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Commit ed424bb3 authored by PrasannaKumar Muralidharan's avatar PrasannaKumar Muralidharan Committed by Herbert Xu
Browse files

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: default avatarPrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 8ff4c191

drivers/char/hw_random/msm-rng.c

+0 −4
Original line number Diff line number Diff line
@@ -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;

drivers/char/hw_random/pic32-rng.c

+0 −3
Original line number Diff line number Diff line
@@ -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) {

drivers/char/hw_random/pseries-rng.c

+2 −3
Original line number Diff line number Diff line
@@ -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;

}



/**

include/linux/hw_random.h

+1 −2
Original line number Diff line number Diff line
@@ -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).