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-rw-r--r--kernel/cpu.c20
-rw-r--r--kernel/debug/debug_core.c12
-rw-r--r--kernel/debug/kdb/kdb_io.c12
-rw-r--r--kernel/events/ring_buffer.c31
-rw-r--r--kernel/events/uprobes.c58
-rw-r--r--kernel/fork.c19
-rw-r--r--kernel/irq/pm.c12
-rw-r--r--kernel/panic.c13
-rw-r--r--kernel/power/Kconfig15
-rw-r--r--kernel/power/Makefile1
-rw-r--r--kernel/power/suspend.c15
-rw-r--r--kernel/power/suspend_time.c111
-rw-r--r--kernel/printk.c2924
-rw-r--r--kernel/sched/core.c13
-rw-r--r--kernel/sys.c145
-rw-r--r--kernel/sysctl.c17
-rw-r--r--kernel/time/alarmtimer.c2
-rw-r--r--kernel/trace/Kconfig3
-rw-r--r--kernel/trace/Makefile1
-rw-r--r--kernel/trace/gpu-traces.c23
-rw-r--r--kernel/trace/trace.c104
-rw-r--r--kernel/trace/trace.h2
-rw-r--r--kernel/trace/trace_functions_graph.c12
-rw-r--r--kernel/trace/trace_output.c182
-rw-r--r--kernel/watchdog.c123
25 files changed, 3830 insertions, 40 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index d7f07a2da5a6..63d5342f0f01 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -723,3 +723,23 @@ void init_cpu_online(const struct cpumask *src)
{
cpumask_copy(to_cpumask(cpu_online_bits), src);
}
+
+static ATOMIC_NOTIFIER_HEAD(idle_notifier);
+
+void idle_notifier_register(struct notifier_block *n)
+{
+ atomic_notifier_chain_register(&idle_notifier, n);
+}
+EXPORT_SYMBOL_GPL(idle_notifier_register);
+
+void idle_notifier_unregister(struct notifier_block *n)
+{
+ atomic_notifier_chain_unregister(&idle_notifier, n);
+}
+EXPORT_SYMBOL_GPL(idle_notifier_unregister);
+
+void idle_notifier_call_chain(unsigned long val)
+{
+ atomic_notifier_call_chain(&idle_notifier, val, NULL);
+}
+EXPORT_SYMBOL_GPL(idle_notifier_call_chain);
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 0506d447aed2..2d4438b14b42 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -86,6 +86,10 @@ static int kgdb_use_con;
bool dbg_is_early = true;
/* Next cpu to become the master debug core */
int dbg_switch_cpu;
+/* Flag for entering kdb when a panic occurs */
+static bool break_on_panic = true;
+/* Flag for entering kdb when an exception occurs */
+static bool break_on_exception = true;
/* Use kdb or gdbserver mode */
int dbg_kdb_mode = 1;
@@ -100,6 +104,8 @@ early_param("kgdbcon", opt_kgdb_con);
module_param(kgdb_use_con, int, 0644);
module_param(kgdbreboot, int, 0644);
+module_param(break_on_panic, bool, 0644);
+module_param(break_on_exception, bool, 0644);
/*
* Holds information about breakpoints in a kernel. These breakpoints are
@@ -678,6 +684,9 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
if (arch_kgdb_ops.enable_nmi)
arch_kgdb_ops.enable_nmi(0);
+ if (unlikely(signo != SIGTRAP && !break_on_exception))
+ return 1;
+
ks->cpu = raw_smp_processor_id();
ks->ex_vector = evector;
ks->signo = signo;
@@ -784,6 +793,9 @@ static int kgdb_panic_event(struct notifier_block *self,
unsigned long val,
void *data)
{
+ if (!break_on_panic)
+ return NOTIFY_DONE;
+
if (dbg_kdb_mode)
kdb_printf("PANIC: %s\n", (char *)data);
kgdb_breakpoint();
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index 14ff4849262c..4b0fb2fb779c 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -216,7 +216,7 @@ static char *kdb_read(char *buffer, size_t bufsize)
int i;
int diag, dtab_count;
int key;
-
+ static int last_crlf;
diag = kdbgetintenv("DTABCOUNT", &dtab_count);
if (diag)
@@ -237,6 +237,9 @@ poll_again:
return buffer;
if (key != 9)
tab = 0;
+ if (key != 10 && key != 13)
+ last_crlf = 0;
+
switch (key) {
case 8: /* backspace */
if (cp > buffer) {
@@ -254,7 +257,12 @@ poll_again:
*cp = tmp;
}
break;
- case 13: /* enter */
+ case 10: /* new line */
+ case 13: /* carriage return */
+ /* handle \n after \r */
+ if (last_crlf && last_crlf != key)
+ break;
+ last_crlf = key;
*lastchar++ = '\n';
*lastchar++ = '\0';
if (!KDB_STATE(KGDB_TRANS)) {
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index cd55144270b5..9c2ddfbf4525 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -87,10 +87,31 @@ again:
goto out;
/*
- * Publish the known good head. Rely on the full barrier implied
- * by atomic_dec_and_test() order the rb->head read and this
- * write.
+ * Since the mmap() consumer (userspace) can run on a different CPU:
+ *
+ * kernel user
+ *
+ * READ ->data_tail READ ->data_head
+ * smp_mb() (A) smp_rmb() (C)
+ * WRITE $data READ $data
+ * smp_wmb() (B) smp_mb() (D)
+ * STORE ->data_head WRITE ->data_tail
+ *
+ * Where A pairs with D, and B pairs with C.
+ *
+ * I don't think A needs to be a full barrier because we won't in fact
+ * write data until we see the store from userspace. So we simply don't
+ * issue the data WRITE until we observe it. Be conservative for now.
+ *
+ * OTOH, D needs to be a full barrier since it separates the data READ
+ * from the tail WRITE.
+ *
+ * For B a WMB is sufficient since it separates two WRITEs, and for C
+ * an RMB is sufficient since it separates two READs.
+ *
+ * See perf_output_begin().
*/
+ smp_wmb();
rb->user_page->data_head = head;
/*
@@ -154,9 +175,11 @@ int perf_output_begin(struct perf_output_handle *handle,
* Userspace could choose to issue a mb() before updating the
* tail pointer. So that all reads will be completed before the
* write is issued.
+ *
+ * See perf_output_put_handle().
*/
tail = ACCESS_ONCE(rb->user_page->data_tail);
- smp_rmb();
+ smp_mb();
offset = head = local_read(&rb->head);
head += size;
if (unlikely(!perf_output_space(rb, tail, offset, head)))
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index ad8e1bdca70e..cb01d827ae89 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -248,6 +248,12 @@ static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t
* have fixed length instructions.
*/
+void __weak arch_uprobe_write_opcode(struct arch_uprobe *auprobe, void *vaddr,
+ uprobe_opcode_t opcode)
+{
+ memcpy(vaddr, &opcode, UPROBE_SWBP_INSN_SIZE);
+}
+
/*
* write_opcode - write the opcode at a given virtual address.
* @mm: the probed process address space.
@@ -260,11 +266,12 @@ static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t
* For mm @mm, write the opcode at @vaddr.
* Return 0 (success) or a negative errno.
*/
-static int write_opcode(struct mm_struct *mm, unsigned long vaddr,
- uprobe_opcode_t opcode)
+static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
+ unsigned long vaddr, uprobe_opcode_t opcode)
{
struct page *old_page, *new_page;
struct vm_area_struct *vma;
+ void *vaddr_new;
int ret;
retry:
@@ -285,7 +292,10 @@ retry:
__SetPageUptodate(new_page);
copy_highpage(new_page, old_page);
- copy_to_page(new_page, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE);
+ vaddr_new = kmap_atomic(new_page);
+ arch_uprobe_write_opcode(auprobe, vaddr_new + (vaddr & ~PAGE_MASK),
+ opcode);
+ kunmap_atomic(vaddr_new);
ret = anon_vma_prepare(vma);
if (ret)
@@ -314,7 +324,7 @@ put_old:
*/
int __weak set_swbp(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr)
{
- return write_opcode(mm, vaddr, UPROBE_SWBP_INSN);
+ return write_opcode(auprobe, mm, vaddr, UPROBE_SWBP_INSN);
}
/**
@@ -329,7 +339,8 @@ int __weak set_swbp(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned
int __weak
set_orig_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr)
{
- return write_opcode(mm, vaddr, *(uprobe_opcode_t *)auprobe->insn);
+ return write_opcode(auprobe, mm, vaddr,
+ *(uprobe_opcode_t *)auprobe->insn);
}
static int match_uprobe(struct uprobe *l, struct uprobe *r)
@@ -1238,6 +1249,11 @@ static unsigned long xol_take_insn_slot(struct xol_area *area)
return slot_addr;
}
+void __weak arch_uprobe_xol_copy(struct arch_uprobe *auprobe, void *vaddr)
+{
+ memcpy(vaddr, auprobe->insn, MAX_UINSN_BYTES);
+}
+
/*
* xol_get_insn_slot - allocate a slot for xol.
* Returns the allocated slot address or 0.
@@ -1246,6 +1262,7 @@ static unsigned long xol_get_insn_slot(struct uprobe *uprobe)
{
struct xol_area *area;
unsigned long xol_vaddr;
+ void *kaddr;
area = get_xol_area();
if (!area)
@@ -1256,7 +1273,9 @@ static unsigned long xol_get_insn_slot(struct uprobe *uprobe)
return 0;
/* Initialize the slot */
- copy_to_page(area->page, xol_vaddr, uprobe->arch.insn, MAX_UINSN_BYTES);
+ kaddr = kmap_atomic(area->page);
+ arch_uprobe_xol_copy(&uprobe->arch, kaddr + (xol_vaddr & ~PAGE_MASK));
+ kunmap_atomic(kaddr);
/*
* We probably need flush_icache_user_range() but it needs vma.
* This should work on supported architectures too.
@@ -1732,9 +1751,6 @@ static void handle_swbp(struct pt_regs *regs)
return;
}
- /* change it in advance for ->handler() and restart */
- instruction_pointer_set(regs, bp_vaddr);
-
/*
* TODO: move copy_insn/etc into _register and remove this hack.
* After we hit the bp, _unregister + _register can install the
@@ -1742,16 +1758,26 @@ static void handle_swbp(struct pt_regs *regs)
*/
smp_rmb(); /* pairs with wmb() in install_breakpoint() */
if (unlikely(!test_bit(UPROBE_COPY_INSN, &uprobe->flags)))
- goto out;
+ goto restart;
handler_chain(uprobe, regs);
+
+ if (arch_uprobe_ignore(&uprobe->arch, regs))
+ goto out;
+
if (can_skip_sstep(uprobe, regs))
goto out;
if (!pre_ssout(uprobe, regs, bp_vaddr))
return;
- /* can_skip_sstep() succeeded, or restart if can't singlestep */
+restart:
+ /*
+ * cannot singlestep; cannot skip instruction;
+ * re-execute the instruction.
+ */
+ instruction_pointer_set(regs, bp_vaddr);
+
out:
put_uprobe(uprobe);
}
@@ -1845,8 +1871,14 @@ static struct notifier_block uprobe_exception_nb = {
.priority = INT_MAX-1, /* notified after kprobes, kgdb */
};
+int __weak __init arch_uprobes_init(void)
+{
+ return 0;
+}
+
static int __init init_uprobes(void)
{
+ int ret;
int i;
for (i = 0; i < UPROBES_HASH_SZ; i++)
@@ -1855,6 +1887,10 @@ static int __init init_uprobes(void)
if (percpu_init_rwsem(&dup_mmap_sem))
return -ENOMEM;
+ ret = arch_uprobes_init();
+ if (ret)
+ return ret;
+
return register_die_notifier(&uprobe_exception_nb);
}
module_init(init_uprobes);
diff --git a/kernel/fork.c b/kernel/fork.c
index 086fe73ad6bd..33da8588c898 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -198,6 +198,9 @@ struct kmem_cache *vm_area_cachep;
/* SLAB cache for mm_struct structures (tsk->mm) */
static struct kmem_cache *mm_cachep;
+/* Notifier list called when a task struct is freed */
+static ATOMIC_NOTIFIER_HEAD(task_free_notifier);
+
static void account_kernel_stack(struct thread_info *ti, int account)
{
struct zone *zone = page_zone(virt_to_page(ti));
@@ -231,6 +234,18 @@ static inline void put_signal_struct(struct signal_struct *sig)
free_signal_struct(sig);
}
+int task_free_register(struct notifier_block *n)
+{
+ return atomic_notifier_chain_register(&task_free_notifier, n);
+}
+EXPORT_SYMBOL(task_free_register);
+
+int task_free_unregister(struct notifier_block *n)
+{
+ return atomic_notifier_chain_unregister(&task_free_notifier, n);
+}
+EXPORT_SYMBOL(task_free_unregister);
+
void __put_task_struct(struct task_struct *tsk)
{
WARN_ON(!tsk->exit_state);
@@ -242,6 +257,7 @@ void __put_task_struct(struct task_struct *tsk)
delayacct_tsk_free(tsk);
put_signal_struct(tsk->signal);
+ atomic_notifier_call_chain(&task_free_notifier, 0, tsk);
if (!profile_handoff_task(tsk))
free_task(tsk);
}
@@ -689,7 +705,8 @@ struct mm_struct *mm_access(struct task_struct *task, unsigned int mode)
mm = get_task_mm(task);
if (mm && mm != current->mm &&
- !ptrace_may_access(task, mode)) {
+ !ptrace_may_access(task, mode) &&
+ !capable(CAP_SYS_RESOURCE)) {
mmput(mm);
mm = ERR_PTR(-EACCES);
}
diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c
index cb228bf21760..fe4b09cf829c 100644
--- a/kernel/irq/pm.c
+++ b/kernel/irq/pm.c
@@ -103,14 +103,14 @@ int check_wakeup_irqs(void)
int irq;
for_each_irq_desc(irq, desc) {
- /*
- * Only interrupts which are marked as wakeup source
- * and have not been disabled before the suspend check
- * can abort suspend.
- */
if (irqd_is_wakeup_set(&desc->irq_data)) {
- if (desc->depth == 1 && desc->istate & IRQS_PENDING)
+ if (desc->istate & IRQS_PENDING) {
+ pr_info("Wakeup IRQ %d %s pending, suspend aborted\n",
+ irq,
+ desc->action && desc->action->name ?
+ desc->action->name : "");
return -EBUSY;
+ }
continue;
}
/*
diff --git a/kernel/panic.c b/kernel/panic.c
index b6c482ccc5db..3efc6c1b85ca 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -27,13 +27,19 @@
#define PANIC_TIMER_STEP 100
#define PANIC_BLINK_SPD 18
+/* Machine specific panic information string */
+char *mach_panic_string;
+
int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE;
static unsigned long tainted_mask;
static int pause_on_oops;
static int pause_on_oops_flag;
static DEFINE_SPINLOCK(pause_on_oops_lock);
-int panic_timeout;
+#ifndef CONFIG_PANIC_TIMEOUT
+#define CONFIG_PANIC_TIMEOUT 0
+#endif
+int panic_timeout = CONFIG_PANIC_TIMEOUT;
EXPORT_SYMBOL_GPL(panic_timeout);
ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
@@ -380,6 +386,11 @@ late_initcall(init_oops_id);
void print_oops_end_marker(void)
{
init_oops_id();
+
+ if (mach_panic_string)
+ printk(KERN_WARNING "Board Information: %s\n",
+ mach_panic_string);
+
printk(KERN_WARNING "---[ end trace %016llx ]---\n",
(unsigned long long)oops_id);
}
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index d444c4e834f4..461af1caa235 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -18,6 +18,14 @@ config SUSPEND_FREEZER
Turning OFF this setting is NOT recommended! If in doubt, say Y.
+config HAS_WAKELOCK
+ bool
+ default y
+
+config WAKELOCK
+ bool
+ default y
+
config HIBERNATE_CALLBACKS
bool
@@ -293,3 +301,10 @@ config PM_GENERIC_DOMAINS_RUNTIME
config CPU_PM
bool
depends on SUSPEND || CPU_IDLE
+
+config SUSPEND_TIME
+ bool "Log time spent in suspend"
+ ---help---
+ Prints the time spent in suspend in the kernel log, and
+ keeps statistics on the time spent in suspend in
+ /sys/kernel/debug/suspend_time
diff --git a/kernel/power/Makefile b/kernel/power/Makefile
index 29472bff11ef..8450b85d33c0 100644
--- a/kernel/power/Makefile
+++ b/kernel/power/Makefile
@@ -11,5 +11,6 @@ obj-$(CONFIG_HIBERNATION) += hibernate.o snapshot.o swap.o user.o \
block_io.o
obj-$(CONFIG_PM_AUTOSLEEP) += autosleep.o
obj-$(CONFIG_PM_WAKELOCKS) += wakelock.o
+obj-$(CONFIG_SUSPEND_TIME) += suspend_time.o
obj-$(CONFIG_MAGIC_SYSRQ) += poweroff.o
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 62ee437b5c7e..4f1e813a2a58 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -25,6 +25,7 @@
#include <linux/suspend.h>
#include <linux/syscore_ops.h>
#include <linux/ftrace.h>
+#include <linux/rtc.h>
#include <trace/events/power.h>
#include "power.h"
@@ -358,6 +359,18 @@ static int enter_state(suspend_state_t state)
return error;
}
+static void pm_suspend_marker(char *annotation)
+{
+ struct timespec ts;
+ struct rtc_time tm;
+
+ getnstimeofday(&ts);
+ rtc_time_to_tm(ts.tv_sec, &tm);
+ pr_info("PM: suspend %s %d-%02d-%02d %02d:%02d:%02d.%09lu UTC\n",
+ annotation, tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
+ tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec);
+}
+
/**
* pm_suspend - Externally visible function for suspending the system.
* @state: System sleep state to enter.
@@ -372,6 +385,7 @@ int pm_suspend(suspend_state_t state)
if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
return -EINVAL;
+ pm_suspend_marker("entry");
error = enter_state(state);
if (error) {
suspend_stats.fail++;
@@ -379,6 +393,7 @@ int pm_suspend(suspend_state_t state)
} else {
suspend_stats.success++;
}
+ pm_suspend_marker("exit");
return error;
}
EXPORT_SYMBOL(pm_suspend);
diff --git a/kernel/power/suspend_time.c b/kernel/power/suspend_time.c
new file mode 100644
index 000000000000..d2a65da9f22c
--- /dev/null
+++ b/kernel/power/suspend_time.c
@@ -0,0 +1,111 @@
+/*
+ * debugfs file to track time spent in suspend
+ *
+ * Copyright (c) 2011, Google, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/seq_file.h>
+#include <linux/syscore_ops.h>
+#include <linux/time.h>
+
+static struct timespec suspend_time_before;
+static unsigned int time_in_suspend_bins[32];
+
+#ifdef CONFIG_DEBUG_FS
+static int suspend_time_debug_show(struct seq_file *s, void *data)
+{
+ int bin;
+ seq_printf(s, "time (secs) count\n");
+ seq_printf(s, "------------------\n");
+ for (bin = 0; bin < 32; bin++) {
+ if (time_in_suspend_bins[bin] == 0)
+ continue;
+ seq_printf(s, "%4d - %4d %4u\n",
+ bin ? 1 << (bin - 1) : 0, 1 << bin,
+ time_in_suspend_bins[bin]);
+ }
+ return 0;
+}
+
+static int suspend_time_debug_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, suspend_time_debug_show, NULL);
+}
+
+static const struct file_operations suspend_time_debug_fops = {
+ .open = suspend_time_debug_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int __init suspend_time_debug_init(void)
+{
+ struct dentry *d;
+
+ d = debugfs_create_file("suspend_time", 0755, NULL, NULL,
+ &suspend_time_debug_fops);
+ if (!d) {
+ pr_err("Failed to create suspend_time debug file\n");
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+late_initcall(suspend_time_debug_init);
+#endif
+
+static int suspend_time_syscore_suspend(void)
+{
+ read_persistent_clock(&suspend_time_before);
+
+ return 0;
+}
+
+static void suspend_time_syscore_resume(void)
+{
+ struct timespec after;
+
+ read_persistent_clock(&after);
+
+ after = timespec_sub(after, suspend_time_before);
+
+ time_in_suspend_bins[fls(after.tv_sec)]++;
+
+ pr_info("Suspended for %lu.%03lu seconds\n", after.tv_sec,
+ after.tv_nsec / NSEC_PER_MSEC);
+}
+
+static struct syscore_ops suspend_time_syscore_ops = {
+ .suspend = suspend_time_syscore_suspend,
+ .resume = suspend_time_syscore_resume,
+};
+
+static int suspend_time_syscore_init(void)
+{
+ register_syscore_ops(&suspend_time_syscore_ops);
+
+ return 0;
+}
+
+static void suspend_time_syscore_exit(void)
+{
+ unregister_syscore_ops(&suspend_time_syscore_ops);
+}
+module_init(suspend_time_syscore_init);
+module_exit(suspend_time_syscore_exit);
diff --git a/kernel/printk.c b/kernel/printk.c
new file mode 100644
index 000000000000..8212c1aef125
--- /dev/null
+++ b/kernel/printk.c
@@ -0,0 +1,2924 @@
+/*
+ * linux/kernel/printk.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * Modified to make sys_syslog() more flexible: added commands to
+ * return the last 4k of kernel messages, regardless of whether
+ * they've been read or not. Added option to suppress kernel printk's
+ * to the console. Added hook for sending the console messages
+ * elsewhere, in preparation for a serial line console (someday).
+ * Ted Ts'o, 2/11/93.
+ * Modified for sysctl support, 1/8/97, Chris Horn.
+ * Fixed SMP synchronization, 08/08/99, Manfred Spraul
+ * manfred@colorfullife.com
+ * Rewrote bits to get rid of console_lock
+ * 01Mar01 Andrew Morton
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/nmi.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/interrupt.h> /* For in_interrupt() */
+#include <linux/delay.h>
+#include <linux/smp.h>
+#include <linux/security.h>
+#include <linux/bootmem.h>
+#include <linux/memblock.h>
+#include <linux/aio.h>
+#include <linux/syscalls.h>
+#include <linux/kexec.h>
+#include <linux/kdb.h>
+#include <linux/ratelimit.h>
+#include <linux/kmsg_dump.h>
+#include <linux/syslog.h>
+#include <linux/cpu.h>
+#include <linux/notifier.h>
+#include <linux/rculist.h>
+#include <linux/poll.h>
+#include <linux/irq_work.h>
+#include <linux/utsname.h>
+
+#include <asm/uaccess.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/printk.h>
+
+/* printk's without a loglevel use this.. */
+#define DEFAULT_MESSAGE_LOGLEVEL CONFIG_DEFAULT_MESSAGE_LOGLEVEL
+
+/* We show everything that is MORE important than this.. */
+#define MINIMUM_CONSOLE_LOGLEVEL 1 /* Minimum loglevel we let people use */
+#define DEFAULT_CONSOLE_LOGLEVEL 7 /* anything MORE serious than KERN_DEBUG */
+
+int console_printk[4] = {
+ DEFAULT_CONSOLE_LOGLEVEL, /* console_loglevel */
+ DEFAULT_MESSAGE_LOGLEVEL, /* default_message_loglevel */
+ MINIMUM_CONSOLE_LOGLEVEL, /* minimum_console_loglevel */
+ DEFAULT_CONSOLE_LOGLEVEL, /* default_console_loglevel */
+};
+
+/*
+ * Low level drivers may need that to know if they can schedule in
+ * their unblank() callback or not. So let's export it.
+ */
+int oops_in_progress;
+EXPORT_SYMBOL(oops_in_progress);
+
+/*
+ * console_sem protects the console_drivers list, and also
+ * provides serialisation for access to the entire console
+ * driver system.
+ */
+static DEFINE_SEMAPHORE(console_sem);
+struct console *console_drivers;
+EXPORT_SYMBOL_GPL(console_drivers);
+
+#ifdef CONFIG_LOCKDEP
+static struct lockdep_map console_lock_dep_map = {
+ .name = "console_lock"
+};
+#endif
+
+/*
+ * This is used for debugging the mess that is the VT code by
+ * keeping track if we have the console semaphore held. It's
+ * definitely not the perfect debug tool (we don't know if _WE_
+ * hold it are racing, but it helps tracking those weird code
+ * path in the console code where we end up in places I want
+ * locked without the console sempahore held
+ */
+static int console_locked, console_suspended;
+
+/*
+ * If exclusive_console is non-NULL then only this console is to be printed to.
+ */
+static struct console *exclusive_console;
+
+/*
+ * Array of consoles built from command line options (console=)
+ */
+struct console_cmdline
+{
+ char name[8]; /* Name of the driver */
+ int index; /* Minor dev. to use */
+ char *options; /* Options for the driver */
+#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
+ char *brl_options; /* Options for braille driver */
+#endif
+};
+
+#define MAX_CMDLINECONSOLES 8
+
+static struct console_cmdline console_cmdline[MAX_CMDLINECONSOLES];
+static int selected_console = -1;
+static int preferred_console = -1;
+int console_set_on_cmdline;
+EXPORT_SYMBOL(console_set_on_cmdline);
+
+/* Flag: console code may call schedule() */
+static int console_may_schedule;
+
+/*
+ * The printk log buffer consists of a chain of concatenated variable
+ * length records. Every record starts with a record header, containing
+ * the overall length of the record.
+ *
+ * The heads to the first and last entry in the buffer, as well as the
+ * sequence numbers of these both entries are maintained when messages
+ * are stored..
+ *
+ * If the heads indicate available messages, the length in the header
+ * tells the start next message. A length == 0 for the next message
+ * indicates a wrap-around to the beginning of the buffer.
+ *
+ * Every record carries the monotonic timestamp in microseconds, as well as
+ * the standard userspace syslog level and syslog facility. The usual
+ * kernel messages use LOG_KERN; userspace-injected messages always carry
+ * a matching syslog facility, by default LOG_USER. The origin of every
+ * message can be reliably determined that way.
+ *
+ * The human readable log message directly follows the message header. The
+ * length of the message text is stored in the header, the stored message
+ * is not terminated.
+ *
+ * Optionally, a message can carry a dictionary of properties (key/value pairs),
+ * to provide userspace with a machine-readable message context.
+ *
+ * Examples for well-defined, commonly used property names are:
+ * DEVICE=b12:8 device identifier
+ * b12:8 block dev_t
+ * c127:3 char dev_t
+ * n8 netdev ifindex
+ * +sound:card0 subsystem:devname
+ * SUBSYSTEM=pci driver-core subsystem name
+ *
+ * Valid characters in property names are [a-zA-Z0-9.-_]. The plain text value
+ * follows directly after a '=' character. Every property is terminated by
+ * a '\0' character. The last property is not terminated.
+ *
+ * Example of a message structure:
+ * 0000 ff 8f 00 00 00 00 00 00 monotonic time in nsec
+ * 0008 34 00 record is 52 bytes long
+ * 000a 0b 00 text is 11 bytes long
+ * 000c 1f 00 dictionary is 23 bytes long
+ * 000e 03 00 LOG_KERN (facility) LOG_ERR (level)
+ * 0010 69 74 27 73 20 61 20 6c "it's a l"
+ * 69 6e 65 "ine"
+ * 001b 44 45 56 49 43 "DEVIC"
+ * 45 3d 62 38 3a 32 00 44 "E=b8:2\0D"
+ * 52 49 56 45 52 3d 62 75 "RIVER=bu"
+ * 67 "g"
+ * 0032 00 00 00 padding to next message header
+ *
+ * The 'struct log' buffer header must never be directly exported to
+ * userspace, it is a kernel-private implementation detail that might
+ * need to be changed in the future, when the requirements change.
+ *
+ * /dev/kmsg exports the structured data in the following line format:
+ * "level,sequnum,timestamp;<message text>\n"
+ *
+ * The optional key/value pairs are attached as continuation lines starting
+ * with a space character and terminated by a newline. All possible
+ * non-prinatable characters are escaped in the "\xff" notation.
+ *
+ * Users of the export format should ignore possible additional values
+ * separated by ',', and find the message after the ';' character.
+ */
+
+enum log_flags {
+ LOG_NOCONS = 1, /* already flushed, do not print to console */
+ LOG_NEWLINE = 2, /* text ended with a newline */
+ LOG_PREFIX = 4, /* text started with a prefix */
+ LOG_CONT = 8, /* text is a fragment of a continuation line */
+};
+
+struct log {
+ u64 ts_nsec; /* timestamp in nanoseconds */
+ u16 len; /* length of entire record */
+ u16 text_len; /* length of text buffer */
+ u16 dict_len; /* length of dictionary buffer */
+ u8 facility; /* syslog facility */
+ u8 flags:5; /* internal record flags */
+ u8 level:3; /* syslog level */
+};
+
+/*
+ * The logbuf_lock protects kmsg buffer, indices, counters. It is also
+ * used in interesting ways to provide interlocking in console_unlock();
+ */
+static DEFINE_RAW_SPINLOCK(logbuf_lock);
+
+#ifdef CONFIG_PRINTK
+DECLARE_WAIT_QUEUE_HEAD(log_wait);
+/* the next printk record to read by syslog(READ) or /proc/kmsg */
+static u64 syslog_seq;
+static u32 syslog_idx;
+static enum log_flags syslog_prev;
+static size_t syslog_partial;
+
+/* index and sequence number of the first record stored in the buffer */
+static u64 log_first_seq;
+static u32 log_first_idx;
+
+/* index and sequence number of the next record to store in the buffer */
+static u64 log_next_seq;
+static u32 log_next_idx;
+
+/* the next printk record to write to the console */
+static u64 console_seq;
+static u32 console_idx;
+static enum log_flags console_prev;
+
+/* the next printk record to read after the last 'clear' command */
+static u64 clear_seq;
+static u32 clear_idx;
+
+#define PREFIX_MAX 32
+#define LOG_LINE_MAX 1024 - PREFIX_MAX
+
+/* record buffer */
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
+#define LOG_ALIGN 4
+#else
+#define LOG_ALIGN __alignof__(struct log)
+#endif
+#define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
+static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN);
+static char *log_buf = __log_buf;
+static u32 log_buf_len = __LOG_BUF_LEN;
+
+/* cpu currently holding logbuf_lock */
+static volatile unsigned int logbuf_cpu = UINT_MAX;
+
+/* human readable text of the record */
+static char *log_text(const struct log *msg)
+{
+ return (char *)msg + sizeof(struct log);
+}
+
+/* optional key/value pair dictionary attached to the record */
+static char *log_dict(const struct log *msg)
+{
+ return (char *)msg + sizeof(struct log) + msg->text_len;
+}
+
+/* get record by index; idx must point to valid msg */
+static struct log *log_from_idx(u32 idx)
+{
+ struct log *msg = (struct log *)(log_buf + idx);
+
+ /*
+ * A length == 0 record is the end of buffer marker. Wrap around and
+ * read the message at the start of the buffer.
+ */
+ if (!msg->len)
+ return (struct log *)log_buf;
+ return msg;
+}
+
+/* get next record; idx must point to valid msg */
+static u32 log_next(u32 idx)
+{
+ struct log *msg = (struct log *)(log_buf + idx);
+
+ /* length == 0 indicates the end of the buffer; wrap */
+ /*
+ * A length == 0 record is the end of buffer marker. Wrap around and
+ * read the message at the start of the buffer as *this* one, and
+ * return the one after that.
+ */
+ if (!msg->len) {
+ msg = (struct log *)log_buf;
+ return msg->len;
+ }
+ return idx + msg->len;
+}
+
+/* insert record into the buffer, discard old ones, update heads */
+static void log_store(int facility, int level,
+ enum log_flags flags, u64 ts_nsec,
+ const char *dict, u16 dict_len,
+ const char *text, u16 text_len)
+{
+ struct log *msg;
+ u32 size, pad_len;
+
+ /* number of '\0' padding bytes to next message */
+ size = sizeof(struct log) + text_len + dict_len;
+ pad_len = (-size) & (LOG_ALIGN - 1);
+ size += pad_len;
+
+ while (log_first_seq < log_next_seq) {
+ u32 free;
+
+ if (log_next_idx > log_first_idx)
+ free = max(log_buf_len - log_next_idx, log_first_idx);
+ else
+ free = log_first_idx - log_next_idx;
+
+ if (free > size + sizeof(struct log))
+ break;
+
+ /* drop old messages until we have enough contiuous space */
+ log_first_idx = log_next(log_first_idx);
+ log_first_seq++;
+ }
+
+ if (log_next_idx + size + sizeof(struct log) >= log_buf_len) {
+ /*
+ * This message + an additional empty header does not fit
+ * at the end of the buffer. Add an empty header with len == 0
+ * to signify a wrap around.
+ */
+ memset(log_buf + log_next_idx, 0, sizeof(struct log));
+ log_next_idx = 0;
+ }
+
+ /* fill message */
+ msg = (struct log *)(log_buf + log_next_idx);
+ memcpy(log_text(msg), text, text_len);
+ msg->text_len = text_len;
+ memcpy(log_dict(msg), dict, dict_len);
+ msg->dict_len = dict_len;
+ msg->facility = facility;
+ msg->level = level & 7;
+ msg->flags = flags & 0x1f;
+ if (ts_nsec > 0)
+ msg->ts_nsec = ts_nsec;
+ else
+ msg->ts_nsec = local_clock();
+ memset(log_dict(msg) + dict_len, 0, pad_len);
+ msg->len = sizeof(struct log) + text_len + dict_len + pad_len;
+
+ /* insert message */
+ log_next_idx += msg->len;
+ log_next_seq++;
+}
+
+#ifdef CONFIG_SECURITY_DMESG_RESTRICT
+int dmesg_restrict = 1;
+#else
+int dmesg_restrict;
+#endif
+
+static int syslog_action_restricted(int type)
+{
+ if (dmesg_restrict)
+ return 1;
+ /*
+ * Unless restricted, we allow "read all" and "get buffer size"
+ * for everybody.
+ */
+ return type != SYSLOG_ACTION_READ_ALL &&
+ type != SYSLOG_ACTION_SIZE_BUFFER;
+}
+
+static int check_syslog_permissions(int type, bool from_file)
+{
+ /*
+ * If this is from /proc/kmsg and we've already opened it, then we've
+ * already done the capabilities checks at open time.
+ */
+ if (from_file && type != SYSLOG_ACTION_OPEN)
+ return 0;
+
+ if (syslog_action_restricted(type)) {
+ if (capable(CAP_SYSLOG))
+ return 0;
+ /*
+ * For historical reasons, accept CAP_SYS_ADMIN too, with
+ * a warning.
+ */
+ if (capable(CAP_SYS_ADMIN)) {
+ pr_warn_once("%s (%d): Attempt to access syslog with "
+ "CAP_SYS_ADMIN but no CAP_SYSLOG "
+ "(deprecated).\n",
+ current->comm, task_pid_nr(current));
+ return 0;
+ }
+ return -EPERM;
+ }
+ return security_syslog(type);
+}
+
+
+/* /dev/kmsg - userspace message inject/listen interface */
+struct devkmsg_user {
+ u64 seq;
+ u32 idx;
+ enum log_flags prev;
+ struct mutex lock;
+ char buf[8192];
+};
+
+static ssize_t devkmsg_writev(struct kiocb *iocb, const struct iovec *iv,
+ unsigned long count, loff_t pos)
+{
+ char *buf, *line;
+ int i;
+ int level = default_message_loglevel;
+ int facility = 1; /* LOG_USER */
+ size_t len = iov_length(iv, count);
+ ssize_t ret = len;
+
+ if (len > LOG_LINE_MAX)
+ return -EINVAL;
+ buf = kmalloc(len+1, GFP_KERNEL);
+ if (buf == NULL)
+ return -ENOMEM;
+
+ line = buf;
+ for (i = 0; i < count; i++) {
+ if (copy_from_user(line, iv[i].iov_base, iv[i].iov_len)) {
+ ret = -EFAULT;
+ goto out;
+ }
+ line += iv[i].iov_len;
+ }
+
+ /*
+ * Extract and skip the syslog prefix <[0-9]*>. Coming from userspace
+ * the decimal value represents 32bit, the lower 3 bit are the log
+ * level, the rest are the log facility.
+ *
+ * If no prefix or no userspace facility is specified, we
+ * enforce LOG_USER, to be able to reliably distinguish
+ * kernel-generated messages from userspace-injected ones.
+ */
+ line = buf;
+ if (line[0] == '<') {
+ char *endp = NULL;
+
+ i = simple_strtoul(line+1, &endp, 10);
+ if (endp && endp[0] == '>') {
+ level = i & 7;
+ if (i >> 3)
+ facility = i >> 3;
+ endp++;
+ len -= endp - line;
+ line = endp;
+ }
+ }
+ line[len] = '\0';
+
+ printk_emit(facility, level, NULL, 0, "%s", line);
+out:
+ kfree(buf);
+ return ret;
+}
+
+static ssize_t devkmsg_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct devkmsg_user *user = file->private_data;
+ struct log *msg;
+ u64 ts_usec;
+ size_t i;
+ char cont = '-';
+ size_t len;
+ ssize_t ret;
+
+ if (!user)
+ return -EBADF;
+
+ ret = mutex_lock_interruptible(&user->lock);
+ if (ret)
+ return ret;
+ raw_spin_lock_irq(&logbuf_lock);
+ while (user->seq == log_next_seq) {
+ if (file->f_flags & O_NONBLOCK) {
+ ret = -EAGAIN;
+ raw_spin_unlock_irq(&logbuf_lock);
+ goto out;
+ }
+
+ raw_spin_unlock_irq(&logbuf_lock);
+ ret = wait_event_interruptible(log_wait,
+ user->seq != log_next_seq);
+ if (ret)
+ goto out;
+ raw_spin_lock_irq(&logbuf_lock);
+ }
+
+ if (user->seq < log_first_seq) {
+ /* our last seen message is gone, return error and reset */
+ user->idx = log_first_idx;
+ user->seq = log_first_seq;
+ ret = -EPIPE;
+ raw_spin_unlock_irq(&logbuf_lock);
+ goto out;
+ }
+
+ msg = log_from_idx(user->idx);
+ ts_usec = msg->ts_nsec;
+ do_div(ts_usec, 1000);
+
+ /*
+ * If we couldn't merge continuation line fragments during the print,
+ * export the stored flags to allow an optional external merge of the
+ * records. Merging the records isn't always neccessarily correct, like
+ * when we hit a race during printing. In most cases though, it produces
+ * better readable output. 'c' in the record flags mark the first
+ * fragment of a line, '+' the following.
+ */
+ if (msg->flags & LOG_CONT && !(user->prev & LOG_CONT))
+ cont = 'c';
+ else if ((msg->flags & LOG_CONT) ||
+ ((user->prev & LOG_CONT) && !(msg->flags & LOG_PREFIX)))
+ cont = '+';
+
+ len = sprintf(user->buf, "%u,%llu,%llu,%c;",
+ (msg->facility << 3) | msg->level,
+ user->seq, ts_usec, cont);
+ user->prev = msg->flags;
+
+ /* escape non-printable characters */
+ for (i = 0; i < msg->text_len; i++) {
+ unsigned char c = log_text(msg)[i];
+
+ if (c < ' ' || c >= 127 || c == '\\')
+ len += sprintf(user->buf + len, "\\x%02x", c);
+ else
+ user->buf[len++] = c;
+ }
+ user->buf[len++] = '\n';
+
+ if (msg->dict_len) {
+ bool line = true;
+
+ for (i = 0; i < msg->dict_len; i++) {
+ unsigned char c = log_dict(msg)[i];
+
+ if (line) {
+ user->buf[len++] = ' ';
+ line = false;
+ }
+
+ if (c == '\0') {
+ user->buf[len++] = '\n';
+ line = true;
+ continue;
+ }
+
+ if (c < ' ' || c >= 127 || c == '\\') {
+ len += sprintf(user->buf + len, "\\x%02x", c);
+ continue;
+ }
+
+ user->buf[len++] = c;
+ }
+ user->buf[len++] = '\n';
+ }
+
+ user->idx = log_next(user->idx);
+ user->seq++;
+ raw_spin_unlock_irq(&logbuf_lock);
+
+ if (len > count) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (copy_to_user(buf, user->buf, len)) {
+ ret = -EFAULT;
+ goto out;
+ }
+ ret = len;
+out:
+ mutex_unlock(&user->lock);
+ return ret;
+}
+
+static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence)
+{
+ struct devkmsg_user *user = file->private_data;
+ loff_t ret = 0;
+
+ if (!user)
+ return -EBADF;
+ if (offset)
+ return -ESPIPE;
+
+ raw_spin_lock_irq(&logbuf_lock);
+ switch (whence) {
+ case SEEK_SET:
+ /* the first record */
+ user->idx = log_first_idx;
+ user->seq = log_first_seq;
+ break;
+ case SEEK_DATA:
+ /*
+ * The first record after the last SYSLOG_ACTION_CLEAR,
+ * like issued by 'dmesg -c'. Reading /dev/kmsg itself
+ * changes no global state, and does not clear anything.
+ */
+ user->idx = clear_idx;
+ user->seq = clear_seq;
+ break;
+ case SEEK_END:
+ /* after the last record */
+ user->idx = log_next_idx;
+ user->seq = log_next_seq;
+ break;
+ default:
+ ret = -EINVAL;
+ }
+ raw_spin_unlock_irq(&logbuf_lock);
+ return ret;
+}
+
+static unsigned int devkmsg_poll(struct file *file, poll_table *wait)
+{
+ struct devkmsg_user *user = file->private_data;
+ int ret = 0;
+
+ if (!user)
+ return POLLERR|POLLNVAL;
+
+ poll_wait(file, &log_wait, wait);
+
+ raw_spin_lock_irq(&logbuf_lock);
+ if (user->seq < log_next_seq) {
+ /* return error when data has vanished underneath us */
+ if (user->seq < log_first_seq)
+ ret = POLLIN|POLLRDNORM|POLLERR|POLLPRI;
+ else
+ ret = POLLIN|POLLRDNORM;
+ }
+ raw_spin_unlock_irq(&logbuf_lock);
+
+ return ret;
+}
+
+static int devkmsg_open(struct inode *inode, struct file *file)
+{
+ struct devkmsg_user *user;
+ int err;
+
+ /* write-only does not need any file context */
+ if ((file->f_flags & O_ACCMODE) == O_WRONLY)
+ return 0;
+
+ err = check_syslog_permissions(SYSLOG_ACTION_READ_ALL,
+ SYSLOG_FROM_READER);
+ if (err)
+ return err;
+
+ user = kmalloc(sizeof(struct devkmsg_user), GFP_KERNEL);
+ if (!user)
+ return -ENOMEM;
+
+ mutex_init(&user->lock);
+
+ raw_spin_lock_irq(&logbuf_lock);
+ user->idx = log_first_idx;
+ user->seq = log_first_seq;
+ raw_spin_unlock_irq(&logbuf_lock);
+
+ file->private_data = user;
+ return 0;
+}
+
+static int devkmsg_release(struct inode *inode, struct file *file)
+{
+ struct devkmsg_user *user = file->private_data;
+
+ if (!user)
+ return 0;
+
+ mutex_destroy(&user->lock);
+ kfree(user);
+ return 0;
+}
+
+const struct file_operations kmsg_fops = {
+ .open = devkmsg_open,
+ .read = devkmsg_read,
+ .aio_write = devkmsg_writev,
+ .llseek = devkmsg_llseek,
+ .poll = devkmsg_poll,
+ .release = devkmsg_release,
+};
+
+#ifdef CONFIG_KEXEC
+/*
+ * This appends the listed symbols to /proc/vmcoreinfo
+ *
+ * /proc/vmcoreinfo is used by various utiilties, like crash and makedumpfile to
+ * obtain access to symbols that are otherwise very difficult to locate. These
+ * symbols are specifically used so that utilities can access and extract the
+ * dmesg log from a vmcore file after a crash.
+ */
+void log_buf_kexec_setup(void)
+{
+ VMCOREINFO_SYMBOL(log_buf);
+ VMCOREINFO_SYMBOL(log_buf_len);
+ VMCOREINFO_SYMBOL(log_first_idx);
+ VMCOREINFO_SYMBOL(log_next_idx);
+ /*
+ * Export struct log size and field offsets. User space tools can
+ * parse it and detect any changes to structure down the line.
+ */
+ VMCOREINFO_STRUCT_SIZE(log);
+ VMCOREINFO_OFFSET(log, ts_nsec);
+ VMCOREINFO_OFFSET(log, len);
+ VMCOREINFO_OFFSET(log, text_len);
+ VMCOREINFO_OFFSET(log, dict_len);
+}
+#endif
+
+/* requested log_buf_len from kernel cmdline */
+static unsigned long __initdata new_log_buf_len;
+
+/* save requested log_buf_len since it's too early to process it */
+static int __init log_buf_len_setup(char *str)
+{
+ unsigned size = memparse(str, &str);
+
+ if (size)
+ size = roundup_pow_of_two(size);
+ if (size > log_buf_len)
+ new_log_buf_len = size;
+
+ return 0;
+}
+early_param("log_buf_len", log_buf_len_setup);
+
+void __init setup_log_buf(int early)
+{
+ unsigned long flags;
+ char *new_log_buf;
+ int free;
+
+ if (!new_log_buf_len)
+ return;
+
+ if (early) {
+ unsigned long mem;
+
+ mem = memblock_alloc(new_log_buf_len, PAGE_SIZE);
+ if (!mem)
+ return;
+ new_log_buf = __va(mem);
+ } else {
+ new_log_buf = alloc_bootmem_nopanic(new_log_buf_len);
+ }
+
+ if (unlikely(!new_log_buf)) {
+ pr_err("log_buf_len: %ld bytes not available\n",
+ new_log_buf_len);
+ return;
+ }
+
+ raw_spin_lock_irqsave(&logbuf_lock, flags);
+ log_buf_len = new_log_buf_len;
+ log_buf = new_log_buf;
+ new_log_buf_len = 0;
+ free = __LOG_BUF_LEN - log_next_idx;
+ memcpy(log_buf, __log_buf, __LOG_BUF_LEN);
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+
+ pr_info("log_buf_len: %d\n", log_buf_len);
+ pr_info("early log buf free: %d(%d%%)\n",
+ free, (free * 100) / __LOG_BUF_LEN);
+}
+
+static bool __read_mostly ignore_loglevel;
+
+static int __init ignore_loglevel_setup(char *str)
+{
+ ignore_loglevel = 1;
+ printk(KERN_INFO "debug: ignoring loglevel setting.\n");
+
+ return 0;
+}
+
+early_param("ignore_loglevel", ignore_loglevel_setup);
+module_param(ignore_loglevel, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(ignore_loglevel, "ignore loglevel setting, to"
+ "print all kernel messages to the console.");
+
+#ifdef CONFIG_BOOT_PRINTK_DELAY
+
+static int boot_delay; /* msecs delay after each printk during bootup */
+static unsigned long long loops_per_msec; /* based on boot_delay */
+
+static int __init boot_delay_setup(char *str)
+{
+ unsigned long lpj;
+
+ lpj = preset_lpj ? preset_lpj : 1000000; /* some guess */
+ loops_per_msec = (unsigned long long)lpj / 1000 * HZ;
+
+ get_option(&str, &boot_delay);
+ if (boot_delay > 10 * 1000)
+ boot_delay = 0;
+
+ pr_debug("boot_delay: %u, preset_lpj: %ld, lpj: %lu, "
+ "HZ: %d, loops_per_msec: %llu\n",
+ boot_delay, preset_lpj, lpj, HZ, loops_per_msec);
+ return 1;
+}
+__setup("boot_delay=", boot_delay_setup);
+
+static void boot_delay_msec(int level)
+{
+ unsigned long long k;
+ unsigned long timeout;
+
+ if ((boot_delay == 0 || system_state != SYSTEM_BOOTING)
+ || (level >= console_loglevel && !ignore_loglevel)) {
+ return;
+ }
+
+ k = (unsigned long long)loops_per_msec * boot_delay;
+
+ timeout = jiffies + msecs_to_jiffies(boot_delay);
+ while (k) {
+ k--;
+ cpu_relax();
+ /*
+ * use (volatile) jiffies to prevent
+ * compiler reduction; loop termination via jiffies
+ * is secondary and may or may not happen.
+ */
+ if (time_after(jiffies, timeout))
+ break;
+ touch_nmi_watchdog();
+ }
+}
+#else
+static inline void boot_delay_msec(int level)
+{
+}
+#endif
+
+#if defined(CONFIG_PRINTK_TIME)
+static bool printk_time = 1;
+#else
+static bool printk_time;
+#endif
+module_param_named(time, printk_time, bool, S_IRUGO | S_IWUSR);
+
+static size_t print_time(u64 ts, char *buf)
+{
+ unsigned long rem_nsec;
+
+ if (!printk_time)
+ return 0;
+
+ rem_nsec = do_div(ts, 1000000000);
+
+ if (!buf)
+ return snprintf(NULL, 0, "[%5lu.000000] ", (unsigned long)ts);
+
+ return sprintf(buf, "[%5lu.%06lu] ",
+ (unsigned long)ts, rem_nsec / 1000);
+}
+
+static size_t print_prefix(const struct log *msg, bool syslog, char *buf)
+{
+ size_t len = 0;
+ unsigned int prefix = (msg->facility << 3) | msg->level;
+
+ if (syslog) {
+ if (buf) {
+ len += sprintf(buf, "<%u>", prefix);
+ } else {
+ len += 3;
+ if (prefix > 999)
+ len += 3;
+ else if (prefix > 99)
+ len += 2;
+ else if (prefix > 9)
+ len++;
+ }
+ }
+
+ len += print_time(msg->ts_nsec, buf ? buf + len : NULL);
+ return len;
+}
+
+static size_t msg_print_text(const struct log *msg, enum log_flags prev,
+ bool syslog, char *buf, size_t size)
+{
+ const char *text = log_text(msg);
+ size_t text_size = msg->text_len;
+ bool prefix = true;
+ bool newline = true;
+ size_t len = 0;
+
+ if ((prev & LOG_CONT) && !(msg->flags & LOG_PREFIX))
+ prefix = false;
+
+ if (msg->flags & LOG_CONT) {
+ if ((prev & LOG_CONT) && !(prev & LOG_NEWLINE))
+ prefix = false;
+
+ if (!(msg->flags & LOG_NEWLINE))
+ newline = false;
+ }
+
+ do {
+ const char *next = memchr(text, '\n', text_size);
+ size_t text_len;
+
+ if (next) {
+ text_len = next - text;
+ next++;
+ text_size -= next - text;
+ } else {
+ text_len = text_size;
+ }
+
+ if (buf) {
+ if (print_prefix(msg, syslog, NULL) +
+ text_len + 1 >= size - len)
+ break;
+
+ if (prefix)
+ len += print_prefix(msg, syslog, buf + len);
+ memcpy(buf + len, text, text_len);
+ len += text_len;
+ if (next || newline)
+ buf[len++] = '\n';
+ } else {
+ /* SYSLOG_ACTION_* buffer size only calculation */
+ if (prefix)
+ len += print_prefix(msg, syslog, NULL);
+ len += text_len;
+ if (next || newline)
+ len++;
+ }
+
+ prefix = true;
+ text = next;
+ } while (text);
+
+ return len;
+}
+
+static int syslog_print(char __user *buf, int size)
+{
+ char *text;
+ struct log *msg;
+ int len = 0;
+
+ text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
+ if (!text)
+ return -ENOMEM;
+
+ while (size > 0) {
+ size_t n;
+ size_t skip;
+
+ raw_spin_lock_irq(&logbuf_lock);
+ if (syslog_seq < log_first_seq) {
+ /* messages are gone, move to first one */
+ syslog_seq = log_first_seq;
+ syslog_idx = log_first_idx;
+ syslog_prev = 0;
+ syslog_partial = 0;
+ }
+ if (syslog_seq == log_next_seq) {
+ raw_spin_unlock_irq(&logbuf_lock);
+ break;
+ }
+
+ skip = syslog_partial;
+ msg = log_from_idx(syslog_idx);
+ n = msg_print_text(msg, syslog_prev, true, text,
+ LOG_LINE_MAX + PREFIX_MAX);
+ if (n - syslog_partial <= size) {
+ /* message fits into buffer, move forward */
+ syslog_idx = log_next(syslog_idx);
+ syslog_seq++;
+ syslog_prev = msg->flags;
+ n -= syslog_partial;
+ syslog_partial = 0;
+ } else if (!len){
+ /* partial read(), remember position */
+ n = size;
+ syslog_partial += n;
+ } else
+ n = 0;
+ raw_spin_unlock_irq(&logbuf_lock);
+
+ if (!n)
+ break;
+
+ if (copy_to_user(buf, text + skip, n)) {
+ if (!len)
+ len = -EFAULT;
+ break;
+ }
+
+ len += n;
+ size -= n;
+ buf += n;
+ }
+
+ kfree(text);
+ return len;
+}
+
+static int syslog_print_all(char __user *buf, int size, bool clear)
+{
+ char *text;
+ int len = 0;
+
+ text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
+ if (!text)
+ return -ENOMEM;
+
+ raw_spin_lock_irq(&logbuf_lock);
+ if (buf) {
+ u64 next_seq;
+ u64 seq;
+ u32 idx;
+ enum log_flags prev;
+
+ if (clear_seq < log_first_seq) {
+ /* messages are gone, move to first available one */
+ clear_seq = log_first_seq;
+ clear_idx = log_first_idx;
+ }
+
+ /*
+ * Find first record that fits, including all following records,
+ * into the user-provided buffer for this dump.
+ */
+ seq = clear_seq;
+ idx = clear_idx;
+ prev = 0;
+ while (seq < log_next_seq) {
+ struct log *msg = log_from_idx(idx);
+
+ len += msg_print_text(msg, prev, true, NULL, 0);
+ prev = msg->flags;
+ idx = log_next(idx);
+ seq++;
+ }
+
+ /* move first record forward until length fits into the buffer */
+ seq = clear_seq;
+ idx = clear_idx;
+ prev = 0;
+ while (len > size && seq < log_next_seq) {
+ struct log *msg = log_from_idx(idx);
+
+ len -= msg_print_text(msg, prev, true, NULL, 0);
+ prev = msg->flags;
+ idx = log_next(idx);
+ seq++;
+ }
+
+ /* last message fitting into this dump */
+ next_seq = log_next_seq;
+
+ len = 0;
+ prev = 0;
+ while (len >= 0 && seq < next_seq) {
+ struct log *msg = log_from_idx(idx);
+ int textlen;
+
+ textlen = msg_print_text(msg, prev, true, text,
+ LOG_LINE_MAX + PREFIX_MAX);
+ if (textlen < 0) {
+ len = textlen;
+ break;
+ }
+ idx = log_next(idx);
+ seq++;
+ prev = msg->flags;
+
+ raw_spin_unlock_irq(&logbuf_lock);
+ if (copy_to_user(buf + len, text, textlen))
+ len = -EFAULT;
+ else
+ len += textlen;
+ raw_spin_lock_irq(&logbuf_lock);
+
+ if (seq < log_first_seq) {
+ /* messages are gone, move to next one */
+ seq = log_first_seq;
+ idx = log_first_idx;
+ prev = 0;
+ }
+ }
+ }
+
+ if (clear) {
+ clear_seq = log_next_seq;
+ clear_idx = log_next_idx;
+ }
+ raw_spin_unlock_irq(&logbuf_lock);
+
+ kfree(text);
+ return len;
+}
+
+int do_syslog(int type, char __user *buf, int len, bool from_file)
+{
+ bool clear = false;
+ static int saved_console_loglevel = -1;
+ int error;
+
+ error = check_syslog_permissions(type, from_file);
+ if (error)
+ goto out;
+
+ error = security_syslog(type);
+ if (error)
+ return error;
+
+ switch (type) {
+ case SYSLOG_ACTION_CLOSE: /* Close log */
+ break;
+ case SYSLOG_ACTION_OPEN: /* Open log */
+ break;
+ case SYSLOG_ACTION_READ: /* Read from log */
+ error = -EINVAL;
+ if (!buf || len < 0)
+ goto out;
+ error = 0;
+ if (!len)
+ goto out;
+ if (!access_ok(VERIFY_WRITE, buf, len)) {
+ error = -EFAULT;
+ goto out;
+ }
+ error = wait_event_interruptible(log_wait,
+ syslog_seq != log_next_seq);
+ if (error)
+ goto out;
+ error = syslog_print(buf, len);
+ break;
+ /* Read/clear last kernel messages */
+ case SYSLOG_ACTION_READ_CLEAR:
+ clear = true;
+ /* FALL THRU */
+ /* Read last kernel messages */
+ case SYSLOG_ACTION_READ_ALL:
+ error = -EINVAL;
+ if (!buf || len < 0)
+ goto out;
+ error = 0;
+ if (!len)
+ goto out;
+ if (!access_ok(VERIFY_WRITE, buf, len)) {
+ error = -EFAULT;
+ goto out;
+ }
+ error = syslog_print_all(buf, len, clear);
+ break;
+ /* Clear ring buffer */
+ case SYSLOG_ACTION_CLEAR:
+ syslog_print_all(NULL, 0, true);
+ break;
+ /* Disable logging to console */
+ case SYSLOG_ACTION_CONSOLE_OFF:
+ if (saved_console_loglevel == -1)
+ saved_console_loglevel = console_loglevel;
+ console_loglevel = minimum_console_loglevel;
+ break;
+ /* Enable logging to console */
+ case SYSLOG_ACTION_CONSOLE_ON:
+ if (saved_console_loglevel != -1) {
+ console_loglevel = saved_console_loglevel;
+ saved_console_loglevel = -1;
+ }
+ break;
+ /* Set level of messages printed to console */
+ case SYSLOG_ACTION_CONSOLE_LEVEL:
+ error = -EINVAL;
+ if (len < 1 || len > 8)
+ goto out;
+ if (len < minimum_console_loglevel)
+ len = minimum_console_loglevel;
+ console_loglevel = len;
+ /* Implicitly re-enable logging to console */
+ saved_console_loglevel = -1;
+ error = 0;
+ break;
+ /* Number of chars in the log buffer */
+ case SYSLOG_ACTION_SIZE_UNREAD:
+ raw_spin_lock_irq(&logbuf_lock);
+ if (syslog_seq < log_first_seq) {
+ /* messages are gone, move to first one */
+ syslog_seq = log_first_seq;
+ syslog_idx = log_first_idx;
+ syslog_prev = 0;
+ syslog_partial = 0;
+ }
+ if (from_file) {
+ /*
+ * Short-cut for poll(/"proc/kmsg") which simply checks
+ * for pending data, not the size; return the count of
+ * records, not the length.
+ */
+ error = log_next_idx - syslog_idx;
+ } else {
+ u64 seq = syslog_seq;
+ u32 idx = syslog_idx;
+ enum log_flags prev = syslog_prev;
+
+ error = 0;
+ while (seq < log_next_seq) {
+ struct log *msg = log_from_idx(idx);
+
+ error += msg_print_text(msg, prev, true, NULL, 0);
+ idx = log_next(idx);
+ seq++;
+ prev = msg->flags;
+ }
+ error -= syslog_partial;
+ }
+ raw_spin_unlock_irq(&logbuf_lock);
+ break;
+ /* Size of the log buffer */
+ case SYSLOG_ACTION_SIZE_BUFFER:
+ error = log_buf_len;
+ break;
+ default:
+ error = -EINVAL;
+ break;
+ }
+out:
+ return error;
+}
+
+SYSCALL_DEFINE3(syslog, int, type, char __user *, buf, int, len)
+{
+ return do_syslog(type, buf, len, SYSLOG_FROM_READER);
+}
+
+/*
+ * Call the console drivers, asking them to write out
+ * log_buf[start] to log_buf[end - 1].
+ * The console_lock must be held.
+ */
+static void call_console_drivers(int level, const char *text, size_t len)
+{
+ struct console *con;
+
+ trace_console(text, len);
+
+ if (level >= console_loglevel && !ignore_loglevel)
+ return;
+ if (!console_drivers)
+ return;
+
+ for_each_console(con) {
+ if (exclusive_console && con != exclusive_console)
+ continue;
+ if (!(con->flags & CON_ENABLED))
+ continue;
+ if (!con->write)
+ continue;
+ if (!cpu_online(smp_processor_id()) &&
+ !(con->flags & CON_ANYTIME))
+ continue;
+ con->write(con, text, len);
+ }
+}
+
+/*
+ * Zap console related locks when oopsing. Only zap at most once
+ * every 10 seconds, to leave time for slow consoles to print a
+ * full oops.
+ */
+static void zap_locks(void)
+{
+ static unsigned long oops_timestamp;
+
+ if (time_after_eq(jiffies, oops_timestamp) &&
+ !time_after(jiffies, oops_timestamp + 30 * HZ))
+ return;
+
+ oops_timestamp = jiffies;
+
+ debug_locks_off();
+ /* If a crash is occurring, make sure we can't deadlock */
+ raw_spin_lock_init(&logbuf_lock);
+ /* And make sure that we print immediately */
+ sema_init(&console_sem, 1);
+}
+
+/* Check if we have any console registered that can be called early in boot. */
+static int have_callable_console(void)
+{
+ struct console *con;
+
+ for_each_console(con)
+ if (con->flags & CON_ANYTIME)
+ return 1;
+
+ return 0;
+}
+
+/*
+ * Can we actually use the console at this time on this cpu?
+ *
+ * Console drivers may assume that per-cpu resources have
+ * been allocated. So unless they're explicitly marked as
+ * being able to cope (CON_ANYTIME) don't call them until
+ * this CPU is officially up.
+ */
+static inline int can_use_console(unsigned int cpu)
+{
+ return cpu_online(cpu) || have_callable_console();
+}
+
+/*
+ * Try to get console ownership to actually show the kernel
+ * messages from a 'printk'. Return true (and with the
+ * console_lock held, and 'console_locked' set) if it
+ * is successful, false otherwise.
+ *
+ * This gets called with the 'logbuf_lock' spinlock held and
+ * interrupts disabled. It should return with 'lockbuf_lock'
+ * released but interrupts still disabled.
+ */
+static int console_trylock_for_printk(unsigned int cpu)
+ __releases(&logbuf_lock)
+{
+ int retval = 0, wake = 0;
+
+ if (console_trylock()) {
+ retval = 1;
+
+ /*
+ * If we can't use the console, we need to release
+ * the console semaphore by hand to avoid flushing
+ * the buffer. We need to hold the console semaphore
+ * in order to do this test safely.
+ */
+ if (!can_use_console(cpu)) {
+ console_locked = 0;
+ wake = 1;
+ retval = 0;
+ }
+ }
+ logbuf_cpu = UINT_MAX;
+ if (wake)
+ up(&console_sem);
+ raw_spin_unlock(&logbuf_lock);
+ return retval;
+}
+
+int printk_delay_msec __read_mostly;
+
+static inline void printk_delay(void)
+{
+ if (unlikely(printk_delay_msec)) {
+ int m = printk_delay_msec;
+
+ while (m--) {
+ mdelay(1);
+ touch_nmi_watchdog();
+ }
+ }
+}
+
+/*
+ * Continuation lines are buffered, and not committed to the record buffer
+ * until the line is complete, or a race forces it. The line fragments
+ * though, are printed immediately to the consoles to ensure everything has
+ * reached the console in case of a kernel crash.
+ */
+static struct cont {
+ char buf[LOG_LINE_MAX];
+ size_t len; /* length == 0 means unused buffer */
+ size_t cons; /* bytes written to console */
+ struct task_struct *owner; /* task of first print*/
+ u64 ts_nsec; /* time of first print */
+ u8 level; /* log level of first message */
+ u8 facility; /* log level of first message */
+ enum log_flags flags; /* prefix, newline flags */
+ bool flushed:1; /* buffer sealed and committed */
+} cont;
+
+static void cont_flush(enum log_flags flags)
+{
+ if (cont.flushed)
+ return;
+ if (cont.len == 0)
+ return;
+
+ if (cont.cons) {
+ /*
+ * If a fragment of this line was directly flushed to the
+ * console; wait for the console to pick up the rest of the
+ * line. LOG_NOCONS suppresses a duplicated output.
+ */
+ log_store(cont.facility, cont.level, flags | LOG_NOCONS,
+ cont.ts_nsec, NULL, 0, cont.buf, cont.len);
+ cont.flags = flags;
+ cont.flushed = true;
+ } else {
+ /*
+ * If no fragment of this line ever reached the console,
+ * just submit it to the store and free the buffer.
+ */
+ log_store(cont.facility, cont.level, flags, 0,
+ NULL, 0, cont.buf, cont.len);
+ cont.len = 0;
+ }
+}
+
+static bool cont_add(int facility, int level, const char *text, size_t len)
+{
+ if (cont.len && cont.flushed)
+ return false;
+
+ if (cont.len + len > sizeof(cont.buf)) {
+ /* the line gets too long, split it up in separate records */
+ cont_flush(LOG_CONT);
+ return false;
+ }
+
+ if (!cont.len) {
+ cont.facility = facility;
+ cont.level = level;
+ cont.owner = current;
+ cont.ts_nsec = local_clock();
+ cont.flags = 0;
+ cont.cons = 0;
+ cont.flushed = false;
+ }
+
+ memcpy(cont.buf + cont.len, text, len);
+ cont.len += len;
+
+ if (cont.len > (sizeof(cont.buf) * 80) / 100)
+ cont_flush(LOG_CONT);
+
+ return true;
+}
+
+static size_t cont_print_text(char *text, size_t size)
+{
+ size_t textlen = 0;
+ size_t len;
+
+ if (cont.cons == 0 && (console_prev & LOG_NEWLINE)) {
+ textlen += print_time(cont.ts_nsec, text);
+ size -= textlen;
+ }
+
+ len = cont.len - cont.cons;
+ if (len > 0) {
+ if (len+1 > size)
+ len = size-1;
+ memcpy(text + textlen, cont.buf + cont.cons, len);
+ textlen += len;
+ cont.cons = cont.len;
+ }
+
+ if (cont.flushed) {
+ if (cont.flags & LOG_NEWLINE)
+ text[textlen++] = '\n';
+ /* got everything, release buffer */
+ cont.len = 0;
+ }
+ return textlen;
+}
+
+asmlinkage int vprintk_emit(int facility, int level,
+ const char *dict, size_t dictlen,
+ const char *fmt, va_list args)
+{
+ static int recursion_bug;
+ static char textbuf[LOG_LINE_MAX];
+ char *text = textbuf;
+ size_t text_len;
+ enum log_flags lflags = 0;
+ unsigned long flags;
+ int this_cpu;
+ int printed_len = 0;
+
+ boot_delay_msec(level);
+ printk_delay();
+
+ /* This stops the holder of console_sem just where we want him */
+ local_irq_save(flags);
+ this_cpu = smp_processor_id();
+
+ /*
+ * Ouch, printk recursed into itself!
+ */
+ if (unlikely(logbuf_cpu == this_cpu)) {
+ /*
+ * If a crash is occurring during printk() on this CPU,
+ * then try to get the crash message out but make sure
+ * we can't deadlock. Otherwise just return to avoid the
+ * recursion and return - but flag the recursion so that
+ * it can be printed at the next appropriate moment:
+ */
+ if (!oops_in_progress && !lockdep_recursing(current)) {
+ recursion_bug = 1;
+ goto out_restore_irqs;
+ }
+ zap_locks();
+ }
+
+ lockdep_off();
+ raw_spin_lock(&logbuf_lock);
+ logbuf_cpu = this_cpu;
+
+ if (recursion_bug) {
+ static const char recursion_msg[] =
+ "BUG: recent printk recursion!";
+
+ recursion_bug = 0;
+ printed_len += strlen(recursion_msg);
+ /* emit KERN_CRIT message */
+ log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0,
+ NULL, 0, recursion_msg, printed_len);
+ }
+
+ /*
+ * The printf needs to come first; we need the syslog
+ * prefix which might be passed-in as a parameter.
+ */
+ text_len = vscnprintf(text, sizeof(textbuf), fmt, args);
+
+ /* mark and strip a trailing newline */
+ if (text_len && text[text_len-1] == '\n') {
+ text_len--;
+ lflags |= LOG_NEWLINE;
+ }
+
+ /* strip kernel syslog prefix and extract log level or control flags */
+ if (facility == 0) {
+ int kern_level = printk_get_level(text);
+
+ if (kern_level) {
+ const char *end_of_header = printk_skip_level(text);
+ switch (kern_level) {
+ case '0' ... '7':
+ if (level == -1)
+ level = kern_level - '0';
+ case 'd': /* KERN_DEFAULT */
+ lflags |= LOG_PREFIX;
+ case 'c': /* KERN_CONT */
+ break;
+ }
+ text_len -= end_of_header - text;
+ text = (char *)end_of_header;
+ }
+ }
+
+ if (level == -1)
+ level = default_message_loglevel;
+
+ if (dict)
+ lflags |= LOG_PREFIX|LOG_NEWLINE;
+
+ if (!(lflags & LOG_NEWLINE)) {
+ /*
+ * Flush the conflicting buffer. An earlier newline was missing,
+ * or another task also prints continuation lines.
+ */
+ if (cont.len && (lflags & LOG_PREFIX || cont.owner != current))
+ cont_flush(LOG_NEWLINE);
+
+ /* buffer line if possible, otherwise store it right away */
+ if (!cont_add(facility, level, text, text_len))
+ log_store(facility, level, lflags | LOG_CONT, 0,
+ dict, dictlen, text, text_len);
+ } else {
+ bool stored = false;
+
+ /*
+ * If an earlier newline was missing and it was the same task,
+ * either merge it with the current buffer and flush, or if
+ * there was a race with interrupts (prefix == true) then just
+ * flush it out and store this line separately.
+ */
+ if (cont.len && cont.owner == current) {
+ if (!(lflags & LOG_PREFIX))
+ stored = cont_add(facility, level, text, text_len);
+ cont_flush(LOG_NEWLINE);
+ }
+
+ if (!stored)
+ log_store(facility, level, lflags, 0,
+ dict, dictlen, text, text_len);
+ }
+ printed_len += text_len;
+
+ /*
+ * Try to acquire and then immediately release the console semaphore.
+ * The release will print out buffers and wake up /dev/kmsg and syslog()
+ * users.
+ *
+ * The console_trylock_for_printk() function will release 'logbuf_lock'
+ * regardless of whether it actually gets the console semaphore or not.
+ */
+ if (console_trylock_for_printk(this_cpu))
+ console_unlock();
+
+ lockdep_on();
+out_restore_irqs:
+ local_irq_restore(flags);
+
+ return printed_len;
+}
+EXPORT_SYMBOL(vprintk_emit);
+
+asmlinkage int vprintk(const char *fmt, va_list args)
+{
+ return vprintk_emit(0, -1, NULL, 0, fmt, args);
+}
+EXPORT_SYMBOL(vprintk);
+
+asmlinkage int printk_emit(int facility, int level,
+ const char *dict, size_t dictlen,
+ const char *fmt, ...)
+{
+ va_list args;
+ int r;
+
+ va_start(args, fmt);
+ r = vprintk_emit(facility, level, dict, dictlen, fmt, args);
+ va_end(args);
+
+ return r;
+}
+EXPORT_SYMBOL(printk_emit);
+
+/**
+ * printk - print a kernel message
+ * @fmt: format string
+ *
+ * This is printk(). It can be called from any context. We want it to work.
+ *
+ * We try to grab the console_lock. If we succeed, it's easy - we log the
+ * output and call the console drivers. If we fail to get the semaphore, we
+ * place the output into the log buffer and return. The current holder of
+ * the console_sem will notice the new output in console_unlock(); and will
+ * send it to the consoles before releasing the lock.
+ *
+ * One effect of this deferred printing is that code which calls printk() and
+ * then changes console_loglevel may break. This is because console_loglevel
+ * is inspected when the actual printing occurs.
+ *
+ * See also:
+ * printf(3)
+ *
+ * See the vsnprintf() documentation for format string extensions over C99.
+ */
+asmlinkage int printk(const char *fmt, ...)
+{
+ va_list args;
+ int r;
+
+#ifdef CONFIG_KGDB_KDB
+ if (unlikely(kdb_trap_printk)) {
+ va_start(args, fmt);
+ r = vkdb_printf(fmt, args);
+ va_end(args);
+ return r;
+ }
+#endif
+ va_start(args, fmt);
+ r = vprintk_emit(0, -1, NULL, 0, fmt, args);
+ va_end(args);
+
+ return r;
+}
+EXPORT_SYMBOL(printk);
+
+#else /* CONFIG_PRINTK */
+
+#define LOG_LINE_MAX 0
+#define PREFIX_MAX 0
+#define LOG_LINE_MAX 0
+static u64 syslog_seq;
+static u32 syslog_idx;
+static u64 console_seq;
+static u32 console_idx;
+static enum log_flags syslog_prev;
+static u64 log_first_seq;
+static u32 log_first_idx;
+static u64 log_next_seq;
+static enum log_flags console_prev;
+static struct cont {
+ size_t len;
+ size_t cons;
+ u8 level;
+ bool flushed:1;
+} cont;
+static struct log *log_from_idx(u32 idx) { return NULL; }
+static u32 log_next(u32 idx) { return 0; }
+static void call_console_drivers(int level, const char *text, size_t len) {}
+static size_t msg_print_text(const struct log *msg, enum log_flags prev,
+ bool syslog, char *buf, size_t size) { return 0; }
+static size_t cont_print_text(char *text, size_t size) { return 0; }
+
+#endif /* CONFIG_PRINTK */
+
+#ifdef CONFIG_EARLY_PRINTK
+struct console *early_console;
+
+void early_vprintk(const char *fmt, va_list ap)
+{
+ if (early_console) {
+ char buf[512];
+ int n = vscnprintf(buf, sizeof(buf), fmt, ap);
+
+ early_console->write(early_console, buf, n);
+ }
+}
+
+asmlinkage void early_printk(const char *fmt, ...)
+{
+ va_list ap;
+
+ va_start(ap, fmt);
+ early_vprintk(fmt, ap);
+ va_end(ap);
+}
+#endif
+
+static int __add_preferred_console(char *name, int idx, char *options,
+ char *brl_options)
+{
+ struct console_cmdline *c;
+ int i;
+
+ /*
+ * See if this tty is not yet registered, and
+ * if we have a slot free.
+ */
+ for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0]; i++)
+ if (strcmp(console_cmdline[i].name, name) == 0 &&
+ console_cmdline[i].index == idx) {
+ if (!brl_options)
+ selected_console = i;
+ return 0;
+ }
+ if (i == MAX_CMDLINECONSOLES)
+ return -E2BIG;
+ if (!brl_options)
+ selected_console = i;
+ c = &console_cmdline[i];
+ strlcpy(c->name, name, sizeof(c->name));
+ c->options = options;
+#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
+ c->brl_options = brl_options;
+#endif
+ c->index = idx;
+ return 0;
+}
+/*
+ * Set up a list of consoles. Called from init/main.c
+ */
+static int __init console_setup(char *str)
+{
+ char buf[sizeof(console_cmdline[0].name) + 4]; /* 4 for index */
+ char *s, *options, *brl_options = NULL;
+ int idx;
+
+#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
+ if (!memcmp(str, "brl,", 4)) {
+ brl_options = "";
+ str += 4;
+ } else if (!memcmp(str, "brl=", 4)) {
+ brl_options = str + 4;
+ str = strchr(brl_options, ',');
+ if (!str) {
+ printk(KERN_ERR "need port name after brl=\n");
+ return 1;
+ }
+ *(str++) = 0;
+ }
+#endif
+
+ /*
+ * Decode str into name, index, options.
+ */
+ if (str[0] >= '0' && str[0] <= '9') {
+ strcpy(buf, "ttyS");
+ strncpy(buf + 4, str, sizeof(buf) - 5);
+ } else {
+ strncpy(buf, str, sizeof(buf) - 1);
+ }
+ buf[sizeof(buf) - 1] = 0;
+ if ((options = strchr(str, ',')) != NULL)
+ *(options++) = 0;
+#ifdef __sparc__
+ if (!strcmp(str, "ttya"))
+ strcpy(buf, "ttyS0");
+ if (!strcmp(str, "ttyb"))
+ strcpy(buf, "ttyS1");
+#endif
+ for (s = buf; *s; s++)
+ if ((*s >= '0' && *s <= '9') || *s == ',')
+ break;
+ idx = simple_strtoul(s, NULL, 10);
+ *s = 0;
+
+ __add_preferred_console(buf, idx, options, brl_options);
+ console_set_on_cmdline = 1;
+ return 1;
+}
+__setup("console=", console_setup);
+
+/**
+ * add_preferred_console - add a device to the list of preferred consoles.
+ * @name: device name
+ * @idx: device index
+ * @options: options for this console
+ *
+ * The last preferred console added will be used for kernel messages
+ * and stdin/out/err for init. Normally this is used by console_setup
+ * above to handle user-supplied console arguments; however it can also
+ * be used by arch-specific code either to override the user or more
+ * commonly to provide a default console (ie from PROM variables) when
+ * the user has not supplied one.
+ */
+int add_preferred_console(char *name, int idx, char *options)
+{
+ return __add_preferred_console(name, idx, options, NULL);
+}
+
+int update_console_cmdline(char *name, int idx, char *name_new, int idx_new, char *options)
+{
+ struct console_cmdline *c;
+ int i;
+
+ for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0]; i++)
+ if (strcmp(console_cmdline[i].name, name) == 0 &&
+ console_cmdline[i].index == idx) {
+ c = &console_cmdline[i];
+ strlcpy(c->name, name_new, sizeof(c->name));
+ c->name[sizeof(c->name) - 1] = 0;
+ c->options = options;
+ c->index = idx_new;
+ return i;
+ }
+ /* not found */
+ return -1;
+}
+
+bool console_suspend_enabled = 1;
+EXPORT_SYMBOL(console_suspend_enabled);
+
+static int __init console_suspend_disable(char *str)
+{
+ console_suspend_enabled = 0;
+ return 1;
+}
+__setup("no_console_suspend", console_suspend_disable);
+module_param_named(console_suspend, console_suspend_enabled,
+ bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(console_suspend, "suspend console during suspend"
+ " and hibernate operations");
+
+/**
+ * suspend_console - suspend the console subsystem
+ *
+ * This disables printk() while we go into suspend states
+ */
+void suspend_console(void)
+{
+ if (!console_suspend_enabled)
+ return;
+ printk("Suspending console(s) (use no_console_suspend to debug)\n");
+ console_lock();
+ console_suspended = 1;
+ up(&console_sem);
+}
+
+void resume_console(void)
+{
+ if (!console_suspend_enabled)
+ return;
+ down(&console_sem);
+ console_suspended = 0;
+ console_unlock();
+}
+
+/**
+ * console_cpu_notify - print deferred console messages after CPU hotplug
+ * @self: notifier struct
+ * @action: CPU hotplug event
+ * @hcpu: unused
+ *
+ * If printk() is called from a CPU that is not online yet, the messages
+ * will be spooled but will not show up on the console. This function is
+ * called when a new CPU comes online (or fails to come up), and ensures
+ * that any such output gets printed.
+ */
+static int __cpuinit console_cpu_notify(struct notifier_block *self,
+ unsigned long action, void *hcpu)
+{
+ switch (action) {
+ case CPU_ONLINE:
+ case CPU_DEAD:
+ case CPU_DOWN_FAILED:
+ case CPU_UP_CANCELED:
+ console_lock();
+ console_unlock();
+ }
+ return NOTIFY_OK;
+}
+
+/**
+ * console_lock - lock the console system for exclusive use.
+ *
+ * Acquires a lock which guarantees that the caller has
+ * exclusive access to the console system and the console_drivers list.
+ *
+ * Can sleep, returns nothing.
+ */
+void console_lock(void)
+{
+ might_sleep();
+
+ down(&console_sem);
+ if (console_suspended)
+ return;
+ console_locked = 1;
+ console_may_schedule = 1;
+ mutex_acquire(&console_lock_dep_map, 0, 0, _RET_IP_);
+}
+EXPORT_SYMBOL(console_lock);
+
+/**
+ * console_trylock - try to lock the console system for exclusive use.
+ *
+ * Tried to acquire a lock which guarantees that the caller has
+ * exclusive access to the console system and the console_drivers list.
+ *
+ * returns 1 on success, and 0 on failure to acquire the lock.
+ */
+int console_trylock(void)
+{
+ if (down_trylock(&console_sem))
+ return 0;
+ if (console_suspended) {
+ up(&console_sem);
+ return 0;
+ }
+ console_locked = 1;
+ console_may_schedule = 0;
+ mutex_acquire(&console_lock_dep_map, 0, 1, _RET_IP_);
+ return 1;
+}
+EXPORT_SYMBOL(console_trylock);
+
+int is_console_locked(void)
+{
+ return console_locked;
+}
+
+static void console_cont_flush(char *text, size_t size)
+{
+ unsigned long flags;
+ size_t len;
+
+ raw_spin_lock_irqsave(&logbuf_lock, flags);
+
+ if (!cont.len)
+ goto out;
+
+ /*
+ * We still queue earlier records, likely because the console was
+ * busy. The earlier ones need to be printed before this one, we
+ * did not flush any fragment so far, so just let it queue up.
+ */
+ if (console_seq < log_next_seq && !cont.cons)
+ goto out;
+
+ len = cont_print_text(text, size);
+ raw_spin_unlock(&logbuf_lock);
+ stop_critical_timings();
+ call_console_drivers(cont.level, text, len);
+ start_critical_timings();
+ local_irq_restore(flags);
+ return;
+out:
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+}
+
+/**
+ * console_unlock - unlock the console system
+ *
+ * Releases the console_lock which the caller holds on the console system
+ * and the console driver list.
+ *
+ * While the console_lock was held, console output may have been buffered
+ * by printk(). If this is the case, console_unlock(); emits
+ * the output prior to releasing the lock.
+ *
+ * If there is output waiting, we wake /dev/kmsg and syslog() users.
+ *
+ * console_unlock(); may be called from any context.
+ */
+void console_unlock(void)
+{
+ static char text[LOG_LINE_MAX + PREFIX_MAX];
+ static u64 seen_seq;
+ unsigned long flags;
+ bool wake_klogd = false;
+ bool retry;
+
+ if (console_suspended) {
+ up(&console_sem);
+ return;
+ }
+
+ console_may_schedule = 0;
+
+ /* flush buffered message fragment immediately to console */
+ console_cont_flush(text, sizeof(text));
+again:
+ for (;;) {
+ struct log *msg;
+ size_t len;
+ int level;
+
+ raw_spin_lock_irqsave(&logbuf_lock, flags);
+ if (seen_seq != log_next_seq) {
+ wake_klogd = true;
+ seen_seq = log_next_seq;
+ }
+
+ if (console_seq < log_first_seq) {
+ /* messages are gone, move to first one */
+ console_seq = log_first_seq;
+ console_idx = log_first_idx;
+ console_prev = 0;
+ }
+skip:
+ if (console_seq == log_next_seq)
+ break;
+
+ msg = log_from_idx(console_idx);
+ if (msg->flags & LOG_NOCONS) {
+ /*
+ * Skip record we have buffered and already printed
+ * directly to the console when we received it.
+ */
+ console_idx = log_next(console_idx);
+ console_seq++;
+ /*
+ * We will get here again when we register a new
+ * CON_PRINTBUFFER console. Clear the flag so we
+ * will properly dump everything later.
+ */
+ msg->flags &= ~LOG_NOCONS;
+ console_prev = msg->flags;
+ goto skip;
+ }
+
+ level = msg->level;
+ len = msg_print_text(msg, console_prev, false,
+ text, sizeof(text));
+ console_idx = log_next(console_idx);
+ console_seq++;
+ console_prev = msg->flags;
+ raw_spin_unlock(&logbuf_lock);
+
+ stop_critical_timings(); /* don't trace print latency */
+ call_console_drivers(level, text, len);
+ start_critical_timings();
+ local_irq_restore(flags);
+ }
+ console_locked = 0;
+ mutex_release(&console_lock_dep_map, 1, _RET_IP_);
+
+ /* Release the exclusive_console once it is used */
+ if (unlikely(exclusive_console))
+ exclusive_console = NULL;
+
+ raw_spin_unlock(&logbuf_lock);
+
+ up(&console_sem);
+
+ /*
+ * Someone could have filled up the buffer again, so re-check if there's
+ * something to flush. In case we cannot trylock the console_sem again,
+ * there's a new owner and the console_unlock() from them will do the
+ * flush, no worries.
+ */
+ raw_spin_lock(&logbuf_lock);
+ retry = console_seq != log_next_seq;
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+
+ if (retry && console_trylock())
+ goto again;
+
+ if (wake_klogd)
+ wake_up_klogd();
+}
+EXPORT_SYMBOL(console_unlock);
+
+/**
+ * console_conditional_schedule - yield the CPU if required
+ *
+ * If the console code is currently allowed to sleep, and
+ * if this CPU should yield the CPU to another task, do
+ * so here.
+ *
+ * Must be called within console_lock();.
+ */
+void __sched console_conditional_schedule(void)
+{
+ if (console_may_schedule)
+ cond_resched();
+}
+EXPORT_SYMBOL(console_conditional_schedule);
+
+void console_unblank(void)
+{
+ struct console *c;
+
+ /*
+ * console_unblank can no longer be called in interrupt context unless
+ * oops_in_progress is set to 1..
+ */
+ if (oops_in_progress) {
+ if (down_trylock(&console_sem) != 0)
+ return;
+ } else
+ console_lock();
+
+ console_locked = 1;
+ console_may_schedule = 0;
+ for_each_console(c)
+ if ((c->flags & CON_ENABLED) && c->unblank)
+ c->unblank();
+ console_unlock();
+}
+
+/*
+ * Return the console tty driver structure and its associated index
+ */
+struct tty_driver *console_device(int *index)
+{
+ struct console *c;
+ struct tty_driver *driver = NULL;
+
+ console_lock();
+ for_each_console(c) {
+ if (!c->device)
+ continue;
+ driver = c->device(c, index);
+ if (driver)
+ break;
+ }
+ console_unlock();
+ return driver;
+}
+
+/*
+ * Prevent further output on the passed console device so that (for example)
+ * serial drivers can disable console output before suspending a port, and can
+ * re-enable output afterwards.
+ */
+void console_stop(struct console *console)
+{
+ console_lock();
+ console->flags &= ~CON_ENABLED;
+ console_unlock();
+}
+EXPORT_SYMBOL(console_stop);
+
+void console_start(struct console *console)
+{
+ console_lock();
+ console->flags |= CON_ENABLED;
+ console_unlock();
+}
+EXPORT_SYMBOL(console_start);
+
+static int __read_mostly keep_bootcon;
+
+static int __init keep_bootcon_setup(char *str)
+{
+ keep_bootcon = 1;
+ printk(KERN_INFO "debug: skip boot console de-registration.\n");
+
+ return 0;
+}
+
+early_param("keep_bootcon", keep_bootcon_setup);
+
+/*
+ * The console driver calls this routine during kernel initialization
+ * to register the console printing procedure with printk() and to
+ * print any messages that were printed by the kernel before the
+ * console driver was initialized.
+ *
+ * This can happen pretty early during the boot process (because of
+ * early_printk) - sometimes before setup_arch() completes - be careful
+ * of what kernel features are used - they may not be initialised yet.
+ *
+ * There are two types of consoles - bootconsoles (early_printk) and
+ * "real" consoles (everything which is not a bootconsole) which are
+ * handled differently.
+ * - Any number of bootconsoles can be registered at any time.
+ * - As soon as a "real" console is registered, all bootconsoles
+ * will be unregistered automatically.
+ * - Once a "real" console is registered, any attempt to register a
+ * bootconsoles will be rejected
+ */
+void register_console(struct console *newcon)
+{
+ int i;
+ unsigned long flags;
+ struct console *bcon = NULL;
+
+ /*
+ * before we register a new CON_BOOT console, make sure we don't
+ * already have a valid console
+ */
+ if (console_drivers && newcon->flags & CON_BOOT) {
+ /* find the last or real console */
+ for_each_console(bcon) {
+ if (!(bcon->flags & CON_BOOT)) {
+ printk(KERN_INFO "Too late to register bootconsole %s%d\n",
+ newcon->name, newcon->index);
+ return;
+ }
+ }
+ }
+
+ if (console_drivers && console_drivers->flags & CON_BOOT)
+ bcon = console_drivers;
+
+ if (preferred_console < 0 || bcon || !console_drivers)
+ preferred_console = selected_console;
+
+ if (newcon->early_setup)
+ newcon->early_setup();
+
+ /*
+ * See if we want to use this console driver. If we
+ * didn't select a console we take the first one
+ * that registers here.
+ */
+ if (preferred_console < 0) {
+ if (newcon->index < 0)
+ newcon->index = 0;
+ if (newcon->setup == NULL ||
+ newcon->setup(newcon, NULL) == 0) {
+ newcon->flags |= CON_ENABLED;
+ if (newcon->device) {
+ newcon->flags |= CON_CONSDEV;
+ preferred_console = 0;
+ }
+ }
+ }
+
+ /*
+ * See if this console matches one we selected on
+ * the command line.
+ */
+ for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0];
+ i++) {
+ if (strcmp(console_cmdline[i].name, newcon->name) != 0)
+ continue;
+ if (newcon->index >= 0 &&
+ newcon->index != console_cmdline[i].index)
+ continue;
+ if (newcon->index < 0)
+ newcon->index = console_cmdline[i].index;
+#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
+ if (console_cmdline[i].brl_options) {
+ newcon->flags |= CON_BRL;
+ braille_register_console(newcon,
+ console_cmdline[i].index,
+ console_cmdline[i].options,
+ console_cmdline[i].brl_options);
+ return;
+ }
+#endif
+ if (newcon->setup &&
+ newcon->setup(newcon, console_cmdline[i].options) != 0)
+ break;
+ newcon->flags |= CON_ENABLED;
+ newcon->index = console_cmdline[i].index;
+ if (i == selected_console) {
+ newcon->flags |= CON_CONSDEV;
+ preferred_console = selected_console;
+ }
+ break;
+ }
+
+ if (!(newcon->flags & CON_ENABLED))
+ return;
+
+ /*
+ * If we have a bootconsole, and are switching to a real console,
+ * don't print everything out again, since when the boot console, and
+ * the real console are the same physical device, it's annoying to
+ * see the beginning boot messages twice
+ */
+ if (bcon && ((newcon->flags & (CON_CONSDEV | CON_BOOT)) == CON_CONSDEV))
+ newcon->flags &= ~CON_PRINTBUFFER;
+
+ /*
+ * Put this console in the list - keep the
+ * preferred driver at the head of the list.
+ */
+ console_lock();
+ if ((newcon->flags & CON_CONSDEV) || console_drivers == NULL) {
+ newcon->next = console_drivers;
+ console_drivers = newcon;
+ if (newcon->next)
+ newcon->next->flags &= ~CON_CONSDEV;
+ } else {
+ newcon->next = console_drivers->next;
+ console_drivers->next = newcon;
+ }
+ if (newcon->flags & CON_PRINTBUFFER) {
+ /*
+ * console_unlock(); will print out the buffered messages
+ * for us.
+ */
+ raw_spin_lock_irqsave(&logbuf_lock, flags);
+ console_seq = syslog_seq;
+ console_idx = syslog_idx;
+ console_prev = syslog_prev;
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+ /*
+ * We're about to replay the log buffer. Only do this to the
+ * just-registered console to avoid excessive message spam to
+ * the already-registered consoles.
+ */
+ exclusive_console = newcon;
+ }
+ console_unlock();
+ console_sysfs_notify();
+
+ /*
+ * By unregistering the bootconsoles after we enable the real console
+ * we get the "console xxx enabled" message on all the consoles -
+ * boot consoles, real consoles, etc - this is to ensure that end
+ * users know there might be something in the kernel's log buffer that
+ * went to the bootconsole (that they do not see on the real console)
+ */
+ if (bcon &&
+ ((newcon->flags & (CON_CONSDEV | CON_BOOT)) == CON_CONSDEV) &&
+ !keep_bootcon) {
+ /* we need to iterate through twice, to make sure we print
+ * everything out, before we unregister the console(s)
+ */
+ printk(KERN_INFO "console [%s%d] enabled, bootconsole disabled\n",
+ newcon->name, newcon->index);
+ for_each_console(bcon)
+ if (bcon->flags & CON_BOOT)
+ unregister_console(bcon);
+ } else {
+ printk(KERN_INFO "%sconsole [%s%d] enabled\n",
+ (newcon->flags & CON_BOOT) ? "boot" : "" ,
+ newcon->name, newcon->index);
+ }
+}
+EXPORT_SYMBOL(register_console);
+
+int unregister_console(struct console *console)
+{
+ struct console *a, *b;
+ int res = 1;
+
+#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
+ if (console->flags & CON_BRL)
+ return braille_unregister_console(console);
+#endif
+
+ console_lock();
+ if (console_drivers == console) {
+ console_drivers=console->next;
+ res = 0;
+ } else if (console_drivers) {
+ for (a=console_drivers->next, b=console_drivers ;
+ a; b=a, a=b->next) {
+ if (a == console) {
+ b->next = a->next;
+ res = 0;
+ break;
+ }
+ }
+ }
+
+ /*
+ * If this isn't the last console and it has CON_CONSDEV set, we
+ * need to set it on the next preferred console.
+ */
+ if (console_drivers != NULL && console->flags & CON_CONSDEV)
+ console_drivers->flags |= CON_CONSDEV;
+
+ console_unlock();
+ console_sysfs_notify();
+ return res;
+}
+EXPORT_SYMBOL(unregister_console);
+
+static int __init printk_late_init(void)
+{
+ struct console *con;
+
+ for_each_console(con) {
+ if (!keep_bootcon && con->flags & CON_BOOT) {
+ printk(KERN_INFO "turn off boot console %s%d\n",
+ con->name, con->index);
+ unregister_console(con);
+ }
+ }
+ hotcpu_notifier(console_cpu_notify, 0);
+ return 0;
+}
+late_initcall(printk_late_init);
+
+#if defined CONFIG_PRINTK
+/*
+ * Delayed printk version, for scheduler-internal messages:
+ */
+#define PRINTK_BUF_SIZE 512
+
+#define PRINTK_PENDING_WAKEUP 0x01
+#define PRINTK_PENDING_SCHED 0x02
+
+static DEFINE_PER_CPU(int, printk_pending);
+static DEFINE_PER_CPU(char [PRINTK_BUF_SIZE], printk_sched_buf);
+
+static void wake_up_klogd_work_func(struct irq_work *irq_work)
+{
+ int pending = __this_cpu_xchg(printk_pending, 0);
+
+ if (pending & PRINTK_PENDING_SCHED) {
+ char *buf = __get_cpu_var(printk_sched_buf);
+ printk(KERN_WARNING "[sched_delayed] %s", buf);
+ }
+
+ if (pending & PRINTK_PENDING_WAKEUP)
+ wake_up_interruptible(&log_wait);
+}
+
+static DEFINE_PER_CPU(struct irq_work, wake_up_klogd_work) = {
+ .func = wake_up_klogd_work_func,
+ .flags = IRQ_WORK_LAZY,
+};
+
+void wake_up_klogd(void)
+{
+ preempt_disable();
+ if (waitqueue_active(&log_wait)) {
+ this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP);
+ irq_work_queue(&__get_cpu_var(wake_up_klogd_work));
+ }
+ preempt_enable();
+}
+
+int printk_sched(const char *fmt, ...)
+{
+ unsigned long flags;
+ va_list args;
+ char *buf;
+ int r;
+
+ local_irq_save(flags);
+ buf = __get_cpu_var(printk_sched_buf);
+
+ va_start(args, fmt);
+ r = vsnprintf(buf, PRINTK_BUF_SIZE, fmt, args);
+ va_end(args);
+
+ __this_cpu_or(printk_pending, PRINTK_PENDING_SCHED);
+ irq_work_queue(&__get_cpu_var(wake_up_klogd_work));
+ local_irq_restore(flags);
+
+ return r;
+}
+
+/*
+ * printk rate limiting, lifted from the networking subsystem.
+ *
+ * This enforces a rate limit: not more than 10 kernel messages
+ * every 5s to make a denial-of-service attack impossible.
+ */
+DEFINE_RATELIMIT_STATE(printk_ratelimit_state, 5 * HZ, 10);
+
+int __printk_ratelimit(const char *func)
+{
+ return ___ratelimit(&printk_ratelimit_state, func);
+}
+EXPORT_SYMBOL(__printk_ratelimit);
+
+/**
+ * printk_timed_ratelimit - caller-controlled printk ratelimiting
+ * @caller_jiffies: pointer to caller's state
+ * @interval_msecs: minimum interval between prints
+ *
+ * printk_timed_ratelimit() returns true if more than @interval_msecs
+ * milliseconds have elapsed since the last time printk_timed_ratelimit()
+ * returned true.
+ */
+bool printk_timed_ratelimit(unsigned long *caller_jiffies,
+ unsigned int interval_msecs)
+{
+ if (*caller_jiffies == 0
+ || !time_in_range(jiffies, *caller_jiffies,
+ *caller_jiffies
+ + msecs_to_jiffies(interval_msecs))) {
+ *caller_jiffies = jiffies;
+ return true;
+ }
+ return false;
+}
+EXPORT_SYMBOL(printk_timed_ratelimit);
+
+static DEFINE_SPINLOCK(dump_list_lock);
+static LIST_HEAD(dump_list);
+
+/**
+ * kmsg_dump_register - register a kernel log dumper.
+ * @dumper: pointer to the kmsg_dumper structure
+ *
+ * Adds a kernel log dumper to the system. The dump callback in the
+ * structure will be called when the kernel oopses or panics and must be
+ * set. Returns zero on success and %-EINVAL or %-EBUSY otherwise.
+ */
+int kmsg_dump_register(struct kmsg_dumper *dumper)
+{
+ unsigned long flags;
+ int err = -EBUSY;
+
+ /* The dump callback needs to be set */
+ if (!dumper->dump)
+ return -EINVAL;
+
+ spin_lock_irqsave(&dump_list_lock, flags);
+ /* Don't allow registering multiple times */
+ if (!dumper->registered) {
+ dumper->registered = 1;
+ list_add_tail_rcu(&dumper->list, &dump_list);
+ err = 0;
+ }
+ spin_unlock_irqrestore(&dump_list_lock, flags);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(kmsg_dump_register);
+
+/**
+ * kmsg_dump_unregister - unregister a kmsg dumper.
+ * @dumper: pointer to the kmsg_dumper structure
+ *
+ * Removes a dump device from the system. Returns zero on success and
+ * %-EINVAL otherwise.
+ */
+int kmsg_dump_unregister(struct kmsg_dumper *dumper)
+{
+ unsigned long flags;
+ int err = -EINVAL;
+
+ spin_lock_irqsave(&dump_list_lock, flags);
+ if (dumper->registered) {
+ dumper->registered = 0;
+ list_del_rcu(&dumper->list);
+ err = 0;
+ }
+ spin_unlock_irqrestore(&dump_list_lock, flags);
+ synchronize_rcu();
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(kmsg_dump_unregister);
+
+static bool always_kmsg_dump;
+module_param_named(always_kmsg_dump, always_kmsg_dump, bool, S_IRUGO | S_IWUSR);
+
+/**
+ * kmsg_dump - dump kernel log to kernel message dumpers.
+ * @reason: the reason (oops, panic etc) for dumping
+ *
+ * Call each of the registered dumper's dump() callback, which can
+ * retrieve the kmsg records with kmsg_dump_get_line() or
+ * kmsg_dump_get_buffer().
+ */
+void kmsg_dump(enum kmsg_dump_reason reason)
+{
+ struct kmsg_dumper *dumper;
+ unsigned long flags;
+
+ if ((reason > KMSG_DUMP_OOPS) && !always_kmsg_dump)
+ return;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(dumper, &dump_list, list) {
+ if (dumper->max_reason && reason > dumper->max_reason)
+ continue;
+
+ /* initialize iterator with data about the stored records */
+ dumper->active = true;
+
+ raw_spin_lock_irqsave(&logbuf_lock, flags);
+ dumper->cur_seq = clear_seq;
+ dumper->cur_idx = clear_idx;
+ dumper->next_seq = log_next_seq;
+ dumper->next_idx = log_next_idx;
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+
+ /* invoke dumper which will iterate over records */
+ dumper->dump(dumper, reason);
+
+ /* reset iterator */
+ dumper->active = false;
+ }
+ rcu_read_unlock();
+}
+
+/**
+ * kmsg_dump_get_line_nolock - retrieve one kmsg log line (unlocked version)
+ * @dumper: registered kmsg dumper
+ * @syslog: include the "<4>" prefixes
+ * @line: buffer to copy the line to
+ * @size: maximum size of the buffer
+ * @len: length of line placed into buffer
+ *
+ * Start at the beginning of the kmsg buffer, with the oldest kmsg
+ * record, and copy one record into the provided buffer.
+ *
+ * Consecutive calls will return the next available record moving
+ * towards the end of the buffer with the youngest messages.
+ *
+ * A return value of FALSE indicates that there are no more records to
+ * read.
+ *
+ * The function is similar to kmsg_dump_get_line(), but grabs no locks.
+ */
+bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog,
+ char *line, size_t size, size_t *len)
+{
+ struct log *msg;
+ size_t l = 0;
+ bool ret = false;
+
+ if (!dumper->active)
+ goto out;
+
+ if (dumper->cur_seq < log_first_seq) {
+ /* messages are gone, move to first available one */
+ dumper->cur_seq = log_first_seq;
+ dumper->cur_idx = log_first_idx;
+ }
+
+ /* last entry */
+ if (dumper->cur_seq >= log_next_seq)
+ goto out;
+
+ msg = log_from_idx(dumper->cur_idx);
+ l = msg_print_text(msg, 0, syslog, line, size);
+
+ dumper->cur_idx = log_next(dumper->cur_idx);
+ dumper->cur_seq++;
+ ret = true;
+out:
+ if (len)
+ *len = l;
+ return ret;
+}
+
+/**
+ * kmsg_dump_get_line - retrieve one kmsg log line
+ * @dumper: registered kmsg dumper
+ * @syslog: include the "<4>" prefixes
+ * @line: buffer to copy the line to
+ * @size: maximum size of the buffer
+ * @len: length of line placed into buffer
+ *
+ * Start at the beginning of the kmsg buffer, with the oldest kmsg
+ * record, and copy one record into the provided buffer.
+ *
+ * Consecutive calls will return the next available record moving
+ * towards the end of the buffer with the youngest messages.
+ *
+ * A return value of FALSE indicates that there are no more records to
+ * read.
+ */
+bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog,
+ char *line, size_t size, size_t *len)
+{
+ unsigned long flags;
+ bool ret;
+
+ raw_spin_lock_irqsave(&logbuf_lock, flags);
+ ret = kmsg_dump_get_line_nolock(dumper, syslog, line, size, len);
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(kmsg_dump_get_line);
+
+/**
+ * kmsg_dump_get_buffer - copy kmsg log lines
+ * @dumper: registered kmsg dumper
+ * @syslog: include the "<4>" prefixes
+ * @buf: buffer to copy the line to
+ * @size: maximum size of the buffer
+ * @len: length of line placed into buffer
+ *
+ * Start at the end of the kmsg buffer and fill the provided buffer
+ * with as many of the the *youngest* kmsg records that fit into it.
+ * If the buffer is large enough, all available kmsg records will be
+ * copied with a single call.
+ *
+ * Consecutive calls will fill the buffer with the next block of
+ * available older records, not including the earlier retrieved ones.
+ *
+ * A return value of FALSE indicates that there are no more records to
+ * read.
+ */
+bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
+ char *buf, size_t size, size_t *len)
+{
+ unsigned long flags;
+ u64 seq;
+ u32 idx;
+ u64 next_seq;
+ u32 next_idx;
+ enum log_flags prev;
+ size_t l = 0;
+ bool ret = false;
+
+ if (!dumper->active)
+ goto out;
+
+ raw_spin_lock_irqsave(&logbuf_lock, flags);
+ if (dumper->cur_seq < log_first_seq) {
+ /* messages are gone, move to first available one */
+ dumper->cur_seq = log_first_seq;
+ dumper->cur_idx = log_first_idx;
+ }
+
+ /* last entry */
+ if (dumper->cur_seq >= dumper->next_seq) {
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+ goto out;
+ }
+
+ /* calculate length of entire buffer */
+ seq = dumper->cur_seq;
+ idx = dumper->cur_idx;
+ prev = 0;
+ while (seq < dumper->next_seq) {
+ struct log *msg = log_from_idx(idx);
+
+ l += msg_print_text(msg, prev, true, NULL, 0);
+ idx = log_next(idx);
+ seq++;
+ prev = msg->flags;
+ }
+
+ /* move first record forward until length fits into the buffer */
+ seq = dumper->cur_seq;
+ idx = dumper->cur_idx;
+ prev = 0;
+ while (l > size && seq < dumper->next_seq) {
+ struct log *msg = log_from_idx(idx);
+
+ l -= msg_print_text(msg, prev, true, NULL, 0);
+ idx = log_next(idx);
+ seq++;
+ prev = msg->flags;
+ }
+
+ /* last message in next interation */
+ next_seq = seq;
+ next_idx = idx;
+
+ l = 0;
+ prev = 0;
+ while (seq < dumper->next_seq) {
+ struct log *msg = log_from_idx(idx);
+
+ l += msg_print_text(msg, prev, syslog, buf + l, size - l);
+ idx = log_next(idx);
+ seq++;
+ prev = msg->flags;
+ }
+
+ dumper->next_seq = next_seq;
+ dumper->next_idx = next_idx;
+ ret = true;
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+out:
+ if (len)
+ *len = l;
+ return ret;
+}
+EXPORT_SYMBOL_GPL(kmsg_dump_get_buffer);
+
+/**
+ * kmsg_dump_rewind_nolock - reset the interator (unlocked version)
+ * @dumper: registered kmsg dumper
+ *
+ * Reset the dumper's iterator so that kmsg_dump_get_line() and
+ * kmsg_dump_get_buffer() can be called again and used multiple
+ * times within the same dumper.dump() callback.
+ *
+ * The function is similar to kmsg_dump_rewind(), but grabs no locks.
+ */
+void kmsg_dump_rewind_nolock(struct kmsg_dumper *dumper)
+{
+ dumper->cur_seq = clear_seq;
+ dumper->cur_idx = clear_idx;
+ dumper->next_seq = log_next_seq;
+ dumper->next_idx = log_next_idx;
+}
+
+/**
+ * kmsg_dump_rewind - reset the interator
+ * @dumper: registered kmsg dumper
+ *
+ * Reset the dumper's iterator so that kmsg_dump_get_line() and
+ * kmsg_dump_get_buffer() can be called again and used multiple
+ * times within the same dumper.dump() callback.
+ */
+void kmsg_dump_rewind(struct kmsg_dumper *dumper)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&logbuf_lock, flags);
+ kmsg_dump_rewind_nolock(dumper);
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+}
+EXPORT_SYMBOL_GPL(kmsg_dump_rewind);
+
+static char dump_stack_arch_desc_str[128];
+
+/**
+ * dump_stack_set_arch_desc - set arch-specific str to show with task dumps
+ * @fmt: printf-style format string
+ * @...: arguments for the format string
+ *
+ * The configured string will be printed right after utsname during task
+ * dumps. Usually used to add arch-specific system identifiers. If an
+ * arch wants to make use of such an ID string, it should initialize this
+ * as soon as possible during boot.
+ */
+void __init dump_stack_set_arch_desc(const char *fmt, ...)
+{
+ va_list args;
+
+ va_start(args, fmt);
+ vsnprintf(dump_stack_arch_desc_str, sizeof(dump_stack_arch_desc_str),
+ fmt, args);
+ va_end(args);
+}
+
+/**
+ * dump_stack_print_info - print generic debug info for dump_stack()
+ * @log_lvl: log level
+ *
+ * Arch-specific dump_stack() implementations can use this function to
+ * print out the same debug information as the generic dump_stack().
+ */
+void dump_stack_print_info(const char *log_lvl)
+{
+ printk("%sCPU: %d PID: %d Comm: %.20s %s %s %.*s\n",
+ log_lvl, raw_smp_processor_id(), current->pid, current->comm,
+ print_tainted(), init_utsname()->release,
+ (int)strcspn(init_utsname()->version, " "),
+ init_utsname()->version);
+
+ if (dump_stack_arch_desc_str[0] != '\0')
+ printk("%sHardware name: %s\n",
+ log_lvl, dump_stack_arch_desc_str);
+
+ print_worker_info(log_lvl, current);
+}
+
+/**
+ * show_regs_print_info - print generic debug info for show_regs()
+ * @log_lvl: log level
+ *
+ * show_regs() implementations can use this function to print out generic
+ * debug information.
+ */
+void show_regs_print_info(const char *log_lvl)
+{
+ dump_stack_print_info(log_lvl);
+
+ printk("%stask: %p ti: %p task.ti: %p\n",
+ log_lvl, current, current_thread_info(),
+ task_thread_info(current));
+}
+
+#endif
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 5ac63c9a995a..f462df1da410 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6571,13 +6571,24 @@ static inline int preempt_count_equals(int preempt_offset)
return (nested == preempt_offset);
}
+static int __might_sleep_init_called;
+int __init __might_sleep_init(void)
+{
+ __might_sleep_init_called = 1;
+ return 0;
+}
+early_initcall(__might_sleep_init);
+
void __might_sleep(const char *file, int line, int preempt_offset)
{
static unsigned long prev_jiffy; /* ratelimiting */
rcu_sleep_check(); /* WARN_ON_ONCE() by default, no rate limit reqd. */
if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) ||
- system_state != SYSTEM_RUNNING || oops_in_progress)
+ oops_in_progress)
+ return;
+ if (system_state != SYSTEM_RUNNING &&
+ (!__might_sleep_init_called || system_state != SYSTEM_BOOTING))
return;
if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
return;
diff --git a/kernel/sys.c b/kernel/sys.c
index c18ecca575b4..eced15d4e26d 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -42,6 +42,8 @@
#include <linux/syscore_ops.h>
#include <linux/version.h>
#include <linux/ctype.h>
+#include <linux/mm.h>
+#include <linux/mempolicy.h>
#include <linux/compat.h>
#include <linux/syscalls.h>
@@ -1836,6 +1838,146 @@ static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
}
#endif
+
+static int prctl_update_vma_anon_name(struct vm_area_struct *vma,
+ struct vm_area_struct **prev,
+ unsigned long start, unsigned long end,
+ const char __user *name_addr)
+{
+ struct mm_struct * mm = vma->vm_mm;
+ int error = 0;
+ pgoff_t pgoff;
+
+ if (name_addr == vma_get_anon_name(vma)) {
+ *prev = vma;
+ goto out;
+ }
+
+ pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
+ *prev = vma_merge(mm, *prev, start, end, vma->vm_flags, vma->anon_vma,
+ vma->vm_file, pgoff, vma_policy(vma),
+ name_addr);
+ if (*prev) {
+ vma = *prev;
+ goto success;
+ }
+
+ *prev = vma;
+
+ if (start != vma->vm_start) {
+ error = split_vma(mm, vma, start, 1);
+ if (error)
+ goto out;
+ }
+
+ if (end != vma->vm_end) {
+ error = split_vma(mm, vma, end, 0);
+ if (error)
+ goto out;
+ }
+
+success:
+ if (!vma->vm_file)
+ vma->shared.anon_name = name_addr;
+
+out:
+ if (error == -ENOMEM)
+ error = -EAGAIN;
+ return error;
+}
+
+static int prctl_set_vma_anon_name(unsigned long start, unsigned long end,
+ unsigned long arg)
+{
+ unsigned long tmp;
+ struct vm_area_struct * vma, *prev;
+ int unmapped_error = 0;
+ int error = -EINVAL;
+
+ /*
+ * If the interval [start,end) covers some unmapped address
+ * ranges, just ignore them, but return -ENOMEM at the end.
+ * - this matches the handling in madvise.
+ */
+ vma = find_vma_prev(current->mm, start, &prev);
+ if (vma && start > vma->vm_start)
+ prev = vma;
+
+ for (;;) {
+ /* Still start < end. */
+ error = -ENOMEM;
+ if (!vma)
+ return error;
+
+ /* Here start < (end|vma->vm_end). */
+ if (start < vma->vm_start) {
+ unmapped_error = -ENOMEM;
+ start = vma->vm_start;
+ if (start >= end)
+ return error;
+ }
+
+ /* Here vma->vm_start <= start < (end|vma->vm_end) */
+ tmp = vma->vm_end;
+ if (end < tmp)
+ tmp = end;
+
+ /* Here vma->vm_start <= start < tmp <= (end|vma->vm_end). */
+ error = prctl_update_vma_anon_name(vma, &prev, start, end,
+ (const char __user *)arg);
+ if (error)
+ return error;
+ start = tmp;
+ if (prev && start < prev->vm_end)
+ start = prev->vm_end;
+ error = unmapped_error;
+ if (start >= end)
+ return error;
+ if (prev)
+ vma = prev->vm_next;
+ else /* madvise_remove dropped mmap_sem */
+ vma = find_vma(current->mm, start);
+ }
+}
+
+static int prctl_set_vma(unsigned long opt, unsigned long start,
+ unsigned long len_in, unsigned long arg)
+{
+ struct mm_struct *mm = current->mm;
+ int error;
+ unsigned long len;
+ unsigned long end;
+
+ if (start & ~PAGE_MASK)
+ return -EINVAL;
+ len = (len_in + ~PAGE_MASK) & PAGE_MASK;
+
+ /* Check to see whether len was rounded up from small -ve to zero */
+ if (len_in && !len)
+ return -EINVAL;
+
+ end = start + len;
+ if (end < start)
+ return -EINVAL;
+
+ if (end == start)
+ return 0;
+
+ down_write(&mm->mmap_sem);
+
+ switch (opt) {
+ case PR_SET_VMA_ANON_NAME:
+ error = prctl_set_vma_anon_name(start, end, arg);
+ break;
+ default:
+ error = -EINVAL;
+ }
+
+ up_write(&mm->mmap_sem);
+
+ return error;
+}
+
SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
unsigned long, arg4, unsigned long, arg5)
{
@@ -1963,6 +2105,9 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
else
return -EINVAL;
break;
+ case PR_SET_VMA:
+ error = prctl_set_vma(arg2, arg3, arg4, arg5);
+ break;
default:
return -EINVAL;
}
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index b2f06f3c6a3f..b43d4e3e1176 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -105,6 +105,8 @@ extern char core_pattern[];
extern unsigned int core_pipe_limit;
#endif
extern int pid_max;
+extern int extra_free_kbytes;
+extern int min_free_order_shift;
extern int pid_max_min, pid_max_max;
extern int percpu_pagelist_fraction;
extern int compat_log;
@@ -1281,6 +1283,21 @@ static struct ctl_table vm_table[] = {
.extra1 = &zero,
},
{
+ .procname = "extra_free_kbytes",
+ .data = &extra_free_kbytes,
+ .maxlen = sizeof(extra_free_kbytes),
+ .mode = 0644,
+ .proc_handler = min_free_kbytes_sysctl_handler,
+ .extra1 = &zero,
+ },
+ {
+ .procname = "min_free_order_shift",
+ .data = &min_free_order_shift,
+ .maxlen = sizeof(min_free_order_shift),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec
+ },
+ {
.procname = "percpu_pagelist_fraction",
.data = &percpu_pagelist_fraction,
.maxlen = sizeof(percpu_pagelist_fraction),
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index eec50fcef9e4..d17b4d0ed8f4 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -345,7 +345,6 @@ int alarm_start_relative(struct alarm *alarm, ktime_t start)
start = ktime_add(start, base->gettime());
return alarm_start(alarm, start);
}
-EXPORT_SYMBOL_GPL(alarm_start_relative);
void alarm_restart(struct alarm *alarm)
{
@@ -358,7 +357,6 @@ void alarm_restart(struct alarm *alarm)
alarmtimer_enqueue(base, alarm);
spin_unlock_irqrestore(&base->lock, flags);
}
-EXPORT_SYMBOL_GPL(alarm_restart);
/**
* alarm_try_to_cancel - Tries to cancel an alarm timer
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 015f85aaca08..e24c188cbbcc 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -82,6 +82,9 @@ config EVENT_TRACING
select CONTEXT_SWITCH_TRACER
bool
+config GPU_TRACEPOINTS
+ bool
+
config CONTEXT_SWITCH_TRACER
bool
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index d7e2068e4b71..45012122fbb6 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -60,5 +60,6 @@ obj-$(CONFIG_KGDB_KDB) += trace_kdb.o
endif
obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o
obj-$(CONFIG_UPROBE_EVENT) += trace_uprobe.o
+obj-$(CONFIG_GPU_TRACEPOINTS) += gpu-traces.o
libftrace-y := ftrace.o
diff --git a/kernel/trace/gpu-traces.c b/kernel/trace/gpu-traces.c
new file mode 100644
index 000000000000..a4b3f00faee3
--- /dev/null
+++ b/kernel/trace/gpu-traces.c
@@ -0,0 +1,23 @@
+/*
+ * GPU tracepoints
+ *
+ * Copyright (C) 2013 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/module.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/gpu.h>
+
+EXPORT_TRACEPOINT_SYMBOL(gpu_sched_switch);
+EXPORT_TRACEPOINT_SYMBOL(gpu_job_enqueue);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 7974ba20557d..64042c0be0f3 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -733,6 +733,7 @@ static const char *trace_options[] = {
"irq-info",
"markers",
"function-trace",
+ "print-tgid",
NULL
};
@@ -1242,6 +1243,7 @@ void tracing_reset_all_online_cpus(void)
static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
static unsigned map_cmdline_to_pid[SAVED_CMDLINES];
static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN];
+static unsigned saved_tgids[SAVED_CMDLINES];
static int cmdline_idx;
static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED;
@@ -1445,6 +1447,7 @@ static void trace_save_cmdline(struct task_struct *tsk)
}
memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN);
+ saved_tgids[idx] = tsk->tgid;
arch_spin_unlock(&trace_cmdline_lock);
}
@@ -1480,6 +1483,25 @@ void trace_find_cmdline(int pid, char comm[])
preempt_enable();
}
+int trace_find_tgid(int pid)
+{
+ unsigned map;
+ int tgid;
+
+ preempt_disable();
+ arch_spin_lock(&trace_cmdline_lock);
+ map = map_pid_to_cmdline[pid];
+ if (map != NO_CMDLINE_MAP)
+ tgid = saved_tgids[map];
+ else
+ tgid = -1;
+
+ arch_spin_unlock(&trace_cmdline_lock);
+ preempt_enable();
+
+ return tgid;
+}
+
void tracing_record_cmdline(struct task_struct *tsk)
{
if (atomic_read(&trace_record_cmdline_disabled) || !tracing_is_on())
@@ -2427,6 +2449,13 @@ static void print_func_help_header(struct trace_buffer *buf, struct seq_file *m)
seq_puts(m, "# | | | | |\n");
}
+static void print_func_help_header_tgid(struct trace_buffer *buf, struct seq_file *m)
+{
+ print_event_info(buf, m);
+ seq_puts(m, "# TASK-PID TGID CPU# TIMESTAMP FUNCTION\n");
+ seq_puts(m, "# | | | | | |\n");
+}
+
static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file *m)
{
print_event_info(buf, m);
@@ -2439,6 +2468,18 @@ static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file
seq_puts(m, "# | | | |||| | |\n");
}
+static void print_func_help_header_irq_tgid(struct trace_buffer *buf, struct seq_file *m)
+{
+ print_event_info(buf, m);
+ seq_puts(m, "# _-----=> irqs-off\n");
+ seq_puts(m, "# / _----=> need-resched\n");
+ seq_puts(m, "# | / _---=> hardirq/softirq\n");
+ seq_puts(m, "# || / _--=> preempt-depth\n");
+ seq_puts(m, "# ||| / delay\n");
+ seq_puts(m, "# TASK-PID TGID CPU# |||| TIMESTAMP FUNCTION\n");
+ seq_puts(m, "# | | | | |||| | |\n");
+}
+
void
print_trace_header(struct seq_file *m, struct trace_iterator *iter)
{
@@ -2739,9 +2780,15 @@ void trace_default_header(struct seq_file *m)
} else {
if (!(trace_flags & TRACE_ITER_VERBOSE)) {
if (trace_flags & TRACE_ITER_IRQ_INFO)
- print_func_help_header_irq(iter->trace_buffer, m);
+ if (trace_flags & TRACE_ITER_TGID)
+ print_func_help_header_irq_tgid(iter->trace_buffer, m);
+ else
+ print_func_help_header_irq(iter->trace_buffer, m);
else
- print_func_help_header(iter->trace_buffer, m);
+ if (trace_flags & TRACE_ITER_TGID)
+ print_func_help_header_tgid(iter->trace_buffer, m);
+ else
+ print_func_help_header(iter->trace_buffer, m);
}
}
}
@@ -3590,9 +3637,53 @@ tracing_saved_cmdlines_read(struct file *file, char __user *ubuf,
}
static const struct file_operations tracing_saved_cmdlines_fops = {
- .open = tracing_open_generic,
- .read = tracing_saved_cmdlines_read,
- .llseek = generic_file_llseek,
+ .open = tracing_open_generic,
+ .read = tracing_saved_cmdlines_read,
+ .llseek = generic_file_llseek,
+};
+
+static ssize_t
+tracing_saved_tgids_read(struct file *file, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char *file_buf;
+ char *buf;
+ int len = 0;
+ int pid;
+ int i;
+
+ file_buf = kmalloc(SAVED_CMDLINES*(16+1+16), GFP_KERNEL);
+ if (!file_buf)
+ return -ENOMEM;
+
+ buf = file_buf;
+
+ for (i = 0; i < SAVED_CMDLINES; i++) {
+ int tgid;
+ int r;
+
+ pid = map_cmdline_to_pid[i];
+ if (pid == -1 || pid == NO_CMDLINE_MAP)
+ continue;
+
+ tgid = trace_find_tgid(pid);
+ r = sprintf(buf, "%d %d\n", pid, tgid);
+ buf += r;
+ len += r;
+ }
+
+ len = simple_read_from_buffer(ubuf, cnt, ppos,
+ file_buf, len);
+
+ kfree(file_buf);
+
+ return len;
+}
+
+static const struct file_operations tracing_saved_tgids_fops = {
+ .open = tracing_open_generic,
+ .read = tracing_saved_tgids_read,
+ .llseek = generic_file_llseek,
};
static ssize_t
@@ -6125,6 +6216,9 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
trace_create_file("trace_marker", 0220, d_tracer,
tr, &tracing_mark_fops);
+ trace_create_file("saved_tgids", 0444, d_tracer,
+ tr, &tracing_saved_tgids_fops);
+
trace_create_file("trace_clock", 0644, d_tracer, tr,
&trace_clock_fops);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 10c86fb7a2b4..aaf5ff3632a1 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -640,6 +640,7 @@ static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
extern cycle_t ftrace_now(int cpu);
extern void trace_find_cmdline(int pid, char comm[]);
+extern int trace_find_tgid(int pid);
#ifdef CONFIG_DYNAMIC_FTRACE
extern unsigned long ftrace_update_tot_cnt;
@@ -863,6 +864,7 @@ enum trace_iterator_flags {
TRACE_ITER_IRQ_INFO = 0x800000,
TRACE_ITER_MARKERS = 0x1000000,
TRACE_ITER_FUNCTION = 0x2000000,
+ TRACE_ITER_TGID = 0x4000000,
};
/*
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index b5c09242683d..4afc1ca69e1e 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -46,6 +46,8 @@ struct fgraph_data {
#define TRACE_GRAPH_PRINT_DURATION 0x10
#define TRACE_GRAPH_PRINT_ABS_TIME 0x20
#define TRACE_GRAPH_PRINT_IRQS 0x40
+#define TRACE_GRAPH_PRINT_FLAT 0x80
+
static unsigned int max_depth;
@@ -64,6 +66,8 @@ static struct tracer_opt trace_opts[] = {
{ TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) },
/* Display interrupts */
{ TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) },
+ /* Use standard trace formatting rather than hierarchical */
+ { TRACER_OPT(funcgraph-flat, TRACE_GRAPH_PRINT_FLAT) },
{ } /* Empty entry */
};
@@ -1234,6 +1238,9 @@ print_graph_function_flags(struct trace_iterator *iter, u32 flags)
int cpu = iter->cpu;
int ret;
+ if (flags & TRACE_GRAPH_PRINT_FLAT)
+ return TRACE_TYPE_UNHANDLED;
+
if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) {
per_cpu_ptr(data->cpu_data, cpu)->ignore = 0;
return TRACE_TYPE_HANDLED;
@@ -1364,6 +1371,11 @@ void print_graph_headers_flags(struct seq_file *s, u32 flags)
{
struct trace_iterator *iter = s->private;
+ if (flags & TRACE_GRAPH_PRINT_FLAT) {
+ trace_default_header(s);
+ return;
+ }
+
if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
return;
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 34e7cbac0c9c..df2ce5bb56ea 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -702,11 +702,25 @@ int trace_print_context(struct trace_iterator *iter)
unsigned long secs, usec_rem;
char comm[TASK_COMM_LEN];
int ret;
+ int tgid;
trace_find_cmdline(entry->pid, comm);
- ret = trace_seq_printf(s, "%16s-%-5d [%03d] ",
- comm, entry->pid, iter->cpu);
+ ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
+ if (!ret)
+ return 0;
+
+ if (trace_flags & TRACE_ITER_TGID) {
+ tgid = trace_find_tgid(entry->pid);
+ if (tgid < 0)
+ ret = trace_seq_puts(s, "(-----) ");
+ else
+ ret = trace_seq_printf(s, "(%5d) ", tgid);
+ if (!ret)
+ return 0;
+ }
+
+ ret = trace_seq_printf(s, "[%03d] ", iter->cpu);
if (!ret)
return 0;
@@ -1035,6 +1049,168 @@ static struct trace_event trace_fn_event = {
.funcs = &trace_fn_funcs,
};
+/* TRACE_GRAPH_ENT */
+static enum print_line_t trace_graph_ent_trace(struct trace_iterator *iter, int flags,
+ struct trace_event *event)
+{
+ struct trace_seq *s = &iter->seq;
+ struct ftrace_graph_ent_entry *field;
+
+ trace_assign_type(field, iter->ent);
+
+ if (!trace_seq_puts(s, "graph_ent: func="))
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ if (!seq_print_ip_sym(s, field->graph_ent.func, flags))
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ if (!trace_seq_puts(s, "\n"))
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t trace_graph_ent_raw(struct trace_iterator *iter, int flags,
+ struct trace_event *event)
+{
+ struct ftrace_graph_ent_entry *field;
+
+ trace_assign_type(field, iter->ent);
+
+ if (!trace_seq_printf(&iter->seq, "%lx %d\n",
+ field->graph_ent.func,
+ field->graph_ent.depth))
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t trace_graph_ent_hex(struct trace_iterator *iter, int flags,
+ struct trace_event *event)
+{
+ struct ftrace_graph_ent_entry *field;
+ struct trace_seq *s = &iter->seq;
+
+ trace_assign_type(field, iter->ent);
+
+ SEQ_PUT_HEX_FIELD_RET(s, field->graph_ent.func);
+ SEQ_PUT_HEX_FIELD_RET(s, field->graph_ent.depth);
+
+ return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t trace_graph_ent_bin(struct trace_iterator *iter, int flags,
+ struct trace_event *event)
+{
+ struct ftrace_graph_ent_entry *field;
+ struct trace_seq *s = &iter->seq;
+
+ trace_assign_type(field, iter->ent);
+
+ SEQ_PUT_FIELD_RET(s, field->graph_ent.func);
+ SEQ_PUT_FIELD_RET(s, field->graph_ent.depth);
+
+ return TRACE_TYPE_HANDLED;
+}
+
+static struct trace_event_functions trace_graph_ent_funcs = {
+ .trace = trace_graph_ent_trace,
+ .raw = trace_graph_ent_raw,
+ .hex = trace_graph_ent_hex,
+ .binary = trace_graph_ent_bin,
+};
+
+static struct trace_event trace_graph_ent_event = {
+ .type = TRACE_GRAPH_ENT,
+ .funcs = &trace_graph_ent_funcs,
+};
+
+/* TRACE_GRAPH_RET */
+static enum print_line_t trace_graph_ret_trace(struct trace_iterator *iter, int flags,
+ struct trace_event *event)
+{
+ struct trace_seq *s = &iter->seq;
+ struct trace_entry *entry = iter->ent;
+ struct ftrace_graph_ret_entry *field;
+
+ trace_assign_type(field, entry);
+
+ if (!trace_seq_puts(s, "graph_ret: func="))
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ if (!seq_print_ip_sym(s, field->ret.func, flags))
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ if (!trace_seq_puts(s, "\n"))
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t trace_graph_ret_raw(struct trace_iterator *iter, int flags,
+ struct trace_event *event)
+{
+ struct ftrace_graph_ret_entry *field;
+
+ trace_assign_type(field, iter->ent);
+
+ if (!trace_seq_printf(&iter->seq, "%lx %lld %lld %ld %d\n",
+ field->ret.func,
+ field->ret.calltime,
+ field->ret.rettime,
+ field->ret.overrun,
+ field->ret.depth));
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t trace_graph_ret_hex(struct trace_iterator *iter, int flags,
+ struct trace_event *event)
+{
+ struct ftrace_graph_ret_entry *field;
+ struct trace_seq *s = &iter->seq;
+
+ trace_assign_type(field, iter->ent);
+
+ SEQ_PUT_HEX_FIELD_RET(s, field->ret.func);
+ SEQ_PUT_HEX_FIELD_RET(s, field->ret.calltime);
+ SEQ_PUT_HEX_FIELD_RET(s, field->ret.rettime);
+ SEQ_PUT_HEX_FIELD_RET(s, field->ret.overrun);
+ SEQ_PUT_HEX_FIELD_RET(s, field->ret.depth);
+
+ return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t trace_graph_ret_bin(struct trace_iterator *iter, int flags,
+ struct trace_event *event)
+{
+ struct ftrace_graph_ret_entry *field;
+ struct trace_seq *s = &iter->seq;
+
+ trace_assign_type(field, iter->ent);
+
+ SEQ_PUT_FIELD_RET(s, field->ret.func);
+ SEQ_PUT_FIELD_RET(s, field->ret.calltime);
+ SEQ_PUT_FIELD_RET(s, field->ret.rettime);
+ SEQ_PUT_FIELD_RET(s, field->ret.overrun);
+ SEQ_PUT_FIELD_RET(s, field->ret.depth);
+
+ return TRACE_TYPE_HANDLED;
+}
+
+static struct trace_event_functions trace_graph_ret_funcs = {
+ .trace = trace_graph_ret_trace,
+ .raw = trace_graph_ret_raw,
+ .hex = trace_graph_ret_hex,
+ .binary = trace_graph_ret_bin,
+};
+
+static struct trace_event trace_graph_ret_event = {
+ .type = TRACE_GRAPH_RET,
+ .funcs = &trace_graph_ret_funcs,
+};
+
/* TRACE_CTX an TRACE_WAKE */
static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
char *delim)
@@ -1425,6 +1601,8 @@ static struct trace_event trace_print_event = {
static struct trace_event *events[] __initdata = {
&trace_fn_event,
+ &trace_graph_ent_event,
+ &trace_graph_ret_event,
&trace_ctx_event,
&trace_wake_event,
&trace_stack_event,
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 4431610f049a..68fbd3f169f1 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -45,6 +45,11 @@ static DEFINE_PER_CPU(unsigned long, soft_lockup_hrtimer_cnt);
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);
+#endif
+#ifdef CONFIG_HARDLOCKUP_DETECTOR_OTHER_CPU
+static cpumask_t __read_mostly watchdog_cpus;
+#endif
+#ifdef CONFIG_HARDLOCKUP_DETECTOR_NMI
static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);
#endif
@@ -178,7 +183,7 @@ void touch_softlockup_watchdog_sync(void)
__raw_get_cpu_var(watchdog_touch_ts) = 0;
}
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
+#ifdef CONFIG_HARDLOCKUP_DETECTOR_NMI
/* watchdog detector functions */
static int is_hardlockup(void)
{
@@ -192,6 +197,76 @@ static int is_hardlockup(void)
}
#endif
+#ifdef CONFIG_HARDLOCKUP_DETECTOR_OTHER_CPU
+static unsigned int watchdog_next_cpu(unsigned int cpu)
+{
+ cpumask_t cpus = watchdog_cpus;
+ unsigned int next_cpu;
+
+ next_cpu = cpumask_next(cpu, &cpus);
+ if (next_cpu >= nr_cpu_ids)
+ next_cpu = cpumask_first(&cpus);
+
+ if (next_cpu == cpu)
+ return nr_cpu_ids;
+
+ return next_cpu;
+}
+
+static int is_hardlockup_other_cpu(unsigned int cpu)
+{
+ unsigned long hrint = per_cpu(hrtimer_interrupts, cpu);
+
+ if (per_cpu(hrtimer_interrupts_saved, cpu) == hrint)
+ return 1;
+
+ per_cpu(hrtimer_interrupts_saved, cpu) = hrint;
+ return 0;
+}
+
+static void watchdog_check_hardlockup_other_cpu(void)
+{
+ unsigned int next_cpu;
+
+ /*
+ * Test for hardlockups every 3 samples. The sample period is
+ * watchdog_thresh * 2 / 5, so 3 samples gets us back to slightly over
+ * watchdog_thresh (over by 20%).
+ */
+ if (__this_cpu_read(hrtimer_interrupts) % 3 != 0)
+ return;
+
+ /* check for a hardlockup on the next cpu */
+ next_cpu = watchdog_next_cpu(smp_processor_id());
+ if (next_cpu >= nr_cpu_ids)
+ return;
+
+ smp_rmb();
+
+ if (per_cpu(watchdog_nmi_touch, next_cpu) == true) {
+ per_cpu(watchdog_nmi_touch, next_cpu) = false;
+ return;
+ }
+
+ if (is_hardlockup_other_cpu(next_cpu)) {
+ /* only warn once */
+ if (per_cpu(hard_watchdog_warn, next_cpu) == true)
+ return;
+
+ if (hardlockup_panic)
+ panic("Watchdog detected hard LOCKUP on cpu %u", next_cpu);
+ else
+ WARN(1, "Watchdog detected hard LOCKUP on cpu %u", next_cpu);
+
+ per_cpu(hard_watchdog_warn, next_cpu) = true;
+ } else {
+ per_cpu(hard_watchdog_warn, next_cpu) = false;
+ }
+}
+#else
+static inline void watchdog_check_hardlockup_other_cpu(void) { return; }
+#endif
+
static int is_softlockup(unsigned long touch_ts)
{
unsigned long now = get_timestamp();
@@ -203,7 +278,7 @@ static int is_softlockup(unsigned long touch_ts)
return 0;
}
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
+#ifdef CONFIG_HARDLOCKUP_DETECTOR_NMI
static struct perf_event_attr wd_hw_attr = {
.type = PERF_TYPE_HARDWARE,
@@ -251,7 +326,7 @@ static void watchdog_overflow_callback(struct perf_event *event,
__this_cpu_write(hard_watchdog_warn, false);
return;
}
-#endif /* CONFIG_HARDLOCKUP_DETECTOR */
+#endif /* CONFIG_HARDLOCKUP_DETECTOR_NMI */
static void watchdog_interrupt_count(void)
{
@@ -271,6 +346,9 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
/* kick the hardlockup detector */
watchdog_interrupt_count();
+ /* test for hardlockups on the next cpu */
+ watchdog_check_hardlockup_other_cpu();
+
/* kick the softlockup detector */
wake_up_process(__this_cpu_read(softlockup_watchdog));
@@ -395,7 +473,7 @@ static void watchdog(unsigned int cpu)
__touch_watchdog();
}
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
+#ifdef CONFIG_HARDLOCKUP_DETECTOR_NMI
/*
* People like the simple clean cpu node info on boot.
* Reduce the watchdog noise by only printing messages
@@ -471,9 +549,44 @@ static void watchdog_nmi_disable(unsigned int cpu)
return;
}
#else
+#ifdef CONFIG_HARDLOCKUP_DETECTOR_OTHER_CPU
+static int watchdog_nmi_enable(unsigned int cpu)
+{
+ /*
+ * The new cpu will be marked online before the first hrtimer interrupt
+ * runs on it. If another cpu tests for a hardlockup on the new cpu
+ * before it has run its first hrtimer, it will get a false positive.
+ * Touch the watchdog on the new cpu to delay the first check for at
+ * least 3 sampling periods to guarantee one hrtimer has run on the new
+ * cpu.
+ */
+ per_cpu(watchdog_nmi_touch, cpu) = true;
+ smp_wmb();
+ cpumask_set_cpu(cpu, &watchdog_cpus);
+ return 0;
+}
+
+static void watchdog_nmi_disable(unsigned int cpu)
+{
+ unsigned int next_cpu = watchdog_next_cpu(cpu);
+
+ /*
+ * Offlining this cpu will cause the cpu before this one to start
+ * checking the one after this one. If this cpu just finished checking
+ * the next cpu and updating hrtimer_interrupts_saved, and then the
+ * previous cpu checks it within one sample period, it will trigger a
+ * false positive. Touch the watchdog on the next cpu to prevent it.
+ */
+ if (next_cpu < nr_cpu_ids)
+ per_cpu(watchdog_nmi_touch, next_cpu) = true;
+ smp_wmb();
+ cpumask_clear_cpu(cpu, &watchdog_cpus);
+}
+#else
static int watchdog_nmi_enable(unsigned int cpu) { return 0; }
static void watchdog_nmi_disable(unsigned int cpu) { return; }
-#endif /* CONFIG_HARDLOCKUP_DETECTOR */
+#endif /* CONFIG_HARDLOCKUP_DETECTOR_OTHER_CPU */
+#endif /* CONFIG_HARDLOCKUP_DETECTOR_NMI */
static struct smp_hotplug_thread watchdog_threads = {
.store = &softlockup_watchdog,
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-16 20:53:50 +0000