Re: [updated patch 1/7] BSD Secure Levels: printk overhaul

From: aq
Date: Fri May 20 2005 - 00:22:16 EST


On 5/20/05, Michael Halcrow <mhalcrow@xxxxxxxxxx> wrote:
> On Thu, May 19, 2005 at 01:58:06PM -0700, Andrew Morton wrote:
> > Did anyone mention printk_ratelimit()?
>
> Third time's a charm. :-)
>
> I think this makes the most sense. Module size is 18284; messages are
> globally limited, but the space savings is significant.
>
> Signed-off by: Michael Halcrow <mhalcrow@xxxxxxxxxx>
>
> Index: linux-2.6.12-rc4-mm2-seclvl/security/seclvl.c
> ===================================================================
> --- linux-2.6.12-rc4-mm2-seclvl.orig/security/seclvl.c 2005-05-19 15:49:51.000000000 -0500
> +++ linux-2.6.12-rc4-mm2-seclvl/security/seclvl.c 2005-05-19 16:33:20.000000000 -0500
> @@ -102,21 +102,25 @@
> #define MY_NAME "seclvl"
>
> /**
> - * This time-limits log writes to one per second.
> + * This time-limits log writes to one per second for every message
> + * type.
> */
> -#define seclvl_printk(verb, type, fmt, arg...) \
> - do { \
> - if (verbosity >= verb) { \
> - static unsigned long _prior; \
> - unsigned long _now = jiffies; \
> - if ((_now - _prior) > HZ) { \
> - printk(type "%s: %s: " fmt, \
> - MY_NAME, __FUNCTION__ , \
> - ## arg); \
> - _prior = _now; \
> - } \
> - } \
> - } while (0)
> +static void __seclvl_printk(int verb, const char *fmt, ...)
> +{
> + va_list args;
> + va_start(args, fmt);
> + if (verbosity >= verb && printk_ratelimit()) {
> + vprintk(fmt, args);
> + }
> + va_end(args);
> +}
> +
> +/**
> + * Breaking the printk up into a macro and a function saves some text
> + * space.
> + */
> +#define seclvl_printk(verb, type, fmt, arg...) \
> + __seclvl_printk((verb), type "%s: " fmt, __FUNCTION__, ## arg);
>
> /**
> * kobject stuff
> @@ -711,7 +715,7 @@
> goto exit;
> }
> seclvl_printk(0, KERN_INFO, "seclvl: Successfully initialized.\n");
> - exit:
> + exit:
> if (rc) {
> printk(KERN_ERR "seclvl: Error during initialization: rc = "
> "[%d]\n", rc);
> -
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>

i disklike the fact that the rate limit is based on 1 sec. how about
finer-grain limit?

it is best to let user to config the litmit. 1 sec is too raw to some purpose.

regards,
aq
-
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