5 files changed, 68 insertions, 24 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 53d86b4b0ce0..2727f9238359 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -782,7 +782,14 @@ static int parse_cgroupfs_options(char *data,
                 if (!*token)
                         return -EINVAL;
                 if (!strcmp(token, "all")) {
-                        opts->subsys_bits = (1 << CGROUP_SUBSYS_COUNT) - 1;
+                        /* Add all non-disabled subsystems */
+                        int i;
+                        opts->subsys_bits = 0;
+                        for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
+                                struct cgroup_subsys *ss = subsys[i];
+                                if (!ss->disabled)
+                                        opts->subsys_bits |= 1ul << i;
+                        }
                 } else if (!strcmp(token, "noprefix")) {
                         set_bit(ROOT_NOPREFIX, &opts->flags);
                 } else if (!strncmp(token, "release_agent=", 14)) {
@@ -800,7 +807,8 @@ static int parse_cgroupfs_options(char *data,
                         for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
                                 ss = subsys[i];
                                 if (!strcmp(token, ss->name)) {
-                                        set_bit(i, &opts->subsys_bits);
+                                        if (!ss->disabled)
+                                                set_bit(i, &opts->subsys_bits);
                                         break;
                                 }
                         }
@@ -2561,6 +2569,7 @@ static int proc_cgroup_show(struct seq_file *m, void *v)
                 /* Skip this hierarchy if it has no active subsystems */
                 if (!root->actual_subsys_bits)
                         continue;
+                seq_printf(m, "%lu:", root->subsys_bits);
                 for_each_subsys(root, ss)
                         seq_printf(m, "%s%s", count++ ? "," : "", ss->name);
                 seq_putc(m, ':');
@@ -2600,13 +2609,13 @@ static int proc_cgroupstats_show(struct seq_file *m, void *v)
 {
         int i;
 
-        seq_puts(m, "#subsys_name\thierarchy\tnum_cgroups\n");
+        seq_puts(m, "#subsys_name\thierarchy\tnum_cgroups\tenabled\n");
         mutex_lock(&cgroup_mutex);
         for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
                 struct cgroup_subsys *ss = subsys[i];
-                seq_printf(m, "%s\t%lu\t%d\n",
+                seq_printf(m, "%s\t%lu\t%d\t%d\n",
                            ss->name, ss->root->subsys_bits,
-                           ss->root->number_of_cgroups);
+                           ss->root->number_of_cgroups, !ss->disabled);
         }
         mutex_unlock(&cgroup_mutex);
         return 0;
@@ -3010,3 +3019,27 @@ static void cgroup_release_agent(struct work_struct *work)
         spin_unlock(&release_list_lock);
         mutex_unlock(&cgroup_mutex);
 }
+
+static int __init cgroup_disable(char *str)
+{
+        int i;
+        char *token;
+
+        while ((token = strsep(&str, ",")) != NULL) {
+                if (!*token)
+                        continue;
+
+                for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
+                        struct cgroup_subsys *ss = subsys[i];
+
+                        if (!strcmp(token, ss->name)) {
+                                ss->disabled = 1;
+                                printk(KERN_INFO "Disabling %s control group"
+                                        " subsystem\n", ss->name);
+                                break;
+                        }
+                }
+        }
+        return 1;
+}
+__setup("cgroup_disable=", cgroup_disable);
diff --git a/kernel/exit.c b/kernel/exit.c
index 53872bf993fa..073005b1cfb2 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1608,7 +1608,7 @@ asmlinkage long sys_waitid(int which, pid_t upid,
         put_pid(pid);
 
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(5, ret, which, upid, infop, options, ru);
         return ret;
 }
 
@@ -1640,7 +1640,7 @@ asmlinkage long sys_wait4(pid_t upid, int __user *stat_addr,
         put_pid(pid);
 
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(4, ret, upid, stat_addr, options, ru);
         return ret;
 }
 
diff --git a/kernel/printk.c b/kernel/printk.c
index c46a20a19a15..bdd4ea8c3f2b 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -643,8 +643,21 @@ static int acquire_console_semaphore_for_printk(unsigned int cpu)
 {
         int retval = 0;
 
-        if (can_use_console(cpu))
-                retval = !try_acquire_console_sem();
+        if (!try_acquire_console_sem()) {
+                retval = 1;
+
+                /*
+                 * If we can't use the console, we need to release
+                 * the console semaphore by hand to avoid flushing
+                 * the buffer. We need to hold the console semaphore
+                 * in order to do this test safely.
+                 */
+                if (!can_use_console(cpu)) {
+                        console_locked = 0;
+                        up(&console_sem);
+                        retval = 0;
+                }
+        }
         printk_cpu = UINT_MAX;
         spin_unlock(&logbuf_lock);
         return retval;
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 86a93376282c..0080968d3e4a 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -510,10 +510,8 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
 
         if (!initial) {
                 /* sleeps upto a single latency don't count. */
-                if (sched_feat(NEW_FAIR_SLEEPERS)) {
-                        vruntime -= calc_delta_fair(sysctl_sched_latency,
-                                                    &cfs_rq->load);
-                }
+                if (sched_feat(NEW_FAIR_SLEEPERS))
+                        vruntime -= sysctl_sched_latency;
 
                 /* ensure we never gain time by being placed backwards. */
                 vruntime = max_vruntime(se->vruntime, vruntime);
diff --git a/kernel/uid16.c b/kernel/uid16.c
index dd308ba4e03b..3e41c1673e2f 100644
--- a/kernel/uid16.c
+++ b/kernel/uid16.c
@@ -21,7 +21,7 @@ asmlinkage long sys_chown16(const char __user * filename, old_uid_t user, old_gi
 {
         long ret = sys_chown(filename, low2highuid(user), low2highgid(group));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(3, ret, filename, user, group);
         return ret;
 }
 
@@ -29,7 +29,7 @@ asmlinkage long sys_lchown16(const char __user * filename, old_uid_t user, old_g
 {
         long ret = sys_lchown(filename, low2highuid(user), low2highgid(group));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(3, ret, filename, user, group);
         return ret;
 }
 
@@ -37,7 +37,7 @@ asmlinkage long sys_fchown16(unsigned int fd, old_uid_t user, old_gid_t group)
 {
         long ret = sys_fchown(fd, low2highuid(user), low2highgid(group));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(3, ret, fd, user, group);
         return ret;
 }
 
@@ -45,7 +45,7 @@ asmlinkage long sys_setregid16(old_gid_t rgid, old_gid_t egid)
 {
         long ret = sys_setregid(low2highgid(rgid), low2highgid(egid));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(2, ret, rgid, egid);
         return ret;
 }
 
@@ -53,7 +53,7 @@ asmlinkage long sys_setgid16(old_gid_t gid)
 {
         long ret = sys_setgid(low2highgid(gid));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(1, ret, gid);
         return ret;
 }
 
@@ -61,7 +61,7 @@ asmlinkage long sys_setreuid16(old_uid_t ruid, old_uid_t euid)
 {
         long ret = sys_setreuid(low2highuid(ruid), low2highuid(euid));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(2, ret, ruid, euid);
         return ret;
 }
 
@@ -69,7 +69,7 @@ asmlinkage long sys_setuid16(old_uid_t uid)
 {
         long ret = sys_setuid(low2highuid(uid));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(1, ret, uid);
         return ret;
 }
 
@@ -78,7 +78,7 @@ asmlinkage long sys_setresuid16(old_uid_t ruid, old_uid_t euid, old_uid_t suid)
         long ret = sys_setresuid(low2highuid(ruid), low2highuid(euid),
                                  low2highuid(suid));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(3, ret, ruid, euid, suid);
         return ret;
 }
 
@@ -98,7 +98,7 @@ asmlinkage long sys_setresgid16(old_gid_t rgid, old_gid_t egid, old_gid_t sgid)
         long ret = sys_setresgid(low2highgid(rgid), low2highgid(egid),
                                  low2highgid(sgid));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(3, ret, rgid, egid, sgid);
         return ret;
 }
 
@@ -117,7 +117,7 @@ asmlinkage long sys_setfsuid16(old_uid_t uid)
 {
         long ret = sys_setfsuid(low2highuid(uid));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(1, ret, uid);
         return ret;
 }
 
@@ -125,7 +125,7 @@ asmlinkage long sys_setfsgid16(old_gid_t gid)
 {
         long ret = sys_setfsgid(low2highgid(gid));
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(1, ret, gid);
         return ret;
 }