test-getbp.c

#include <strings.h>
#include <stdio.h>
#include <execinfo.h>

struct stack_frame {
  struct stack_frame *prev;
	void *return_addr;
} __attribute__((packed));
typedef struct stack_frame stack_frame;

__attribute__((noinline, noclone))
void backtrace_from_fp(void **buf, int size)
{
	int i;
	stack_frame *fp;

	__asm__("movl %%ebp, %[fp]" :  /* output */ [fp] "=r" (fp));

	for(i = 0; i < size && fp != NULL; fp = fp->prev, i++)
		buf[i] = fp->return_addr;
}

#define ARRAY_SIZE(a) (sizeof(a)/sizeof((a)[0]))
enum {
	N = 100,
};
void *trace_buf[N];

__attribute__((optimize("no-omit-frame-pointer", "O0"), noinline, noclone))
void h(void)
{
	int i;
	bzero(trace_buf, ARRAY_SIZE(trace_buf));
	backtrace_from_fp(trace_buf, ARRAY_SIZE(trace_buf));
	printf("backtrace_from_fp:\n");
	/* skipping trace_buf[0] since we're calling my_backtrace() and backtrace()
	 * from different places within this function */
	for (i = 1; i < ARRAY_SIZE(trace_buf); i++) {
		if (!trace_buf[i])
			break;
		printf("%p\n", trace_buf[i]);
	}
	printf("\nbacktrace:\n");
	backtrace(trace_buf, ARRAY_SIZE(trace_buf));
	for (i = 1; i < ARRAY_SIZE(trace_buf); i++) {
		if (!trace_buf[i])
			break;
		printf("%p\n", trace_buf[i]);
	}
}

__attribute__((optimize("no-omit-frame-pointer", "O0"), noinline, noclone))
void f(void)
{
	h();
}

__attribute__((optimize("no-omit-frame-pointer", "O0"), noinline, noclone)
void g(void)
{
	f();
}

int main()
{
	g();
	return 0;
}