kernel/bpf/diagnostics.c:179:40: warning: diagnostic behavior may be improved by adding the 'format(printf, 2, 3)' attribute to the declaration of 'diag_write'

kernel/bpf/diagnostics.c:179:40: warning: diagnostic behavior may be improved by adding the 'format(printf, 2, 3)' attribute to the declaration of 'diag_write'

[kernel test robot]

tree:   https://github.com/intel-lab-lkp/linux/commits/Kumar-Kartikeya-Dwivedi/bpf-Add-verifier-diagnostics-report-helpers/20260713-235352
head:   481b092f62f3f331a53a188543b27495e7a1763c
commit: 1d00722166456d81ed4d556f7d213f162146d1ce bpf: Add verifier diagnostic event log
date:   15 hours ago
config: x86_64-kexec (https://download.01.org/0day-ci/archive/20260714/202607140852.i9ntTAJ9-lkp@intel.com/config)
compiler: clang version 22.1.8 (https://github.com/llvm/llvm-project ca7933e47d3a3451d81e72ac174dcb5aa28b59d1)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260714/202607140852.i9ntTAJ9-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/202607140852.i9ntTAJ9-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> kernel/bpf/diagnostics.c:179:40: warning: diagnostic behavior may be improved by adding the 'format(printf, 2, 3)' attribute to the declaration of 'diag_write' [-Wmissing-format-attribute]
     171 | static void diag_write(struct bpf_verifier_env *env, const char *fmt, ...)
         | __attribute__((format(printf, 2, 3))) 
     172 | {
     173 |         va_list args;
     174 | 
     175 |         if (!bpf_diag_enabled(env))
     176 |                 return;
     177 | 
     178 |         va_start(args, fmt);
     179 |         bpf_verifier_vlog(&env->log, fmt, args);
         |                                               ^
   kernel/bpf/diagnostics.c:171:13: note: 'diag_write' declared here
     171 | static void diag_write(struct bpf_verifier_env *env, const char *fmt, ...)
         |             ^
   kernel/bpf/diagnostics.c:321:48: warning: diagnostic behavior may be improved by adding the 'format(printf, 2, 0)' attribute to the declaration of 'diag_vprint_indented' [-Wmissing-format-attribute]
     314 | static void diag_vprint_indented(struct bpf_verifier_env *env, const char *fmt, va_list args)
         | __attribute__((format(printf, 2, 0))) 
     315 | {
     316 |         char *buf;
     317 | 
     318 |         if (!bpf_diag_enabled(env))
     319 |                 return;
     320 | 
     321 |         buf = kvasprintf(GFP_KERNEL_ACCOUNT, fmt, args);
         |                                                       ^
   kernel/bpf/diagnostics.c:314:13: note: 'diag_vprint_indented' declared here
     314 | static void diag_vprint_indented(struct bpf_verifier_env *env, const char *fmt, va_list args)
         |             ^
   kernel/bpf/diagnostics.c:432:77: warning: diagnostic behavior may be improved by adding the 'format(printf, 2, 3)' attribute to the declaration of 'diag_insn_print' [-Wmissing-format-attribute]
     422 | static void diag_insn_print(void *private_data, const char *fmt, ...)
         | __attribute__((format(printf, 2, 3))) 
     423 | {
     424 |         struct bpf_diag_insn_ctx *ctx = private_data;
     425 |         struct bpf_diag_insn_buf *buf = &ctx->buf;
     426 |         va_list args;
     427 | 
     428 |         if (buf->len >= buf->size)
     429 |                 return;
     430 | 
     431 |         va_start(args, fmt);
     432 |         buf->len += vscnprintf(buf->buf + buf->len, buf->size - buf->len, fmt, args);
         |                                                                                    ^
   kernel/bpf/diagnostics.c:422:13: note: 'diag_insn_print' declared here
     422 | static void diag_insn_print(void *private_data, const char *fmt, ...)
         |             ^
   kernel/bpf/diagnostics.c:738:13: warning: unused function 'diag_print_history' [-Wunused-function]
     738 | static void diag_print_history(struct bpf_verifier_env *env)
         |             ^~~~~~~~~~~~~~~~~~
   kernel/bpf/diagnostics.c:594:13: warning: unused function 'diag_report_reason' [-Wunused-function]
     594 | static void diag_report_reason(struct bpf_verifier_env *env, const char *fmt, ...)
         |             ^~~~~~~~~~~~~~~~~~
   kernel/bpf/diagnostics.c:608:13: warning: unused function 'diag_report_suggestion' [-Wunused-function]
     608 | static void diag_report_suggestion(struct bpf_verifier_env *env, const char *fmt, ...)
         |             ^~~~~~~~~~~~~~~~~~~~~~
   6 warnings generated.


vim +179 kernel/bpf/diagnostics.c

   170	
   171	static void diag_write(struct bpf_verifier_env *env, const char *fmt, ...)
   172	{
   173		va_list args;
   174	
   175		if (!bpf_diag_enabled(env))
   176			return;
   177	
   178		va_start(args, fmt);
 > 179		bpf_verifier_vlog(&env->log, fmt, args);
   180		va_end(args);
   181	}
   182	

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki