Added kernel patch for /proc/self/exe to examples

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/examples/linux-2.6.30_proc_self_exe.patch b/examples/linux-2.6.30_proc_self_exe.patch
new file mode 100644 (file)
index 0000000..a36581b
--- /dev/null
+++ b/examples/linux-2.6.30_proc_self_exe.patch
@@ -0,0 +1,34 @@
+This patch makes /proc/self/exe executable even if proc
+is not mounted. It is especially useful on NOMMU arches.
+
+diff -urp ../linux-2.6.30.org/fs/exec.c linux-2.6.30/fs/exec.c
+--- ../linux-2.6.30.org/fs/exec.c      2009-06-10 05:05:27.000000000 +0200
++++ linux-2.6.30/fs/exec.c     2009-06-25 00:20:13.000000000 +0200
+@@ -652,9 +652,25 @@ struct file *open_exec(const char *name)
+       file = do_filp_open(AT_FDCWD, name,
+                               O_LARGEFILE | O_RDONLY | FMODE_EXEC, 0,
+                               MAY_EXEC | MAY_OPEN);
+-      if (IS_ERR(file))
+-              goto out;
++      if (IS_ERR(file)) {
++              if ((PTR_ERR(file) == -ENOENT || PTR_ERR(file) == -EACCES)
++               && strcmp(name, "/proc/self/exe") == 0
++              ) {
++                      struct file *sv = file;
++                      struct mm_struct *mm;
+ 
++                      mm = get_task_mm(current);
++                      if (!mm)
++                              goto out;
++                      file = get_mm_exe_file(mm);
++                      mmput(mm);
++                      if (file)
++                              goto ok;
++                      file = sv;
++              }
++              goto out;
++      }
++ok:
+       err = -EACCES;
+       if (!S_ISREG(file->f_path.dentry->d_inode->i_mode))
+               goto exit;