C Memory Distribution

First look at the test code:

#include <stdio.h>
#include <stdlib.h>

int g_val;
int g_ival = 5;

char *g_ptr;
Char *g_iptr = "Hongchunhua";

static int s_val;
static int s_ival = 5;

int Print_add (int val)
{
	int A;
	int b = 1;
	static int C;
	
	char *p = NULL;
	p = (char *) malloc (1);
	
	printf ("Address g_iptr=\t0x%x.\n", g_iptr);
	printf ("Address print_add=\t0x%x.\n", &print_add);
	printf ("Address g_ival=\t0x%x.\n", &g_ival);
	printf ("Address g_iptr=\t0x%x.\n", &g_iptr);
	printf ("Address s_ival=\t0x%x.\n", &s_ival);
	printf ("Address g_val=\t0x%x.\n", &g_val);
	printf ("Address g_ptr=\t0x%x.\n", &g_ptr);
	printf ("Address s_val=\t0x%x.\n", &s_val);
	printf ("Address c=\t0x%x.\n", &c);
	printf ("Address p=\t0x%x.\n", &p);
	printf ("Address val=\t0x%x.\n", &val);
	printf ("Address a=\t0x%x.\n", &a);
	printf ("Address b=\t0x%x.\n", &b);	
	
	Free (p);
	p = NULL;
	return 0;
}

int main ()
{return
	print_add (2);
}

Output results:

Address g_iptr= 0x8048620.
Address print_add= 0x80483e4.
Address g_ival= 0x8049834.
Address g_iptr= 0x8049838.
Address s_ival= 0x804983c.
Address g_val= 0x8049850.
Address g_ptr= 0x8049854.
Address s_val= 0x804984c.
Address c= 0x8049848.
Address p= 0xbfb5d49c.
Address val= 0xbfb5d4b0.
Address a= 0xbfb5d4a4.
Address b= 0xbfb5d4a0.

Largely from small to large output, in general we know 0-3g for user space, the remaining 1G for kernel space.

From small to large in sequence for

Code area Print_add and "Hongchunhua" this string.

Global already initialized area includes G_ival, S_ival

Global uninitialized zone, including G_val, G_ptr, C,s_val

Pile, that's p.

Stacks, including Val,a and B.

In fact, in the heap and the middle of the stack there is a region, called the mapping area, mmap use this area.