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Commit e183914a authored by Denys Vlasenko's avatar Denys Vlasenko Committed by Herbert Xu
Browse files

crypto: x86 - make constants readonly, allow linker to merge them 



A lot of asm-optimized routines in arch/x86/crypto/ keep its
constants in .data. This is wrong, they should be on .rodata.

Mnay of these constants are the same in different modules.
For example, 128-bit shuffle mask 0x000102030405060708090A0B0C0D0E0F
exists in at least half a dozen places.

There is a way to let linker merge them and use just one copy.
The rules are as follows: mergeable objects of different sizes
should not share sections. You can't put them all in one .rodata
section, they will lose "mergeability".

GCC puts its mergeable constants in ".rodata.cstSIZE" sections,
or ".rodata.cstSIZE.<object_name>" if -fdata-sections is used.
This patch does the same:

	.section .rodata.cst16.SHUF_MASK, "aM", @progbits, 16

It is important that all data in such section consists of
16-byte elements, not larger ones, and there are no implicit
use of one element from another.

When this is not the case, use non-mergeable section:

	.section .rodata[.VAR_NAME], "a", @progbits

This reduces .data by ~15 kbytes:

    text    data     bss     dec      hex filename
11097415 2705840 2630712 16433967  fac32f vmlinux-prev.o
11112095 2690672 2630712 16433479  fac147 vmlinux.o

Merged objects are visible in System.map:

ffffffff81a28810 r POLY
ffffffff81a28810 r POLY
ffffffff81a28820 r TWOONE
ffffffff81a28820 r TWOONE
ffffffff81a28830 r PSHUFFLE_BYTE_FLIP_MASK <- merged regardless of
ffffffff81a28830 r SHUF_MASK   <------------- the name difference
ffffffff81a28830 r SHUF_MASK
ffffffff81a28830 r SHUF_MASK
..
ffffffff81a28d00 r K512 <- merged three identical 640-byte tables
ffffffff81a28d00 r K512
ffffffff81a28d00 r K512

Use of object names in section name suffixes is not strictly necessary,
but might help if someday link stage will use garbage collection
to eliminate unused sections (ld --gc-sections).

Signed-off-by: default avatarDenys Vlasenko <dvlasenk@redhat.com>
CC: Herbert Xu <herbert@gondor.apana.org.au>
CC: Josh Poimboeuf <jpoimboe@redhat.com>
CC: Xiaodong Liu <xiaodong.liu@intel.com>
CC: Megha Dey <megha.dey@intel.com>
CC: linux-crypto@vger.kernel.org
CC: x86@kernel.org
CC: linux-kernel@vger.kernel.org
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 587d531b

arch/x86/crypto/aesni-intel_asm.S

+29 −8
Original line number Diff line number Diff line
@@ -46,28 +46,49 @@ 


#ifdef __x86_64__



.data

# constants in mergeable sections, linker can reorder and merge

.section	.rodata.cst16.gf128mul_x_ble_mask, "aM", @progbits, 16

.align 16

.Lgf128mul_x_ble_mask:

	.octa 0x00000000000000010000000000000087

.section	.rodata.cst16.POLY, "aM", @progbits, 16

.align 16

POLY:   .octa 0xC2000000000000000000000000000001

.section	.rodata.cst16.TWOONE, "aM", @progbits, 16

.align 16

TWOONE: .octa 0x00000001000000000000000000000001



# order of these constants should not change.

# more specifically, ALL_F should follow SHIFT_MASK,

# and ZERO should follow ALL_F



.section	.rodata.cst16.SHUF_MASK, "aM", @progbits, 16

.align 16

SHUF_MASK:  .octa 0x000102030405060708090A0B0C0D0E0F

.section	.rodata.cst16.MASK1, "aM", @progbits, 16

.align 16

MASK1:      .octa 0x0000000000000000ffffffffffffffff

.section	.rodata.cst16.MASK2, "aM", @progbits, 16

.align 16

MASK2:      .octa 0xffffffffffffffff0000000000000000

SHIFT_MASK: .octa 0x0f0e0d0c0b0a09080706050403020100

ALL_F:      .octa 0xffffffffffffffffffffffffffffffff

ZERO:       .octa 0x00000000000000000000000000000000

.section	.rodata.cst16.ONE, "aM", @progbits, 16

.align 16

ONE:        .octa 0x00000000000000000000000000000001

.section	.rodata.cst16.F_MIN_MASK, "aM", @progbits, 16

.align 16

F_MIN_MASK: .octa 0xf1f2f3f4f5f6f7f8f9fafbfcfdfeff0

.section	.rodata.cst16.dec, "aM", @progbits, 16

.align 16

dec:        .octa 0x1

.section	.rodata.cst16.enc, "aM", @progbits, 16

.align 16

enc:        .octa 0x2



# order of these constants should not change.

# more specifically, ALL_F should follow SHIFT_MASK,

# and zero should follow ALL_F

.section	.rodata, "a", @progbits

.align 16

SHIFT_MASK: .octa 0x0f0e0d0c0b0a09080706050403020100

ALL_F:      .octa 0xffffffffffffffffffffffffffffffff

            .octa 0x00000000000000000000000000000000





.text

arch/x86/crypto/aesni-intel_avx-x86_64.S

+24 −8
Original line number Diff line number Diff line
@@ -122,23 +122,39 @@ 
#include <linux/linkage.h>

#include <asm/inst.h>



.data

# constants in mergeable sections, linker can reorder and merge

.section	.rodata.cst16.POLY, "aM", @progbits, 16

.align 16



POLY:            .octa     0xC2000000000000000000000000000001



.section	.rodata.cst16.POLY2, "aM", @progbits, 16

.align 16

POLY2:           .octa     0xC20000000000000000000001C2000000

TWOONE:          .octa     0x00000001000000000000000000000001



# order of these constants should not change.

# more specifically, ALL_F should follow SHIFT_MASK, and ZERO should follow ALL_F

.section	.rodata.cst16.TWOONE, "aM", @progbits, 16

.align 16

TWOONE:          .octa     0x00000001000000000000000000000001



.section	.rodata.cst16.SHUF_MASK, "aM", @progbits, 16

.align 16

SHUF_MASK:       .octa     0x000102030405060708090A0B0C0D0E0F

SHIFT_MASK:      .octa     0x0f0e0d0c0b0a09080706050403020100

ALL_F:           .octa     0xffffffffffffffffffffffffffffffff

ZERO:            .octa     0x00000000000000000000000000000000



.section	.rodata.cst16.ONE, "aM", @progbits, 16

.align 16

ONE:             .octa     0x00000000000000000000000000000001



.section	.rodata.cst16.ONEf, "aM", @progbits, 16

.align 16

ONEf:            .octa     0x01000000000000000000000000000000



# order of these constants should not change.

# more specifically, ALL_F should follow SHIFT_MASK, and zero should follow ALL_F

.section	.rodata, "a", @progbits

.align 16

SHIFT_MASK:      .octa     0x0f0e0d0c0b0a09080706050403020100

ALL_F:           .octa     0xffffffffffffffffffffffffffffffff

                 .octa     0x00000000000000000000000000000000



.text

arch/x86/crypto/camellia-aesni-avx-asm_64.S

+4 −1
Original line number Diff line number Diff line
@@ -571,7 +571,9 @@ ENDPROC(roundsm16_x4_x5_x6_x7_x0_x1_x2_x3_y4_y5_y6_y7_y0_y1_y2_y3_ab) 
	vmovdqu y6, 14 * 16(rio); \

	vmovdqu y7, 15 * 16(rio);



.data



/* NB: section is mergeable, all elements must be aligned 16-byte blocks */

.section	.rodata.cst16, "aM", @progbits, 16

.align 16



#define SHUFB_BYTES(idx) \
@@ -711,6 +713,7 @@ ENDPROC(roundsm16_x4_x5_x6_x7_x0_x1_x2_x3_y4_y5_y6_y7_y0_y1_y2_y3_ab) 
	.byte 0x08, 0x05, 0x02, 0x0f, 0x0c, 0x09, 0x06, 0x03



/* 4-bit mask */

.section	.rodata.cst4.L0f0f0f0f, "aM", @progbits, 4

.align 4

.L0f0f0f0f:

	.long 0x0f0f0f0f

arch/x86/crypto/camellia-aesni-avx2-asm_64.S

+9 −3
Original line number Diff line number Diff line
@@ -610,20 +610,25 @@ ENDPROC(roundsm32_x4_x5_x6_x7_x0_x1_x2_x3_y4_y5_y6_y7_y0_y1_y2_y3_ab) 
	vmovdqu y6, 14 * 32(rio); \

	vmovdqu y7, 15 * 32(rio);



.data

.align 32



.section	.rodata.cst32.shufb_16x16b, "aM", @progbits, 32

.align 32

#define SHUFB_BYTES(idx) \

	0 + (idx), 4 + (idx), 8 + (idx), 12 + (idx)



.Lshufb_16x16b:

	.byte SHUFB_BYTES(0), SHUFB_BYTES(1), SHUFB_BYTES(2), SHUFB_BYTES(3)

	.byte SHUFB_BYTES(0), SHUFB_BYTES(1), SHUFB_BYTES(2), SHUFB_BYTES(3)



.section	.rodata.cst32.pack_bswap, "aM", @progbits, 32

.align 32

.Lpack_bswap:

	.long 0x00010203, 0x04050607, 0x80808080, 0x80808080

	.long 0x00010203, 0x04050607, 0x80808080, 0x80808080



/* NB: section is mergeable, all elements must be aligned 16-byte blocks */

.section	.rodata.cst16, "aM", @progbits, 16

.align 16



/* For CTR-mode IV byteswap */

.Lbswap128_mask:

	.byte 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0
@@ -750,6 +755,7 @@ ENDPROC(roundsm32_x4_x5_x6_x7_x0_x1_x2_x3_y4_y5_y6_y7_y0_y1_y2_y3_ab) 
	.byte 0x00, 0x0d, 0x0a, 0x07, 0x04, 0x01, 0x0e, 0x0b

	.byte 0x08, 0x05, 0x02, 0x0f, 0x0c, 0x09, 0x06, 0x03



.section	.rodata.cst4.L0f0f0f0f, "aM", @progbits, 4

.align 4

/* 4-bit mask */

.L0f0f0f0f:

arch/x86/crypto/cast5-avx-x86_64-asm_64.S

+12 −2
Original line number Diff line number Diff line
@@ -195,19 +195,29 @@ 
	vpshufb rmask,	x0, x0;           \

	vpshufb rmask,	x1, x1;



.data



.section	.rodata.cst16.bswap_mask, "aM", @progbits, 16

.align 16

.Lbswap_mask:

	.byte 3, 2, 1, 0, 7, 6, 5, 4, 11, 10, 9, 8, 15, 14, 13, 12

.section	.rodata.cst16.bswap128_mask, "aM", @progbits, 16

.align 16

.Lbswap128_mask:

	.byte 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0

.section	.rodata.cst16.bswap_iv_mask, "aM", @progbits, 16

.align 16

.Lbswap_iv_mask:

	.byte 7, 6, 5, 4, 3, 2, 1, 0, 7, 6, 5, 4, 3, 2, 1, 0



.section	.rodata.cst4.16_mask, "aM", @progbits, 4

.align 4

.L16_mask:

	.byte 16, 16, 16, 16

.section	.rodata.cst4.32_mask, "aM", @progbits, 4

.align 4

.L32_mask:

	.byte 32, 0, 0, 0

.section	.rodata.cst4.first_mask, "aM", @progbits, 4

.align 4

.Lfirst_mask:

	.byte 0x1f, 0, 0, 0