Re: [PATCH v1] ipmi: use %*ph to print small buffer

From: Andy Shevchenko
Date: Fri Oct 11 2019 - 11:12:27 EST


On Fri, Oct 11, 2019 at 07:58:14AM -0700, Joe Perches wrote:
> On Fri, 2019-10-11 at 17:52 +0300, Andy Shevchenko wrote:
> > Use %*ph format to print small buffer as hex string.
> >
> > The change is safe since the specifier can handle up to 64 bytes and taking
> > into account the buffer size of 100 bytes on stack the function has never been
> > used to dump more than 32 bytes. Note, this also avoids potential buffer
> > overflow if the length of the input buffer is bigger.
> []
> > diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
> []
> > @@ -48,14 +48,7 @@ static int handle_one_recv_msg(struct ipmi_smi *intf,
> > static void ipmi_debug_msg(const char *title, unsigned char *data,
> > unsigned int len)
> > {
> > - int i, pos;
> > - char buf[100];
> > -
> > - pos = snprintf(buf, sizeof(buf), "%s: ", title);
> > - for (i = 0; i < len; i++)
> > - pos += snprintf(buf + pos, sizeof(buf) - pos,
> > - " %2.2x", data[i]);
> > - pr_debug("%s\n", buf);
> > + pr_debug("%s: %*ph\n", title, len, buf);
> > }
> > #else
> > static void ipmi_debug_msg(const char *title, unsigned char *data,
>
> Now you might as well remove the #ifdef DEBUG above this
> and the empty function in the #else too.

It's up to maintainer.

--
With Best Regards,
Andy Shevchenko