Merge remote-tracking branch 'Kernel/master'

Kernel/core/stack_check.cpp

@@ -0,0 +1,84 @@
+/*
+	This file is part of Fennix Kernel.
+
+	Fennix Kernel is free software: you can redistribute it and/or
+	modify it under the terms of the GNU General Public License as
+	published by the Free Software Foundation, either version 3 of
+	the License, or (at your option) any later version.
+
+	Fennix Kernel is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with Fennix Kernel. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <types.h>
+#include <debug.h>
+#include <rand.hpp>
+
+#include "../kernel.h"
+
+extern __noreturn void HandleStackSmashing();
+extern __noreturn void HandleBufferOverflow();
+
+/* EXTERNC */ uintptr_t __stack_chk_guard = 0;
+
+EXTERNC __no_stack_protector uintptr_t __stack_chk_guard_init(void)
+{
+	int MaxRetries = 0;
+#if UINTPTR_MAX == UINT32_MAX
+	uint32_t num;
+Retry:
+	num = Random::rand32();
+	if (num < 0x1000 && MaxRetries++ < 10)
+		goto Retry;
+	return num;
+
+#else
+	uint64_t num;
+Retry:
+	num = Random::rand64();
+	if (num < 0x100000 && MaxRetries++ < 10)
+		goto Retry;
+	return num;
+#endif
+}
+
+EXTERNC __constructor __no_stack_protector void __guard_setup(void)
+{
+	debug("__guard_setup");
+	if (__stack_chk_guard == 0)
+		__stack_chk_guard = __stack_chk_guard_init();
+	debug("Stack guard value: %ld", __stack_chk_guard);
+}
+
+EXTERNC __noreturn __no_stack_protector void __stack_chk_fail(void)
+{
+	CPU::PageTable(KernelPageTable);
+
+	void *Stack = nullptr;
+#if defined(a64)
+	asmv("movq %%rsp, %0"
+		 : "=r"(Stack));
+#elif defined(a32)
+	asmv("movl %%esp, %0"
+		 : "=r"(Stack));
+#elif defined(aa64)
+	asmv("mov %%sp, %0"
+		 : "=r"(Stack));
+#endif
+	error("Stack address: %#lx", Stack);
+
+	HandleStackSmashing();
+}
+
+// https://github.com/gcc-mirror/gcc/blob/master/libssp/ssp.c
+EXTERNC __noreturn nsa void __chk_fail(void)
+{
+	CPU::PageTable(KernelPageTable);
+
+	HandleBufferOverflow();
+}