue-4.9/ion-make-user_ion_handle_put_nolock-a-void-function.patch

Re: [PATCH 4.9] ion: Make user_ion_handle_put_nolock() a void function

[Greg KH]

On Wed, Jul 27, 2022 at 09:46:17AM -0700, Nathan Chancellor wrote:
> Clang warns:
> 
>   drivers/staging/android/ion/ion-ioctl.c:71:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
>           if (--handle->user_ref_count == 0)
>               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   drivers/staging/android/ion/ion-ioctl.c:74:9: note: uninitialized use occurs here
>           return ret;
>                  ^~~
>   drivers/staging/android/ion/ion-ioctl.c:71:2: note: remove the 'if' if its condition is always true
>           if (--handle->user_ref_count == 0)
>           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   drivers/staging/android/ion/ion-ioctl.c:69:9: note: initialize the variable 'ret' to silence this warning
>           int ret;
>                  ^
>                   = 0
>   1 warning generated.
> 
> The return value of user_ion_handle_put_nolock() is not checked in its
> one call site in user_ion_free_nolock() so just make
> user_ion_handle_put_nolock() return void to remove the warning.
> 
> Fixes: a8200613c8c9 ("ion: Protect kref from userspace manipulation")
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
> ---
>  drivers/staging/android/ion/ion-ioctl.c | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)

Now queued up, thanks.

greg k-h