| #include <stddef.h> |
| #include "dynlink.h" |
| |
| #ifdef SHARED |
| |
| #ifndef START |
| #define START "_dlstart" |
| #endif |
| |
| #include "crt_arch.h" |
| |
| #ifndef GETFUNCSYM |
| #define GETFUNCSYM(fp, sym, got) do { \ |
| __attribute__((__visibility__("hidden"))) void sym(); \ |
| static void (*static_func_ptr)() = sym; \ |
| __asm__ __volatile__ ( "" : "+m"(static_func_ptr) : : "memory"); \ |
| *(fp) = static_func_ptr; } while(0) |
| #endif |
| |
| __attribute__((__visibility__("hidden"))) |
| void _dlstart_c(size_t *sp, size_t *dynv) |
| { |
| size_t i, aux[AUX_CNT], dyn[DYN_CNT]; |
| size_t *rel, rel_size, base; |
| |
| int argc = *sp; |
| char **argv = (void *)(sp+1); |
| |
| for (i=argc+1; argv[i]; i++); |
| size_t *auxv = (void *)(argv+i+1); |
| |
| for (i=0; i<AUX_CNT; i++) aux[i] = 0; |
| for (i=0; auxv[i]; i+=2) if (auxv[i]<AUX_CNT) |
| aux[auxv[i]] = auxv[i+1]; |
| |
| for (i=0; i<DYN_CNT; i++) dyn[i] = 0; |
| for (i=0; dynv[i]; i+=2) if (dynv[i]<DYN_CNT) |
| dyn[dynv[i]] = dynv[i+1]; |
| |
| /* If the dynamic linker is invoked as a command, its load |
| * address is not available in the aux vector. Instead, compute |
| * the load address as the difference between &_DYNAMIC and the |
| * virtual address in the PT_DYNAMIC program header. */ |
| base = aux[AT_BASE]; |
| if (!base) { |
| size_t phnum = aux[AT_PHNUM]; |
| size_t phentsize = aux[AT_PHENT]; |
| Phdr *ph = (void *)aux[AT_PHDR]; |
| for (i=phnum; i--; ph = (void *)((char *)ph + phentsize)) { |
| if (ph->p_type == PT_DYNAMIC) { |
| base = (size_t)dynv - ph->p_vaddr; |
| break; |
| } |
| } |
| } |
| |
| /* MIPS uses an ugly packed form for GOT relocations. Since we |
| * can't make function calls yet and the code is tiny anyway, |
| * it's simply inlined here. */ |
| if (NEED_MIPS_GOT_RELOCS) { |
| size_t local_cnt = 0; |
| size_t *got = (void *)(base + dyn[DT_PLTGOT]); |
| for (i=0; dynv[i]; i+=2) if (dynv[i]==DT_MIPS_LOCAL_GOTNO) |
| local_cnt = dynv[i+1]; |
| for (i=0; i<local_cnt; i++) got[i] += base; |
| } |
| |
| rel = (void *)(base+dyn[DT_REL]); |
| rel_size = dyn[DT_RELSZ]; |
| for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t)) { |
| if (!IS_RELATIVE(rel[1])) continue; |
| size_t *rel_addr = (void *)(base + rel[0]); |
| *rel_addr += base; |
| } |
| |
| rel = (void *)(base+dyn[DT_RELA]); |
| rel_size = dyn[DT_RELASZ]; |
| for (; rel_size; rel+=3, rel_size-=3*sizeof(size_t)) { |
| if (!IS_RELATIVE(rel[1])) continue; |
| size_t *rel_addr = (void *)(base + rel[0]); |
| *rel_addr = base + rel[2]; |
| } |
| |
| stage2_func dls2; |
| GETFUNCSYM(&dls2, __dls2, base+dyn[DT_PLTGOT]); |
| dls2((void *)base, sp); |
| } |
| |
| #endif |