Re: [PATCH v2 4/4] coresight: etm3x: Don't trace PID for non-root PID namespace

[Rong Chen <rong.a.chen@intel.com>]

On 12/14/21 12:46, Leo Yan wrote:
> Hi,
>
> On Tue, Dec 14, 2021 at 03:16:42AM +0800, kernel test robot wrote:
>> Hi Leo,
>>
>> I love your patch! Yet something to improve:
>>
>> [auto build test ERROR on linus/master]
>> [also build test ERROR on v5.16-rc5]
>> [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/Leo-Yan/coresight-etm-Correct-PID-tracing-for-non-root-namespace/20211213-201632
>> base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 2585cf9dfaaddf00b069673f27bb3f8530e2039c
>> config: arm-buildonly-randconfig-r003-20211213 (https://download.01.org/0day-ci/archive/20211214/202112140344.viPmOWp6-lkp@intel.com/config)
>> compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project b6a2ddb6c8ac29412b1361810972e15221fa021c)
>> 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 arm cross compiling tool for clang build
>>          # apt-get install binutils-arm-linux-gnueabi
>>          # https://github.com/0day-ci/linux/commit/81d5f47788c40d34c8159d64d4505eb485254e8f
>>          git remote add linux-review https://github.com/0day-ci/linux
>>          git fetch --no-tags linux-review Leo-Yan/coresight-etm-Correct-PID-tracing-for-non-root-namespace/20211213-201632
>>          git checkout 81d5f47788c40d34c8159d64d4505eb485254e8f
>>          # 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=arm SHELL=/bin/bash drivers/hwtracing/coresight/
>>
>> If you fix the issue, kindly add following tag as appropriate
>> Reported-by: kernel test robot <lkp@intel.com>
>>
>> All errors (new ones prefixed by >>):
>>
>>>> drivers/hwtracing/coresight/coresight-etm3x-core.c:344:7: error: implicit declaration of function 'task_is_in_init_pid_ns' [-Werror,-Wimplicit-function-declaration]
>>             if (!task_is_in_init_pid_ns(current))
>>                  ^
>>     1 error generated.
>>
>>
>> vim +/task_is_in_init_pid_ns +344 drivers/hwtracing/coresight/coresight-etm3x-core.c
>>
>>     301	
>>     302	#define ETM3X_SUPPORTED_OPTIONS (ETMCR_CYC_ACC | \
>>     303					 ETMCR_TIMESTAMP_EN | \
>>     304					 ETMCR_RETURN_STACK)
>>     305	
>>     306	static int etm_parse_event_config(struct etm_drvdata *drvdata,
>>     307					  struct perf_event *event)
>>     308	{
>>     309		struct etm_config *config = &drvdata->config;
>>     310		struct perf_event_attr *attr = &event->attr;
>>     311	
>>     312		if (!attr)
>>     313			return -EINVAL;
>>     314	
>>     315		/* Clear configuration from previous run */
>>     316		memset(config, 0, sizeof(struct etm_config));
>>     317	
>>     318		if (attr->exclude_kernel)
>>     319			config->mode = ETM_MODE_EXCL_KERN;
>>     320	
>>     321		if (attr->exclude_user)
>>     322			config->mode = ETM_MODE_EXCL_USER;
>>     323	
>>     324		/* Always start from the default config */
>>     325		etm_set_default(config);
>>     326	
>>     327		/*
>>     328		 * By default the tracers are configured to trace the whole address
>>     329		 * range.  Narrow the field only if requested by user space.
>>     330		 */
>>     331		if (config->mode)
>>     332			etm_config_trace_mode(config);
>>     333	
>>     334		/*
>>     335		 * At this time only cycle accurate, return stack  and timestamp
>>     336		 * options are available.
>>     337		 */
>>     338		if (attr->config & ~ETM3X_SUPPORTED_OPTIONS)
>>     339			return -EINVAL;
>>     340	
>>     341		config->ctrl = attr->config;
>>     342	
>>     343		/* Don't trace contextID when runs in non-root PID namespace */
>>   > 344		if (!task_is_in_init_pid_ns(current))
> This patchset is based on another patchset [1], as described on the
> cover letter patch.  This is why here reports for building failure.
>
> To avoid the false positive reporting, if any better practice I can
> follow up to resolve the dependency between two patchsets, please let
> me know and I will do in next time.

Hi Leo,

Sorry for the inconvenience, the bot doesn't support to parse the link 
in cover letter yet,
we suggest to use '--base' as documented 
inhttps://git-scm.com/docs/git-format-patch

Best Regards,
Rong CHen

>
> Thanks,
> Leo
>
> [1] https://lore.kernel.org/lkml/20211208083320.472503-1-leo.yan@linaro.org/
>
>>     345			config->ctrl &= ~ETMCR_CTXID_SIZE;
>>     346	
>>     347		/*
>>     348		 * Possible to have cores with PTM (supports ret stack) and ETM
>>     349		 * (never has ret stack) on the same SoC. So if we have a request
>>     350		 * for return stack that can't be honoured on this core then
>>     351		 * clear the bit - trace will still continue normally
>>     352		 */
>>     353		if ((config->ctrl & ETMCR_RETURN_STACK) &&
>>     354		    !(drvdata->etmccer & ETMCCER_RETSTACK))
>>     355			config->ctrl &= ~ETMCR_RETURN_STACK;
>>     356	
>>     357		return 0;
>>     358	}
>>     359	
>>
>> ---
>> 0-DAY CI Kernel Test Service, Intel Corporation
>> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org