From 910b5116f48294de9ccff56ba34688330f619d5d Mon Sep 17 00:00:00 2001
From: "Justin C. Miller" <justin@devjustinian.com>
Date: Tue, 16 Apr 2019 23:39:52 -0700
Subject: [PATCH] Fix stack overruns

---
 src/kernel/boot.s                             |  2 +-
 src/kernel/interrupts.cpp                     | 32 ++++++++++---------
 src/libraries/kutil/include/kutil/logger.h    |  2 +-
 .../kutil/include/kutil/slab_allocator.h      |  2 +-
 src/libraries/kutil/logger.cpp                |  4 +--
 5 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/src/kernel/boot.s b/src/kernel/boot.s
index 7b9ae17..2fbc4da 100644
--- a/src/kernel/boot.s
+++ b/src/kernel/boot.s
@@ -48,7 +48,7 @@ interrupts_disable:
 section .bss
 align 0x100
 idle_stack_begin:
-	resb 0x1000 ; 4KiB stack space
+	resb 0x4000 ; 16KiB stack space
 
 global idle_stack_end
 idle_stack_end:
diff --git a/src/kernel/interrupts.cpp b/src/kernel/interrupts.cpp
index 3677bb8..c71225a 100644
--- a/src/kernel/interrupts.cpp
+++ b/src/kernel/interrupts.cpp
@@ -184,22 +184,24 @@ isr_handler(cpu_state *regs)
 			uintptr_t cr2 = 0;
 			__asm__ __volatile__ ("mov %%cr2, %0" : "=r"(cr2));
 
-			if (!page_manager::get()->fault_handler(cr2)) {
-				cons->set_color(11);
-				cons->puts("\nPage Fault:\n");
-				cons->set_color();
+			if ((regs->errorcode & 0x9) == 0 &&
+				page_manager::get()->fault_handler(cr2))
+				break;
 
-				cons->puts("       flags:");
-				if (regs->errorcode & 0x01) cons->puts(" present");
-				if (regs->errorcode & 0x02) cons->puts(" write");
-				if (regs->errorcode & 0x04) cons->puts(" user");
-				if (regs->errorcode & 0x08) cons->puts(" reserved");
-				if (regs->errorcode & 0x10) cons->puts(" ip");
-				cons->puts("\n");
-				print_regs(*regs);
-				print_stacktrace(2);
-				_halt();
-			}
+			cons->set_color(11);
+			cons->puts("\nPage Fault:\n");
+			cons->set_color();
+
+			cons->puts("       flags:");
+			if (regs->errorcode & 0x01) cons->puts(" present");
+			if (regs->errorcode & 0x02) cons->puts(" write");
+			if (regs->errorcode & 0x04) cons->puts(" user");
+			if (regs->errorcode & 0x08) cons->puts(" reserved");
+			if (regs->errorcode & 0x10) cons->puts(" ip");
+			cons->puts("\n");
+			print_regs(*regs);
+			print_stacktrace(2);
+			_halt();
 		}
 		break;
 
diff --git a/src/libraries/kutil/include/kutil/logger.h b/src/libraries/kutil/include/kutil/logger.h
index 56baee6..bf54e04 100644
--- a/src/libraries/kutil/include/kutil/logger.h
+++ b/src/libraries/kutil/include/kutil/logger.h
@@ -110,7 +110,7 @@ void fatal(area_t area, const char *fmt, ...);
 } // namespace log
 
 namespace logs {
-#define LOG(name, lvl) extern log::area_t name;
+#define LOG(name, lvl) extern const log::area_t name;
 #include "log_areas.inc"
 #undef LOG
 } // namespace logs
diff --git a/src/libraries/kutil/include/kutil/slab_allocator.h b/src/libraries/kutil/include/kutil/slab_allocator.h
index 59f5ee0..df25306 100644
--- a/src/libraries/kutil/include/kutil/slab_allocator.h
+++ b/src/libraries/kutil/include/kutil/slab_allocator.h
@@ -29,7 +29,7 @@ public:
 	/// \returns  An allocated element
 	inline item_type * pop()
 	{
-		if (this->empty()) allocate();
+		if (this->empty()) this->allocate();
 		kassert(!this->empty(), "Slab allocator is empty after allocate()");
 		item_type *item = this->pop_front();
 		kutil::memset(item, 0, sizeof(item_type));
diff --git a/src/libraries/kutil/logger.cpp b/src/libraries/kutil/logger.cpp
index aa2a968..428c3fd 100644
--- a/src/libraries/kutil/logger.cpp
+++ b/src/libraries/kutil/logger.cpp
@@ -7,7 +7,7 @@
 namespace kutil {
 namespace logs {
 #define LOG(name, lvl) \
-	log::area_t name = #name ## _h; \
+	const log::area_t name = #name ## _h; \
 	const char * name ## _name = #name;
 #include "log_areas.inc"
 #undef LOG
@@ -19,7 +19,7 @@ using kutil::memset;
 using kutil::memcpy;
 
 logger *logger::s_log = nullptr;
-const char *logger::s_level_names[] = {"", "debug", " info", " warn", "error", "fatal"};
+const char *logger::s_level_names[] = {"", "debug", "info", "warn", "error", "fatal"};
 
 logger::logger() :
 	m_buffer(nullptr, 0),