Re: [RFC v1 1/4] nvmet-trace: avoid dereferencing pointer too early

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

Hi Daniel,

[This is a private test report for your RFC patch.]
kernel test robot noticed the following build warnings:

[auto build test WARNING on hch-configfs/for-next]
[also build test WARNING on linus/master v6.5 next-20230829]
[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#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Daniel-Wagner/nvmet-trace-avoid-dereferencing-pointer-too-early/20230829-171734
base:   git://git.infradead.org/users/hch/configfs.git for-next
patch link:    https://lore.kernel.org/r/20230829091350.16156-2-dwagner%40suse.de
patch subject: [RFC v1 1/4] nvmet-trace: avoid dereferencing pointer too early
config: sparc-allyesconfig (https://download.01.org/0day-ci/archive/20230829/202308291952.LKh4QF9k-lkp@intel.com/config)
compiler: sparc64-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230829/202308291952.LKh4QF9k-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308291952.LKh4QF9k-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/nvme/target/trace.c:214:13: warning: no previous prototype for 'nvmet_trace_ctrl_name' [-Wmissing-prototypes]
     214 | const char *nvmet_trace_ctrl_name(struct trace_seq *p, struct nvmet_ctrl *ctrl)
         |             ^~~~~~~~~~~~~~~~~~~~~


vim +/nvmet_trace_ctrl_name +214 drivers/nvme/target/trace.c

a5448fdc469d67 Minwoo Im 2019-06-12  213  
a5448fdc469d67 Minwoo Im 2019-06-12 @214  const char *nvmet_trace_ctrl_name(struct trace_seq *p, struct nvmet_ctrl *ctrl)
a5448fdc469d67 Minwoo Im 2019-06-12  215  {
a5448fdc469d67 Minwoo Im 2019-06-12  216  	const char *ret = trace_seq_buffer_ptr(p);
a5448fdc469d67 Minwoo Im 2019-06-12  217  
a5448fdc469d67 Minwoo Im 2019-06-12  218  	/*
a5448fdc469d67 Minwoo Im 2019-06-12  219  	 * XXX: We don't know the controller instance before executing the
a5448fdc469d67 Minwoo Im 2019-06-12  220  	 * connect command itself because the connect command for the admin
a5448fdc469d67 Minwoo Im 2019-06-12  221  	 * queue will not provide the cntlid which will be allocated in this
a5448fdc469d67 Minwoo Im 2019-06-12  222  	 * command.  In case of io queues, the controller instance will be
a5448fdc469d67 Minwoo Im 2019-06-12  223  	 * mapped by the extra data of the connect command.
a5448fdc469d67 Minwoo Im 2019-06-12  224  	 * If we can know the extra data of the connect command in this stage,
a5448fdc469d67 Minwoo Im 2019-06-12  225  	 * we can update this print statement later.
a5448fdc469d67 Minwoo Im 2019-06-12  226  	 */
a5448fdc469d67 Minwoo Im 2019-06-12  227  	if (ctrl)
a5448fdc469d67 Minwoo Im 2019-06-12  228  		trace_seq_printf(p, "%d", ctrl->cntlid);
a5448fdc469d67 Minwoo Im 2019-06-12  229  	else
a5448fdc469d67 Minwoo Im 2019-06-12  230  		trace_seq_printf(p, "_");
a5448fdc469d67 Minwoo Im 2019-06-12  231  	trace_seq_putc(p, 0);
a5448fdc469d67 Minwoo Im 2019-06-12  232  
a5448fdc469d67 Minwoo Im 2019-06-12  233  	return ret;
a5448fdc469d67 Minwoo Im 2019-06-12  234  }
a5448fdc469d67 Minwoo Im 2019-06-12  235  

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