From 6a1db4ffb67ccb8c3861bb398bff5a033f2d7793 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Fri, 9 Jul 1999 14:34:22 +0000 Subject: Update. * elf/rtld.c: Split _dl_start in two pieces to prevent GOT usage before the relocation happened. Patch by Franz Sirl . --- elf/rtld.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-) (limited to 'elf') diff --git a/elf/rtld.c b/elf/rtld.c index 064cd20..4146c0e 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -129,6 +129,9 @@ static hp_timing_t relocate_time; static hp_timing_t load_time; extern unsigned long int _dl_num_relocations; /* in dl-lookup.c */ +static ElfW(Addr) _dl_start_final (void *arg, struct link_map *bootstrap_map_p, + hp_timing_t start_time); + #ifdef RTLD_START RTLD_START #else @@ -140,7 +143,6 @@ _dl_start (void *arg) { struct link_map bootstrap_map; hp_timing_t start_time; - ElfW(Addr) start_addr; /* This #define produces dynamic linking inline functions for bootstrap relocation instead of general-purpose relocation. */ @@ -175,7 +177,22 @@ _dl_start (void *arg) /* Now life is sane; we can call functions and access global data. Set up to use the operating system facilities, and find out from the operating system's program loader where to find the program - header table in core. */ + header table in core. Put the rest of _dl_start into a separate + function, that way the compiler cannot put accesses to the GOT + before ELF_DYNAMIC_RELOCATE. */ + return _dl_start_final (arg, &bootstrap_map, start_time); +} + + +static ElfW(Addr) +_dl_start_final (void *arg, struct link_map *bootstrap_map_p, + hp_timing_t start_time) +{ + /* The use of `alloca' here looks ridiculous but it helps. The goal + is to avoid the function from being inlined. There is no official + way to do this so we use this trick. gcc never inlines functions + which use `alloca'. */ + ElfW(Addr) *start_addr = alloca (sizeof (ElfW(Addr))); if (HP_TIMING_AVAIL) { @@ -188,10 +205,10 @@ _dl_start (void *arg) } /* Transfer data about ourselves to the permanent link_map structure. */ - _dl_rtld_map.l_addr = bootstrap_map.l_addr; - _dl_rtld_map.l_ld = bootstrap_map.l_ld; + _dl_rtld_map.l_addr = bootstrap_map_p->l_addr; + _dl_rtld_map.l_ld = bootstrap_map_p->l_ld; _dl_rtld_map.l_opencount = 1; - memcpy (_dl_rtld_map.l_info, bootstrap_map.l_info, + memcpy (_dl_rtld_map.l_info, bootstrap_map_p->l_info, sizeof _dl_rtld_map.l_info); _dl_setup_hash (&_dl_rtld_map); @@ -203,7 +220,7 @@ _dl_start (void *arg) file access. It will call `dl_main' (below) to do all the real work of the dynamic linker, and then unwind our frame and run the user entry point on the same stack we entered on. */ - start_addr = _dl_sysdep_start (arg, &dl_main); + *start_addr = _dl_sysdep_start (arg, &dl_main); if (HP_TIMING_AVAIL) { @@ -219,7 +236,7 @@ _dl_start (void *arg) if (_dl_debug_statistics) print_statistics (); - return start_addr; + return *start_addr; } /* Now life is peachy; we can do all normal operations. -- cgit v1.1