Re: [PATCH 5/7] ath6kl: convert ath6kl_info/err/warn macros to real functions

[Kalle Valo <kvalo@qca.qualcomm.com>]

Kalle Valo <kvalo@qca.qualcomm.com> writes:

>> Note that by inserting the tracing here later, you're relying on the
>> fact that "%pV" does va_copy(). This isn't true in all kernel versions,
>> I think there's on version or so where %pV is supported but didn't
>> va_copy(). That may lead to problems (I don't remember what kind) here.
>>
>> This is relevant for compat only, I think I carry a patch there to add
>> va_copy() into the tracing or something.
>
> Compat-drivers has 55-iwlwifi-msg-trace-fix.patch which says:
>
> "In recent kernels, %pV will copy the va_list before using it.
> This isn't true for all kernels, so copy the va_list for use
> by the dev_*() functions, otherwise the kernel will crash if
> the message is printed and traced."
>
> I take it that the problem happens when the message is both printed and
> traced at the same time. So ath6kl will need a similar patch as well.

For the archives: I'm guessing this is the commit which fixed the issue:

commit 5756b76e4db643d8f75174a9a50038523d4b9e32
Author: Jan Beulich <JBeulich@suse.com>
Date:   Mon Mar 5 16:49:24 2012 +0000

    vsprintf: make %pV handling compatible with kasprintf()

And git-describe tells me that it was introduced in 3.3-rc7, so quite
recent.

Kalle