tree:   git://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git for-kernelci
head:   f7296306098662beeec45001fb949d2f9f4239d3
commit: 81de60b03a22a36ab920948a6584aa6ec05fe88f [16/19] ARM: memcpy: use frame pointer as unwind anchor
config: arm-buildonly-randconfig-r002-20211008 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 30caca39f401ae17927439c0a0bd6d1b1916dd6a)
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/ardb/linux.git/commit/?id=81de60b03a22a36ab920948a6584aa6ec05fe88f
        git remote add ardb git://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git
        git fetch --no-tags ardb for-kernelci
        git checkout 81de60b03a22a36ab920948a6584aa6ec05fe88f
        # save the attached .config to linux build tree
        mkdir build_dir
        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 as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> arch/arm/lib/call_with_stack.S:36:13: error: redefinition of 'fpreg' does not match original.
    fpreg .req r7
               ^


vim +/fpreg +36 arch/arm/lib/call_with_stack.S

2d81f1fe81b753 Will Deacon    2011-06-08  12  
2d81f1fe81b753 Will Deacon    2011-06-08  13  /*
2d81f1fe81b753 Will Deacon    2011-06-08  14   * void call_with_stack(void (*fn)(void *), void *arg, void *sp)
2d81f1fe81b753 Will Deacon    2011-06-08  15   *
2d81f1fe81b753 Will Deacon    2011-06-08  16   * Change the stack to that pointed at by sp, then invoke fn(arg) with
2d81f1fe81b753 Will Deacon    2011-06-08  17   * the new stack.
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  18   *
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  19   * The sequence below follows the APCS frame convention for frame pointer
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  20   * unwinding, and implements the unwinder annotations needed by the EABI
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  21   * unwinder.
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  22   */
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  23  
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  24  #if defined(CONFIG_THUMB2_KERNEL) || \
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  25      (defined(CONFIG_UNWINDER_FRAME_POINTER) && defined(CONFIG_CC_IS_CLANG))
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  26  /*
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  27   * Thumb-2 builds must use R7 as the frame pointer due to the way our unwind
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  28   * info based unwinder is constructed.
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  29   *
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  30   * The code below uses the GCC idiom for managing the frame pointer in the
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  31   * function prologue and epilogue, which Clang does not support. So the best we
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  32   * can do here is not touch the frame pointer at all: this will simply omit
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  33   * this frame when unwinding the call stack. So use R7 in this case as well,
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  34   * and leave R11 unmodified.
2d81f1fe81b753 Will Deacon    2011-06-08  35   */
e45123e7f2f5fd Ard Biesheuvel 2021-09-17 @36  	fpreg	.req	r7
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  37  #else
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  38  	fpreg	.req	fp
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  39  #endif
e45123e7f2f5fd Ard Biesheuvel 2021-09-17  40  

:::::: The code at line 36 was first introduced by commit
:::::: e45123e7f2f5fd88d16a53e80d13cfe181a74901 ARM: call_with_stack: add unwind support

:::::: TO: Ard Biesheuvel <ardb@kernel.org>
:::::: CC: Ard Biesheuvel <ardb@kernel.org>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org