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

From: Segher Boessenkool <[email-masked]>
Date: Mon, 17 Sep 2018 11:46:13 -0500

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