s390 updates for 5.19

- Prevent relatively slow PRNO TRNG random number operation
   from being called from interrupt context. That could for
   example cause some network loads to timeout.
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Merge tag 's390-5.19-7' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 fix from Alexander GordeevL

 - Prevent relatively slow PRNO TRNG random number operation from being
   called from interrupt context. That could for example cause some
   network loads to timeout.

* tag 's390-5.19-7' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/archrandom: prevent CPACF trng invocations in interrupt context
This commit is contained in:
Linus Torvalds 2022-07-26 10:03:53 -07:00
commit 5de64d4496

View File

@ -2,7 +2,7 @@
/*
* Kernel interface for the s390 arch_random_* functions
*
* Copyright IBM Corp. 2017, 2020
* Copyright IBM Corp. 2017, 2022
*
* Author: Harald Freudenberger <freude@de.ibm.com>
*
@ -14,6 +14,7 @@
#ifdef CONFIG_ARCH_RANDOM
#include <linux/static_key.h>
#include <linux/preempt.h>
#include <linux/atomic.h>
#include <asm/cpacf.h>
@ -32,7 +33,8 @@ static inline bool __must_check arch_get_random_int(unsigned int *v)
static inline bool __must_check arch_get_random_seed_long(unsigned long *v)
{
if (static_branch_likely(&s390_arch_random_available)) {
if (static_branch_likely(&s390_arch_random_available) &&
in_task()) {
cpacf_trng(NULL, 0, (u8 *)v, sizeof(*v));
atomic64_add(sizeof(*v), &s390_arch_random_counter);
return true;
@ -42,7 +44,8 @@ static inline bool __must_check arch_get_random_seed_long(unsigned long *v)
static inline bool __must_check arch_get_random_seed_int(unsigned int *v)
{
if (static_branch_likely(&s390_arch_random_available)) {
if (static_branch_likely(&s390_arch_random_available) &&
in_task()) {
cpacf_trng(NULL, 0, (u8 *)v, sizeof(*v));
atomic64_add(sizeof(*v), &s390_arch_random_counter);
return true;