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authorLinus Torvalds <torvalds@linux-foundation.org>2016-12-15 02:25:18 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-15 02:25:18 +0100
commita57cb1c1d7974c62a5c80f7869e35b492ace12cd (patch)
tree5a42ee9a668f171143464bc86013954c1bbe94ad /kernel
parentMerge branch 'for-linus' of git://git.kernel.dk/linux-block (diff)
parentradix tree test suite: delete unused rcupdate.c (diff)
downloadlinux-a57cb1c1d7974c62a5c80f7869e35b492ace12cd.tar.xz
linux-a57cb1c1d7974c62a5c80f7869e35b492ace12cd.zip
Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton: - a few misc things - kexec updates - DMA-mapping updates to better support networking DMA operations - IPC updates - various MM changes to improve DAX fault handling - lots of radix-tree changes, mainly to the test suite. All leading up to reimplementing the IDA/IDR code to be a wrapper layer over the radix-tree. However the final trigger-pulling patch is held off for 4.11. * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (114 commits) radix tree test suite: delete unused rcupdate.c radix tree test suite: add new tag check radix-tree: ensure counts are initialised radix tree test suite: cache recently freed objects radix tree test suite: add some more functionality idr: reduce the number of bits per level from 8 to 6 rxrpc: abstract away knowledge of IDR internals tpm: use idr_find(), not idr_find_slowpath() idr: add ida_is_empty radix tree test suite: check multiorder iteration radix-tree: fix replacement for multiorder entries radix-tree: add radix_tree_split_preload() radix-tree: add radix_tree_split radix-tree: add radix_tree_join radix-tree: delete radix_tree_range_tag_if_tagged() radix-tree: delete radix_tree_locate_item() radix-tree: improve multiorder iterators btrfs: fix race in btrfs_free_dummy_fs_info() radix-tree: improve dump output radix-tree: make radix_tree_find_next_bit more useful ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/Makefile1
-rw-r--r--kernel/debug/debug_core.c4
-rw-r--r--kernel/debug/kdb/kdb_io.c37
-rw-r--r--kernel/debug/kdb/kdb_main.c1
-rw-r--r--kernel/debug/kdb/kdb_private.h1
-rw-r--r--kernel/events/uprobes.c4
-rw-r--r--kernel/kcov.c5
-rw-r--r--kernel/kexec_core.c5
-rw-r--r--kernel/printk/printk.c3
-rw-r--r--kernel/relay.c4
-rw-r--r--kernel/signal.c7
-rw-r--r--kernel/sysctl.c8
-rw-r--r--kernel/sysctl_binary.c4
-rw-r--r--kernel/time/alarmtimer.c3
-rw-r--r--kernel/watchdog.c270
-rw-r--r--kernel/watchdog_hld.c227
16 files changed, 287 insertions, 297 deletions
diff --git a/kernel/Makefile b/kernel/Makefile
index eaee9de224bd..12c679f769c6 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -84,6 +84,7 @@ obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_KGDB) += debug/
obj-$(CONFIG_DETECT_HUNG_TASK) += hung_task.o
obj-$(CONFIG_LOCKUP_DETECTOR) += watchdog.o
+obj-$(CONFIG_HARDLOCKUP_DETECTOR) += watchdog_hld.o
obj-$(CONFIG_SECCOMP) += seccomp.o
obj-$(CONFIG_RELAY) += relay.o
obj-$(CONFIG_SYSCTL) += utsname_sysctl.o
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 0874e2edd275..79517e5549f1 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -598,11 +598,11 @@ return_normal:
/*
* Wait for the other CPUs to be notified and be waiting for us:
*/
- time_left = loops_per_jiffy * HZ;
+ time_left = MSEC_PER_SEC;
while (kgdb_do_roundup && --time_left &&
(atomic_read(&masters_in_kgdb) + atomic_read(&slaves_in_kgdb)) !=
online_cpus)
- cpu_relax();
+ udelay(1000);
if (!time_left)
pr_crit("Timed out waiting for secondary CPUs.\n");
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index 98c9011eac78..e74be38245ad 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -30,6 +30,7 @@
char kdb_prompt_str[CMD_BUFLEN];
int kdb_trap_printk;
+int kdb_printf_cpu = -1;
static int kgdb_transition_check(char *buffer)
{
@@ -554,31 +555,26 @@ int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
int linecount;
int colcount;
int logging, saved_loglevel = 0;
- int saved_trap_printk;
- int got_printf_lock = 0;
int retlen = 0;
int fnd, len;
+ int this_cpu, old_cpu;
char *cp, *cp2, *cphold = NULL, replaced_byte = ' ';
char *moreprompt = "more> ";
struct console *c = console_drivers;
- static DEFINE_SPINLOCK(kdb_printf_lock);
unsigned long uninitialized_var(flags);
- preempt_disable();
- saved_trap_printk = kdb_trap_printk;
- kdb_trap_printk = 0;
-
/* Serialize kdb_printf if multiple cpus try to write at once.
* But if any cpu goes recursive in kdb, just print the output,
* even if it is interleaved with any other text.
*/
- if (!KDB_STATE(PRINTF_LOCK)) {
- KDB_STATE_SET(PRINTF_LOCK);
- spin_lock_irqsave(&kdb_printf_lock, flags);
- got_printf_lock = 1;
- atomic_inc(&kdb_event);
- } else {
- __acquire(kdb_printf_lock);
+ local_irq_save(flags);
+ this_cpu = smp_processor_id();
+ for (;;) {
+ old_cpu = cmpxchg(&kdb_printf_cpu, -1, this_cpu);
+ if (old_cpu == -1 || old_cpu == this_cpu)
+ break;
+
+ cpu_relax();
}
diag = kdbgetintenv("LINES", &linecount);
@@ -847,16 +843,9 @@ kdb_print_out:
suspend_grep = 0; /* end of what may have been a recursive call */
if (logging)
console_loglevel = saved_loglevel;
- if (KDB_STATE(PRINTF_LOCK) && got_printf_lock) {
- got_printf_lock = 0;
- spin_unlock_irqrestore(&kdb_printf_lock, flags);
- KDB_STATE_CLEAR(PRINTF_LOCK);
- atomic_dec(&kdb_event);
- } else {
- __release(kdb_printf_lock);
- }
- kdb_trap_printk = saved_trap_printk;
- preempt_enable();
+ /* kdb_printf_cpu locked the code above. */
+ smp_store_release(&kdb_printf_cpu, old_cpu);
+ local_irq_restore(flags);
return retlen;
}
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 2a20c0dfdafc..ca183919d302 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -60,7 +60,6 @@ int kdb_grep_trailing;
* Kernel debugger state flags
*/
int kdb_flags;
-atomic_t kdb_event;
/*
* kdb_lock protects updates to kdb_initial_cpu. Used to
diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
index 75014d7f4568..fc224fbcf954 100644
--- a/kernel/debug/kdb/kdb_private.h
+++ b/kernel/debug/kdb/kdb_private.h
@@ -132,7 +132,6 @@ extern int kdb_state;
#define KDB_STATE_PAGER 0x00000400 /* pager is available */
#define KDB_STATE_GO_SWITCH 0x00000800 /* go is switching
* back to initial cpu */
-#define KDB_STATE_PRINTF_LOCK 0x00001000 /* Holds kdb_printf lock */
#define KDB_STATE_WAIT_IPI 0x00002000 /* Waiting for kdb_ipi() NMI */
#define KDB_STATE_RECURSE 0x00004000 /* Recursive entry to kdb */
#define KDB_STATE_IP_ADJUSTED 0x00008000 /* Restart IP has been
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index f9ec9add2164..215871bda3a2 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -301,7 +301,7 @@ int uprobe_write_opcode(struct mm_struct *mm, unsigned long vaddr,
retry:
/* Read the page with vaddr into memory */
ret = get_user_pages_remote(NULL, mm, vaddr, 1, FOLL_FORCE, &old_page,
- &vma);
+ &vma, NULL);
if (ret <= 0)
return ret;
@@ -1712,7 +1712,7 @@ static int is_trap_at_addr(struct mm_struct *mm, unsigned long vaddr)
* essentially a kernel access to the memory.
*/
result = get_user_pages_remote(NULL, mm, vaddr, 1, FOLL_FORCE, &page,
- NULL);
+ NULL, NULL);
if (result < 0)
return result;
diff --git a/kernel/kcov.c b/kernel/kcov.c
index 3cbb0c879705..cc2fa35ca480 100644
--- a/kernel/kcov.c
+++ b/kernel/kcov.c
@@ -1,11 +1,16 @@
#define pr_fmt(fmt) "kcov: " fmt
#define DISABLE_BRANCH_PROFILING
+#include <linux/atomic.h>
#include <linux/compiler.h>
+#include <linux/errno.h>
+#include <linux/export.h>
#include <linux/types.h>
#include <linux/file.h>
#include <linux/fs.h>
+#include <linux/init.h>
#include <linux/mm.h>
+#include <linux/preempt.h>
#include <linux/printk.h>
#include <linux/sched.h>
#include <linux/slab.h>
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 561675589511..5617cc412444 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -441,6 +441,8 @@ static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
while (hole_end <= crashk_res.end) {
unsigned long i;
+ cond_resched();
+
if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT)
break;
/* See if I overlap any of the segments */
@@ -1467,9 +1469,6 @@ static int __init crash_save_vmcoreinfo_init(void)
#endif
VMCOREINFO_NUMBER(PG_head_mask);
VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
-#ifdef CONFIG_X86
- VMCOREINFO_NUMBER(KERNEL_IMAGE_SIZE);
-#endif
#ifdef CONFIG_HUGETLB_PAGE
VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
#endif
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 577f2288d19f..a3ce35e0fa1e 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1926,7 +1926,8 @@ int vprintk_default(const char *fmt, va_list args)
int r;
#ifdef CONFIG_KGDB_KDB
- if (unlikely(kdb_trap_printk)) {
+ /* Allow to pass printk() to kdb but avoid a recursion. */
+ if (unlikely(kdb_trap_printk && kdb_printf_cpu < 0)) {
r = vkdb_printf(KDB_MSGSRC_PRINTK, fmt, args);
return r;
}
diff --git a/kernel/relay.c b/kernel/relay.c
index da79a109dbeb..8f18d314a96a 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -809,11 +809,11 @@ void relay_subbufs_consumed(struct rchan *chan,
{
struct rchan_buf *buf;
- if (!chan)
+ if (!chan || cpu >= NR_CPUS)
return;
buf = *per_cpu_ptr(chan->buf, cpu);
- if (cpu >= NR_CPUS || !buf || subbufs_consumed > chan->n_subbufs)
+ if (!buf || subbufs_consumed > chan->n_subbufs)
return;
if (subbufs_consumed > buf->subbufs_produced - buf->subbufs_consumed)
diff --git a/kernel/signal.c b/kernel/signal.c
index 29a410780aa9..ae60996fedff 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2491,6 +2491,13 @@ void __set_current_blocked(const sigset_t *newset)
{
struct task_struct *tsk = current;
+ /*
+ * In case the signal mask hasn't changed, there is nothing we need
+ * to do. The current->blocked shouldn't be modified by other task.
+ */
+ if (sigequalsets(&tsk->blocked, newset))
+ return;
+
spin_lock_irq(&tsk->sighand->siglock);
__set_task_blocked(tsk, newset);
spin_unlock_irq(&tsk->sighand->siglock);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 39b3368f6de6..1475d2545b7e 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2389,9 +2389,11 @@ static void validate_coredump_safety(void)
#ifdef CONFIG_COREDUMP
if (suid_dumpable == SUID_DUMP_ROOT &&
core_pattern[0] != '/' && core_pattern[0] != '|') {
- printk(KERN_WARNING "Unsafe core_pattern used with "\
- "suid_dumpable=2. Pipe handler or fully qualified "\
- "core dump path required.\n");
+ printk(KERN_WARNING
+"Unsafe core_pattern used with fs.suid_dumpable=2.\n"
+"Pipe handler or fully qualified core dump path required.\n"
+"Set kernel.core_pattern before fs.suid_dumpable.\n"
+ );
}
#endif
}
diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c
index 6eb99c17dbd8..ece4b177052b 100644
--- a/kernel/sysctl_binary.c
+++ b/kernel/sysctl_binary.c
@@ -1354,8 +1354,8 @@ static void deprecated_sysctl_warning(const int *name, int nlen)
"warning: process `%s' used the deprecated sysctl "
"system call with ", current->comm);
for (i = 0; i < nlen; i++)
- printk("%d.", name[i]);
- printk("\n");
+ printk(KERN_CONT "%d.", name[i]);
+ printk(KERN_CONT "\n");
}
return;
}
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 9b08ca391aed..3921cf7fea8e 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -516,7 +516,8 @@ static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
spin_lock_irqsave(&ptr->it_lock, flags);
if ((ptr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) {
- if (posix_timer_event(ptr, 0) != 0)
+ if (IS_ENABLED(CONFIG_POSIX_TIMERS) &&
+ posix_timer_event(ptr, 0) != 0)
ptr->it_overrun++;
}
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 9acb29f280ec..d4b0fa01cae3 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -24,32 +24,14 @@
#include <asm/irq_regs.h>
#include <linux/kvm_para.h>
-#include <linux/perf_event.h>
#include <linux/kthread.h>
-/*
- * The run state of the lockup detectors is controlled by the content of the
- * 'watchdog_enabled' variable. Each lockup detector has its dedicated bit -
- * bit 0 for the hard lockup detector and bit 1 for the soft lockup detector.
- *
- * 'watchdog_user_enabled', 'nmi_watchdog_enabled' and 'soft_watchdog_enabled'
- * are variables that are only used as an 'interface' between the parameters
- * in /proc/sys/kernel and the internal state bits in 'watchdog_enabled'. The
- * 'watchdog_thresh' variable is handled differently because its value is not
- * boolean, and the lockup detectors are 'suspended' while 'watchdog_thresh'
- * is equal zero.
- */
-#define NMI_WATCHDOG_ENABLED_BIT 0
-#define SOFT_WATCHDOG_ENABLED_BIT 1
-#define NMI_WATCHDOG_ENABLED (1 << NMI_WATCHDOG_ENABLED_BIT)
-#define SOFT_WATCHDOG_ENABLED (1 << SOFT_WATCHDOG_ENABLED_BIT)
-
static DEFINE_MUTEX(watchdog_proc_mutex);
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-static unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED|NMI_WATCHDOG_ENABLED;
+#if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
+unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED|NMI_WATCHDOG_ENABLED;
#else
-static unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED;
+unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED;
#endif
int __read_mostly nmi_watchdog_enabled;
int __read_mostly soft_watchdog_enabled;
@@ -59,9 +41,6 @@ int __read_mostly watchdog_thresh = 10;
#ifdef CONFIG_SMP
int __read_mostly sysctl_softlockup_all_cpu_backtrace;
int __read_mostly sysctl_hardlockup_all_cpu_backtrace;
-#else
-#define sysctl_softlockup_all_cpu_backtrace 0
-#define sysctl_hardlockup_all_cpu_backtrace 0
#endif
static struct cpumask watchdog_cpumask __read_mostly;
unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask);
@@ -100,50 +79,9 @@ static DEFINE_PER_CPU(bool, soft_watchdog_warn);
static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts);
static DEFINE_PER_CPU(unsigned long, soft_lockup_hrtimer_cnt);
static DEFINE_PER_CPU(struct task_struct *, softlockup_task_ptr_saved);
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-static DEFINE_PER_CPU(bool, hard_watchdog_warn);
-static DEFINE_PER_CPU(bool, watchdog_nmi_touch);
static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved);
-static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);
-#endif
static unsigned long soft_lockup_nmi_warn;
-/* boot commands */
-/*
- * Should we panic when a soft-lockup or hard-lockup occurs:
- */
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-unsigned int __read_mostly hardlockup_panic =
- CONFIG_BOOTPARAM_HARDLOCKUP_PANIC_VALUE;
-static unsigned long hardlockup_allcpu_dumped;
-/*
- * We may not want to enable hard lockup detection by default in all cases,
- * for example when running the kernel as a guest on a hypervisor. In these
- * cases this function can be called to disable hard lockup detection. This
- * function should only be executed once by the boot processor before the
- * kernel command line parameters are parsed, because otherwise it is not
- * possible to override this in hardlockup_panic_setup().
- */
-void hardlockup_detector_disable(void)
-{
- watchdog_enabled &= ~NMI_WATCHDOG_ENABLED;
-}
-
-static int __init hardlockup_panic_setup(char *str)
-{
- if (!strncmp(str, "panic", 5))
- hardlockup_panic = 1;
- else if (!strncmp(str, "nopanic", 7))
- hardlockup_panic = 0;
- else if (!strncmp(str, "0", 1))
- watchdog_enabled &= ~NMI_WATCHDOG_ENABLED;
- else if (!strncmp(str, "1", 1))
- watchdog_enabled |= NMI_WATCHDOG_ENABLED;
- return 1;
-}
-__setup("nmi_watchdog=", hardlockup_panic_setup);
-#endif
-
unsigned int __read_mostly softlockup_panic =
CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE;
@@ -264,32 +202,14 @@ void touch_all_softlockup_watchdogs(void)
wq_watchdog_touch(-1);
}
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-void touch_nmi_watchdog(void)
-{
- /*
- * Using __raw here because some code paths have
- * preemption enabled. If preemption is enabled
- * then interrupts should be enabled too, in which
- * case we shouldn't have to worry about the watchdog
- * going off.
- */
- raw_cpu_write(watchdog_nmi_touch, true);
- touch_softlockup_watchdog();
-}
-EXPORT_SYMBOL(touch_nmi_watchdog);
-
-#endif
-
void touch_softlockup_watchdog_sync(void)
{
__this_cpu_write(softlockup_touch_sync, true);
__this_cpu_write(watchdog_touch_ts, 0);
}
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
/* watchdog detector functions */
-static bool is_hardlockup(void)
+bool is_hardlockup(void)
{
unsigned long hrint = __this_cpu_read(hrtimer_interrupts);
@@ -299,7 +219,6 @@ static bool is_hardlockup(void)
__this_cpu_write(hrtimer_interrupts_saved, hrint);
return false;
}
-#endif
static int is_softlockup(unsigned long touch_ts)
{
@@ -313,78 +232,22 @@ static int is_softlockup(unsigned long touch_ts)
return 0;
}
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-
-static struct perf_event_attr wd_hw_attr = {
- .type = PERF_TYPE_HARDWARE,
- .config = PERF_COUNT_HW_CPU_CYCLES,
- .size = sizeof(struct perf_event_attr),
- .pinned = 1,
- .disabled = 1,
-};
-
-/* Callback function for perf event subsystem */
-static void watchdog_overflow_callback(struct perf_event *event,
- struct perf_sample_data *data,
- struct pt_regs *regs)
-{
- /* Ensure the watchdog never gets throttled */
- event->hw.interrupts = 0;
-
- if (__this_cpu_read(watchdog_nmi_touch) == true) {
- __this_cpu_write(watchdog_nmi_touch, false);
- return;
- }
-
- /* check for a hardlockup
- * This is done by making sure our timer interrupt
- * is incrementing. The timer interrupt should have
- * fired multiple times before we overflow'd. If it hasn't
- * then this is a good indication the cpu is stuck
- */
- if (is_hardlockup()) {
- int this_cpu = smp_processor_id();
- struct pt_regs *regs = get_irq_regs();
-
- /* only print hardlockups once */
- if (__this_cpu_read(hard_watchdog_warn) == true)
- return;
-
- pr_emerg("Watchdog detected hard LOCKUP on cpu %d", this_cpu);
- print_modules();
- print_irqtrace_events(current);
- if (regs)
- show_regs(regs);
- else
- dump_stack();
-
- /*
- * Perform all-CPU dump only once to avoid multiple hardlockups
- * generating interleaving traces
- */
- if (sysctl_hardlockup_all_cpu_backtrace &&
- !test_and_set_bit(0, &hardlockup_allcpu_dumped))
- trigger_allbutself_cpu_backtrace();
-
- if (hardlockup_panic)
- nmi_panic(regs, "Hard LOCKUP");
-
- __this_cpu_write(hard_watchdog_warn, true);
- return;
- }
-
- __this_cpu_write(hard_watchdog_warn, false);
- return;
-}
-#endif /* CONFIG_HARDLOCKUP_DETECTOR */
-
static void watchdog_interrupt_count(void)
{
__this_cpu_inc(hrtimer_interrupts);
}
-static int watchdog_nmi_enable(unsigned int cpu);
-static void watchdog_nmi_disable(unsigned int cpu);
+/*
+ * These two functions are mostly architecture specific
+ * defining them as weak here.
+ */
+int __weak watchdog_nmi_enable(unsigned int cpu)
+{
+ return 0;
+}
+void __weak watchdog_nmi_disable(unsigned int cpu)
+{
+}
static int watchdog_enable_all_cpus(void);
static void watchdog_disable_all_cpus(void);
@@ -577,109 +440,6 @@ static void watchdog(unsigned int cpu)
watchdog_nmi_disable(cpu);
}
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-/*
- * People like the simple clean cpu node info on boot.
- * Reduce the watchdog noise by only printing messages
- * that are different from what cpu0 displayed.
- */
-static unsigned long cpu0_err;
-
-static int watchdog_nmi_enable(unsigned int cpu)
-{
- struct perf_event_attr *wd_attr;
- struct perf_event *event = per_cpu(watchdog_ev, cpu);
-
- /* nothing to do if the hard lockup detector is disabled */
- if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED))
- goto out;
-
- /* is it already setup and enabled? */
- if (event && event->state > PERF_EVENT_STATE_OFF)
- goto out;
-
- /* it is setup but not enabled */
- if (event != NULL)
- goto out_enable;
-
- wd_attr = &wd_hw_attr;
- wd_attr->sample_period = hw_nmi_get_sample_period(watchdog_thresh);
-
- /* Try to register using hardware perf events */
- event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback, NULL);
-
- /* save cpu0 error for future comparision */
- if (cpu == 0 && IS_ERR(event))
- cpu0_err = PTR_ERR(event);
-
- if (!IS_ERR(event)) {
- /* only print for cpu0 or different than cpu0 */
- if (cpu == 0 || cpu0_err)
- pr_info("enabled on all CPUs, permanently consumes one hw-PMU counter.\n");
- goto out_save;
- }
-
- /*
- * Disable the hard lockup detector if _any_ CPU fails to set up
- * set up the hardware perf event. The watchdog() function checks
- * the NMI_WATCHDOG_ENABLED bit periodically.
- *
- * The barriers are for syncing up watchdog_enabled across all the
- * cpus, as clear_bit() does not use barriers.
- */
- smp_mb__before_atomic();
- clear_bit(NMI_WATCHDOG_ENABLED_BIT, &watchdog_enabled);
- smp_mb__after_atomic();
-
- /* skip displaying the same error again */
- if (cpu > 0 && (PTR_ERR(event) == cpu0_err))
- return PTR_ERR(event);
-
- /* vary the KERN level based on the returned errno */
- if (PTR_ERR(event) == -EOPNOTSUPP)
- pr_info("disabled (cpu%i): not supported (no LAPIC?)\n", cpu);
- else if (PTR_ERR(event) == -ENOENT)
- pr_warn("disabled (cpu%i): hardware events not enabled\n",
- cpu);
- else
- pr_err("disabled (cpu%i): unable to create perf event: %ld\n",
- cpu, PTR_ERR(event));
-
- pr_info("Shutting down hard lockup detector on all cpus\n");
-
- return PTR_ERR(event);
-
- /* success path */
-out_save:
- per_cpu(watchdog_ev, cpu) = event;
-out_enable:
- perf_event_enable(per_cpu(watchdog_ev, cpu));
-out:
- return 0;
-}
-
-static void watchdog_nmi_disable(unsigned int cpu)
-{
- struct perf_event *event = per_cpu(watchdog_ev, cpu);
-
- if (event) {
- perf_event_disable(event);
- per_cpu(watchdog_ev, cpu) = NULL;
-
- /* should be in cleanup, but blocks oprofile */
- perf_event_release_kernel(event);
- }
- if (cpu == 0) {
- /* watchdog_nmi_enable() expects this to be zero initially. */
- cpu0_err = 0;
- }
-}
-
-#else
-static int watchdog_nmi_enable(unsigned int cpu) { return 0; }
-static void watchdog_nmi_disable(unsigned int cpu) { return; }
-#endif /* CONFIG_HARDLOCKUP_DETECTOR */
-
static struct smp_hotplug_thread watchdog_threads = {
.store = &softlockup_watchdog,
.thread_should_run = watchdog_should_run,
diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c
new file mode 100644
index 000000000000..84016c8aee6b
--- /dev/null
+++ b/kernel/watchdog_hld.c
@@ -0,0 +1,227 @@
+/*
+ * Detect hard lockups on a system
+ *
+ * started by Don Zickus, Copyright (C) 2010 Red Hat, Inc.
+ *
+ * Note: Most of this code is borrowed heavily from the original softlockup
+ * detector, so thanks to Ingo for the initial implementation.
+ * Some chunks also taken from the old x86-specific nmi watchdog code, thanks
+ * to those contributors as well.
+ */
+
+#define pr_fmt(fmt) "NMI watchdog: " fmt
+
+#include <linux/nmi.h>
+#include <linux/module.h>
+#include <asm/irq_regs.h>
+#include <linux/perf_event.h>
+
+static DEFINE_PER_CPU(bool, hard_watchdog_warn);
+static DEFINE_PER_CPU(bool, watchdog_nmi_touch);
+static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);
+
+/* boot commands */
+/*
+ * Should we panic when a soft-lockup or hard-lockup occurs:
+ */
+unsigned int __read_mostly hardlockup_panic =
+ CONFIG_BOOTPARAM_HARDLOCKUP_PANIC_VALUE;
+static unsigned long hardlockup_allcpu_dumped;
+/*
+ * We may not want to enable hard lockup detection by default in all cases,
+ * for example when running the kernel as a guest on a hypervisor. In these
+ * cases this function can be called to disable hard lockup detection. This
+ * function should only be executed once by the boot processor before the
+ * kernel command line parameters are parsed, because otherwise it is not
+ * possible to override this in hardlockup_panic_setup().
+ */
+void hardlockup_detector_disable(void)
+{
+ watchdog_enabled &= ~NMI_WATCHDOG_ENABLED;
+}
+
+static int __init hardlockup_panic_setup(char *str)
+{
+ if (!strncmp(str, "panic", 5))
+ hardlockup_panic = 1;
+ else if (!strncmp(str, "nopanic", 7))
+ hardlockup_panic = 0;
+ else if (!strncmp(str, "0", 1))
+ watchdog_enabled &= ~NMI_WATCHDOG_ENABLED;
+ else if (!strncmp(str, "1", 1))
+ watchdog_enabled |= NMI_WATCHDOG_ENABLED;
+ return 1;
+}
+__setup("nmi_watchdog=", hardlockup_panic_setup);
+
+void touch_nmi_watchdog(void)
+{
+ /*
+ * Using __raw here because some code paths have
+ * preemption enabled. If preemption is enabled
+ * then interrupts should be enabled too, in which
+ * case we shouldn't have to worry about the watchdog
+ * going off.
+ */
+ raw_cpu_write(watchdog_nmi_touch, true);
+ touch_softlockup_watchdog();
+}
+EXPORT_SYMBOL(touch_nmi_watchdog);
+
+static struct perf_event_attr wd_hw_attr = {
+ .type = PERF_TYPE_HARDWARE,
+ .config = PERF_COUNT_HW_CPU_CYCLES,
+ .size = sizeof(struct perf_event_attr),
+ .pinned = 1,
+ .disabled = 1,
+};
+
+/* Callback function for perf event subsystem */
+static void watchdog_overflow_callback(struct perf_event *event,
+ struct perf_sample_data *data,
+ struct pt_regs *regs)
+{
+ /* Ensure the watchdog never gets throttled */
+ event->hw.interrupts = 0;
+
+ if (__this_cpu_read(watchdog_nmi_touch) == true) {
+ __this_cpu_write(watchdog_nmi_touch, false);
+ return;
+ }
+
+ /* check for a hardlockup
+ * This is done by making sure our timer interrupt
+ * is incrementing. The timer interrupt should have
+ * fired multiple times before we overflow'd. If it hasn't
+ * then this is a good indication the cpu is stuck
+ */
+ if (is_hardlockup()) {
+ int this_cpu = smp_processor_id();
+
+ /* only print hardlockups once */
+ if (__this_cpu_read(hard_watchdog_warn) == true)
+ return;
+
+ pr_emerg("Watchdog detected hard LOCKUP on cpu %d", this_cpu);
+ print_modules();
+ print_irqtrace_events(current);
+ if (regs)
+ show_regs(regs);
+ else
+ dump_stack();
+
+ /*
+ * Perform all-CPU dump only once to avoid multiple hardlockups
+ * generating interleaving traces
+ */
+ if (sysctl_hardlockup_all_cpu_backtrace &&
+ !test_and_set_bit(0, &hardlockup_allcpu_dumped))
+ trigger_allbutself_cpu_backtrace();
+
+ if (hardlockup_panic)
+ nmi_panic(regs, "Hard LOCKUP");
+
+ __this_cpu_write(hard_watchdog_warn, true);
+ return;
+ }
+
+ __this_cpu_write(hard_watchdog_warn, false);
+ return;
+}
+
+/*
+ * People like the simple clean cpu node info on boot.
+ * Reduce the watchdog noise by only printing messages
+ * that are different from what cpu0 displayed.
+ */
+static unsigned long cpu0_err;
+
+int watchdog_nmi_enable(unsigned int cpu)
+{
+ struct perf_event_attr *wd_attr;
+ struct perf_event *event = per_cpu(watchdog_ev, cpu);
+
+ /* nothing to do if the hard lockup detector is disabled */
+ if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED))
+ goto out;
+
+ /* is it already setup and enabled? */
+ if (event && event->state > PERF_EVENT_STATE_OFF)
+ goto out;
+
+ /* it is setup but not enabled */
+ if (event != NULL)
+ goto out_enable;
+
+ wd_attr = &wd_hw_attr;
+ wd_attr->sample_period = hw_nmi_get_sample_period(watchdog_thresh);
+
+ /* Try to register using hardware perf events */
+ event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback, NULL);
+
+ /* save cpu0 error for future comparision */
+ if (cpu == 0 && IS_ERR(event))
+ cpu0_err = PTR_ERR(event);
+
+ if (!IS_ERR(event)) {
+ /* only print for cpu0 or different than cpu0 */
+ if (cpu == 0 || cpu0_err)
+ pr_info("enabled on all CPUs, permanently consumes one hw-PMU counter.\n");
+ goto out_save;
+ }
+
+ /*
+ * Disable the hard lockup detector if _any_ CPU fails to set up
+ * set up the hardware perf event. The watchdog() function checks
+ * the NMI_WATCHDOG_ENABLED bit periodically.
+ *
+ * The barriers are for syncing up watchdog_enabled across all the
+ * cpus, as clear_bit() does not use barriers.
+ */
+ smp_mb__before_atomic();
+ clear_bit(NMI_WATCHDOG_ENABLED_BIT, &watchdog_enabled);
+ smp_mb__after_atomic();
+
+ /* skip displaying the same error again */
+ if (cpu > 0 && (PTR_ERR(event) == cpu0_err))
+ return PTR_ERR(event);
+
+ /* vary the KERN level based on the returned errno */
+ if (PTR_ERR(event) == -EOPNOTSUPP)
+ pr_info("disabled (cpu%i): not supported (no LAPIC?)\n", cpu);
+ else if (PTR_ERR(event) == -ENOENT)
+ pr_warn("disabled (cpu%i): hardware events not enabled\n",
+ cpu);
+ else
+ pr_err("disabled (cpu%i): unable to create perf event: %ld\n",
+ cpu, PTR_ERR(event));
+
+ pr_info("Shutting down hard lockup detector on all cpus\n");
+
+ return PTR_ERR(event);
+
+ /* success path */
+out_save:
+ per_cpu(watchdog_ev, cpu) = event;
+out_enable:
+ perf_event_enable(per_cpu(watchdog_ev, cpu));
+out:
+ return 0;
+}
+
+void watchdog_nmi_disable(unsigned int cpu)
+{
+ struct perf_event *event = per_cpu(watchdog_ev, cpu);
+
+ if (event) {
+ perf_event_disable(event);
+ per_cpu(watchdog_ev, cpu) = NULL;
+
+ /* should be in cleanup, but blocks oprofile */
+ perf_event_release_kernel(event);
+ }
+ if (cpu == 0) {
+ /* watchdog_nmi_enable() expects this to be zero initially. */
+ cpu0_err = 0;
+ }
+}