matos/core/stack.c

#include "stack.h"
#include "types.h"
#include "vga.h"

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
	//
	// retrace function from address could done by optaining function address with gdb or
	// objdump -S kernel
	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]);
	}
#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("[0] 0x%x\n", eip);
#endif
}