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authorLinus Torvalds <torvalds@linux-foundation.org>2022-07-26 20:03:53 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-07-26 20:03:53 +0300
commit5de64d44968e4ae66ebdb0a2d08b443f189d3651 (patch)
treecb77a416574ee71ec0d09c01e7d6239408d4ba34
parentcdb281e63874086a650552d36c504ea717a0e0cb (diff)
parent918e75f77af7d2e049bb70469ec0a2c12782d96a (diff)
downloadlinux-5de64d44968e4ae66ebdb0a2d08b443f189d3651.tar.xz
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
-rw-r--r--arch/s390/include/asm/archrandom.h9
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/s390/include/asm/archrandom.h b/arch/s390/include/asm/archrandom.h
index 2c6e1c6ecbe7..4120c428dc37 100644
--- a/arch/s390/include/asm/archrandom.h
+++ b/arch/s390/include/asm/archrandom.h
@@ -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;