Re: [RFC PATCH v2 1/1] x86/pkeys: update PKRU to enable pkey 0 before XSAVE

[kernel test robot <lkp@intel.com>]

Hi Aruna,

[This is a private test report for your RFC patch.]
kernel test robot noticed the following build warnings:

[auto build test WARNING on tip/x86/core]
[also build test WARNING on tip/master tip/auto-latest linus/master v6.9-rc1 next-20240326]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Aruna-Ramakrishna/x86-pkeys-update-PKRU-to-enable-pkey-0-before-XSAVE/20240322-055950
base:   tip/x86/core
patch link:    https://lore.kernel.org/r/20240321215622.3396410-2-aruna.ramakrishna%40oracle.com
patch subject: [RFC PATCH v2 1/1] x86/pkeys: update PKRU to enable pkey 0 before XSAVE
config: x86_64-randconfig-123-20240326 (https://download.01.org/0day-ci/archive/20240327/202403270713.CDQA9ROT-lkp@intel.com/config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240327/202403270713.CDQA9ROT-lkp@intel.com/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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202403270713.CDQA9ROT-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
   arch/x86/kernel/fpu/signal.c: note: in included file (through arch/x86/include/asm/uaccess.h, include/linux/uaccess.h, include/linux/sched/task.h, ...):
   arch/x86/include/asm/uaccess_64.h:85:24: sparse: sparse: cast removes address space '__user' of expression
>> arch/x86/kernel/fpu/signal.c:80:34: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct xregs_state *xsave @@     got struct xregs_state [noderef] __user *buf @@
   arch/x86/kernel/fpu/signal.c:80:34: sparse:     expected struct xregs_state *xsave
   arch/x86/kernel/fpu/signal.c:80:34: sparse:     got struct xregs_state [noderef] __user *buf
   arch/x86/include/asm/uaccess_64.h:85:24: sparse: sparse: cast removes address space '__user' of expression
   arch/x86/include/asm/uaccess_64.h:85:24: sparse: sparse: cast removes address space '__user' of expression

vim +80 arch/x86/kernel/fpu/signal.c

    65	
    66	/*
    67	 * Update the value of PKRU register that was already pushed
    68	 * onto the signal frame.
    69	 */
    70	static inline int
    71	__update_pkru_in_sigframe(struct xregs_state __user *buf, u32 pkru)
    72	{
    73		int err = -EFAULT;
    74		struct _fpx_sw_bytes fx_sw;
    75		struct pkru_state *pk = NULL;
    76	
    77		if (unlikely(!check_xstate_in_sigframe((void __user *) buf, &fx_sw)))
    78			goto out;
    79	
  > 80		pk = get_xsave_addr_user(buf, XFEATURE_PKRU);
    81		if (!pk || !user_write_access_begin(buf, sizeof(struct xregs_state)))
    82			goto out;
    83		unsafe_put_user(pkru, (unsigned int __user *) pk, uaccess_end);
    84	
    85		err = 0;
    86	uaccess_end:
    87		user_access_end();
    88	out:
    89		return err;
    90	}
    91	

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