From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: tglx@linutronix.de, linux-kernel@vger.kernel.org, x86@kernel.org
Subject: Re: [RFC][PATCH 00/16] objtool: vmlinux.o and noinstr validation
Date: Sun, 15 Mar 2020 13:12:56 -0500 [thread overview]
Message-ID: <20200315181256.dwj6izb7mdb3v7bq@treble> (raw)
In-Reply-To: <20200312134107.700205216@infradead.org>
On Thu, Mar 12, 2020 at 02:41:07PM +0100, Peter Zijlstra wrote:
> Hi all,
>
> These patches extend objtool to be able to run on vmlinux.o and validate
> Thomas's proposed noinstr annotation:
>
> https://lkml.kernel.org/r/20200310170951.87c29e9c1cfbddd93ccd92b3@kernel.org
>
> "That's why we want the sections and the annotation. If something calls
> out of a noinstr section into a regular text section and the call is not
> annotated at the call site, then objtool can complain and tell you. What
> Peter and I came up with looks like this:
>
> noinstr foo()
> do_protected(); <- Safe because in the noinstr section
> instr_begin(); <- Marks the begin of a safe region, ignored
> by objtool
> do_stuff(); <- All good
> instr_end(); <- End of the safe region. objtool starts
> looking again
> do_other_stuff(); <- Unsafe because do_other_stuff() is
> not protected
>
> and:
>
> noinstr do_protected()
> bar(); <- objtool will complain here
> "
>
> It should be accompanied by something like the below; which you'll find in a
> series by Thomas.
Awesome work!
This is also a big step towards other eventual objtool features, like
LTO compatibility.
I did have a few concerns about the overall "noinstr" implementation,
mentioned in my reply to patch 15.
Other than that, and the minor comments I sent, the code looks great.
--
Josh
prev parent reply other threads:[~2020-03-15 18:13 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-12 13:41 [RFC][PATCH 00/16] objtool: vmlinux.o and noinstr validation Peter Zijlstra
2020-03-12 13:41 ` [RFC][PATCH 01/16] objtool: Introduce validate_return() Peter Zijlstra
2020-03-12 13:41 ` [RFC][PATCH 02/16] objtool: Rename func_for_each_insn() Peter Zijlstra
2020-03-12 13:41 ` [RFC][PATCH 03/16] objtool: Rename func_for_each_insn_all() Peter Zijlstra
2020-03-12 13:41 ` [RFC][PATCH 04/16] objtool: Annotate identity_mapped() Peter Zijlstra
2020-03-13 14:34 ` Peter Zijlstra
2020-03-15 15:45 ` Josh Poimboeuf
2020-03-13 16:46 ` Brian Gerst
2020-03-13 17:22 ` Peter Zijlstra
2020-03-12 13:41 ` [RFC][PATCH 05/16] objtool: Optimize find_symbol_by_index() Peter Zijlstra
2020-03-15 16:09 ` Josh Poimboeuf
2020-03-15 16:18 ` Josh Poimboeuf
2020-03-15 16:10 ` Josh Poimboeuf
2020-03-17 11:55 ` Miroslav Benes
2020-03-17 14:08 ` Peter Zijlstra
2020-03-12 13:41 ` [RFC][PATCH 06/16] objtool: Add a statistics mode Peter Zijlstra
2020-03-15 16:20 ` Josh Poimboeuf
2020-03-12 13:41 ` [RFC][PATCH 07/16] objtool: Optimize find_section_by_index() Peter Zijlstra
2020-03-15 16:24 ` Josh Poimboeuf
2020-03-12 13:41 ` [RFC][PATCH 08/16] Optimize find_section_by_name() Peter Zijlstra
2020-03-15 16:25 ` Josh Poimboeuf
2020-03-17 12:22 ` Miroslav Benes
2020-03-17 14:10 ` Peter Zijlstra
2020-03-12 13:41 ` [RFC][PATCH 09/16] objtool: Optimize find_symbol_*() and read_symbols() Peter Zijlstra
2020-03-15 15:48 ` Josh Poimboeuf
2020-03-15 16:41 ` Josh Poimboeuf
2020-03-12 13:41 ` [RFC][PATCH 10/16] objtool: Resize insn_hash Peter Zijlstra
2020-03-12 13:41 ` [RFC][PATCH 11/16] objtool: Optimize find_symbol_by_name() Peter Zijlstra
2020-03-12 13:41 ` [RFC][PATCH 12/16] objtool: Optimize read_sections() Peter Zijlstra
2020-03-15 16:53 ` Josh Poimboeuf
2020-03-12 13:41 ` [RFC][PATCH 13/16] objtool: Delete cleanup() Peter Zijlstra
2020-03-12 13:41 ` [RFC][PATCH 14/16] objtool: Optimize find_rela_by_dest_range() Peter Zijlstra
2020-03-12 13:41 ` [RFC][PATCH 15/16] objtool: Implement noinstr validation Peter Zijlstra
2020-03-15 18:03 ` Josh Poimboeuf
2020-03-16 13:24 ` Peter Zijlstra
2020-03-16 16:19 ` Josh Poimboeuf
2020-03-16 16:21 ` Josh Poimboeuf
2020-03-16 16:46 ` Peter Zijlstra
2020-03-16 16:48 ` Peter Zijlstra
2020-03-16 19:20 ` Josh Poimboeuf
2020-03-12 13:41 ` [RFC][PATCH 16/16] objtool: Optimize !vmlinux.o again Peter Zijlstra
2020-03-12 21:57 ` [RFC][PATCH v2 " Peter Zijlstra
2020-03-12 16:23 ` [RFC][PATCH 00/16] objtool: vmlinux.o and noinstr validation Peter Zijlstra
2020-03-12 17:44 ` Josh Poimboeuf
2020-03-12 22:23 ` Peter Zijlstra
2020-03-17 0:56 ` Masami Hiramatsu
2020-03-17 9:26 ` Thomas Gleixner
2020-03-17 14:20 ` Masami Hiramatsu
2020-03-17 12:14 ` Peter Zijlstra
2020-03-15 18:12 ` Josh Poimboeuf [this message]
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