Commit 4d448714 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

arm: remove "optimized" SHA1 routines 



Since commit 1eb19a12 ("lib/sha1: use the git implementation of
SHA-1"), the ARM SHA1 routines no longer work.  The reason? They
depended on the larger 320-byte workspace, and now the sha1 workspace is
just 16 words (64 bytes).  So the assembly version would overwrite the
stack randomly.

The optimized asm version is also probably slower than the new improved
C version, so there's no reason to keep it around.  At least that was
the case in git, where what appears to be the same assembly language
version was removed two years ago because the optimized C BLK_SHA1 code
was faster.

Reported-and-tested-by: default avatarJoachim Eastwood <manabian@gmail.com>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Cc: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 32955148

arch/arm/lib/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -12,7 +12,7 @@ lib-y := backtrace.o changebit.o csumipv6.o csumpartial.o \ 
		   strchr.o strrchr.o                                 \

		   testchangebit.o testclearbit.o testsetbit.o        \

		   ashldi3.o ashrdi3.o lshrdi3.o muldi3.o             \

		   ucmpdi2.o lib1funcs.o div64.o sha1.o               \

		   ucmpdi2.o lib1funcs.o div64.o                      \

		   io-readsb.o io-writesb.o io-readsl.o io-writesl.o



mmu-y	:= clear_user.o copy_page.o getuser.o putuser.o

arch/arm/lib/sha1.S

deleted100644 → 0
+0 −211
Original line number Diff line number Diff line 
/*

 *  linux/arch/arm/lib/sha1.S

 *

 *  SHA transform optimized for ARM

 *

 *  Copyright:	(C) 2005 by Nicolas Pitre <nico@fluxnic.net>

 *  Created:	September 17, 2005

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License version 2 as

 *  published by the Free Software Foundation.

 *

 *  The reference implementation for this code is linux/lib/sha1.c

 */



#include <linux/linkage.h>



	.text





/*

 * void sha_transform(__u32 *digest, const char *in, __u32 *W)

 *

 * Note: the "in" ptr may be unaligned.

 */



ENTRY(sha_transform)



	stmfd	sp!, {r4 - r8, lr}



	@ for (i = 0; i < 16; i++)

	@         W[i] = be32_to_cpu(in[i]);



#ifdef __ARMEB__

	mov	r4, r0

	mov	r0, r2

	mov	r2, #64

	bl	memcpy

	mov	r2, r0

	mov	r0, r4

#else

	mov	r3, r2

	mov	lr, #16

1:	ldrb	r4, [r1], #1

	ldrb	r5, [r1], #1

	ldrb	r6, [r1], #1

	ldrb	r7, [r1], #1

	subs	lr, lr, #1

	orr	r5, r5, r4, lsl #8

	orr	r6, r6, r5, lsl #8

	orr	r7, r7, r6, lsl #8

	str	r7, [r3], #4

	bne	1b

#endif



	@ for (i = 0; i < 64; i++)

	@         W[i+16] = ror(W[i+13] ^ W[i+8] ^ W[i+2] ^ W[i], 31);



	sub	r3, r2, #4

	mov	lr, #64

2:	ldr	r4, [r3, #4]!

	subs	lr, lr, #1

	ldr	r5, [r3, #8]

	ldr	r6, [r3, #32]

	ldr	r7, [r3, #52]

	eor	r4, r4, r5

	eor	r4, r4, r6

	eor	r4, r4, r7

	mov	r4, r4, ror #31

	str	r4, [r3, #64]

	bne	2b



	/*

	 * The SHA functions are:

	 *

	 * f1(B,C,D) = (D ^ (B & (C ^ D)))

	 * f2(B,C,D) = (B ^ C ^ D)

	 * f3(B,C,D) = ((B & C) | (D & (B | C)))

	 *

	 * Then the sub-blocks are processed as follows:

	 *

	 * A' = ror(A, 27) + f(B,C,D) + E + K + *W++

	 * B' = A

	 * C' = ror(B, 2)

	 * D' = C

	 * E' = D

	 *

	 * We therefore unroll each loop 5 times to avoid register shuffling.

	 * Also the ror for C (and also D and E which are successivelyderived

	 * from it) is applied in place to cut on an additional mov insn for

	 * each round.

	 */



	.macro	sha_f1, A, B, C, D, E

	ldr	r3, [r2], #4

	eor	ip, \C, \D

	add	\E, r1, \E, ror #2

	and	ip, \B, ip, ror #2

	add	\E, \E, \A, ror #27

	eor	ip, ip, \D, ror #2

	add	\E, \E, r3

	add	\E, \E, ip

	.endm



	.macro	sha_f2, A, B, C, D, E

	ldr	r3, [r2], #4

	add	\E, r1, \E, ror #2

	eor	ip, \B, \C, ror #2

	add	\E, \E, \A, ror #27

	eor	ip, ip, \D, ror #2

	add	\E, \E, r3

	add	\E, \E, ip

	.endm



	.macro	sha_f3, A, B, C, D, E

	ldr	r3, [r2], #4

	add	\E, r1, \E, ror #2

	orr	ip, \B, \C, ror #2

	add	\E, \E, \A, ror #27

	and	ip, ip, \D, ror #2

	add	\E, \E, r3

	and	r3, \B, \C, ror #2

	orr	ip, ip, r3

	add	\E, \E, ip

	.endm



	ldmia	r0, {r4 - r8}



	mov	lr, #4

	ldr	r1, .L_sha_K + 0



	/* adjust initial values */

	mov	r6, r6, ror #30

	mov	r7, r7, ror #30

	mov	r8, r8, ror #30



3:	subs	lr, lr, #1

	sha_f1	r4, r5, r6, r7, r8

	sha_f1	r8, r4, r5, r6, r7

	sha_f1	r7, r8, r4, r5, r6

	sha_f1	r6, r7, r8, r4, r5

	sha_f1	r5, r6, r7, r8, r4

	bne	3b



	ldr	r1, .L_sha_K + 4

	mov	lr, #4



4:	subs	lr, lr, #1

	sha_f2	r4, r5, r6, r7, r8

	sha_f2	r8, r4, r5, r6, r7

	sha_f2	r7, r8, r4, r5, r6

	sha_f2	r6, r7, r8, r4, r5

	sha_f2	r5, r6, r7, r8, r4

	bne	4b



	ldr	r1, .L_sha_K + 8

	mov	lr, #4



5:	subs	lr, lr, #1

	sha_f3	r4, r5, r6, r7, r8

	sha_f3	r8, r4, r5, r6, r7

	sha_f3	r7, r8, r4, r5, r6

	sha_f3	r6, r7, r8, r4, r5

	sha_f3	r5, r6, r7, r8, r4

	bne	5b



	ldr	r1, .L_sha_K + 12

	mov	lr, #4



6:	subs	lr, lr, #1

	sha_f2	r4, r5, r6, r7, r8

	sha_f2	r8, r4, r5, r6, r7

	sha_f2	r7, r8, r4, r5, r6

	sha_f2	r6, r7, r8, r4, r5

	sha_f2	r5, r6, r7, r8, r4

	bne	6b



	ldmia	r0, {r1, r2, r3, ip, lr}

	add	r4, r1, r4

	add	r5, r2, r5

	add	r6, r3, r6, ror #2

	add	r7, ip, r7, ror #2

	add	r8, lr, r8, ror #2

	stmia	r0, {r4 - r8}



	ldmfd	sp!, {r4 - r8, pc}



ENDPROC(sha_transform)



	.align	2

.L_sha_K:

	.word	0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6





/*

 * void sha_init(__u32 *buf)

 */



	.align	2

.L_sha_initial_digest:

	.word	0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476, 0xc3d2e1f0



ENTRY(sha_init)



	str	lr, [sp, #-4]!

	adr	r1, .L_sha_initial_digest

	ldmia	r1, {r1, r2, r3, ip, lr}

	stmia	r0, {r1, r2, r3, ip, lr}

	ldr	pc, [sp], #4



ENDPROC(sha_init)

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