Re: [PATCH] seq_buf: avoid type mismatch for seq_buf_init

[Arnd Bergmann]

On Mon, Oct 26, 2020 at 6:23 PM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
> On Mon, 26 Oct 2020 17:10:58 +0100
> Arnd Bergmann <arnd@xxxxxxxxxx> wrote:
>
> > From: Arnd Bergmann <arnd@xxxxxxxx>
> >
> > Building with W=2 prints a number of warnings for one function that
> > has a pointer type mismatch:
> >
> > linux/seq_buf.h: In function 'seq_buf_init':
> > linux/seq_buf.h:35:12: warning: pointer targets in assignment from 'unsigned char *' to 'char *' differ in signedness [-Wpointer-sign]
>
> I've always hated the warning about char * and unsigned char *, as they are
> mostly meaningless. Yes, bugs happen with int to unsigned int conversions,
> but this is dealing with strings, where unsigned char * and char * are
> basically equivalent, except when it comes to one thing, which is why I
> prefer unsigned char * over char *, and that is printing out the numerical
> values of a buffer, if they go above 177, the char * prints the negative
> value, but unsigned char * keeps printing what you would expect.

I agree it's a super annoying warning, which is exactly why I sent the
fixes to shut it up in common headers. At least that way, building a specific
driver with W=2 will only show the warnings in that driver, rather than
those in header files as well.

> As this is just an annoyance (extra warnings), and not really a "fix", I'll
> queue it up for the next merge window.

Yes, that was the idea, thanks!

        Arnd