Re: arch/arm64/kvm/perf.c:58:36: error: implicit declaration of function 'perf_num_counters'
Hi,
On 4/13/21 9:00 PM, Nathan Chancellor wrote:
> On Fri, Mar 26, 2021 at 08:27:13PM +0800, kernel test robot wrote:
>> Hi Marc,
>>
>> FYI, the error/warning still remains.
>>
>> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>> master
>> head: db24726bfefa68c606947a86132591568a06bfb4
>> commit: 6b5b368fccd7109b052e45af8ba1464c8d140a49 KVM: arm64: Turn
>> kvm_arm_support_pmu_v3() into a static key
>> date: 3 weeks ago
>> config: arm64-randconfig-r005-20210326 (attached as .config)
>> compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project
>> f490a5969bd52c8a48586f134ff8f02ccbb295b3)
>> 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://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6b5b368fccd7109b052e45af8ba1464c8d140a49
>> git remote add linus
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>> git fetch --no-tags linus master
>> git checkout 6b5b368fccd7109b052e45af8ba1464c8d140a49
>> # save the attached .config to linux build tree
>> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross
>> ARCH=arm64
>>
>> If you fix the issue, kindly add following tag as appropriate
>> Reported-by: kernel test robot
>>
>> All errors (new ones prefixed by >>):
>>
>>>> arch/arm64/kvm/perf.c:58:36: error: implicit declaration of function
>>>> 'perf_num_counters' [-Werror,-Wimplicit-function-declaration]
>>if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() > 0)
>> ^
>>1 error generated.
>>
>>
>> vim +/perf_num_counters +58 arch/arm64/kvm/perf.c
>>
>> 50
>> 51 int kvm_perf_init(void)
>> 52 {
>> 53 /*
>> 54* Check if HW_PERF_EVENTS are supported by checking
>> the number of
>> 55* hardware performance counters. This could ensure the
>> presence of
>> 56* a physical PMU and CONFIG_PERF_EVENT is selected.
>> 57*/
>> > 58 if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() >
>> 0)
>> 59 static_branch_enable(_arm_pmu_available);
>> 60
>> 61 return
>> perf_register_guest_info_callbacks(_guest_cbs);
>> 62 }
>> 63
>>
>> ---
>> 0-DAY CI Kernel Test Service, Intel Corporation
>> https://lists.01.org/hyperkitty/list/kbuild-...@lists.01.org
> I just ran into this again. It is not a clang specific issue, it
> reproduces quite easily with arm64 defconfig minus CONFIG_PERF_EVENTS
> and gcc 10.3.0:
>
> arch/arm64/kvm/perf.c: In function 'kvm_perf_init':
> arch/arm64/kvm/perf.c:58:36: error: implicit declaration of function
> 'perf_num_counters'; did you mean 'dec_mm_counter'?
> [-Werror=implicit-function-declaration]
>58 | if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() > 0)
> |^
> |dec_mm_counter
> cc1: some warnings being treated as errors
I was also able to reproduce it with gcc 10.2.0. I think the problem is that the
perf_num_counters() declaration is guarded by CONFIG_PERF_EVENTS (in
include/linux/perf_event.h), the implementation is in drivers/perf/arm_pmu.c,
which depends on CONFIG_ARM_PMU, but CONFIG_ARM_PMU=y doesn't select
CONFIG_PERF_EVENTS. So we end up in a situation where we have the implementation
of perf_num_counters(), but no prototype (CONFIG_ARM_PMU=y, CONFIG_PERF_EVENTS
is
not set).
Thanks,
Alex
>
> I am not sure what the cleanest solution would be for providing a static
> inline version of perf_num_counters() would be, as only arm64 actually
> uses it (sh and s390 define it but it does not appear to be used) but it
> is only available through CONFIG_ARM_PMU instead of just
> CONFIG_PERF_EVENTS like the other two architectures mentioned above.
>
> Cheers,
> Nathan
Re: arch/arm64/kvm/perf.c:58:36: error: implicit declaration of function 'perf_num_counters'
On Tue, 13 Apr 2021 21:00:57 +0100, Nathan Chancellor wrote: [...] > I just ran into this again. It is not a clang specific issue, it > reproduces quite easily with arm64 defconfig minus CONFIG_PERF_EVENTS > and gcc 10.3.0: > > arch/arm64/kvm/perf.c: In function 'kvm_perf_init': > arch/arm64/kvm/perf.c:58:36: error: implicit declaration of function > 'perf_num_counters'; did you mean 'dec_mm_counter'? > [-Werror=implicit-function-declaration] >58 | if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() > 0) > |^ > |dec_mm_counter > cc1: some warnings being treated as errors > > I am not sure what the cleanest solution would be for providing a static > inline version of perf_num_counters() would be, as only arm64 actually > uses it (sh and s390 define it but it does not appear to be used) but it > is only available through CONFIG_ARM_PMU instead of just > CONFIG_PERF_EVENTS like the other two architectures mentioned above. As you point out, KVM/arm64 is the only user of perf_num_counters() across the whole kernel. The whole oprofile subsystem has been removed, so maybe a a bigger cleanup is in order. I'll post something shortly. Thanks, M. -- Without deviation from the norm, progress is not possible.
Re: arch/arm64/kvm/perf.c:58:36: error: implicit declaration of function 'perf_num_counters'
On Fri, Mar 26, 2021 at 08:27:13PM +0800, kernel test robot wrote:
> Hi Marc,
>
> FYI, the error/warning still remains.
>
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> master
> head: db24726bfefa68c606947a86132591568a06bfb4
> commit: 6b5b368fccd7109b052e45af8ba1464c8d140a49 KVM: arm64: Turn
> kvm_arm_support_pmu_v3() into a static key
> date: 3 weeks ago
> config: arm64-randconfig-r005-20210326 (attached as .config)
> compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project
> f490a5969bd52c8a48586f134ff8f02ccbb295b3)
> 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://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6b5b368fccd7109b052e45af8ba1464c8d140a49
> git remote add linus
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> git fetch --no-tags linus master
> git checkout 6b5b368fccd7109b052e45af8ba1464c8d140a49
> # save the attached .config to linux build tree
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot
>
> All errors (new ones prefixed by >>):
>
> >> arch/arm64/kvm/perf.c:58:36: error: implicit declaration of function
> >> 'perf_num_counters' [-Werror,-Wimplicit-function-declaration]
>if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() > 0)
> ^
>1 error generated.
>
>
> vim +/perf_num_counters +58 arch/arm64/kvm/perf.c
>
> 50
> 51int kvm_perf_init(void)
> 52{
> 53/*
> 54 * Check if HW_PERF_EVENTS are supported by checking
> the number of
> 55 * hardware performance counters. This could ensure the
> presence of
> 56 * a physical PMU and CONFIG_PERF_EVENT is selected.
> 57 */
> > 58if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() >
> 0)
> 59static_branch_enable(_arm_pmu_available);
> 60
> 61return
> perf_register_guest_info_callbacks(_guest_cbs);
> 62}
> 63
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-...@lists.01.org
I just ran into this again. It is not a clang specific issue, it
reproduces quite easily with arm64 defconfig minus CONFIG_PERF_EVENTS
and gcc 10.3.0:
arch/arm64/kvm/perf.c: In function 'kvm_perf_init':
arch/arm64/kvm/perf.c:58:36: error: implicit declaration of function
'perf_num_counters'; did you mean 'dec_mm_counter'?
[-Werror=implicit-function-declaration]
58 | if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() > 0)
|^
|dec_mm_counter
cc1: some warnings being treated as errors
I am not sure what the cleanest solution would be for providing a static
inline version of perf_num_counters() would be, as only arm64 actually
uses it (sh and s390 define it but it does not appear to be used) but it
is only available through CONFIG_ARM_PMU instead of just
CONFIG_PERF_EVENTS like the other two architectures mentioned above.
Cheers,
Nathan
arch/arm64/kvm/perf.c:58:36: error: implicit declaration of function 'perf_num_counters'
Hi Marc,
FYI, the error/warning still remains.
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
master
head: db24726bfefa68c606947a86132591568a06bfb4
commit: 6b5b368fccd7109b052e45af8ba1464c8d140a49 KVM: arm64: Turn
kvm_arm_support_pmu_v3() into a static key
date: 3 weeks ago
config: arm64-randconfig-r005-20210326 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project
f490a5969bd52c8a48586f134ff8f02ccbb295b3)
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://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6b5b368fccd7109b052e45af8ba1464c8d140a49
git remote add linus
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 6b5b368fccd7109b052e45af8ba1464c8d140a49
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot
All errors (new ones prefixed by >>):
>> arch/arm64/kvm/perf.c:58:36: error: implicit declaration of function
>> 'perf_num_counters' [-Werror,-Wimplicit-function-declaration]
if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() > 0)
^
1 error generated.
vim +/perf_num_counters +58 arch/arm64/kvm/perf.c
50
51 int kvm_perf_init(void)
52 {
53 /*
54 * Check if HW_PERF_EVENTS are supported by checking the number
of
55 * hardware performance counters. This could ensure the
presence of
56 * a physical PMU and CONFIG_PERF_EVENT is selected.
57 */
> 58 if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() > 0)
59 static_branch_enable(_arm_pmu_available);
60
61 return perf_register_guest_info_callbacks(_guest_cbs);
62 }
63
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-...@lists.01.org
.config.gz
Description: application/gzip
arch/arm64/kvm/perf.c:58:36: error: implicit declaration of function 'perf_num_counters'
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
master
head: db24726bfefa68c606947a86132591568a06bfb4
commit: 6b5b368fccd7109b052e45af8ba1464c8d140a49 KVM: arm64: Turn
kvm_arm_support_pmu_v3() into a static key
date: 3 weeks ago
config: arm64-randconfig-r005-20210326 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project
f490a5969bd52c8a48586f134ff8f02ccbb295b3)
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://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6b5b368fccd7109b052e45af8ba1464c8d140a49
git remote add linus
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 6b5b368fccd7109b052e45af8ba1464c8d140a49
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot
All errors (new ones prefixed by >>):
>> arch/arm64/kvm/perf.c:58:36: error: implicit declaration of function
>> 'perf_num_counters' [-Werror,-Wimplicit-function-declaration]
if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() > 0)
^
1 error generated.
vim +/perf_num_counters +58 arch/arm64/kvm/perf.c
50
51 int kvm_perf_init(void)
52 {
53 /*
54 * Check if HW_PERF_EVENTS are supported by checking the number
of
55 * hardware performance counters. This could ensure the
presence of
56 * a physical PMU and CONFIG_PERF_EVENT is selected.
57 */
> 58 if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() > 0)
59 static_branch_enable(_arm_pmu_available);
60
61 return perf_register_guest_info_callbacks(_guest_cbs);
62 }
63
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-...@lists.01.org
.config.gz
Description: application/gzip
