From: Luca Barbieri <ldb@ldb.ods.org>
To: Linux-Kernel ML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] (re-xmit): kprobes for i386
Date: 20 Aug 2002 16:06:58 +0200 [thread overview]
Message-ID: <1029852418.8662.267.camel@ldb> (raw)
In-Reply-To: <3D62365E.8030905@iram.es>
[-- Attachment #1: Type: text/plain, Size: 613 bytes --]
> > Something like this:
> > ENTRY(debug)
> > testl $0x3, 4(%esp)
> > jz handle_kernel_mode_debug
> >
>
> This check is insufficient, it can go the wrong way if the interrupted
> taks is in vm 86 mode (and open a big security hole, I believe).
Right.
This test from ret_from_intr could be used instead:
push %es
push %ds
push %eax
movl 8(%esp), %eax
movb 4(%esp), %al
testl $(VM_MASK | 3), %eax
jz handle_kernel_mode
There is however a potential register stall for the eax read after the
al write.
BTW, vm86 has the VM flag set so the comment in ret_from_intr is wrong.
The code seems to be right though.
[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 189 bytes --]
next prev parent reply other threads:[~2002-08-20 14:02 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-08-20 4:39 [PATCH] (re-xmit): kprobes for i386 Rusty Russell
2002-08-20 8:19 ` Christoph Hellwig
2002-08-20 10:25 ` Rusty Russell
2002-08-20 11:54 ` Luca Barbieri
[not found] ` <3D62365E.8030905@iram.es>
2002-08-20 14:06 ` Luca Barbieri [this message]
2002-08-20 19:29 ` Linus Torvalds
2002-08-21 1:03 ` Rusty Russell
2002-08-21 1:29 ` Luca Barbieri
2002-08-21 4:21 ` Rusty Russell
2002-08-21 8:31 ` Vamsi Krishna S .
2002-08-21 10:48 ` Rusty Russell
2002-08-21 12:33 ` Vamsi Krishna S .
-- strict thread matches above, loose matches on Subject: below --
2002-09-20 6:16 [PATCH] Re-xmit: " Rusty Russell
2002-08-12 8:18 [PATCH] (Re-xmit) " Rusty Russell
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=1029852418.8662.267.camel@ldb \
--to=ldb@ldb.ods.org \
--cc=linux-kernel@vger.kernel.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.