Re: [linux-next:master 3945/3956] mm/secretmem.c:107:6: error: implicit declaration of function 'mlock_future_check'

[Mike Rapoport <rppt@linux.ibm.com>]

On Mon, Jan 18, 2021 at 08:44:40AM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> head:   b3a3cbdec55b090d22a09f75efb7c7d34cb97f25
> commit: 5577d3803e8c46cfe63791e5fd0cb2c782d4db3b [3945/3956] mm: introduce memfd_secret system call to create "secret" memory areas
> config: riscv-randconfig-r003-20210118 (attached as .config)
> compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project bfd75bdf3fd62d4f5e7028d4122f9ffa517f2a09)
> reproduce (this is a W=1 build):
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # install riscv cross compiling tool for clang build
>         # apt-get install binutils-riscv64-linux-gnu
>         # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=5577d3803e8c46cfe63791e5fd0cb2c782d4db3b
>         git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
>         git fetch --no-tags linux-next master
>         git checkout 5577d3803e8c46cfe63791e5fd0cb2c782d4db3b
>         # save the attached .config to linux build tree
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv 
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All errors (new ones prefixed by >>):
>                                                                                      ^
>    In file included from mm/secretmem.c:14:
>    In file included from include/linux/pagemap.h:11:
>    In file included from include/linux/highmem.h:10:
>    In file included from include/linux/hardirq.h:10:
>    In file included from ./arch/riscv/include/generated/asm/hardirq.h:1:
>    In file included from include/asm-generic/hardirq.h:17:
>    In file included from include/linux/irq.h:20:
>    In file included from include/linux/io.h:13:
>    In file included from arch/riscv/include/asm/io.h:149:
>    include/asm-generic/io.h:1005:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
>            return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port;
>                                                      ~~~~~~~~~~ ^
> >> mm/secretmem.c:107:6: error: implicit declaration of function 'mlock_future_check' [-Werror,-Wimplicit-function-declaration]
>            if (mlock_future_check(vma->vm_mm, vma->vm_flags | VM_LOCKED, len))
>                ^
>    7 warnings and 1 error generated.
> 
> 
> vim +/mlock_future_check +107 mm/secretmem.c
> 
>     99	
>    100	static int secretmem_mmap(struct file *file, struct vm_area_struct *vma)
>    101	{
>    102		unsigned long len = vma->vm_end - vma->vm_start;
>    103	
>    104		if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0)
>    105			return -EINVAL;
>    106	
>  > 107		if (mlock_future_check(vma->vm_mm, vma->vm_flags | VM_LOCKED, len))
>    108			return -EAGAIN;
>    109	
>    110		vma->vm_ops = &secretmem_vm_ops;
>    111		vma->vm_flags |= VM_LOCKED;
>    112	
>    113		return 0;
>    114	}
>    115	
> 

The patch vs v5.11-rc3-mmots-2021-01-12-02-00 below should fix this:

From 51b925943bcf65b82d2ba3b30082a0665681585c Mon Sep 17 00:00:00 2001
From: Mike Rapoport <rppt@linux.ibm.com>
Date: Mon, 18 Jan 2021 10:03:29 +0200
Subject: [PATCH] riscv/Kconfig: make direct map manipulation options depend on MMU

ARCH_HAS_SET_DIRECT_MAP and ARCH_HAS_SET_MEMORY configuration options have
no meaning when CONFIG_MMU is disabled and there is no point to enable them
for the nommu case.

Add an explicit dependency on MMU for these options.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
 arch/riscv/Kconfig | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 2ef05ef921b5..dd295dba8a8d 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -25,8 +25,8 @@ config RISCV
 	select ARCH_HAS_KCOV
 	select ARCH_HAS_MMIOWB
 	select ARCH_HAS_PTE_SPECIAL
-	select ARCH_HAS_SET_DIRECT_MAP
-	select ARCH_HAS_SET_MEMORY
+	select ARCH_HAS_SET_DIRECT_MAP if MMU
+	select ARCH_HAS_SET_MEMORY if MMU
 	select ARCH_HAS_STRICT_KERNEL_RWX if MMU
 	select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
 	select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
-- 
2.28.0



-- 
Sincerely yours,
Mike.