[linux-next:master 4752/5832] error[E0433]: failed to resolve: could not find `mm` in the crate root

[linux-next:master 4752/5832] error[E0433]: failed to resolve: could not find `mm` in the crate root

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   0a00723f4c2d0b273edd0737f236f103164a08eb
commit: 64f43d565d3869b4fcba438ef3ed6cfb7ed8fee7 [4752/5832] rust: miscdevice: add mmap support
config: riscv-randconfig-r071-20250427 (https://download.01.org/0day-ci/archive/20250507/202505071753.kldNHYVQ-lkp@intel.com/config)
compiler: clang version 21.0.0git (https://github.com/llvm/llvm-project f819f46284f2a79790038e1f6649172789734ae8)
rustc: rustc 1.78.0 (9b00956e5 2024-04-29)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250507/202505071753.kldNHYVQ-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/202505071753.kldNHYVQ-lkp@intel.com/

All errors (new ones prefixed by >>):

   820 |         insl(addr, buffer, count);
   |         ^~~~~~~~~~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:106:53: note: expanded from macro 'insl'
   106 | #define insl(addr, buffer, count) __insl(PCI_IOBASE + (addr), buffer, count)
   |                                          ~~~~~~~~~~ ^
   In file included from rust/helpers/helpers.c:10:
   In file included from rust/helpers/blk.c:3:
   In file included from include/linux/blk-mq.h:5:
   In file included from include/linux/blkdev.h:9:
   In file included from include/linux/blk_types.h:10:
   In file included from include/linux/bvec.h:10:
   In file included from include/linux/highmem.h:12:
   In file included from include/linux/hardirq.h:11:
   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:12:
   In file included from arch/riscv/include/asm/io.h:136:
   include/asm-generic/io.h:829:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   829 |         outsb(addr, buffer, count);
   |         ^~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:118:55: note: expanded from macro 'outsb'
   118 | #define outsb(addr, buffer, count) __outsb(PCI_IOBASE + (addr), buffer, count)
   |                                            ~~~~~~~~~~ ^
   In file included from rust/helpers/helpers.c:10:
   In file included from rust/helpers/blk.c:3:
   In file included from include/linux/blk-mq.h:5:
   In file included from include/linux/blkdev.h:9:
   In file included from include/linux/blk_types.h:10:
   In file included from include/linux/bvec.h:10:
   In file included from include/linux/highmem.h:12:
   In file included from include/linux/hardirq.h:11:
   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:12:
   In file included from arch/riscv/include/asm/io.h:136:
   include/asm-generic/io.h:838:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   838 |         outsw(addr, buffer, count);
   |         ^~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:119:55: note: expanded from macro 'outsw'
   119 | #define outsw(addr, buffer, count) __outsw(PCI_IOBASE + (addr), buffer, count)
   |                                            ~~~~~~~~~~ ^
   In file included from rust/helpers/helpers.c:10:
   In file included from rust/helpers/blk.c:3:
   In file included from include/linux/blk-mq.h:5:
   In file included from include/linux/blkdev.h:9:
   In file included from include/linux/blk_types.h:10:
   In file included from include/linux/bvec.h:10:
   In file included from include/linux/highmem.h:12:
   In file included from include/linux/hardirq.h:11:
   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:12:
   In file included from arch/riscv/include/asm/io.h:136:
   include/asm-generic/io.h:847:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   847 |         outsl(addr, buffer, count);
   |         ^~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/io.h:120:55: note: expanded from macro 'outsl'
   120 | #define outsl(addr, buffer, count) __outsl(PCI_IOBASE + (addr), buffer, count)
   |                                            ~~~~~~~~~~ ^
   In file included from rust/helpers/helpers.c:10:
   In file included from rust/helpers/blk.c:3:
   In file included from include/linux/blk-mq.h:5:
   In file included from include/linux/blkdev.h:9:
   In file included from include/linux/blk_types.h:10:
   In file included from include/linux/bvec.h:10:
   In file included from include/linux/highmem.h:12:
   In file included from include/linux/hardirq.h:11:
   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:12:
   In file included from arch/riscv/include/asm/io.h:136:
   include/asm-generic/io.h:1175:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   1175 |         return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port;
   |                                                   ~~~~~~~~~~ ^
   clang diag: arch/riscv/include/asm/io.h:104:53: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: arch/riscv/include/asm/io.h:105:53: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: arch/riscv/include/asm/io.h:106:53: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: arch/riscv/include/asm/io.h:118:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: arch/riscv/include/asm/io.h:119:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: arch/riscv/include/asm/io.h:120:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: include/asm-generic/io.h:1175:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: arch/riscv/include/asm/io.h:104:53: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: arch/riscv/include/asm/io.h:105:53: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: arch/riscv/include/asm/io.h:106:53: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: arch/riscv/include/asm/io.h:118:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: arch/riscv/include/asm/io.h:119:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: arch/riscv/include/asm/io.h:120:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: include/asm-generic/io.h:1175:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   7 warnings generated.
   clang diag: arch/riscv/include/asm/io.h:104:53: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: arch/riscv/include/asm/io.h:105:53: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: arch/riscv/include/asm/io.h:106:53: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: arch/riscv/include/asm/io.h:118:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: arch/riscv/include/asm/io.h:119:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: arch/riscv/include/asm/io.h:120:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   clang diag: include/asm-generic/io.h:1175:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
>> error[E0433]: failed to resolve: could not find `mm` in the crate root
   --> rust/kernel/miscdevice.rs:17:5
   |
   17 |     mm::virt::VmaNew,
   |     ^^ could not find `mm` in the crate root
   |
   note: found an item that was configured out
   --> rust/kernel/lib.rs:64:9
   |
   64 | pub mod mm;
   |         ^^

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [linux-next:master 4752/5832] error[E0433]: failed to resolve: could not find `mm` in the crate root

[Alice Ryhl]

On Wed, May 7, 2025 at 11:29 AM kernel test robot <lkp@intel.com> wrote:
> >> error[E0433]: failed to resolve: could not find `mm` in the crate root
>    --> rust/kernel/miscdevice.rs:17:5
>    |
>    17 |     mm::virt::VmaNew,
>    |     ^^ could not find `mm` in the crate root
>    |
>    note: found an item that was configured out
>    --> rust/kernel/lib.rs:64:9
>    |
>    64 | pub mod mm;
>    |         ^^

This is because I ifdef'd out too much of the kernel::mm module with
CONFIG_MMU=n.

Please see this patch for a fix:
https://lore.kernel.org/all/20250508083540.3832900-1-aliceryhl@google.com/

Alice