From: Borislav Petkov <bp@alien8.de>
To: Andy Lutomirski <luto@amacapital.net>,
Masami Hiramatsu <mhiramat@kernel.org>
Cc: X86 ML <x86@kernel.org>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH v0 00/19] x86/insn: Add an insn_decode() API
Date: Tue, 24 Nov 2020 18:46:47 +0100 [thread overview]
Message-ID: <20201124174647.GI4009@zn.tnic> (raw)
In-Reply-To: <20201124101952.7909-1-bp@alien8.de>
On Tue, Nov 24, 2020 at 11:19:33AM +0100, Borislav Petkov wrote:
> In any case, at least the case where I give it
>
> 0x48 0xcf 0x48 0x83
>
> and say that buf size is 4, should return an error because the second
> insn is incomplete. So I need to go look at that now.
Ok, got it:
./arch/x86/tools/insn_sanity: Success: decoded and checked 10000 random instructions with 0 errors (seed:0x826fdf9c)
insn buffer:
0x48 0xcf 0x48 0x83 0x90 0x90 0x90 0x90 0x90 0x90 0x90 0x90 0x90 0x90 0x90
supplied buf size: 15, ret 0
supplied buf size: 2, ret 0
supplied buf size: 3, ret 0
supplied buf size: 4, ret 0
supplied buf size: 1, ret -22
the current decoder simply decodes the *first* insn in the buffer it
encounters and that's it.
When you give it a buffer of size smaller than the first instruction:
supplied buf size: 1, ret -22
while the first insn is 2 bytes long:
0x48 0xcf (IRETQ)
then it signals an error.
Andy, does that work for your use cases?
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2020-11-24 17:47 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-24 10:19 [RFC PATCH v0 00/19] x86/insn: Add an insn_decode() API Borislav Petkov
2020-11-24 10:19 ` [RFC PATCH v0 01/19] x86/insn: Rename insn_decode() to insn_decode_regs() Borislav Petkov
2020-11-24 10:19 ` [RFC PATCH v0 02/19] x86/insn: Add @buf_len param to insn_init() kernel-doc comment Borislav Petkov
2020-11-24 10:19 ` [RFC PATCH v0 03/19] x86/insn: Add an insn_decode() API Borislav Petkov
2020-11-25 16:53 ` Masami Hiramatsu
2020-11-25 19:25 ` Borislav Petkov
2020-11-26 1:37 ` Masami Hiramatsu
2020-11-26 17:50 ` Borislav Petkov
2020-11-27 5:54 ` Masami Hiramatsu
2020-11-24 10:19 ` [RFC PATCH v0 04/19] x86/insn-eval: Handle return values from the decoder Borislav Petkov
2020-11-24 10:19 ` [RFC PATCH v0 05/19] x86/boot/compressed/sev-es: Convert to insn_decode() Borislav Petkov
2020-11-24 10:19 ` [RFC PATCH v0 06/19] perf/x86/intel/ds: Check insn_get_length() retval Borislav Petkov
2020-11-24 10:19 ` [RFC PATCH v0 07/19] perf/x86/intel/ds: Check return values of insn decoder functions Borislav Petkov
2020-11-24 10:19 ` [RFC PATCH v0 08/19] x86/alternative: Use insn_decode() Borislav Petkov
2020-11-24 10:19 ` [RFC PATCH v0 09/19] x86/mce: Convert to insn_decode() Borislav Petkov
2020-11-24 10:19 ` [RFC PATCH v0 10/19] x86/kprobes: " Borislav Petkov
2020-11-25 17:19 ` Masami Hiramatsu
2020-11-24 10:19 ` [RFC PATCH v0 11/19] x86/sev-es: " Borislav Petkov
2020-11-24 10:19 ` [RFC PATCH v0 12/19] x86/traps: " Borislav Petkov
2020-11-24 10:19 ` [RFC PATCH v0 13/19] x86/uprobes: " Borislav Petkov
2020-11-24 10:19 ` [RFC PATCH v0 14/19] x86/tools/insn_decoder_test: " Borislav Petkov
2020-11-24 10:19 ` [RFC PATCH v0 15/19] tools/objtool: " Borislav Petkov
2020-11-24 10:19 ` [RFC PATCH v0 16/19] x86/tools/insn_sanity: " Borislav Petkov
2020-11-24 10:19 ` [RFC PATCH v0 17/19] tools/perf: " Borislav Petkov
2020-11-24 10:19 ` [RFC PATCH v0 18/19] x86/insn: Remove kernel_insn_init() Borislav Petkov
2020-11-24 10:19 ` [RFC PATCH v0 19/19] x86/insn: Make insn_complete() static Borislav Petkov
2020-11-24 17:46 ` Borislav Petkov [this message]
2020-11-25 8:03 ` [RFC PATCH v0 00/19] x86/insn: Add an insn_decode() API Masami Hiramatsu
2020-11-27 17:45 ` Andy Lutomirski
2020-11-27 22:35 ` Borislav Petkov
2020-11-29 8:50 ` Masami Hiramatsu
2020-11-30 13:44 ` Borislav Petkov
2020-11-30 17:21 ` Masami Hiramatsu
2020-12-02 18:04 ` Borislav Petkov
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=20201124174647.GI4009@zn.tnic \
--to=bp@alien8.de \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@amacapital.net \
--cc=mhiramat@kernel.org \
--cc=x86@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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox