From: Jackie Liu <liuyun01@kylinos.cn> mainline inclusion from mainline-v5.19-rc1 commit 83d7d04f9d2ef354858b2a8444aee38e41ec1699 category: bugfix bugzilla: 187071, https://gitee.com/openeuler/kernel/issues/I5DLA7 CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- By printing information, we can friendly prompt the status change information of kfence by dmesg and record by syslog. Also, set kfence_enabled to false only when needed. Link: https://lkml.kernel.org/r/20220518073105.3160335-1-liu.yun@linux.dev Signed-off-by: Jackie Liu <liuyun01@kylinos.cn> Co-developed-by: Marco Elver <elver@google.com> Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Conflicts: mm/kfence/core.c Signed-off-by: Liu Shixin <liushixin2@huawei.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- mm/kfence/core.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/mm/kfence/core.c b/mm/kfence/core.c index 7af797305fdd..d330b6c930c8 100644 --- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -78,8 +78,11 @@ static int param_set_sample_interval(const char *val, const struct kernel_param */ num = max_t(long, 0, num); - if (!num) /* Using 0 to indicate KFENCE is disabled. */ + /* Using 0 to indicate KFENCE is disabled. */ + if (!num && READ_ONCE(kfence_enabled)) { + pr_info("disabled\n"); WRITE_ONCE(kfence_enabled, false); + } *((unsigned long *)kp->arg) = (unsigned long)num; @@ -1120,6 +1123,7 @@ static int kfence_enable_late(void) WRITE_ONCE(kfence_enabled, true); queue_delayed_work(system_unbound_wq, &kfence_timer, 0); + pr_info("re-enabled\n"); return 0; } -- 2.20.1