Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[deliverable/linux.git] / kernel / sys.c
index 81f56445fba949790b34b7bf3f97383555134672..b95d3c72ba211a44c955ce3ae58b07fa72980cb1 100644 (file)
 #include <linux/user_namespace.h>
 #include <linux/binfmts.h>
 
+#include <linux/sched.h>
+#include <linux/rcupdate.h>
+#include <linux/uidgid.h>
+#include <linux/cred.h>
+
 #include <linux/kmsg_dump.h>
 /* Move somewhere else to avoid recompiling? */
 #include <generated/utsrelease.h>
@@ -324,7 +329,6 @@ void kernel_restart_prepare(char *cmd)
        system_state = SYSTEM_RESTART;
        usermodehelper_disable();
        device_shutdown();
-       syscore_shutdown();
 }
 
 /**
@@ -370,6 +374,7 @@ void kernel_restart(char *cmd)
 {
        kernel_restart_prepare(cmd);
        disable_nonboot_cpus();
+       syscore_shutdown();
        if (!cmd)
                printk(KERN_EMERG "Restarting system.\n");
        else
@@ -395,6 +400,7 @@ static void kernel_shutdown_prepare(enum system_states state)
 void kernel_halt(void)
 {
        kernel_shutdown_prepare(SYSTEM_HALT);
+       disable_nonboot_cpus();
        syscore_shutdown();
        printk(KERN_EMERG "System halted.\n");
        kmsg_dump(KMSG_DUMP_HALT);
@@ -1043,6 +1049,67 @@ change_okay:
        return old_fsgid;
 }
 
+/**
+ * sys_getpid - return the thread group id of the current process
+ *
+ * Note, despite the name, this returns the tgid not the pid.  The tgid and
+ * the pid are identical unless CLONE_THREAD was specified on clone() in
+ * which case the tgid is the same in all threads of the same group.
+ *
+ * This is SMP safe as current->tgid does not change.
+ */
+SYSCALL_DEFINE0(getpid)
+{
+       return task_tgid_vnr(current);
+}
+
+/* Thread ID - the internal kernel "pid" */
+SYSCALL_DEFINE0(gettid)
+{
+       return task_pid_vnr(current);
+}
+
+/*
+ * Accessing ->real_parent is not SMP-safe, it could
+ * change from under us. However, we can use a stale
+ * value of ->real_parent under rcu_read_lock(), see
+ * release_task()->call_rcu(delayed_put_task_struct).
+ */
+SYSCALL_DEFINE0(getppid)
+{
+       int pid;
+
+       rcu_read_lock();
+       pid = task_tgid_vnr(rcu_dereference(current->real_parent));
+       rcu_read_unlock();
+
+       return pid;
+}
+
+SYSCALL_DEFINE0(getuid)
+{
+       /* Only we change this so SMP safe */
+       return from_kuid_munged(current_user_ns(), current_uid());
+}
+
+SYSCALL_DEFINE0(geteuid)
+{
+       /* Only we change this so SMP safe */
+       return from_kuid_munged(current_user_ns(), current_euid());
+}
+
+SYSCALL_DEFINE0(getgid)
+{
+       /* Only we change this so SMP safe */
+       return from_kgid_munged(current_user_ns(), current_gid());
+}
+
+SYSCALL_DEFINE0(getegid)
+{
+       /* Only we change this so SMP safe */
+       return from_kgid_munged(current_user_ns(), current_egid());
+}
+
 void do_sys_times(struct tms *tms)
 {
        cputime_t tgutime, tgstime, cutime, cstime;
@@ -1784,13 +1851,26 @@ SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
        return getrusage(current, who, ru);
 }
 
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
+{
+       struct rusage r;
+
+       if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
+           who != RUSAGE_THREAD)
+               return -EINVAL;
+
+       k_getrusage(current, who, &r);
+       return put_compat_rusage(&r, ru);
+}
+#endif
+
 SYSCALL_DEFINE1(umask, int, mask)
 {
        mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
        return mask;
 }
 
-#ifdef CONFIG_CHECKPOINT_RESTORE
 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
 {
        struct fd exe;
@@ -1984,17 +2064,12 @@ out:
        return error;
 }
 
+#ifdef CONFIG_CHECKPOINT_RESTORE
 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
 {
        return put_user(me->clear_child_tid, tid_addr);
 }
-
-#else /* CONFIG_CHECKPOINT_RESTORE */
-static int prctl_set_mm(int opt, unsigned long addr,
-                       unsigned long arg4, unsigned long arg5)
-{
-       return -EINVAL;
-}
+#else
 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
 {
        return -EINVAL;
@@ -2185,9 +2260,8 @@ SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
 
 char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
 
-static int __orderly_poweroff(void)
+static int __orderly_poweroff(bool force)
 {
-       int argc;
        char **argv;
        static char *envp[] = {
                "HOME=/",
@@ -2196,20 +2270,40 @@ static int __orderly_poweroff(void)
        };
        int ret;
 
-       argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
-       if (argv == NULL) {
+       argv = argv_split(GFP_KERNEL, poweroff_cmd, NULL);
+       if (argv) {
+               ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
+               argv_free(argv);
+       } else {
                printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n",
-                      __func__, poweroff_cmd);
-               return -ENOMEM;
+                                        __func__, poweroff_cmd);
+               ret = -ENOMEM;
        }
 
-       ret = call_usermodehelper_fns(argv[0], argv, envp, UMH_WAIT_EXEC,
-                                     NULL, NULL, NULL);
-       argv_free(argv);
+       if (ret && force) {
+               printk(KERN_WARNING "Failed to start orderly shutdown: "
+                                       "forcing the issue\n");
+               /*
+                * I guess this should try to kick off some daemon to sync and
+                * poweroff asap.  Or not even bother syncing if we're doing an
+                * emergency shutdown?
+                */
+               emergency_sync();
+               kernel_power_off();
+       }
 
        return ret;
 }
 
+static bool poweroff_force;
+
+static void poweroff_work_func(struct work_struct *work)
+{
+       __orderly_poweroff(poweroff_force);
+}
+
+static DECLARE_WORK(poweroff_work, poweroff_work_func);
+
 /**
  * orderly_poweroff - Trigger an orderly system poweroff
  * @force: force poweroff if command execution fails
@@ -2219,21 +2313,154 @@ static int __orderly_poweroff(void)
  */
 int orderly_poweroff(bool force)
 {
-       int ret = __orderly_poweroff();
+       if (force) /* do not override the pending "true" */
+               poweroff_force = true;
+       schedule_work(&poweroff_work);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(orderly_poweroff);
 
-       if (ret && force) {
-               printk(KERN_WARNING "Failed to start orderly shutdown: "
-                      "forcing the issue\n");
+/**
+ * do_sysinfo - fill in sysinfo struct
+ * @info: pointer to buffer to fill
+ */
+static int do_sysinfo(struct sysinfo *info)
+{
+       unsigned long mem_total, sav_total;
+       unsigned int mem_unit, bitcount;
+       struct timespec tp;
 
-               /*
-                * I guess this should try to kick off some daemon to sync and
-                * poweroff asap.  Or not even bother syncing if we're doing an
-                * emergency shutdown?
-                */
-               emergency_sync();
-               kernel_power_off();
+       memset(info, 0, sizeof(struct sysinfo));
+
+       ktime_get_ts(&tp);
+       monotonic_to_bootbased(&tp);
+       info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
+
+       get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
+
+       info->procs = nr_threads;
+
+       si_meminfo(info);
+       si_swapinfo(info);
+
+       /*
+        * If the sum of all the available memory (i.e. ram + swap)
+        * is less than can be stored in a 32 bit unsigned long then
+        * we can be binary compatible with 2.2.x kernels.  If not,
+        * well, in that case 2.2.x was broken anyways...
+        *
+        *  -Erik Andersen <andersee@debian.org>
+        */
+
+       mem_total = info->totalram + info->totalswap;
+       if (mem_total < info->totalram || mem_total < info->totalswap)
+               goto out;
+       bitcount = 0;
+       mem_unit = info->mem_unit;
+       while (mem_unit > 1) {
+               bitcount++;
+               mem_unit >>= 1;
+               sav_total = mem_total;
+               mem_total <<= 1;
+               if (mem_total < sav_total)
+                       goto out;
        }
 
-       return ret;
+       /*
+        * If mem_total did not overflow, multiply all memory values by
+        * info->mem_unit and set it to 1.  This leaves things compatible
+        * with 2.2.x, and also retains compatibility with earlier 2.4.x
+        * kernels...
+        */
+
+       info->mem_unit = 1;
+       info->totalram <<= bitcount;
+       info->freeram <<= bitcount;
+       info->sharedram <<= bitcount;
+       info->bufferram <<= bitcount;
+       info->totalswap <<= bitcount;
+       info->freeswap <<= bitcount;
+       info->totalhigh <<= bitcount;
+       info->freehigh <<= bitcount;
+
+out:
+       return 0;
 }
-EXPORT_SYMBOL_GPL(orderly_poweroff);
+
+SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
+{
+       struct sysinfo val;
+
+       do_sysinfo(&val);
+
+       if (copy_to_user(info, &val, sizeof(struct sysinfo)))
+               return -EFAULT;
+
+       return 0;
+}
+
+#ifdef CONFIG_COMPAT
+struct compat_sysinfo {
+       s32 uptime;
+       u32 loads[3];
+       u32 totalram;
+       u32 freeram;
+       u32 sharedram;
+       u32 bufferram;
+       u32 totalswap;
+       u32 freeswap;
+       u16 procs;
+       u16 pad;
+       u32 totalhigh;
+       u32 freehigh;
+       u32 mem_unit;
+       char _f[20-2*sizeof(u32)-sizeof(int)];
+};
+
+COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
+{
+       struct sysinfo s;
+
+       do_sysinfo(&s);
+
+       /* Check to see if any memory value is too large for 32-bit and scale
+        *  down if needed
+        */
+       if ((s.totalram >> 32) || (s.totalswap >> 32)) {
+               int bitcount = 0;
+
+               while (s.mem_unit < PAGE_SIZE) {
+                       s.mem_unit <<= 1;
+                       bitcount++;
+               }
+
+               s.totalram >>= bitcount;
+               s.freeram >>= bitcount;
+               s.sharedram >>= bitcount;
+               s.bufferram >>= bitcount;
+               s.totalswap >>= bitcount;
+               s.freeswap >>= bitcount;
+               s.totalhigh >>= bitcount;
+               s.freehigh >>= bitcount;
+       }
+
+       if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) ||
+           __put_user(s.uptime, &info->uptime) ||
+           __put_user(s.loads[0], &info->loads[0]) ||
+           __put_user(s.loads[1], &info->loads[1]) ||
+           __put_user(s.loads[2], &info->loads[2]) ||
+           __put_user(s.totalram, &info->totalram) ||
+           __put_user(s.freeram, &info->freeram) ||
+           __put_user(s.sharedram, &info->sharedram) ||
+           __put_user(s.bufferram, &info->bufferram) ||
+           __put_user(s.totalswap, &info->totalswap) ||
+           __put_user(s.freeswap, &info->freeswap) ||
+           __put_user(s.procs, &info->procs) ||
+           __put_user(s.totalhigh, &info->totalhigh) ||
+           __put_user(s.freehigh, &info->freehigh) ||
+           __put_user(s.mem_unit, &info->mem_unit))
+               return -EFAULT;
+
+       return 0;
+}
+#endif /* CONFIG_COMPAT */
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