From: Borislav Petkov <bp@alien8.de>
To: kbuild-all@lists.01.org
Subject: Re: [PATCH v1 11/19] x86/sev-es: Convert to insn_decode()
Date: Thu, 21 Jan 2021 17:58:45 +0100 [thread overview]
Message-ID: <20210121165845.GD32060@zn.tnic> (raw)
In-Reply-To: <X+ouv0PN6dmva92i@google.com>
[-- Attachment #1: Type: text/plain, Size: 1314 bytes --]
On Mon, Dec 28, 2020 at 11:15:11AM -0800, Sean Christopherson wrote:
> Alternatively, could the kernel case use insn_decode_regs()? If
> vc_fetch_insn_kernel() were also modified to mirror insn_fetch_from_user(), the
> two code paths could be unified except for the the fetch and the PFEC. E.g.
Personal Firearms Eligibility Check?
In any case, I prefer simple, easy to follow code at a quick glance.
Stuff like...
>
> static int vc_fetch_insn_kernel(struct es_em_ctxt *ctxt,
> unsigned char *buffer)
> {
> if (copy_from_kernel_nofault(buffer, (unsigned char *)ctxt->regs->ip, MAX_INSN_SIZE))
> return 0;
>
> return MAX_INSN_SIZE;
> }
>
> static enum es_result vc_decode_insn(struct es_em_ctxt *ctxt)
> {
> char buffer[MAX_INSN_SIZE];
> int nbytes;
>
> if (user_mode(ctxt->regs))
> nbytes = insn_fetch_from_user(ctxt->regs, buffer);
> else
> nbytes = vc_fetch_insn_kernel(ctxt, buffer);
>
> if (!nbytes) {
> ctxt->fi.vector = X86_TRAP_PF;
> ctxt->fi.error_code = X86_PF_INSTR;
> if (user_mode(ctxt->regs))
... this second repeated check here is not what I would call that.
But this is my personal preference only so it's up for a vote now.
:-)
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
WARNING: multiple messages have this Message-ID (diff)
From: Borislav Petkov <bp@alien8.de>
To: Sean Christopherson <seanjc@google.com>
Cc: kernel test robot <lkp@intel.com>,
Andy Lutomirski <luto@amacapital.net>,
Masami Hiramatsu <mhiramat@kernel.org>,
kbuild-all@lists.01.org, clang-built-linux@googlegroups.com,
X86 ML <x86@kernel.org>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v1 11/19] x86/sev-es: Convert to insn_decode()
Date: Thu, 21 Jan 2021 17:58:45 +0100 [thread overview]
Message-ID: <20210121165845.GD32060@zn.tnic> (raw)
In-Reply-To: <X+ouv0PN6dmva92i@google.com>
On Mon, Dec 28, 2020 at 11:15:11AM -0800, Sean Christopherson wrote:
> Alternatively, could the kernel case use insn_decode_regs()? If
> vc_fetch_insn_kernel() were also modified to mirror insn_fetch_from_user(), the
> two code paths could be unified except for the the fetch and the PFEC. E.g.
Personal Firearms Eligibility Check?
In any case, I prefer simple, easy to follow code at a quick glance.
Stuff like...
>
> static int vc_fetch_insn_kernel(struct es_em_ctxt *ctxt,
> unsigned char *buffer)
> {
> if (copy_from_kernel_nofault(buffer, (unsigned char *)ctxt->regs->ip, MAX_INSN_SIZE))
> return 0;
>
> return MAX_INSN_SIZE;
> }
>
> static enum es_result vc_decode_insn(struct es_em_ctxt *ctxt)
> {
> char buffer[MAX_INSN_SIZE];
> int nbytes;
>
> if (user_mode(ctxt->regs))
> nbytes = insn_fetch_from_user(ctxt->regs, buffer);
> else
> nbytes = vc_fetch_insn_kernel(ctxt, buffer);
>
> if (!nbytes) {
> ctxt->fi.vector = X86_TRAP_PF;
> ctxt->fi.error_code = X86_PF_INSTR;
> if (user_mode(ctxt->regs))
... this second repeated check here is not what I would call that.
But this is my personal preference only so it's up for a vote now.
:-)
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2021-01-21 16:58 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-23 17:42 [PATCH v1 00/19] x86/insn: Add an insn_decode() API Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 01/19] x86/insn: Rename insn_decode() to insn_decode_regs() Borislav Petkov
2020-12-28 17:16 ` Sean Christopherson
2020-12-29 19:36 ` Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 02/19] x86/insn: Add @buf_len param to insn_init() kernel-doc comment Borislav Petkov
2020-12-28 1:44 ` Masami Hiramatsu
2020-12-23 17:42 ` [PATCH v1 03/19] x86/insn: Add an insn_decode() API Borislav Petkov
2020-12-28 1:15 ` Masami Hiramatsu
2020-12-29 20:06 ` Borislav Petkov
2020-12-30 9:00 ` Masami Hiramatsu
2020-12-30 9:28 ` Borislav Petkov
2021-01-06 5:21 ` Masami Hiramatsu
2021-01-08 18:59 ` Borislav Petkov
2021-01-12 11:34 ` Masami Hiramatsu
2021-01-13 18:06 ` Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 04/19] x86/insn-eval: Handle return values from the decoder Borislav Petkov
2020-12-28 18:51 ` Sean Christopherson
2020-12-28 19:06 ` Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 05/19] x86/boot/compressed/sev-es: Convert to insn_decode() Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 06/19] perf/x86/intel/ds: Check insn_get_length() retval Borislav Petkov
2021-01-04 13:19 ` Peter Zijlstra
2021-01-19 10:40 ` Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 07/19] perf/x86/intel/ds: Check return values of insn decoder functions Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 08/19] x86/alternative: Use insn_decode() Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 09/19] x86/mce: Convert to insn_decode() Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 10/19] x86/kprobes: " Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 11/19] x86/sev-es: " Borislav Petkov
2020-12-25 10:50 ` kernel test robot
2020-12-25 10:50 ` kernel test robot
2020-12-25 12:33 ` Borislav Petkov
2020-12-25 12:33 ` Borislav Petkov
2020-12-28 19:15 ` Sean Christopherson
2020-12-28 19:15 ` Sean Christopherson
2021-01-21 16:58 ` Borislav Petkov [this message]
2021-01-21 16:58 ` Borislav Petkov
2021-01-21 22:35 ` Sean Christopherson
2021-01-21 22:35 ` Sean Christopherson
2020-12-23 17:42 ` [PATCH v1 12/19] x86/traps: " Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 13/19] x86/uprobes: " Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 14/19] x86/tools/insn_decoder_test: " Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 15/19] tools/objtool: " Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 16/19] x86/tools/insn_sanity: " Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 17/19] tools/perf: " Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 18/19] x86/insn: Remove kernel_insn_init() Borislav Petkov
2020-12-23 17:42 ` [PATCH v1 19/19] x86/insn: Make insn_complete() static Borislav Petkov
2020-12-27 15:26 ` [PATCH v1 00/19] x86/insn: Add an insn_decode() API Tom Lendacky
2021-02-03 12:00 ` 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=20210121165845.GD32060@zn.tnic \
--to=bp@alien8.de \
--cc=kbuild-all@lists.01.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.