LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Andrew Morton <akpm@osdl.org>
To: Chuck Ebbert <cebbert@redhat.com>
Cc: linux-kernel <linux-kernel@vger.kernel.org>, Andi Kleen <ak@suse.de>
Subject: Re: [patch] i386: add option to show more code in oops reports
Date: Thu, 25 Jan 2007 14:55:04 -0800 [thread overview]
Message-ID: <20070125145504.c8c0a98a.akpm@osdl.org> (raw)
In-Reply-To: <45B7C019.1040209@redhat.com>
On Wed, 24 Jan 2007 15:22:49 -0500
Chuck Ebbert <cebbert@redhat.com> wrote:
> Sometimes we may need to see more code than the default in an oops,
> so add an option for that.
spose so, but some more justification would be nice. As would an x86_64
version?
> Signed-off-by: Chuck Ebbert <cebbert@redhat.com>
ooh, congrats.
> --- 2.6.20-rc5-32.orig/arch/i386/kernel/traps.c
> +++ 2.6.20-rc5-32/arch/i386/kernel/traps.c
> @@ -94,6 +94,7 @@ asmlinkage void spurious_interrupt_bug(v
> asmlinkage void machine_check(void);
>
> int kstack_depth_to_print = 24;
> +int code_bytes = 64;
static scope, please. And I think it should be unsigned.
> ATOMIC_NOTIFIER_HEAD(i386die_chain);
>
> int register_die_notifier(struct notifier_block *nb)
> @@ -324,7 +325,7 @@ void show_registers(struct pt_regs *regs
> */
> if (in_kernel) {
> u8 *eip;
> - int code_bytes = 64;
> + int code_prologue = code_bytes * 43 / 64;
> unsigned char c;
>
> printk("\n" KERN_EMERG "Stack: ");
> @@ -332,7 +333,7 @@ void show_registers(struct pt_regs *regs
>
> printk(KERN_EMERG "Code: ");
>
> - eip = (u8 *)regs->eip - 43;
> + eip = (u8 *)regs->eip - code_prologue;
> if (eip < (u8 *)PAGE_OFFSET ||
> probe_kernel_address(eip, c)) {
> /* try starting at EIP */
You missed this bit:
if (eip < (u8 *)PAGE_OFFSET ||
probe_kernel_address(eip, c)) {
/* try starting at EIP */
eip = (u8 *)regs->eip;
code_bytes = 32;
}
Do we really want to be modifying the global variable here?
> @@ -1191,3 +1192,15 @@ static int __init kstack_setup(char *s)
> return 1;
> }
> __setup("kstack=", kstack_setup);
> +
> +static int __init code_bytes_setup(char *s)
> +{
> + code_bytes = simple_strtoul(s, NULL, 0);
> + if (code_bytes < 64)
> + code_bytes = 64;
> + if (code_bytes > 1024)
> + code_bytes = 1024;
> +
> + return 1;
> +}
> +__setup("code_bytes=", code_bytes_setup);
I'm OK with the upper limit, but I'd sugegst that we remove the lower
limit: someone might _want_ to be able to set code_bytes=0, who knows?
And if code_bytes is unsigned, the single comparison with 1024 will suffice.
OTOH, why have any checks at all in there? If the user sets
code_bytes=0xfffffff0 and things break, he gets to own both pieces...
next prev parent reply other threads:[~2007-01-25 22:55 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-01-24 20:22 Chuck Ebbert
2007-01-25 22:55 ` Andrew Morton [this message]
2007-01-25 23:56 ` Chuck Ebbert
2007-01-29 3:44 ` Andi Kleen
2007-01-29 15:40 ` Chuck Ebbert
2007-01-29 18:03 ` Andi Kleen
2007-01-29 20:11 Chuck Ebbert
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=20070125145504.c8c0a98a.akpm@osdl.org \
--to=akpm@osdl.org \
--cc=ak@suse.de \
--cc=cebbert@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--subject='Re: [patch] i386: add option to show more code in oops reports' \
/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
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).