Messages in this thread | | | Subject | Re: [PATCHv2 4/4] staging: android: ion: Add ioctl to query available heaps | From | Laura Abbott <> | Date | Fri, 2 Sep 2016 14:27:21 -0700 |
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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-Drop-heap-type-masks/20160902-071022 > 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/make.cross -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
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