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

From: Joe Perches
Date: Fri Oct 11 2019 - 10:58:19 EST


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.