Re: [PATCH v5] tracing/eprobes: Allow use of BTF names to dereference pointers

[kernel test robot]

Hi Steven,

kernel test robot noticed the following build errors:

[auto build test ERROR on trace/for-next]
[also build test ERROR on linus/master v7.1-rc4 next-20260519]
[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/Steven-Rostedt/tracing-eprobes-Allow-use-of-BTF-names-to-dereference-pointers/20260520-011353
base:   https://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace for-next
patch link:    https://lore.kernel.org/r/20260519130144.40e71a00%40fedora
patch subject: [PATCH v5] tracing/eprobes: Allow use of BTF names to dereference pointers
config: arc-defconfig (https://download.01.org/0day-ci/archive/20260520/202605200549.zZkT9xWc-lkp@xxxxxxxxx/config)
compiler: arc-linux-gcc (GCC) 15.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260520/202605200549.zZkT9xWc-lkp@xxxxxxxxx/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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202605200549.zZkT9xWc-lkp@xxxxxxxxx/

All errors (new ones prefixed by >>):

   kernel/trace/trace_probe.c: In function 'parse_probe_vars':
   kernel/trace/trace_probe.c:1035:21: error: implicit declaration of function 'parse_trace_event'; did you mean 'parse_trace_event_arg'? [-Wimplicit-function-declaration]
    1035 |                 if (parse_trace_event(arg, code, ctx) < 0)
         |                     ^~~~~~~~~~~~~~~~~
         |                     parse_trace_event_arg
   kernel/trace/trace_probe.c: In function 'sprint_nth_btf_arg':
   kernel/trace/trace_probe.c:1803:27: error: implicit declaration of function 'ctx_btf' [-Wimplicit-function-declaration]
    1803 |         struct btf *btf = ctx_btf(ctx);
         |                           ^~~~~~~
>> kernel/trace/trace_probe.c:1803:27: error: initialization of 'struct btf *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
   kernel/trace/trace_probe.c: At top level:
   kernel/trace/trace_probe.c:318:12: warning: 'parse_trace_event_arg' defined but not used [-Wunused-function]
     318 | static int parse_trace_event_arg(char *arg, struct fetch_insn *code,
         |            ^~~~~~~~~~~~~~~~~~~~~


vim +1803 kernel/trace/trace_probe.c

  1797	
  1798	static int sprint_nth_btf_arg(int idx, const char *type,
  1799				      char *buf, int bufsize,
  1800				      struct traceprobe_parse_context *ctx)
  1801	{
  1802		const char *name;
> 1803		struct btf *btf = ctx_btf(ctx);
  1804		int ret;
  1805	
  1806		if (idx >= ctx->nr_params) {
  1807			trace_probe_log_err(0, NO_BTFARG);
  1808			return -ENOENT;
  1809		}
  1810		name = btf_name_by_offset(btf, ctx->params[idx].name_off);
  1811		if (!name) {
  1812			trace_probe_log_err(0, NO_BTF_ENTRY);
  1813			return -ENOENT;
  1814		}
  1815		ret = snprintf(buf, bufsize, "%s%s", name, type);
  1816		if (ret >= bufsize) {
  1817			trace_probe_log_err(0, ARGS_2LONG);
  1818			return -E2BIG;
  1819		}
  1820		return ret;
  1821	}
  1822	

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