niansa-misc/musl
1
0
Fork 0
mirror of git://git.musl-libc.org/musl synced 2025-03-06 20:48:29 +01:00
Code Issues Projects Releases Packages Wiki Activity

provide arch-generic fdpic self-relocation code for crt1 to use

Browse source 
this file is intended to be included by crt_arch.h on fdpic-based
targets and needs to be called from the entry point asm.
This commit is contained in:
Rich Felker 2015-09-12 03:10:44 +00:00
parent 234c58467c
commit 6d03c4ee58
1 changed files with 28 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

28
src/internal/fdpic_crt.h Normal file
View file

@ -0,0 +1,28 @@
#include <stdint.h>
__attribute__((__visibility__("hidden")))
void *__fdpic_fixup(void *map, uintptr_t *a, uintptr_t *z)
{
/* If map is a null pointer, the program was loaded by a
* non-FDPIC-aware ELF loader, and fixups are not needed,
* but the value for the GOT pointer is. */
if (!map) return (void *)z[-1];
struct {
unsigned short version, nsegs;
struct fdpic_loadseg {
uintptr_t addr, p_vaddr, p_memsz;
} segs[];
} *lm = map;
int nsegs = lm->nsegs, rseg = 0, vseg = 0;
for (;;) {
while (*a-lm->segs[rseg].p_vaddr >= lm->segs[rseg].p_memsz)
if (++rseg == nsegs) rseg = 0;
uintptr_t *r = (uintptr_t *)
(*a + lm->segs[rseg].addr - lm->segs[rseg].p_vaddr);
if (++a == z) return r;
while (*r-lm->segs[vseg].p_vaddr >= lm->segs[vseg].p_memsz)
if (++vseg == nsegs) vseg = 0;
*r += lm->segs[vseg].addr - lm->segs[vseg].p_vaddr;
}
}