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: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index ae1d5be..82bc113 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -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 @@
#endif
get_cpu_id(&cpu_id);
+ add_device_randomness(&cpu_id, sizeof(cpu_id));
switch (cpu_id.machine) {
case 0x9672:
#if !defined(CONFIG_64BIT)
@@ -804,6 +807,19 @@
}
/*
+ * 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 @@
/* Setup zfcpdump support */
setup_zfcpdump();
+
+ /* Add system specific data to the random pool */
+ setup_randomness();
}
#ifdef CONFIG_32BIT