Commit bcfcbb6b authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

s390: add system information as device randomness 



The virtual-machine cpu information data block and the cpu-id of
the boot cpu can be used as source of device randomness.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 852ffd0f

arch/s390/kernel/setup.c

+19 −0
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <linux/stddef.h>

#include <linux/unistd.h>

#include <linux/ptrace.h>

#include <linux/random.h>

#include <linux/user.h>

#include <linux/tty.h>

#include <linux/ioport.h>
@@ -61,6 +62,7 @@ 
#include <asm/diag.h>

#include <asm/os_info.h>

#include <asm/sclp.h>

#include <asm/sysinfo.h>

#include "entry.h"



/*
@@ -766,6 +768,7 @@ static void __init setup_hwcaps(void) 
#endif



	get_cpu_id(&cpu_id);

	add_device_randomness(&cpu_id, sizeof(cpu_id));

	switch (cpu_id.machine) {

	case 0x9672:

#if !defined(CONFIG_64BIT)
@@ -803,6 +806,19 @@ static void __init setup_hwcaps(void) 
	}

}



/*

 * Add system information as device randomness

 */

static void __init setup_randomness(void)

{

	struct sysinfo_3_2_2 *vmms;



	vmms = (struct sysinfo_3_2_2 *) alloc_page(GFP_KERNEL);

	if (vmms && stsi(vmms, 3, 2, 2) == 0 && vmms->count)

		add_device_randomness(&vmms, vmms->count);

	free_page((unsigned long) vmms);

}



/*

 * Setup function called from init/main.c just after the banner

 * was printed.
@@ -901,6 +917,9 @@ void __init setup_arch(char **cmdline_p) 


	/* Setup zfcpdump support */

	setup_zfcpdump();



	/* Add system specific data to the random pool */

	setup_randomness();

}



#ifdef CONFIG_32BIT