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 [patch] i386: handle_BUG(): don't print garbage if debug info unavailable 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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20060711012755.59965932.akpm@osdl.org \
--to=akpm@osdl.org \
--cc=76306.1226@compuserve.com \
--cc=efault@gmx.de \
--cc=linux-kernel@vger.kernel.org \
--cc=torvalds@osdl.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.