Merge branch 'akpm' (Andrew's patch-bomb)

Merge third batch of patches from Andrew Morton:
 - Some MM stragglers
 - core SMP library cleanups (on_each_cpu_mask)
 - Some IPI optimisations
 - kexec
 - kdump
 - IPMI
 - the radix-tree iterator work
 - various other misc bits.

 "That'll do for -rc1.  I still have ~10 patches for 3.4, will send
  those along when they've baked a little more."

* emailed from Andrew Morton <akpm@linux-foundation.org>: (35 commits)
  backlight: fix typo in tosa_lcd.c
  crc32: add help text for the algorithm select option
  mm: move hugepage test examples to tools/testing/selftests/vm
  mm: move slabinfo.c to tools/vm
  mm: move page-types.c from Documentation to tools/vm
  selftests/Makefile: make `run_tests' depend on `all'
  selftests: launch individual selftests from the main Makefile
  radix-tree: use iterators in find_get_pages* functions
  radix-tree: rewrite gang lookup using iterator
  radix-tree: introduce bit-optimized iterator
  fs/proc/namespaces.c: prevent crash when ns_entries[] is empty
  nbd: rename the nbd_device variable from lo to nbd
  pidns: add reboot_pid_ns() to handle the reboot syscall
  sysctl: use bitmap library functions
  ipmi: use locks on watchdog timeout set on reboot
  ipmi: simplify locking
  ipmi: fix message handling during panics
  ipmi: use a tasklet for handling received messages
  ipmi: increase KCS timeouts
  ipmi: decrease the IPMI message transaction time in interrupt mode
  ...

kernel/kexec.c

@@ -1358,6 +1358,10 @@ static int __init parse_crashkernel_simple(char 		*cmdline,
 
 	if (*cur == '@')
 		*crash_base = memparse(cur+1, &cur);
+	else if (*cur != ' ' && *cur != '\0') {
+		pr_warning("crashkernel: unrecognized char\n");
+		return -EINVAL;
+	}
 
 	return 0;
 }
@@ -1461,7 +1465,9 @@ static int __init crash_save_vmcoreinfo_init(void)
 
 	VMCOREINFO_SYMBOL(init_uts_ns);
 	VMCOREINFO_SYMBOL(node_online_map);
+#ifdef CONFIG_MMU
 	VMCOREINFO_SYMBOL(swapper_pg_dir);
+#endif
 	VMCOREINFO_SYMBOL(_stext);
 	VMCOREINFO_SYMBOL(vmlist);
 

kernel/pid_namespace.c

@@ -15,6 +15,7 @@
 #include <linux/acct.h>
 #include <linux/slab.h>
 #include <linux/proc_fs.h>
+#include <linux/reboot.h>
 
 #define BITS_PER_PAGE		(PAGE_SIZE*8)
 
@@ -183,6 +184,9 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns)
 		rc = sys_wait4(-1, NULL, __WALL, NULL);
 	} while (rc != -ECHILD);
 
+	if (pid_ns->reboot)
+		current->signal->group_exit_code = pid_ns->reboot;
+
 	acct_exit_ns(pid_ns);
 	return;
 }
@@ -217,6 +221,35 @@ static struct ctl_table pid_ns_ctl_table[] = {
 
 static struct ctl_path kern_path[] = { { .procname = "kernel", }, { } };
 
+int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
+{
+	if (pid_ns == &init_pid_ns)
+		return 0;
+
+	switch (cmd) {
+	case LINUX_REBOOT_CMD_RESTART2:
+	case LINUX_REBOOT_CMD_RESTART:
+		pid_ns->reboot = SIGHUP;
+		break;
+
+	case LINUX_REBOOT_CMD_POWER_OFF:
+	case LINUX_REBOOT_CMD_HALT:
+		pid_ns->reboot = SIGINT;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	read_lock(&tasklist_lock);
+	force_sig(SIGKILL, pid_ns->child_reaper);
+	read_unlock(&tasklist_lock);
+
+	do_exit(0);
+
+	/* Not reached */
+	return 0;
+}
+
 static __init int pid_namespaces_init(void)
 {
 	pid_ns_cachep = KMEM_CACHE(pid_namespace, SLAB_PANIC);

kernel/smp.c

@@ -701,3 +701,93 @@ int on_each_cpu(void (*func) (void *info), void *info, int wait)
 	return ret;
 }
 EXPORT_SYMBOL(on_each_cpu);
+
+/**
+ * on_each_cpu_mask(): Run a function on processors specified by
+ * cpumask, which may include the local processor.
+ * @mask: The set of cpus to run on (only runs on online subset).
+ * @func: The function to run. This must be fast and non-blocking.
+ * @info: An arbitrary pointer to pass to the function.
+ * @wait: If true, wait (atomically) until function has completed
+ *        on other CPUs.
+ *
+ * If @wait is true, then returns once @func has returned.
+ *
+ * You must not call this function with disabled interrupts or
+ * from a hardware interrupt handler or from a bottom half handler.
+ */
+void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
+			void *info, bool wait)
+{
+	int cpu = get_cpu();
+
+	smp_call_function_many(mask, func, info, wait);
+	if (cpumask_test_cpu(cpu, mask)) {
+		local_irq_disable();
+		func(info);
+		local_irq_enable();
+	}
+	put_cpu();
+}
+EXPORT_SYMBOL(on_each_cpu_mask);
+
+/*
+ * on_each_cpu_cond(): Call a function on each processor for which
+ * the supplied function cond_func returns true, optionally waiting
+ * for all the required CPUs to finish. This may include the local
+ * processor.
+ * @cond_func:	A callback function that is passed a cpu id and
+ *		the the info parameter. The function is called
+ *		with preemption disabled. The function should
+ *		return a blooean value indicating whether to IPI
+ *		the specified CPU.
+ * @func:	The function to run on all applicable CPUs.
+ *		This must be fast and non-blocking.
+ * @info:	An arbitrary pointer to pass to both functions.
+ * @wait:	If true, wait (atomically) until function has
+ *		completed on other CPUs.
+ * @gfp_flags:	GFP flags to use when allocating the cpumask
+ *		used internally by the function.
+ *
+ * The function might sleep if the GFP flags indicates a non
+ * atomic allocation is allowed.
+ *
+ * Preemption is disabled to protect against CPUs going offline but not online.
+ * CPUs going online during the call will not be seen or sent an IPI.
+ *
+ * You must not call this function with disabled interrupts or
+ * from a hardware interrupt handler or from a bottom half handler.
+ */
+void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
+			smp_call_func_t func, void *info, bool wait,
+			gfp_t gfp_flags)
+{
+	cpumask_var_t cpus;
+	int cpu, ret;
+
+	might_sleep_if(gfp_flags & __GFP_WAIT);
+
+	if (likely(zalloc_cpumask_var(&cpus, (gfp_flags|__GFP_NOWARN)))) {
+		preempt_disable();
+		for_each_online_cpu(cpu)
+			if (cond_func(cpu, info))
+				cpumask_set_cpu(cpu, cpus);
+		on_each_cpu_mask(cpus, func, info, wait);
+		preempt_enable();
+		free_cpumask_var(cpus);
+	} else {
+		/*
+		 * No free cpumask, bother. No matter, we'll
+		 * just have to IPI them one by one.
+		 */
+		preempt_disable();
+		for_each_online_cpu(cpu)
+			if (cond_func(cpu, info)) {
+				ret = smp_call_function_single(cpu, func,
+								info, wait);
+				WARN_ON_ONCE(!ret);
+			}
+		preempt_enable();
+	}
+}
+EXPORT_SYMBOL(on_each_cpu_cond);

kernel/sys.c

@@ -444,6 +444,15 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
 	                magic2 != LINUX_REBOOT_MAGIC2C))
 		return -EINVAL;
 
+	/*
+	 * If pid namespaces are enabled and the current task is in a child
+	 * pid_namespace, the command is handled by reboot_pid_ns() which will
+	 * call do_exit().
+	 */
+	ret = reboot_pid_ns(task_active_pid_ns(current), cmd);
+	if (ret)
+		return ret;
+
 	/* Instead of trying to make the power_off code look like
 	 * halt when pm_power_off is not set do it the easy way.
 	 */

kernel/sysctl.c

@@ -23,6 +23,7 @@
 #include <linux/swap.h>
 #include <linux/slab.h>
 #include <linux/sysctl.h>
+#include <linux/bitmap.h>
 #include <linux/signal.h>
 #include <linux/printk.h>
 #include <linux/proc_fs.h>
@@ -2395,9 +2396,7 @@ int proc_do_large_bitmap(struct ctl_table *table, int write,
 				}
 			}
 
-			while (val_a <= val_b)
-				set_bit(val_a++, tmp_bitmap);
-
+			bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
 			first = 0;
 			proc_skip_char(&kbuf, &left, '\n');
 		}
@@ -2440,8 +2439,7 @@ int proc_do_large_bitmap(struct ctl_table *table, int write,
 			if (*ppos)
 				bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
 			else
-				memcpy(bitmap, tmp_bitmap,
-					BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
+				bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
 		}
 		kfree(tmp_bitmap);
 		*lenp -= left;