On 09/01/2016 04:44 PM, kbuild test robot wrote:
Hi Laura,
[auto build test WARNING on next-20160825] [cannot apply to staging/staging-testing v4.8-rc4 v4.8-rc3 v4.8-rc2 v4.8-rc4] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] [Suggest to use git(>=2.9.0) format-patch --base=<commit> (or --base=auto for convenience) to record what (public, well-known) commit your patch series was built on] [Check https://git-scm.com/docs/git-format-patch for more information]
url: https://github.com/0day-ci/linux/commits/Laura-Abbott/staging-android-ion-Dr... config: mips-allyesconfig (attached as .config) compiler: mips-linux-gnu-gcc (Debian 5.4.0-6) 5.4.0 20160609 reproduce: wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/ma... -O ~/bin/make.cross chmod +x ~/bin/make.cross # save the attached .config to linux build tree make.cross ARCH=mips
All warnings (new ones prefixed by >>):
drivers/staging/android/ion/ion.c: In function 'ion_query_heaps':
drivers/staging/android/ion/ion.c:1181:3: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
(struct ion_heap_data __user *)query->heaps; ^
botching-up-ioctls.txt says:
* Pointers are __u64, cast from/to a uintprt_t on the userspace side and from/to a void __user * in the kernel. Try really hard not to delay this conversion or worse, fiddle the raw __u64 through your code since that diminishes the checking tools like sparse can provide.
This doesn't seem like it will work on 32-bit systems since you'll end up with the warning above. Is there a better option or did I misunderstand how that is supposed to work?
Thanks, Laura