From: Andrew Morton <akpm@osdl.org>
To: Chuck Ebbert <76306.1226@compuserve.com>
Cc: linux-kernel@vger.kernel.org, torvalds@osdl.org, efault@gmx.de
Subject: Re: [patch] i386: handle_BUG(): don't print garbage if debug info unavailable
Date: Tue, 11 Jul 2006 01:27:55 -0700 [thread overview]
Message-ID: <20060711012755.59965932.akpm@osdl.org> (raw)
In-Reply-To: <200607101034_MC3-1-C497-51F7@compuserve.com>
On Mon, 10 Jul 2006 10:30:55 -0400
Chuck Ebbert <76306.1226@compuserve.com> wrote:
> handle_BUG() tries to print file and line number even when
> they're not available (CONFIG_DEBUG_BUGVERBOSE is not set.)
> Change this to print a message stating info is unavailable
> instead of printing a misleading message.
>
> Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
>
> ---
>
> Compile tested only, with/without CONFIG_DEBUG_BUGVERBOSE.
>
> arch/i386/kernel/traps.c | 20 +++++++++++++-------
> 1 files changed, 13 insertions(+), 7 deletions(-)
>
> --- 2.6.18-rc1-nb.orig/arch/i386/kernel/traps.c
> +++ 2.6.18-rc1-nb/arch/i386/kernel/traps.c
> @@ -324,13 +324,14 @@ void show_registers(struct pt_regs *regs
>
> static void handle_BUG(struct pt_regs *regs)
> {
> + unsigned long eip = regs->eip;
> unsigned short ud2;
> +
> +#ifdef CONFIG_DEBUG_BUGVERBOSE
> unsigned short line;
> char *file;
> char c;
> - unsigned long eip;
> -
> - eip = regs->eip;
> +#endif
>
> if (eip < PAGE_OFFSET)
> goto no_bug;
> @@ -338,21 +339,26 @@ static void handle_BUG(struct pt_regs *r
> goto no_bug;
> if (ud2 != 0x0b0f)
> goto no_bug;
> + printk(KERN_EMERG "------------[ cut here ]------------\n");
> +
> +#ifdef CONFIG_DEBUG_BUGVERBOSE
> if (__get_user(line, (unsigned short __user *)(eip + 2)))
> - goto bug;
> + goto no_info;
> if (__get_user(file, (char * __user *)(eip + 4)) ||
> (unsigned long)file < PAGE_OFFSET || __get_user(c, file))
> file = "<bad filename>";
>
> - printk(KERN_EMERG "------------[ cut here ]------------\n");
> printk(KERN_EMERG "kernel BUG at %s:%d!\n", file, line);
> +#else
> + goto no_info;
> +#endif
>
> no_bug:
> return;
>
> /* Here we know it was a BUG but file-n-line is unavailable */
> -bug:
> - printk(KERN_EMERG "Kernel BUG\n");
> +no_info:
> + printk(KERN_EMERG "Kernel BUG at [verbose debug info unavailable]\n");
> }
>
I think we can do it a lot more tidily.
static void handle_BUG(struct pt_regs *regs)
{
unsigned long eip = regs->eip;
unsigned short ud2;
if (eip < PAGE_OFFSET)
return;
if (__get_user(ud2, (unsigned short __user *)eip))
return;
if (ud2 != 0x0b0f)
return;
printk(KERN_EMERG "------------[ cut here ]------------\n");
#ifdef CONFIG_DEBUG_BUGVERBOSE
do {
unsigned short line;
char *file;
char c;
if (__get_user(line, (unsigned short __user *)(eip + 2)))
break;
if (__get_user(file, (char * __user *)(eip + 4)) ||
(unsigned long)file < PAGE_OFFSET || __get_user(c, file))
file = "<bad filename>";
printk(KERN_EMERG "kernel BUG at %s:%d!\n", file, line);
return;
} while (0);
#endif
printk(KERN_EMERG "Kernel BUG at [verbose debug info unavailable]\n");
}
OK?
next prev parent reply other threads:[~2006-07-11 8:28 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-07-10 14:30 Chuck Ebbert
2006-07-11 8:27 ` Andrew Morton [this message]
2006-07-11 10:52 ` Nick Piggin
2006-07-11 17:02 ` Linus Torvalds
2006-07-11 17:58 ` Ray Lee
2006-07-11 23:42 ` Andrew Morton
2006-07-11 23:55 ` Linus Torvalds
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