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-rw-r--r--elf/Makefile2
-rw-r--r--elf/dl-load.c86
-rw-r--r--elf/dl-support.c1
-rw-r--r--elf/genrtldtbl.awk2
-rw-r--r--elf/link.h11
-rw-r--r--elf/rtld.c50
6 files changed, 143 insertions, 9 deletions
diff --git a/elf/Makefile b/elf/Makefile
index aff64e4b9f..fc74fa4c8e 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -142,7 +142,7 @@ $(objpfx)trusted-dirs.h: Makefile
echo " \"$$dir\","; \
done;) > $@T
mv -f $@T $@
-$(objpfx)rtldtbl.h: Makefile
+$(objpfx)rtldtbl.h: Makefile genrtldtbl.awk
$(make-target-directory)
echo "$(default-rpath)" | awk -f genrtldtbl.awk > $@T
mv -f $@T $@
diff --git a/elf/dl-load.c b/elf/dl-load.c
index 7adb6612d0..003754bf60 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -92,6 +92,9 @@ ELF_PREFERRED_ADDRESS_DATA;
size_t _dl_pagesize;
+/* Arguments passed to the dynamic linker. */
+extern char **_dl_argv;
+
extern const char *_dl_platform;
extern size_t _dl_platformlen;
@@ -163,7 +166,7 @@ static size_t max_dirnamelen;
static inline struct r_search_path_elem **
fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
- const char **trusted)
+ const char **trusted, const char *what, const char *where)
{
char *cp;
size_t nelems = 0;
@@ -268,6 +271,9 @@ fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
max_dirnamelen = dirp->dirnamelen;
}
+ dirp->what = what;
+ dirp->where = where;
+
dirp->next = all_dirs;
all_dirs = dirp;
@@ -284,7 +290,8 @@ fillin_rpath (char *rpath, struct r_search_path_elem **result, const char *sep,
static struct r_search_path_elem **
-decompose_rpath (const char *rpath, size_t additional_room)
+decompose_rpath (const char *rpath, size_t additional_room,
+ const char *what, const char *where)
{
/* Make a copy we can work with. */
char *copy = strdupa (rpath);
@@ -305,7 +312,7 @@ decompose_rpath (const char *rpath, size_t additional_room)
if (result == NULL)
_dl_signal_error (ENOMEM, NULL, "cannot create cache for search path");
- return fillin_rpath (copy, result, ":", NULL);
+ return fillin_rpath (copy, result, ":", NULL, what, where);
}
@@ -358,7 +365,7 @@ _dl_init_paths (const char *llp)
decompose_rpath ((const char *)
(l->l_addr + l->l_info[DT_STRTAB]->d_un.d_ptr
+ l->l_info[DT_RPATH]->d_un.d_val),
- nllp);
+ nllp, "RPATH", l->l_name);
}
else
{
@@ -394,7 +401,8 @@ _dl_init_paths (const char *llp)
/* We need to take care that the LD_LIBRARY_PATH environment
variable can contain a semicolon. */
(void) fillin_rpath (copy, result, ":;",
- __libc_enable_secure ? trusted_dirs : NULL);
+ __libc_enable_secure ? trusted_dirs : NULL,
+ "LD_LIBRARY_PATH", NULL);
}
}
else
@@ -415,7 +423,8 @@ _dl_init_paths (const char *llp)
"cannot create cache for search path");
(void) fillin_rpath (local_strdup (llp), fake_path_list, ":;",
- __libc_enable_secure ? trusted_dirs : NULL);
+ __libc_enable_secure ? trusted_dirs : NULL,
+ "LD_LIBRARY_PATH", NULL);
}
}
@@ -454,6 +463,9 @@ _dl_init_paths (const char *llp)
if (max_dirnamelen < relem->dirnamelen)
max_dirnamelen = relem->dirnamelen;
}
+
+ relem->what = "system search path";
+ relem->where = NULL;
}
}
@@ -789,6 +801,41 @@ _dl_map_object_from_fd (char *name, int fd, char *realname,
return l;
}
+/* Print search path. */
+static void
+print_search_path (struct r_search_path_elem **list,
+ const char *what, const char *name)
+{
+ int first = 1;
+
+ _dl_sysdep_message ("\t search path=", NULL);
+
+ while (*list != NULL && (*list)->what == what) /* Yes, ==. */
+ {
+ char *buf = strdupa ((*list)->dirname);
+
+ if ((*list)->machdirstatus != nonexisting)
+ {
+ buf[(*list)->machdirnamelen - 1] = '\0';
+ _dl_sysdep_message (first ? "" : ":", buf, NULL);
+ first = 0;
+ }
+ if ((*list)->dirstatus != nonexisting)
+ {
+ buf[(*list)->dirnamelen - 1] = '\0';
+ _dl_sysdep_message (first ? "" : ":", buf, NULL);
+ first = 0;
+ }
+ ++list;
+ }
+
+ if (name != NULL)
+ _dl_sysdep_message ("\t\t(", what, " from file ",
+ name[0] ? name : _dl_argv[0], ")\n", NULL);
+ else
+ _dl_sysdep_message ("\t\t(", what, ")\n", NULL);
+}
+
/* Try to open NAME in one of the directories in DIRS.
Return the fd, or -1. If successful, fill in *REALNAME
with the malloc'd full directory name. */
@@ -800,6 +847,7 @@ open_path (const char *name, size_t namelen, int preloaded,
{
char *buf;
int fd = -1;
+ const char *current_what = NULL;
if (dirs == NULL || *dirs == NULL)
{
@@ -813,6 +861,14 @@ open_path (const char *name, size_t namelen, int preloaded,
struct r_search_path_elem *this_dir = *dirs;
size_t buflen = 0;
+ /* If we are debugging the search for libraries print the path
+ now if it hasn't happened now. */
+ if (_dl_debug_libs && current_what != this_dir->what)
+ {
+ current_what = this_dir->what;
+ print_search_path (dirs, current_what, this_dir->where);
+ }
+
if (this_dir->machdirstatus != nonexisting)
{
/* Construct the pathname to try. */
@@ -821,6 +877,10 @@ open_path (const char *name, size_t namelen, int preloaded,
name, namelen)
- buf);
+ /* Print name we try if this is wanted. */
+ if (_dl_debug_libs)
+ _dl_sysdep_message ("\t trying file=", buf, "\n", NULL);
+
fd = __open (buf, O_RDONLY);
if (this_dir->machdirstatus == unknown)
if (fd != -1)
@@ -872,6 +932,10 @@ open_path (const char *name, size_t namelen, int preloaded,
name, namelen)
- buf);
+ /* Print name we try if this is wanted. */
+ if (_dl_debug_libs)
+ _dl_sysdep_message ("\t trying file=", buf, "\n", NULL);
+
fd = __open (buf, O_RDONLY);
if (this_dir->dirstatus == unknown)
if (fd != -1)
@@ -988,6 +1052,9 @@ _dl_map_object (struct link_map *loader, const char *name, int preloaded,
size_t namelen = strlen (name) + 1;
+ if (_dl_debug_libs)
+ _dl_sysdep_message ("\tfind library=", name, "; searching\n", NULL);
+
fd = -1;
/* First try the DT_RPATH of the dependent object that caused NAME
@@ -1002,7 +1069,8 @@ _dl_map_object (struct link_map *loader, const char *name, int preloaded,
+ l->l_info[DT_STRTAB]->d_un.d_ptr
+ l->l_info[DT_RPATH]->d_un.d_val);
l->l_rpath_dirs =
- decompose_rpath ((const char *) ptrval, 0);
+ decompose_rpath ((const char *) ptrval, 0,
+ "RPATH", l->l_name);
}
if (l->l_rpath_dirs != (struct r_search_path_elem **) -1l)
@@ -1046,6 +1114,10 @@ _dl_map_object (struct link_map *loader, const char *name, int preloaded,
/* Finally, try the default path. */
if (fd == -1)
fd = open_path (name, namelen, preloaded, rtld_search_dirs, &realname);
+
+ /* Add another newline when we a tracing the library loading. */
+ if (_dl_debug_libs)
+ _dl_sysdep_message ("\n", NULL);
}
else
{
diff --git a/elf/dl-support.c b/elf/dl-support.c
index 5868656c4e..9d28d2b640 100644
--- a/elf/dl-support.c
+++ b/elf/dl-support.c
@@ -35,6 +35,7 @@ const char *_dl_rpath = DEFAULT_RPATH;
/* Name of the architecture. */
const char *_dl_platform;
size_t _dl_platformlen;
+int _dl_debug_libs;
/* If nonzero print warnings about problematic situations. */
int _dl_verbose;
diff --git a/elf/genrtldtbl.awk b/elf/genrtldtbl.awk
index 63ada003f6..54cdc8c589 100644
--- a/elf/genrtldtbl.awk
+++ b/elf/genrtldtbl.awk
@@ -12,7 +12,7 @@ BEGIN {
END {
for (i = 0; i < count; ++i) {
printf ("static struct r_search_path_elem rtld_search_dir%d =\n", i+1);
- printf (" { \"%s/\", %d, unknown, 0, nonexisting, ",
+ printf (" { \"%s/\", %d, unknown, 0, nonexisting, NULL, NULL, ",
dir[i], length (dir[i]) + 1);
if (i== 0)
printf ("NULL };\n");
diff --git a/elf/link.h b/elf/link.h
index d056e65617..b8bce5839d 100644
--- a/elf/link.h
+++ b/elf/link.h
@@ -106,6 +106,10 @@ struct r_search_path_elem
size_t machdirnamelen;
enum r_dir_status machdirstatus;
+ /* Strings saying where the definition came from. */
+ const char *what;
+ const char *where;
+
/* This link is only used in the `all_dirs' member of `r_search_path'. */
struct r_search_path_elem *next;
};
@@ -238,6 +242,9 @@ extern const char *_dl_profile;
/* Map of shared object to be profiled. */
extern struct link_map *_dl_profile_map;
+/* If nonzero the appropriate debug information if printed. */
+extern int _dl_debug_libs;
+
/* OS-dependent function to open the zero-fill device. */
extern int _dl_sysdep_open_zero_fill (void); /* dl-sysdep.c */
@@ -461,6 +468,10 @@ extern void _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc);
/* Show the members of the auxiliary array passed up from the kernel. */
extern void _dl_show_auxv (void);
+/* Return all environment variables starting with `LD_', one after the
+ other. */
+extern char *_dl_next_ld_env_entry (char ***position);
+
__END_DECLS
#endif /* link.h */
diff --git a/elf/rtld.c b/elf/rtld.c
index 2707da60df..72316905b4 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -73,6 +73,7 @@ struct r_search_path *_dl_search_paths;
const char *_dl_profile;
const char *_dl_profile_output;
struct link_map *_dl_profile_map;
+int _dl_debug_libs;
/* Set nonzero during loading and initialization of executable and
libraries, cleared before the executable's entry point runs. This
@@ -906,6 +907,45 @@ print_missing_version (int errcode __attribute__ ((unused)),
objname, ": ", errstring, "\n", NULL);
}
+/* Process the string given as the parameter which explains which debugging
+ options are enabled. */
+static void
+process_dl_debug (char *dl_debug)
+{
+ do
+ {
+#define issep(Ch) ((Ch) == ' ' || (Ch) == ',')
+ /* Skip separating white spaces and commas. */
+ while (issep (*dl_debug))
+ ++dl_debug;
+ if (*dl_debug != '\0')
+ {
+ if (strncmp (dl_debug, "libs", 4) == 0
+ && (issep (dl_debug[4]) || dl_debug[4] == '\0'))
+ {
+ _dl_debug_libs = 1;
+ dl_debug += 4;
+ }
+ else if (strncmp (dl_debug, "help", 4) == 0
+ && (issep (dl_debug[4]) || dl_debug[4] == '\0'))
+ {
+ _dl_sysdep_message ("\
+Valid options for the DL_DEBUG environment variable are:\n\
+\n\
+ help display this help message and exit
+ libs display library search paths\n", NULL);
+ _exit (0);
+ }
+ else
+ /* Skip everything until next separator. */
+ do
+ ++dl_debug;
+ while (*dl_debug != '\0' && !issep (*dl_debug));
+ }
+ }
+ while (*dl_debug != '\0');
+}
+
/* Process all environments variables the dynamic linker must recognize.
Since all of them start with `LD_' we are a bit smarter while finding
all the entries. */
@@ -934,6 +974,16 @@ process_envvars (enum mode *modep, int *lazyp)
if (result < 0)
continue;
+ /* Debugging of the dynamic linker? */
+ result = strncmp (&envline[3], "DEBUG=", 6);
+ if (result == 0)
+ {
+ process_dl_debug (&envline[9]);
+ continue;
+ }
+ if (result < 0)
+ continue;
+
/* Which shared object shall be profiled. */
result = strncmp (&envline[3], "PROFILE=", 8);
if (result == 0)