1#include <stdint.h>
2
3__attribute__((__visibility__("hidden"))) void* __fdpic_fixup(void* map, uintptr_t* a,
4                                                              uintptr_t* z) {
5    /* If map is a null pointer, the program was loaded by a
6     * non-FDPIC-aware ELF loader, and fixups are not needed,
7     * but the value for the GOT pointer is. */
8    if (!map)
9        return (void*)z[-1];
10
11    struct {
12        unsigned short version, nsegs;
13        struct fdpic_loadseg {
14            uintptr_t addr, p_vaddr, p_memsz;
15        } segs[];
16    }* lm = map;
17    int nsegs = lm->nsegs, rseg = 0, vseg = 0;
18    for (;;) {
19        while (*a - lm->segs[rseg].p_vaddr >= lm->segs[rseg].p_memsz)
20            if (++rseg == nsegs)
21                rseg = 0;
22        uintptr_t* r = (uintptr_t*)(*a + lm->segs[rseg].addr - lm->segs[rseg].p_vaddr);
23        if (++a == z)
24            return r;
25        while (*r - lm->segs[vseg].p_vaddr >= lm->segs[vseg].p_memsz)
26            if (++vseg == nsegs)
27                vseg = 0;
28        *r += lm->segs[vseg].addr - lm->segs[vseg].p_vaddr;
29    }
30}
31