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authorUlrich Drepper <drepper@redhat.com>1999-07-09 14:34:22 +0000
committerUlrich Drepper <drepper@redhat.com>1999-07-09 14:34:22 +0000
commit6a1db4ffb67ccb8c3861bb398bff5a033f2d7793 (patch)
treeb185c6ef1324c87cf9917efbcd962c796f78d426 /elf
parent56ad7b2ceccc199811378d9033a8fbb7bcc1cc4c (diff)
downloadglibc-6a1db4ffb67ccb8c3861bb398bff5a033f2d7793.tar.gz
Update.
* elf/rtld.c: Split _dl_start in two pieces to prevent GOT usage before the relocation happened. Patch by Franz Sirl <Franz.Sirl-kernel@lauterbach.com>.
Diffstat (limited to 'elf')
-rw-r--r--elf/rtld.c31
1 files changed, 24 insertions, 7 deletions
diff --git a/elf/rtld.c b/elf/rtld.c
index 064cd20dd3..4146c0e9bf 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.