Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <202210072120.V1O2SuKY-lkp@intel.com>
In-Reply-To: <202210072120.V1O2SuKY-lkp@intel.com>
From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Mon, 10 Oct 2022 10:03:40 -0700
Message-ID: <CAKwvOd=CgD0xaUA4sUqbofJjA2x_peOuVh=YTV_GuiUNNTjACA@mail.gmail.com>
Subject: Re: arch/arm/include/asm/xor.h:60:3: error: write to reserved
 register 'R7'
To:     kernel test robot <lkp@intel.com>
Cc:     Ard Biesheuvel <ardb@kernel.org>, llvm@lists.linux.dev,
        kbuild-all@lists.01.org, linux-kernel@vger.kernel.org,
        "Steven Rostedt (Google)" <rostedt@goodmis.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Fri, Oct 7, 2022 at 6:16 AM kernel test robot <lkp@intel.com> wrote:
>
> Hi Ard,
>
> FYI, the error/warning was bisected to this commit, please ignore it if it's irrelevant.

Thanks for the report. Filed
https://github.com/ClangBuiltLinux/linux/issues/1732
to follow up on this.

>
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   4c86114194e644b6da9107d75910635c9e87179e
> commit: d6800ca73a7d325627c045c16d7cfdc7465f4333 Revert "ARM: 9144/1: forbid ftrace with clang and thumb2_kernel"
> date:   8 months ago
> config: arm-randconfig-r013-20221007
> compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 791a7ae1ba3efd6bca96338e10ffde557ba83920)
> 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 arm cross compiling tool for clang build
>         # apt-get install binutils-arm-linux-gnueabi
>         # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d6800ca73a7d325627c045c16d7cfdc7465f4333
>         git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>         git fetch --no-tags linus master
>         git checkout d6800ca73a7d325627c045c16d7cfdc7465f4333
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash
>
> If you fix the issue, kindly add following tag where applicable
> | Reported-by: kernel test robot <lkp@intel.com>
>
> All errors (new ones prefixed by >>):
>
>    In file included from crypto/xor.c:17:
> >> arch/arm/include/asm/xor.h:60:3: error: write to reserved register 'R7'
>                    GET_BLOCK_4(p1);
>                    ^
>    arch/arm/include/asm/xor.h:20:10: note: expanded from macro 'GET_BLOCK_4'
>            __asm__("ldmia  %0, {%1, %2, %3, %4}" \
>                    ^
>    arch/arm/include/asm/xor.h:62:3: error: write to reserved register 'R7'
>                    PUT_BLOCK_4(p1);
>                    ^
>    arch/arm/include/asm/xor.h:42:23: note: expanded from macro 'PUT_BLOCK_4'
>            __asm__ __volatile__("stmia     %0!, {%2, %3, %4, %5}" \
>                                 ^
>    arch/arm/include/asm/xor.h:81:3: error: write to reserved register 'R7'
>                    GET_BLOCK_4(p1);
>                    ^
>    arch/arm/include/asm/xor.h:20:10: note: expanded from macro 'GET_BLOCK_4'
>            __asm__("ldmia  %0, {%1, %2, %3, %4}" \
>                    ^
>    arch/arm/include/asm/xor.h:84:3: error: write to reserved register 'R7'
>                    PUT_BLOCK_4(p1);
>                    ^
>    arch/arm/include/asm/xor.h:42:23: note: expanded from macro 'PUT_BLOCK_4'
>            __asm__ __volatile__("stmia     %0!, {%2, %3, %4, %5}" \
>                                 ^
>    4 errors generated.
>
>
> vim +/R7 +60 arch/arm/include/asm/xor.h
>
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  13
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  14  #define GET_BLOCK_2(dst) \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  15      __asm__("ldmia  %0, {%1, %2}" \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  16              : "=r" (dst), "=r" (a1), "=r" (a2) \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  17              : "0" (dst))
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  18
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  19  #define GET_BLOCK_4(dst) \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  20      __asm__("ldmia  %0, {%1, %2, %3, %4}" \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  21              : "=r" (dst), "=r" (a1), "=r" (a2), "=r" (a3), "=r" (a4) \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  22              : "0" (dst))
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  23
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  24  #define XOR_BLOCK_2(src) \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  25      __asm__("ldmia  %0!, {%1, %2}" \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  26              : "=r" (src), "=r" (b1), "=r" (b2) \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  27              : "0" (src)); \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  28      __XOR(a1, b1); __XOR(a2, b2);
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  29
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  30  #define XOR_BLOCK_4(src) \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  31      __asm__("ldmia  %0!, {%1, %2, %3, %4}" \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  32              : "=r" (src), "=r" (b1), "=r" (b2), "=r" (b3), "=r" (b4) \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  33              : "0" (src)); \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  34      __XOR(a1, b1); __XOR(a2, b2); __XOR(a3, b3); __XOR(a4, b4)
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  35
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  36  #define PUT_BLOCK_2(dst) \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  37      __asm__ __volatile__("stmia     %0!, {%2, %3}" \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  38              : "=r" (dst) \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  39              : "0" (dst), "r" (a1), "r" (a2))
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  40
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  41  #define PUT_BLOCK_4(dst) \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  42      __asm__ __volatile__("stmia     %0!, {%2, %3, %4, %5}" \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  43              : "=r" (dst) \
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  44              : "0" (dst), "r" (a1), "r" (a2), "r" (a3), "r" (a4))
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  45
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  46  static void
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  47  xor_arm4regs_2(unsigned long bytes, unsigned long *p1, unsigned long *p2)
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  48  {
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  49      unsigned int lines = bytes / sizeof(unsigned long) / 4;
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  50      register unsigned int a1 __asm__("r4");
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  51      register unsigned int a2 __asm__("r5");
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  52      register unsigned int a3 __asm__("r6");
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  53      register unsigned int a4 __asm__("r7");
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  54      register unsigned int b1 __asm__("r8");
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  55      register unsigned int b2 __asm__("r9");
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  56      register unsigned int b3 __asm__("ip");
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  57      register unsigned int b4 __asm__("lr");
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  58
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  59      do {
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16 @60              GET_BLOCK_4(p1);
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  61              XOR_BLOCK_4(p2);
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  62              PUT_BLOCK_4(p1);
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  63      } while (--lines);
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  64  }
> ^1da177e4c3f41 include/asm-arm/xor.h Linus Torvalds 2005-04-16  65
>
> :::::: The code at line 60 was first introduced by commit
> :::::: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Linux-2.6.12-rc2
>
> :::::: TO: Linus Torvalds <torvalds@ppc970.osdl.org>
> :::::: CC: Linus Torvalds <torvalds@ppc970.osdl.org>
>
> --
> 0-DAY CI Kernel Test Service
> https://01.org/lkp


-- 
Thanks,
~Nick Desaulniers