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

On Tue, Aug 27, 2019 at 10:24 PM Sergey Senozhatsky sergey.senozhatsky.work@gmail.com wrote:

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?

That doesn't work. The prefix is dynamic.

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?

This appears to work. I will send out a patch that incorporates this.

Thanks!