Rtld on diet 3.

Stop using strerror(3) in rtld, which brings in msgcat and stdio.
Directly access sys_errlist array of errno messages with private
rtld_strerror() function.

Now,
$ size /libexec/ld-elf.so.1
   text    data     bss     dec     hex filename
  96983    2480    8744  108207   1a6af /libexec/ld-elf.so.1

Reviewed by:	dim, kan
MFC after:	2 weeks

1 files changed, 12 insertions, 3 deletions

diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c
index 1ca5ba0..3432232 100644
--- a/libexec/rtld-elf/rtld.c
+++ b/libexec/rtld-elf/rtld.c
@@ -2163,7 +2163,7 @@ relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj,
 	    if (mprotect(obj->mapbase, obj->textsize,
 	      PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
 		_rtld_error("%s: Cannot write-enable text segment: %s",
-		  obj->path, strerror(errno));
+		  obj->path, rtld_strerror(errno));
 		return -1;
 	    }
 	}
@@ -2176,7 +2176,7 @@ relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj,
 	    if (mprotect(obj->mapbase, obj->textsize,
 	      PROT_READ|PROT_EXEC) == -1) {
 		_rtld_error("%s: Cannot write-protect text segment: %s",
-		  obj->path, strerror(errno));
+		  obj->path, rtld_strerror(errno));
 		return -1;
 	    }
 	}
@@ -2196,7 +2196,7 @@ relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj,
 	if (obj->relro_size > 0) {
 	    if (mprotect(obj->relro_page, obj->relro_size, PROT_READ) == -1) {
 		_rtld_error("%s: Cannot enforce relro protection: %s",
-		  obj->path, strerror(errno));
+		  obj->path, rtld_strerror(errno));
 		return -1;
 	    }
 	}
@@ -4353,3 +4353,12 @@ __chk_fail(void)
 	_rtld_error("buffer overflow detected; terminated");
 	die();
 }
+
+const char *
+rtld_strerror(int errnum)
+{
+
+	if (errnum < 0 || errnum >= sys_nerr)
+		return ("Unknown error");
+	return (sys_errlist[errnum]);
+}