Re: [PATCH][RESEND] PIE randomization

[Jakub Jelinek <jakub@redhat.com>]

On Mon, Jul 09, 2007 at 11:58:07PM +0200, Jiri Kosina wrote:
> On Mon, 9 Jul 2007, Jiri Kosina wrote:
> > [ ... ]
> > > -			if (!BAD_ADDR(elf_entry)) {
> > > +			if (!IS_ERR((void *)elf_entry)) {
> > I agree that this is better solution. Andrew, this Jakub's patch should 
> > replace the pie-randomization-fix-bad_addr-macro.patch if possible. You 
> > can add 
> 
> as this raced :) with Andrew who already folded the 
> pie-randomization-fix-bad_addr-macro.patch into pie-randomization.patch, 
> do you think you could rebase this change against the current state of -mm 
> and resend it? Thanks,

Here it is:

Restore BAD_ADDR check strictness, use IS_ERR in the only place where
the stricter BAD_ADDR can't work, as the value is a load bias rather
than userland address.

Signed-off-by: Jakub Jelinek <jakub@redhat.com>

--- linux/fs/binfmt_elf.c	2007-07-10 11:39:29.000000000 +0200
+++ linux/fs/binfmt_elf.c	2007-07-10 11:41:03.000000000 +0200
@@ -80,7 +80,7 @@ static struct linux_binfmt elf_format = 
 		.hasvdso	= 1
 };
 
-#define BAD_ADDR(x) IS_ERR_VALUE(x)
+#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
 
 static int set_brk(unsigned long start, unsigned long end)
 {
@@ -1005,7 +1005,7 @@ static int load_elf_binary(struct linux_
 						    interpreter,
 						    &interp_map_addr,
 						    load_bias);
-			if (!BAD_ADDR(elf_entry)) {
+			if (!IS_ERR((void *)elf_entry)) {
 				/*
 				 * load_elf_interp() returns relocation
 				 * adjustment


	Jakub