Always lookup priv_root on reiserfs mount and keep it

[safe/jmp/linux-2.6] / fs / exec.c

diff --git a/fs/exec.c b/fs/exec.c
index 614991b..639177b 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -53,6 +53,7 @@
 #include <linux/tracehook.h>
 #include <linux/kmod.h>
 #include <linux/fsnotify.h>
+#include <linux/fs_struct.h>
 
 #include <asm/uaccess.h>
 #include <asm/mmu_context.h>
@@ -68,17 +69,18 @@ int suid_dumpable = 0;
 static LIST_HEAD(formats);
 static DEFINE_RWLOCK(binfmt_lock);
 
-int register_binfmt(struct linux_binfmt * fmt)
+int __register_binfmt(struct linux_binfmt * fmt, int insert)
 {
        if (!fmt)
                return -EINVAL;
        write_lock(&binfmt_lock);
-       list_add(&fmt->lh, &formats);
+       insert ? list_add(&fmt->lh, &formats) :
+                list_add_tail(&fmt->lh, &formats);
        write_unlock(&binfmt_lock);
        return 0;       
 }
 
-EXPORT_SYMBOL(register_binfmt);
+EXPORT_SYMBOL(__register_binfmt);
 
 void unregister_binfmt(struct linux_binfmt * fmt)
 {
@@ -1059,7 +1061,6 @@ EXPORT_SYMBOL(install_exec_creds);
 int check_unsafe_exec(struct linux_binprm *bprm)
 {
        struct task_struct *p = current, *t;
-       unsigned long flags;
        unsigned n_fs;
        int res = 0;
 
@@ -1067,21 +1068,22 @@ int check_unsafe_exec(struct linux_binprm *bprm)
 
        n_fs = 1;
        write_lock(&p->fs->lock);
-       lock_task_sighand(p, &flags);
+       rcu_read_lock();
        for (t = next_thread(p); t != p; t = next_thread(t)) {
                if (t->fs == p->fs)
                        n_fs++;
        }
+       rcu_read_unlock();
 
        if (p->fs->users > n_fs) {
                bprm->unsafe |= LSM_UNSAFE_SHARE;
        } else {
-               if (p->fs->in_exec)
-                       res = -EAGAIN;
-               p->fs->in_exec = 1;
+               res = -EAGAIN;
+               if (!p->fs->in_exec) {
+                       p->fs->in_exec = 1;
+                       res = 1;
+               }
        }
-
-       unlock_task_sighand(p, &flags);
        write_unlock(&p->fs->lock);
 
        return res;
@@ -1283,6 +1285,7 @@ int do_execve(char * filename,
        struct linux_binprm *bprm;
        struct file *file;
        struct files_struct *displaced;
+       bool clear_in_exec;
        int retval;
 
        retval = unshare_files(&displaced);
@@ -1305,8 +1308,9 @@ int do_execve(char * filename,
                goto out_unlock;
 
        retval = check_unsafe_exec(bprm);
-       if (retval)
+       if (retval < 0)
                goto out_unlock;
+       clear_in_exec = retval;
 
        file = open_exec(filename);
        retval = PTR_ERR(file);
@@ -1354,9 +1358,7 @@ int do_execve(char * filename,
                goto out;
 
        /* execve succeeded */
-       write_lock(&current->fs->lock);
        current->fs->in_exec = 0;
-       write_unlock(&current->fs->lock);
        current->in_execve = 0;
        mutex_unlock(&current->cred_exec_mutex);
        acct_update_integrals(current);
@@ -1376,9 +1378,8 @@ out_file:
        }
 
 out_unmark:
-       write_lock(&current->fs->lock);
-       current->fs->in_exec = 0;
-       write_unlock(&current->fs->lock);
+       if (clear_in_exec)
+               current->fs->in_exec = 0;
 
 out_unlock:
        current->in_execve = 0;