lkml.org 
[lkml]   [2005]   [Jun]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] Kprobes: Verify probepoint in register_jprobe()
Luca Falavigna <dktrkranz@gmail.com> wrote:
>
> This patch, built against version 2.6.12, checks if probepoint address is a
> function entry point using an offset value, obtained from kallsyms_lookup().
> If offset is zero, we register jprobe, otherwise we return -EINVAL.
>

a) kallsyms holds symbols other than just function names.

b) This won't work with CONFIG_KALLSYMS=n

>
> --- ./kernel/kprobes.c.orig 2005-06-29 00:17:43.000000000 +0000
> +++ ./kernel/kprobes.c 2005-06-29 11:08:02.000000000 +0000
> @@ -33,6 +33,7 @@
> #include <linux/hash.h>
> #include <linux/init.h>
> #include <linux/module.h>
> +#include <linux/kallsyms.h>
> #include <asm/cacheflush.h>
> #include <asm/errno.h>
> #include <asm/kdebug.h>
> @@ -245,7 +246,15 @@ static struct notifier_block kprobe_exce
>
> int register_jprobe(struct jprobe *jp)
> {
> - /* Todo: Verify probepoint is a function entry point */
> + unsigned long size, offset;
> + char *modname, namebuf[KSYM_NAME_LEN+1];
> +
> + kallsyms_lookup((unsigned long)jp->kp.addr, &size,
> + &offset, &modname, namebuf);
> +
> + if(unlikely(offset))
> + return -EINVAL;
> +
> jp->kp.pre_handler = setjmp_pre_handler;
> jp->kp.break_handler = longjmp_break_handler;
>

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

\
 
 \ /
  Last update: 2005-06-29 20:36    [W:0.063 / U:0.568 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site