diff options
Diffstat (limited to 'elf')
| -rw-r--r-- | elf/rtld.c | 58 |
1 files changed, 45 insertions, 13 deletions
diff --git a/elf/rtld.c b/elf/rtld.c index f0f228f352..44fbf3e53a 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -115,6 +115,7 @@ static struct libname_list _dl_rtld_libname2; static hp_timing_t rtld_total_time; static hp_timing_t relocate_time; static hp_timing_t load_time; +static hp_timing_t start_time; #endif /* Additional definitions needed by TLS initialization. */ @@ -122,8 +123,22 @@ static hp_timing_t load_time; TLS_INIT_HELPER #endif -static ElfW(Addr) _dl_start_final (void *arg, struct link_map *bootstrap_map_p, - hp_timing_t start_time); +/* Before ld.so is relocated we must not access variables which need + relocations. This means variables which are exported. Variables + declared as static are fine. If we can mark a variable hidden this + is fine, too. The latter is impotant here. We can avoid setting + up a temporary link map for ld.so if we can mark _rtld_global as + hidden. */ +#ifdef HAVE_HIDDEN +# define DONT_USE_BOOTSTRAP_MAP 1 +#endif + +#ifdef DONT_USE_BOOTSTRAP_MAP +static ElfW(Addr) _dl_start_final (void *arg); +#else +static ElfW(Addr) _dl_start_final (void *arg, + struct link_map *bootstrap_map_p); +#endif #ifdef RTLD_START RTLD_START @@ -134,8 +149,11 @@ RTLD_START static ElfW(Addr) __attribute_used__ internal_function _dl_start (void *arg) { +#ifdef DONT_USE_BOOTSTRAP_MAP +# define bootstrap_map GL(dl_rtld_map) +#else struct link_map bootstrap_map; - hp_timing_t start_time; +#endif #if !defined HAVE_BUILTIN_MEMSET || defined USE_TLS size_t cnt; #endif @@ -160,14 +178,18 @@ _dl_start (void *arg) /* Partly clean the `bootstrap_map' structure up. Don't use `memset' since it might not be built in or inlined and we cannot make function calls at this point. Use '__builtin_memset' if we - know it is available. */ -#ifdef HAVE_BUILTIN_MEMSET + know it is available. We do not have to clear the memory if we + do not have to use the temporary bootstrap_map. Global variables + are initialized to zero by default. */ +#ifndef DONT_USE_BOOTSTRAP_MAP +# ifdef HAVE_BUILTIN_MEMSET __builtin_memset (bootstrap_map.l_info, '\0', sizeof (bootstrap_map.l_info)); -#else +# else for (cnt = 0; cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]); ++cnt) bootstrap_map.l_info[cnt] = 0; +# endif #endif /* Figure out the run-time load address of the dynamic linker itself. */ @@ -178,7 +200,7 @@ _dl_start (void *arg) elf_get_dynamic_info (&bootstrap_map); #if USE_TLS -# ifndef HAVE___THREAD +# if !defined HAVE___THREAD && !defined DONT_USE_BOOTSTRAP_MAP /* Signal that we have not found TLS data so far. */ bootstrap_map.l_tls_modid = 0; # endif @@ -306,7 +328,11 @@ _dl_start (void *arg) function, that way the compiler cannot put accesses to the GOT before ELF_DYNAMIC_RELOCATE. */ { - ElfW(Addr) entry = _dl_start_final (arg, &bootstrap_map, start_time); +#ifdef DONT_USE_BOOTSTRAP_MAP + ElfW(Addr) entry = _dl_start_final (arg); +#else + ElfW(Addr) entry = _dl_start_final (arg, &bootstrap_map); +#endif #ifndef ELF_MACHINE_START_ADDRESS # define ELF_MACHINE_START_ADDRESS(map, start) (start) @@ -326,9 +352,13 @@ _dl_start (void *arg) + DT_EXTRANUM + DT_VALNUM + DT_ADDRTAGIDX (tag)) #endif +#ifdef DONT_USE_BOOTSTRAP_MAP +static ElfW(Addr) +_dl_start_final (void *arg) +#else static ElfW(Addr) -_dl_start_final (void *arg, struct link_map *bootstrap_map_p, - hp_timing_t start_time) +_dl_start_final (void *arg, struct link_map *bootstrap_map_p) +#endif { /* The use of `alloca' here looks ridiculous but it helps. The goal is to avoid the function from being inlined. There is no official @@ -349,17 +379,19 @@ _dl_start_final (void *arg, struct link_map *bootstrap_map_p, } /* Transfer data about ourselves to the permanent link_map structure. */ +#ifndef DONT_USE_BOOTSTRAP_MAP GL(dl_rtld_map).l_addr = bootstrap_map_p->l_addr; GL(dl_rtld_map).l_ld = bootstrap_map_p->l_ld; - GL(dl_rtld_map).l_opencount = 1; memcpy (GL(dl_rtld_map).l_info, bootstrap_map_p->l_info, sizeof GL(dl_rtld_map).l_info); - _dl_setup_hash (&GL(dl_rtld_map)); GL(dl_rtld_map).l_mach = bootstrap_map_p->l_mach; +#endif + _dl_setup_hash (&GL(dl_rtld_map)); + GL(dl_rtld_map).l_opencount = 1; GL(dl_rtld_map).l_map_start = (ElfW(Addr)) _begin; GL(dl_rtld_map).l_map_end = (ElfW(Addr)) _end; /* Copy the TLS related data if necessary. */ -#if USE_TLS +#if USE_TLS && !defined DONT_USE_BOOTSTRAP_MAP # ifdef HAVE___THREAD assert (bootstrap_map_p->l_tls_modid != 0); # else |