Re: [PATCH 1/3] powerpc/ftrace: Reserve instructions from function entry for ftrace

From: kernel test robot
Date: Thu Feb 17 2022 - 14:47:17 EST


Hi "Naveen,

I love your patch! Perhaps something to improve:

[auto build test WARNING on 1b43a74f255c5c00db25a5fedfd75ca0dc029022]

url: https://github.com/0day-ci/linux/commits/Naveen-N-Rao/powerpc-ftrace-Reserve-instructions-from-function-entry-for-ftrace/20220217-200314
base: 1b43a74f255c5c00db25a5fedfd75ca0dc029022
config: powerpc-allyesconfig (https://download.01.org/0day-ci/archive/20220218/202202180014.IWuzQ9al-lkp@xxxxxxxxx/config)
compiler: powerpc-linux-gcc (GCC) 11.2.0
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/6a1891335e377e5def312e7c182aef676f04c926
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Naveen-N-Rao/powerpc-ftrace-Reserve-instructions-from-function-entry-for-ftrace/20220217-200314
git checkout 6a1891335e377e5def312e7c182aef676f04c926
# save the config file to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=powerpc SHELL=/bin/bash arch/powerpc/kernel/trace/

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

All warnings (new ones prefixed by >>):

>> arch/powerpc/kernel/trace/ftrace.c:504:5: warning: no previous prototype for 'ftrace_location_get_offset' [-Wmissing-prototypes]
504 | int ftrace_location_get_offset(const struct dyn_ftrace *rec)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/ftrace_location_get_offset +504 arch/powerpc/kernel/trace/ftrace.c

502
503 #if defined(CONFIG_MPROFILE_KERNEL) || defined(CONFIG_PPC32)
> 504 int ftrace_location_get_offset(const struct dyn_ftrace *rec)
505 {
506 if (IS_ENABLED(CONFIG_MPROFILE_KERNEL))
507 /*
508 * On ppc64le with -mprofile-kernel, function entry can have:
509 * addis r2, r12, M
510 * addi r2, r2, N
511 * mflr r0
512 * bl _mcount
513 *
514 * The first two instructions are for TOC setup and represent the global entry
515 * point for cross-module calls, and may be missing if the function is never called
516 * from other modules.
517 */
518 return ((unsigned long)rec->arch.mod & 0x1) ? FUNC_MCOUNT_OFFSET_PPC64_GEP :
519 FUNC_MCOUNT_OFFSET_PPC64_LEP;
520 else
521 /*
522 * On ppc32, function entry always has:
523 * mflr r0
524 * stw r0, 4(r1)
525 * bl _mcount
526 */
527 return FUNC_MCOUNT_OFFSET_PPC32;
528 }
529

---
0-DAY CI Kernel Test Service, Intel Corporation
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