svn commit: r190543 - in head: include libexec/rtld-elf sys/sys

[Robert Noland]

On Mon, 2009-03-30 at 08:47 +0000, Konstantin Belousov wrote:
> Author: kib
> Date: Mon Mar 30 08:47:28 2009
> New Revision: 190543
> URL: http://svn.freebsd.org/changeset/base/190543
> 
> Log:
>   Implement support for RTLD_NODELETE flag for dlopen() and -z nodelete
>   static linker option. Do it by incrementing reference count on the loaded
>   object and its dependencies.

Cool, I can drop my patches to compiz now.

robert.

>   Reviewed by:	davidxu, kan
> 
> Modified:
>   head/include/dlfcn.h
>   head/libexec/rtld-elf/rtld.c
>   head/libexec/rtld-elf/rtld.h
>   head/sys/sys/elf_common.h
> 
> Modified: head/include/dlfcn.h
> ==============================================================================
> --- head/include/dlfcn.h	Mon Mar 30 08:44:29 2009	(r190542)
> +++ head/include/dlfcn.h	Mon Mar 30 08:47:28 2009	(r190543)
> @@ -47,6 +47,7 @@
>  #define	RTLD_GLOBAL	0x100	/* Make symbols globally available. */
>  #define	RTLD_LOCAL	0	/* Opposite of RTLD_GLOBAL, and the default. */
>  #define	RTLD_TRACE	0x200	/* Trace loaded objects and exit. */
> +#define	RTLD_NODELETE	0x01000	/* Do not remove members. */
>  
>  /*
>   * Request arguments for dlinfo().
> 
> Modified: head/libexec/rtld-elf/rtld.c
> ==============================================================================
> --- head/libexec/rtld-elf/rtld.c	Mon Mar 30 08:44:29 2009	(r190542)
> +++ head/libexec/rtld-elf/rtld.c	Mon Mar 30 08:47:28 2009	(r190543)
> @@ -937,6 +937,8 @@ digest_dynamic(Obj_Entry *obj, int early
>  			/* XXX */;
>  		if (dynp->d_un.d_val & DF_1_BIND_NOW)
>  		    obj->bind_now = true;
> +		if (dynp->d_un.d_val & DF_1_NODELETE)
> +		    obj->z_nodelete = true;
>  	    break;
>  
>  	default:
> @@ -1422,15 +1424,21 @@ is_exported(const Elf_Sym *def)
>  static int
>  load_needed_objects(Obj_Entry *first)
>  {
> -    Obj_Entry *obj;
> +    Obj_Entry *obj, *obj1;
>  
>      for (obj = first;  obj != NULL;  obj = obj->next) {
>  	Needed_Entry *needed;
>  
>  	for (needed = obj->needed;  needed != NULL;  needed = needed->next) {
> -	    needed->obj = load_object(obj->strtab + needed->name, obj);
> -	    if (needed->obj == NULL && !ld_tracing)
> +	    obj1 = needed->obj = load_object(obj->strtab + needed->name, obj);
> +	    if (obj1 == NULL && !ld_tracing)
>  		return -1;
> +	    if (obj1 != NULL && obj1->z_nodelete && !obj1->ref_nodel) {
> +		dbg("obj %s nodelete", obj1->path);
> +		init_dag(obj1);
> +		ref_dag(obj1);
> +		obj1->ref_nodel = true;
> +	    }
>  	}
>      }
>  
> @@ -1976,12 +1984,13 @@ dlopen(const char *name, int mode)
>      Obj_Entry **old_obj_tail;
>      Obj_Entry *obj;
>      Objlist initlist;
> -    int result, lockstate;
> +    int result, lockstate, nodelete;
>  
>      LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name);
>      ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
>      if (ld_tracing != NULL)
>  	environ = (char **)*get_program_var_addr("environ");
> +    nodelete = mode & RTLD_NODELETE;
>  
>      objlist_init(&initlist);
>  
> @@ -2029,6 +2038,11 @@ dlopen(const char *name, int mode)
>  	    if (ld_tracing)
>  		goto trace;
>  	}
> +	if (obj != NULL && (nodelete || obj->z_nodelete) && !obj->ref_nodel) {
> +	    dbg("obj %s nodelete", obj->path);
> +	    ref_dag(obj);
> +	    obj->z_nodelete = obj->ref_nodel = true;
> +	}
>      }
>  
>      LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0,
> 
> Modified: head/libexec/rtld-elf/rtld.h
> ==============================================================================
> --- head/libexec/rtld-elf/rtld.h	Mon Mar 30 08:44:29 2009	(r190542)
> +++ head/libexec/rtld-elf/rtld.h	Mon Mar 30 08:47:28 2009	(r190543)
> @@ -217,6 +217,8 @@ typedef struct Struct_Obj_Entry {
>      bool tls_done : 1;		/* Already allocated offset for static TLS */
>      bool phdr_alloc : 1;	/* Phdr is allocated and needs to be freed. */
>      bool z_origin : 1;		/* Process rpath and soname tokens */
> +    bool z_nodelete : 1;	/* Do not unload the object and dependencies */
> +    bool ref_nodel : 1;		/* refcount increased to prevent dlclose */
>  
>      struct link_map linkmap;	/* for GDB and dlinfo() */
>      Objlist dldags;		/* Object belongs to these dlopened DAGs (%) */
> 
> Modified: head/sys/sys/elf_common.h
> ==============================================================================
> --- head/sys/sys/elf_common.h	Mon Mar 30 08:44:29 2009	(r190542)
> +++ head/sys/sys/elf_common.h	Mon Mar 30 08:47:28 2009	(r190543)
> @@ -469,6 +469,7 @@ typedef struct {
>  /* Values for DT_FLAGS_1 */
>  #define	DF_1_BIND_NOW	0x00000001	/* Same as DF_BIND_NOW */
>  #define	DF_1_GLOBAL	0x00000002	/* Set the RTLD_GLOBAL for object */
> +#define	DF_1_NODELETE	0x00000008	/* Set the RTLD_NODELETE for object */
>  #define	DF_1_ORIGIN	0x00000080	/* Process $ORIGIN */
>  
>  /* Values for n_type.  Used in core files. */
-- 
Robert Noland <rnoland at FreeBSD.org>
FreeBSD
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