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Split _dl_start in two pieces to prevent GOT usage before the relocation

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happened.
This commit is contained in:
Ulrich Drepper 1999-07-09 14:36:08 +00:00
parent b329794bfd
commit da196a5b5f
1 changed files with 24 additions and 7 deletions
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31
elf/rtld.c
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@ -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.