Hi Steve-
> On May 12, 2021, at 12:26 PM, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
> On Wed, 12 May 2021 11:35:02 -0400
> Chuck Lever <chuck.lever@xxxxxxxxxx> wrote:
>
>> Since commit 9a6944fee68e ("tracing: Add a verifier to check string
>> pointers for trace events"), which was merged in v5.13-rc1,
>> TP_printk() no longer tacitly supports the "%.*s" format specifier.
>
> Hmm, this looks like a bug. I should allow the %.*s notation.
>
> I probably should fix that.
The underlying need is to support non-NUL-terminated C strings.
I assumed that since the commentary around 9a6944fee68e claims
the proper way to trace C strings is to use __string and friends,
and those do not support non-NUL-terminated strings, that such
strings are really not first-class citizens. Thus I concluded
that my use of '%.*s' was incorrect.
Having some __string-style helpers that can deal with such
strings would be valuable.
--
Chuck Lever
