From: Borislav Petkov <bp@alien8.de>
To: Masami Hiramatsu <mhiramat@kernel.org>
Cc: x86-ml <x86@kernel.org>, Joerg Roedel <jroedel@suse.de>,
lkml <linux-kernel@vger.kernel.org>
Subject: Re: [RFC] Have insn decoder functions return success/failure
Date: Fri, 23 Oct 2020 11:17:55 +0200 [thread overview]
Message-ID: <20201023091755.GA23324@zn.tnic> (raw)
In-Reply-To: <20201022222140.f46e6db1243e05fdd049b504@kernel.org>
On Thu, Oct 22, 2020 at 10:21:40PM +0900, Masami Hiramatsu wrote:
> extern void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64);
> extern void insn_get_prefixes(struct insn *insn);
> extern void insn_get_opcode(struct insn *insn);
> extern void insn_get_modrm(struct insn *insn);
> extern void insn_get_sib(struct insn *insn);
> extern void insn_get_displacement(struct insn *insn);
> extern void insn_get_immediate(struct insn *insn);
> extern void insn_get_length(struct insn *insn);
...
> Ah, so you meant that we don't need such a different insn_get_* APIs,
> but a single insn_decode() API, which will decode all fields.
> (IOW, alias of insn_init() and insn_get_length(), right?)
Yes, so there should be a balance between what one wants to decode:
length, opcodes, etc
vs
when one needs only a certain *single* aspect: sib, length,
displacement, etc.
So if you need a couple of things, you can simply call the insn_decode()
function - I'm reading forward and I like your naming :) - and when
that returns success, you can be sure that struct insn contains all the
fields needed.
Otherwise...
> > If there are specialized uses, you can call some of the insn_get_*
> > helpers if you're not interested in decoding the full insn.
>
> OK, agreed.
... yes, exactly!
> > But if simply calling insn_decode_insn() would give you everything and
> > that is not that expensive, we can do that - API simplicity.
>
> I rather like simple "insn_decode()" function, no need to repeat
> insn again.
>
> int insn_decode(struct insn *insn, const void *kaddr, int buf_len, bool x86_64);
Yap, good.
Ok, seems we agree, lemme poke at this one more time, convert some users
and we can see how it looks like and talk then.
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2020-10-23 9:18 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-20 12:02 [RFC] Have insn decoder functions return success/failure Borislav Petkov
2020-10-20 14:27 ` Masami Hiramatsu
2020-10-20 14:37 ` Borislav Petkov
2020-10-21 0:50 ` Masami Hiramatsu
2020-10-21 9:27 ` Borislav Petkov
2020-10-21 14:26 ` Masami Hiramatsu
2020-10-21 16:45 ` Borislav Petkov
2020-10-22 7:31 ` Masami Hiramatsu
2020-10-22 9:30 ` Borislav Petkov
2020-10-22 13:21 ` Masami Hiramatsu
2020-10-22 17:58 ` Andy Lutomirski
2020-10-23 9:20 ` Borislav Petkov
2020-10-23 9:28 ` Masami Hiramatsu
2020-10-23 9:32 ` Borislav Petkov
2020-10-23 10:47 ` Masami Hiramatsu
2020-10-23 23:27 ` Borislav Petkov
2020-10-24 0:12 ` Andy Lutomirski
2020-10-24 7:21 ` Masami Hiramatsu
2020-10-24 8:23 ` Borislav Petkov
2020-10-24 16:10 ` Andy Lutomirski
2020-10-27 13:42 ` Borislav Petkov
2020-10-28 11:36 ` Masami Hiramatsu
2020-10-24 7:13 ` Masami Hiramatsu
2020-10-24 8:24 ` Borislav Petkov
2020-10-29 12:42 ` Borislav Petkov
2020-10-30 1:24 ` Masami Hiramatsu
2020-10-30 13:07 ` Borislav Petkov
2020-10-23 9:17 ` Borislav Petkov [this message]
2020-10-22 8:04 ` Peter Zijlstra
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