Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[safe/jmp/linux-2.6] / kernel / futex_compat.c

diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c
index 7d5e4b0..d607a5b 100644 (file)
--- a/kernel/futex_compat.c
+++ b/kernel/futex_compat.c
@@ -30,7 +30,7 @@ fetch_robust_entry(compat_uptr_t *uentry, struct robust_list __user **entry,
        return 0;
 }
 
-static void __user *futex_uaddr(struct robust_list *entry,
+static void __user *futex_uaddr(struct robust_list __user *entry,
                                compat_long_t futex_offset)
 {
        compat_uptr_t base = ptr_to_compat(entry);
@@ -54,6 +54,9 @@ void compat_exit_robust_list(struct task_struct *curr)
        compat_long_t futex_offset;
        int rc;
 
+       if (!futex_cmpxchg_enabled)
+               return;
+
        /*
         * Fetch the list head (which was registered earlier, via
         * sys_set_robust_list()):
@@ -115,6 +118,9 @@ asmlinkage long
 compat_sys_set_robust_list(struct compat_robust_list_head __user *head,
                           compat_size_t len)
 {
+       if (!futex_cmpxchg_enabled)
+               return -ENOSYS;
+
        if (unlikely(len != sizeof(*head)))
                return -EINVAL;
 
@@ -129,6 +135,10 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr,
 {
        struct compat_robust_list_head __user *head;
        unsigned long ret;
+       const struct cred *cred = current_cred(), *pcred;
+
+       if (!futex_cmpxchg_enabled)
+               return -ENOSYS;
 
        if (!pid)
                head = current->compat_robust_list;
@@ -141,8 +151,10 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr,
                if (!p)
                        goto err_unlock;
                ret = -EPERM;
-               if ((current->euid != p->euid) && (current->euid != p->uid) &&
-                               !capable(CAP_SYS_PTRACE))
+               pcred = __task_cred(p);
+               if (cred->euid != pcred->euid &&
+                   cred->euid != pcred->uid &&
+                   !capable(CAP_SYS_PTRACE))
                        goto err_unlock;
                head = p->compat_robust_list;
                read_unlock(&tasklist_lock);