From 6ec747105bfa8d52aca77bc577268f1944b19585 Mon Sep 17 00:00:00 2001
From: Michal Idziorek <m.i@gmx.at>
Date: Tue, 25 Nov 2014 12:22:35 +0100
Subject: started adding stack shmashing protection

---
 Makefile            |  3 ++-
 kernel/kernel.c     | 21 +++++++++++++++++++++
 userspace/Makefile  |  1 +
 userspace/sys/sys.c | 24 ++++++++++++++++++++++++
 4 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 3469bce..6806c1b 100644
--- a/Makefile
+++ b/Makefile
@@ -28,7 +28,8 @@ CC=i686-foolos-gcc
 
 ############ compiler flags ############
 CFLAGS=
-CFLAGS=-w
+CFLAGS+=-fstack-protector-all
+CFLAGS+=-w
 CFLAGS+=-ffreestanding 
 CFLATS+=-Wall
 CFLAGS+=-Wextra
diff --git a/kernel/kernel.c b/kernel/kernel.c
index 59ad130..77970c3 100644
--- a/kernel/kernel.c
+++ b/kernel/kernel.c
@@ -31,6 +31,27 @@
 
 #include "task.h"
 
+#include <stdint.h>
+#include <stdlib.h>
+
+
+// CODE FOR Stack Smashing Protector, TODO: MOVE / and do not duplicate
+// with sys.c
+// http://wiki.osdev.org/Stack_Smashing_Protector
+ 
+#if UINT32_MAX == UINTPTR_MAX
+#define STACK_CHK_GUARD 0xe2dee396
+#else
+#define STACK_CHK_GUARD 0x595e9fbd94fda766
+#endif
+ 
+uintptr_t __stack_chk_guard = STACK_CHK_GUARD;
+ 
+__attribute__((noreturn))
+void __stack_chk_fail(void)
+{
+	panic(FOOLOS_MODULE_NAME,"Stack smashing detected");
+}
 
 // mp informs us if this if this is the main processor
 void kernel_main(uint32_t initial_stack, int mp)
diff --git a/userspace/Makefile b/userspace/Makefile
index 63310bf..6c6d711 100644
--- a/userspace/Makefile
+++ b/userspace/Makefile
@@ -1,6 +1,7 @@
 CC=i686-foolos-gcc
 
 CFLAGS=
+#CFLAGS+=-fstack-protector-all
 CFLAGS+=-I..
 CFLAGS+=-w
 CFLAGS+=-std=gnu11
diff --git a/userspace/sys/sys.c b/userspace/sys/sys.c
index ef0d1df..1ab3579 100644
--- a/userspace/sys/sys.c
+++ b/userspace/sys/sys.c
@@ -3,6 +3,30 @@
 #include <sys/stat.h>
 
 
+// CODE FOR Stack Smashing Protector, TODO: MOVE / and do not duplicate
+// with kernel.c
+// http://wiki.osdev.org/Stack_Smashing_Protector
+#include <stdint.h>
+#include <stdlib.h>
+ 
+#if UINT32_MAX == UINTPTR_MAX
+#define STACK_CHK_GUARD 0xe2dee396
+#else
+#define STACK_CHK_GUARD 0x595e9fbd94fda766
+#endif
+ 
+uintptr_t __stack_chk_guard = STACK_CHK_GUARD;
+ 
+__attribute__((noreturn))
+void __stack_chk_fail(void)
+{
+    write(1,"stack smashing!\n",16);
+    exit(99);
+}
+
+
+///////////////////
+
 // required by binutils!
 
 long sysconf(int name)
-- 
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