7:52 p.m.
Le 12/05/2021 à 11:36, Christophe Leroy a écrit :
Le 11/05/2021 à 20:46, Nathan Chancellor a écrit :
> On 5/11/2021 9:47 AM, Christophe Leroy wrote:
>> Hi All,
>>
>> Le 11/05/2021 à 18:30, kernel test robot a écrit :
>>> Hi Christophe,
>>>
>>> First bad commit (maybe != root cause):
>>>
>>> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
master
>>> head: 1140ab592e2ebf8153d2b322604031a8868ce7a5
>>> commit: eacf4c0202654adfa94bbb17b5c5c77c0be14af8 powerpc: Enable OPTPROBES on
PPC32
Ok, the problem appears on PPC32 with that patch, but it must have been there on PPC64
since the
implementation of optprobes with commit 51c9c0843993 ("powerpc/kprobes: Implement
Optprobes")
>>> date: 3 weeks ago
>>> config: powerpc-randconfig-r033-20210511 (attached as .config)
>>> compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project
>>> a0fed635fe1701470062495a6ffee1c608f3f1bc)
>>
>> A clang issue ?
>>
>>
>>> 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 powerpc cross compiling tool for clang build
>>> # apt-get install binutils-powerpc-linux-gnu
>>> #
>>>
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit...
>>>
>>> git remote add linus
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>>> git fetch --no-tags linus master
>>> git checkout eacf4c0202654adfa94bbb17b5c5c77c0be14af8
>>> # save the attached .config to linux build tree
>>> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1
ARCH=powerpc
>>>
>>> If you fix the issue, kindly add following tag as appropriate
>>> Reported-by: kernel test robot <lkp(a)intel.com>
>>>
>>> All errors (new ones prefixed by >>):
>>>
>>>>> arch/powerpc/kernel/optprobes.c:34:1: error: unused function
'is_kprobe_ppc_optinsn_slot'
>>>>> [-Werror,-Wunused-function]
>>> DEFINE_INSN_CACHE_OPS(ppc_optinsn);
>>> ^
>>> include/linux/kprobes.h:306:20: note: expanded from macro
'DEFINE_INSN_CACHE_OPS'
>>> static inline bool is_kprobe_##__name##_slot(unsigned long addr)
\
>>
>> That's a 'static inline', shouldn't generate an 'unused
function' warning.
> This is a W=1 build, which means that "inline" does not silence unused
function warnings with
> clang because of commit 6863f5643dd7 ("kbuild: allow Clang to find unused static
inline functions
> for W=1 build").
Ok, I didn't know that.
After looking at it in more details, I don't really know what should be done to avoid
that.
This unused function is defined as part of DEFINE_INSN_CACHE_OPS(ppc_optinsn).
The code uses other items defined by macro DEFINE_INSN_CACHE_OPS, so it cannot be
removed.
Solution could be to hide that in a .h, but is that worth it ?
It can't go in asm/kprobes.h because linux/kprobes.h includes asm/kprobes.h before
defining
DEFINE_INSN_CACHE_OPS(). So it would mean a dedicated header just for hiding the problem
under the
carpet.
>
>>
>> Cheers,
>> Nathan
>>
>>>> ^
>>>> <scratch space>:16:1: note: expanded from here
>>>> is_kprobe_ppc_optinsn_slot
>>>> ^
>>>> 1 error generated.
>>>>
>>>>
>>>> vim +/is_kprobe_ppc_optinsn_slot +34 arch/powerpc/kernel/optprobes.c
>>>>
>>>> 51c9c084399352 Anju T 2017-02-08 20
>>>> 51c9c084399352 Anju T 2017-02-08 21 #define TMPL_CALL_HDLR_IDX \
>>>> 51c9c084399352 Anju T 2017-02-08 22 (optprobe_template_call_handler -
optprobe_template_entry)
>>>> 51c9c084399352 Anju T 2017-02-08 23 #define TMPL_EMULATE_IDX \
>>>> 51c9c084399352 Anju T 2017-02-08 24 (optprobe_template_call_emulate -
optprobe_template_entry)
>>>> 51c9c084399352 Anju T 2017-02-08 25 #define TMPL_RET_IDX \
>>>> 51c9c084399352 Anju T 2017-02-08 26 (optprobe_template_ret -
optprobe_template_entry)
>>>> 51c9c084399352 Anju T 2017-02-08 27 #define TMPL_OP_IDX \
>>>> 51c9c084399352 Anju T 2017-02-08 28 (optprobe_template_op_address -
optprobe_template_entry)
>>>> 51c9c084399352 Anju T 2017-02-08 29 #define TMPL_INSN_IDX \
>>>> 51c9c084399352 Anju T 2017-02-08 30 (optprobe_template_insn -
optprobe_template_entry)
>>>> 51c9c084399352 Anju T 2017-02-08 31 #define TMPL_END_IDX \
>>>> 51c9c084399352 Anju T 2017-02-08 32 (optprobe_template_end -
optprobe_template_entry)
>>>> 51c9c084399352 Anju T 2017-02-08 33
>>>> 51c9c084399352 Anju T 2017-02-08 @34
DEFINE_INSN_CACHE_OPS(ppc_optinsn);
>>>> 51c9c084399352 Anju T 2017-02-08 35
>>>>
>>>> :::::: The code at line 34 was first introduced by commit
>>>> :::::: 51c9c0843993528bffc920c54c2121d9e6f8b090 powerpc/kprobes:
Implement Optprobes
>>>>
>>>> :::::: TO: Anju T <anju(a)linux.vnet.ibm.com>
>>>> :::::: CC: Michael Ellerman <mpe(a)ellerman.id.au>
>>>>
>>>> ---
>>>> 0-DAY CI Kernel Test Service, Intel Corporation
>>>> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
>>>>
>>>