diff options
| -rw-r--r-- | src/ldso/dynlink.c | 33 |
1 files changed, 31 insertions, 2 deletions
diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c index 226e174f..d8f641ae 100644 --- a/src/ldso/dynlink.c +++ b/src/ldso/dynlink.c @@ -298,7 +298,7 @@ static struct dso *load_library(const char *name) if (!libc->prev) { tail->next = libc; libc->prev = tail; - tail = libc; + tail = libc->next ? libc->next : libc; } return libc; } @@ -440,12 +440,15 @@ void *__dynlink(int argc, char **argv, size_t *got) size_t *auxv, aux[AUX_CNT] = {0}; size_t app_dyn[DYN_CNT] = {0}; size_t lib_dyn[DYN_CNT] = {0}; + size_t vdso_dyn[DYN_CNT] = {0}; size_t i; Phdr *phdr; Ehdr *ehdr; - static struct dso builtin_dsos[2]; + static struct dso builtin_dsos[3]; struct dso *const app = builtin_dsos+0; struct dso *const lib = builtin_dsos+1; + struct dso *const vdso = builtin_dsos+2; + size_t vdso_base=0; /* Find aux vector just past environ[] */ for (i=argc+1; argv[i]; i++) @@ -455,6 +458,13 @@ void *__dynlink(int argc, char **argv, size_t *got) decode_vec(auxv, aux, AUX_CNT); + for (i=0; auxv[i]; i+=2) { + if (auxv[i]==AT_SYSINFO_EHDR) { + vdso_base = auxv[i+1]; + break; + } + } + /* Only trust user/env if kernel says we're not suid/sgid */ if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID] || aux[AT_GID]!=aux[AT_EGID]) { @@ -495,6 +505,25 @@ void *__dynlink(int argc, char **argv, size_t *got) .relocated = 1 }; + if (vdso_base) { + ehdr = (void *)vdso_base; + phdr = (void *)(vdso_base + ehdr->e_phoff); + for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) { + if (phdr->p_type == PT_DYNAMIC) + vdso->dynv = (void *)(vdso_base + phdr->p_offset); + if (phdr->p_type == PT_LOAD) + vdso->base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset); + } + decode_vec(vdso->dynv, vdso_dyn, DYN_CNT); + vdso->syms = (void *)(vdso->base + vdso_dyn[DT_SYMTAB]); + vdso->hashtab = (void *)(vdso->base + vdso_dyn[DT_HASH]); + vdso->strings = (void *)(vdso->base + vdso_dyn[DT_STRTAB]); + vdso->name = "linux-gate.so.1"; + + vdso->prev = lib; + lib->next = vdso; + } + /* Relocate the dynamic linker/libc */ do_relocs((void *)aux[AT_BASE], (void *)(aux[AT_BASE]+lib_dyn[DT_REL]), lib_dyn[DT_RELSZ], 2, lib->syms, lib->strings, app); |