[patch] crypto, tcrypt: remove local_bh_disable/enable() aroundlocal_irq_disable/enable()

From: Suresh Siddha
Date: Mon Sep 17 2012 - 13:37:58 EST


Ran into this while looking at some new crypto code using FPU
hitting a WARN_ON_ONCE(!irq_fpu_usable()) in the kernel_fpu_begin()
on a x86 kernel that uses the new eagerfpu model. In short, current eagerfpu
changes return 0 for interrupted_kernel_fpu_idle() and the in_interrupt()
thinks it is in the interrupt context because of the local_bh_disable().
Thus resulting in the WARN_ON().

Remove the local_bh_disable/enable() calls around the existing
local_irq_disable/enable() calls. local_irq_disable/enable() already
disables the BH.

[ If there are any other legitimate users calling kernel_fpu_begin() from
the process context but with BH disabled, then we can look into fixing the
irq_fpu_usable() in future. ]

Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Cc: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>
---
crypto/tcrypt.c | 6 ------
1 files changed, 0 insertions(+), 6 deletions(-)

diff --git a/crypto/tcrypt.c b/crypto/tcrypt.c
index 5cf2ccb..de8c5d3 100644
--- a/crypto/tcrypt.c
+++ b/crypto/tcrypt.c
@@ -97,7 +97,6 @@ static int test_cipher_cycles(struct blkcipher_desc *desc, int enc,
int ret = 0;
int i;

- local_bh_disable();
local_irq_disable();

/* Warm-up run. */
@@ -130,7 +129,6 @@ static int test_cipher_cycles(struct blkcipher_desc *desc, int enc,

out:
local_irq_enable();
- local_bh_enable();

if (ret == 0)
printk("1 operation in %lu cycles (%d bytes)\n",
@@ -300,7 +298,6 @@ static int test_hash_cycles_digest(struct hash_desc *desc,
int i;
int ret;

- local_bh_disable();
local_irq_disable();

/* Warm-up run. */
@@ -327,7 +324,6 @@ static int test_hash_cycles_digest(struct hash_desc *desc,

out:
local_irq_enable();
- local_bh_enable();

if (ret)
return ret;
@@ -348,7 +344,6 @@ static int test_hash_cycles(struct hash_desc *desc, struct scatterlist *sg,
if (plen == blen)
return test_hash_cycles_digest(desc, sg, blen, out);

- local_bh_disable();
local_irq_disable();

/* Warm-up run. */
@@ -391,7 +386,6 @@ static int test_hash_cycles(struct hash_desc *desc, struct scatterlist *sg,

out:
local_irq_enable();
- local_bh_enable();

if (ret)
return ret;


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