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Date:   Tue, 31 May 2022 18:07:04 +0100
From:   Catalin Marinas <catalin.marinas@arm.com>
To:     kernel test robot <lkp@intel.com>
Cc:     Mark Brown <broonie@kernel.org>, kbuild-all@lists.01.org,
        linux-kernel@vger.kernel.org
Subject: Re: arch/arm64/kernel/signal.c:663:43: sparse: sparse: incorrect
 type in argument 1 (different address spaces)
Message-ID: <YpZLONkmubdmO8II@arm.com>
References: <202205280710.c7k1K4sD-lkp@intel.com>
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In-Reply-To: <202205280710.c7k1K4sD-lkp@intel.com>
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On Sat, May 28, 2022 at 07:40:31AM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   bf272460d744112bacd4c4d562592decbf0edf64
> commit: a1f4ccd25cc256255813f584f10e5527369d4a02 arm64/sme: Provide Kconfig for SME
> date:   5 weeks ago
> config: arm64-randconfig-s032-20220527 (https://download.01.org/0day-ci/archive/20220528/202205280710.c7k1K4sD-lkp@intel.com/config)
> compiler: aarch64-linux-gcc (GCC) 11.3.0
> reproduce:
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # apt-get install sparse
>         # sparse version: v0.6.4-14-g5a0004b5-dirty
>         # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a1f4ccd25cc256255813f584f10e5527369d4a02
>         git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>         git fetch --no-tags linus master
>         git checkout a1f4ccd25cc256255813f584f10e5527369d4a02
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=arm64 SHELL=/bin/bash arch/arm64/kernel/
> 
> If you fix the issue, kindly add following tag where applicable
> Reported-by: kernel test robot <lkp@intel.com>
> 
> 
> sparse warnings: (new ones prefixed by >>)
> >> arch/arm64/kernel/signal.c:663:43: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct user_ctxs [noderef] __user *user @@     got struct user_ctxs * @@
>    arch/arm64/kernel/signal.c:663:43: sparse:     expected struct user_ctxs [noderef] __user *user
>    arch/arm64/kernel/signal.c:663:43: sparse:     got struct user_ctxs *
>    arch/arm64/kernel/signal.c:933:26: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected void ( [noderef] [usertype] __user *[assigned] [usertype] sigtramp )( ... ) @@     got void * @@
>    arch/arm64/kernel/signal.c:933:26: sparse:     expected void ( [noderef] [usertype] __user *[assigned] [usertype] sigtramp )( ... )
>    arch/arm64/kernel/signal.c:933:26: sparse:     got void *
> >> arch/arm64/kernel/signal.c:394:35: sparse: sparse: dereference of noderef expression
> >> arch/arm64/kernel/signal.c:394:35: sparse: sparse: dereference of noderef expression
>    arch/arm64/kernel/signal.c:428:53: sparse: sparse: dereference of noderef expression
>    arch/arm64/kernel/signal.c:428:53: sparse: sparse: dereference of noderef expression
> 
> vim +663 arch/arm64/kernel/signal.c
> 
> 47ccb02868cead Dave Martin      2017-06-15  620  
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  621  static int restore_sigframe(struct pt_regs *regs,
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  622  			    struct rt_sigframe __user *sf)
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  623  {
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  624  	sigset_t set;
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  625  	int i, err;
> 47ccb02868cead Dave Martin      2017-06-15  626  	struct user_ctxs user;
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  627  
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  628  	err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  629  	if (err == 0)
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  630  		set_current_blocked(&set);
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  631  
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  632  	for (i = 0; i < 31; i++)
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  633  		__get_user_error(regs->regs[i], &sf->uc.uc_mcontext.regs[i],
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  634  				 err);
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  635  	__get_user_error(regs->sp, &sf->uc.uc_mcontext.sp, err);
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  636  	__get_user_error(regs->pc, &sf->uc.uc_mcontext.pc, err);
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  637  	__get_user_error(regs->pstate, &sf->uc.uc_mcontext.pstate, err);
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  638  
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  639  	/*
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  640  	 * Avoid sys_rt_sigreturn() restarting.
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  641  	 */
> 17c28958600928 Dave Martin      2017-08-01  642  	forget_syscall(regs);
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  643  
> dbd4d7ca563fd0 Mark Rutland     2016-03-01  644  	err |= !valid_user_regs(&regs->user_regs, current);
> 47ccb02868cead Dave Martin      2017-06-15  645  	if (err == 0)
> 47ccb02868cead Dave Martin      2017-06-15  646  		err = parse_user_sigframe(&user, sf);
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  647  
> 6d502b6ba1b267 Suzuki K Poulose 2020-01-13  648  	if (err == 0 && system_supports_fpsimd()) {
> 8cd969d28fd284 Dave Martin      2017-10-31  649  		if (!user.fpsimd)
> 8cd969d28fd284 Dave Martin      2017-10-31  650  			return -EINVAL;
> 8cd969d28fd284 Dave Martin      2017-10-31  651  
> 8cd969d28fd284 Dave Martin      2017-10-31  652  		if (user.sve) {
> 8cd969d28fd284 Dave Martin      2017-10-31  653  			if (!system_supports_sve())
> 8cd969d28fd284 Dave Martin      2017-10-31  654  				return -EINVAL;
> 8cd969d28fd284 Dave Martin      2017-10-31  655  
> 8cd969d28fd284 Dave Martin      2017-10-31  656  			err = restore_sve_fpsimd_context(&user);
> 8cd969d28fd284 Dave Martin      2017-10-31  657  		} else {
> 47ccb02868cead Dave Martin      2017-06-15  658  			err = restore_fpsimd_context(user.fpsimd);
> 8cd969d28fd284 Dave Martin      2017-10-31  659  		}
> 8cd969d28fd284 Dave Martin      2017-10-31  660  	}
> 2c020ed8d148f7 Catalin Marinas  2012-03-05  661  
> 39782210eb7e87 Mark Brown       2022-04-19  662  	if (err == 0 && system_supports_sme() && user.za)
> 39782210eb7e87 Mark Brown       2022-04-19 @663  		err = restore_za_context(&user);

I think the restore_za_context() definition is wrong. struct user_ctxs
__user *user shouldn't have the '__user' annotation, that's for the
pointers inside the structure. So:

diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index edb2d9206a78..b0980fbb6bc7 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -385,7 +385,7 @@ static int preserve_za_context(struct za_context __user *ctx)
 	return err ? -EFAULT : 0;
 }
 
-static int restore_za_context(struct user_ctxs __user *user)
+static int restore_za_context(struct user_ctxs *user)
 {
 	int err;
 	unsigned int vq;

I'll do some proper patches tomorrow and send them for -rc1.

-- 
Catalin