From: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
To: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org,
Timo Juhani Lindfors <timo.lindfors@iki.fi>,
Pavel Emelyanov <xemul@parallels.com>,
Jiri Kosina <jkosina@suse.cz>,
Nadia Yvette Chambers <nyc@holomorphy.com>,
yrl.pp-manager.tt@hitachi.com,
"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH -tip ] [BUGFIX] kprobes: Move hash_64() into .text.kprobe section
Date: Tue, 12 Mar 2013 10:05:27 +0530 [thread overview]
Message-ID: <20130312043526.GA4668@in.ibm.com> (raw)
In-Reply-To: <20130311142233.19885.10567.stgit@mhiramat-M0-7522>
On Mon, Mar 11, 2013 at 11:22:33PM +0900, Masami Hiramatsu wrote:
> Beacuse hash_64() is called from the get_kprobe() inside
> int3 handler, kernel causes int3 recursion and crashes if
> kprobes user puts a probe on it.
>
> Usually hash_64() is inlined into caller function, but in
> some cases, it has instances by gcc's interprocedural
> constant propagation.
>
> This patch adds __kprobes tag on the hash_64() and moves
> all those instances into .text.kprobe section so that
> kprobes can refuse probing on the instances.
>
> I've ensured that all hash_64 instances moves to the
> address between __kprobes_text_start and __kprobes_text_end
> with this patch as below.
>
> ffffffff8138bea0 T __kprobes_text_start
> ffffffff8138bec0 t hash_64.constprop.8
> ffffffff8138ef98 t hash_64.constprop.26
> ffffffff8138efae t hash_64
> ffffffff8138f066 t hash_64.constprop.43
> ffffffff8138f649 t hash_64.constprop.25
> ffffffff8139103a t hash_64.constprop.77
> ffffffff81391050 t hash_64.constprop.24
> ffffffff81391066 t hash_64.constprop.40
> ffffffff8139107c t hash_64.constprop.15
> ffffffff81391092 T __kprobes_text_end
>
> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Reported-by: Timo Juhani Lindfors <timo.lindfors@iki.fi>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Nadia Yvette Chambers <nyc@holomorphy.com>
> Cc: Pavel Emelyanov <xemul@parallels.com>
> Cc: Jiri Kosina <jkosina@suse.cz>
> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
next prev parent reply other threads:[~2013-03-12 4:35 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-11 14:22 [PATCH -tip ] [BUGFIX] kprobes: Move hash_64() into .text.kprobe section Masami Hiramatsu
2013-03-12 4:35 ` Ananth N Mavinakayanahalli [this message]
2013-03-12 8:16 ` Ingo Molnar
2013-03-12 11:03 ` Masami Hiramatsu
2013-03-12 8:21 ` Ingo Molnar
2013-03-12 11:07 ` Masami Hiramatsu
2013-03-12 12:09 ` Ingo Molnar
2013-03-12 16:04 ` Linus Torvalds
2013-03-13 6:58 ` Masami Hiramatsu
2013-03-13 13:28 ` Timo Juhani Lindfors
2013-03-13 13:46 ` Masami Hiramatsu
2013-03-18 20:57 ` Timo Juhani Lindfors
2013-03-19 2:53 ` Masami Hiramatsu
2013-03-21 11:39 ` Ingo Molnar
2013-03-21 13:23 ` Masami Hiramatsu
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