Re: [PATCH v1] printk: add dummy vprintk_emit for when CONFIG_PRINTK=n

[Sergey Senozhatsky]

On (08/27/19 21:45), Brendan Higgins wrote:
[..]
> I actually use it in a very similar way as dev_printk() does. I am using
> it to define an equivalent kunit_printk(), which takes a log level, and
> adds its own test information to the log.
> 
> What I have now is:
> 
> static int kunit_vprintk_emit(int level, const char *fmt, va_list args)
> {
> 	return vprintk_emit(0, level, NULL, 0, fmt, args);
> }
> 
> static int kunit_printk_emit(int level, const char *fmt, ...)
> {
> 	va_list args;
> 	int ret;
> 
> 	va_start(args, fmt);
> 	ret = kunit_vprintk_emit(level, fmt, args);
> 	va_end(args);
> 
> 	return ret;
> }
> 
> static void kunit_vprintk(const struct kunit *test,
> 			  const char *level,
> 			  struct va_format *vaf)
> {
> 	kunit_printk_emit(level[1] - '0', "\t# %s: %pV", test->name, vaf);
> }

Basically, for prefixes we have pr_fmt().

#define pr_fmt(fmt) "module name: " fmt

but pr_fmt() is mostly for static prefixes. If that doesn't work for
you, then maybe you can tweak kunit_foo() macros?

E.g. something like this

#define kunit_info(test, fmt, ...)                                   \
	printk(KERN_INFO "\t# %s: " pr_fmt(fmt), (test)->name, ##__VA_ARGS__)

#define kunit_err(test, fmt, ...)                                    \
	printk(KERN_ERR "\t# %s: " pr_fmt(fmt), (test)->name, ##__VA_ARGS__)

#define kunit_debug(test, fmt, ...)                                  \
	printk(KERN_DEBUG "\t# %s: " pr_fmt(fmt), (test)->name, ##__VA_ARGS__)

Would that do the trick? Am I missing something?

	-ss