exec: simplify ->sighand switching

[linux-2.6] / fs / exec.c

diff --git a/fs/exec.c b/fs/exec.c
index 65825bdc4475f1706d45d46836a0f537e0b7aa71..7f325df5e0140a05444e74114aec91325ee12355 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -29,6 +29,7 @@
 #include <linux/stat.h>
 #include <linux/fcntl.h>
 #include <linux/smp_lock.h>
+#include <linux/string.h>
 #include <linux/init.h>
 #include <linux/pagemap.h>
 #include <linux/highmem.h>
@@ -81,12 +82,11 @@ int register_binfmt(struct linux_binfmt * fmt)
 
 EXPORT_SYMBOL(register_binfmt);
 
-int unregister_binfmt(struct linux_binfmt * fmt)
+void unregister_binfmt(struct linux_binfmt * fmt)
 {
        write_lock(&binfmt_lock);
        list_del(&fmt->lh);
        write_unlock(&binfmt_lock);
-       return 0;
 }
 
 EXPORT_SYMBOL(unregister_binfmt);
@@ -112,9 +112,6 @@ asmlinkage long sys_uselib(const char __user * library)
        if (error)
                goto out;
 
-       error = -EACCES;
-       if (nd.mnt->mnt_flags & MNT_NOEXEC)
-               goto exit;
        error = -EINVAL;
        if (!S_ISREG(nd.dentry->d_inode->i_mode))
                goto exit;
@@ -658,8 +655,7 @@ struct file *open_exec(const char *name)
        if (!err) {
                struct inode *inode = nd.dentry->d_inode;
                file = ERR_PTR(-EACCES);
-               if (!(nd.mnt->mnt_flags & MNT_NOEXEC) &&
-                   S_ISREG(inode->i_mode)) {
+               if (S_ISREG(inode->i_mode)) {
                        int err = vfs_permission(&nd, MAY_EXEC);
                        file = ERR_PTR(err);
                        if (!err) {
@@ -920,12 +916,7 @@ no_thread_group:
 
                write_lock_irq(&tasklist_lock);
                spin_lock(&oldsighand->siglock);
-               spin_lock_nested(&newsighand->siglock, SINGLE_DEPTH_NESTING);
-
                rcu_assign_pointer(tsk->sighand, newsighand);
-               recalc_sigpending();
-
-               spin_unlock(&newsighand->siglock);
                spin_unlock(&oldsighand->siglock);
                write_unlock_irq(&tasklist_lock);
 
@@ -935,12 +926,11 @@ no_thread_group:
        BUG_ON(!thread_group_leader(tsk));
        return 0;
 }
-       
+
 /*
  * These functions flushes out all traces of the currently running executable
  * so that a new one can be started
  */
-
 static void flush_old_files(struct files_struct * files)
 {
        long j = -1;
@@ -1515,6 +1505,14 @@ static int format_corename(char *corename, const char *pattern, long signr)
                                        goto out;
                                out_ptr += rc;
                                break;
+                       /* core limit size */
+                       case 'c':
+                               rc = snprintf(out_ptr, out_end - out_ptr,
+                                             "%lu", current->signal->rlim[RLIMIT_CORE].rlim_cur);
+                               if (rc > out_end - out_ptr)
+                                       goto out;
+                               out_ptr += rc;
+                               break;
                        default:
                                break;
                        }
@@ -1698,6 +1696,10 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
        int fsuid = current->fsuid;
        int flag = 0;
        int ispipe = 0;
+       unsigned long core_limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
+       char **helper_argv = NULL;
+       int helper_argc = 0;
+       char *delimit;
 
        audit_core_dumps(signr);
 
@@ -1731,9 +1733,6 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
         */
        clear_thread_flag(TIF_SIGPENDING);
 
-       if (current->signal->rlim[RLIMIT_CORE].rlim_cur < binfmt->min_coredump)
-               goto fail_unlock;
-
        /*
         * lock_kernel() because format_corename() is controlled by sysctl, which
         * uses lock_kernel()
@@ -1741,9 +1740,39 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
        lock_kernel();
        ispipe = format_corename(corename, core_pattern, signr);
        unlock_kernel();
+       /*
+        * Don't bother to check the RLIMIT_CORE value if core_pattern points
+        * to a pipe.  Since we're not writing directly to the filesystem
+        * RLIMIT_CORE doesn't really apply, as no actual core file will be
+        * created unless the pipe reader choses to write out the core file
+        * at which point file size limits and permissions will be imposed
+        * as it does with any other process
+        */
+       if ((!ispipe) && (core_limit < binfmt->min_coredump))
+               goto fail_unlock;
+
        if (ispipe) {
+               helper_argv = argv_split(GFP_KERNEL, corename+1, &helper_argc);
+               /* Terminate the string before the first option */
+               delimit = strchr(corename, ' ');
+               if (delimit)
+                       *delimit = '\0';
+               delimit = strrchr(helper_argv[0], '/');
+               if (delimit)
+                       delimit++;
+               else
+                       delimit = helper_argv[0];
+               if (!strcmp(delimit, current->comm)) {
+                       printk(KERN_NOTICE "Recursive core dump detected, "
+                                       "aborting\n");
+                       goto fail_unlock;
+               }
+
+               core_limit = RLIM_INFINITY;
+
                /* SIGPIPE can happen, but it's just never processed */
-               if(call_usermodehelper_pipe(corename+1, NULL, NULL, &file)) {
+               if (call_usermodehelper_pipe(corename+1, helper_argv, NULL,
+                               &file)) {
                        printk(KERN_INFO "Core dump to %s pipe failed\n",
                               corename);
                        goto fail_unlock;
@@ -1771,13 +1800,16 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
        if (!ispipe && do_truncate(file->f_path.dentry, 0, 0, file) != 0)
                goto close_fail;
 
-       retval = binfmt->core_dump(signr, regs, file);
+       retval = binfmt->core_dump(signr, regs, file, core_limit);
 
        if (retval)
                current->signal->group_exit_code |= 0x80;
 close_fail:
        filp_close(file, NULL);
 fail_unlock:
+       if (helper_argv)
+               argv_free(helper_argv);
+
        current->fsuid = fsuid;
        complete_all(&mm->core_done);
 fail: