elf: Avoid nested functions in the loader [BZ #27220]

dynamic-link.h is included more than once in some elf/ files (rtld.c,
dl-conflict.c, dl-reloc.c, dl-reloc-static-pie.c) and uses GCC nested
functions. This harms readability and the nested functions usage
is the biggest obstacle prevents Clang build (Clang doesn't support GCC
nested functions).

The key idea for unnesting is to add extra parameters (struct link_map
*and struct r_scope_elm *[]) to RESOLVE_MAP,
ELF_MACHINE_BEFORE_RTLD_RELOC, ELF_DYNAMIC_RELOCATE, elf_machine_rel[a],
elf_machine_lazy_rel, and elf_machine_runtime_setup. (This is inspired
by Stan Shebs' ppc64/x86-64 implementation in the
google/grte/v5-2.27/master which uses mixed extra parameters and static
variables.)

Future simplification:
* If mips elf_machine_runtime_setup no longer needs RESOLVE_GOTSYM,
  elf_machine_runtime_setup can drop the `scope` parameter.
* If TLSDESC no longer need to be in elf_machine_lazy_rel,
  elf_machine_lazy_rel can drop the `scope` parameter.

Tested on aarch64, i386, x86-64, powerpc64le, powerpc64, powerpc32,
sparc64, sparcv9, s390x, s390, hppa, ia64, armhf, alpha, and mips64.
In addition, tested build-many-glibcs.py with {arc,csky,microblaze,nios2}-linux-gnu
and riscv64-linux-gnu-rv64imafdc-lp64d.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

2 files changed, 19 insertions, 17 deletions

diff --git a/sysdeps/powerpc/powerpc32/dl-machine.h b/sysdeps/powerpc/powerpc32/dl-machine.h
index b93cf48..cda012d 100644
--- a/sysdeps/powerpc/powerpc32/dl-machine.h
+++ b/sysdeps/powerpc/powerpc32/dl-machine.h
@@ -170,7 +170,7 @@ extern int __elf_machine_runtime_setup (struct link_map *map,
 					int lazy, int profile);
 
 static inline int
-elf_machine_runtime_setup (struct link_map *map,
+elf_machine_runtime_setup (struct link_map *map, struct r_scope_elem *scope[],
 			   int lazy, int profile)
 {
   if (map->l_info[DT_JMPREL] == 0)
@@ -284,9 +284,10 @@ extern void _dl_reloc_overflow (struct link_map *map,
    LOADADDR is the load address of the object; INFO is an array indexed
    by DT_* of the .dynamic section info.  */
 
-auto inline void __attribute__ ((always_inline))
-elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
-		  const Elf32_Sym *sym, const struct r_found_version *version,
+static inline void __attribute__ ((always_inline))
+elf_machine_rela (struct link_map *map, struct r_scope_elem *scope[],
+		  const Elf32_Rela *reloc, const Elf32_Sym *sym,
+		  const struct r_found_version *version,
 		  void *const reloc_addr_arg, int skip_ifunc)
 {
   Elf32_Addr *const reloc_addr = reloc_addr_arg;
@@ -315,7 +316,7 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
     }
   else
     {
-      sym_map = RESOLVE_MAP (&sym, version, r_type);
+      sym_map = RESOLVE_MAP (map, scope, &sym, version, r_type);
       value = SYMBOL_ADDRESS (sym_map, sym, true);
     }
   value += reloc->r_addend;
@@ -439,7 +440,7 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
     }
 }
 
-auto inline void __attribute__ ((always_inline))
+static inline void __attribute__ ((always_inline))
 elf_machine_rela_relative (Elf32_Addr l_addr, const Elf32_Rela *reloc,
 			   void *const reloc_addr_arg)
 {
@@ -447,8 +448,8 @@ elf_machine_rela_relative (Elf32_Addr l_addr, const Elf32_Rela *reloc,
   *reloc_addr = l_addr + reloc->r_addend;
 }
 
-auto inline void __attribute__ ((always_inline))
-elf_machine_lazy_rel (struct link_map *map,
+static inline void __attribute__ ((always_inline))
+elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[],
 		      Elf32_Addr l_addr, const Elf32_Rela *reloc,
 		      int skip_ifunc)
 {
diff --git a/sysdeps/powerpc/powerpc64/dl-machine.h b/sysdeps/powerpc/powerpc64/dl-machine.h
index b3f3352..3f92fbb 100644
--- a/sysdeps/powerpc/powerpc64/dl-machine.h
+++ b/sysdeps/powerpc/powerpc64/dl-machine.h
@@ -343,7 +343,8 @@ dl_platform_init (void)
 /* Set up the loaded object described by MAP so its unrelocated PLT
    entries will jump to the on-demand fixup code in dl-runtime.c.  */
 static inline int __attribute__ ((always_inline))
-elf_machine_runtime_setup (struct link_map *map, int lazy, int profile)
+elf_machine_runtime_setup (struct link_map *map, struct r_scope_elem *scope[],
+			   int lazy, int profile)
 {
   if (map->l_info[DT_JMPREL])
     {
@@ -618,7 +619,7 @@ extern void attribute_hidden _dl_reloc_overflow (struct link_map *map,
 						 Elf64_Addr *const reloc_addr,
 						 const Elf64_Sym *refsym);
 
-auto inline void __attribute__ ((always_inline))
+static inline void __attribute__ ((always_inline))
 elf_machine_rela_relative (Elf64_Addr l_addr, const Elf64_Rela *reloc,
 			   void *const reloc_addr_arg)
 {
@@ -627,7 +628,7 @@ elf_machine_rela_relative (Elf64_Addr l_addr, const Elf64_Rela *reloc,
 }
 
 /* This computes the value used by TPREL* relocs.  */
-auto inline Elf64_Addr __attribute__ ((always_inline, const))
+static inline Elf64_Addr __attribute__ ((always_inline, const))
 elf_machine_tprel (struct link_map *map,
 		   struct link_map *sym_map,
 		   const Elf64_Sym *sym,
@@ -646,7 +647,7 @@ elf_machine_tprel (struct link_map *map,
 }
 
 /* Call function at address VALUE (an OPD entry) to resolve ifunc relocs.  */
-auto inline Elf64_Addr __attribute__ ((always_inline))
+static inline Elf64_Addr __attribute__ ((always_inline))
 resolve_ifunc (Elf64_Addr value,
 	       const struct link_map *map, const struct link_map *sym_map)
 {
@@ -676,8 +677,8 @@ resolve_ifunc (Elf64_Addr value,
 
 /* Perform the relocation specified by RELOC and SYM (which is fully
    resolved).  MAP is the object containing the reloc.  */
-auto inline void __attribute__ ((always_inline))
-elf_machine_rela (struct link_map *map,
+static inline void __attribute__ ((always_inline))
+elf_machine_rela (struct link_map *map, struct r_scope_elem *scope[],
 		  const Elf64_Rela *reloc,
 		  const Elf64_Sym *sym,
 		  const struct r_found_version *version,
@@ -705,7 +706,7 @@ elf_machine_rela (struct link_map *map,
 
   /* We need SYM_MAP even in the absence of TLS, for elf_machine_fixup_plt
      and STT_GNU_IFUNC.  */
-  struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
+  struct link_map *sym_map = RESOLVE_MAP (map, scope, &sym, version, r_type);
   Elf64_Addr value = SYMBOL_ADDRESS (sym_map, sym, true) + reloc->r_addend;
 
   if (sym != NULL
@@ -1035,8 +1036,8 @@ elf_machine_rela (struct link_map *map,
   MODIFIED_CODE_NOQUEUE (reloc_addr);
 }
 
-auto inline void __attribute__ ((always_inline))
-elf_machine_lazy_rel (struct link_map *map,
+static inline void __attribute__ ((always_inline))
+elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[],
 		      Elf64_Addr l_addr, const Elf64_Rela *reloc,
 		      int skip_ifunc)
 {