summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorPrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>2016-11-18 23:00:10 +0530
committerHerbert Xu <herbert@gondor.apana.org.au>2016-11-21 22:50:45 +0800
commited424bb3680b6e6167a44c5c195ec8f9aea3ab3b (patch)
tree11b446c82310aad649ff7888d479dbbdc5cd2a63
parent8ff4c191d1123ea1ba610dbc25e93568d9e7756c (diff)
hwrng: Make explicit that max >= 32 always
As hw_random core calls ->read with max > 32 or more, make it explicit. Also remove checks involving 'max' being less than 8. Signed-off-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
-rw-r--r--drivers/char/hw_random/msm-rng.c4
-rw-r--r--drivers/char/hw_random/pic32-rng.c3
-rw-r--r--drivers/char/hw_random/pseries-rng.c5
-rw-r--r--include/linux/hw_random.h3
4 files changed, 3 insertions, 12 deletions
diff --git a/drivers/char/hw_random/msm-rng.c b/drivers/char/hw_random/msm-rng.c
index 96fb986402eb..841fee845ec9 100644
--- a/drivers/char/hw_random/msm-rng.c
+++ b/drivers/char/hw_random/msm-rng.c
@@ -90,10 +90,6 @@ static int msm_rng_read(struct hwrng *hwrng, void *data, size_t max, bool wait)
/* calculate max size bytes to transfer back to caller */
maxsize = min_t(size_t, MAX_HW_FIFO_SIZE, max);
- /* no room for word data */
- if (maxsize < WORD_SZ)
- return 0;
-
ret = clk_prepare_enable(rng->clk);
if (ret)
return ret;
diff --git a/drivers/char/hw_random/pic32-rng.c b/drivers/char/hw_random/pic32-rng.c
index 11dc9b7c09ce..9b5e68a71d01 100644
--- a/drivers/char/hw_random/pic32-rng.c
+++ b/drivers/char/hw_random/pic32-rng.c
@@ -62,9 +62,6 @@ static int pic32_rng_read(struct hwrng *rng, void *buf, size_t max,
u32 t;
unsigned int timeout = RNG_TIMEOUT;
- if (max < 8)
- return 0;
-
do {
t = readl(priv->base + RNGRCNT) & RCNT_MASK;
if (t == 64) {
diff --git a/drivers/char/hw_random/pseries-rng.c b/drivers/char/hw_random/pseries-rng.c
index 63ce51d09af1..d9f46b437cc2 100644
--- a/drivers/char/hw_random/pseries-rng.c
+++ b/drivers/char/hw_random/pseries-rng.c
@@ -28,7 +28,6 @@
static int pseries_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
{
u64 buffer[PLPAR_HCALL_BUFSIZE];
- size_t size = max < 8 ? max : 8;
int rc;
rc = plpar_hcall(H_RANDOM, (unsigned long *)buffer);
@@ -36,10 +35,10 @@ static int pseries_rng_read(struct hwrng *rng, void *data, size_t max, bool wait
pr_err_ratelimited("H_RANDOM call failed %d\n", rc);
return -EIO;
}
- memcpy(data, buffer, size);
+ memcpy(data, buffer, 8);
/* The hypervisor interface returns 64 bits */
- return size;
+ return 8;
}
/**
diff --git a/include/linux/hw_random.h b/include/linux/hw_random.h
index 34a0dc18f327..bee0827766a3 100644
--- a/include/linux/hw_random.h
+++ b/include/linux/hw_random.h
@@ -30,8 +30,7 @@
* Must not be NULL. *OBSOLETE*
* @read: New API. drivers can fill up to max bytes of data
* into the buffer. The buffer is aligned for any type
- * and max is guaranteed to be >= to that alignment
- * (either 4 or 8 depending on architecture).
+ * and max is a multiple of 4 and >= 32 bytes.
* @priv: Private data, for use by the RNG driver.
* @quality: Estimation of true entropy in RNG's bitstream
* (per mill).