skas-prevent-tail-call


Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
---

 linux-2.6.git-broken-paolo/arch/i386/kernel/sys_i386.c |   10 +++++++++-
 1 files changed, 9 insertions(+), 1 deletion(-)

Index: linux-2.6.git/arch/i386/kernel/sys_i386.c
===================================================================
--- linux-2.6.git.orig/arch/i386/kernel/sys_i386.c
+++ linux-2.6.git/arch/i386/kernel/sys_i386.c
@@ -70,7 +70,12 @@ asmlinkage long sys_mmap2(unsigned long 
 	unsigned long prot, unsigned long flags,
 	unsigned long fd, unsigned long pgoff)
 {
-	return do_mmap2(current->mm, addr, len, prot, flags, fd, pgoff);
+	long ret = do_mmap2(current->mm, addr, len, prot, flags, fd, pgoff);
+
+	/* A tail call would reorder parameters on the stack and they would then
+	 * be restored at the wrong places. */
+	prevent_tail_call(ret);
+	return ret;
 }
 
 /*
@@ -102,6 +107,9 @@ asmlinkage int old_mmap(struct mmap_arg_
 		goto out;
 
 	err = do_mmap2(current->mm, a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT);
+	/* A tail call would reorder parameters on the stack and they would then
+	 * be restored at the wrong places. */
+	prevent_tail_call(err);
 out:
 	return err;
 }