linux-kernel - Re: [PATCH] i2c: Add message transfer tracepoints for I2C and SMBUS

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 13 Dec 2013 12:39:02 -0500
From:	Steven Rostedt <rostedt@...dmis.org>
To:	David Howells <dhowells@...hat.com>
Cc:	Jean Delvare <khali@...ux-fr.org>, linux-i2c@...r.kernel.org,
	linux-kernel@...r.kernel.org, Wolfram Sang <wolfram@...-dreams.de>
Subject: Re: [PATCH] i2c: Add message transfer tracepoints for I2C and SMBUS

On Fri, 13 Dec 2013 17:04:14 +0000
David Howells <dhowells@...hat.com> wrote:

> Steven Rostedt <rostedt@...dmis.org> wrote:
> 
> > > Would it be possible to print this as a string rather than a number?
> > > The protocol numbers are completely arbitrary, so the reader would have
> > > to open i2c.h each time to figure out what is what.
> > 
> > That can be done in the TP_printk() with:
> > 
> > 	".. %s ..", ..,
> > 	__print_symbolic(__entry->protocol,
> > 		{ I2C_SMBUS_QUICK	,	"QUICK"	},
> > 		{ I2C_SMBUS_BYTE	,	"BYTE"	},
> > 		{ I2C_SMBUS_BYTE_DATA	,	"BYTE_DATA" },
> > 		[...]
> > 		{ I2C_SMBUS_I2C_BLOCK_DATA,	"I2C_BLOCK_DATA"}), ...
> 
> What happens if the number isn't in the table?

It simply prints the hex value. See trace_output.c:

const char *
ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
			 const struct trace_print_flags *symbol_array)
{
	int i;
	const char *ret = p->buffer + p->len;

	for (i = 0;  symbol_array[i].name; i++) {

		if (val != symbol_array[i].mask)
			continue;

		trace_seq_puts(p, symbol_array[i].name);
		break;
	}

	if (ret == (const char *)(p->buffer + p->len))
		trace_seq_printf(p, "0x%lx", val);
		
	trace_seq_putc(p, 0);

	return ret;
}

-- Steve

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/