kernel-ark/drivers/char/sysrq.c
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00

616 lines
15 KiB
C

/* -*- linux-c -*-
*
* $Id: sysrq.c,v 1.15 1998/08/23 14:56:41 mj Exp $
*
* Linux Magic System Request Key Hacks
*
* (c) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
* based on ideas by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>
*
* (c) 2000 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
* overhauled to use key registration
* based upon discusions in irc://irc.openprojects.net/#kernelnewbies
*/
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/tty.h>
#include <linux/mount.h>
#include <linux/kdev_t.h>
#include <linux/major.h>
#include <linux/reboot.h>
#include <linux/sysrq.h>
#include <linux/kbd_kern.h>
#include <linux/proc_fs.h>
#include <linux/nmi.h>
#include <linux/quotaops.h>
#include <linux/perf_event.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/suspend.h>
#include <linux/writeback.h>
#include <linux/buffer_head.h> /* for fsync_bdev() */
#include <linux/swap.h>
#include <linux/spinlock.h>
#include <linux/vt_kern.h>
#include <linux/workqueue.h>
#include <linux/hrtimer.h>
#include <linux/oom.h>
#include <linux/slab.h>
#include <asm/ptrace.h>
#include <asm/irq_regs.h>
/* Whether we react on sysrq keys or just ignore them */
int __read_mostly __sysrq_enabled = 1;
static int __read_mostly sysrq_always_enabled;
int sysrq_on(void)
{
return __sysrq_enabled || sysrq_always_enabled;
}
/*
* A value of 1 means 'all', other nonzero values are an op mask:
*/
static inline int sysrq_on_mask(int mask)
{
return sysrq_always_enabled || __sysrq_enabled == 1 ||
(__sysrq_enabled & mask);
}
static int __init sysrq_always_enabled_setup(char *str)
{
sysrq_always_enabled = 1;
printk(KERN_INFO "debug: sysrq always enabled.\n");
return 1;
}
__setup("sysrq_always_enabled", sysrq_always_enabled_setup);
static void sysrq_handle_loglevel(int key, struct tty_struct *tty)
{
int i;
i = key - '0';
console_loglevel = 7;
printk("Loglevel set to %d\n", i);
console_loglevel = i;
}
static struct sysrq_key_op sysrq_loglevel_op = {
.handler = sysrq_handle_loglevel,
.help_msg = "loglevel(0-9)",
.action_msg = "Changing Loglevel",
.enable_mask = SYSRQ_ENABLE_LOG,
};
#ifdef CONFIG_VT
static void sysrq_handle_SAK(int key, struct tty_struct *tty)
{
struct work_struct *SAK_work = &vc_cons[fg_console].SAK_work;
schedule_work(SAK_work);
}
static struct sysrq_key_op sysrq_SAK_op = {
.handler = sysrq_handle_SAK,
.help_msg = "saK",
.action_msg = "SAK",
.enable_mask = SYSRQ_ENABLE_KEYBOARD,
};
#else
#define sysrq_SAK_op (*(struct sysrq_key_op *)0)
#endif
#ifdef CONFIG_VT
static void sysrq_handle_unraw(int key, struct tty_struct *tty)
{
struct kbd_struct *kbd = &kbd_table[fg_console];
if (kbd)
kbd->kbdmode = default_utf8 ? VC_UNICODE : VC_XLATE;
}
static struct sysrq_key_op sysrq_unraw_op = {
.handler = sysrq_handle_unraw,
.help_msg = "unRaw",
.action_msg = "Keyboard mode set to system default",
.enable_mask = SYSRQ_ENABLE_KEYBOARD,
};
#else
#define sysrq_unraw_op (*(struct sysrq_key_op *)0)
#endif /* CONFIG_VT */
static void sysrq_handle_crash(int key, struct tty_struct *tty)
{
char *killer = NULL;
panic_on_oops = 1; /* force panic */
wmb();
*killer = 1;
}
static struct sysrq_key_op sysrq_crash_op = {
.handler = sysrq_handle_crash,
.help_msg = "Crash",
.action_msg = "Trigger a crash",
.enable_mask = SYSRQ_ENABLE_DUMP,
};
static void sysrq_handle_reboot(int key, struct tty_struct *tty)
{
lockdep_off();
local_irq_enable();
emergency_restart();
}
static struct sysrq_key_op sysrq_reboot_op = {
.handler = sysrq_handle_reboot,
.help_msg = "reBoot",
.action_msg = "Resetting",
.enable_mask = SYSRQ_ENABLE_BOOT,
};
static void sysrq_handle_sync(int key, struct tty_struct *tty)
{
emergency_sync();
}
static struct sysrq_key_op sysrq_sync_op = {
.handler = sysrq_handle_sync,
.help_msg = "Sync",
.action_msg = "Emergency Sync",
.enable_mask = SYSRQ_ENABLE_SYNC,
};
static void sysrq_handle_show_timers(int key, struct tty_struct *tty)
{
sysrq_timer_list_show();
}
static struct sysrq_key_op sysrq_show_timers_op = {
.handler = sysrq_handle_show_timers,
.help_msg = "show-all-timers(Q)",
.action_msg = "Show clockevent devices & pending hrtimers (no others)",
};
static void sysrq_handle_mountro(int key, struct tty_struct *tty)
{
emergency_remount();
}
static struct sysrq_key_op sysrq_mountro_op = {
.handler = sysrq_handle_mountro,
.help_msg = "Unmount",
.action_msg = "Emergency Remount R/O",
.enable_mask = SYSRQ_ENABLE_REMOUNT,
};
#ifdef CONFIG_LOCKDEP
static void sysrq_handle_showlocks(int key, struct tty_struct *tty)
{
debug_show_all_locks();
}
static struct sysrq_key_op sysrq_showlocks_op = {
.handler = sysrq_handle_showlocks,
.help_msg = "show-all-locks(D)",
.action_msg = "Show Locks Held",
};
#else
#define sysrq_showlocks_op (*(struct sysrq_key_op *)0)
#endif
#ifdef CONFIG_SMP
static DEFINE_SPINLOCK(show_lock);
static void showacpu(void *dummy)
{
unsigned long flags;
/* Idle CPUs have no interesting backtrace. */
if (idle_cpu(smp_processor_id()))
return;
spin_lock_irqsave(&show_lock, flags);
printk(KERN_INFO "CPU%d:\n", smp_processor_id());
show_stack(NULL, NULL);
spin_unlock_irqrestore(&show_lock, flags);
}
static void sysrq_showregs_othercpus(struct work_struct *dummy)
{
smp_call_function(showacpu, NULL, 0);
}
static DECLARE_WORK(sysrq_showallcpus, sysrq_showregs_othercpus);
static void sysrq_handle_showallcpus(int key, struct tty_struct *tty)
{
/*
* Fall back to the workqueue based printing if the
* backtrace printing did not succeed or the
* architecture has no support for it:
*/
if (!trigger_all_cpu_backtrace()) {
struct pt_regs *regs = get_irq_regs();
if (regs) {
printk(KERN_INFO "CPU%d:\n", smp_processor_id());
show_regs(regs);
}
schedule_work(&sysrq_showallcpus);
}
}
static struct sysrq_key_op sysrq_showallcpus_op = {
.handler = sysrq_handle_showallcpus,
.help_msg = "show-backtrace-all-active-cpus(L)",
.action_msg = "Show backtrace of all active CPUs",
.enable_mask = SYSRQ_ENABLE_DUMP,
};
#endif
static void sysrq_handle_showregs(int key, struct tty_struct *tty)
{
struct pt_regs *regs = get_irq_regs();
if (regs)
show_regs(regs);
perf_event_print_debug();
}
static struct sysrq_key_op sysrq_showregs_op = {
.handler = sysrq_handle_showregs,
.help_msg = "show-registers(P)",
.action_msg = "Show Regs",
.enable_mask = SYSRQ_ENABLE_DUMP,
};
static void sysrq_handle_showstate(int key, struct tty_struct *tty)
{
show_state();
}
static struct sysrq_key_op sysrq_showstate_op = {
.handler = sysrq_handle_showstate,
.help_msg = "show-task-states(T)",
.action_msg = "Show State",
.enable_mask = SYSRQ_ENABLE_DUMP,
};
static void sysrq_handle_showstate_blocked(int key, struct tty_struct *tty)
{
show_state_filter(TASK_UNINTERRUPTIBLE);
}
static struct sysrq_key_op sysrq_showstate_blocked_op = {
.handler = sysrq_handle_showstate_blocked,
.help_msg = "show-blocked-tasks(W)",
.action_msg = "Show Blocked State",
.enable_mask = SYSRQ_ENABLE_DUMP,
};
#ifdef CONFIG_TRACING
#include <linux/ftrace.h>
static void sysrq_ftrace_dump(int key, struct tty_struct *tty)
{
ftrace_dump();
}
static struct sysrq_key_op sysrq_ftrace_dump_op = {
.handler = sysrq_ftrace_dump,
.help_msg = "dump-ftrace-buffer(Z)",
.action_msg = "Dump ftrace buffer",
.enable_mask = SYSRQ_ENABLE_DUMP,
};
#else
#define sysrq_ftrace_dump_op (*(struct sysrq_key_op *)0)
#endif
static void sysrq_handle_showmem(int key, struct tty_struct *tty)
{
show_mem();
}
static struct sysrq_key_op sysrq_showmem_op = {
.handler = sysrq_handle_showmem,
.help_msg = "show-memory-usage(M)",
.action_msg = "Show Memory",
.enable_mask = SYSRQ_ENABLE_DUMP,
};
/*
* Signal sysrq helper function. Sends a signal to all user processes.
*/
static void send_sig_all(int sig)
{
struct task_struct *p;
for_each_process(p) {
if (p->mm && !is_global_init(p))
/* Not swapper, init nor kernel thread */
force_sig(sig, p);
}
}
static void sysrq_handle_term(int key, struct tty_struct *tty)
{
send_sig_all(SIGTERM);
console_loglevel = 8;
}
static struct sysrq_key_op sysrq_term_op = {
.handler = sysrq_handle_term,
.help_msg = "terminate-all-tasks(E)",
.action_msg = "Terminate All Tasks",
.enable_mask = SYSRQ_ENABLE_SIGNAL,
};
static void moom_callback(struct work_struct *ignored)
{
out_of_memory(node_zonelist(0, GFP_KERNEL), GFP_KERNEL, 0, NULL);
}
static DECLARE_WORK(moom_work, moom_callback);
static void sysrq_handle_moom(int key, struct tty_struct *tty)
{
schedule_work(&moom_work);
}
static struct sysrq_key_op sysrq_moom_op = {
.handler = sysrq_handle_moom,
.help_msg = "memory-full-oom-kill(F)",
.action_msg = "Manual OOM execution",
.enable_mask = SYSRQ_ENABLE_SIGNAL,
};
#ifdef CONFIG_BLOCK
static void sysrq_handle_thaw(int key, struct tty_struct *tty)
{
emergency_thaw_all();
}
static struct sysrq_key_op sysrq_thaw_op = {
.handler = sysrq_handle_thaw,
.help_msg = "thaw-filesystems(J)",
.action_msg = "Emergency Thaw of all frozen filesystems",
.enable_mask = SYSRQ_ENABLE_SIGNAL,
};
#endif
static void sysrq_handle_kill(int key, struct tty_struct *tty)
{
send_sig_all(SIGKILL);
console_loglevel = 8;
}
static struct sysrq_key_op sysrq_kill_op = {
.handler = sysrq_handle_kill,
.help_msg = "kill-all-tasks(I)",
.action_msg = "Kill All Tasks",
.enable_mask = SYSRQ_ENABLE_SIGNAL,
};
static void sysrq_handle_unrt(int key, struct tty_struct *tty)
{
normalize_rt_tasks();
}
static struct sysrq_key_op sysrq_unrt_op = {
.handler = sysrq_handle_unrt,
.help_msg = "nice-all-RT-tasks(N)",
.action_msg = "Nice All RT Tasks",
.enable_mask = SYSRQ_ENABLE_RTNICE,
};
/* Key Operations table and lock */
static DEFINE_SPINLOCK(sysrq_key_table_lock);
static struct sysrq_key_op *sysrq_key_table[36] = {
&sysrq_loglevel_op, /* 0 */
&sysrq_loglevel_op, /* 1 */
&sysrq_loglevel_op, /* 2 */
&sysrq_loglevel_op, /* 3 */
&sysrq_loglevel_op, /* 4 */
&sysrq_loglevel_op, /* 5 */
&sysrq_loglevel_op, /* 6 */
&sysrq_loglevel_op, /* 7 */
&sysrq_loglevel_op, /* 8 */
&sysrq_loglevel_op, /* 9 */
/*
* a: Don't use for system provided sysrqs, it is handled specially on
* sparc and will never arrive.
*/
NULL, /* a */
&sysrq_reboot_op, /* b */
&sysrq_crash_op, /* c & ibm_emac driver debug */
&sysrq_showlocks_op, /* d */
&sysrq_term_op, /* e */
&sysrq_moom_op, /* f */
/* g: May be registered for the kernel debugger */
NULL, /* g */
NULL, /* h - reserved for help */
&sysrq_kill_op, /* i */
#ifdef CONFIG_BLOCK
&sysrq_thaw_op, /* j */
#else
NULL, /* j */
#endif
&sysrq_SAK_op, /* k */
#ifdef CONFIG_SMP
&sysrq_showallcpus_op, /* l */
#else
NULL, /* l */
#endif
&sysrq_showmem_op, /* m */
&sysrq_unrt_op, /* n */
/* o: This will often be registered as 'Off' at init time */
NULL, /* o */
&sysrq_showregs_op, /* p */
&sysrq_show_timers_op, /* q */
&sysrq_unraw_op, /* r */
&sysrq_sync_op, /* s */
&sysrq_showstate_op, /* t */
&sysrq_mountro_op, /* u */
/* v: May be registered for frame buffer console restore */
NULL, /* v */
&sysrq_showstate_blocked_op, /* w */
/* x: May be registered on ppc/powerpc for xmon */
NULL, /* x */
/* y: May be registered on sparc64 for global register dump */
NULL, /* y */
&sysrq_ftrace_dump_op, /* z */
};
/* key2index calculation, -1 on invalid index */
static int sysrq_key_table_key2index(int key)
{
int retval;
if ((key >= '0') && (key <= '9'))
retval = key - '0';
else if ((key >= 'a') && (key <= 'z'))
retval = key + 10 - 'a';
else
retval = -1;
return retval;
}
/*
* get and put functions for the table, exposed to modules.
*/
struct sysrq_key_op *__sysrq_get_key_op(int key)
{
struct sysrq_key_op *op_p = NULL;
int i;
i = sysrq_key_table_key2index(key);
if (i != -1)
op_p = sysrq_key_table[i];
return op_p;
}
static void __sysrq_put_key_op(int key, struct sysrq_key_op *op_p)
{
int i = sysrq_key_table_key2index(key);
if (i != -1)
sysrq_key_table[i] = op_p;
}
/*
* This is the non-locking version of handle_sysrq. It must/can only be called
* by sysrq key handlers, as they are inside of the lock
*/
void __handle_sysrq(int key, struct tty_struct *tty, int check_mask)
{
struct sysrq_key_op *op_p;
int orig_log_level;
int i;
unsigned long flags;
spin_lock_irqsave(&sysrq_key_table_lock, flags);
/*
* Raise the apparent loglevel to maximum so that the sysrq header
* is shown to provide the user with positive feedback. We do not
* simply emit this at KERN_EMERG as that would change message
* routing in the consumers of /proc/kmsg.
*/
orig_log_level = console_loglevel;
console_loglevel = 7;
printk(KERN_INFO "SysRq : ");
op_p = __sysrq_get_key_op(key);
if (op_p) {
/*
* Should we check for enabled operations (/proc/sysrq-trigger
* should not) and is the invoked operation enabled?
*/
if (!check_mask || sysrq_on_mask(op_p->enable_mask)) {
printk("%s\n", op_p->action_msg);
console_loglevel = orig_log_level;
op_p->handler(key, tty);
} else {
printk("This sysrq operation is disabled.\n");
}
} else {
printk("HELP : ");
/* Only print the help msg once per handler */
for (i = 0; i < ARRAY_SIZE(sysrq_key_table); i++) {
if (sysrq_key_table[i]) {
int j;
for (j = 0; sysrq_key_table[i] !=
sysrq_key_table[j]; j++)
;
if (j != i)
continue;
printk("%s ", sysrq_key_table[i]->help_msg);
}
}
printk("\n");
console_loglevel = orig_log_level;
}
spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
}
/*
* This function is called by the keyboard handler when SysRq is pressed
* and any other keycode arrives.
*/
void handle_sysrq(int key, struct tty_struct *tty)
{
if (sysrq_on())
__handle_sysrq(key, tty, 1);
}
EXPORT_SYMBOL(handle_sysrq);
static int __sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p,
struct sysrq_key_op *remove_op_p)
{
int retval;
unsigned long flags;
spin_lock_irqsave(&sysrq_key_table_lock, flags);
if (__sysrq_get_key_op(key) == remove_op_p) {
__sysrq_put_key_op(key, insert_op_p);
retval = 0;
} else {
retval = -1;
}
spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
return retval;
}
int register_sysrq_key(int key, struct sysrq_key_op *op_p)
{
return __sysrq_swap_key_ops(key, op_p, NULL);
}
EXPORT_SYMBOL(register_sysrq_key);
int unregister_sysrq_key(int key, struct sysrq_key_op *op_p)
{
return __sysrq_swap_key_ops(key, NULL, op_p);
}
EXPORT_SYMBOL(unregister_sysrq_key);
#ifdef CONFIG_PROC_FS
/*
* writing 'C' to /proc/sysrq-trigger is like sysrq-C
*/
static ssize_t write_sysrq_trigger(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
if (count) {
char c;
if (get_user(c, buf))
return -EFAULT;
__handle_sysrq(c, NULL, 0);
}
return count;
}
static const struct file_operations proc_sysrq_trigger_operations = {
.write = write_sysrq_trigger,
};
static int __init sysrq_init(void)
{
proc_create("sysrq-trigger", S_IWUSR, NULL, &proc_sysrq_trigger_operations);
return 0;
}
module_init(sysrq_init);
#endif