Merge git://oss.sgi.com:8090/xfs/xfs-2.6

[linux-drm-fsl-dcu.git] / drivers / char / sysrq.c

diff --git a/drivers/char/sysrq.c b/drivers/char/sysrq.c
index 5f49280779fb0a98c567ec12e2350a634d95eece..3757610b7835d4952e992563821293e6cc781fcd 100644 (file)
--- a/drivers/char/sysrq.c
+++ b/drivers/char/sysrq.c
@@ -41,7 +41,34 @@
 #include <asm/irq_regs.h>
 
 /* Whether we react on sysrq keys or just ignore them */
-int sysrq_enabled = 1;
+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)
 {
@@ -61,9 +88,9 @@ static struct sysrq_key_op sysrq_loglevel_op = {
 #ifdef CONFIG_VT
 static void sysrq_handle_SAK(int key, struct tty_struct *tty)
 {
-       if (tty)
-               do_SAK(tty);
-       reset_vc(vc_cons[fg_console].d);
+       struct work_struct *SAK_work = &vc_cons[fg_console].SAK_work;
+       PREPARE_WORK(SAK_work, vc_SAK);
+       schedule_work(SAK_work);
 }
 static struct sysrq_key_op sysrq_SAK_op = {
        .handler        = sysrq_handle_SAK,
@@ -182,6 +209,18 @@ static struct sysrq_key_op sysrq_showstate_op = {
        .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",
+       .action_msg     = "Show Blocked State",
+       .enable_mask    = SYSRQ_ENABLE_DUMP,
+};
+
+
 static void sysrq_handle_showmem(int key, struct tty_struct *tty)
 {
        show_mem();
@@ -219,13 +258,13 @@ static struct sysrq_key_op sysrq_term_op = {
        .enable_mask    = SYSRQ_ENABLE_SIGNAL,
 };
 
-static void moom_callback(void *ignored)
+static void moom_callback(struct work_struct *ignored)
 {
        out_of_memory(&NODE_DATA(0)->node_zonelists[ZONE_NORMAL],
                        GFP_KERNEL, 0);
 }
 
-static DECLARE_WORK(moom_work, moom_callback, NULL);
+static DECLARE_WORK(moom_work, moom_callback);
 
 static void sysrq_handle_moom(int key, struct tty_struct *tty)
 {
@@ -276,15 +315,16 @@ static struct sysrq_key_op *sysrq_key_table[36] = {
        &sysrq_loglevel_op,             /* 9 */
 
        /*
-        * Don't use for system provided sysrqs, it is handled specially on
-        * sparc and will never arrive
+        * 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_crashdump_op,            /* c */
+       &sysrq_crashdump_op,            /* c & ibm_emac driver debug */
        &sysrq_showlocks_op,            /* d */
        &sysrq_term_op,                 /* e */
        &sysrq_moom_op,                 /* f */
+       /* g: May be registered by ppc for kgdb */
        NULL,                           /* g */
        NULL,                           /* h */
        &sysrq_kill_op,                 /* i */
@@ -293,17 +333,18 @@ static struct sysrq_key_op *sysrq_key_table[36] = {
        NULL,                           /* l */
        &sysrq_showmem_op,              /* m */
        &sysrq_unrt_op,                 /* n */
-       /* This will often be registered as 'Off' at init time */
+       /* o: This will often be registered as 'Off' at init time */
        NULL,                           /* o */
        &sysrq_showregs_op,             /* p */
        NULL,                           /* q */
-       &sysrq_unraw_op,                        /* r */
+       &sysrq_unraw_op,                /* r */
        &sysrq_sync_op,                 /* s */
        &sysrq_showstate_op,            /* t */
        &sysrq_mountro_op,              /* u */
-       /* May be assigned at init time by SMP VOYAGER */
+       /* v: May be registered at init time by SMP VOYAGER */
        NULL,                           /* v */
-       NULL,                           /* w */
+       &sysrq_showstate_blocked_op,    /* w */
+       /* x: May be registered on ppc/powerpc for xmon */
        NULL,                           /* x */
        NULL,                           /* y */
        NULL                            /* z */
@@ -367,8 +408,7 @@ void __handle_sysrq(int key, struct tty_struct *tty, int check_mask)
                 * Should we check for enabled operations (/proc/sysrq-trigger
                 * should not) and is the invoked operation enabled?
                 */
-               if (!check_mask || sysrq_enabled == 1 ||
-                   (sysrq_enabled & op_p->enable_mask)) {
+               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);
@@ -402,9 +442,8 @@ void __handle_sysrq(int key, struct tty_struct *tty, int check_mask)
  */
 void handle_sysrq(int key, struct tty_struct *tty)
 {
-       if (!sysrq_enabled)
-               return;
-       __handle_sysrq(key, tty, 1);
+       if (sysrq_on())
+               __handle_sysrq(key, tty, 1);
 }
 EXPORT_SYMBOL(handle_sysrq);