Re: [PATCH] arm64: add the printing of tpidr_elx in __show_regs()

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

Hi Zhen,

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 arm/for-next xilinx-xlnx/master soc/for-next kvmarm/next v5.17-rc8 next-20220315]
[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/Zhen-Lei/arm64-add-the-printing-of-tpidr_elx-in-__show_regs/20220315-191234
base:   https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
config: arm64-buildonly-randconfig-r002-20220313 (https://download.01.org/0day-ci/archive/20220316/202203160347.f7ls2XFW-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project a6b2f50fb47da3baeee10b1906da6e30ac5d26ec)
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 arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        # https://github.com/0day-ci/linux/commit/1a42e34104d70b0b90fe074ba96f2c04d33ffb23
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Zhen-Lei/arm64-add-the-printing-of-tpidr_elx-in-__show_regs/20220315-191234
        git checkout 1a42e34104d70b0b90fe074ba96f2c04d33ffb23
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash arch/arm64/kernel/

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

All warnings (new ones prefixed by >>):

>> arch/arm64/kernel/process.c:220:30: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
                   printk("tpidr : %016lx\n", this_cpu_ptr(NULL));
                                              ^~~~~~~~~~~~~~~~~~
   include/linux/printk.h:446:60: note: expanded from macro 'printk'
   #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__)
                                                              ^~~~~~~~~~~
   include/linux/printk.h:418:19: note: expanded from macro 'printk_index_wrap'
                   _p_func(_fmt, ##__VA_ARGS__);                           \
                                   ^~~~~~~~~~~
   include/linux/percpu-defs.h:252:27: note: expanded from macro 'this_cpu_ptr'
   #define this_cpu_ptr(ptr) raw_cpu_ptr(ptr)
                             ^~~~~~~~~~~~~~~~
   include/linux/percpu-defs.h:241:2: note: expanded from macro 'raw_cpu_ptr'
           __verify_pcpu_ptr(ptr);                                         \
           ^~~~~~~~~~~~~~~~~~~~~~
   include/linux/percpu-defs.h:219:52: note: expanded from macro '__verify_pcpu_ptr'
           const void __percpu *__vpp_verify = (typeof((ptr) + 0))NULL;    \
                                                       ~~~~~ ^
>> arch/arm64/kernel/process.c:220:30: warning: format specifies type 'unsigned long' but the argument has type 'typeof (*(((void *)0))) *' (aka 'void *') [-Wformat]
                   printk("tpidr : %016lx\n", this_cpu_ptr(NULL));
                                   ~~~~~~     ^~~~~~~~~~~~~~~~~~
   include/linux/printk.h:446:60: note: expanded from macro 'printk'
   #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__)
                                                       ~~~    ^~~~~~~~~~~
   include/linux/printk.h:418:19: note: expanded from macro 'printk_index_wrap'
                   _p_func(_fmt, ##__VA_ARGS__);                           \
                           ~~~~    ^~~~~~~~~~~
   include/linux/percpu-defs.h:252:27: note: expanded from macro 'this_cpu_ptr'
   #define this_cpu_ptr(ptr) raw_cpu_ptr(ptr)
                             ^~~~~~~~~~~~~~~~
   include/linux/percpu-defs.h:239:31: note: expanded from macro 'raw_cpu_ptr'
   #define raw_cpu_ptr(ptr)                                                \
                                                                           ^
   2 warnings generated.


vim +220 arch/arm64/kernel/process.c

   200	
   201	void __show_regs(struct pt_regs *regs)
   202	{
   203		int i, top_reg;
   204		u64 lr, sp;
   205	
   206		if (compat_user_mode(regs)) {
   207			lr = regs->compat_lr;
   208			sp = regs->compat_sp;
   209			top_reg = 12;
   210		} else {
   211			lr = regs->regs[30];
   212			sp = regs->sp;
   213			top_reg = 29;
   214		}
   215	
   216		show_regs_print_info(KERN_DEFAULT);
   217		print_pstate(regs);
   218	
   219		if (IS_ENABLED(CONFIG_SMP))
 > 220			printk("tpidr : %016lx\n", this_cpu_ptr(NULL));
   221	
   222		if (!user_mode(regs)) {
   223			printk("pc : %pS\n", (void *)regs->pc);
   224			printk("lr : %pS\n", (void *)ptrauth_strip_insn_pac(lr));
   225		} else {
   226			printk("pc : %016llx\n", regs->pc);
   227			printk("lr : %016llx\n", lr);
   228		}
   229	
   230		printk("sp : %016llx\n", sp);
   231	
   232		if (system_uses_irq_prio_masking())
   233			printk("pmr_save: %08llx\n", regs->pmr_save);
   234	
   235		i = top_reg;
   236	
   237		while (i >= 0) {
   238			printk("x%-2d: %016llx", i, regs->regs[i]);
   239	
   240			while (i-- % 3)
   241				pr_cont(" x%-2d: %016llx", i, regs->regs[i]);
   242	
   243			pr_cont("\n");
   244		}
   245	}
   246	

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