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Date: Tue, 1 Nov 2016 00:14:49 -0700
From: tip-bot for Andy Lutomirski <tipbot@...or.com>
To: linux-tip-commits@...r.kernel.org
Cc: mingo@...nel.org, kvm@...r.kernel.org,
torvalds@...ux-foundation.org, linux-kernel@...r.kernel.org,
luto@...nel.org, brgerst@...il.com, rusty@...tcorp.com.au,
fenghua.yu@...el.com, pbonzini@...hat.com, oleg@...hat.com,
dvlasenk@...hat.com, peterz@...radead.org, riel@...hat.com,
bp@...en8.de, tglx@...utronix.de, dave.hansen@...ux.intel.com,
quentin.casasnovas@...cle.com, jpoimboe@...hat.com, hpa@...or.com
Subject: [tip:x86/fpu] x86/fpu: Remove irq_ts_save() and irq_ts_restore()
Commit-ID: 5a83d60c074ddf4f6364be25654a643d0e941824
Gitweb: http://git.kernel.org/tip/5a83d60c074ddf4f6364be25654a643d0e941824
Author: Andy Lutomirski <luto@...nel.org>
AuthorDate: Mon, 31 Oct 2016 15:18:44 -0700
Committer: Ingo Molnar <mingo@...nel.org>
CommitDate: Tue, 1 Nov 2016 07:47:54 +0100
x86/fpu: Remove irq_ts_save() and irq_ts_restore()
Now that lazy FPU is gone, we don't use CR0.TS (except possibly in
KVM guest mode). Remove irq_ts_save(), irq_ts_restore(), and all of
their callers.
Signed-off-by: Andy Lutomirski <luto@...nel.org>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Brian Gerst <brgerst@...il.com>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: Denys Vlasenko <dvlasenk@...hat.com>
Cc: Fenghua Yu <fenghua.yu@...el.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Josh Poimboeuf <jpoimboe@...hat.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Oleg Nesterov <oleg@...hat.com>
Cc: Paolo Bonzini <pbonzini@...hat.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@...cle.com>
Cc: Rik van Riel <riel@...hat.com>
Cc: Rusty Russell <rusty@...tcorp.com.au>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: kvm list <kvm@...r.kernel.org>
Link: http://lkml.kernel.org/r/70b9b9e7ba70659bedcb08aba63d0f9214f338f2.1477951965.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
arch/x86/include/asm/fpu/api.h | 10 ----------
arch/x86/kernel/fpu/core.c | 29 -----------------------------
drivers/char/hw_random/via-rng.c | 8 ++------
drivers/crypto/padlock-aes.c | 23 ++---------------------
drivers/crypto/padlock-sha.c | 18 ------------------
5 files changed, 4 insertions(+), 84 deletions(-)
diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h
index 1429a7c..0877ae0 100644
--- a/arch/x86/include/asm/fpu/api.h
+++ b/arch/x86/include/asm/fpu/api.h
@@ -27,16 +27,6 @@ extern void kernel_fpu_end(void);
extern bool irq_fpu_usable(void);
/*
- * Some instructions like VIA's padlock instructions generate a spurious
- * DNA fault but don't modify SSE registers. And these instructions
- * get used from interrupt context as well. To prevent these kernel instructions
- * in interrupt context interacting wrongly with other user/kernel fpu usage, we
- * should use them only in the context of irq_ts_save/restore()
- */
-extern int irq_ts_save(void);
-extern void irq_ts_restore(int TS_state);
-
-/*
* Query the presence of one or more xfeatures. Works on any legacy CPU as well.
*
* If 'feature_name' is set then put a human-readable description of
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 52f56844..7d8e262 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -138,35 +138,6 @@ void kernel_fpu_end(void)
EXPORT_SYMBOL_GPL(kernel_fpu_end);
/*
- * CR0::TS save/restore functions:
- */
-int irq_ts_save(void)
-{
- /*
- * If in process context and not atomic, we can take a spurious DNA fault.
- * Otherwise, doing clts() in process context requires disabling preemption
- * or some heavy lifting like kernel_fpu_begin()
- */
- if (!in_atomic())
- return 0;
-
- if (read_cr0() & X86_CR0_TS) {
- clts();
- return 1;
- }
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(irq_ts_save);
-
-void irq_ts_restore(int TS_state)
-{
- if (TS_state)
- stts();
-}
-EXPORT_SYMBOL_GPL(irq_ts_restore);
-
-/*
* Save the FPU state (mark it for reload if necessary):
*
* This only ever gets called for the current task.
diff --git a/drivers/char/hw_random/via-rng.c b/drivers/char/hw_random/via-rng.c
index 44ce806..d1f5bb5 100644
--- a/drivers/char/hw_random/via-rng.c
+++ b/drivers/char/hw_random/via-rng.c
@@ -70,21 +70,17 @@ enum {
* until we have 4 bytes, thus returning a u32 at a time,
* instead of the current u8-at-a-time.
*
- * Padlock instructions can generate a spurious DNA fault, so
- * we have to call them in the context of irq_ts_save/restore()
+ * Padlock instructions can generate a spurious DNA fault, but the
+ * kernel doesn't use CR0.TS, so this doesn't matter.
*/
static inline u32 xstore(u32 *addr, u32 edx_in)
{
u32 eax_out;
- int ts_state;
-
- ts_state = irq_ts_save();
asm(".byte 0x0F,0xA7,0xC0 /* xstore %%edi (addr=%0) */"
: "=m" (*addr), "=a" (eax_out), "+d" (edx_in), "+D" (addr));
- irq_ts_restore(ts_state);
return eax_out;
}
diff --git a/drivers/crypto/padlock-aes.c b/drivers/crypto/padlock-aes.c
index 441e86b..b386974 100644
--- a/drivers/crypto/padlock-aes.c
+++ b/drivers/crypto/padlock-aes.c
@@ -183,8 +183,8 @@ static inline void padlock_store_cword(struct cword *cword)
/*
* While the padlock instructions don't use FP/SSE registers, they
- * generate a spurious DNA fault when cr0.ts is '1'. These instructions
- * should be used only inside the irq_ts_save/restore() context
+ * generate a spurious DNA fault when CR0.TS is '1'. Fortunately,
+ * the kernel doesn't use CR0.TS.
*/
static inline void rep_xcrypt_ecb(const u8 *input, u8 *output, void *key,
@@ -298,24 +298,18 @@ static inline u8 *padlock_xcrypt_cbc(const u8 *input, u8 *output, void *key,
static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
struct aes_ctx *ctx = aes_ctx(tfm);
- int ts_state;
padlock_reset_key(&ctx->cword.encrypt);
- ts_state = irq_ts_save();
ecb_crypt(in, out, ctx->E, &ctx->cword.encrypt, 1);
- irq_ts_restore(ts_state);
padlock_store_cword(&ctx->cword.encrypt);
}
static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
struct aes_ctx *ctx = aes_ctx(tfm);
- int ts_state;
padlock_reset_key(&ctx->cword.encrypt);
- ts_state = irq_ts_save();
ecb_crypt(in, out, ctx->D, &ctx->cword.decrypt, 1);
- irq_ts_restore(ts_state);
padlock_store_cword(&ctx->cword.encrypt);
}
@@ -346,14 +340,12 @@ static int ecb_aes_encrypt(struct blkcipher_desc *desc,
struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
struct blkcipher_walk walk;
int err;
- int ts_state;
padlock_reset_key(&ctx->cword.encrypt);
blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt(desc, &walk);
- ts_state = irq_ts_save();
while ((nbytes = walk.nbytes)) {
padlock_xcrypt_ecb(walk.src.virt.addr, walk.dst.virt.addr,
ctx->E, &ctx->cword.encrypt,
@@ -361,7 +353,6 @@ static int ecb_aes_encrypt(struct blkcipher_desc *desc,
nbytes &= AES_BLOCK_SIZE - 1;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
- irq_ts_restore(ts_state);
padlock_store_cword(&ctx->cword.encrypt);
@@ -375,14 +366,12 @@ static int ecb_aes_decrypt(struct blkcipher_desc *desc,
struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
struct blkcipher_walk walk;
int err;
- int ts_state;
padlock_reset_key(&ctx->cword.decrypt);
blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt(desc, &walk);
- ts_state = irq_ts_save();
while ((nbytes = walk.nbytes)) {
padlock_xcrypt_ecb(walk.src.virt.addr, walk.dst.virt.addr,
ctx->D, &ctx->cword.decrypt,
@@ -390,7 +379,6 @@ static int ecb_aes_decrypt(struct blkcipher_desc *desc,
nbytes &= AES_BLOCK_SIZE - 1;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
- irq_ts_restore(ts_state);
padlock_store_cword(&ctx->cword.encrypt);
@@ -425,14 +413,12 @@ static int cbc_aes_encrypt(struct blkcipher_desc *desc,
struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
struct blkcipher_walk walk;
int err;
- int ts_state;
padlock_reset_key(&ctx->cword.encrypt);
blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt(desc, &walk);
- ts_state = irq_ts_save();
while ((nbytes = walk.nbytes)) {
u8 *iv = padlock_xcrypt_cbc(walk.src.virt.addr,
walk.dst.virt.addr, ctx->E,
@@ -442,7 +428,6 @@ static int cbc_aes_encrypt(struct blkcipher_desc *desc,
nbytes &= AES_BLOCK_SIZE - 1;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
- irq_ts_restore(ts_state);
padlock_store_cword(&ctx->cword.decrypt);
@@ -456,14 +441,12 @@ static int cbc_aes_decrypt(struct blkcipher_desc *desc,
struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
struct blkcipher_walk walk;
int err;
- int ts_state;
padlock_reset_key(&ctx->cword.encrypt);
blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt(desc, &walk);
- ts_state = irq_ts_save();
while ((nbytes = walk.nbytes)) {
padlock_xcrypt_cbc(walk.src.virt.addr, walk.dst.virt.addr,
ctx->D, walk.iv, &ctx->cword.decrypt,
@@ -472,8 +455,6 @@ static int cbc_aes_decrypt(struct blkcipher_desc *desc,
err = blkcipher_walk_done(desc, &walk, nbytes);
}
- irq_ts_restore(ts_state);
-
padlock_store_cword(&ctx->cword.encrypt);
return err;
diff --git a/drivers/crypto/padlock-sha.c b/drivers/crypto/padlock-sha.c
index 8c5f906..bc72d20 100644
--- a/drivers/crypto/padlock-sha.c
+++ b/drivers/crypto/padlock-sha.c
@@ -89,7 +89,6 @@ static int padlock_sha1_finup(struct shash_desc *desc, const u8 *in,
struct sha1_state state;
unsigned int space;
unsigned int leftover;
- int ts_state;
int err;
dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
@@ -120,14 +119,11 @@ static int padlock_sha1_finup(struct shash_desc *desc, const u8 *in,
memcpy(result, &state.state, SHA1_DIGEST_SIZE);
- /* prevent taking the spurious DNA fault with padlock. */
- ts_state = irq_ts_save();
asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
: \
: "c"((unsigned long)state.count + count), \
"a"((unsigned long)state.count), \
"S"(in), "D"(result));
- irq_ts_restore(ts_state);
padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);
@@ -155,7 +151,6 @@ static int padlock_sha256_finup(struct shash_desc *desc, const u8 *in,
struct sha256_state state;
unsigned int space;
unsigned int leftover;
- int ts_state;
int err;
dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
@@ -186,14 +181,11 @@ static int padlock_sha256_finup(struct shash_desc *desc, const u8 *in,
memcpy(result, &state.state, SHA256_DIGEST_SIZE);
- /* prevent taking the spurious DNA fault with padlock. */
- ts_state = irq_ts_save();
asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
: \
: "c"((unsigned long)state.count + count), \
"a"((unsigned long)state.count), \
"S"(in), "D"(result));
- irq_ts_restore(ts_state);
padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);
@@ -312,7 +304,6 @@ static int padlock_sha1_update_nano(struct shash_desc *desc,
u8 buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
((aligned(STACK_ALIGN)));
u8 *dst = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
- int ts_state;
partial = sctx->count & 0x3f;
sctx->count += len;
@@ -328,23 +319,19 @@ static int padlock_sha1_update_nano(struct shash_desc *desc,
memcpy(sctx->buffer + partial, data,
done + SHA1_BLOCK_SIZE);
src = sctx->buffer;
- ts_state = irq_ts_save();
asm volatile (".byte 0xf3,0x0f,0xa6,0xc8"
: "+S"(src), "+D"(dst) \
: "a"((long)-1), "c"((unsigned long)1));
- irq_ts_restore(ts_state);
done += SHA1_BLOCK_SIZE;
src = data + done;
}
/* Process the left bytes from the input data */
if (len - done >= SHA1_BLOCK_SIZE) {
- ts_state = irq_ts_save();
asm volatile (".byte 0xf3,0x0f,0xa6,0xc8"
: "+S"(src), "+D"(dst)
: "a"((long)-1),
"c"((unsigned long)((len - done) / SHA1_BLOCK_SIZE)));
- irq_ts_restore(ts_state);
done += ((len - done) - (len - done) % SHA1_BLOCK_SIZE);
src = data + done;
}
@@ -401,7 +388,6 @@ static int padlock_sha256_update_nano(struct shash_desc *desc, const u8 *data,
u8 buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
((aligned(STACK_ALIGN)));
u8 *dst = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
- int ts_state;
partial = sctx->count & 0x3f;
sctx->count += len;
@@ -417,23 +403,19 @@ static int padlock_sha256_update_nano(struct shash_desc *desc, const u8 *data,
memcpy(sctx->buf + partial, data,
done + SHA256_BLOCK_SIZE);
src = sctx->buf;
- ts_state = irq_ts_save();
asm volatile (".byte 0xf3,0x0f,0xa6,0xd0"
: "+S"(src), "+D"(dst)
: "a"((long)-1), "c"((unsigned long)1));
- irq_ts_restore(ts_state);
done += SHA256_BLOCK_SIZE;
src = data + done;
}
/* Process the left bytes from input data*/
if (len - done >= SHA256_BLOCK_SIZE) {
- ts_state = irq_ts_save();
asm volatile (".byte 0xf3,0x0f,0xa6,0xd0"
: "+S"(src), "+D"(dst)
: "a"((long)-1),
"c"((unsigned long)((len - done) / 64)));
- irq_ts_restore(ts_state);
done += ((len - done) - (len - done) % 64);
src = data + done;
}
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