x86: enable stack overflow detection on 64-bit

CONFIG_HW_STACK_PROTECTION is now available.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>

arch/x86/Kconfig

@@ -16,14 +16,14 @@ config ARCH
 config CPU_ATOM
 	bool # hidden
 	select CPU_HAS_FPU
-	select ARCH_HAS_STACK_PROTECTION if X86_MMU && !X86_64
+	select ARCH_HAS_STACK_PROTECTION if X86_MMU
 	select ARCH_HAS_USERSPACE if X86_MMU && !X86_64
 	help
 	  This option signifies the use of a CPU from the Atom family.
 
 config CPU_MINUTEIA
 	bool # hidden
-	select ARCH_HAS_STACK_PROTECTION if X86_MMU && !X86_64
+	select ARCH_HAS_STACK_PROTECTION if X86_MMU
 	select ARCH_HAS_USERSPACE if X86_MMU && !X86_64
 	help
 	  This option signifies the use of a CPU from the Minute IA family.
@@ -31,7 +31,7 @@ config CPU_MINUTEIA
 config CPU_APOLLO_LAKE
 	bool # hidden
 	select CPU_HAS_FPU
-	select ARCH_HAS_STACK_PROTECTION if X86_MMU && !X86_64
+	select ARCH_HAS_STACK_PROTECTION if X86_MMU
 	select ARCH_HAS_USERSPACE if X86_MMU && !X86_64
 	help
 	  This option signifies the use of a CPU from the Apollo Lake family.

arch/x86/core/Kconfig.intel64

@@ -58,4 +58,13 @@ config ISR_SUBSTACK_SIZE
 	  CONFIG_ISR_SUBSTACK_SIZE * CONFIG_ISR_DEPTH must be equal to
 	  CONFIG_ISR_STACK_SIZE.
 
+config X86_STACK_PROTECTION
+	bool
+	default y if HW_STACK_PROTECTION
+	select THREAD_STACK_INFO
+	help
+	  This option leverages the MMU to cause a system fatal error if the
+	  bounds of the current process stack are overflowed. This is done
+	  by preceding all stack areas with a 4K guard page.
+
 endif # X86_64

arch/x86/core/intel64/fatal.c

@@ -15,5 +15,11 @@ void z_x86_exception(const z_arch_esf_t *esf)
 	LOG_ERR("** CPU Exception %ld (code %ld/0x%lx) **",
 		esf->vector, esf->code, esf->code);
 
+#ifdef CONFIG_THREAD_STACK_INFO
+	if (z_x86_check_stack_bounds(esf->rsp, 0, esf->cs)) {
+		z_x86_fatal_error(K_ERR_STACK_CHK_FAIL, esf);
+	}
+#endif
+
 	z_x86_fatal_error(K_ERR_CPU_EXCEPTION, esf);
 }

arch/x86/core/intel64/thread.c

@@ -15,10 +15,22 @@ void z_arch_new_thread(struct k_thread *thread, k_thread_stack_t *stack,
 		       void *parameter1, void *parameter2, void *parameter3,
 		       int priority, unsigned int options)
 {
+#if defined(CONFIG_X86_USERSPACE) || defined(CONFIG_X86_STACK_PROTECTION)
+	struct z_x86_thread_stack_header *header =
+		(struct z_x86_thread_stack_header *)stack;
+#endif
+
 	Z_ASSERT_VALID_PRIO(priority, entry);
 	z_new_thread_init(thread, Z_THREAD_STACK_BUFFER(stack),
 			  stack_size, priority, options);
 
+#if CONFIG_X86_STACK_PROTECTION
+	/* Set guard area to read-only to catch stack overflows */
+	z_x86_mmu_set_flags(&z_x86_kernel_ptables, &header->guard_page,
+			    MMU_PAGE_SIZE, MMU_ENTRY_READ, Z_X86_MMU_RW,
+			    true);
+#endif
+
 	thread->callee_saved.rsp = (long) Z_THREAD_STACK_BUFFER(stack);
 	thread->callee_saved.rsp += (stack_size - 8); /* fake RIP for ABI */
 	thread->callee_saved.rip = (long) z_thread_entry;