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94a855111e
been long in the making. It is a lighterweight software-only fix for Skylake-based cores where enabling IBRS is a big hammer and causes a significant performance impact. What it basically does is, it aligns all kernel functions to 16 bytes boundary and adds a 16-byte padding before the function, objtool collects all functions' locations and when the mitigation gets applied, it patches a call accounting thunk which is used to track the call depth of the stack at any time. When that call depth reaches a magical, microarchitecture-specific value for the Return Stack Buffer, the code stuffs that RSB and avoids its underflow which could otherwise lead to the Intel variant of Retbleed. This software-only solution brings a lot of the lost performance back, as benchmarks suggest: https://lore.kernel.org/all/20220915111039.092790446@infradead.org/ That page above also contains a lot more detailed explanation of the whole mechanism - Implement a new control flow integrity scheme called FineIBT which is based on the software kCFI implementation and uses hardware IBT support where present to annotate and track indirect branches using a hash to validate them - Other misc fixes and cleanups -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmOZp5EACgkQEsHwGGHe VUrZFxAAvi/+8L0IYSK4mKJvixGbTFjxN/Swo2JVOfs34LqGUT6JaBc+VUMwZxdb VMTFIZ3ttkKEodjhxGI7oGev6V8UfhI37SmO2lYKXpQVjXXnMlv/M+Vw3teE38CN gopi+xtGnT1IeWQ3tc/Tv18pleJ0mh5HKWiW+9KoqgXj0wgF9x4eRYDz1TDCDA/A iaBzs56j8m/FSykZHnrWZ/MvjKNPdGlfJASUCPeTM2dcrXQGJ93+X2hJctzDte0y Nuiw6Y0htfFBE7xoJn+sqm5Okr+McoUM18/CCprbgSKYk18iMYm3ZtAi6FUQZS1A ua4wQCf49loGp15PO61AS5d3OBf5D3q/WihQRbCaJvTVgPp9sWYnWwtcVUuhMllh ZQtBU9REcVJ/22bH09Q9CjBW0VpKpXHveqQdqRDViLJ6v/iI6EFGmD24SW/VxyRd 73k9MBGrL/dOf1SbEzdsnvcSB3LGzp0Om8o/KzJWOomrVKjBCJy16bwTEsCZEJmP i406m92GPXeaN1GhTko7vmF0GnkEdJs1GVCZPluCAxxbhHukyxHnrjlQjI4vC80n Ylc0B3Kvitw7LGJsPqu+/jfNHADC/zhx1qz/30wb5cFmFbN1aRdp3pm8JYUkn+l/ zri2Y6+O89gvE/9/xUhMohzHsWUO7xITiBavewKeTP9GSWybWUs= =cRy1 -----END PGP SIGNATURE----- Merge tag 'x86_core_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 core updates from Borislav Petkov: - Add the call depth tracking mitigation for Retbleed which has been long in the making. It is a lighterweight software-only fix for Skylake-based cores where enabling IBRS is a big hammer and causes a significant performance impact. What it basically does is, it aligns all kernel functions to 16 bytes boundary and adds a 16-byte padding before the function, objtool collects all functions' locations and when the mitigation gets applied, it patches a call accounting thunk which is used to track the call depth of the stack at any time. When that call depth reaches a magical, microarchitecture-specific value for the Return Stack Buffer, the code stuffs that RSB and avoids its underflow which could otherwise lead to the Intel variant of Retbleed. This software-only solution brings a lot of the lost performance back, as benchmarks suggest: https://lore.kernel.org/all/20220915111039.092790446@infradead.org/ That page above also contains a lot more detailed explanation of the whole mechanism - Implement a new control flow integrity scheme called FineIBT which is based on the software kCFI implementation and uses hardware IBT support where present to annotate and track indirect branches using a hash to validate them - Other misc fixes and cleanups * tag 'x86_core_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (80 commits) x86/paravirt: Use common macro for creating simple asm paravirt functions x86/paravirt: Remove clobber bitmask from .parainstructions x86/debug: Include percpu.h in debugreg.h to get DECLARE_PER_CPU() et al x86/cpufeatures: Move X86_FEATURE_CALL_DEPTH from bit 18 to bit 19 of word 11, to leave space for WIP X86_FEATURE_SGX_EDECCSSA bit x86/Kconfig: Enable kernel IBT by default x86,pm: Force out-of-line memcpy() objtool: Fix weak hole vs prefix symbol objtool: Optimize elf_dirty_reloc_sym() x86/cfi: Add boot time hash randomization x86/cfi: Boot time selection of CFI scheme x86/ibt: Implement FineIBT objtool: Add --cfi to generate the .cfi_sites section x86: Add prefix symbols for function padding objtool: Add option to generate prefix symbols objtool: Avoid O(bloody terrible) behaviour -- an ode to libelf objtool: Slice up elf_create_section_symbol() kallsyms: Revert "Take callthunks into account" x86: Unconfuse CONFIG_ and X86_FEATURE_ namespaces x86/retpoline: Fix crash printing warning x86/paravirt: Fix a !PARAVIRT build warning ...
305 lines
7.7 KiB
ArmAsm
305 lines
7.7 KiB
ArmAsm
/*
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* Intel SHA Extensions optimized implementation of a SHA-1 update function
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*
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* This file is provided under a dual BSD/GPLv2 license. When using or
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* redistributing this file, you may do so under either license.
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*
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* GPL LICENSE SUMMARY
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*
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* Copyright(c) 2015 Intel Corporation.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of version 2 of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* Contact Information:
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* Sean Gulley <sean.m.gulley@intel.com>
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* Tim Chen <tim.c.chen@linux.intel.com>
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*
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* BSD LICENSE
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*
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* Copyright(c) 2015 Intel Corporation.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* * Neither the name of Intel Corporation nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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#include <linux/linkage.h>
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#include <linux/cfi_types.h>
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#define DIGEST_PTR %rdi /* 1st arg */
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#define DATA_PTR %rsi /* 2nd arg */
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#define NUM_BLKS %rdx /* 3rd arg */
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/* gcc conversion */
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#define FRAME_SIZE 32 /* space for 2x16 bytes */
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#define ABCD %xmm0
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#define E0 %xmm1 /* Need two E's b/c they ping pong */
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#define E1 %xmm2
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#define MSG0 %xmm3
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#define MSG1 %xmm4
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#define MSG2 %xmm5
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#define MSG3 %xmm6
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#define SHUF_MASK %xmm7
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/*
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* Intel SHA Extensions optimized implementation of a SHA-1 update function
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*
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* The function takes a pointer to the current hash values, a pointer to the
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* input data, and a number of 64 byte blocks to process. Once all blocks have
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* been processed, the digest pointer is updated with the resulting hash value.
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* The function only processes complete blocks, there is no functionality to
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* store partial blocks. All message padding and hash value initialization must
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* be done outside the update function.
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*
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* The indented lines in the loop are instructions related to rounds processing.
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* The non-indented lines are instructions related to the message schedule.
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*
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* void sha1_ni_transform(uint32_t *digest, const void *data,
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uint32_t numBlocks)
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* digest : pointer to digest
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* data: pointer to input data
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* numBlocks: Number of blocks to process
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*/
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.text
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SYM_TYPED_FUNC_START(sha1_ni_transform)
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push %rbp
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mov %rsp, %rbp
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sub $FRAME_SIZE, %rsp
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and $~0xF, %rsp
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shl $6, NUM_BLKS /* convert to bytes */
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jz .Ldone_hash
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add DATA_PTR, NUM_BLKS /* pointer to end of data */
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/* load initial hash values */
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pinsrd $3, 1*16(DIGEST_PTR), E0
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movdqu 0*16(DIGEST_PTR), ABCD
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pand UPPER_WORD_MASK(%rip), E0
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pshufd $0x1B, ABCD, ABCD
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movdqa PSHUFFLE_BYTE_FLIP_MASK(%rip), SHUF_MASK
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.Lloop0:
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/* Save hash values for addition after rounds */
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movdqa E0, (0*16)(%rsp)
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movdqa ABCD, (1*16)(%rsp)
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/* Rounds 0-3 */
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movdqu 0*16(DATA_PTR), MSG0
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pshufb SHUF_MASK, MSG0
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paddd MSG0, E0
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movdqa ABCD, E1
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sha1rnds4 $0, E0, ABCD
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/* Rounds 4-7 */
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movdqu 1*16(DATA_PTR), MSG1
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pshufb SHUF_MASK, MSG1
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sha1nexte MSG1, E1
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movdqa ABCD, E0
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sha1rnds4 $0, E1, ABCD
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sha1msg1 MSG1, MSG0
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/* Rounds 8-11 */
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movdqu 2*16(DATA_PTR), MSG2
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pshufb SHUF_MASK, MSG2
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sha1nexte MSG2, E0
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movdqa ABCD, E1
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sha1rnds4 $0, E0, ABCD
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sha1msg1 MSG2, MSG1
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pxor MSG2, MSG0
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/* Rounds 12-15 */
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movdqu 3*16(DATA_PTR), MSG3
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pshufb SHUF_MASK, MSG3
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sha1nexte MSG3, E1
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movdqa ABCD, E0
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sha1msg2 MSG3, MSG0
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sha1rnds4 $0, E1, ABCD
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sha1msg1 MSG3, MSG2
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pxor MSG3, MSG1
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/* Rounds 16-19 */
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sha1nexte MSG0, E0
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movdqa ABCD, E1
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sha1msg2 MSG0, MSG1
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sha1rnds4 $0, E0, ABCD
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sha1msg1 MSG0, MSG3
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pxor MSG0, MSG2
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/* Rounds 20-23 */
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sha1nexte MSG1, E1
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movdqa ABCD, E0
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sha1msg2 MSG1, MSG2
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sha1rnds4 $1, E1, ABCD
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sha1msg1 MSG1, MSG0
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pxor MSG1, MSG3
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/* Rounds 24-27 */
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sha1nexte MSG2, E0
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movdqa ABCD, E1
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sha1msg2 MSG2, MSG3
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sha1rnds4 $1, E0, ABCD
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sha1msg1 MSG2, MSG1
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pxor MSG2, MSG0
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/* Rounds 28-31 */
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sha1nexte MSG3, E1
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movdqa ABCD, E0
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sha1msg2 MSG3, MSG0
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sha1rnds4 $1, E1, ABCD
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sha1msg1 MSG3, MSG2
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pxor MSG3, MSG1
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/* Rounds 32-35 */
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sha1nexte MSG0, E0
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movdqa ABCD, E1
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sha1msg2 MSG0, MSG1
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sha1rnds4 $1, E0, ABCD
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sha1msg1 MSG0, MSG3
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pxor MSG0, MSG2
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/* Rounds 36-39 */
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sha1nexte MSG1, E1
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movdqa ABCD, E0
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sha1msg2 MSG1, MSG2
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sha1rnds4 $1, E1, ABCD
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sha1msg1 MSG1, MSG0
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pxor MSG1, MSG3
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/* Rounds 40-43 */
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sha1nexte MSG2, E0
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movdqa ABCD, E1
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sha1msg2 MSG2, MSG3
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sha1rnds4 $2, E0, ABCD
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sha1msg1 MSG2, MSG1
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pxor MSG2, MSG0
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/* Rounds 44-47 */
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sha1nexte MSG3, E1
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movdqa ABCD, E0
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sha1msg2 MSG3, MSG0
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sha1rnds4 $2, E1, ABCD
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sha1msg1 MSG3, MSG2
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pxor MSG3, MSG1
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/* Rounds 48-51 */
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sha1nexte MSG0, E0
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movdqa ABCD, E1
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sha1msg2 MSG0, MSG1
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sha1rnds4 $2, E0, ABCD
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sha1msg1 MSG0, MSG3
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pxor MSG0, MSG2
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/* Rounds 52-55 */
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sha1nexte MSG1, E1
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movdqa ABCD, E0
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sha1msg2 MSG1, MSG2
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sha1rnds4 $2, E1, ABCD
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sha1msg1 MSG1, MSG0
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pxor MSG1, MSG3
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/* Rounds 56-59 */
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sha1nexte MSG2, E0
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movdqa ABCD, E1
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sha1msg2 MSG2, MSG3
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sha1rnds4 $2, E0, ABCD
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sha1msg1 MSG2, MSG1
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pxor MSG2, MSG0
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/* Rounds 60-63 */
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sha1nexte MSG3, E1
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movdqa ABCD, E0
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sha1msg2 MSG3, MSG0
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sha1rnds4 $3, E1, ABCD
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sha1msg1 MSG3, MSG2
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pxor MSG3, MSG1
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/* Rounds 64-67 */
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sha1nexte MSG0, E0
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movdqa ABCD, E1
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sha1msg2 MSG0, MSG1
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sha1rnds4 $3, E0, ABCD
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sha1msg1 MSG0, MSG3
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pxor MSG0, MSG2
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/* Rounds 68-71 */
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sha1nexte MSG1, E1
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movdqa ABCD, E0
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sha1msg2 MSG1, MSG2
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sha1rnds4 $3, E1, ABCD
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pxor MSG1, MSG3
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/* Rounds 72-75 */
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sha1nexte MSG2, E0
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movdqa ABCD, E1
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sha1msg2 MSG2, MSG3
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sha1rnds4 $3, E0, ABCD
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/* Rounds 76-79 */
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sha1nexte MSG3, E1
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movdqa ABCD, E0
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sha1rnds4 $3, E1, ABCD
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/* Add current hash values with previously saved */
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sha1nexte (0*16)(%rsp), E0
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paddd (1*16)(%rsp), ABCD
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/* Increment data pointer and loop if more to process */
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add $64, DATA_PTR
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cmp NUM_BLKS, DATA_PTR
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jne .Lloop0
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/* Write hash values back in the correct order */
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pshufd $0x1B, ABCD, ABCD
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movdqu ABCD, 0*16(DIGEST_PTR)
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pextrd $3, E0, 1*16(DIGEST_PTR)
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.Ldone_hash:
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mov %rbp, %rsp
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pop %rbp
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RET
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SYM_FUNC_END(sha1_ni_transform)
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.section .rodata.cst16.PSHUFFLE_BYTE_FLIP_MASK, "aM", @progbits, 16
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.align 16
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PSHUFFLE_BYTE_FLIP_MASK:
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.octa 0x000102030405060708090a0b0c0d0e0f
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.section .rodata.cst16.UPPER_WORD_MASK, "aM", @progbits, 16
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.align 16
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UPPER_WORD_MASK:
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.octa 0xFFFFFFFF000000000000000000000000
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