Merge branch 'akpm' (incoming from Andrew)

Merge misc updates from Andrew Morton:

 - a few hotfixes

 - dynamic-debug updates

 - ipc updates

 - various other sweepings off the factory floor

* akpm: (31 commits)
  firmware/google: drop 'select EFI' to avoid recursive dependency
  compat: fix sys_fanotify_mark
  checkpatch.pl: check for function declarations without arguments
  mm/migrate.c: fix setting of cpupid on page migration twice against normal page
  softirq: use const char * const for softirq_to_name, whitespace neatening
  softirq: convert printks to pr_<level>
  softirq: use ffs() in __do_softirq()
  kernel/kexec.c: use vscnprintf() instead of vsnprintf() in vmcoreinfo_append_str()
  splice: fix unexpected size truncation
  ipc: fix compat msgrcv with negative msgtyp
  ipc,msg: document barriers
  ipc: delete seq_max field in struct ipc_ids
  ipc: simplify sysvipc_proc_open() return
  ipc: remove useless return statement
  ipc: remove braces for single statements
  ipc: standardize code comments
  ipc: whitespace cleanup
  ipc: change kern_ipc_perm.deleted type to bool
  ipc: introduce ipc_valid_object() helper to sort out IPC_RMID races
  ipc/sem.c: avoid overflow of semop undo (semadj) value
  ...

arch/arm/kernel/setup.c

@@ -731,7 +731,7 @@ static void __init request_standard_resources(const struct machine_desc *mdesc)
 	kernel_data.end     = virt_to_phys(_end - 1);
 
 	for_each_memblock(memory, region) {
-		res = memblock_virt_alloc(sizeof(*res), 0);
+		res = memblock_virt_alloc_low(sizeof(*res), 0);
 		res->name  = "System RAM";
 		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
 		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;

arch/unicore32/kernel/early_printk.c

@@ -35,17 +35,11 @@ static struct console early_ocd_console = {
 
 static int __init setup_early_printk(char *buf)
 {
-	int keep_early;
-
 	if (!buf || early_console)
 		return 0;
 
-	if (strstr(buf, "keep"))
-		keep_early = 1;
-
 	early_console = &early_ocd_console;
-
-	if (keep_early)
+	if (strstr(buf, "keep"))
 		early_console->flags &= ~CON_BOOT;
 	else
 		early_console->flags |= CON_BOOT;

arch/x86/include/asm/page_types.h

@@ -51,9 +51,9 @@ extern int devmem_is_allowed(unsigned long pagenr);
 extern unsigned long max_low_pfn_mapped;
 extern unsigned long max_pfn_mapped;
 
-static inline phys_addr_t get_max_low_mapped(void)
+static inline phys_addr_t get_max_mapped(void)
 {
-	return (phys_addr_t)max_low_pfn_mapped << PAGE_SHIFT;
+	return (phys_addr_t)max_pfn_mapped << PAGE_SHIFT;
 }
 
 bool pfn_range_is_mapped(unsigned long start_pfn, unsigned long end_pfn);

arch/x86/kernel/setup.c

@@ -1119,7 +1119,7 @@ void __init setup_arch(char **cmdline_p)
 
 	setup_real_mode();
 
-	memblock_set_current_limit(get_max_low_mapped());
+	memblock_set_current_limit(get_max_mapped());
 	dma_contiguous_reserve(0);
 
 	/*

drivers/firmware/google/Kconfig

@@ -12,8 +12,7 @@ menu "Google Firmware Drivers"
 
 config GOOGLE_SMI
 	tristate "SMI interface for Google platforms"
-	depends on ACPI && DMI
-	select EFI
+	depends on ACPI && DMI && EFI
 	select EFI_VARS
 	help
 	  Say Y here if you want to enable SMI callbacks for Google

fs/notify/fanotify/fanotify_user.c

@@ -886,9 +886,9 @@ COMPAT_SYSCALL_DEFINE6(fanotify_mark,
 {
 	return sys_fanotify_mark(fanotify_fd, flags,
 #ifdef __BIG_ENDIAN
-				((__u64)mask1 << 32) | mask0,
-#else
 				((__u64)mask0 << 32) | mask1,
+#else
+				((__u64)mask1 << 32) | mask0,
 #endif
 				 dfd, pathname);
 }

fs/ocfs2/namei.c

@@ -948,7 +948,7 @@ static int ocfs2_unlink(struct inode *dir,
 	ocfs2_free_dir_lookup_result(&orphan_insert);
 	ocfs2_free_dir_lookup_result(&lookup);
 
-	if (status && (status != -ENOTEMPTY))
+	if (status && (status != -ENOTEMPTY) && (status != -ENOENT))
 		mlog_errno(status);
 
 	return status;

include/linux/bootmem.h

@@ -175,6 +175,27 @@ static inline void * __init memblock_virt_alloc_nopanic(
 						    NUMA_NO_NODE);
 }
 
+#ifndef ARCH_LOW_ADDRESS_LIMIT
+#define ARCH_LOW_ADDRESS_LIMIT  0xffffffffUL
+#endif
+
+static inline void * __init memblock_virt_alloc_low(
+					phys_addr_t size, phys_addr_t align)
+{
+	return memblock_virt_alloc_try_nid(size, align,
+						   BOOTMEM_LOW_LIMIT,
+						   ARCH_LOW_ADDRESS_LIMIT,
+						   NUMA_NO_NODE);
+}
+static inline void * __init memblock_virt_alloc_low_nopanic(
+					phys_addr_t size, phys_addr_t align)
+{
+	return memblock_virt_alloc_try_nid_nopanic(size, align,
+						   BOOTMEM_LOW_LIMIT,
+						   ARCH_LOW_ADDRESS_LIMIT,
+						   NUMA_NO_NODE);
+}
+
 static inline void * __init memblock_virt_alloc_from_nopanic(
 		phys_addr_t size, phys_addr_t align, phys_addr_t min_addr)
 {
@@ -238,6 +259,22 @@ static inline void * __init memblock_virt_alloc_nopanic(
 	return __alloc_bootmem_nopanic(size, align, BOOTMEM_LOW_LIMIT);
 }
 
+static inline void * __init memblock_virt_alloc_low(
+					phys_addr_t size, phys_addr_t align)
+{
+	if (!align)
+		align = SMP_CACHE_BYTES;
+	return __alloc_bootmem_low(size, align, BOOTMEM_LOW_LIMIT);
+}
+
+static inline void * __init memblock_virt_alloc_low_nopanic(
+					phys_addr_t size, phys_addr_t align)
+{
+	if (!align)
+		align = SMP_CACHE_BYTES;
+	return __alloc_bootmem_low_nopanic(size, align, BOOTMEM_LOW_LIMIT);
+}
+
 static inline void * __init memblock_virt_alloc_from_nopanic(
 		phys_addr_t size, phys_addr_t align, phys_addr_t min_addr)
 {

include/linux/interrupt.h

@@ -360,7 +360,7 @@ enum
 /* map softirq index to softirq name. update 'softirq_to_name' in
  * kernel/softirq.c when adding a new softirq.
  */
-extern char *softirq_to_name[NR_SOFTIRQS];
+extern const char * const softirq_to_name[NR_SOFTIRQS];
 
 /* softirq mask and active fields moved to irq_cpustat_t in
  * asm/hardirq.h to get better cache usage.  KAO

include/linux/ipc.h

@@ -11,7 +11,7 @@
 struct kern_ipc_perm
 {
 	spinlock_t	lock;
-	int		deleted;
+	bool		deleted;
 	int		id;
 	key_t		key;
 	kuid_t		uid;

include/linux/ipc_namespace.h

@@ -21,7 +21,6 @@ struct user_namespace;
 struct ipc_ids {
 	int in_use;
 	unsigned short seq;
-	unsigned short seq_max;
 	struct rw_semaphore rwsem;
 	struct idr ipcs_idr;
 	int next_id;

include/linux/msg.h

@@ -9,7 +9,7 @@ struct msg_msg {
 	struct list_head m_list;
 	long m_type;
 	size_t m_ts;		/* message text size */
-	struct msg_msgseg* next;
+	struct msg_msgseg *next;
 	void *security;
 	/* the actual message follows immediately */
 };

include/linux/shm.h

@@ -9,7 +9,7 @@
 struct shmid_kernel /* private to the kernel */
 {	
 	struct kern_ipc_perm	shm_perm;
-	struct file *		shm_file;
+	struct file		*shm_file;
 	unsigned long		shm_nattch;
 	unsigned long		shm_segsz;
 	time_t			shm_atim;

include/linux/splice.h

@@ -24,7 +24,8 @@
  * Passed to the actors
  */
 struct splice_desc {
-	unsigned int len, total_len;	/* current and remaining length */
+	size_t total_len;		/* remaining length */
+	unsigned int len;		/* current length */
 	unsigned int flags;		/* splice flags */
 	/*
 	 * actor() private data

init/main.c

@@ -92,8 +92,6 @@ static int kernel_init(void *);
 
 extern void init_IRQ(void);
 extern void fork_init(unsigned long);
-extern void mca_init(void);
-extern void sbus_init(void);
 extern void radix_tree_init(void);
 #ifndef CONFIG_DEBUG_RODATA
 static inline void mark_rodata_ro(void) { }

ipc/compat.c

@@ -197,7 +197,7 @@ static inline int __put_compat_ipc_perm(struct ipc64_perm *p,
 static inline int get_compat_semid64_ds(struct semid64_ds *s64,
 					struct compat_semid64_ds __user *up64)
 {
-	if (!access_ok (VERIFY_READ, up64, sizeof(*up64)))
+	if (!access_ok(VERIFY_READ, up64, sizeof(*up64)))
 		return -EFAULT;
 	return __get_compat_ipc64_perm(&s64->sem_perm, &up64->sem_perm);
 }
@@ -205,7 +205,7 @@ static inline int get_compat_semid64_ds(struct semid64_ds *s64,
 static inline int get_compat_semid_ds(struct semid64_ds *s,
 				      struct compat_semid_ds __user *up)
 {
-	if (!access_ok (VERIFY_READ, up, sizeof(*up)))
+	if (!access_ok(VERIFY_READ, up, sizeof(*up)))
 		return -EFAULT;
 	return __get_compat_ipc_perm(&s->sem_perm, &up->sem_perm);
 }
@@ -215,7 +215,7 @@ static inline int put_compat_semid64_ds(struct semid64_ds *s64,
 {
 	int err;
 
-	if (!access_ok (VERIFY_WRITE, up64, sizeof(*up64)))
+	if (!access_ok(VERIFY_WRITE, up64, sizeof(*up64)))
 		return -EFAULT;
 	err  = __put_compat_ipc64_perm(&s64->sem_perm, &up64->sem_perm);
 	err |= __put_user(s64->sem_otime, &up64->sem_otime);
@@ -229,7 +229,7 @@ static inline int put_compat_semid_ds(struct semid64_ds *s,
 {
 	int err;
 
-	if (!access_ok (VERIFY_WRITE, up, sizeof(*up)))
+	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)))
 		return -EFAULT;
 	err  = __put_compat_ipc_perm(&s->sem_perm, &up->sem_perm);
 	err |= __put_user(s->sem_otime, &up->sem_otime);
@@ -288,11 +288,11 @@ static long do_compat_semctl(int first, int second, int third, u32 pad)
 		break;
 
 	case IPC_SET:
-		if (version == IPC_64) {
+		if (version == IPC_64)
 			err = get_compat_semid64_ds(&s64, compat_ptr(pad));
-		} else {
+		else
 			err = get_compat_semid_ds(&s64, compat_ptr(pad));
-		}
+
 		up64 = compat_alloc_user_space(sizeof(s64));
 		if (copy_to_user(up64, &s64, sizeof(s64)))
 			err = -EFAULT;
@@ -376,12 +376,12 @@ COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
 			struct compat_ipc_kludge ipck;
 			if (!uptr)
 				return -EINVAL;
-			if (copy_from_user (&ipck, uptr, sizeof(ipck)))
+			if (copy_from_user(&ipck, uptr, sizeof(ipck)))
 				return -EFAULT;
 			uptr = compat_ptr(ipck.msgp);
 			fifth = ipck.msgtyp;
 		}
-		return do_msgrcv(first, uptr, second, fifth, third,
+		return do_msgrcv(first, uptr, second, (s32)fifth, third,
 				 compat_do_msg_fill);
 	}
 	case MSGGET:
@@ -515,11 +515,11 @@ long compat_sys_msgctl(int first, int second, void __user *uptr)
 		break;
 
 	case IPC_SET:
-		if (version == IPC_64) {
+		if (version == IPC_64)
 			err = get_compat_msqid64(&m64, uptr);
-		} else {
+		else
 			err = get_compat_msqid(&m64, uptr);
-		}
+
 		if (err)
 			break;
 		p = compat_alloc_user_space(sizeof(m64));
@@ -702,11 +702,11 @@ long compat_sys_shmctl(int first, int second, void __user *uptr)
 
 
 	case IPC_SET:
-		if (version == IPC_64) {
+		if (version == IPC_64)
 			err = get_compat_shmid64_ds(&s64, uptr);
-		} else {
+		else
 			err = get_compat_shmid_ds(&s64, uptr);
-		}
+
 		if (err)
 			break;
 		p = compat_alloc_user_space(sizeof(s64));

ipc/compat_mq.c

@@ -64,7 +64,7 @@ asmlinkage long compat_sys_mq_open(const char __user *u_name,
 	return sys_mq_open(u_name, oflag, mode, p);
 }
 
-static int compat_prepare_timeout(struct timespec __user * *p,
+static int compat_prepare_timeout(struct timespec __user **p,
 				  const struct compat_timespec __user *u)
 {
 	struct timespec ts;

ipc/ipc_sysctl.c

@@ -164,21 +164,21 @@ static struct ctl_table ipc_kern_table[] = {
 	{
 		.procname	= "shmmax",
 		.data		= &init_ipc_ns.shm_ctlmax,
-		.maxlen		= sizeof (init_ipc_ns.shm_ctlmax),
+		.maxlen		= sizeof(init_ipc_ns.shm_ctlmax),
 		.mode		= 0644,
 		.proc_handler	= proc_ipc_doulongvec_minmax,
 	},
 	{
 		.procname	= "shmall",
 		.data		= &init_ipc_ns.shm_ctlall,
-		.maxlen		= sizeof (init_ipc_ns.shm_ctlall),
+		.maxlen		= sizeof(init_ipc_ns.shm_ctlall),
 		.mode		= 0644,
 		.proc_handler	= proc_ipc_doulongvec_minmax,
 	},
 	{
 		.procname	= "shmmni",
 		.data		= &init_ipc_ns.shm_ctlmni,
-		.maxlen		= sizeof (init_ipc_ns.shm_ctlmni),
+		.maxlen		= sizeof(init_ipc_ns.shm_ctlmni),
 		.mode		= 0644,
 		.proc_handler	= proc_ipc_dointvec,
 	},
@@ -194,7 +194,7 @@ static struct ctl_table ipc_kern_table[] = {
 	{
 		.procname	= "msgmax",
 		.data		= &init_ipc_ns.msg_ctlmax,
-		.maxlen		= sizeof (init_ipc_ns.msg_ctlmax),
+		.maxlen		= sizeof(init_ipc_ns.msg_ctlmax),
 		.mode		= 0644,
 		.proc_handler	= proc_ipc_dointvec_minmax,
 		.extra1		= &zero,
@@ -203,7 +203,7 @@ static struct ctl_table ipc_kern_table[] = {
 	{
 		.procname	= "msgmni",
 		.data		= &init_ipc_ns.msg_ctlmni,
-		.maxlen		= sizeof (init_ipc_ns.msg_ctlmni),
+		.maxlen		= sizeof(init_ipc_ns.msg_ctlmni),
 		.mode		= 0644,
 		.proc_handler	= proc_ipc_callback_dointvec_minmax,
 		.extra1		= &zero,
@@ -212,7 +212,7 @@ static struct ctl_table ipc_kern_table[] = {
 	{
 		.procname	=  "msgmnb",
 		.data		= &init_ipc_ns.msg_ctlmnb,
-		.maxlen		= sizeof (init_ipc_ns.msg_ctlmnb),
+		.maxlen		= sizeof(init_ipc_ns.msg_ctlmnb),
 		.mode		= 0644,
 		.proc_handler	= proc_ipc_dointvec_minmax,
 		.extra1		= &zero,
@@ -221,7 +221,7 @@ static struct ctl_table ipc_kern_table[] = {
 	{
 		.procname	= "sem",
 		.data		= &init_ipc_ns.sem_ctls,
-		.maxlen		= 4*sizeof (int),
+		.maxlen		= 4*sizeof(int),
 		.mode		= 0644,
 		.proc_handler	= proc_ipc_dointvec,
 	},

ipc/mqueue.c

@@ -73,7 +73,7 @@ struct mqueue_inode_info {
 	struct mq_attr attr;
 
 	struct sigevent notify;
-	struct pid* notify_owner;
+	struct pid *notify_owner;
 	struct user_namespace *notify_user_ns;
 	struct user_struct *user;	/* user who created, for accounting */
 	struct sock *notify_sock;
@@ -92,7 +92,7 @@ static void remove_notification(struct mqueue_inode_info *info);
 
 static struct kmem_cache *mqueue_inode_cachep;
 
-static struct ctl_table_header * mq_sysctl_table;
+static struct ctl_table_header *mq_sysctl_table;
 
 static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode)
 {
@@ -622,7 +622,7 @@ static struct ext_wait_queue *wq_get_first_waiter(
 
 static inline void set_cookie(struct sk_buff *skb, char code)
 {
-	((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code;
+	((char *)skb->data)[NOTIFY_COOKIE_LEN-1] = code;
 }
 
 /*
@@ -1303,11 +1303,11 @@ SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
 out_fput:
 	fdput(f);
 out:
-	if (sock) {
+	if (sock)
 		netlink_detachskb(sock, nc);
-	} else if (nc) {
+	else if (nc)
 		dev_kfree_skb(nc);
-	}
+
 	return ret;
 }
 

ipc/msg.c

@@ -253,8 +253,14 @@ static void expunge_all(struct msg_queue *msq, int res)
 	struct msg_receiver *msr, *t;
 
 	list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
-		msr->r_msg = NULL;
+		msr->r_msg = NULL; /* initialize expunge ordering */
 		wake_up_process(msr->r_tsk);
+		/*
+		 * Ensure that the wakeup is visible before setting r_msg as
+		 * the receiving end depends on it: either spinning on a nil,
+		 * or dealing with -EAGAIN cases. See lockless receive part 1
+		 * and 2 in do_msgrcv().
+		 */
 		smp_mb();
 		msr->r_msg = ERR_PTR(res);
 	}
@@ -318,7 +324,7 @@ SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg)
 static inline unsigned long
 copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version)
 {
-	switch(version) {
+	switch (version) {
 	case IPC_64:
 		return copy_to_user(buf, in, sizeof(*in));
 	case IPC_OLD:
@@ -363,7 +369,7 @@ copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version)
 static inline unsigned long
 copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
 {
-	switch(version) {
+	switch (version) {
 	case IPC_64:
 		if (copy_from_user(out, buf, sizeof(*out)))
 			return -EFAULT;
@@ -606,13 +612,13 @@ SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
 
 static int testmsg(struct msg_msg *msg, long type, int mode)
 {
-	switch(mode)
+	switch (mode)
 	{
 		case SEARCH_ANY:
 		case SEARCH_NUMBER:
 			return 1;
 		case SEARCH_LESSEQUAL:
-			if (msg->m_type <=type)
+			if (msg->m_type <= type)
 				return 1;
 			break;
 		case SEARCH_EQUAL:
@@ -638,15 +644,22 @@ static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg)
 
 			list_del(&msr->r_list);
 			if (msr->r_maxsize < msg->m_ts) {
+				/* initialize pipelined send ordering */
 				msr->r_msg = NULL;
 				wake_up_process(msr->r_tsk);
-				smp_mb();
+				smp_mb(); /* see barrier comment below */
 				msr->r_msg = ERR_PTR(-E2BIG);
 			} else {
 				msr->r_msg = NULL;
 				msq->q_lrpid = task_pid_vnr(msr->r_tsk);
 				msq->q_rtime = get_seconds();
 				wake_up_process(msr->r_tsk);
+				/*
+				 * Ensure that the wakeup is visible before
+				 * setting r_msg, as the receiving end depends
+				 * on it. See lockless receive part 1 and 2 in
+				 * do_msgrcv().
+				 */
 				smp_mb();
 				msr->r_msg = msg;
 
@@ -654,6 +667,7 @@ static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg)
 			}
 		}
 	}
+
 	return 0;
 }
 
@@ -696,7 +710,7 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext,
 			goto out_unlock0;
 
 		/* raced with RMID? */
-		if (msq->q_perm.deleted) {
+		if (!ipc_valid_object(&msq->q_perm)) {
 			err = -EIDRM;
 			goto out_unlock0;
 		}
@@ -716,6 +730,7 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext,
 			goto out_unlock0;
 		}
 
+		/* enqueue the sender and prepare to block */
 		ss_add(msq, &s);
 
 		if (!ipc_rcu_getref(msq)) {
@@ -731,7 +746,8 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext,
 		ipc_lock_object(&msq->q_perm);
 
 		ipc_rcu_putref(msq, ipc_rcu_free);
-		if (msq->q_perm.deleted) {
+		/* raced with RMID? */
+		if (!ipc_valid_object(&msq->q_perm)) {
 			err = -EIDRM;
 			goto out_unlock0;
 		}
@@ -909,7 +925,7 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgfl
 		ipc_lock_object(&msq->q_perm);
 
 		/* raced with RMID? */
-		if (msq->q_perm.deleted) {
+		if (!ipc_valid_object(&msq->q_perm)) {
 			msg = ERR_PTR(-EIDRM);
 			goto out_unlock0;
 		}
@@ -983,7 +999,7 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgfl
 		 * wake_up_process(). There is a race with exit(), see
 		 * ipc/mqueue.c for the details.
 		 */
-		msg = (struct msg_msg*)msr_d.r_msg;
+		msg = (struct msg_msg *)msr_d.r_msg;
 		while (msg == NULL) {
 			cpu_relax();
 			msg = (struct msg_msg *)msr_d.r_msg;
@@ -1004,7 +1020,7 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgfl
 		/* Lockless receive, part 4:
 		 * Repeat test after acquiring the spinlock.
 		 */
-		msg = (struct msg_msg*)msr_d.r_msg;
+		msg = (struct msg_msg *)msr_d.r_msg;
 		if (msg != ERR_PTR(-EAGAIN))
 			goto out_unlock0;
 

ipc/sem.c

@@ -188,7 +188,7 @@ void sem_exit_ns(struct ipc_namespace *ns)
 }
 #endif
 
-void __init sem_init (void)
+void __init sem_init(void)
 {
 	sem_init_ns(&init_ipc_ns);
 	ipc_init_proc_interface("sysvipc/sem",
@@ -225,7 +225,7 @@ static void unmerge_queues(struct sem_array *sma)
 }
 
 /**
- * merge_queues - Merge single semop queues into global queue
+ * merge_queues - merge single semop queues into global queue
  * @sma: semaphore array
  *
  * This function merges all per-semaphore queues into the global queue.
@@ -394,7 +394,7 @@ static inline struct sem_array *sem_obtain_lock(struct ipc_namespace *ns,
 	/* ipc_rmid() may have already freed the ID while sem_lock
 	 * was spinning: verify that the structure is still valid
 	 */
-	if (!ipcp->deleted)
+	if (ipc_valid_object(ipcp))
 		return container_of(ipcp, struct sem_array, sem_perm);
 
 	sem_unlock(sma, *locknum);
@@ -474,7 +474,6 @@ static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
  *
  * Called with sem_ids.rwsem held (as a writer)
  */
-
 static int newary(struct ipc_namespace *ns, struct ipc_params *params)
 {
 	int id;
@@ -491,12 +490,12 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params)
 	if (ns->used_sems + nsems > ns->sc_semmns)
 		return -ENOSPC;
 
-	size = sizeof (*sma) + nsems * sizeof (struct sem);
+	size = sizeof(*sma) + nsems * sizeof(struct sem);
 	sma = ipc_rcu_alloc(size);
-	if (!sma) {
+	if (!sma)
 		return -ENOMEM;
-	}
-	memset (sma, 0, size);
+
+	memset(sma, 0, size);
 
 	sma->sem_perm.mode = (semflg & S_IRWXUGO);
 	sma->sem_perm.key = key;
@@ -584,10 +583,11 @@ SYSCALL_DEFINE3(semget, key_t, key, int, nsems, int, semflg)
 	return ipcget(ns, &sem_ids(ns), &sem_ops, &sem_params);
 }
 
-/** perform_atomic_semop - Perform (if possible) a semaphore operation
+/**
+ * perform_atomic_semop - Perform (if possible) a semaphore operation
  * @sma: semaphore array
  * @sops: array with operations that should be checked
- * @nsems: number of sops
+ * @nsops: number of operations
  * @un: undo array
  * @pid: pid that did the change
  *
@@ -595,13 +595,12 @@ SYSCALL_DEFINE3(semget, key_t, key, int, nsems, int, semflg)
  * Returns 1 if the operation is impossible, the caller must sleep.
  * Negative values are error codes.
  */
-
 static int perform_atomic_semop(struct sem_array *sma, struct sembuf *sops,
 			     int nsops, struct sem_undo *un, int pid)
 {
 	int result, sem_op;
 	struct sembuf *sop;
-	struct sem * curr;
+	struct sem *curr;
 
 	for (sop = sops; sop < sops + nsops; sop++) {
 		curr = sma->sem_base + sop->sem_num;
@@ -616,22 +615,21 @@ static int perform_atomic_semop(struct sem_array *sma, struct sembuf *sops,
 			goto would_block;
 		if (result > SEMVMX)
 			goto out_of_range;
+
 		if (sop->sem_flg & SEM_UNDO) {
 			int undo = un->semadj[sop->sem_num] - sem_op;
-			/*
-	 		 *	Exceeding the undo range is an error.
-			 */
+			/* Exceeding the undo range is an error. */
 			if (undo < (-SEMAEM - 1) || undo > SEMAEM)
 				goto out_of_range;
+			un->semadj[sop->sem_num] = undo;
 		}
+
 		curr->semval = result;
 	}
 
 	sop--;
 	while (sop >= sops) {
 		sma->sem_base[sop->sem_num].sempid = pid;
-		if (sop->sem_flg & SEM_UNDO)
-			un->semadj[sop->sem_num] -= sop->sem_op;
 		sop--;
 	}
 
@@ -650,7 +648,10 @@ static int perform_atomic_semop(struct sem_array *sma, struct sembuf *sops,
 undo:
 	sop--;
 	while (sop >= sops) {
-		sma->sem_base[sop->sem_num].semval -= sop->sem_op;
+		sem_op = sop->sem_op;
+		sma->sem_base[sop->sem_num].semval -= sem_op;
+		if (sop->sem_flg & SEM_UNDO)
+			un->semadj[sop->sem_num] += sem_op;
 		sop--;
 	}
 
@@ -680,7 +681,7 @@ static void wake_up_sem_queue_prepare(struct list_head *pt,
 }
 
 /**
- * wake_up_sem_queue_do(pt) - do the actual wake-up
+ * wake_up_sem_queue_do - do the actual wake-up
  * @pt: list of tasks to be woken up
  *
  * Do the actual wake-up.
@@ -746,7 +747,7 @@ static int check_restart(struct sem_array *sma, struct sem_queue *q)
 }
 
 /**
- * wake_const_ops(sma, semnum, pt) - Wake up non-alter tasks
+ * wake_const_ops - wake up non-alter tasks
  * @sma: semaphore array.
  * @semnum: semaphore that was modified.
  * @pt: list head for the tasks that must be woken up.
@@ -796,15 +797,14 @@ static int wake_const_ops(struct sem_array *sma, int semnum,
 }
 
 /**
- * do_smart_wakeup_zero(sma, sops, nsops, pt) - wakeup all wait for zero tasks
+ * do_smart_wakeup_zero - wakeup all wait for zero tasks
  * @sma: semaphore array
  * @sops: operations that were performed
  * @nsops: number of operations
  * @pt: list head of the tasks that must be woken up.
  *
- * do_smart_wakeup_zero() checks all required queue for wait-for-zero
- * operations, based on the actual changes that were performed on the
- * semaphore array.
+ * Checks all required queue for wait-for-zero operations, based
+ * on the actual changes that were performed on the semaphore array.
  * The function returns 1 if at least one operation was completed successfully.
  */
 static int do_smart_wakeup_zero(struct sem_array *sma, struct sembuf *sops,
@@ -848,7 +848,7 @@ static int do_smart_wakeup_zero(struct sem_array *sma, struct sembuf *sops,
 
 
 /**
- * update_queue(sma, semnum): Look for tasks that can be completed.
+ * update_queue - look for tasks that can be completed.
  * @sma: semaphore array.
  * @semnum: semaphore that was modified.
  * @pt: list head for the tasks that must be woken up.
@@ -918,7 +918,7 @@ static int update_queue(struct sem_array *sma, int semnum, struct list_head *pt)
 }
 
 /**
- * set_semotime(sma, sops) - set sem_otime
+ * set_semotime - set sem_otime
  * @sma: semaphore array
  * @sops: operations that modified the array, may be NULL
  *
@@ -936,7 +936,7 @@ static void set_semotime(struct sem_array *sma, struct sembuf *sops)
 }
 
 /**
- * do_smart_update(sma, sops, nsops, otime, pt) - optimized update_queue
+ * do_smart_update - optimized update_queue
  * @sma: semaphore array
  * @sops: operations that were performed
  * @nsops: number of operations
@@ -998,21 +998,21 @@ static void do_smart_update(struct sem_array *sma, struct sembuf *sops, int nsop
  * The counts we return here are a rough approximation, but still
  * warrant that semncnt+semzcnt>0 if the task is on the pending queue.
  */
-static int count_semncnt (struct sem_array * sma, ushort semnum)
+static int count_semncnt(struct sem_array *sma, ushort semnum)
 {
 	int semncnt;
-	struct sem_queue * q;
+	struct sem_queue *q;
 
 	semncnt = 0;
 	list_for_each_entry(q, &sma->sem_base[semnum].pending_alter, list) {
-		struct sembuf * sops = q->sops;
+		struct sembuf *sops = q->sops;
 		BUG_ON(sops->sem_num != semnum);
 		if ((sops->sem_op < 0) && !(sops->sem_flg & IPC_NOWAIT))
 			semncnt++;
 	}
 
 	list_for_each_entry(q, &sma->pending_alter, list) {
-		struct sembuf * sops = q->sops;
+		struct sembuf *sops = q->sops;
 		int nsops = q->nsops;
 		int i;
 		for (i = 0; i < nsops; i++)
@@ -1024,21 +1024,21 @@ static int count_semncnt (struct sem_array * sma, ushort semnum)
 	return semncnt;
 }
 
-static int count_semzcnt (struct sem_array * sma, ushort semnum)
+static int count_semzcnt(struct sem_array *sma, ushort semnum)
 {
 	int semzcnt;
-	struct sem_queue * q;
+	struct sem_queue *q;
 
 	semzcnt = 0;
 	list_for_each_entry(q, &sma->sem_base[semnum].pending_const, list) {
-		struct sembuf * sops = q->sops;
+		struct sembuf *sops = q->sops;
 		BUG_ON(sops->sem_num != semnum);
 		if ((sops->sem_op == 0) && !(sops->sem_flg & IPC_NOWAIT))
 			semzcnt++;
 	}
 
 	list_for_each_entry(q, &sma->pending_const, list) {
-		struct sembuf * sops = q->sops;
+		struct sembuf *sops = q->sops;
 		int nsops = q->nsops;
 		int i;
 		for (i = 0; i < nsops; i++)
@@ -1108,7 +1108,7 @@ static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
 
 static unsigned long copy_semid_to_user(void __user *buf, struct semid64_ds *in, int version)
 {
-	switch(version) {
+	switch (version) {
 	case IPC_64:
 		return copy_to_user(buf, in, sizeof(*in));
 	case IPC_OLD:
@@ -1151,7 +1151,7 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid,
 	int err;
 	struct sem_array *sma;
 
-	switch(cmd) {
+	switch (cmd) {
 	case IPC_INFO:
 	case SEM_INFO:
 	{
@@ -1162,7 +1162,7 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid,
 		if (err)
 			return err;
 		
-		memset(&seminfo,0,sizeof(seminfo));
+		memset(&seminfo, 0, sizeof(seminfo));
 		seminfo.semmni = ns->sc_semmni;
 		seminfo.semmns = ns->sc_semmns;
 		seminfo.semmsl = ns->sc_semmsl;
@@ -1183,7 +1183,7 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid,
 		up_read(&sem_ids(ns).rwsem);
 		if (copy_to_user(p, &seminfo, sizeof(struct seminfo))) 
 			return -EFAULT;
-		return (max_id < 0) ? 0: max_id;
+		return (max_id < 0) ? 0 : max_id;
 	}
 	case IPC_STAT:
 	case SEM_STAT:
@@ -1239,7 +1239,7 @@ static int semctl_setval(struct ipc_namespace *ns, int semid, int semnum,
 {
 	struct sem_undo *un;
 	struct sem_array *sma;
-	struct sem* curr;
+	struct sem *curr;
 	int err;
 	struct list_head tasks;
 	int val;
@@ -1282,7 +1282,7 @@ static int semctl_setval(struct ipc_namespace *ns, int semid, int semnum,
 
 	sem_lock(sma, NULL, -1);
 
-	if (sma->sem_perm.deleted) {
+	if (!ipc_valid_object(&sma->sem_perm)) {
 		sem_unlock(sma, -1);
 		rcu_read_unlock();
 		return -EIDRM;
@@ -1309,10 +1309,10 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
 		int cmd, void __user *p)
 {
 	struct sem_array *sma;
-	struct sem* curr;
+	struct sem *curr;
 	int err, nsems;
 	ushort fast_sem_io[SEMMSL_FAST];
-	ushort* sem_io = fast_sem_io;
+	ushort *sem_io = fast_sem_io;
 	struct list_head tasks;
 
 	INIT_LIST_HEAD(&tasks);
@@ -1342,11 +1342,11 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
 		int i;
 
 		sem_lock(sma, NULL, -1);
-		if (sma->sem_perm.deleted) {
+		if (!ipc_valid_object(&sma->sem_perm)) {
 			err = -EIDRM;
 			goto out_unlock;
 		}
-		if(nsems > SEMMSL_FAST) {
+		if (nsems > SEMMSL_FAST) {
 			if (!ipc_rcu_getref(sma)) {
 				err = -EIDRM;
 				goto out_unlock;
@@ -1354,14 +1354,14 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
 			sem_unlock(sma, -1);
 			rcu_read_unlock();
 			sem_io = ipc_alloc(sizeof(ushort)*nsems);
-			if(sem_io == NULL) {
+			if (sem_io == NULL) {
 				ipc_rcu_putref(sma, ipc_rcu_free);
 				return -ENOMEM;
 			}
 
 			rcu_read_lock();
 			sem_lock_and_putref(sma);
-			if (sma->sem_perm.deleted) {
+			if (!ipc_valid_object(&sma->sem_perm)) {
 				err = -EIDRM;
 				goto out_unlock;
 			}
@@ -1371,7 +1371,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
 		sem_unlock(sma, -1);
 		rcu_read_unlock();
 		err = 0;
-		if(copy_to_user(array, sem_io, nsems*sizeof(ushort)))
+		if (copy_to_user(array, sem_io, nsems*sizeof(ushort)))
 			err = -EFAULT;
 		goto out_free;
 	}
@@ -1386,15 +1386,15 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
 		}
 		rcu_read_unlock();
 
-		if(nsems > SEMMSL_FAST) {
+		if (nsems > SEMMSL_FAST) {
 			sem_io = ipc_alloc(sizeof(ushort)*nsems);
-			if(sem_io == NULL) {
+			if (sem_io == NULL) {
 				ipc_rcu_putref(sma, ipc_rcu_free);
 				return -ENOMEM;
 			}
 		}
 
-		if (copy_from_user (sem_io, p, nsems*sizeof(ushort))) {
+		if (copy_from_user(sem_io, p, nsems*sizeof(ushort))) {
 			ipc_rcu_putref(sma, ipc_rcu_free);
 			err = -EFAULT;
 			goto out_free;
@@ -1409,7 +1409,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
 		}
 		rcu_read_lock();
 		sem_lock_and_putref(sma);
-		if (sma->sem_perm.deleted) {
+		if (!ipc_valid_object(&sma->sem_perm)) {
 			err = -EIDRM;
 			goto out_unlock;
 		}
@@ -1435,7 +1435,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
 		goto out_rcu_wakeup;
 
 	sem_lock(sma, NULL, -1);
-	if (sma->sem_perm.deleted) {
+	if (!ipc_valid_object(&sma->sem_perm)) {
 		err = -EIDRM;
 		goto out_unlock;
 	}
@@ -1449,10 +1449,10 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
 		err = curr->sempid;
 		goto out_unlock;
 	case GETNCNT:
-		err = count_semncnt(sma,semnum);
+		err = count_semncnt(sma, semnum);
 		goto out_unlock;
 	case GETZCNT:
-		err = count_semzcnt(sma,semnum);
+		err = count_semzcnt(sma, semnum);
 		goto out_unlock;
 	}
 
@@ -1462,7 +1462,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
 	rcu_read_unlock();
 	wake_up_sem_queue_do(&tasks);
 out_free:
-	if(sem_io != fast_sem_io)
+	if (sem_io != fast_sem_io)
 		ipc_free(sem_io, sizeof(ushort)*nsems);
 	return err;
 }
@@ -1470,7 +1470,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
 static inline unsigned long
 copy_semid_from_user(struct semid64_ds *out, void __user *buf, int version)
 {
-	switch(version) {
+	switch (version) {
 	case IPC_64:
 		if (copy_from_user(out, buf, sizeof(*out)))
 			return -EFAULT;
@@ -1479,7 +1479,7 @@ copy_semid_from_user(struct semid64_ds *out, void __user *buf, int version)
 	    {
 		struct semid_ds tbuf_old;
 
-		if(copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
+		if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
 			return -EFAULT;
 
 		out->sem_perm.uid	= tbuf_old.sem_perm.uid;
@@ -1506,7 +1506,7 @@ static int semctl_down(struct ipc_namespace *ns, int semid,
 	struct semid64_ds semid64;
 	struct kern_ipc_perm *ipcp;
 
-	if(cmd == IPC_SET) {
+	if (cmd == IPC_SET) {
 		if (copy_semid_from_user(&semid64, p, version))
 			return -EFAULT;
 	}
@@ -1566,7 +1566,7 @@ SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
 	version = ipc_parse_version(&cmd);
 	ns = current->nsproxy->ipc_ns;
 
-	switch(cmd) {
+	switch (cmd) {
 	case IPC_INFO:
 	case SEM_INFO:
 	case IPC_STAT:
@@ -1645,7 +1645,7 @@ static struct sem_undo *lookup_undo(struct sem_undo_list *ulp, int semid)
 }
 
 /**
- * find_alloc_undo - Lookup (and if not present create) undo array
+ * find_alloc_undo - lookup (and if not present create) undo array
  * @ns: namespace
  * @semid: semaphore array id
  *
@@ -1670,7 +1670,7 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid)
 	spin_lock(&ulp->lock);
 	un = lookup_undo(ulp, semid);
 	spin_unlock(&ulp->lock);
-	if (likely(un!=NULL))
+	if (likely(un != NULL))
 		goto out;
 
 	/* no undo structure around - allocate one. */
@@ -1699,7 +1699,7 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid)
 	/* step 3: Acquire the lock on semaphore array */
 	rcu_read_lock();
 	sem_lock_and_putref(sma);
-	if (sma->sem_perm.deleted) {
+	if (!ipc_valid_object(&sma->sem_perm)) {
 		sem_unlock(sma, -1);
 		rcu_read_unlock();
 		kfree(new);
@@ -1735,7 +1735,7 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid)
 
 
 /**
- * get_queue_result - Retrieve the result code from sem_queue
+ * get_queue_result - retrieve the result code from sem_queue
  * @q: Pointer to queue structure
  *
  * Retrieve the return code from the pending queue. If IN_WAKEUP is found in
@@ -1765,7 +1765,7 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
 	int error = -EINVAL;
 	struct sem_array *sma;
 	struct sembuf fast_sops[SEMOPM_FAST];
-	struct sembuf* sops = fast_sops, *sop;
+	struct sembuf *sops = fast_sops, *sop;
 	struct sem_undo *un;
 	int undos = 0, alter = 0, max, locknum;
 	struct sem_queue queue;
@@ -1779,13 +1779,13 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
 		return -EINVAL;
 	if (nsops > ns->sc_semopm)
 		return -E2BIG;
-	if(nsops > SEMOPM_FAST) {
-		sops = kmalloc(sizeof(*sops)*nsops,GFP_KERNEL);
-		if(sops==NULL)
+	if (nsops > SEMOPM_FAST) {
+		sops = kmalloc(sizeof(*sops)*nsops, GFP_KERNEL);
+		if (sops == NULL)
 			return -ENOMEM;
 	}
-	if (copy_from_user (sops, tsops, nsops * sizeof(*tsops))) {
-		error=-EFAULT;
+	if (copy_from_user(sops, tsops, nsops * sizeof(*tsops))) {
+		error =  -EFAULT;
 		goto out_free;
 	}
 	if (timeout) {
@@ -1846,7 +1846,15 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
 
 	error = -EIDRM;
 	locknum = sem_lock(sma, sops, nsops);
-	if (sma->sem_perm.deleted)
+	/*
+	 * We eventually might perform the following check in a lockless
+	 * fashion, considering ipc_valid_object() locking constraints.
+	 * If nsops == 1 and there is no contention for sem_perm.lock, then
+	 * only a per-semaphore lock is held and it's OK to proceed with the
+	 * check below. More details on the fine grained locking scheme
+	 * entangled here and why it's RMID race safe on comments at sem_lock()
+	 */
+	if (!ipc_valid_object(&sma->sem_perm))
 		goto out_unlock_free;
 	/*
 	 * semid identifiers are not unique - find_alloc_undo may have
@@ -1959,10 +1967,8 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
 	 * If queue.status != -EINTR we are woken up by another process.
 	 * Leave without unlink_queue(), but with sem_unlock().
 	 */
-
-	if (error != -EINTR) {
+	if (error != -EINTR)
 		goto out_unlock_free;
-	}
 
 	/*
 	 * If an interrupt occurred we have to clean up the queue
@@ -1984,7 +1990,7 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
 	rcu_read_unlock();
 	wake_up_sem_queue_do(&tasks);
 out_free:
-	if(sops != fast_sops)
+	if (sops != fast_sops)
 		kfree(sops);
 	return error;
 }
@@ -2068,7 +2074,7 @@ void exit_sem(struct task_struct *tsk)
 
 		sem_lock(sma, NULL, -1);
 		/* exit_sem raced with IPC_RMID, nothing to do */
-		if (sma->sem_perm.deleted) {
+		if (!ipc_valid_object(&sma->sem_perm)) {
 			sem_unlock(sma, -1);
 			rcu_read_unlock();
 			continue;
@@ -2093,7 +2099,7 @@ void exit_sem(struct task_struct *tsk)
 
 		/* perform adjustments registered in un */
 		for (i = 0; i < sma->sem_nsems; i++) {
-			struct sem * semaphore = &sma->sem_base[i];
+			struct sem *semaphore = &sma->sem_base[i];
 			if (un->semadj[i]) {
 				semaphore->semval += un->semadj[i];
 				/*

ipc/shm.c

@@ -67,7 +67,7 @@ static const struct vm_operations_struct shm_vm_ops;
 static int newseg(struct ipc_namespace *, struct ipc_params *);
 static void shm_open(struct vm_area_struct *vma);
 static void shm_close(struct vm_area_struct *vma);
-static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp);
+static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp);
 #ifdef CONFIG_PROC_FS
 static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
 #endif
@@ -91,7 +91,7 @@ static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
 	struct shmid_kernel *shp;
 	shp = container_of(ipcp, struct shmid_kernel, shm_perm);
 
-	if (shp->shm_nattch){
+	if (shp->shm_nattch) {
 		shp->shm_perm.mode |= SHM_DEST;
 		/* Do not find it any more */
 		shp->shm_perm.key = IPC_PRIVATE;
@@ -116,7 +116,7 @@ static int __init ipc_ns_init(void)
 
 pure_initcall(ipc_ns_init);
 
-void __init shm_init (void)
+void __init shm_init(void)
 {
 	ipc_init_proc_interface("sysvipc/shm",
 #if BITS_PER_LONG <= 32
@@ -248,7 +248,7 @@ static bool shm_may_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
  */
 static void shm_close(struct vm_area_struct *vma)
 {
-	struct file * file = vma->vm_file;
+	struct file *file = vma->vm_file;
 	struct shm_file_data *sfd = shm_file_data(file);
 	struct shmid_kernel *shp;
 	struct ipc_namespace *ns = sfd->ns;
@@ -379,7 +379,7 @@ static struct mempolicy *shm_get_policy(struct vm_area_struct *vma,
 }
 #endif
 
-static int shm_mmap(struct file * file, struct vm_area_struct * vma)
+static int shm_mmap(struct file *file, struct vm_area_struct *vma)
 {
 	struct shm_file_data *sfd = shm_file_data(file);
 	int ret;
@@ -477,7 +477,6 @@ static const struct vm_operations_struct shm_vm_ops = {
  *
  * Called with shm_ids.rwsem held as a writer.
  */
-
 static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
 {
 	key_t key = params->key;
@@ -486,7 +485,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
 	int error;
 	struct shmid_kernel *shp;
 	size_t numpages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
-	struct file * file;
+	struct file *file;
 	char name[13];
 	int id;
 	vm_flags_t acctflag = 0;
@@ -512,7 +511,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
 		return error;
 	}
 
-	sprintf (name, "SYSV%08x", key);
+	sprintf(name, "SYSV%08x", key);
 	if (shmflg & SHM_HUGETLB) {
 		struct hstate *hs;
 		size_t hugesize;
@@ -628,7 +627,7 @@ SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg)
 
 static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
 {
-	switch(version) {
+	switch (version) {
 	case IPC_64:
 		return copy_to_user(buf, in, sizeof(*in));
 	case IPC_OLD:
@@ -655,7 +654,7 @@ static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_
 static inline unsigned long
 copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
 {
-	switch(version) {
+	switch (version) {
 	case IPC_64:
 		if (copy_from_user(out, buf, sizeof(*out)))
 			return -EFAULT;
@@ -680,14 +679,14 @@ copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
 
 static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version)
 {
-	switch(version) {
+	switch (version) {
 	case IPC_64:
 		return copy_to_user(buf, in, sizeof(*in));
 	case IPC_OLD:
 	    {
 		struct shminfo out;
 
-		if(in->shmmax > INT_MAX)
+		if (in->shmmax > INT_MAX)
 			out.shmmax = INT_MAX;
 		else
 			out.shmmax = (int)in->shmmax;
@@ -846,14 +845,14 @@ static int shmctl_nolock(struct ipc_namespace *ns, int shmid,
 		shminfo.shmall = ns->shm_ctlall;
 
 		shminfo.shmmin = SHMMIN;
-		if(copy_shminfo_to_user (buf, &shminfo, version))
+		if (copy_shminfo_to_user(buf, &shminfo, version))
 			return -EFAULT;
 
 		down_read(&shm_ids(ns).rwsem);
 		err = ipc_get_maxid(&shm_ids(ns));
 		up_read(&shm_ids(ns).rwsem);
 
-		if(err<0)
+		if (err < 0)
 			err = 0;
 		goto out;
 	}
@@ -864,7 +863,7 @@ static int shmctl_nolock(struct ipc_namespace *ns, int shmid,
 		memset(&shm_info, 0, sizeof(shm_info));
 		down_read(&shm_ids(ns).rwsem);
 		shm_info.used_ids = shm_ids(ns).in_use;
-		shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp);
+		shm_get_stat(ns, &shm_info.shm_rss, &shm_info.shm_swp);
 		shm_info.shm_tot = ns->shm_tot;
 		shm_info.swap_attempts = 0;
 		shm_info.swap_successes = 0;
@@ -975,6 +974,13 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
 			goto out_unlock1;
 
 		ipc_lock_object(&shp->shm_perm);
+
+		/* check if shm_destroy() is tearing down shp */
+		if (!ipc_valid_object(&shp->shm_perm)) {
+			err = -EIDRM;
+			goto out_unlock0;
+		}
+
 		if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {
 			kuid_t euid = current_euid();
 			if (!uid_eq(euid, shp->shm_perm.uid) &&
@@ -989,13 +995,6 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
 		}
 
 		shm_file = shp->shm_file;
-
-		/* check if shm_destroy() is tearing down shp */
-		if (shm_file == NULL) {
-			err = -EIDRM;
-			goto out_unlock0;
-		}
-
 		if (is_file_hugepages(shm_file))
 			goto out_unlock0;
 
@@ -1047,7 +1046,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr,
 	struct shmid_kernel *shp;
 	unsigned long addr;
 	unsigned long size;
-	struct file * file;
+	struct file *file;
 	int    err;
 	unsigned long flags;
 	unsigned long prot;
@@ -1116,7 +1115,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr,
 	ipc_lock_object(&shp->shm_perm);
 
 	/* check if shm_destroy() is tearing down shp */
-	if (shp->shm_file == NULL) {
+	if (!ipc_valid_object(&shp->shm_perm)) {
 		ipc_unlock_object(&shp->shm_perm);
 		err = -EIDRM;
 		goto out_unlock;

ipc/util.c

@@ -110,15 +110,15 @@ static struct notifier_block ipc_memory_nb = {
 };
 
 /**
- *	ipc_init	-	initialise IPC subsystem
+ * ipc_init - initialise ipc subsystem
+ *
+ * The various sysv ipc resources (semaphores, messages and shared
+ * memory) are initialised.
  *
- *	The various system5 IPC resources (semaphores, messages and shared
- *	memory) are initialised
  * A callback routine is registered into the memory hotplug notifier
  * chain: since msgmni scales to lowmem this callback routine will be
  * called upon successful memory add / remove to recompute msmgni.
  */
- 
 static int __init ipc_init(void)
 {
 	sem_init();
@@ -131,35 +131,25 @@ static int __init ipc_init(void)
 __initcall(ipc_init);
 
 /**
- *	ipc_init_ids		-	initialise IPC identifiers
- *	@ids: Identifier set
+ * ipc_init_ids	- initialise ipc identifiers
+ * @ids: ipc identifier set
  *
  * Set up the sequence range to use for the ipc identifier range (limited
  * below IPCMNI) then initialise the ids idr.
  */
- 
 void ipc_init_ids(struct ipc_ids *ids)
 {
-	init_rwsem(&ids->rwsem);
-
 	ids->in_use = 0;
 	ids->seq = 0;
 	ids->next_id = -1;
-	{
-		int seq_limit = INT_MAX/SEQ_MULTIPLIER;
-		if (seq_limit > USHRT_MAX)
-			ids->seq_max = USHRT_MAX;
-		 else
-		 	ids->seq_max = seq_limit;
-	}
-
+	init_rwsem(&ids->rwsem);
 	idr_init(&ids->ipcs_idr);
 }
 
 #ifdef CONFIG_PROC_FS
 static const struct file_operations sysvipc_proc_fops;
 /**
- *	ipc_init_proc_interface	-  Create a proc interface for sysipc types using a seq_file interface.
+ * ipc_init_proc_interface -  create a proc interface for sysipc types using a seq_file interface.
  * @path: Path in procfs
  * @header: Banner to be printed at the beginning of the file.
  * @ids: ipc id table to iterate.
@@ -184,23 +174,21 @@ void __init ipc_init_proc_interface(const char *path, const char *header,
 			       NULL,           /* parent dir */
 			       &sysvipc_proc_fops,
 			       iface);
-	if (!pde) {
+	if (!pde)
 		kfree(iface);
-	}
 }
 #endif
 
 /**
  * ipc_findkey	- find a key in an ipc identifier set
- *	@ids: Identifier set
- *	@key: The key to find
+ * @ids: ipc identifier set
+ * @key: key to find
+ *	
+ * Returns the locked pointer to the ipc structure if found or NULL
+ * otherwise. If key is found ipc points to the owning ipc structure
  *
- *	Requires ipc_ids.rwsem locked.
- *	Returns the LOCKED pointer to the ipc structure if found or NULL
- *	if not.
- *	If key is found ipc points to the owning ipc structure
+ * Called with ipc_ids.rwsem held.
  */
- 
 static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
 {
 	struct kern_ipc_perm *ipc;
@@ -228,11 +216,10 @@ static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
 
 /**
  * ipc_get_maxid - get the last assigned id
- *	@ids: IPC identifier set
+ * @ids: ipc identifier set
  *
  * Called with ipc_ids.rwsem held.
  */
-
 int ipc_get_maxid(struct ipc_ids *ids)
 {
 	struct kern_ipc_perm *ipc;
@@ -258,19 +245,19 @@ int ipc_get_maxid(struct ipc_ids *ids)
 }
 
 /**
- *	ipc_addid 	-	add an IPC identifier
- *	@ids: IPC identifier set
- *	@new: new IPC permission set
+ * ipc_addid - add an ipc identifier
+ * @ids: ipc identifier set
+ * @new: new ipc permission set
  * @size: limit for the number of used ids
  *
- *	Add an entry 'new' to the IPC ids idr. The permissions object is
+ * Add an entry 'new' to the ipc ids idr. The permissions object is
  * initialised and the first free entry is set up and the id assigned
  * is returned. The 'new' entry is returned in a locked state on success.
  * On failure the entry is not locked and a negative err-code is returned.
  *
  * Called with writer ipc_ids.rwsem held.
  */
-int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
+int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int size)
 {
 	kuid_t euid;
 	kgid_t egid;
@@ -286,7 +273,7 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
 	idr_preload(GFP_KERNEL);
 
 	spin_lock_init(&new->lock);
-	new->deleted = 0;
+	new->deleted = false;
 	rcu_read_lock();
 	spin_lock(&new->lock);
 
@@ -308,7 +295,7 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
 
 	if (next_id < 0) {
 		new->seq = ids->seq++;
-		if (ids->seq > ids->seq_max)
+		if (ids->seq > IPCID_SEQ_MAX)
 			ids->seq = 0;
 	} else {
 		new->seq = ipcid_to_seqx(next_id);
@@ -321,8 +308,8 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
 
 /**
  * ipcget_new -	create a new ipc object
- *	@ns: namespace
- *	@ids: IPC identifer set
+ * @ns: ipc namespace
+ * @ids: ipc identifer set
  * @ops: the actual creation routine to call
  * @params: its parameters
  *
@@ -341,17 +328,17 @@ static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
 }
 
 /**
- *	ipc_check_perms	-	check security and permissions for an IPC
- *	@ns: IPC namespace
+ * ipc_check_perms - check security and permissions for an ipc object
+ * @ns: ipc namespace
  * @ipcp: ipc permission set
  * @ops: the actual security routine to call
  * @params: its parameters
  *
  * This routine is called by sys_msgget(), sys_semget() and sys_shmget()
  * when the key is not IPC_PRIVATE and that key already exists in the
- *      ids IDR.
+ * ds IDR.
  *
- *	On success, the IPC id is returned.
+ * On success, the ipc id is returned.
  *
  * It is called with ipc_ids.rwsem and ipcp->lock held.
  */
@@ -375,8 +362,8 @@ static int ipc_check_perms(struct ipc_namespace *ns,
 
 /**
  * ipcget_public - get an ipc object or create a new one
- *	@ns: namespace
- *	@ids: IPC identifer set
+ * @ns: ipc namespace
+ * @ids: ipc identifer set
  * @ops: the actual creation routine to call
  * @params: its parameters
  *
@@ -431,25 +418,20 @@ static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
 
 
 /**
- *	ipc_rmid	-	remove an IPC identifier
- *	@ids: IPC identifier set
+ * ipc_rmid - remove an ipc identifier
+ * @ids: ipc identifier set
  * @ipcp: ipc perm structure containing the identifier to remove
  *
  * ipc_ids.rwsem (as a writer) and the spinlock for this ID are held
  * before this function is called, and remain locked on the exit.
  */
- 
 void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
 {
 	int lid = ipcid_to_idx(ipcp->id);
 
 	idr_remove(&ids->ipcs_idr, lid);
-
 	ids->in_use--;
-
-	ipcp->deleted = 1;
-
-	return;
+	ipcp->deleted = true;
 }
 
 /**
@@ -459,11 +441,10 @@ void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
  * Allocate memory from the appropriate pools and return a pointer to it.
  * NULL is returned if the allocation fails
  */
- 
 void *ipc_alloc(int size)
 {
 	void *out;
-	if(size > PAGE_SIZE)
+	if (size > PAGE_SIZE)
 		out = vmalloc(size);
 	else
 		out = kmalloc(size, GFP_KERNEL);
@@ -478,10 +459,9 @@ void *ipc_alloc(int size)
  * Free a block created with ipc_alloc(). The caller must know the size
  * used in the allocation call.
  */
-
-void ipc_free(void* ptr, int size)
+void ipc_free(void *ptr, int size)
 {
-	if(size > PAGE_SIZE)
+	if (size > PAGE_SIZE)
 		vfree(ptr);
 	else
 		kfree(ptr);
@@ -534,17 +514,16 @@ void ipc_rcu_free(struct rcu_head *head)
 }
 
 /**
- *	ipcperms	-	check IPC permissions
- *	@ns: IPC namespace
- *	@ipcp: IPC permission set
- *	@flag: desired permission set.
+ * ipcperms - check ipc permissions
+ * @ns: ipc namespace
+ * @ipcp: ipc permission set
+ * @flag: desired permission set
  *
  * Check user, group, other permissions for access
  * to ipc resources. return 0 if allowed
  *
  * @flag will most probably be 0 or S_...UGO from <linux/stat.h>
  */
- 
 int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag)
 {
 	kuid_t euid = current_euid();
@@ -574,14 +553,12 @@ int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag)
 /**
  * kernel_to_ipc64_perm	- convert kernel ipc permissions to user
  * @in: kernel permissions
- *	@out: new style IPC permissions
+ * @out: new style ipc permissions
  *
  * Turn the kernel object @in into a set of permissions descriptions
  * for returning to userspace (@out).
  */
- 
-
-void kernel_to_ipc64_perm (struct kern_ipc_perm *in, struct ipc64_perm *out)
+void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out)
 {
 	out->key	= in->key;
 	out->uid	= from_kuid_munged(current_user_ns(), in->uid);
@@ -594,14 +571,13 @@ void kernel_to_ipc64_perm (struct kern_ipc_perm *in, struct ipc64_perm *out)
 
 /**
  * ipc64_perm_to_ipc_perm - convert new ipc permissions to old
- *	@in: new style IPC permissions
- *	@out: old style IPC permissions
+ * @in: new style ipc permissions
+ * @out: old style ipc permissions
  *
  * Turn the new style permissions object @in into a compatibility
  * object and store it into the @out pointer.
  */
- 
-void ipc64_perm_to_ipc_perm (struct ipc64_perm *in, struct ipc_perm *out)
+void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out)
 {
 	out->key	= in->key;
 	SET_UID(out->uid, in->uid);
@@ -635,8 +611,8 @@ struct kern_ipc_perm *ipc_obtain_object(struct ipc_ids *ids, int id)
 }
 
 /**
- * ipc_lock - Lock an ipc structure without rwsem held
- * @ids: IPC identifier set
+ * ipc_lock - lock an ipc structure without rwsem held
+ * @ids: ipc identifier set
  * @id: ipc id to look for
  *
  * Look for an id in the ipc ids idr and lock the associated ipc object.
@@ -657,7 +633,7 @@ struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
 	/* ipc_rmid() may have already freed the ID while ipc_lock
 	 * was spinning: here verify that the structure is still valid
 	 */
-	if (!out->deleted)
+	if (ipc_valid_object(out))
 		return out;
 
 	spin_unlock(&out->lock);
@@ -693,11 +669,11 @@ struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id)
 
 /**
  * ipcget - Common sys_*get() code
- * @ns : namsepace
- * @ids : IPC identifier set
- * @ops : operations to be called on ipc object creation, permission checks
+ * @ns: namsepace
+ * @ids: ipc identifier set
+ * @ops: operations to be called on ipc object creation, permission checks
  *       and further checks
- * @params : the parameters needed by the previous operations.
+ * @params: the parameters needed by the previous operations.
  *
  * Common routine called by sys_msgget(), sys_semget() and sys_shmget().
  */
@@ -711,7 +687,7 @@ int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
 }
 
 /**
- * ipc_update_perm - update the permissions of an IPC.
+ * ipc_update_perm - update the permissions of an ipc object
  * @in:  the permission given as input.
  * @out: the permission of the ipc to set.
  */
@@ -732,7 +708,7 @@ int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out)
 
 /**
  * ipcctl_pre_down_nolock - retrieve an ipc and check permissions for some IPC_XXX cmd
- * @ns:  the ipc namespace
+ * @ns:  ipc namespace
  * @ids:  the table of ids where to look for the ipc
  * @id:   the id of the ipc to retrieve
  * @cmd:  the cmd to check
@@ -779,15 +755,14 @@ struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns,
 
 
 /**
- *	ipc_parse_version	-	IPC call version
+ * ipc_parse_version - ipc call version
  * @cmd: pointer to command
  *
  * Return IPC_64 for new style IPC and IPC_OLD for old style IPC.
  * The @cmd value is turned from an encoding command and version into
  * just the command code.
  */
- 
-int ipc_parse_version (int *cmd)
+int ipc_parse_version(int *cmd)
 {
 	if (*cmd & IPC_64) {
 		*cmd ^= IPC_64;
@@ -824,7 +799,7 @@ static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
 	if (total >= ids->in_use)
 		return NULL;
 
-	for ( ; pos < IPCMNI; pos++) {
+	for (; pos < IPCMNI; pos++) {
 		ipc = idr_find(&ids->ipcs_idr, pos);
 		if (ipc != NULL) {
 			*new_pos = pos + 1;
@@ -927,8 +902,10 @@ static int sysvipc_proc_open(struct inode *inode, struct file *file)
 		goto out;
 
 	ret = seq_open(file, &sysvipc_proc_seqops);
-	if (ret)
-		goto out_kfree;
+	if (ret) {
+		kfree(iter);
+		goto out;
+	}
 
 	seq = file->private_data;
 	seq->private = iter;
@@ -937,9 +914,6 @@ static int sysvipc_proc_open(struct inode *inode, struct file *file)
 	iter->ns    = get_ipc_ns(current->nsproxy->ipc_ns);
 out:
 	return ret;
-out_kfree:
-	kfree(iter);
-	goto out;
 }
 
 static int sysvipc_proc_release(struct inode *inode, struct file *file)

ipc/util.h

@@ -15,9 +15,9 @@
 
 #define SEQ_MULTIPLIER	(IPCMNI)
 
-void sem_init (void);
-void msg_init (void);
-void shm_init (void);
+void sem_init(void);
+void msg_init(void);
+void shm_init(void);
 
 struct ipc_namespace;
 
@@ -100,6 +100,7 @@ void __init ipc_init_proc_interface(const char *path, const char *header,
 
 #define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER)
 #define ipcid_to_seqx(id) ((id) / SEQ_MULTIPLIER)
+#define IPCID_SEQ_MAX min_t(int, INT_MAX/SEQ_MULTIPLIER, USHRT_MAX)
 
 /* must be called with ids->rwsem acquired for writing */
 int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
@@ -116,8 +117,8 @@ int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flg);
 /* for rare, potentially huge allocations.
  * both function can sleep
  */
-void* ipc_alloc(int size);
-void ipc_free(void* ptr, int size);
+void *ipc_alloc(int size);
+void ipc_free(void *ptr, int size);
 
 /*
  * For allocation that need to be freed by RCU.
@@ -125,7 +126,7 @@ void ipc_free(void* ptr, int size);
  * getref increases the refcount, the putref call that reduces the recount
  * to 0 schedules the rcu destruction. Caller must guarantee locking.
  */
-void* ipc_rcu_alloc(int size);
+void *ipc_rcu_alloc(int size);
 int ipc_rcu_getref(void *ptr);
 void ipc_rcu_putref(void *ptr, void (*func)(struct rcu_head *head));
 void ipc_rcu_free(struct rcu_head *head);
@@ -144,7 +145,7 @@ struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns,
   /* On IA-64, we always use the "64-bit version" of the IPC structures.  */ 
 # define ipc_parse_version(cmd)	IPC_64
 #else
-int ipc_parse_version (int *cmd);
+int ipc_parse_version(int *cmd);
 #endif
 
 extern void free_msg(struct msg_msg *msg);
@@ -185,6 +186,19 @@ static inline void ipc_unlock(struct kern_ipc_perm *perm)
 	rcu_read_unlock();
 }
 
+/*
+ * ipc_valid_object() - helper to sort out IPC_RMID races for codepaths
+ * where the respective ipc_ids.rwsem is not being held down.
+ * Checks whether the ipc object is still around or if it's gone already, as
+ * ipc_rmid() may have already freed the ID while the ipc lock was spinning.
+ * Needs to be called with kern_ipc_perm.lock held -- exception made for one
+ * checkpoint case at sys_semtimedop() as noted in code commentary.
+ */
+static inline bool ipc_valid_object(struct kern_ipc_perm *perm)
+{
+	return !perm->deleted;
+}
+
 struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id);
 int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
 			struct ipc_ops *ops, struct ipc_params *params);

kernel/kexec.c

@@ -1537,7 +1537,7 @@ void vmcoreinfo_append_str(const char *fmt, ...)
 	size_t r;
 
 	va_start(args, fmt);
-	r = vsnprintf(buf, sizeof(buf), fmt, args);
+	r = vscnprintf(buf, sizeof(buf), fmt, args);
 	va_end(args);
 
 	r = min(r, vmcoreinfo_max_size - vmcoreinfo_size);

kernel/softirq.c

@@ -8,6 +8,8 @@
  *	Rewritten. Old one was good in 2.2, but in 2.3 it was immoral. --ANK (990903)
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/export.h>
 #include <linux/kernel_stat.h>
 #include <linux/interrupt.h>
@@ -54,7 +56,7 @@ static struct softirq_action softirq_vec[NR_SOFTIRQS] __cacheline_aligned_in_smp
 
 DEFINE_PER_CPU(struct task_struct *, ksoftirqd);
 
-char *softirq_to_name[NR_SOFTIRQS] = {
+const char * const softirq_to_name[NR_SOFTIRQS] = {
 	"HI", "TIMER", "NET_TX", "NET_RX", "BLOCK", "BLOCK_IOPOLL",
 	"TASKLET", "SCHED", "HRTIMER", "RCU"
 };
@@ -136,7 +138,6 @@ void _local_bh_enable(void)
 	WARN_ON_ONCE(in_irq());
 	__local_bh_enable(SOFTIRQ_DISABLE_OFFSET);
 }
-
 EXPORT_SYMBOL(_local_bh_enable);
 
 void __local_bh_enable_ip(unsigned long ip, unsigned int cnt)
@@ -229,6 +230,7 @@ asmlinkage void __do_softirq(void)
 	struct softirq_action *h;
 	bool in_hardirq;
 	__u32 pending;
+	int softirq_bit;
 	int cpu;
 
 	/*
@@ -253,10 +255,14 @@ asmlinkage void __do_softirq(void)
 
 	h = softirq_vec;
 
-	do {
-		if (pending & 1) {
-			unsigned int vec_nr = h - softirq_vec;
-			int prev_count = preempt_count();
+	while ((softirq_bit = ffs(pending))) {
+		unsigned int vec_nr;
+		int prev_count;
+
+		h += softirq_bit - 1;
+
+		vec_nr = h - softirq_vec;
+		prev_count = preempt_count();
 
 		kstat_incr_softirqs_this_cpu(vec_nr);
 
@@ -264,19 +270,15 @@ asmlinkage void __do_softirq(void)
 		h->action(h);
 		trace_softirq_exit(vec_nr);
 		if (unlikely(prev_count != preempt_count())) {
-				printk(KERN_ERR "huh, entered softirq %u %s %p"
-				       "with preempt_count %08x,"
-				       " exited with %08x?\n", vec_nr,
-				       softirq_to_name[vec_nr], h->action,
+			pr_err("huh, entered softirq %u %s %p with preempt_count %08x, exited with %08x?\n",
+			       vec_nr, softirq_to_name[vec_nr], h->action,
 			       prev_count, preempt_count());
 			preempt_count_set(prev_count);
 		}
-
 		rcu_bh_qs(cpu);
-		}
 		h++;
-		pending >>= 1;
-	} while (pending);
+		pending >>= softirq_bit;
+	}
 
 	local_irq_disable();
 
@@ -433,8 +435,7 @@ void open_softirq(int nr, void (*action)(struct softirq_action *))
 /*
  * Tasklets
  */
-struct tasklet_head
-{
+struct tasklet_head {
 	struct tasklet_struct *head;
 	struct tasklet_struct **tail;
 };
@@ -453,7 +454,6 @@ void __tasklet_schedule(struct tasklet_struct *t)
 	raise_softirq_irqoff(TASKLET_SOFTIRQ);
 	local_irq_restore(flags);
 }
-
 EXPORT_SYMBOL(__tasklet_schedule);
 
 void __tasklet_hi_schedule(struct tasklet_struct *t)
@@ -467,7 +467,6 @@ void __tasklet_hi_schedule(struct tasklet_struct *t)
 	raise_softirq_irqoff(HI_SOFTIRQ);
 	local_irq_restore(flags);
 }
-
 EXPORT_SYMBOL(__tasklet_hi_schedule);
 
 void __tasklet_hi_schedule_first(struct tasklet_struct *t)
@@ -478,7 +477,6 @@ void __tasklet_hi_schedule_first(struct tasklet_struct *t)
 	__this_cpu_write(tasklet_hi_vec.head, t);
 	__raise_softirq_irqoff(HI_SOFTIRQ);
 }
-
 EXPORT_SYMBOL(__tasklet_hi_schedule_first);
 
 static void tasklet_action(struct softirq_action *a)
@@ -498,7 +496,8 @@ static void tasklet_action(struct softirq_action *a)
 
 		if (tasklet_trylock(t)) {
 			if (!atomic_read(&t->count)) {
-				if (!test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
+				if (!test_and_clear_bit(TASKLET_STATE_SCHED,
+							&t->state))
 					BUG();
 				t->func(t->data);
 				tasklet_unlock(t);
@@ -533,7 +532,8 @@ static void tasklet_hi_action(struct softirq_action *a)
 
 		if (tasklet_trylock(t)) {
 			if (!atomic_read(&t->count)) {
-				if (!test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
+				if (!test_and_clear_bit(TASKLET_STATE_SCHED,
+							&t->state))
 					BUG();
 				t->func(t->data);
 				tasklet_unlock(t);
@@ -551,7 +551,6 @@ static void tasklet_hi_action(struct softirq_action *a)
 	}
 }
 
-
 void tasklet_init(struct tasklet_struct *t,
 		  void (*func)(unsigned long), unsigned long data)
 {
@@ -561,13 +560,12 @@ void tasklet_init(struct tasklet_struct *t,
 	t->func = func;
 	t->data = data;
 }
-
 EXPORT_SYMBOL(tasklet_init);
 
 void tasklet_kill(struct tasklet_struct *t)
 {
 	if (in_interrupt())
-		printk("Attempt to kill tasklet from interrupt\n");
+		pr_notice("Attempt to kill tasklet from interrupt\n");
 
 	while (test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) {
 		do {
@@ -577,7 +575,6 @@ void tasklet_kill(struct tasklet_struct *t)
 	tasklet_unlock_wait(t);
 	clear_bit(TASKLET_STATE_SCHED, &t->state);
 }
-
 EXPORT_SYMBOL(tasklet_kill);
 
 /*
@@ -727,8 +724,7 @@ static void takeover_tasklets(unsigned int cpu)
 }
 #endif /* CONFIG_HOTPLUG_CPU */
 
-static int cpu_callback(struct notifier_block *nfb,
-				  unsigned long action,
+static int cpu_callback(struct notifier_block *nfb, unsigned long action,
 			void *hcpu)
 {
 	switch (action) {

lib/dynamic_debug.c

@@ -268,14 +268,12 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
  */
 static inline int parse_lineno(const char *str, unsigned int *val)
 {
-	char *end = NULL;
 	BUG_ON(str == NULL);
 	if (*str == '\0') {
 		*val = 0;
 		return 0;
 	}
-	*val = simple_strtoul(str, &end, 10);
-	if (end == NULL || end == str || *end != '\0') {
+	if (kstrtouint(str, 10, val) < 0) {
 		pr_err("bad line-number: %s\n", str);
 		return -EINVAL;
 	}
@@ -348,14 +346,14 @@ static int ddebug_parse_query(char *words[], int nwords,
 			}
 			if (last)
 				*last++ = '\0';
-			if (parse_lineno(first, &query->first_lineno) < 0) {
-				pr_err("line-number is <0\n");
+			if (parse_lineno(first, &query->first_lineno) < 0)
 				return -EINVAL;
-			}
 			if (last) {
 				/* range <first>-<last> */
-				if (parse_lineno(last, &query->last_lineno)
-				    < query->first_lineno) {
+				if (parse_lineno(last, &query->last_lineno) < 0)
+					return -EINVAL;
+
+				if (query->last_lineno < query->first_lineno) {
 					pr_err("last-line:%d < 1st-line:%d\n",
 						query->last_lineno,
 						query->first_lineno);

lib/swiotlb.c

@@ -172,7 +172,7 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
 	/*
 	 * Get the overflow emergency buffer
 	 */
-	v_overflow_buffer = memblock_virt_alloc_nopanic(
+	v_overflow_buffer = memblock_virt_alloc_low_nopanic(
 						PAGE_ALIGN(io_tlb_overflow),
 						PAGE_SIZE);
 	if (!v_overflow_buffer)
@@ -220,7 +220,7 @@ swiotlb_init(int verbose)
 	bytes = io_tlb_nslabs << IO_TLB_SHIFT;
 
 	/* Get IO TLB memory from the low pages */
-	vstart = memblock_virt_alloc_nopanic(PAGE_ALIGN(bytes), PAGE_SIZE);
+	vstart = memblock_virt_alloc_low_nopanic(PAGE_ALIGN(bytes), PAGE_SIZE);
 	if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, verbose))
 		return;
 

mm/memblock.c

@@ -984,9 +984,6 @@ static phys_addr_t __init memblock_alloc_base_nid(phys_addr_t size,
 	if (!align)
 		align = SMP_CACHE_BYTES;
 
-	/* align @size to avoid excessive fragmentation on reserved array */
-	size = round_up(size, align);
-
 	found = memblock_find_in_range_node(size, align, 0, max_addr, nid);
 	if (found && !memblock_reserve(found, size))
 		return found;
@@ -1080,9 +1077,6 @@ static void * __init memblock_virt_alloc_internal(
 	if (!align)
 		align = SMP_CACHE_BYTES;
 
-	/* align @size to avoid excessive fragmentation on reserved array */
-	size = round_up(size, align);
-
 again:
 	alloc = memblock_find_in_range_node(size, align, min_addr, max_addr,
 					    nid);

mm/migrate.c

@@ -1548,8 +1548,6 @@ static struct page *alloc_misplaced_dst_page(struct page *page,
 					  __GFP_NOMEMALLOC | __GFP_NORETRY |
 					  __GFP_NOWARN) &
 					 ~GFP_IOFS, 0);
-	if (newpage)
-		page_cpupid_xchg_last(newpage, page_cpupid_last(page));
 
 	return newpage;
 }

mm/mm_init.c

@@ -202,4 +202,4 @@ static int __init mm_sysfs_init(void)
 
 	return 0;
 }
-pure_initcall(mm_sysfs_init);
+postcore_initcall(mm_sysfs_init);

mm/vmalloc.c

@@ -220,12 +220,12 @@ int is_vmalloc_or_module_addr(const void *x)
 }
 
 /*
- * Walk a vmap address to the physical pfn it maps to.
+ * Walk a vmap address to the struct page it maps.
  */
-unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
+struct page *vmalloc_to_page(const void *vmalloc_addr)
 {
 	unsigned long addr = (unsigned long) vmalloc_addr;
-	unsigned long pfn = 0;
+	struct page *page = NULL;
 	pgd_t *pgd = pgd_offset_k(addr);
 
 	/*
@@ -244,23 +244,23 @@ unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
 				ptep = pte_offset_map(pmd, addr);
 				pte = *ptep;
 				if (pte_present(pte))
-					pfn = pte_pfn(pte);
+					page = pte_page(pte);
 				pte_unmap(ptep);
 			}
 		}
 	}
-	return pfn;
+	return page;
 }
-EXPORT_SYMBOL(vmalloc_to_pfn);
+EXPORT_SYMBOL(vmalloc_to_page);
 
 /*
- * Map a vmalloc()-space virtual address to the struct page.
+ * Map a vmalloc()-space virtual address to the physical page frame number.
  */
-struct page *vmalloc_to_page(const void *vmalloc_addr)
+unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
 {
-	return pfn_to_page(vmalloc_to_pfn(vmalloc_addr));
+	return page_to_pfn(vmalloc_to_page(vmalloc_addr));
 }
-EXPORT_SYMBOL(vmalloc_to_page);
+EXPORT_SYMBOL(vmalloc_to_pfn);
 
 
 /*** Global kva allocator ***/

scripts/checkpatch.pl

@@ -2665,6 +2665,15 @@ sub process {
 				$herecurr);
                }
 
+# check for function declarations without arguments like "int foo()"
+		if ($line =~ /(\b$Type\s+$Ident)\s*\(\s*\)/) {
+			if (ERROR("FUNCTION_WITHOUT_ARGS",
+				  "Bad function definition - $1() should probably be $1(void)\n" . $herecurr) &&
+			    $fix) {
+				$fixed[$linenr - 1] =~ s/(\b($Type)\s+($Ident))\s*\(\s*\)/$2 $3(void)/;
+			}
+		}
+
 # check for uses of DEFINE_PCI_DEVICE_TABLE
 		if ($line =~ /\bDEFINE_PCI_DEVICE_TABLE\s*\(\s*(\w+)\s*\)\s*=/) {
 			if (WARN("DEFINE_PCI_DEVICE_TABLE",