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sched/preempt, powerpc: Disable preemption in enable_kernel_altivec()…
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… explicitly

enable_kernel_altivec() has to be called with disabled preemption.
Let's make this explicit, to prepare for pagefault_disable() not
touching preemption anymore.

Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: airlied@linux.ie
Cc: akpm@linux-foundation.org
Cc: bigeasy@linutronix.de
Cc: borntraeger@de.ibm.com
Cc: daniel.vetter@intel.com
Cc: heiko.carstens@de.ibm.com
Cc: herbert@gondor.apana.org.au
Cc: hocko@suse.cz
Cc: hughd@google.com
Cc: mst@redhat.com
Cc: paulus@samba.org
Cc: ralf@linux-mips.org
Cc: schwidefsky@de.ibm.com
Cc: yang.shi@windriver.com
Link: http://lkml.kernel.org/r/1431359540-32227-14-git-send-email-dahi@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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David Hildenbrand authored and Ingo Molnar committed May 19, 2015
1 parent 2f09b22 commit 5f76eea
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Showing 4 changed files with 27 additions and 6 deletions.
11 changes: 6 additions & 5 deletions arch/powerpc/lib/vmx-helper.c
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Original file line number Diff line number Diff line change
Expand Up @@ -27,11 +27,11 @@ int enter_vmx_usercopy(void)
if (in_interrupt())
return 0;

/* This acts as preempt_disable() as well and will make
* enable_kernel_altivec(). We need to disable page faults
* as they can call schedule and thus make us lose the VMX
* context. So on page faults, we just fail which will cause
* a fallback to the normal non-vmx copy.
preempt_disable();
/*
* We need to disable page faults as they can call schedule and
* thus make us lose the VMX context. So on page faults, we just
* fail which will cause a fallback to the normal non-vmx copy.
*/
pagefault_disable();

Expand All @@ -47,6 +47,7 @@ int enter_vmx_usercopy(void)
int exit_vmx_usercopy(void)
{
pagefault_enable();
preempt_enable();
return 0;
}

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8 changes: 7 additions & 1 deletion drivers/crypto/vmx/aes.c
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Original file line number Diff line number Diff line change
Expand Up @@ -78,12 +78,14 @@ static int p8_aes_setkey(struct crypto_tfm *tfm, const u8 *key,
int ret;
struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);

preempt_disable();
pagefault_disable();
enable_kernel_altivec();
ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
pagefault_enable();

preempt_enable();

ret += crypto_cipher_setkey(ctx->fallback, key, keylen);
return ret;
}
Expand All @@ -95,10 +97,12 @@ static void p8_aes_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
if (in_interrupt()) {
crypto_cipher_encrypt_one(ctx->fallback, dst, src);
} else {
preempt_disable();
pagefault_disable();
enable_kernel_altivec();
aes_p8_encrypt(src, dst, &ctx->enc_key);
pagefault_enable();
preempt_enable();
}
}

Expand All @@ -109,10 +113,12 @@ static void p8_aes_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
if (in_interrupt()) {
crypto_cipher_decrypt_one(ctx->fallback, dst, src);
} else {
preempt_disable();
pagefault_disable();
enable_kernel_altivec();
aes_p8_decrypt(src, dst, &ctx->dec_key);
pagefault_enable();
preempt_enable();
}
}

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6 changes: 6 additions & 0 deletions drivers/crypto/vmx/aes_cbc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -79,11 +79,13 @@ static int p8_aes_cbc_setkey(struct crypto_tfm *tfm, const u8 *key,
int ret;
struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);

preempt_disable();
pagefault_disable();
enable_kernel_altivec();
ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
pagefault_enable();
preempt_enable();

ret += crypto_blkcipher_setkey(ctx->fallback, key, keylen);
return ret;
Expand All @@ -106,6 +108,7 @@ static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
if (in_interrupt()) {
ret = crypto_blkcipher_encrypt(&fallback_desc, dst, src, nbytes);
} else {
preempt_disable();
pagefault_disable();
enable_kernel_altivec();

Expand All @@ -119,6 +122,7 @@ static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
}

pagefault_enable();
preempt_enable();
}

return ret;
Expand All @@ -141,6 +145,7 @@ static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
if (in_interrupt()) {
ret = crypto_blkcipher_decrypt(&fallback_desc, dst, src, nbytes);
} else {
preempt_disable();
pagefault_disable();
enable_kernel_altivec();

Expand All @@ -154,6 +159,7 @@ static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
}

pagefault_enable();
preempt_enable();
}

return ret;
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8 changes: 8 additions & 0 deletions drivers/crypto/vmx/ghash.c
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Original file line number Diff line number Diff line change
Expand Up @@ -114,11 +114,13 @@ static int p8_ghash_setkey(struct crypto_shash *tfm, const u8 *key,
if (keylen != GHASH_KEY_LEN)
return -EINVAL;

preempt_disable();
pagefault_disable();
enable_kernel_altivec();
enable_kernel_fp();
gcm_init_p8(ctx->htable, (const u64 *) key);
pagefault_enable();
preempt_enable();
return crypto_shash_setkey(ctx->fallback, key, keylen);
}

Expand All @@ -140,23 +142,27 @@ static int p8_ghash_update(struct shash_desc *desc,
}
memcpy(dctx->buffer + dctx->bytes, src,
GHASH_DIGEST_SIZE - dctx->bytes);
preempt_disable();
pagefault_disable();
enable_kernel_altivec();
enable_kernel_fp();
gcm_ghash_p8(dctx->shash, ctx->htable, dctx->buffer,
GHASH_DIGEST_SIZE);
pagefault_enable();
preempt_enable();
src += GHASH_DIGEST_SIZE - dctx->bytes;
srclen -= GHASH_DIGEST_SIZE - dctx->bytes;
dctx->bytes = 0;
}
len = srclen & ~(GHASH_DIGEST_SIZE - 1);
if (len) {
preempt_disable();
pagefault_disable();
enable_kernel_altivec();
enable_kernel_fp();
gcm_ghash_p8(dctx->shash, ctx->htable, src, len);
pagefault_enable();
preempt_enable();
src += len;
srclen -= len;
}
Expand All @@ -180,12 +186,14 @@ static int p8_ghash_final(struct shash_desc *desc, u8 *out)
if (dctx->bytes) {
for (i = dctx->bytes; i < GHASH_DIGEST_SIZE; i++)
dctx->buffer[i] = 0;
preempt_disable();
pagefault_disable();
enable_kernel_altivec();
enable_kernel_fp();
gcm_ghash_p8(dctx->shash, ctx->htable, dctx->buffer,
GHASH_DIGEST_SIZE);
pagefault_enable();
preempt_enable();
dctx->bytes = 0;
}
memcpy(out, dctx->shash, GHASH_DIGEST_SIZE);
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