stack_trace try to get function arguments

Makefile

@@ -6,7 +6,7 @@ ASFLAGS += -f elf32
 LDFLAGS += -m32 -nostdlib -static -fno-common -fno-use-cxa-atexit -fno-exceptions -fno-non-call-exceptions -fno-weak -fno-rtti -fno-stack-protector
 CFLAGS += -m32 -Wall -Wextra -Werror -ffreestanding -fno-exceptions -fno-pie -fno-stack-protector
 CXXFLAGS += -m32 -Wall -Wextra -Werror -ffreestanding -fno-exceptions -fno-rtti -fno-pie
-DEBUG_FLAGS += -g -Og -DDEBUG -fno-omit-frame-pointer
+DEBUG_FLAGS += -g -Og -DDEBUG -fno-omit-frame-pointer -fno-inline
 
 SUBDIRS := core drivers tests
 
@@ -39,7 +39,7 @@ core/irq_handler.o:core/irq_handler.c
 %.o:%.asm
 	$(AS) $(ASFLAGS) -o $@ $<
 
-self_test: CFLAGS += -DRUN_TEST
+self_test: CFLAGS += -DRUN_TEST -DDEBUG
 self_test: clean kernel
 	qemu-system-x86_64 -kernel kernel -serial stdio
 

boot.asm

@@ -55,7 +55,7 @@ _start:
 	; stack (as it grows downwards on x86 systems). This is necessarily done
 	; in assembly as languages such as C cannot function without a stack.
 	mov esp, stack_top
-	mov ebp, stack_bottom
+	mov ebp, esp
  
 	; This is a good place to initialize crucial processor state before the
 	; high-level kernel is entered. It's best to minimize the early
@@ -100,3 +100,8 @@ _start:
 .hang:	hlt
 	jmp .hang
 .end:
+
+global _stack_bottom
+_stack_bottom: dd stack_bottom
+global _stack_top
+_stack_top: dd stack_top

core/stack.c

@@ -1,28 +1,47 @@
 #include "stack.h"
+#include "types.h"
 #include "vga.h"
 
-void printStackTrace(unsigned int maxFrames){
+extern vaddr_t _stack_bottom;
+extern vaddr_t _stack_top;
+void printStackTrace(unsigned int maxFrames)
+{
 #ifdef DEBUG
 	// Now on Stack:
 	//	( potential second function argument )
 	//	first function argument (maxFrames)
 	//	return address from caller
 	//	EBP (Extended Base Pointer) of calling function
-	unsigned int * ebp = &maxFrames - 2;
+	unsigned int *ebp = __builtin_frame_address(0);
 	for (unsigned int frame = 0; frame < maxFrames; frame++) {
 		unsigned int eip = ebp[1];
 		if (eip == 0) {
 			// No caller on stack
 			break;
 		}
+		unsigned int *arguments = ebp + 2;
+		printf("[%d] 0x%x (", frame, eip);
+		int nbArg = 0;
+		do {
+			if ((_stack_bottom <= (vaddr_t)arguments) &&
+			    ((vaddr_t)arguments <= _stack_top)) {
+				printf(" 0x%x", *arguments);
+				arguments += 1;
+			} else {
+				break;
+			}
+			nbArg++;
+			if (nbArg >= 4) {
+				break;
+			}
+		} while (1);
+		printf(")\n");
 		ebp = (unsigned int *)(ebp[0]);
-		//unsigned int * arguments = &ebp[2];
-		printf("    0x%x\n", eip);
 	}
 #else
 	printf("Must be compiled with -fno-omit-frame-pointer for full stack\n");
 	unsigned int *ebp = &maxFrames - 2;
 	unsigned int eip  = ebp[1];
-	printf("Caller:    0x%x\n", eip);
+	printf("[0] 0x%x\n", eip);
 #endif
 }

tests/test.c

@@ -1,7 +1,9 @@
 #include "list.h"
+#include "klibc.h"
 #include "mem.h"
 #include "paging.h"
 #include "serial.h"
+#include "stack.h"
 #include "vga.h"
 
 void testPhymem(void)
@@ -79,13 +81,27 @@ static void testPaging(void)
 	}
 }
 
+static void test_backtrace_2(int a, int b){
+	printStackTrace(a+b);
+}
+
+static void test_backtrace_1(int a){
+	test_backtrace_2(a, 3);
+}
+
+void test_backtrace(){
+	test_backtrace_1(2);
+}
+
 void run_test(void)
 {
 	testPaging();
-	printf("Testing Serial");
+	printf("Testing Serial\n");
 	serialWrite('h');
 	serialWrite('e');
 	serialWrite('l');
 	serialWrite('l');
 	serialWrite('o');
+	printf("Testing backtrace\n");
+	test_backtrace();
 }