rtld: allow arches to initialize/finalize objects

Discussed with:	jrtc27
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D59269

libexec/rtld-elf/aarch64/rtld_machdep.h

@@ -41,6 +41,9 @@ struct Struct_Obj_Entry;
 #define	MD_OBJ_ENTRY	\
     bool variant_pcs : 1;	/* Object has a variant pcs function */
 
+#define	MD_OBJ_ENTRY_INIT(obj)
+#define	MD_OBJ_ENTRY_FINI(obj)
+
 /* Return the address of the .dynamic section in the dynamic linker. */
 #define	rtld_dynamic(obj)						\
 ({									\

libexec/rtld-elf/amd64/rtld_machdep.h

@@ -37,6 +37,9 @@ struct Struct_Obj_Entry;
 
 #define	MD_OBJ_ENTRY
 
+#define	MD_OBJ_ENTRY_INIT(obj)
+#define	MD_OBJ_ENTRY_FINI(obj)
+
 /* Return the address of the .dynamic section in the dynamic linker. */
 Elf_Dyn *rtld_dynamic_addr(void);
 #define	rtld_dynamic(obj)	rtld_dynamic_addr()

libexec/rtld-elf/arm/rtld_machdep.h

@@ -38,6 +38,9 @@ struct Struct_Obj_Entry;
 
 #define	MD_OBJ_ENTRY
 
+#define	MD_OBJ_ENTRY_INIT(obj)
+#define	MD_OBJ_ENTRY_FINI(obj)
+
 /* Return the address of the .dynamic section in the dynamic linker. */
 #define rtld_dynamic(obj) (&_DYNAMIC)
 

libexec/rtld-elf/i386/rtld_machdep.h

@@ -37,6 +37,9 @@ struct Struct_Obj_Entry;
 
 #define	MD_OBJ_ENTRY
 
+#define	MD_OBJ_ENTRY_INIT(obj)
+#define	MD_OBJ_ENTRY_FINI(obj)
+
 /* Return the address of the .dynamic section in the dynamic linker. */
 #define rtld_dynamic(obj) \
     ((const Elf_Dyn *)((obj)->relocbase + (Elf_Addr)&_DYNAMIC))

libexec/rtld-elf/map_object.c

@@ -482,6 +482,7 @@ obj_free(Obj_Entry *obj)
 		free(obj->path);
 	if (obj->phdr_alloc)
 		free(__DECONST(void *, obj->phdr));
+	MD_OBJ_ENTRY_FINI(obj);
 	free(obj);
 }
 
@@ -494,6 +495,7 @@ obj_new(void)
 	STAILQ_INIT(&obj->dldags);
 	STAILQ_INIT(&obj->dagmembers);
 	STAILQ_INIT(&obj->names);
+	MD_OBJ_ENTRY_INIT(obj);
 	return (obj);
 }
 

libexec/rtld-elf/powerpc/rtld_machdep.h

@@ -38,6 +38,9 @@ struct Struct_Obj_Entry;
 #define	MD_OBJ_ENTRY	\
     Elf_Addr *gotptr;		/* GOT pointer (secure-plt only) */
 
+#define	MD_OBJ_ENTRY_INIT(obj)
+#define	MD_OBJ_ENTRY_FINI(obj)
+
 /* Return the address of the .dynamic section in the dynamic linker. */
 #define rtld_dynamic(obj)    (&_DYNAMIC)
 

libexec/rtld-elf/powerpc64/rtld_machdep.h

@@ -38,6 +38,9 @@ struct Struct_Obj_Entry;
 #define	MD_OBJ_ENTRY	\
     Elf_Addr glink;		/* GLINK PLT call stub section */
 
+#define	MD_OBJ_ENTRY_INIT(obj)
+#define	MD_OBJ_ENTRY_FINI(obj)
+
 /* Return the address of the .dynamic section in the dynamic linker. */
 #define rtld_dynamic(obj)    (&_DYNAMIC)
 

libexec/rtld-elf/riscv/rtld_machdep.h

@@ -44,6 +44,9 @@ struct Struct_Obj_Entry;
 
 #define	MD_OBJ_ENTRY
 
+#define	MD_OBJ_ENTRY_INIT(obj)
+#define	MD_OBJ_ENTRY_FINI(obj)
+
 uint64_t set_gp(struct Struct_Obj_Entry *obj);
 
 /* Return the address of the .dynamic section in the dynamic linker. */