matos/core/stack.c

#include "stack.h"
#include "klibc.h"
#include "types.h"

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 + sizeof(unsigned int);
    printf("[0] 0x%x\n", eip);
#endif
}