Hi Liam,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on arm64/for-next/core]
[also build test WARNING on arm-perf/for-next/perf xlnx/master arm/for-next 
soc/for-next kvmarm/next linus/master v5.12-rc8 next-20210420]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    
https://github.com/0day-ci/linux/commits/Liam-Howlett/arm64-armv8_deprecated-Fix-swp_handler-signal-generation/20210421-005252
base:   https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git 
for-next/core
config: arm64-allyesconfig (attached as .config)
compiler: aarch64-linux-gcc (GCC) 9.3.0
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
        # 
https://github.com/0day-ci/linux/commit/96a011695861072d32851ba3a104b19106955869
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review 
Liam-Howlett/arm64-armv8_deprecated-Fix-swp_handler-signal-generation/20210421-005252
        git checkout 96a011695861072d32851ba3a104b19106955869
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross W=1 
ARCH=arm64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <l...@intel.com>

All warnings (new ones prefixed by >>):

   arch/arm64/kernel/armv8_deprecated.c: In function 'swp_handler':
>> arch/arm64/kernel/armv8_deprecated.c:418:11: warning: suggest parentheses 
>> around assignment used as truth value [-Wparentheses]
     418 |  else if (res = -ENXIO) /* Unaligned pointer */
         |           ^~~


vim +418 arch/arm64/kernel/armv8_deprecated.c

   365  
   366  /*
   367   * swp_handler logs the id of calling process, dissects the 
instruction, sanity
   368   * checks the memory location, calls emulate_swpX for the actual 
operation and
   369   * deals with fixup/error handling before returning
   370   */
   371  static int swp_handler(struct pt_regs *regs, u32 instr)
   372  {
   373          u32 destreg, data, type, address = 0;
   374          const void __user *user_ptr;
   375          int rn, rt2, res = 0;
   376  
   377          perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 
regs->pc);
   378  
   379          type = instr & TYPE_SWPB;
   380  
   381          switch (aarch32_check_condition(instr, regs->pstate)) {
   382          case ARM_OPCODE_CONDTEST_PASS:
   383                  break;
   384          case ARM_OPCODE_CONDTEST_FAIL:
   385                  /* Condition failed - return to next instruction */
   386                  goto ret;
   387          case ARM_OPCODE_CONDTEST_UNCOND:
   388                  /* If unconditional encoding - not a SWP, undef */
   389                  return -EFAULT;
   390          default:
   391                  return -EINVAL;
   392          }
   393  
   394          rn = aarch32_insn_extract_reg_num(instr, A32_RN_OFFSET);
   395          rt2 = aarch32_insn_extract_reg_num(instr, A32_RT2_OFFSET);
   396  
   397          address = (u32)regs->user_regs.regs[rn];
   398          data    = (u32)regs->user_regs.regs[rt2];
   399          destreg = aarch32_insn_extract_reg_num(instr, A32_RT_OFFSET);
   400  
   401          pr_debug("addr in r%d->0x%08x, dest is r%d, source in 
r%d->0x%08x)\n",
   402                  rn, address, destreg,
   403                  aarch32_insn_extract_reg_num(instr, A32_RT2_OFFSET), 
data);
   404  
   405          /* Check access in reasonable access range for both SWP and 
SWPB */
   406          user_ptr = (const void __user *)(unsigned long)(address & ~3);
   407          if (!access_ok(user_ptr, 4)) {
   408                  pr_debug("SWP{B} emulation: access to 0x%08x not 
allowed!\n",
   409                           address);
   410                  goto e_access;
   411          }
   412  
   413          res = emulate_swpX(address, &data, type);
   414          if (!res)
   415                  regs->user_regs.regs[destreg] = data;
   416          else if (res == -EFAULT)
   417                  goto e_fault;
 > 418          else if (res = -ENXIO) /* Unaligned pointer */
   419                  goto e_align;
   420  
   421  ret:
   422          if (type == TYPE_SWPB)
   423                  trace_instruction_emulation("swpb", regs->pc);
   424          else
   425                  trace_instruction_emulation("swp", regs->pc);
   426  
   427          pr_warn_ratelimited("\"%s\" (%ld) uses obsolete SWP{B} 
instruction at 0x%llx\n",
   428                          current->comm, (unsigned long)current->pid, 
regs->pc);
   429  
   430          arm64_skip_faulting_instruction(regs, 4);
   431          return 0;
   432  
   433  e_fault:
   434          pr_debug("SWP{B} emulation: access caused memory abort!\n");
   435          arm64_notify_segfault(address);
   436          return 0;
   437  
   438  e_align:
   439  e_access:
   440          force_signal_inject(SIGSEGV, SEGV_ACCERR, address, 0);
   441          return 0;
   442  }
   443  

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

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