[PROBLEM linux-next]

[Mirsad Todorovac]

Hi, all,

This is the result of testing randconfig with KCONFIG_SEED=0xEE7AB52F in next-20240703 vanilla tree on
Ubuntu 22.04 LTS. GCC used is GCC (Ubuntu 12.3.0-1ubuntu1~22.04) 12.3.0.

The particular error is as follows:

In file included from ./include/asm-generic/bug.h:22,
                 from ./arch/x86/include/asm/bug.h:87,
                 from ./include/linux/bug.h:5,
                 from ./include/linux/fortify-string.h:6,
                 from ./include/linux/string.h:374,
                 from ./arch/x86/include/asm/page_32.h:18,
                 from ./arch/x86/include/asm/page.h:14,
                 from ./arch/x86/include/asm/processor.h:20,
                 from ./arch/x86/include/asm/timex.h:5,
                 from ./include/linux/timex.h:67,
                 from ./include/linux/time32.h:13,
                 from ./include/linux/time.h:60,
                 from ./include/linux/stat.h:19,
                 from ./include/linux/module.h:13,
                 from drivers/mtd/mtdpart.c:10:
drivers/mtd/mtdpart.c: In function ‘parse_mtd_partitions’:
drivers/mtd/mtdpart.c:693:34: error: ‘%s’ directive argument is null [-Werror=format-overflow=]
  693 |                         pr_debug("%s: got parser %s\n", master->name,
      |                                  ^~~~~~~~~~~~~~~~~~~~~
./include/linux/printk.h:376:21: note: in definition of macro ‘pr_fmt’
  376 | #define pr_fmt(fmt) fmt
      |                     ^~~
./include/linux/dynamic_debug.h:248:9: note: in expansion of macro ‘__dynamic_func_call_cls’
  248 |         __dynamic_func_call_cls(__UNIQUE_ID(ddebug), cls, fmt, func, ##__VA_ARGS__)
      |         ^~~~~~~~~~~~~~~~~~~~~~~
./include/linux/dynamic_debug.h:250:9: note: in expansion of macro ‘_dynamic_func_call_cls’
  250 |         _dynamic_func_call_cls(_DPRINTK_CLASS_DFLT, fmt, func, ##__VA_ARGS__)
      |         ^~~~~~~~~~~~~~~~~~~~~~
./include/linux/dynamic_debug.h:269:9: note: in expansion of macro ‘_dynamic_func_call’
  269 |         _dynamic_func_call(fmt, __dynamic_pr_debug,             \
      |         ^~~~~~~~~~~~~~~~~~
./include/linux/printk.h:610:9: note: in expansion of macro ‘dynamic_pr_debug’
  610 |         dynamic_pr_debug(fmt, ##__VA_ARGS__)
      |         ^~~~~~~~~~~~~~~~
drivers/mtd/mtdpart.c:693:25: note: in expansion of macro ‘pr_debug’
  693 |                         pr_debug("%s: got parser %s\n", master->name,
      |                         ^~~~~~~~
drivers/mtd/mtdpart.c:693:50: note: format string is defined here
  693 |                         pr_debug("%s: got parser %s\n", master->name,
      |                                                  ^~

Offending commit is 5b644aa012f67.

Offending code is here:

  668 int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
  669                          struct mtd_part_parser_data *data)
  670 {
  671         struct mtd_partitions pparts = { };
  672         struct mtd_part_parser *parser;
  673         int ret, err = 0;
  674 
  675         if (!types)
  676                 types = mtd_is_partition(master) ? default_subpartition_types :
  677                         default_mtd_part_types;
  678 
  679         for ( ; *types; types++) {
  680                 /*
  681                  * ofpart is a special type that means OF partitioning info
  682                  * should be used. It requires a bit different logic so it is
  683                  * handled in a separated function.
  684                  */
  685                 if (!strcmp(*types, "ofpart")) {
  686                         ret = mtd_part_of_parse(master, &pparts);
  687                 } else {
  688                         pr_debug("%s: parsing partitions %s\n", master->name,
  689                                  *types);
  690                         parser = mtd_part_parser_get(*types);
  691                         if (!parser && !request_module("%s", *types))
  692                                 parser = mtd_part_parser_get(*types);
→ 693                         pr_debug("%s: got parser %s\n", master->name,
→ 694                                 parser ? parser->name : NULL);
  695                         if (!parser)
  696                                 continue;
  697                         ret = mtd_part_do_parse(parser, master, &pparts, data);
  698                         if (ret <= 0)
  699                                 mtd_part_parser_put(parser);
  700                 }
  701                 /* Found partitions! */
  702                 if (ret > 0) {
  703                         err = add_mtd_partitions(master, pparts.parts,
  704                                                  pparts.nr_parts);
  705                         mtd_part_parser_cleanup(&pparts);
  706                         return err ? err : pparts.nr_parts;
  707                 }
  708                 /*
  709                  * Stash the first error we see; only report it if no parser
  710                  * succeeds
  711                  */
  712                 if (ret < 0 && !err)
  713                         err = ret;
  714         }
  715         return err;
  716 }

Proposed non-intrusive fix resolves the warning/error, but I could not test the code.
(I don't have the physical device.)

-----------------><------------------------------------------
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 6811a714349d..81665d67ed2d 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -691,7 +691,7 @@ int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
                        if (!parser && !request_module("%s", *types))
                                parser = mtd_part_parser_get(*types);
                        pr_debug("%s: got parser %s\n", master->name,
-                               parser ? parser->name : NULL);
+                               parser ? parser->name : "(null"));
                        if (!parser)
                                continue;
                        ret = mtd_part_do_parse(parser, master, &pparts, data);


Hope this helps.

Best regards,
Mirsad Todorovac