elf: Use dl-symbol-redir-ifunc.h instead _dl_strlenHEADmaster

Also replace the loop with strlen And remove
-fno-tree-loop-distribute-patterns usage.

It requires redirect the strlen to the baseline implementation
for x86_64, aarch64, and loongarch64.

Checked on x86_64-linux-gnu{-v2,v3} and aarch64-linux-gnu with
both gcc-15 and clang-21.

Reviewed-by: DJ Delorie <dj@redhat.com>

2 files changed, 1 insertions, 19 deletions

diff --git a/elf/Makefile b/elf/Makefile
index 396e97b..1a0ed49 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -97,12 +97,6 @@ ifeq (yesyes,$(build-shared)$(run-built-tests))
 tests-special += $(objpfx)list-tunables.out
 endif
 
-# Make sure that the compiler does not insert any library calls in tunables
-# code paths.
-ifeq (yes,$(have-loop-to-function))
-CFLAGS-dl-tunables.c += -fno-tree-loop-distribute-patterns
-endif
-
 all-dl-routines = $(dl-routines) $(sysdep-dl-routines)
 # But they are absent from the shared libc, because that code is in ld.so.
 elide-routines.os = \
diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c
index 37ade37..bdb1de4 100644
--- a/elf/dl-tunables.c
+++ b/elf/dl-tunables.c
@@ -37,16 +37,6 @@
 #define TUNABLES_INTERNAL 1
 #include "dl-tunables.h"
 
-/* The function might be called before the process is self-relocated.  */
-static size_t
-__attribute_optimization_barrier__
-_dl_strlen (const char *s)
-{
-  const char *p = s;
-  for (; *s != '\0'; s++);
-  return s - p;
-}
-
 static char **
 get_next_env (char **envp, char **name, char **val, char ***prev_envp)
 {
@@ -335,10 +325,8 @@ __tunables_init (char **envp)
 	  if (tunable_is_name (name, envname))
 	    {
 	      /* The environment variable is always null-terminated.  */
-	      size_t envvallen = _dl_strlen (envval);
-
 	      tunables_env_alias[i] =
-		(struct tunable_toset_t) { cur, envval, envvallen };
+		(struct tunable_toset_t) { cur, envval, strlen (envval) };
 	      break;
 	    }
 	}