From: Wei Liu <wei.liu2@citrix.com>
To: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: "Wei Liu" <wei.liu2@citrix.com>,
"Roger Pau Monné" <roger.pau@citrix.com>,
"Jan Beulich" <JBeulich@suse.com>,
Xen-devel <xen-devel@lists.xen.org>
Subject: Re: [PATCH 4/7] x86/asm: Remove opencoded uses of altinstruction_entry
Date: Mon, 12 Feb 2018 12:30:44 +0000 [thread overview]
Message-ID: <20180212123044.2nih6z65fp254oyq@citrix.com> (raw)
In-Reply-To: <1518434587-22827-5-git-send-email-andrew.cooper3@citrix.com>
On Mon, Feb 12, 2018 at 11:23:04AM +0000, Andrew Cooper wrote:
> diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S
> index 58f652d..bd3819a 100644
> --- a/xen/arch/x86/x86_64/entry.S
> +++ b/xen/arch/x86/x86_64/entry.S
> @@ -557,23 +557,9 @@ handle_exception_saved:
> testb $X86_EFLAGS_IF>>8,UREGS_eflags+1(%rsp)
> jz exception_with_ints_disabled
>
> -.Lcr4_pv32_orig:
> - jmp .Lcr4_pv32_done
> - .skip (.Lcr4_pv32_alt_end - .Lcr4_pv32_alt) - (. - .Lcr4_pv32_orig), 0xcc
> - .pushsection .altinstr_replacement, "ax"
> -.Lcr4_pv32_alt:
> - mov VCPU_domain(%rbx),%rax
> -.Lcr4_pv32_alt_end:
> - .section .altinstructions, "a"
> - altinstruction_entry .Lcr4_pv32_orig, .Lcr4_pv32_alt, \
> - X86_FEATURE_XEN_SMEP, \
> - (.Lcr4_pv32_alt_end - .Lcr4_pv32_alt), \
> - (.Lcr4_pv32_alt_end - .Lcr4_pv32_alt)
> - altinstruction_entry .Lcr4_pv32_orig, .Lcr4_pv32_alt, \
> - X86_FEATURE_XEN_SMAP, \
> - (.Lcr4_pv32_alt_end - .Lcr4_pv32_alt), \
> - (.Lcr4_pv32_alt_end - .Lcr4_pv32_alt)
> - .popsection
> + ALTERNATIVE_2 "jmp .Lcr4_pv32_done; .skip 2, 0x90", \
This changed 0xcc to 0x90 but since it is just padding following an
unconditional jmp so it shouldn't matter.
Mostly looks fine. I'm a bit hesitant to give my Rb because reviewing
the diff to assembly is a bit more difficult to than diff to C source.
Do you have a branch somewhere?
Wei.
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next prev parent reply other threads:[~2018-02-12 12:30 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-12 11:23 [PATCH 0/7] x86/alternatives: Support for automatic padding calculations Andrew Cooper
2018-02-12 11:23 ` [PATCH 1/7] x86/alt: Drop unused alternative infrastructure Andrew Cooper
2018-02-12 12:30 ` Wei Liu
2018-02-12 15:56 ` Roger Pau Monné
2018-02-12 15:58 ` Andrew Cooper
2018-02-13 14:22 ` Jan Beulich
2018-02-13 14:41 ` Andrew Cooper
2018-02-13 15:33 ` Jan Beulich
2018-02-14 10:02 ` Jan Beulich
2018-02-12 11:23 ` [PATCH 2/7] x86/alt: Clean up struct alt_instr and its users Andrew Cooper
2018-02-12 12:30 ` Wei Liu
2018-02-12 16:52 ` Roger Pau Monné
2018-02-12 17:18 ` Wei Liu
2018-02-12 17:53 ` Andrew Cooper
2018-02-13 14:26 ` Jan Beulich
2018-02-21 21:22 ` Konrad Rzeszutek Wilk
2018-02-12 11:23 ` [PATCH 3/7] x86/alt: Clean up the assembly used to generate alternatives Andrew Cooper
2018-02-12 12:30 ` Wei Liu
2018-02-12 17:26 ` Roger Pau Monné
2018-02-12 17:54 ` Andrew Cooper
2018-02-13 14:37 ` Jan Beulich
2018-02-23 14:03 ` Andrew Cooper
2018-02-23 15:12 ` Jan Beulich
2018-02-23 16:24 ` Andrew Cooper
2018-02-23 17:28 ` Jan Beulich
2018-02-12 11:23 ` [PATCH 4/7] x86/asm: Remove opencoded uses of altinstruction_entry Andrew Cooper
2018-02-12 12:30 ` Wei Liu [this message]
2018-02-12 12:34 ` Andrew Cooper
2018-02-13 9:56 ` Jan Beulich
2018-02-13 10:07 ` Andrew Cooper
2018-02-13 11:10 ` Jan Beulich
2018-02-12 12:52 ` Wei Liu
2018-02-12 17:46 ` Roger Pau Monné
2018-02-12 17:59 ` Andrew Cooper
2018-02-14 9:53 ` Jan Beulich
2018-02-12 11:23 ` [PATCH 5/7] x86/alt: Support for automatic padding calculations Andrew Cooper
2018-02-12 14:39 ` Wei Liu
2018-02-12 15:04 ` Andrew Cooper
2018-02-12 18:41 ` Roger Pau Monné
2018-02-12 18:45 ` Andrew Cooper
2018-02-12 18:09 ` Roger Pau Monné
2018-02-13 9:45 ` Roger Pau Monné
2018-02-13 10:09 ` Andrew Cooper
2018-02-13 10:26 ` Roger Pau Monné
2018-02-14 9:46 ` Jan Beulich
2018-02-12 11:23 ` [PATCH 6/7] x86/alt: Drop explicit padding of origin sites Andrew Cooper
2018-02-12 14:39 ` Wei Liu
2018-02-12 18:12 ` Roger Pau Monné
2018-02-14 9:53 ` Jan Beulich
2018-02-12 11:23 ` [PATCH 7/7] x86/build: Use new .nop directive when available Andrew Cooper
2018-02-12 14:40 ` Wei Liu
2018-02-13 11:08 ` Roger Pau Monné
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