Re: [PATCH v4 07/11] lib/vsprintf: Remove support for %pF and %pf in favour of %pS and %ps

From: Andy Shevchenko
Date: Mon Sep 02 2019 - 12:01:50 EST

On Mon, Sep 02, 2019 at 04:39:35PM +0200, Petr Mladek wrote:
> On Mon 2019-09-02 11:32:36, Sakari Ailus wrote:
> > %pS and %ps are now the preferred conversion specifiers to print function
> > names. The functionality is equivalent; remove the old, deprecated %pF
> > and %pf support.
> Hmm, I see the following in master:
> $> git grep %pF
> tools/lib/traceevent/Documentation/libtraceevent-func_apis.txt:or events have "%pF" or "%pS" parameter in its format string. It is common to
> $> git grep %pf
> tools/lib/traceevent/event-parse.c: if (asprintf(&format, "%%pf: (NO FORMAT FOUND at %llx)\n", addr) < 0)
> tools/lib/traceevent/event-parse.c: if (asprintf(&format, "%s: %s", "%pf", printk->printk) < 0)
> I wonder how this is related to printk(). In each case, it seems

It's going thru binary printf() I suppose. The fist stage just saves the format
string and argument addresses or so and prints in later on when user is looking
for human-readable output.

> that libtraceevent somehow implements the non-standard kernel
> %p mofifiers. It looks error-prone to keep another %pf user
> with the old semantic around.
> I am adding some tracing people into CC.

With Best Regards,
Andy Shevchenko