Commit 07a699bc authored by Vasily Gorbik's avatar Vasily Gorbik
Browse files

s390/kaslr: avoid mixing valid random value and an error code 



0 is a valid random value. To avoid mixing it with error code 0 as an
return code make get_random() take extra argument to output random
value and return an error code.

Reviewed-by: default avatarPhilipp Rudo <prudo@linux.ibm.com>
Reviewed-by: default avatarAlexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 62aacabc

arch/s390/boot/kaslr.c

+5 −5
Original line number Diff line number Diff line
@@ -42,7 +42,7 @@ static int check_prng(void) 
		return PRNG_MODE_TDES;

}



static unsigned long get_random(unsigned long limit)

static int get_random(unsigned long limit, unsigned long *value)

{

	struct prng_parm prng = {

		/* initial parameter block for tdes mode, copied from libica */
@@ -84,9 +84,10 @@ static unsigned long get_random(unsigned long limit) 
			  (u8 *) &random, sizeof(random));

		break;

	default:

		random = 0;

		return -1;

	}

	return random % limit;

	*value = random % limit;

	return 0;

}



unsigned long get_random_base(unsigned long safe_addr)
@@ -143,8 +144,7 @@ unsigned long get_random_base(unsigned long safe_addr) 
		return 0;

	}



	base = get_random(block_sum);

	if (base == 0)

	if (get_random(block_sum, &base))

		return 0;

	if (base < safe_addr)

		base = safe_addr;