When kernel mode NEON was first introduced on arm64, the preserve and
restore of the userland NEON state was completely unoptimized, and
involved saving all registers on each call to kernel_neon_begin(),
and restoring them on each call to kernel_neon_end(). For this reason,
the NEON crypto code that was introduced at the time keeps the NEON
enabled throughout the execution of the crypto API methods, which may
include calls back into the crypto API that could result in memory
allocation or other actions that we should avoid when running with
preemption disabled.
Since then, we have optimized the kernel mode NEON handling, which now
restores lazily (upon return to userland), and so the preserve action
is only costly the first time it is called after entering the kernel.
So let's put the kernel_neon_begin() and kernel_neon_end() calls around
the actual invocations of the NEON crypto code, and run the remainder of
the code with kernel mode NEON disabled (and preemption enabled)
Note that this requires some reshuffling of the registers in the asm
code, because the XTS routines can no longer rely on the registers to
retain their contents between invocations.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
arch/arm64/crypto/aes-glue.c | 95 ++++++++++----------
arch/arm64/crypto/aes-modes.S | 90 +++++++++----------
arch/arm64/crypto/aes-neonbs-glue.c | 14 ++-
3 files changed, 97 insertions(+), 102 deletions(-)
diff --git a/arch/arm64/crypto/aes-glue.c b/arch/arm64/crypto/aes-glue.c
index 2fa850e86aa8..253188fb8cb0 100644
--- a/arch/arm64/crypto/aes-glue.c
+++ b/arch/arm64/crypto/aes-glue.c
@@ -64,17 +64,17 @@ MODULE_LICENSE("GPL v2");
/* defined in aes-modes.S */
asmlinkage void aes_ecb_encrypt(u8 out[], u8 const in[], u8 const rk[],
- int rounds, int blocks, int first);
+ int rounds, int blocks);
asmlinkage void aes_ecb_decrypt(u8 out[], u8 const in[], u8 const rk[],
- int rounds, int blocks, int first);
+ int rounds, int blocks);
asmlinkage void aes_cbc_encrypt(u8 out[], u8 const in[], u8 const rk[],
- int rounds, int blocks, u8 iv[], int first);
+ int rounds, int blocks, u8 iv[]);
asmlinkage void aes_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[],
- int rounds, int blocks, u8 iv[], int first);
+ int rounds, int blocks, u8 iv[]);
asmlinkage void aes_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[],
- int rounds, int blocks, u8 ctr[], int first);
+ int rounds, int blocks, u8 ctr[]);
asmlinkage void aes_xts_encrypt(u8 out[], u8 const in[], u8 const rk1[],
int rounds, int blocks, u8 const rk2[], u8 iv[],
@@ -133,19 +133,19 @@ static int ecb_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
- int err, first, rounds = 6 + ctx->key_length / 4;
+ int err, rounds = 6 + ctx->key_length / 4;
struct skcipher_walk walk;
unsigned int blocks;
- err = skcipher_walk_virt(&walk, req, true);
+ err = skcipher_walk_virt(&walk, req, false);
- kernel_neon_begin();
- for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) {
+ while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
+ kernel_neon_begin();
aes_ecb_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
- (u8 *)ctx->key_enc, rounds, blocks, first);
+ (u8 *)ctx->key_enc, rounds, blocks);
+ kernel_neon_end();
err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
}
- kernel_neon_end();
return err;
}
@@ -153,19 +153,19 @@ static int ecb_decrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
- int err, first, rounds = 6 + ctx->key_length / 4;
+ int err, rounds = 6 + ctx->key_length / 4;
struct skcipher_walk walk;
unsigned int blocks;
- err = skcipher_walk_virt(&walk, req, true);
+ err = skcipher_walk_virt(&walk, req, false);
- kernel_neon_begin();
- for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) {
+ while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
+ kernel_neon_begin();
aes_ecb_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
- (u8 *)ctx->key_dec, rounds, blocks, first);
+ (u8 *)ctx->key_dec, rounds, blocks);
+ kernel_neon_end();
err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
}
- kernel_neon_end();
return err;
}
@@ -173,20 +173,19 @@ static int cbc_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
- int err, first, rounds = 6 + ctx->key_length / 4;
+ int err, rounds = 6 + ctx->key_length / 4;
struct skcipher_walk walk;
unsigned int blocks;
- err = skcipher_walk_virt(&walk, req, true);
+ err = skcipher_walk_virt(&walk, req, false);
- kernel_neon_begin();
- for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) {
+ while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
+ kernel_neon_begin();
aes_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
- (u8 *)ctx->key_enc, rounds, blocks, walk.iv,
- first);
+ (u8 *)ctx->key_enc, rounds, blocks, walk.iv);
+ kernel_neon_end();
err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
}
- kernel_neon_end();
return err;
}
@@ -194,20 +193,19 @@ static int cbc_decrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
- int err, first, rounds = 6 + ctx->key_length / 4;
+ int err, rounds = 6 + ctx->key_length / 4;
struct skcipher_walk walk;
unsigned int blocks;
- err = skcipher_walk_virt(&walk, req, true);
+ err = skcipher_walk_virt(&walk, req, false);
- kernel_neon_begin();
- for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) {
+ while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
+ kernel_neon_begin();
aes_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
- (u8 *)ctx->key_dec, rounds, blocks, walk.iv,
- first);
+ (u8 *)ctx->key_dec, rounds, blocks, walk.iv);
+ kernel_neon_end();
err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
}
- kernel_neon_end();
return err;
}
@@ -215,20 +213,18 @@ static int ctr_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
- int err, first, rounds = 6 + ctx->key_length / 4;
+ int err, rounds = 6 + ctx->key_length / 4;
struct skcipher_walk walk;
int blocks;
- err = skcipher_walk_virt(&walk, req, true);
+ err = skcipher_walk_virt(&walk, req, false);
- first = 1;
- kernel_neon_begin();
while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
+ kernel_neon_begin();
aes_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
- (u8 *)ctx->key_enc, rounds, blocks, walk.iv,
- first);
+ (u8 *)ctx->key_enc, rounds, blocks, walk.iv);
err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
- first = 0;
+ kernel_neon_end();
}
if (walk.nbytes) {
u8 __aligned(8) tail[AES_BLOCK_SIZE];
@@ -241,12 +237,13 @@ static int ctr_encrypt(struct skcipher_request *req)
*/
blocks = -1;
+ kernel_neon_begin();
aes_ctr_encrypt(tail, NULL, (u8 *)ctx->key_enc, rounds,
- blocks, walk.iv, first);
+ blocks, walk.iv);
+ kernel_neon_end();
crypto_xor_cpy(tdst, tsrc, tail, nbytes);
err = skcipher_walk_done(&walk, 0);
}
- kernel_neon_end();
return err;
}
@@ -270,16 +267,16 @@ static int xts_encrypt(struct skcipher_request *req)
struct skcipher_walk walk;
unsigned int blocks;
- err = skcipher_walk_virt(&walk, req, true);
+ err = skcipher_walk_virt(&walk, req, false);
- kernel_neon_begin();
for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) {
+ kernel_neon_begin();
aes_xts_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
(u8 *)ctx->key1.key_enc, rounds, blocks,
(u8 *)ctx->key2.key_enc, walk.iv, first);
+ kernel_neon_end();
err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
}
- kernel_neon_end();
return err;
}
@@ -292,16 +289,16 @@ static int xts_decrypt(struct skcipher_request *req)
struct skcipher_walk walk;
unsigned int blocks;
- err = skcipher_walk_virt(&walk, req, true);
+ err = skcipher_walk_virt(&walk, req, false);
- kernel_neon_begin();
for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) {
+ kernel_neon_begin();
aes_xts_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
(u8 *)ctx->key1.key_dec, rounds, blocks,
(u8 *)ctx->key2.key_enc, walk.iv, first);
+ kernel_neon_end();
err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
}
- kernel_neon_end();
return err;
}
@@ -425,7 +422,7 @@ static int cmac_setkey(struct crypto_shash *tfm, const u8 *in_key,
/* encrypt the zero vector */
kernel_neon_begin();
- aes_ecb_encrypt(ctx->consts, (u8[AES_BLOCK_SIZE]){}, rk, rounds, 1, 1);
+ aes_ecb_encrypt(ctx->consts, (u8[AES_BLOCK_SIZE]){}, rk, rounds, 1);
kernel_neon_end();
cmac_gf128_mul_by_x(consts, consts);
@@ -454,8 +451,8 @@ static int xcbc_setkey(struct crypto_shash *tfm, const u8 *in_key,
return err;
kernel_neon_begin();
- aes_ecb_encrypt(key, ks[0], rk, rounds, 1, 1);
- aes_ecb_encrypt(ctx->consts, ks[1], rk, rounds, 2, 0);
+ aes_ecb_encrypt(key, ks[0], rk, rounds, 1);
+ aes_ecb_encrypt(ctx->consts, ks[1], rk, rounds, 2);
kernel_neon_end();
return cbcmac_setkey(tfm, key, sizeof(key));
diff --git a/arch/arm64/crypto/aes-modes.S b/arch/arm64/crypto/aes-modes.S
index 2674d43d1384..65b273667b34 100644
--- a/arch/arm64/crypto/aes-modes.S
+++ b/arch/arm64/crypto/aes-modes.S
@@ -40,24 +40,24 @@
#if INTERLEAVE == 2
aes_encrypt_block2x:
- encrypt_block2x v0, v1, w3, x2, x6, w7
+ encrypt_block2x v0, v1, w3, x2, x8, w7
ret
ENDPROC(aes_encrypt_block2x)
aes_decrypt_block2x:
- decrypt_block2x v0, v1, w3, x2, x6, w7
+ decrypt_block2x v0, v1, w3, x2, x8, w7
ret
ENDPROC(aes_decrypt_block2x)
#elif INTERLEAVE == 4
aes_encrypt_block4x:
- encrypt_block4x v0, v1, v2, v3, w3, x2, x6, w7
+ encrypt_block4x v0, v1, v2, v3, w3, x2, x8, w7
ret
ENDPROC(aes_encrypt_block4x)
aes_decrypt_block4x:
- decrypt_block4x v0, v1, v2, v3, w3, x2, x6, w7
+ decrypt_block4x v0, v1, v2, v3, w3, x2, x8, w7
ret
ENDPROC(aes_decrypt_block4x)
@@ -86,33 +86,32 @@ ENDPROC(aes_decrypt_block4x)
#define FRAME_POP
.macro do_encrypt_block2x
- encrypt_block2x v0, v1, w3, x2, x6, w7
+ encrypt_block2x v0, v1, w3, x2, x8, w7
.endm
.macro do_decrypt_block2x
- decrypt_block2x v0, v1, w3, x2, x6, w7
+ decrypt_block2x v0, v1, w3, x2, x8, w7
.endm
.macro do_encrypt_block4x
- encrypt_block4x v0, v1, v2, v3, w3, x2, x6, w7
+ encrypt_block4x v0, v1, v2, v3, w3, x2, x8, w7
.endm
.macro do_decrypt_block4x
- decrypt_block4x v0, v1, v2, v3, w3, x2, x6, w7
+ decrypt_block4x v0, v1, v2, v3, w3, x2, x8, w7
.endm
#endif
/*
* aes_ecb_encrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
- * int blocks, int first)
+ * int blocks)
* aes_ecb_decrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
- * int blocks, int first)
+ * int blocks)
*/
AES_ENTRY(aes_ecb_encrypt)
FRAME_PUSH
- cbz w5, .LecbencloopNx
enc_prepare w3, x2, x5
@@ -148,7 +147,6 @@ AES_ENDPROC(aes_ecb_encrypt)
AES_ENTRY(aes_ecb_decrypt)
FRAME_PUSH
- cbz w5, .LecbdecloopNx
dec_prepare w3, x2, x5
@@ -184,14 +182,12 @@ AES_ENDPROC(aes_ecb_decrypt)
/*
* aes_cbc_encrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
- * int blocks, u8 iv[], int first)
+ * int blocks, u8 iv[])
* aes_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
- * int blocks, u8 iv[], int first)
+ * int blocks, u8 iv[])
*/
AES_ENTRY(aes_cbc_encrypt)
- cbz w6, .Lcbcencloop
-
ld1 {v0.16b}, [x5] /* get iv */
enc_prepare w3, x2, x6
@@ -209,7 +205,6 @@ AES_ENDPROC(aes_cbc_encrypt)
AES_ENTRY(aes_cbc_decrypt)
FRAME_PUSH
- cbz w6, .LcbcdecloopNx
ld1 {v7.16b}, [x5] /* get iv */
dec_prepare w3, x2, x6
@@ -264,20 +259,19 @@ AES_ENDPROC(aes_cbc_decrypt)
/*
* aes_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
- * int blocks, u8 ctr[], int first)
+ * int blocks, u8 ctr[])
*/
AES_ENTRY(aes_ctr_encrypt)
FRAME_PUSH
- cbz w6, .Lctrnotfirst /* 1st time around? */
+
enc_prepare w3, x2, x6
ld1 {v4.16b}, [x5]
-.Lctrnotfirst:
- umov x8, v4.d[1] /* keep swabbed ctr in reg */
- rev x8, x8
+ umov x6, v4.d[1] /* keep swabbed ctr in reg */
+ rev x6, x6
#if INTERLEAVE >= 2
- cmn w8, w4 /* 32 bit overflow? */
+ cmn w6, w4 /* 32 bit overflow? */
bcs .Lctrloop
.LctrloopNx:
subs w4, w4, #INTERLEAVE
@@ -285,11 +279,11 @@ AES_ENTRY(aes_ctr_encrypt)
#if INTERLEAVE == 2
mov v0.8b, v4.8b
mov v1.8b, v4.8b
- rev x7, x8
- add x8, x8, #1
+ rev x7, x6
+ add x6, x6, #1
ins v0.d[1], x7
- rev x7, x8
- add x8, x8, #1
+ rev x7, x6
+ add x6, x6, #1
ins v1.d[1], x7
ld1 {v2.16b-v3.16b}, [x1], #32 /* get 2 input blocks */
do_encrypt_block2x
@@ -298,7 +292,7 @@ AES_ENTRY(aes_ctr_encrypt)
st1 {v0.16b-v1.16b}, [x0], #32
#else
ldr q8, =0x30000000200000001 /* addends 1,2,3[,0] */
- dup v7.4s, w8
+ dup v7.4s, w6
mov v0.16b, v4.16b
add v7.4s, v7.4s, v8.4s
mov v1.16b, v4.16b
@@ -316,9 +310,9 @@ AES_ENTRY(aes_ctr_encrypt)
eor v2.16b, v7.16b, v2.16b
eor v3.16b, v5.16b, v3.16b
st1 {v0.16b-v3.16b}, [x0], #64
- add x8, x8, #INTERLEAVE
+ add x6, x6, #INTERLEAVE
#endif
- rev x7, x8
+ rev x7, x6
ins v4.d[1], x7
cbz w4, .Lctrout
b .LctrloopNx
@@ -328,10 +322,10 @@ AES_ENTRY(aes_ctr_encrypt)
#endif
.Lctrloop:
mov v0.16b, v4.16b
- encrypt_block v0, w3, x2, x6, w7
+ encrypt_block v0, w3, x2, x8, w7
- adds x8, x8, #1 /* increment BE ctr */
- rev x7, x8
+ adds x6, x6, #1 /* increment BE ctr */
+ rev x7, x6
ins v4.d[1], x7
bcs .Lctrcarry /* overflow? */
@@ -385,15 +379,17 @@ CPU_BE( .quad 0x87, 1 )
AES_ENTRY(aes_xts_encrypt)
FRAME_PUSH
- cbz w7, .LxtsencloopNx
-
ld1 {v4.16b}, [x6]
- enc_prepare w3, x5, x6
- encrypt_block v4, w3, x5, x6, w7 /* first tweak */
- enc_switch_key w3, x2, x6
+ cbz w7, .Lxtsencnotfirst
+
+ enc_prepare w3, x5, x8
+ encrypt_block v4, w3, x5, x8, w7 /* first tweak */
+ enc_switch_key w3, x2, x8
ldr q7, .Lxts_mul_x
b .LxtsencNx
+.Lxtsencnotfirst:
+ enc_prepare w3, x2, x8
.LxtsencloopNx:
ldr q7, .Lxts_mul_x
next_tweak v4, v4, v7, v8
@@ -442,7 +438,7 @@ AES_ENTRY(aes_xts_encrypt)
.Lxtsencloop:
ld1 {v1.16b}, [x1], #16
eor v0.16b, v1.16b, v4.16b
- encrypt_block v0, w3, x2, x6, w7
+ encrypt_block v0, w3, x2, x8, w7
eor v0.16b, v0.16b, v4.16b
st1 {v0.16b}, [x0], #16
subs w4, w4, #1
@@ -450,6 +446,7 @@ AES_ENTRY(aes_xts_encrypt)
next_tweak v4, v4, v7, v8
b .Lxtsencloop
.Lxtsencout:
+ st1 {v4.16b}, [x6]
FRAME_POP
ret
AES_ENDPROC(aes_xts_encrypt)
@@ -457,15 +454,17 @@ AES_ENDPROC(aes_xts_encrypt)
AES_ENTRY(aes_xts_decrypt)
FRAME_PUSH
- cbz w7, .LxtsdecloopNx
-
ld1 {v4.16b}, [x6]
- enc_prepare w3, x5, x6
- encrypt_block v4, w3, x5, x6, w7 /* first tweak */
- dec_prepare w3, x2, x6
+ cbz w7, .Lxtsdecnotfirst
+
+ enc_prepare w3, x5, x8
+ encrypt_block v4, w3, x5, x8, w7 /* first tweak */
+ dec_prepare w3, x2, x8
ldr q7, .Lxts_mul_x
b .LxtsdecNx
+.Lxtsdecnotfirst:
+ dec_prepare w3, x2, x8
.LxtsdecloopNx:
ldr q7, .Lxts_mul_x
next_tweak v4, v4, v7, v8
@@ -514,7 +513,7 @@ AES_ENTRY(aes_xts_decrypt)
.Lxtsdecloop:
ld1 {v1.16b}, [x1], #16
eor v0.16b, v1.16b, v4.16b
- decrypt_block v0, w3, x2, x6, w7
+ decrypt_block v0, w3, x2, x8, w7
eor v0.16b, v0.16b, v4.16b
st1 {v0.16b}, [x0], #16
subs w4, w4, #1
@@ -522,6 +521,7 @@ AES_ENTRY(aes_xts_decrypt)
next_tweak v4, v4, v7, v8
b .Lxtsdecloop
.Lxtsdecout:
+ st1 {v4.16b}, [x6]
FRAME_POP
ret
AES_ENDPROC(aes_xts_decrypt)
diff --git a/arch/arm64/crypto/aes-neonbs-glue.c b/arch/arm64/crypto/aes-neonbs-glue.c
index c55d68ccb89f..9d823c77ec84 100644
--- a/arch/arm64/crypto/aes-neonbs-glue.c
+++ b/arch/arm64/crypto/aes-neonbs-glue.c
@@ -46,10 +46,9 @@ asmlinkage void aesbs_xts_decrypt(u8 out[], u8 const in[], u8 const rk[],
/* borrowed from aes-neon-blk.ko */
asmlinkage void neon_aes_ecb_encrypt(u8 out[], u8 const in[], u32 const rk[],
- int rounds, int blocks, int first);
+ int rounds, int blocks);
asmlinkage void neon_aes_cbc_encrypt(u8 out[], u8 const in[], u32 const rk[],
- int rounds, int blocks, u8 iv[],
- int first);
+ int rounds, int blocks, u8 iv[]);
struct aesbs_ctx {
u8 rk[13 * (8 * AES_BLOCK_SIZE) + 32];
@@ -157,7 +156,7 @@ static int cbc_encrypt(struct skcipher_request *req)
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
struct skcipher_walk walk;
- int err, first = 1;
+ int err;
err = skcipher_walk_virt(&walk, req, true);
@@ -167,10 +166,9 @@ static int cbc_encrypt(struct skcipher_request *req)
/* fall back to the non-bitsliced NEON implementation */
neon_aes_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
- ctx->enc, ctx->key.rounds, blocks, walk.iv,
- first);
+ ctx->enc, ctx->key.rounds, blocks,
+ walk.iv);
err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
- first = 0;
}
kernel_neon_end();
return err;
@@ -311,7 +309,7 @@ static int __xts_crypt(struct skcipher_request *req,
kernel_neon_begin();
neon_aes_ecb_encrypt(walk.iv, walk.iv, ctx->twkey,
- ctx->key.rounds, 1, 1);
+ ctx->key.rounds, 1);
while (walk.nbytes >= AES_BLOCK_SIZE) {
unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
--
2.15.1
