Differences between version 3 and revision by previous author of MemoryMap.
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| Newer page: | version 3 | Last edited on Friday, November 28, 2003 6:02:02 pm | by JohnMcPherson | Revert |
| Older page: | version 2 | Last edited on Friday, November 28, 2003 3:16:58 pm | by AristotlePagaltzis | Revert |
@@ -6,8 +6,45 @@
| xxxxxxxx |< Process stack (grows down)
| bffff000 |< Process heap (grows up)
| 40000000 |< Libraries
| zzzzzzzz |< Unused
-| yyyyyyyy |< __.bss__ segment, uninitialised proram
data
+| yyyyyyyy |< __.bss__ segment, uninitialised program
data
| xxxxxxxx |< __.data__ segment, initialised program data
| 08048000 |< __.text__ segment, program code
| 00000000 |< Unmapped to trap NULL pointers
+
+
+!!Practical examples
+!Library-mapped memory (using ldd(1))
+ $ ldd /bin/ls
+ librt.so.1 => /lib/librt.so.1 (0x40026000)
+ libc.so.6 => /lib/libc.so.6 (0x40038000)
+ libpthread.so.0 => /lib/libpthread.so.0 (0x4016a000)
+ /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x40000000)
+
+!Program code
+ $ cat > x.c
+ #include <stdio.h>
+ int main(void) {printf("%p\n", main);return 0;}
+ $ gcc -o x x.c && ./x
+ 0x8048344
+ $
+(this is printing the address of the main function.)
+
+!Process Heap
+ $ cat > x2.c
+ #include <stdio.h>
+ int main(void) {char c;printf("%p\n", &c); return 0;}
+ $ gcc -o x2 x2.c && ./x2
+ 0xbffffab7
+
+!Process Data and bss segment
+ $ perl -e 'my $var; print \$var . "\n"'
+ SCALAR(0x814f38c)
+(note that this is the address in the [Perl] interpreter)
+
+ $ cat > x3.c
+ #include <stdio.h>
+ #include <stdlib.h>
+ int main(void) {char *p=malloc(3);printf("%p\n", p); return 0;}
+ $ gcc -o x3 x3.c && ./x3
+ 0x8049628
