From: Heiko Carstens <heiko.carstens@de.ibm.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Kees Cook <keescook@chromium.org>,
"Luis R. Rodriguez" <mcgrof@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
LKML <linux-kernel@vger.kernel.org>,
"x86@kernel.org" <x86@kernel.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Michael Ellerman <mpe@ellerman.id.au>
Subject: Re: [PATCH V2] x86/ftrace: Make sure that ftrace trampolines are not RWX
Date: Fri, 26 May 2017 11:27:16 +0200 [thread overview]
Message-ID: <20170526092716.GA14849@osiris> (raw)
In-Reply-To: <alpine.DEB.2.20.1705260859290.1902@nanos>
On Fri, May 26, 2017 at 09:03:13AM +0200, Thomas Gleixner wrote:
> > It seems like it really should. That would put it in a single place
> > and avoid this mistake again in the future. Does module_memfree() have
> > access to the allocation size, or does that need to get plumbed?
>
> No, it doesn't. But the number of instances is pretty limited.
>
> Btw, looking at BPF. It allocates memory via module_alloc() which means
> it's RWX. There is nothing in that BPF code which changes the permissions
> afterwards ....
For BPF you're probably referring to bpf_jit_binary_alloc()? Permissions
are changed with bpf_jit_binary_lock_ro() within each architecure backend.
Well, except for powerpc (cc'ed Michael).
next prev parent reply other threads:[~2017-05-26 9:28 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-24 13:47 [PATCH] x86/ftrace: Make sure that ftrace trampolines are not RWX Thomas Gleixner
2017-05-24 14:33 ` Masami Hiramatsu
2017-05-24 15:04 ` Steven Rostedt
2017-05-24 17:47 ` Steven Rostedt
2017-05-24 18:16 ` Luis R. Rodriguez
2017-05-24 18:53 ` Thomas Gleixner
2017-05-24 19:34 ` Luis R. Rodriguez
2017-05-24 19:13 ` Thomas Gleixner
2017-05-24 22:25 ` Steven Rostedt
2017-05-24 23:18 ` Luis R. Rodriguez
2017-05-25 6:25 ` Thomas Gleixner
2017-05-25 8:57 ` [PATCH V2] " Thomas Gleixner
2017-05-25 15:15 ` Steven Rostedt
2017-05-25 17:46 ` Luis R. Rodriguez
2017-05-25 19:51 ` Kees Cook
2017-05-26 7:03 ` Thomas Gleixner
2017-05-26 9:27 ` Heiko Carstens [this message]
2017-05-26 9:56 ` Thomas Gleixner
2017-05-26 11:40 ` Michael Ellerman
2017-05-26 9:49 ` Masami Hiramatsu
2017-05-26 13:37 ` Steven Rostedt
2017-05-26 13:50 ` Thomas Gleixner
2017-05-26 13:58 ` Steven Rostedt
2017-05-25 9:09 ` [PATCH] " Masami Hiramatsu
2017-05-25 10:34 ` Masami Hiramatsu
2017-05-25 15:18 ` Steven Rostedt
2017-05-26 1:34 ` Masami Hiramatsu
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