Put the code for appending the optional "buildid" into a helper function, It makes __sprint_symbol() better readable.
Also print a warning when the "modname" is set and the "buildid" isn't. It might catch a situation when some lookup function in kallsyms_lookup_buildid() does not handle the "buildid". Use pr_*_once() to avoid an infinite recursion when the function is called from printk(). The recursion is rather theoretical but better be on the safe side. Signed-off-by: Petr Mladek <[email protected]> --- kernel/kallsyms.c | 42 +++++++++++++++++++++++++++++++++--------- 1 file changed, 33 insertions(+), 9 deletions(-) diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index ffb64eaa0505..f25b122397ce 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -432,6 +432,37 @@ int lookup_symbol_name(unsigned long addr, char *symname) return lookup_module_symbol_name(addr, symname); } +#ifdef CONFIG_STACKTRACE_BUILD_ID + +static int append_buildid(char *buffer, const char *modname, + const unsigned char *buildid) +{ + if (!modname) + return 0; + + if (!buildid) { + pr_warn_once("Undefined buildid for the module %s\n", modname); + return 0; + } + + /* build ID should match length of sprintf */ +#ifdef CONFIG_MODULES + static_assert(sizeof(typeof_member(struct module, build_id)) == 20); +#endif + + return sprintf(buffer, " %20phN", buildid); +} + +#else /* CONFIG_STACKTRACE_BUILD_ID */ + +static int append_buildid(char *buffer, const char *modname, + const unsigned char *buildid) +{ + return 0; +} + +#endif /* CONFIG_STACKTRACE_BUILD_ID */ + /* Look up a kernel symbol and return it in a text buffer. */ static int __sprint_symbol(char *buffer, unsigned long address, int symbol_offset, int add_offset, int add_buildid) @@ -454,15 +485,8 @@ static int __sprint_symbol(char *buffer, unsigned long address, if (modname) { len += sprintf(buffer + len, " [%s", modname); -#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) - if (add_buildid && buildid) { - /* build ID should match length of sprintf */ -#if IS_ENABLED(CONFIG_MODULES) - static_assert(sizeof(typeof_member(struct module, build_id)) == 20); -#endif - len += sprintf(buffer + len, " %20phN", buildid); - } -#endif + if (add_buildid) + len += append_buildid(buffer + len, modname, buildid); len += sprintf(buffer + len, "]"); } -- 2.52.0
