elf: Fix dynamic-link.h usage on rtld.c

The 4af6982e4c fix does not fully handle RTLD_BOOTSTRAP usage on
rtld.c due two issues:

  1. RTLD_BOOTSTRAP is also used on dl-machine.h on various
     architectures and it changes the semantics of various machine
     relocation functions.

  2. The elf_get_dynamic_info() change was done sideways, previously
     to 490e6c62aa get-dynamic-info.h was included by the first
     dynamic-link.h include *without* RTLD_BOOTSTRAP being defined.
     It means that the code within elf_get_dynamic_info() that uses
     RTLD_BOOTSTRAP is in fact unused.

To fix 1. this patch now includes dynamic-link.h only once with
RTLD_BOOTSTRAP defined.  The ELF_DYNAMIC_RELOCATE call will now have
the relocation fnctions with the expected semantics for the loader.

And to fix 2. part of 4af6982e4c is reverted (the check argument
elf_get_dynamic_info() is not required) and the RTLD_BOOTSTRAP
pieces are removed.

To reorganize the includes the static TLS definition is moved to
its own header to avoid a circular dependency (it is defined on
dynamic-link.h and dl-machine.h requires it at same time other
dynamic-link.h definition requires dl-machine.h defitions).

Also ELF_MACHINE_NO_REL, ELF_MACHINE_NO_RELA, and ELF_MACHINE_PLT_REL
are moved to its own header.  Only ancient ABIs need special values
(arm, i386, and mips), so a generic one is used as default.

The powerpc Elf64_FuncDesc is also moved to its own header, since
csu code required its definition (which would require either include
elf/ folder or add a full path with elf/).

Checked on x86_64, i686, aarch64, armhf, powerpc64, powerpc32,
and powerpc64le.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>

1 files changed, 11 insertions, 12 deletions

diff --git a/elf/rtld.c b/elf/rtld.c
index fe5ee9ec4d..6cfb7cf672 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -32,7 +32,6 @@
 #include <fpu_control.h>
 #include <hp-timing.h>
 #include <libc-lock.h>
-#include "dynamic-link.h"
 #include <dl-librecon.h>
 #include <unsecvars.h>
 #include <dl-cache.h>
@@ -50,9 +49,18 @@
 #include <dl-main.h>
 #include <gnu/lib-names.h>
 #include <dl-tunables.h>
+#include <get-dynamic-info.h>
 
 #include <assert.h>
 
+/* This #define produces dynamic linking inline functions for
+   bootstrap relocation instead of general-purpose relocation.
+   Since ld.so must not have any undefined symbols the result
+   is trivial: always the map of ld.so itself.  */
+#define RTLD_BOOTSTRAP
+#define RESOLVE_MAP(map, scope, sym, version, flags) map
+#include "dynamic-link.h"
+
 /* Only enables rtld profiling for architectures which provides non generic
    hp-timing support.  The generic support requires either syscall
    (clock_gettime), which will incur in extra overhead on loading time.
@@ -507,15 +515,6 @@ _dl_start_final (void *arg, struct dl_start_final_info *info)
 # define bootstrap_map info.l
 #endif
 
-  /* This #define produces dynamic linking inline functions for
-     bootstrap relocation instead of general-purpose relocation.
-     Since ld.so must not have any undefined symbols the result
-     is trivial: always the map of ld.so itself.  */
-#define RTLD_BOOTSTRAP
-#define RESOLVE_MAP(map, scope, sym, version, flags) map
-#include "get-dynamic-info.h"
-#include "dynamic-link.h"
-
 static ElfW(Addr) __attribute_used__
 _dl_start (void *arg)
 {
@@ -548,7 +547,7 @@ _dl_start (void *arg)
 
   /* Read our own dynamic section and fill in the info array.  */
   bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
-  elf_get_dynamic_info (&bootstrap_map, true);
+  elf_get_dynamic_info (&bootstrap_map);
 
 #if NO_TLS_OFFSET != 0
   bootstrap_map.l_tls_offset = NO_TLS_OFFSET;
@@ -1616,7 +1615,7 @@ dl_main (const ElfW(Phdr) *phdr,
   if (! rtld_is_main)
     {
       /* Extract the contents of the dynamic section for easy access.  */
-      elf_get_dynamic_info (main_map, false);
+      elf_get_dynamic_info (main_map);
 
       /* If the main map is libc.so, update the base namespace to
 	 refer to this map.  If libc.so is loaded later, this happens