Re: [RFC[ Alloc in vsprintf

From: Joe Perches
Date: Sun Jun 26 2022 - 16:13:34 EST


On Sun, 2022-06-26 at 16:06 -0400, Kent Overstreet wrote:
> On Sun, Jun 26, 2022 at 12:53:26PM -0700, Joe Perches wrote:
> > In a reply to the printbufs thread, I wrote a proposal to use an
> > alloc to reduce stack in vsprintf when CONFIG_KALLSYMS is enabled.
> >
> > No one has replied to this but I think it's somewhat sensible.
> >
> > Thoughts?
>
> As functions get converted to printbufs the separate stack allocated buffers
> become unnecessary, because printbufs have helpers that do bounds checking and
> make outputting to the vsprintf buffer painless. So it's not necessary - I
> haven't fully converted symbol_string() yet but I'll do so by the time I mail
> out the next round of patches.

_If_ the printfbufs patch series gets applied.
I think that series is not great yet.

Even if applied via something like the printbufs series, the
stack use of this function needs/could use attending.

~700 bytes of stack use here isn't great.