From: "H.J. Lu" <hjl.tools@gmail.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: kirill.yukhin@intel.com, Binutils <binutils@sourceware.org>
Subject: Re: [PATCH 2/6] x86/MPX: fix address size handling
Date: Tue, 08 Oct 2013 15:15:00 -0000 [thread overview]
Message-ID: <CAMe9rOrZuQRgcaUNgex=MDFjKYxsJimK1aCMqzEyM2XbZXCo4w@mail.gmail.com> (raw)
In-Reply-To: <525435BC02000078000F9A51@nat28.tlf.novell.com>
On Tue, Oct 8, 2013 at 7:41 AM, Jan Beulich <JBeulich@suse.com> wrote:
> While address overrides are ignored in 64-bit mode (and hence shouldn't
> result in an error), trying to use 16-bit addressing is documented to
> result in #UD, and hence the assembler should reject the attempt.
>
> gas/
> 2013-10-08 Jan Beulich <jbeulich@suse.com>
>
> * tc-i386.c (md_assemble): Alter address size checking for MPX
> instructions.
>
> --- 2013-10-07/gas/config/tc-i386.c
> +++ 2013-10-07/gas/config/tc-i386.c
> @@ -3549,10 +3549,15 @@ md_assemble (char *line)
> if (i.bnd_prefix && !i.tm.opcode_modifier.bndprefixok)
> as_bad (_("expecting valid branch instruction after `bnd'"));
>
> - if (i.tm.cpu_flags.bitfield.cpumpx
> - && flag_code == CODE_64BIT
> - && i.prefix[ADDR_PREFIX])
> - as_bad (_("32-bit address isn't allowed in 64-bit MPX instructions."));
It is done on purpose. When 32-bit address prefix in 64-bit is ignored,
MPX doesn't work correctly for x32.
> + if (i.tm.cpu_flags.bitfield.cpumpx)
> + {
> + if (flag_code == CODE_64BIT && i.prefix[ADDR_PREFIX])
> + as_warn (_("32-bit addressing is ignored in 64-bit MPX instructions"));
> + else if (flag_code != CODE_16BIT
> + ? i.prefix[ADDR_PREFIX]
> + : i.mem_operands && !i.prefix[ADDR_PREFIX])
> + as_bad (_("16-bit addressing isn't allowed in MPX instructions"));
> + }
>
> /* Insert BND prefix. */
> if (add_bnd_prefix
>
>
>
--
H.J.
next prev parent reply other threads:[~2013-10-08 15:15 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-08 14:36 [PATCH 0/6] x86: various MPX fixes Jan Beulich
2013-10-08 14:41 ` [PATCH 1/6] x86/MPX: testsuite adjustments Jan Beulich
2013-10-08 14:41 ` [PATCH 2/6] x86/MPX: fix address size handling Jan Beulich
2013-10-08 15:15 ` H.J. Lu [this message]
2013-10-08 15:20 ` Jan Beulich
2013-10-08 15:32 ` H.J. Lu
2013-10-09 7:30 ` Jan Beulich
2013-10-09 15:45 ` H.J. Lu
2013-10-10 12:27 ` Jan Beulich
2013-10-10 15:18 ` H.J. Lu
2013-10-08 14:42 ` [PATCH 3/6] x86/MPX: suppress base/index swapping in Intel mode for bndmk, bndldx, and bndstx Jan Beulich
2013-10-08 15:16 ` H.J. Lu
2013-10-08 15:23 ` Jan Beulich
2013-10-08 15:34 ` H.J. Lu
2013-10-08 16:00 ` Jan Beulich
2013-10-08 16:19 ` H.J. Lu
2013-10-09 7:15 ` acceptance rules (was: Re: [PATCH 3/6] x86/MPX: suppress base/index swapping ...) Jan Beulich
2013-10-09 16:45 ` H.J. Lu
2013-10-08 14:43 ` [PATCH 4/6] x86/MPX: bndmk, bndldx, and bndstx only allow a memory operand Jan Beulich
2013-10-08 15:28 ` H.J. Lu
2013-10-09 7:24 ` Jan Beulich
2013-10-09 15:17 ` H.J. Lu
2013-10-08 14:43 ` [PATCH 5/6] x86/MPX: fix operand size handling Jan Beulich
2013-10-08 15:45 ` H.J. Lu
2013-10-09 7:36 ` Jan Beulich
2013-10-09 15:51 ` H.J. Lu
2013-10-10 13:14 ` Jan Beulich
2013-10-10 15:14 ` H.J. Lu
2013-10-12 15:58 ` H.J. Lu
2013-10-12 17:12 ` H.J. Lu
2013-10-08 14:44 ` [PATCH 6/6] x86/MPX: bndmk, bndldx, and bndstx don't allow RIP-relative addressing Jan Beulich
2013-10-08 16:13 ` H.J. Lu
2013-10-09 7:40 ` Jan Beulich
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