On Tue, Aug 27, 2019 at 3:38 PM Tim.Bird@sony.com wrote:
-----Original Message----- From: Brendan Higgins
On Tue, Aug 27, 2019 at 3:00 PM shuah shuah@kernel.org wrote:
On 8/27/19 3:36 PM, Brendan Higgins wrote:
On Tue, Aug 27, 2019 at 2:09 PM Brendan Higgins brendanhiggins@google.com wrote:
On Tue, Aug 27, 2019 at 2:03 PM Brendan Higgins brendanhiggins@google.com wrote:
On Tue, Aug 27, 2019 at 1:21 PM shuah shuah@kernel.org wrote: > > On 8/27/19 11:49 AM, Brendan Higgins wrote: >> Previously KUnit assumed that printk would always be present,
which is
>> not a valid assumption to make. Fix that by ifdefing out functions
which
>> directly depend on printk core functions similar to what dev_printk >> does. >> >> Reported-by: Randy Dunlap rdunlap@infradead.org >> Link: https://lore.kernel.org/linux-kselftest/0352fae9-564f-4a97-
715a-fabe016259df@kernel.org/T/#t
>> Cc: Stephen Rothwell sfr@canb.auug.org.au >> Signed-off-by: Brendan Higgins brendanhiggins@google.com >> --- >> include/kunit/test.h | 7 +++++++ >> kunit/test.c | 41 ++++++++++++++++++++++++----------------- >> 2 files changed, 31 insertions(+), 17 deletions(-) >> >> diff --git a/include/kunit/test.h b/include/kunit/test.h >> index 8b7eb03d4971..339af5f95c4a 100644 >> --- a/include/kunit/test.h >> +++ b/include/kunit/test.h >> @@ -339,9 +339,16 @@ static inline void *kunit_kzalloc(struct kunit
*test, size_t size, gfp_t gfp)
[...] > Okay after reviewing this, I am not sure why you need to do all > this. > > Why can't you just change the root function that throws the warn: > > static int kunit_vprintk_emit(int level, const char *fmt, va_list args) > { > return vprintk_emit(0, level, NULL, 0, fmt, args); > } > > You aren'r really doing anything extra here, other than calling > vprintk_emit()
Yeah, I did that a while ago. I think it was a combination of trying to avoid an extra layer of adding and then removing the log level, and that's what dev_printk and friends did.
But I think you are probably right. It's a lot of maintenance overhead to get rid of that. Probably best to just use what the printk people have.
> Unless I am missing something, can't you solve this problem by
including
> printk.h and let it handle the !CONFIG_PRINTK case?
Randy, I hope you don't mind, but I am going to ask you to re-ack my next revision since it basically addresses the problem in a totally different way.
Actually, scratch that. Checkpatch doesn't like me calling printk without using a KERN_<LEVEL>.
Now that I am thinking back to when I wrote this. I think it also might not like using a dynamic KERN_<LEVEL> either (printk("%s my message", KERN_INFO)).
I am going to have to do some more investigation.
Alright, I am pretty sure it is safe to do printk("%smessage",
KERN_<LEVEL>);
Looking at the printk implementation, it appears to do the format before it checks the log level:
https://elixir.bootlin.com/linux/v5.2.10/source/kernel/printk/printk.c#L1907
So I am pretty sure we can do it either with the vprintk_emit or with
printk.
Let me see if we are on the same page first. I am asking if you can just include printk.h for vprintk_emit() define for both CONFIG_PRINTK and !CONFIG_PRINTK cases.
Ah sorry, I misunderstood you.
No, that doesn't work. I tried including linux/printk.h, and I get the same error.
The reason for this is that vprintk_emit() is only defined when CONFIG_PRINTK=y:
Ugh. That's just a bug in include/linux/printk.h
There should be a stub definition for vprintk_emit() in the #else part of #ifdef CONFIG_PRINTK.
You shouldn't be dealing with whether printk is present or not in the kunit code. All the printk-related routines are supposed to evaporate themselves, based on the conditional in include/linux/printk.h
That should be fixed there instead of in your code.
Alright. That makes sense.
I will submit a patch to fix it.
Sorry for not suggesting that, I just assumed that it was my mistake in how I was using printk.
Let me know if you'd like me to submit a patch for that. I only hesitate because your patch depends on it, and IMHO it makes more sense to include it in your batch than separately. Otherwise there's a patch race condition.
Thanks for clearing up the confusion!