10 files changed, 126 insertions, 40 deletions

diff --git a/kernel/module.c b/kernel/module.c
index ba22484a987e..1f0657ae555b 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -51,6 +51,7 @@
 #include <linux/tracepoint.h>
 #include <linux/ftrace.h>
 #include <linux/async.h>
+#include <linux/percpu.h>
 
 #if 0
 #define DEBUGP printk
@@ -366,6 +367,34 @@ static struct module *find_module(const char *name)
 }
 
 #ifdef CONFIG_SMP
+
+#ifdef CONFIG_HAVE_DYNAMIC_PER_CPU_AREA
+
+static void *percpu_modalloc(unsigned long size, unsigned long align,
+                             const char *name)
+{
+        void *ptr;
+
+        if (align > PAGE_SIZE) {
+                printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
+                       name, align, PAGE_SIZE);
+                align = PAGE_SIZE;
+        }
+
+        ptr = __alloc_percpu(size, align);
+        if (!ptr)
+                printk(KERN_WARNING
+                       "Could not allocate %lu bytes percpu data\n", size);
+        return ptr;
+}
+
+static void percpu_modfree(void *freeme)
+{
+        free_percpu(freeme);
+}
+
+#else /* ... !CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */
+
 /* Number of blocks used and allocated. */
 static unsigned int pcpu_num_used, pcpu_num_allocated;
 /* Size of each block.  -ve means used. */
@@ -480,21 +509,6 @@ static void percpu_modfree(void *freeme)
         }
 }
 
-static unsigned int find_pcpusec(Elf_Ehdr *hdr,
-                                 Elf_Shdr *sechdrs,
-                                 const char *secstrings)
-{
-        return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
-}
-
-static void percpu_modcopy(void *pcpudest, const void *from, unsigned long size)
-{
-        int cpu;
-
-        for_each_possible_cpu(cpu)
-                memcpy(pcpudest + per_cpu_offset(cpu), from, size);
-}
-
 static int percpu_modinit(void)
 {
         pcpu_num_used = 2;
@@ -513,7 +527,26 @@ static int percpu_modinit(void)
         return 0;
 }
 __initcall(percpu_modinit);
+
+#endif /* CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */
+
+static unsigned int find_pcpusec(Elf_Ehdr *hdr,
+                                 Elf_Shdr *sechdrs,
+                                 const char *secstrings)
+{
+        return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
+}
+
+static void percpu_modcopy(void *pcpudest, const void *from, unsigned long size)
+{
+        int cpu;
+
+        for_each_possible_cpu(cpu)
+                memcpy(pcpudest + per_cpu_offset(cpu), from, size);
+}
+
 #else /* ... !CONFIG_SMP */
+
 static inline void *percpu_modalloc(unsigned long size, unsigned long align,
                                     const char *name)
 {
@@ -535,6 +568,7 @@ static inline void percpu_modcopy(void *pcpudst, const void *src,
         /* pcpusec should be 0, and size of that section should be 0. */
         BUG_ON(size != 0);
 }
+
 #endif /* CONFIG_SMP */
 
 #define MODINFO_ATTR(field)     \
diff --git a/kernel/rcuclassic.c b/kernel/rcuclassic.c
index bd5a9003497c..654c640a6b9c 100644
--- a/kernel/rcuclassic.c
+++ b/kernel/rcuclassic.c
@@ -679,8 +679,8 @@ int rcu_needs_cpu(int cpu)
 void rcu_check_callbacks(int cpu, int user)
 {
         if (user ||
-            (idle_cpu(cpu) && !in_softirq() &&
-                                hardirq_count() <= (1 << HARDIRQ_SHIFT))) {
+            (idle_cpu(cpu) && rcu_scheduler_active &&
+             !in_softirq() && hardirq_count() <= (1 << HARDIRQ_SHIFT))) {
 
                 /*
                  * Get here if this CPU took its interrupt from user
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index d92a76a881aa..cae8a059cf47 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -44,6 +44,7 @@
 #include <linux/cpu.h>
 #include <linux/mutex.h>
 #include <linux/module.h>
+#include <linux/kernel_stat.h>
 
 enum rcu_barrier {
         RCU_BARRIER_STD,
@@ -55,6 +56,7 @@ static DEFINE_PER_CPU(struct rcu_head, rcu_barrier_head) = {NULL};
 static atomic_t rcu_barrier_cpu_count;
 static DEFINE_MUTEX(rcu_barrier_mutex);
 static struct completion rcu_barrier_completion;
+int rcu_scheduler_active __read_mostly;
 
 /*
  * Awaken the corresponding synchronize_rcu() instance now that a
@@ -80,6 +82,10 @@ void wakeme_after_rcu(struct rcu_head  *head)
 void synchronize_rcu(void)
 {
         struct rcu_synchronize rcu;
+
+        if (rcu_blocking_is_gp())
+                return;
+
         init_completion(&rcu.completion);
         /* Will wake me after RCU finished. */
         call_rcu(&rcu.head, wakeme_after_rcu);
@@ -175,3 +181,9 @@ void __init rcu_init(void)
         __rcu_init();
 }
 
+void rcu_scheduler_starting(void)
+{
+        WARN_ON(num_online_cpus() != 1);
+        WARN_ON(nr_context_switches() > 0);
+        rcu_scheduler_active = 1;
+}
diff --git a/kernel/rcupreempt.c b/kernel/rcupreempt.c
index 33cfc50781f9..5d59e850fb71 100644
--- a/kernel/rcupreempt.c
+++ b/kernel/rcupreempt.c
@@ -1181,6 +1181,9 @@ void __synchronize_sched(void)
 {
         struct rcu_synchronize rcu;
 
+        if (num_online_cpus() == 1)
+                return;  /* blocking is gp if only one CPU! */
+
         init_completion(&rcu.completion);
         /* Will wake me after RCU finished. */
         call_rcu_sched(&rcu.head, wakeme_after_rcu);
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index b2fd602a6f6f..97ce31579ec0 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -948,8 +948,8 @@ static void rcu_do_batch(struct rcu_data *rdp)
 void rcu_check_callbacks(int cpu, int user)
 {
         if (user ||
-            (idle_cpu(cpu) && !in_softirq() &&
-                                hardirq_count() <= (1 << HARDIRQ_SHIFT))) {
+            (idle_cpu(cpu) && rcu_scheduler_active &&
+             !in_softirq() && hardirq_count() <= (1 << HARDIRQ_SHIFT))) {
 
                 /*
                  * Get here if this CPU took its interrupt from user
diff --git a/kernel/sched.c b/kernel/sched.c
index 7d97ff7c4478..0a76d0b6f215 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -223,7 +223,7 @@ static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
 {
         ktime_t now;
 
-        if (rt_bandwidth_enabled() && rt_b->rt_runtime == RUNTIME_INF)
+        if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
                 return;
 
         if (hrtimer_active(&rt_b->rt_period_timer))
@@ -9219,6 +9219,16 @@ static int sched_rt_global_constraints(void)
 
         return ret;
 }
+
+int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk)
+{
+        /* Don't accept realtime tasks when there is no way for them to run */
+        if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0)
+                return 0;
+
+        return 1;
+}
+
 #else /* !CONFIG_RT_GROUP_SCHED */
 static int sched_rt_global_constraints(void)
 {
@@ -9312,8 +9322,7 @@ cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
                       struct task_struct *tsk)
 {
 #ifdef CONFIG_RT_GROUP_SCHED
-        /* Don't accept realtime tasks when there is no way for them to run */
-        if (rt_task(tsk) && cgroup_tg(cgrp)->rt_bandwidth.rt_runtime == 0)
+        if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk))
                 return -EINVAL;
 #else
         /* We don't support RT-tasks being in separate groups */
@@ -9476,7 +9485,7 @@ cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
 
 static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu)
 {
-        u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu);
+        u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
         u64 data;
 
 #ifndef CONFIG_64BIT
@@ -9495,7 +9504,7 @@ static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu)
 
 static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)
 {
-        u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu);
+        u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
 
 #ifndef CONFIG_64BIT
         /*
@@ -9591,7 +9600,7 @@ static void cpuacct_charge(struct task_struct *tsk, u64 cputime)
         ca = task_ca(tsk);
 
         for (; ca; ca = ca->parent) {
-                u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu);
+                u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
                 *cpuusage += cputime;
         }
 }
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index ad64fcb731f2..57d4b13b631d 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -8,6 +8,7 @@
 
 #include <linux/seccomp.h>
 #include <linux/sched.h>
+#include <linux/compat.h>
 
 /* #define SECCOMP_DEBUG 1 */
 #define NR_SECCOMP_MODES 1
@@ -22,7 +23,7 @@ static int mode1_syscalls[] = {
         0, /* null terminated */
 };
 
-#ifdef TIF_32BIT
+#ifdef CONFIG_COMPAT
 static int mode1_syscalls_32[] = {
         __NR_seccomp_read_32, __NR_seccomp_write_32, __NR_seccomp_exit_32, __NR_seccomp_sigreturn_32,
         0, /* null terminated */
@@ -37,8 +38,8 @@ void __secure_computing(int this_syscall)
         switch (mode) {
         case 1:
                 syscall = mode1_syscalls;
-#ifdef TIF_32BIT
-                if (test_thread_flag(TIF_32BIT))
+#ifdef CONFIG_COMPAT
+                if (is_compat_task())
                         syscall = mode1_syscalls_32;
 #endif
                 do {
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 0cd415ee62a2..74541ca49536 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -170,7 +170,7 @@ int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
          * doesn't hit this CPU until we're ready. */
         get_cpu();
         for_each_online_cpu(i) {
-                sm_work = percpu_ptr(stop_machine_work, i);
+                sm_work = per_cpu_ptr(stop_machine_work, i);
                 INIT_WORK(sm_work, stop_cpu);
                 queue_work_on(i, stop_machine_wq, sm_work);
         }
diff --git a/kernel/sys.c b/kernel/sys.c
index f145c415bc16..37f458e6882a 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -559,7 +559,7 @@ error:
         abort_creds(new);
         return retval;
 }
-  
+
 /*
  * change the user struct in a credentials set to match the new UID
  */
@@ -571,6 +571,11 @@ static int set_user(struct cred *new)
         if (!new_user)
                 return -EAGAIN;
 
+        if (!task_can_switch_user(new_user, current)) {
+                free_uid(new_user);
+                return -EINVAL;
+        }
+
         if (atomic_read(&new_user->processes) >=
                                 current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
                         new_user != INIT_USER) {
@@ -631,10 +636,11 @@ SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
                         goto error;
         }
 
-        retval = -EAGAIN;
-        if (new->uid != old->uid && set_user(new) < 0)
-                goto error;
-
+        if (new->uid != old->uid) {
+                retval = set_user(new);
+                if (retval < 0)
+                        goto error;
+        }
         if (ruid != (uid_t) -1 ||
             (euid != (uid_t) -1 && euid != old->uid))
                 new->suid = new->euid;
@@ -680,9 +686,10 @@ SYSCALL_DEFINE1(setuid, uid_t, uid)
         retval = -EPERM;
         if (capable(CAP_SETUID)) {
                 new->suid = new->uid = uid;
-                if (uid != old->uid && set_user(new) < 0) {
-                        retval = -EAGAIN;
-                        goto error;
+                if (uid != old->uid) {
+                        retval = set_user(new);
+                        if (retval < 0)
+                                goto error;
                 }
         } else if (uid != old->uid && uid != new->suid) {
                 goto error;
@@ -734,11 +741,13 @@ SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
                         goto error;
         }
 
-        retval = -EAGAIN;
         if (ruid != (uid_t) -1) {
                 new->uid = ruid;
-                if (ruid != old->uid && set_user(new) < 0)
-                        goto error;
+                if (ruid != old->uid) {
+                        retval = set_user(new);
+                        if (retval < 0)
+                                goto error;
+                }
         }
         if (euid != (uid_t) -1)
                 new->euid = euid;
diff --git a/kernel/user.c b/kernel/user.c
index 3551ac742395..6a9b696128c8 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -362,6 +362,24 @@ static void free_user(struct user_struct *up, unsigned long flags)
 
 #endif
 
+#if defined(CONFIG_RT_GROUP_SCHED) && defined(CONFIG_USER_SCHED)
+/*
+ * We need to check if a setuid can take place. This function should be called
+ * before successfully completing the setuid.
+ */
+int task_can_switch_user(struct user_struct *up, struct task_struct *tsk)
+{
+
+        return sched_rt_can_attach(up->tg, tsk);
+
+}
+#else
+int task_can_switch_user(struct user_struct *up, struct task_struct *tsk)
+{
+        return 1;
+}
+#endif
+
 /*
  * Locate the user_struct for the passed UID.  If found, take a ref on it.  The
  * caller must undo that ref with free_uid().