Re: [PATCH v8 10/23] mm/shmem: Handle uffd-wp during fork()

From: Peter Xu <peterx@redhat.com>
To: kernel test robot <lkp@intel.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	kbuild-all@lists.01.org, Mike Kravetz <mike.kravetz@oracle.com>,
	Nadav Amit <nadav.amit@gmail.com>,
	Matthew Wilcox <willy@infradead.org>,
	Mike Rapoport <rppt@linux.vnet.ibm.com>,
	David Hildenbrand <david@redhat.com>,
	Hugh Dickins <hughd@google.com>,
	Jerome Glisse <jglisse@redhat.com>,
	"Kirill A . Shutemov" <kirill@shutemov.name>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Axel Rasmussen <axelrasmussen@google.com>,
	Alistair Popple <apopple@nvidia.com>
Subject: Re: [PATCH v8 10/23] mm/shmem: Handle uffd-wp during fork()
Date: Wed, 6 Apr 2022 08:18:05 -0400	[thread overview]
Message-ID: <Yk2E/RcVyR/wismh@xz-m1.local> (raw)
In-Reply-To: <202204061453.OXOxSh6e-lkp@intel.com>

I assume below should be the same issue as the allnoconfig one Andrew
reported, IOW after the fixup squashed this report along with the other one
in patch 4 should go away.  Let me know otherwise..

Thanks,

On Wed, Apr 06, 2022 at 02:16:56PM +0800, kernel test robot wrote:
> All warnings (new ones prefixed by >>):
> 
>    In file included from arch/ia64/include/asm/pgtable.h:153,
>                     from include/linux/pgtable.h:6,
>                     from arch/ia64/include/asm/uaccess.h:40,
>                     from include/linux/uaccess.h:11,
>                     from arch/ia64/include/asm/sections.h:11,
>                     from include/linux/interrupt.h:21,
>                     from include/linux/kernel_stat.h:9,
>                     from mm/memory.c:42:
>    arch/ia64/include/asm/mmu_context.h: In function 'reload_context':
>    arch/ia64/include/asm/mmu_context.h:127:48: warning: variable 'old_rr4' set but not used [-Wunused-but-set-variable]
>      127 |         unsigned long rr0, rr1, rr2, rr3, rr4, old_rr4;
>          |                                                ^~~~~~~
>    In file included from include/linux/mm_inline.h:9,
>                     from mm/memory.c:44:
>    include/linux/userfaultfd_k.h: In function 'pte_marker_entry_uffd_wp':
>    include/linux/userfaultfd_k.h:260:16: error: implicit declaration of function 'is_pte_marker_entry' [-Werror=implicit-function-declaration]
>      260 |         return is_pte_marker_entry(entry) &&
>          |                ^~~~~~~~~~~~~~~~~~~
>    include/linux/userfaultfd_k.h:261:14: error: implicit declaration of function 'pte_marker_get' [-Werror=implicit-function-declaration]
>      261 |             (pte_marker_get(entry) & PTE_MARKER_UFFD_WP);
>          |              ^~~~~~~~~~~~~~
>    include/linux/userfaultfd_k.h:261:38: error: 'PTE_MARKER_UFFD_WP' undeclared (first use in this function)
>      261 |             (pte_marker_get(entry) & PTE_MARKER_UFFD_WP);
>          |                                      ^~~~~~~~~~~~~~~~~~
>    include/linux/userfaultfd_k.h:261:38: note: each undeclared identifier is reported only once for each function it appears in
>    In file included from include/linux/mm_inline.h:10,
>                     from mm/memory.c:44:
>    include/linux/swapops.h: At top level:
>    include/linux/swapops.h:289:20: error: conflicting types for 'is_pte_marker_entry'; have 'bool(swp_entry_t)' {aka '_Bool(swp_entry_t)'}
>      289 | static inline bool is_pte_marker_entry(swp_entry_t entry)
>          |                    ^~~~~~~~~~~~~~~~~~~
>    In file included from include/linux/mm_inline.h:9,
>                     from mm/memory.c:44:
>    include/linux/userfaultfd_k.h:260:16: note: previous implicit declaration of 'is_pte_marker_entry' with type 'int()'
>      260 |         return is_pte_marker_entry(entry) &&
>          |                ^~~~~~~~~~~~~~~~~~~
>    In file included from include/linux/mm_inline.h:10,
>                     from mm/memory.c:44:
>    include/linux/swapops.h:294:26: error: conflicting types for 'pte_marker_get'; have 'pte_marker(swp_entry_t)' {aka 'long unsigned int(swp_entry_t)'}
>      294 | static inline pte_marker pte_marker_get(swp_entry_t entry)
>          |                          ^~~~~~~~~~~~~~
>    In file included from include/linux/mm_inline.h:9,
>                     from mm/memory.c:44:
>    include/linux/userfaultfd_k.h:261:14: note: previous implicit declaration of 'pte_marker_get' with type 'int()'
>      261 |             (pte_marker_get(entry) & PTE_MARKER_UFFD_WP);
>          |              ^~~~~~~~~~~~~~

-- 
Peter Xu