Re: arch/x86/kernel/fpu/xstate.c:1691: warning: Excess function parameter 'tsk' description in 'fpu_xstate_prctl'

From: Nick Desaulniers
Date: Tue Sep 05 2023 - 13:10:20 EST

On Tue, Sep 5, 2023 at 6:36 AM kernel test robot <philip.li@xxxxxxxxx> wrote:
>
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: 3f86ed6ec0b390c033eae7f9c487a3fea268e027
> commit: f5c0b4f30416c670408a77be94703d04d22b57df x86/prctl: Remove pointless task argument
> date: 1 year, 4 months ago
> :::::: branch date: 14 hours ago
> :::::: commit date: 1 year, 4 months ago
> config: i386-allnoconfig (https://download.01.org/0day-ci/archive/20230905/202309052029.TNyqXyIT-lkp@xxxxxxxxx/config)
> compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230905/202309052029.TNyqXyIT-lkp@xxxxxxxxx/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: https://lore.kernel.org/r/202309052029.TNyqXyIT-lkp@xxxxxxxxx/
>
> All warnings (new ones prefixed by >>):
>
> >> arch/x86/kernel/fpu/xstate.c:1691: warning: Excess function parameter 'tsk' description in 'fpu_xstate_prctl'

FWIW, this is `make htmldocs` complaining about the comment above the function.

>
>
> vim +1691 arch/x86/kernel/fpu/xstate.c
>
> 980fe2fddcff21 Thomas Gleixner 2022-01-05 1671
> db8268df0983ad Chang S. Bae 2021-10-21 1672 /**
> db8268df0983ad Chang S. Bae 2021-10-21 1673 * fpu_xstate_prctl - xstate permission operations
> db8268df0983ad Chang S. Bae 2021-10-21 1674 * @tsk: Redundant pointer to current

^ this line should be deleted.

> db8268df0983ad Chang S. Bae 2021-10-21 1675 * @option: A subfunction of arch_prctl()
> db8268df0983ad Chang S. Bae 2021-10-21 1676 * @arg2: option argument
> db8268df0983ad Chang S. Bae 2021-10-21 1677 * Return: 0 if successful; otherwise, an error code
> db8268df0983ad Chang S. Bae 2021-10-21 1678 *
> db8268df0983ad Chang S. Bae 2021-10-21 1679 * Option arguments:
> db8268df0983ad Chang S. Bae 2021-10-21 1680 *
> db8268df0983ad Chang S. Bae 2021-10-21 1681 * ARCH_GET_XCOMP_SUPP: Pointer to user space u64 to store the info
> db8268df0983ad Chang S. Bae 2021-10-21 1682 * ARCH_GET_XCOMP_PERM: Pointer to user space u64 to store the info
> db8268df0983ad Chang S. Bae 2021-10-21 1683 * ARCH_REQ_XCOMP_PERM: Facility number requested
> db8268df0983ad Chang S. Bae 2021-10-21 1684 *
> db8268df0983ad Chang S. Bae 2021-10-21 1685 * For facilities which require more than one XSTATE component, the request
> db8268df0983ad Chang S. Bae 2021-10-21 1686 * must be the highest state component number related to that facility,
> db8268df0983ad Chang S. Bae 2021-10-21 1687 * e.g. for AMX which requires XFEATURE_XTILE_CFG(17) and
> db8268df0983ad Chang S. Bae 2021-10-21 1688 * XFEATURE_XTILE_DATA(18) this would be XFEATURE_XTILE_DATA(18).
> db8268df0983ad Chang S. Bae 2021-10-21 1689 */
> f5c0b4f30416c6 Thomas Gleixner 2022-05-12 1690 long fpu_xstate_prctl(int option, unsigned long arg2)
> db8268df0983ad Chang S. Bae 2021-10-21 @1691 {
> db8268df0983ad Chang S. Bae 2021-10-21 1692 u64 __user *uptr = (u64 __user *)arg2;
> db8268df0983ad Chang S. Bae 2021-10-21 1693 u64 permitted, supported;
> db8268df0983ad Chang S. Bae 2021-10-21 1694 unsigned long idx = arg2;
> 980fe2fddcff21 Thomas Gleixner 2022-01-05 1695 bool guest = false;
> db8268df0983ad Chang S. Bae 2021-10-21 1696
> db8268df0983ad Chang S. Bae 2021-10-21 1697 switch (option) {
> db8268df0983ad Chang S. Bae 2021-10-21 1698 case ARCH_GET_XCOMP_SUPP:
> db8268df0983ad Chang S. Bae 2021-10-21 1699 supported = fpu_user_cfg.max_features | fpu_user_cfg.legacy_features;
> db8268df0983ad Chang S. Bae 2021-10-21 1700 return put_user(supported, uptr);
> db8268df0983ad Chang S. Bae 2021-10-21 1701
> db8268df0983ad Chang S. Bae 2021-10-21 1702 case ARCH_GET_XCOMP_PERM:
> db8268df0983ad Chang S. Bae 2021-10-21 1703 /*
> db8268df0983ad Chang S. Bae 2021-10-21 1704 * Lockless snapshot as it can also change right after the
> db8268df0983ad Chang S. Bae 2021-10-21 1705 * dropping the lock.
> db8268df0983ad Chang S. Bae 2021-10-21 1706 */
> db8268df0983ad Chang S. Bae 2021-10-21 1707 permitted = xstate_get_host_group_perm();
> db8268df0983ad Chang S. Bae 2021-10-21 1708 permitted &= XFEATURE_MASK_USER_SUPPORTED;
> db8268df0983ad Chang S. Bae 2021-10-21 1709 return put_user(permitted, uptr);
> db8268df0983ad Chang S. Bae 2021-10-21 1710
> 980fe2fddcff21 Thomas Gleixner 2022-01-05 1711 case ARCH_GET_XCOMP_GUEST_PERM:
> 980fe2fddcff21 Thomas Gleixner 2022-01-05 1712 permitted = xstate_get_guest_group_perm();
> 980fe2fddcff21 Thomas Gleixner 2022-01-05 1713 permitted &= XFEATURE_MASK_USER_SUPPORTED;
> 980fe2fddcff21 Thomas Gleixner 2022-01-05 1714 return put_user(permitted, uptr);
> 980fe2fddcff21 Thomas Gleixner 2022-01-05 1715
> 980fe2fddcff21 Thomas Gleixner 2022-01-05 1716 case ARCH_REQ_XCOMP_GUEST_PERM:
> 980fe2fddcff21 Thomas Gleixner 2022-01-05 1717 guest = true;
> 980fe2fddcff21 Thomas Gleixner 2022-01-05 1718 fallthrough;
> 980fe2fddcff21 Thomas Gleixner 2022-01-05 1719
> db8268df0983ad Chang S. Bae 2021-10-21 1720 case ARCH_REQ_XCOMP_PERM:
> db8268df0983ad Chang S. Bae 2021-10-21 1721 if (!IS_ENABLED(CONFIG_X86_64))
> db8268df0983ad Chang S. Bae 2021-10-21 1722 return -EOPNOTSUPP;
> db8268df0983ad Chang S. Bae 2021-10-21 1723
> 980fe2fddcff21 Thomas Gleixner 2022-01-05 1724 return xstate_request_perm(idx, guest);
> db8268df0983ad Chang S. Bae 2021-10-21 1725
> db8268df0983ad Chang S. Bae 2021-10-21 1726 default:
> db8268df0983ad Chang S. Bae 2021-10-21 1727 return -EINVAL;
> db8268df0983ad Chang S. Bae 2021-10-21 1728 }
> db8268df0983ad Chang S. Bae 2021-10-21 1729 }
> db8268df0983ad Chang S. Bae 2021-10-21 1730
>
> :::::: The code at line 1691 was first introduced by commit
> :::::: db8268df0983adc2bb1fb48c9e5f7bfbb5f617f3 x86/arch_prctl: Add controls for dynamic XSTATE components
>
> :::::: TO: Chang S. Bae <chang.seok.bae@xxxxxxxxx>
> :::::: CC: Borislav Petkov <bp@xxxxxxx>
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki
>
>


--
Thanks,
~Nick Desaulniers