Allow flock cache accounting to be disabled with 'mitigations=off', as
it fits the profile for that option: trusted user space combined with a
performance-impacting mitigation.
Also, for consistency with the other CONFIG_MITIGATION_* options, rename
CONFIG_FLOCK_ACCOUNTING to CONFIG_MITIGATION_FLOCK_ACCOUNTING.
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
Documentation/admin-guide/kernel-parameters.txt | 4 ++++
fs/Kconfig | 2 +-
fs/locks.c | 5 +++--
3 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 24e873351368..b31fe7433b48 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3427,6 +3427,10 @@
ssbd=force-off [ARM64]
tsx_async_abort=off [X86]
+ Software mitigations:
+ ---------------------
+ flock_accounting=off [KNL]
+
Exceptions:
This does not have any effect on
kvm.nx_huge_pages when
diff --git a/fs/Kconfig b/fs/Kconfig
index 591f54a03059..4345b79d3b40 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -129,7 +129,7 @@ config FILE_LOCKING
for filesystems like NFS and for the flock() system
call. Disabling this option saves about 11k.
-config FLOCK_ACCOUNTING
+config MITIGATION_FLOCK_ACCOUNTING
bool "Enable kernel memory accounting for file locks" if EXPERT
depends on FILE_LOCKING
default y
diff --git a/fs/locks.c b/fs/locks.c
index e2799a18c4e8..fd4157ccd504 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -64,6 +64,7 @@
#include <linux/hashtable.h>
#include <linux/percpu.h>
#include <linux/sysctl.h>
+#include <linux/mitigations.h>
#define CREATE_TRACE_POINTS
#include <trace/events/filelock.h>
@@ -2905,7 +2906,7 @@ static int __init proc_locks_init(void)
fs_initcall(proc_locks_init);
#endif
-static bool flock_accounting __ro_after_init = IS_ENABLED(CONFIG_FLOCK_ACCOUNTING);
+static bool flock_accounting __ro_after_init = IS_ENABLED(CONFIG_MITIGATION_FLOCK_ACCOUNTING);
static int __init flock_accounting_cmdline(char *str)
{
@@ -2930,7 +2931,7 @@ static int __init filelock_init(void)
int i;
slab_flags_t flags = SLAB_PANIC;
- if (!flock_accounting)
+ if (mitigations_off() || !flock_accounting)
pr_err(FLOCK_ACCOUNTING_MSG);
else
flags |= SLAB_ACCOUNT;
--
2.43.0
