Module Name: src
Committed By: kamil
Date: Mon Sep 21 16:08:57 UTC 2020
Modified Files:
src/include: link_elf.h
src/libexec/ld.elf_so: load.c rtld.c rtld.h
Log Message:
Upgrade the SVR4 RTLD r_debug protocol to version 1
Changes:
- Add a new field r_ldbase in the r_debug struct.
- Set r_version to 1.
This harmonizes the support with OpenBSD and Linux.
FreeBSD uses version 0 (or no version).
Solaris uses version 2 that is not implemented elsewhere and relies on
SVR4 specific design and interfaces.
Update the code comments as r_debug and link_map is used by other software
than GDB, namely: sanitizers, rump, LLDB.
To generate a diff of this commit:
cvs rdiff -u -r1.11 -r1.12 src/include/link_elf.h
cvs rdiff -u -r1.48 -r1.49 src/libexec/ld.elf_so/load.c
cvs rdiff -u -r1.205 -r1.206 src/libexec/ld.elf_so/rtld.c
cvs rdiff -u -r1.140 -r1.141 src/libexec/ld.elf_so/rtld.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/include/link_elf.h
diff -u src/include/link_elf.h:1.11 src/include/link_elf.h:1.12
--- src/include/link_elf.h:1.11 Mon Sep 21 02:20:27 2020
+++ src/include/link_elf.h Mon Sep 21 16:08:57 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: link_elf.h,v 1.11 2020/09/21 02:20:27 kamil Exp $ */
+/* $NetBSD: link_elf.h,v 1.12 2020/09/21 16:08:57 kamil Exp $ */
#ifndef _LINK_ELF_H_
#define _LINK_ELF_H_
@@ -6,6 +6,8 @@
#include <sys/types.h>
#include <sys/exec_elf.h>
+#define R_DEBUG_VERSION 1 /* SVR4 Protocol version */
+
typedef struct link_map {
caddr_t l_addr; /* Base Address of library */
#ifdef __mips__
@@ -43,6 +45,7 @@ struct r_debug {
RT_ADD, /* adding a shared library */
RT_DELETE /* removing a shared library */
} r_state;
+ void *r_ldbase; /* base address of RTLD */
};
struct dl_phdr_info
Index: src/libexec/ld.elf_so/load.c
diff -u src/libexec/ld.elf_so/load.c:1.48 src/libexec/ld.elf_so/load.c:1.49
--- src/libexec/ld.elf_so/load.c:1.48 Tue Jan 10 21:08:48 2017
+++ src/libexec/ld.elf_so/load.c Mon Sep 21 16:08:57 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: load.c,v 1.48 2017/01/10 21:08:48 christos Exp $ */
+/* $NetBSD: load.c,v 1.49 2020/09/21 16:08:57 kamil Exp $ */
/*
* Copyright 1996 John D. Polstra.
@@ -40,7 +40,7 @@
#include <sys/cdefs.h>
#ifndef lint
-__RCSID("$NetBSD: load.c,v 1.48 2017/01/10 21:08:48 christos Exp $");
+__RCSID("$NetBSD: load.c,v 1.49 2020/09/21 16:08:57 kamil Exp $");
#endif /* not lint */
#include <sys/types.h>
@@ -180,7 +180,7 @@ _rtld_load_object(const char *filepath,
_rtld_objcount++;
_rtld_objloads++;
#ifdef RTLD_LOADER
- _rtld_linkmap_add(obj); /* for GDB */
+ _rtld_linkmap_add(obj); /* for the debugger */
#endif
dbg((" %p .. %p: %s", obj->mapbase,
obj->mapbase + obj->mapsize - 1, obj->path));
Index: src/libexec/ld.elf_so/rtld.c
diff -u src/libexec/ld.elf_so/rtld.c:1.205 src/libexec/ld.elf_so/rtld.c:1.206
--- src/libexec/ld.elf_so/rtld.c:1.205 Sun Apr 19 01:06:15 2020
+++ src/libexec/ld.elf_so/rtld.c Mon Sep 21 16:08:57 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: rtld.c,v 1.205 2020/04/19 01:06:15 joerg Exp $ */
+/* $NetBSD: rtld.c,v 1.206 2020/09/21 16:08:57 kamil Exp $ */
/*
* Copyright 1996 John D. Polstra.
@@ -40,7 +40,7 @@
#include <sys/cdefs.h>
#ifndef lint
-__RCSID("$NetBSD: rtld.c,v 1.205 2020/04/19 01:06:15 joerg Exp $");
+__RCSID("$NetBSD: rtld.c,v 1.206 2020/09/21 16:08:57 kamil Exp $");
#endif /* not lint */
#include <sys/param.h>
@@ -81,7 +81,7 @@ Elf_Addr _rtld(Elf_Addr *, Elf_Ad
*/
static char *error_message; /* Message for dlopen(), or NULL */
-struct r_debug _rtld_debug; /* for GDB; */
+struct r_debug _rtld_debug; /* The SVR4 interface for the debugger */
bool _rtld_trust; /* False for setuid and setgid programs */
Obj_Entry *_rtld_objlist; /* Head of linked list of shared objects */
Obj_Entry **_rtld_objtail; /* Link field of last object in list */
@@ -394,8 +394,10 @@ _rtld_init(caddr_t mapbase, caddr_t relo
_rtld_objtail = &_rtld_objlist;
_rtld_objcount = 0;
+ _rtld_debug.r_version = R_DEBUG_VERSION;
_rtld_debug.r_brk = _rtld_debug_state;
_rtld_debug.r_state = RT_CONSISTENT;
+ _rtld_debug.r_ldbase = &_rtld_objself.linkmap;
ehdr = (Elf_Ehdr *)mapbase;
_rtld_objself.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff);
@@ -676,8 +678,8 @@ _rtld(Elf_Addr *sp, Elf_Addr relocbase)
/*
* Get the actual dynamic linker pathname from the executable if
* possible. (It should always be possible.) That ensures that
- * gdb will find the right dynamic linker even if a non-standard
- * one is being used.
+ * the debugger will find the right dynamic linker even if a
+ * non-standard one is being used.
*/
if (_rtld_objmain->interp != NULL &&
strcmp(_rtld_objmain->interp, _rtld_objself.path) != 0) {
@@ -774,7 +776,7 @@ _rtld(Elf_Addr *sp, Elf_Addr relocbase)
if (real___mainprog_obj)
*real___mainprog_obj = _rtld_objmain;
- _rtld_debug_state(); /* say hello to gdb! */
+ _rtld_debug_state(); /* say hello to the debugger! */
_rtld_exclusive_enter(&mask);
Index: src/libexec/ld.elf_so/rtld.h
diff -u src/libexec/ld.elf_so/rtld.h:1.140 src/libexec/ld.elf_so/rtld.h:1.141
--- src/libexec/ld.elf_so/rtld.h:1.140 Sun Apr 19 01:06:15 2020
+++ src/libexec/ld.elf_so/rtld.h Mon Sep 21 16:08:57 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: rtld.h,v 1.140 2020/04/19 01:06:15 joerg Exp $ */
+/* $NetBSD: rtld.h,v 1.141 2020/09/21 16:08:57 kamil Exp $ */
/*
* Copyright 1996 John D. Polstra.
@@ -226,7 +226,7 @@ typedef struct Struct_Obj_Entry {
sysv_hash:1, /* SysV Hash available */
gnu_hash:1; /* GNU Hash available */
- struct link_map linkmap; /* for GDB */
+ struct link_map linkmap; /* for the debugger */
/* These items are computed by map_object() or by digest_phdr(). */
const char *interp; /* Pathname of the interpreter, if any */
