Re: [PATCH 1/2] powerpc: initial stack protector (-fstack-protector) support

From: Segher Boessenkool
Date: Mon Sep 17 2018 - 13:13:28 EST


Hi!

On Mon, Sep 17, 2018 at 12:15:05PM +0000, Christophe Leroy wrote:
> Now, GCC offers the possibility to manually set the
> stack-protector mode (global or tls) regardless of libc support.

Yup :-)

> This time, the patch selects HAVE_STACKPROTECTOR only if
> -mstack-protector-guard=global is supported by GCC.

"global" is weaker than "tls" (it is easier to read the cookie in an
exploit). It is better to use tls if you can.


Segher