Re: arch/x86/kernel/cpu/sgx/virt.c:59:13: sparse: sparse: incorrect type in assignment (different base types)

[Philip Li <philip.li@intel.com>]

On Wed, Nov 20, 2024 at 10:05:26AM -0500, Steven Rostedt wrote:
> On Wed, 20 Nov 2024 13:59:39 +0800
> kernel test robot <lkp@intel.com> wrote:
> 
> > Hi Steven,
> > 
> > First bad commit (maybe != root cause):
> 
> Does not look to be root cause.

thanks for info, we will ignore this commit to avoid report this issue
against it.

> 
> -- Steve
> 
> > 
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head:   bf9aa14fc523d2763fc9a10672a709224e8fcaf4
> > commit: 59cbd4eea48fdbc68fc17a29ad71188fea74b28b KVM: Remove HIGH_RES_TIMERS dependency
> > date:   3 months ago
> > config: x86_64-randconfig-r133-20241119 (https://download.01.org/0day-ci/archive/20241120/202411201356.pXoYlKFB-lkp@intel.com/config)
> > compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99)
> > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241120/202411201356.pXoYlKFB-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/202411201356.pXoYlKFB-lkp@intel.com/
> > 
> > sparse warnings: (new ones prefixed by >>)
> > >> arch/x86/kernel/cpu/sgx/virt.c:59:13: sparse: sparse: incorrect type in assignment (different base types) @@     expected int [assigned] ret @@     got restricted vm_fault_t @@  
> >    arch/x86/kernel/cpu/sgx/virt.c:59:13: sparse:     expected int [assigned] ret
> >    arch/x86/kernel/cpu/sgx/virt.c:59:13: sparse:     got restricted vm_fault_t
> > >> arch/x86/kernel/cpu/sgx/virt.c:60:20: sparse: sparse: restricted vm_fault_t degrades to integer
> > >> arch/x86/kernel/cpu/sgx/virt.c:354:36: sparse: sparse: cast removes address space '__user' of expression  
> >    arch/x86/kernel/cpu/sgx/virt.c:385:24: sparse: sparse: cast removes address space '__user' of expression
> >    arch/x86/kernel/cpu/sgx/virt.c:385:43: sparse: sparse: cast removes address space '__user' of expression
> >    arch/x86/kernel/cpu/sgx/virt.c:385:58: sparse: sparse: cast removes address space '__user' of expression
> >    arch/x86/kernel/cpu/sgx/virt.c: note: in included file (through include/linux/miscdevice.h):
> >    include/linux/list.h:83:21: sparse: sparse: self-comparison always evaluates to true
> >    include/linux/list.h:83:21: sparse: sparse: self-comparison always evaluates to true
> > 
> > vim +59 arch/x86/kernel/cpu/sgx/virt.c
> > 
> > 540745ddbc70eab Sean Christopherson 2021-03-19  32  
> > 540745ddbc70eab Sean Christopherson 2021-03-19  33  static int __sgx_vepc_fault(struct sgx_vepc *vepc,
> > 540745ddbc70eab Sean Christopherson 2021-03-19  34  			    struct vm_area_struct *vma, unsigned long addr)
> > 540745ddbc70eab Sean Christopherson 2021-03-19  35  {
> > 540745ddbc70eab Sean Christopherson 2021-03-19  36  	struct sgx_epc_page *epc_page;
> > 540745ddbc70eab Sean Christopherson 2021-03-19  37  	unsigned long index, pfn;
> > 540745ddbc70eab Sean Christopherson 2021-03-19  38  	int ret;
> > 540745ddbc70eab Sean Christopherson 2021-03-19  39  
> > 540745ddbc70eab Sean Christopherson 2021-03-19  40  	WARN_ON(!mutex_is_locked(&vepc->lock));
> > 540745ddbc70eab Sean Christopherson 2021-03-19  41  
> > 540745ddbc70eab Sean Christopherson 2021-03-19  42  	/* Calculate index of EPC page in virtual EPC's page_array */
> > 540745ddbc70eab Sean Christopherson 2021-03-19  43  	index = vma->vm_pgoff + PFN_DOWN(addr - vma->vm_start);
> > 540745ddbc70eab Sean Christopherson 2021-03-19  44  
> > 540745ddbc70eab Sean Christopherson 2021-03-19  45  	epc_page = xa_load(&vepc->page_array, index);
> > 540745ddbc70eab Sean Christopherson 2021-03-19  46  	if (epc_page)
> > 540745ddbc70eab Sean Christopherson 2021-03-19  47  		return 0;
> > 540745ddbc70eab Sean Christopherson 2021-03-19  48  
> > 540745ddbc70eab Sean Christopherson 2021-03-19  49  	epc_page = sgx_alloc_epc_page(vepc, false);
> > 540745ddbc70eab Sean Christopherson 2021-03-19  50  	if (IS_ERR(epc_page))
> > 540745ddbc70eab Sean Christopherson 2021-03-19  51  		return PTR_ERR(epc_page);
> > 540745ddbc70eab Sean Christopherson 2021-03-19  52  
> > 540745ddbc70eab Sean Christopherson 2021-03-19  53  	ret = xa_err(xa_store(&vepc->page_array, index, epc_page, GFP_KERNEL));
> > 540745ddbc70eab Sean Christopherson 2021-03-19  54  	if (ret)
> > 540745ddbc70eab Sean Christopherson 2021-03-19  55  		goto err_free;
> > 540745ddbc70eab Sean Christopherson 2021-03-19  56  
> > 540745ddbc70eab Sean Christopherson 2021-03-19  57  	pfn = PFN_DOWN(sgx_get_epc_phys_addr(epc_page));
> > 540745ddbc70eab Sean Christopherson 2021-03-19  58  
> > 540745ddbc70eab Sean Christopherson 2021-03-19 @59  	ret = vmf_insert_pfn(vma, addr, pfn);
> > 540745ddbc70eab Sean Christopherson 2021-03-19 @60  	if (ret != VM_FAULT_NOPAGE) {
> > 540745ddbc70eab Sean Christopherson 2021-03-19  61  		ret = -EFAULT;
> > 540745ddbc70eab Sean Christopherson 2021-03-19  62  		goto err_delete;
> > 540745ddbc70eab Sean Christopherson 2021-03-19  63  	}
> > 540745ddbc70eab Sean Christopherson 2021-03-19  64  
> > 540745ddbc70eab Sean Christopherson 2021-03-19  65  	return 0;
> > 540745ddbc70eab Sean Christopherson 2021-03-19  66  
> > 540745ddbc70eab Sean Christopherson 2021-03-19  67  err_delete:
> > 540745ddbc70eab Sean Christopherson 2021-03-19  68  	xa_erase(&vepc->page_array, index);
> > 540745ddbc70eab Sean Christopherson 2021-03-19  69  err_free:
> > 540745ddbc70eab Sean Christopherson 2021-03-19  70  	sgx_free_epc_page(epc_page);
> > 540745ddbc70eab Sean Christopherson 2021-03-19  71  	return ret;
> > 540745ddbc70eab Sean Christopherson 2021-03-19  72  }
> > 540745ddbc70eab Sean Christopherson 2021-03-19  73  
> > 
> > :::::: The code at line 59 was first introduced by commit
> > :::::: 540745ddbc70eabdc7dbd3fcc00fe4fb17cd59ba x86/sgx: Introduce virtual EPC for use by KVM guests
> > 
> > :::::: TO: Sean Christopherson <sean.j.christopherson@intel.com>
> > :::::: CC: Borislav Petkov <bp@suse.de>
> > 
> 
>