Merge branch 'akpm' (incoming from Andrew)

Merge third batch of fixes from Andrew Morton:
 "Most of the rest.  I still have two large patchsets against AIO and
  IPC, but they're a bit stuck behind other trees and I'm about to
  vanish for six days.

   - random fixlets
   - inotify
   - more of the MM queue
   - show_stack() cleanups
   - DMI update
   - kthread/workqueue things
   - compat cleanups
   - epoll udpates
   - binfmt updates
   - nilfs2
   - hfs
   - hfsplus
   - ptrace
   - kmod
   - coredump
   - kexec
   - rbtree
   - pids
   - pidns
   - pps
   - semaphore tweaks
   - some w1 patches
   - relay updates
   - core Kconfig changes
   - sysrq tweaks"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (109 commits)
  Documentation/sysrq: fix inconstistent help message of sysrq key
  ethernet/emac/sysrq: fix inconstistent help message of sysrq key
  sparc/sysrq: fix inconstistent help message of sysrq key
  powerpc/xmon/sysrq: fix inconstistent help message of sysrq key
  ARM/etm/sysrq: fix inconstistent help message of sysrq key
  power/sysrq: fix inconstistent help message of sysrq key
  kgdb/sysrq: fix inconstistent help message of sysrq key
  lib/decompress.c: fix initconst
  notifier-error-inject: fix module names in Kconfig
  kernel/sys.c: make prctl(PR_SET_MM) generally available
  UAPI: remove empty Kbuild files
  menuconfig: print more info for symbol without prompts
  init/Kconfig: re-order CONFIG_EXPERT options to fix menuconfig display
  kconfig menu: move Virtualization drivers near other virtualization options
  Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
  relay: use macro PAGE_ALIGN instead of FIX_SIZE
  kernel/relay.c: move FIX_SIZE macro into relay.c
  kernel/relay.c: remove unused function argument actor
  drivers/w1/slaves/w1_ds2760.c: fix the error handling in w1_ds2760_add_slave()
  drivers/w1/slaves/w1_ds2781.c: fix the error handling in w1_ds2781_add_slave()
  ...

15 files changed, 109 insertions, 62 deletions

diff --git a/include/linux/cleancache.h b/include/linux/cleancache.h
index 42e55deee75..4ce9056b31a 100644
--- a/include/linux/cleancache.h
+++ b/include/linux/cleancache.h
@@ -33,7 +33,7 @@ struct cleancache_ops {
 	void (*invalidate_fs)(int);
 };
 
-extern struct cleancache_ops
+extern struct cleancache_ops *
 	cleancache_register_ops(struct cleancache_ops *ops);
 extern void __cleancache_init_fs(struct super_block *);
 extern void __cleancache_init_shared_fs(char *, struct super_block *);
@@ -42,9 +42,9 @@ extern void __cleancache_put_page(struct page *);
 extern void __cleancache_invalidate_page(struct address_space *, struct page *);
 extern void __cleancache_invalidate_inode(struct address_space *);
 extern void __cleancache_invalidate_fs(struct super_block *);
-extern int cleancache_enabled;
 
 #ifdef CONFIG_CLEANCACHE
+#define cleancache_enabled (1)
 static inline bool cleancache_fs_enabled(struct page *page)
 {
 	return page->mapping->host->i_sb->cleancache_poolid >= 0;
diff --git a/include/linux/dmi.h b/include/linux/dmi.h
index f156cca25ad..b6eb7a05d58 100644
--- a/include/linux/dmi.h
+++ b/include/linux/dmi.h
@@ -99,6 +99,7 @@ extern const char * dmi_get_system_info(int field);
 extern const struct dmi_device * dmi_find_device(int type, const char *name,
 	const struct dmi_device *from);
 extern void dmi_scan_machine(void);
+extern void dmi_set_dump_stack_arch_desc(void);
 extern bool dmi_get_date(int field, int *yearp, int *monthp, int *dayp);
 extern int dmi_name_in_vendors(const char *str);
 extern int dmi_name_in_serial(const char *str);
@@ -114,6 +115,7 @@ static inline const char * dmi_get_system_info(int field) { return NULL; }
 static inline const struct dmi_device * dmi_find_device(int type, const char *name,
 	const struct dmi_device *from) { return NULL; }
 static inline void dmi_scan_machine(void) { return; }
+static inline void dmi_set_dump_stack_arch_desc(void) { }
 static inline bool dmi_get_date(int field, int *yearp, int *monthp, int *dayp)
 {
 	if (yearp)
diff --git a/include/linux/frontswap.h b/include/linux/frontswap.h
index 30442547b9e..8293262401d 100644
--- a/include/linux/frontswap.h
+++ b/include/linux/frontswap.h
@@ -14,7 +14,7 @@ struct frontswap_ops {
 };
 
 extern bool frontswap_enabled;
-extern struct frontswap_ops
+extern struct frontswap_ops *
 	frontswap_register_ops(struct frontswap_ops *ops);
 extern void frontswap_shrink(unsigned long);
 extern unsigned long frontswap_curr_pages(void);
@@ -22,33 +22,19 @@ extern void frontswap_writethrough(bool);
 #define FRONTSWAP_HAS_EXCLUSIVE_GETS
 extern void frontswap_tmem_exclusive_gets(bool);
 
-extern void __frontswap_init(unsigned type);
+extern bool __frontswap_test(struct swap_info_struct *, pgoff_t);
+extern void __frontswap_init(unsigned type, unsigned long *map);
 extern int __frontswap_store(struct page *page);
 extern int __frontswap_load(struct page *page);
 extern void __frontswap_invalidate_page(unsigned, pgoff_t);
 extern void __frontswap_invalidate_area(unsigned);
 
 #ifdef CONFIG_FRONTSWAP
+#define frontswap_enabled (1)
 
 static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset)
 {
-	bool ret = false;
-
-	if (frontswap_enabled && sis->frontswap_map)
-		ret = test_bit(offset, sis->frontswap_map);
-	return ret;
-}
-
-static inline void frontswap_set(struct swap_info_struct *sis, pgoff_t offset)
-{
-	if (frontswap_enabled && sis->frontswap_map)
-		set_bit(offset, sis->frontswap_map);
-}
-
-static inline void frontswap_clear(struct swap_info_struct *sis, pgoff_t offset)
-{
-	if (frontswap_enabled && sis->frontswap_map)
-		clear_bit(offset, sis->frontswap_map);
+	return __frontswap_test(sis, offset);
 }
 
 static inline void frontswap_map_set(struct swap_info_struct *p,
@@ -71,14 +57,6 @@ static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset)
 	return false;
 }
 
-static inline void frontswap_set(struct swap_info_struct *sis, pgoff_t offset)
-{
-}
-
-static inline void frontswap_clear(struct swap_info_struct *sis, pgoff_t offset)
-{
-}
-
 static inline void frontswap_map_set(struct swap_info_struct *p,
 				     unsigned long *map)
 {
@@ -120,10 +98,10 @@ static inline void frontswap_invalidate_area(unsigned type)
 		__frontswap_invalidate_area(type);
 }
 
-static inline void frontswap_init(unsigned type)
+static inline void frontswap_init(unsigned type, unsigned long *map)
 {
 	if (frontswap_enabled)
-		__frontswap_init(type);
+		__frontswap_init(type, map);
 }
 
 #endif /* _LINUX_FRONTSWAP_H */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2c28271ab9d..17d8b159621 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -675,9 +675,11 @@ static inline loff_t i_size_read(const struct inode *inode)
 static inline void i_size_write(struct inode *inode, loff_t i_size)
 {
 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
+	preempt_disable();
 	write_seqcount_begin(&inode->i_size_seqcount);
 	inode->i_size = i_size;
 	write_seqcount_end(&inode->i_size_seqcount);
+	preempt_enable();
 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
 	preempt_disable();
 	inode->i_size = i_size;
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 2dac79c3919..6d1844f393c 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -798,6 +798,4 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
 #endif
 
-extern int do_sysinfo(struct sysinfo *info);
-
 #endif
diff --git a/include/linux/kmod.h b/include/linux/kmod.h
index 5398d580707..0555cc66a15 100644
--- a/include/linux/kmod.h
+++ b/include/linux/kmod.h
@@ -67,16 +67,15 @@ struct subprocess_info {
 };
 
 extern int
-call_usermodehelper_fns(char *path, char **argv, char **envp, int wait,
-			int (*init)(struct subprocess_info *info, struct cred *new),
-			void (*cleanup)(struct subprocess_info *), void *data);
+call_usermodehelper(char *path, char **argv, char **envp, int wait);
 
-static inline int
-call_usermodehelper(char *path, char **argv, char **envp, int wait)
-{
-	return call_usermodehelper_fns(path, argv, envp, wait,
-				       NULL, NULL, NULL);
-}
+extern struct subprocess_info *
+call_usermodehelper_setup(char *path, char **argv, char **envp, gfp_t gfp_mask,
+			  int (*init)(struct subprocess_info *info, struct cred *new),
+			  void (*cleanup)(struct subprocess_info *), void *data);
+
+extern int
+call_usermodehelper_exec(struct subprocess_info *info, int wait);
 
 extern struct ctl_table usermodehelper_table[];
 
diff --git a/include/linux/kthread.h b/include/linux/kthread.h
index 8d816646f76..7dcef331768 100644
--- a/include/linux/kthread.h
+++ b/include/linux/kthread.h
@@ -43,6 +43,7 @@ bool kthread_should_stop(void);
 bool kthread_should_park(void);
 bool kthread_freezable_should_stop(bool *was_frozen);
 void *kthread_data(struct task_struct *k);
+void *probe_kthread_data(struct task_struct *k);
 int kthread_park(struct task_struct *k);
 void kthread_unpark(struct task_struct *k);
 void kthread_parkme(void);
diff --git a/include/linux/memory.h b/include/linux/memory.h
index 73817af8b48..85c31a8e290 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -137,7 +137,7 @@ enum mem_add_context { BOOT, HOTPLUG };
 #define register_hotmemory_notifier(nb)		register_memory_notifier(nb)
 #define unregister_hotmemory_notifier(nb) 	unregister_memory_notifier(nb)
 #else
-#define hotplug_memory_notifier(fn, pri)	(0)
+#define hotplug_memory_notifier(fn, pri)	({ 0; })
 /* These aren't inline functions due to a GCC bug. */
 #define register_hotmemory_notifier(nb)    ({ (void)(nb); 0; })
 #define unregister_hotmemory_notifier(nb)  ({ (void)(nb); })
diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h
index 215e5e3dda1..8ac32836690 100644
--- a/include/linux/pid_namespace.h
+++ b/include/linux/pid_namespace.h
@@ -13,7 +13,9 @@ struct pidmap {
        void *page;
 };
 
-#define PIDMAP_ENTRIES         ((PID_MAX_LIMIT + 8*PAGE_SIZE - 1)/PAGE_SIZE/8)
+#define BITS_PER_PAGE		(PAGE_SIZE * 8)
+#define BITS_PER_PAGE_MASK	(BITS_PER_PAGE-1)
+#define PIDMAP_ENTRIES		((PID_MAX_LIMIT+BITS_PER_PAGE-1)/BITS_PER_PAGE)
 
 struct bsd_acct_struct;
 
diff --git a/include/linux/printk.h b/include/linux/printk.h
index 4890fe62c01..6af944ab38f 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -145,6 +145,9 @@ extern void wake_up_klogd(void);
 
 void log_buf_kexec_setup(void);
 void __init setup_log_buf(int early);
+void dump_stack_set_arch_desc(const char *fmt, ...);
+void dump_stack_print_info(const char *log_lvl);
+void show_regs_print_info(const char *log_lvl);
 #else
 static inline __printf(1, 0)
 int vprintk(const char *s, va_list args)
@@ -182,6 +185,18 @@ static inline void log_buf_kexec_setup(void)
 static inline void setup_log_buf(int early)
 {
 }
+
+static inline void dump_stack_set_arch_desc(const char *fmt, ...)
+{
+}
+
+static inline void dump_stack_print_info(const char *log_lvl)
+{
+}
+
+static inline void show_regs_print_info(const char *log_lvl)
+{
+}
 #endif
 
 extern void dump_stack(void) __cold;
diff --git a/include/linux/relay.h b/include/linux/relay.h
index 91cacc34c15..d7c8359693c 100644
--- a/include/linux/relay.h
+++ b/include/linux/relay.h
@@ -20,9 +20,6 @@
 #include <linux/poll.h>
 #include <linux/kref.h>
 
-/* Needs a _much_ better name... */
-#define FIX_SIZE(x) ((((x) - 1) & PAGE_MASK) + PAGE_SIZE)
-
 /*
  * Tracks changes to rchan/rchan_buf structs
  */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 54ddcb82cdd..6f950048b6e 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -626,6 +626,7 @@ struct signal_struct {
 #define SIGNAL_STOP_STOPPED	0x00000001 /* job control stop in effect */
 #define SIGNAL_STOP_CONTINUED	0x00000002 /* SIGCONT since WCONTINUED reap */
 #define SIGNAL_GROUP_EXIT	0x00000004 /* group exit in progress */
+#define SIGNAL_GROUP_COREDUMP	0x00000008 /* coredump in progress */
 /*
  * Pending notifications to parent.
  */
@@ -2248,27 +2249,18 @@ static inline void threadgroup_change_end(struct task_struct *tsk)
  *
  * Lock the threadgroup @tsk belongs to.  No new task is allowed to enter
  * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
- * perform exec.  This is useful for cases where the threadgroup needs to
- * stay stable across blockable operations.
+ * change ->group_leader/pid.  This is useful for cases where the threadgroup
+ * needs to stay stable across blockable operations.
  *
  * fork and exit paths explicitly call threadgroup_change_{begin|end}() for
  * synchronization.  While held, no new task will be added to threadgroup
  * and no existing live task will have its PF_EXITING set.
  *
- * During exec, a task goes and puts its thread group through unusual
- * changes.  After de-threading, exclusive access is assumed to resources
- * which are usually shared by tasks in the same group - e.g. sighand may
- * be replaced with a new one.  Also, the exec'ing task takes over group
- * leader role including its pid.  Exclude these changes while locked by
- * grabbing cred_guard_mutex which is used to synchronize exec path.
+ * de_thread() does threadgroup_change_{begin|end}() when a non-leader
+ * sub-thread becomes a new leader.
  */
 static inline void threadgroup_lock(struct task_struct *tsk)
 {
-	/*
-	 * exec uses exit for de-threading nesting group_rwsem inside
-	 * cred_guard_mutex. Grab cred_guard_mutex first.
-	 */
-	mutex_lock(&tsk->signal->cred_guard_mutex);
 	down_write(&tsk->signal->group_rwsem);
 }
 
@@ -2281,7 +2273,6 @@ static inline void threadgroup_lock(struct task_struct *tsk)
 static inline void threadgroup_unlock(struct task_struct *tsk)
 {
 	up_write(&tsk->signal->group_rwsem);
-	mutex_unlock(&tsk->signal->cred_guard_mutex);
 }
 #else
 static inline void threadgroup_change_begin(struct task_struct *tsk) {}
diff --git a/include/linux/smp.h b/include/linux/smp.h
index 3e07a7df647..e6564c1dc55 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -20,7 +20,6 @@ struct call_single_data {
 	smp_call_func_t func;
 	void *info;
 	u16 flags;
-	u16 priv;
 };
 
 /* total number of cpus in this system (may exceed NR_CPUS) */
diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h
index a3eb2f65b65..3eeee9672a4 100644
--- a/include/linux/string_helpers.h
+++ b/include/linux/string_helpers.h
@@ -13,4 +13,62 @@ enum string_size_units {
 int string_get_size(u64 size, enum string_size_units units,
 		    char *buf, int len);
 
+#define UNESCAPE_SPACE		0x01
+#define UNESCAPE_OCTAL		0x02
+#define UNESCAPE_HEX		0x04
+#define UNESCAPE_SPECIAL	0x08
+#define UNESCAPE_ANY		\
+	(UNESCAPE_SPACE | UNESCAPE_OCTAL | UNESCAPE_HEX | UNESCAPE_SPECIAL)
+
+/**
+ * string_unescape - unquote characters in the given string
+ * @src:	source buffer (escaped)
+ * @dst:	destination buffer (unescaped)
+ * @size:	size of the destination buffer (0 to unlimit)
+ * @flags:	combination of the flags (bitwise OR):
+ *	%UNESCAPE_SPACE:
+ *		'\f' - form feed
+ *		'\n' - new line
+ *		'\r' - carriage return
+ *		'\t' - horizontal tab
+ *		'\v' - vertical tab
+ *	%UNESCAPE_OCTAL:
+ *		'\NNN' - byte with octal value NNN (1 to 3 digits)
+ *	%UNESCAPE_HEX:
+ *		'\xHH' - byte with hexadecimal value HH (1 to 2 digits)
+ *	%UNESCAPE_SPECIAL:
+ *		'\"' - double quote
+ *		'\\' - backslash
+ *		'\a' - alert (BEL)
+ *		'\e' - escape
+ *	%UNESCAPE_ANY:
+ *		all previous together
+ *
+ * Returns amount of characters processed to the destination buffer excluding
+ * trailing '\0'.
+ *
+ * Because the size of the output will be the same as or less than the size of
+ * the input, the transformation may be performed in place.
+ *
+ * Caller must provide valid source and destination pointers. Be aware that
+ * destination buffer will always be NULL-terminated. Source string must be
+ * NULL-terminated as well.
+ */
+int string_unescape(char *src, char *dst, size_t size, unsigned int flags);
+
+static inline int string_unescape_inplace(char *buf, unsigned int flags)
+{
+	return string_unescape(buf, buf, 0, flags);
+}
+
+static inline int string_unescape_any(char *src, char *dst, size_t size)
+{
+	return string_unescape(src, dst, size, UNESCAPE_ANY);
+}
+
+static inline int string_unescape_any_inplace(char *buf)
+{
+	return string_unescape_any(buf, buf, 0);
+}
+
 #endif
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 71797563937..623488fdc1f 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -92,6 +92,9 @@ enum {
 	/* bit mask for work_busy() return values */
 	WORK_BUSY_PENDING	= 1 << 0,
 	WORK_BUSY_RUNNING	= 1 << 1,
+
+	/* maximum string length for set_worker_desc() */
+	WORKER_DESC_LEN		= 24,
 };
 
 struct work_struct {
@@ -447,6 +450,8 @@ extern void workqueue_set_max_active(struct workqueue_struct *wq,
 extern bool current_is_workqueue_rescuer(void);
 extern bool workqueue_congested(int cpu, struct workqueue_struct *wq);
 extern unsigned int work_busy(struct work_struct *work);
+extern __printf(1, 2) void set_worker_desc(const char *fmt, ...);
+extern void print_worker_info(const char *log_lvl, struct task_struct *task);
 
 /**
  * queue_work - queue work on a workqueue