Re: [PATCH v7 7/7] rust: enable `clippy::ref_as_ptr` lint

[kernel test robot <lkp@intel.com>]

Hi Tamir,

kernel test robot noticed the following build errors:

[auto build test ERROR on 28bb48c4cb34f65a9aa602142e76e1426da31293]

url:    https://github.com/intel-lab-lkp/linux/commits/Tamir-Duberstein/rust-retain-pointer-mut-ness-in-container_of/20250326-081159
base:   28bb48c4cb34f65a9aa602142e76e1426da31293
patch link:    https://lore.kernel.org/r/20250325-ptr-as-ptr-v7-7-87ab452147b9%40gmail.com
patch subject: [PATCH v7 7/7] rust: enable `clippy::ref_as_ptr` lint
config: x86_64-rhel-9.4-rust (https://download.01.org/0day-ci/archive/20250327/202503270730.qlrkmZkU-lkp@intel.com/config)
compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff)
rustc: rustc 1.78.0 (9b00956e5 2024-04-29)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250327/202503270730.qlrkmZkU-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/202503270730.qlrkmZkU-lkp@intel.com/

All errors (new ones prefixed by >>):

   PATH=/opt/cross/clang-18/bin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
   INFO PATH=/opt/cross/rustc-1.78.0-bindgen-0.65.1/cargo/bin:/opt/cross/clang-18/bin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
   /usr/bin/timeout -k 100 12h /usr/bin/make KCFLAGS= -Wno-error=return-type -Wreturn-type -funsigned-char -Wundef W=1 --keep-going LLVM=1 -j32 -C source O=/kbuild/obj/consumer/x86_64-rhel-9.4-rust ARCH=x86_64 SHELL=/bin/bash rustfmtcheck
   make: Entering directory '/kbuild/src/consumer'
   make[1]: Entering directory '/kbuild/obj/consumer/x86_64-rhel-9.4-rust'
>> Diff in rust/kernel/uaccess.rs at line 356:
            // kernel pointer. This mirrors the logic on the C side that skips the check when the length
            // is a compile-time constant.
            let res = unsafe {
   -            bindings::_copy_to_user(
   -                self.ptr as *mut c_void,
   -                value.cast::<c_void>(),
   -                len,
   -            )
   +            bindings::_copy_to_user(self.ptr as *mut c_void, value.cast::<c_void>(), len)
            };
            if res != 0 {
                return Err(EFAULT);
>> Diff in rust/kernel/uaccess.rs at line 356:
            // kernel pointer. This mirrors the logic on the C side that skips the check when the length
            // is a compile-time constant.
            let res = unsafe {
   -            bindings::_copy_to_user(
   -                self.ptr as *mut c_void,
   -                value.cast::<c_void>(),
   -                len,
   -            )
   +            bindings::_copy_to_user(self.ptr as *mut c_void, value.cast::<c_void>(), len)
            };
            if res != 0 {
                return Err(EFAULT);
   make[2]: *** [Makefile:1817: rustfmt] Error 123
   make[2]: Target 'rustfmtcheck' not remade because of errors.
   make[1]: Leaving directory '/kbuild/obj/consumer/x86_64-rhel-9.4-rust'
   make[1]: *** [Makefile:251: __sub-make] Error 2
   make[1]: Target 'rustfmtcheck' not remade because of errors.
   make: *** [Makefile:251: __sub-make] Error 2
   make: Target 'rustfmtcheck' not remade because of errors.
   make: Leaving directory '/kbuild/src/consumer'

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