How to find text segment range in iOS - ios

Question

How can I find the text segment (AKA code segment) range in iOS? Meaning, what is the start address and the end address of the text segment?
I found this interesting post but it works for me on Android but not on iOS.

Answer 1

After some digging and expert help (thanks Moshe Kravchik) I got to the desired solution - getting the text segment range by parsing the mach header and retrieving the load commands, segments and sections.
#include <mach-o/dyld.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dlfcn.h>
#import <Foundation/Foundation.h>
#define PRINT_STR "Found __text Section of %s, addr 0x%x, size %u, offset 0x%x, calc address 0x%x"
#define LC_SEGMENT_NATIVE LC_SEGMENT
#define segment_command_native segment_command
#define section_native section
struct libRange
{
uint32_t start;
uint32_t end;
};
void getTextSegmentAddr(struct libRange *txtSegRange)
{
if (txtSegRange==NULL)
return;
txtSegRange->start=0;
const struct mach_header *mach_hdr;
mach_hdr = _dyld_get_image_header(0);
const struct load_command *cmds = (const struct load_command *)(mach_hdr + 1);
uint32_t cmdsleft;
const struct load_command *lc;
for(lc = cmds, cmdsleft = mach_hdr->ncmds; cmdsleft-- && (0 == txtSegRange->start);) {
if(lc->cmd == LC_SEGMENT_NATIVE) {
const struct segment_command_native *sc = (void *) lc;
const struct section_native *sect = (void *) (sc + 1);
for(uint32_t sect_idx = 0; sect_idx < sc->nsects; sect_idx++) {
if(!strcmp("__TEXT", sect->segname) && !strcmp("__text", sect->sectname)) {
uint32_t memAddr = (sc->vmaddr + _dyld_get_image_vmaddr_slide(0) + sect->offset - sc->fileoff);
NSLog(#PRINT_STR,_dyld_get_image_name(0), sect->addr, sect->size, sect->offset, memAddr);
txtSegRange->start = memAddr;
txtSegRange->end = memAddr + sect->size;
break;
}
sect++;
}
}
lc = (void *) ((char *) lc + lc->cmdsize);
}
}
int main()
{
struct libRange txtSegRange;
getTextSegmentAddr(&txtSegRange);
return 0;
}