sh: initial stack protector support.

This implements basic -fstack-protector support, based on the early ARM
version in c743f38013aeff58ef6252601e397b5ba281c633. The SMP case is
limited to the initial canary value, while the UP case handles per-task
granularity (limited to 32-bit sh until a new enough sh64 compiler
manifests itself).

Signed-off-by: Filippo Arcidiacono <filippo.arcidiacono@st.com>
Reviewed-by: Carmelo Amoroso <carmelo.amoroso@st.com>
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/arch/sh/kernel/process.c b/arch/sh/kernel/process.c
index 325f98b1736d..f3f03e4c785d 100644
--- a/arch/sh/kernel/process.c
+++ b/arch/sh/kernel/process.c
@@ -2,10 +2,17 @@
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/sched.h>
+#include <linux/export.h>
+#include <linux/stackprotector.h>
 
 struct kmem_cache *task_xstate_cachep = NULL;
 unsigned int xstate_size;
 
+#ifdef CONFIG_CC_STACKPROTECTOR
+unsigned long __stack_chk_guard __read_mostly;
+EXPORT_SYMBOL(__stack_chk_guard);
+#endif
+
 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 {
         *dst = *src;