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author | Sebastian Andrzej Siewior <sebastian@breakpoint.cc> | 2009-07-03 12:09:41 +0800 |
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committer | Herbert Xu <herbert@gondor.apana.org.au> | 2009-07-03 12:09:41 +0800 |
commit | ed94070058033a3c99fe62c90d00c39dc443c679 (patch) | |
tree | 5ae19b435f0903e67834e10ddccec2be4cfa4ab6 /crypto/ansi_cprng.c | |
parent | a68f6610d4f1ebe61818f5926fa8fa9e75d06a95 (diff) | |
download | linux-stable-ed94070058033a3c99fe62c90d00c39dc443c679.tar.gz linux-stable-ed94070058033a3c99fe62c90d00c39dc443c679.tar.bz2 linux-stable-ed94070058033a3c99fe62c90d00c39dc443c679.zip |
crypto: ansi_prng - Use just a BH lock
The current code uses a mix of sping_lock() & spin_lock_irqsave(). This can
lead to deadlock with the correct timming & cprng_get_random() + cprng_reset()
sequence.
I've converted them to bottom half locks since all three user grab just a BH
lock so this runs probably in softirq :)
Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/ansi_cprng.c')
-rw-r--r-- | crypto/ansi_cprng.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/crypto/ansi_cprng.c b/crypto/ansi_cprng.c index d80ed4c1e009..ff00b58c2cdc 100644 --- a/crypto/ansi_cprng.c +++ b/crypto/ansi_cprng.c @@ -187,7 +187,6 @@ static int _get_more_prng_bytes(struct prng_context *ctx) /* Our exported functions */ static int get_prng_bytes(char *buf, size_t nbytes, struct prng_context *ctx) { - unsigned long flags; unsigned char *ptr = buf; unsigned int byte_count = (unsigned int)nbytes; int err; @@ -196,7 +195,7 @@ static int get_prng_bytes(char *buf, size_t nbytes, struct prng_context *ctx) if (nbytes < 0) return -EINVAL; - spin_lock_irqsave(&ctx->prng_lock, flags); + spin_lock_bh(&ctx->prng_lock); err = -EINVAL; if (ctx->flags & PRNG_NEED_RESET) @@ -268,7 +267,7 @@ empty_rbuf: goto remainder; done: - spin_unlock_irqrestore(&ctx->prng_lock, flags); + spin_unlock_bh(&ctx->prng_lock); dbgprint(KERN_CRIT "returning %d from get_prng_bytes in context %p\n", err, ctx); return err; @@ -287,7 +286,7 @@ static int reset_prng_context(struct prng_context *ctx, int rc = -EINVAL; unsigned char *prng_key; - spin_lock(&ctx->prng_lock); + spin_lock_bh(&ctx->prng_lock); ctx->flags |= PRNG_NEED_RESET; prng_key = (key != NULL) ? key : (unsigned char *)DEFAULT_PRNG_KEY; @@ -332,7 +331,7 @@ static int reset_prng_context(struct prng_context *ctx, rc = 0; ctx->flags &= ~PRNG_NEED_RESET; out: - spin_unlock(&ctx->prng_lock); + spin_unlock_bh(&ctx->prng_lock); return rc; |