[PATCH 1/4] hung_task: Move hung_task sysctl interface to hung_task_sysctl.c
From: Xiaoming Ni
Date: Fri May 15 2020 - 00:34:06 EST
Move hung_task sysctl interface to hung_task_sysctl.c.
Use register_sysctl() to register the sysctl interface to avoid
merge conflicts when different features modify sysctl.c at the same time.
Signed-off-by: Xiaoming Ni <nixiaoming@xxxxxxxxxx>
---
include/linux/sched/sysctl.h | 8 +----
kernel/Makefile | 4 ++-
kernel/hung_task.c | 6 ++--
kernel/hung_task.h | 21 ++++++++++++
kernel/hung_task_sysctl.c | 80 ++++++++++++++++++++++++++++++++++++++++++++
kernel/sysctl.c | 50 ---------------------------
6 files changed, 108 insertions(+), 61 deletions(-)
create mode 100644 kernel/hung_task.h
create mode 100644 kernel/hung_task_sysctl.c
diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h
index d4f6215..c075e09 100644
--- a/include/linux/sched/sysctl.h
+++ b/include/linux/sched/sysctl.h
@@ -7,14 +7,8 @@
struct ctl_table;
#ifdef CONFIG_DETECT_HUNG_TASK
-extern int sysctl_hung_task_check_count;
-extern unsigned int sysctl_hung_task_panic;
+/* used for hung_task and block/ */
extern unsigned long sysctl_hung_task_timeout_secs;
-extern unsigned long sysctl_hung_task_check_interval_secs;
-extern int sysctl_hung_task_warnings;
-extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
- void __user *buffer,
- size_t *lenp, loff_t *ppos);
#else
/* Avoid need for ifdefs elsewhere in the code */
enum { sysctl_hung_task_timeout_secs = 0 };
diff --git a/kernel/Makefile b/kernel/Makefile
index 4cb4130..c16934bf 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -84,7 +84,9 @@ obj-$(CONFIG_KCOV) += kcov.o
obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_FAIL_FUNCTION) += fail_function.o
obj-$(CONFIG_KGDB) += debug/
-obj-$(CONFIG_DETECT_HUNG_TASK) += hung_task.o
+obj-$(CONFIG_DETECT_HUNG_TASK) += hung_tasks.o
+hung_tasks-y := hung_task.o
+hung_tasks-$(CONFIG_SYSCTL) += hung_task_sysctl.o
obj-$(CONFIG_LOCKUP_DETECTOR) += watchdog.o
obj-$(CONFIG_HARDLOCKUP_DETECTOR_PERF) += watchdog_hld.o
obj-$(CONFIG_SECCOMP) += seccomp.o
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 14a625c..bfe6e25 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -15,15 +15,13 @@
#include <linux/kthread.h>
#include <linux/lockdep.h>
#include <linux/export.h>
-#include <linux/sysctl.h>
#include <linux/suspend.h>
#include <linux/utsname.h>
#include <linux/sched/signal.h>
#include <linux/sched/debug.h>
-#include <linux/sched/sysctl.h>
#include <trace/events/sched.h>
-
+#include "hung_task.h"
/*
* The number of tasks checked:
*/
@@ -298,6 +296,8 @@ static int watchdog(void *dummy)
static int __init hung_task_init(void)
{
+ hung_task_sysctl_init();
+
atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
/* Disable hung task detector on suspend */
diff --git a/kernel/hung_task.h b/kernel/hung_task.h
new file mode 100644
index 00000000..2fa6a19
--- /dev/null
+++ b/kernel/hung_task.h
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * hung_task sysctl data and function
+ */
+#ifndef KERNEL_HUNG_TASK_H_
+#define KERNEL_HUNG_TASK_H_
+#include <linux/sched/sysctl.h>
+extern int sysctl_hung_task_check_count;
+extern unsigned int sysctl_hung_task_panic;
+extern unsigned long sysctl_hung_task_check_interval_secs;
+extern int sysctl_hung_task_warnings;
+extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
+ void __user *buffer,
+ size_t *lenp, loff_t *ppos);
+#ifdef CONFIG_SYSCTL
+extern void __init hung_task_sysctl_init(void);
+#else
+#define hung_task_sysctl_init() do { } while (0)
+#endif
+
+#endif
diff --git a/kernel/hung_task_sysctl.c b/kernel/hung_task_sysctl.c
new file mode 100644
index 00000000..5b10d4e
--- /dev/null
+++ b/kernel/hung_task_sysctl.c
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * register sysctl for hung_task
+ *
+ */
+
+#include <linux/sysctl.h>
+#include <linux/sched/sysctl.h>
+#include <linux/kmemleak.h>
+#include "hung_task.h"
+
+/*
+ * This is needed for proc_doulongvec_minmax of sysctl_hung_task_timeout_secs
+ * and hung_task_check_interval_secs
+ */
+static unsigned long hung_task_timeout_max = (LONG_MAX / HZ);
+static int neg_one = -1;
+static struct ctl_table hung_task_sysctls[] = {
+ {
+ .procname = "hung_task_panic",
+ .data = &sysctl_hung_task_panic,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_ONE,
+ },
+ {
+ .procname = "hung_task_check_count",
+ .data = &sysctl_hung_task_check_count,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ },
+ {
+ .procname = "hung_task_timeout_secs",
+ .data = &sysctl_hung_task_timeout_secs,
+ .maxlen = sizeof(unsigned long),
+ .mode = 0644,
+ .proc_handler = proc_dohung_task_timeout_secs,
+ .extra2 = &hung_task_timeout_max,
+ },
+ {
+ .procname = "hung_task_check_interval_secs",
+ .data = &sysctl_hung_task_check_interval_secs,
+ .maxlen = sizeof(unsigned long),
+ .mode = 0644,
+ .proc_handler = proc_dohung_task_timeout_secs,
+ .extra2 = &hung_task_timeout_max,
+ },
+ {
+ .procname = "hung_task_warnings",
+ .data = &sysctl_hung_task_warnings,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &neg_one,
+ },
+ {}
+};
+
+/*
+ * The hung task sysctl has a default value.
+ * Even if register_sysctl() fails, it does not affect the main function of
+ * the hung task. At the same time, during the system initialization phase,
+ * malloc small memory will almost never fail.
+ * So the return value is ignored here
+ */
+void __init hung_task_sysctl_init(void)
+{
+ struct ctl_table_header *srt = register_sysctl("kernel", hung_task_sysctls);
+
+ if (unlikely(!srt)) {
+ pr_err("%s fail\n", __func__);
+ return;
+ }
+ kmemleak_not_leak(srt);
+}
+
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index b9ff323..20adae0 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -149,13 +149,6 @@
static int ngroups_max = NGROUPS_MAX;
static const int cap_last_cap = CAP_LAST_CAP;
-/*
- * This is needed for proc_doulongvec_minmax of sysctl_hung_task_timeout_secs
- * and hung_task_check_interval_secs
- */
-#ifdef CONFIG_DETECT_HUNG_TASK
-static unsigned long hung_task_timeout_max = (LONG_MAX/HZ);
-#endif
#ifdef CONFIG_INOTIFY_USER
#include <linux/inotify.h>
@@ -1087,49 +1080,6 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
.proc_handler = proc_dointvec,
},
#endif
-#ifdef CONFIG_DETECT_HUNG_TASK
- {
- .procname = "hung_task_panic",
- .data = &sysctl_hung_task_panic,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE,
- },
- {
- .procname = "hung_task_check_count",
- .data = &sysctl_hung_task_check_count,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = SYSCTL_ZERO,
- },
- {
- .procname = "hung_task_timeout_secs",
- .data = &sysctl_hung_task_timeout_secs,
- .maxlen = sizeof(unsigned long),
- .mode = 0644,
- .proc_handler = proc_dohung_task_timeout_secs,
- .extra2 = &hung_task_timeout_max,
- },
- {
- .procname = "hung_task_check_interval_secs",
- .data = &sysctl_hung_task_check_interval_secs,
- .maxlen = sizeof(unsigned long),
- .mode = 0644,
- .proc_handler = proc_dohung_task_timeout_secs,
- .extra2 = &hung_task_timeout_max,
- },
- {
- .procname = "hung_task_warnings",
- .data = &sysctl_hung_task_warnings,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = &neg_one,
- },
-#endif
#ifdef CONFIG_RT_MUTEXES
{
.procname = "max_lock_depth",
--
1.8.5.6