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-rw-r--r--elf/rtld.c362
1 files changed, 200 insertions, 162 deletions
diff --git a/elf/rtld.c b/elf/rtld.c
index 44361ba605..c1cc1b01f2 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -866,6 +866,205 @@ handle_preload_list (const char *preloadlist, struct link_map *main_map,
return npreloads;
}
+/* Called if the audit DSO cannot be used: if it does not have the
+ appropriate interfaces, or it expects a more recent version library
+ version than what the dynamic linker provides. */
+static void
+unload_audit_module (struct link_map *map, int original_tls_idx)
+{
+#ifndef NDEBUG
+ Lmid_t ns = map->l_ns;
+#endif
+ _dl_close (map);
+
+ /* Make sure the namespace has been cleared entirely. */
+ assert (GL(dl_ns)[ns]._ns_loaded == NULL);
+ assert (GL(dl_ns)[ns]._ns_nloaded == 0);
+
+ GL(dl_tls_max_dtv_idx) = original_tls_idx;
+}
+
+/* Called to print an error message if loading of an audit module
+ failed. */
+static void
+report_audit_module_load_error (const char *name, const char *err_str,
+ bool malloced)
+{
+ _dl_error_printf ("\
+ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
+ name, err_str);
+ if (malloced)
+ free ((char *) err_str);
+}
+
+/* Load one audit module. */
+static void
+load_audit_module (const char *name, struct audit_ifaces **last_audit)
+{
+ int original_tls_idx = GL(dl_tls_max_dtv_idx);
+
+ struct dlmopen_args dlmargs;
+ dlmargs.fname = name;
+ dlmargs.map = NULL;
+
+ const char *objname;
+ const char *err_str = NULL;
+ bool malloced;
+ _dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit, &dlmargs);
+ if (__glibc_unlikely (err_str != NULL))
+ {
+ report_audit_module_load_error (name, err_str, malloced);
+ return;
+ }
+
+ struct lookup_args largs;
+ largs.name = "la_version";
+ largs.map = dlmargs.map;
+ _dl_catch_error (&objname, &err_str, &malloced, lookup_doit, &largs);
+ if (__glibc_likely (err_str != NULL))
+ {
+ unload_audit_module (dlmargs.map, original_tls_idx);
+ report_audit_module_load_error (name, err_str, malloced);
+ return;
+ }
+
+ unsigned int (*laversion) (unsigned int) = largs.result;
+
+ /* A null symbol indicates that something is very wrong with the
+ loaded object because defined symbols are supposed to have a
+ valid, non-null address. */
+ assert (laversion != NULL);
+
+ unsigned int lav = laversion (LAV_CURRENT);
+ if (lav == 0)
+ {
+ /* Only print an error message if debugging because this can
+ happen deliberately. */
+ if (GLRO(dl_debug_mask) & DL_DEBUG_FILES)
+ _dl_debug_printf ("\
+file=%s [%lu]; audit interface function la_version returned zero; ignored.\n",
+ dlmargs.map->l_name, dlmargs.map->l_ns);
+ unload_audit_module (dlmargs.map, original_tls_idx);
+ return;
+ }
+
+ if (lav > LAV_CURRENT)
+ {
+ _dl_debug_printf ("\
+ERROR: audit interface '%s' requires version %d (maximum supported version %d); ignored.\n",
+ name, lav, LAV_CURRENT);
+ unload_audit_module (dlmargs.map, original_tls_idx);
+ return;
+ }
+
+ enum { naudit_ifaces = 8 };
+ union
+ {
+ struct audit_ifaces ifaces;
+ void (*fptr[naudit_ifaces]) (void);
+ } *newp = malloc (sizeof (*newp));
+ if (newp == NULL)
+ _dl_fatal_printf ("Out of memory while loading audit modules\n");
+
+ /* Names of the auditing interfaces. All in one
+ long string. */
+ static const char audit_iface_names[] =
+ "la_activity\0"
+ "la_objsearch\0"
+ "la_objopen\0"
+ "la_preinit\0"
+#if __ELF_NATIVE_CLASS == 32
+ "la_symbind32\0"
+#elif __ELF_NATIVE_CLASS == 64
+ "la_symbind64\0"
+#else
+# error "__ELF_NATIVE_CLASS must be defined"
+#endif
+#define STRING(s) __STRING (s)
+ "la_" STRING (ARCH_LA_PLTENTER) "\0"
+ "la_" STRING (ARCH_LA_PLTEXIT) "\0"
+ "la_objclose\0";
+ unsigned int cnt = 0;
+ const char *cp = audit_iface_names;
+ do
+ {
+ largs.name = cp;
+ _dl_catch_error (&objname, &err_str, &malloced, lookup_doit, &largs);
+
+ /* Store the pointer. */
+ if (err_str == NULL && largs.result != NULL)
+ {
+ newp->fptr[cnt] = largs.result;
+
+ /* The dynamic linker link map is statically allocated,
+ initialize the data now. */
+ GL(dl_rtld_map).l_audit[cnt].cookie = (intptr_t) &GL(dl_rtld_map);
+ }
+ else
+ newp->fptr[cnt] = NULL;
+ ++cnt;
+
+ cp = rawmemchr (cp, '\0') + 1;
+ }
+ while (*cp != '\0');
+ assert (cnt == naudit_ifaces);
+
+ /* Now append the new auditing interface to the list. */
+ newp->ifaces.next = NULL;
+ if (*last_audit == NULL)
+ *last_audit = GLRO(dl_audit) = &newp->ifaces;
+ else
+ *last_audit = (*last_audit)->next = &newp->ifaces;
+ ++GLRO(dl_naudit);
+
+ /* Mark the DSO as being used for auditing. */
+ dlmargs.map->l_auditing = 1;
+}
+
+/* Notify the the audit modules that the object MAP has already been
+ loaded. */
+static void
+notify_audit_modules_of_loaded_object (struct link_map *map)
+{
+ struct audit_ifaces *afct = GLRO(dl_audit);
+ for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
+ {
+ if (afct->objopen != NULL)
+ {
+ map->l_audit[cnt].bindflags
+ = afct->objopen (map, LM_ID_BASE, &map->l_audit[cnt].cookie);
+ map->l_audit_any_plt |= map->l_audit[cnt].bindflags != 0;
+ }
+
+ afct = afct->next;
+ }
+}
+
+/* Load all audit modules. */
+static void
+load_audit_modules (struct link_map *main_map)
+{
+ struct audit_ifaces *last_audit = NULL;
+ struct audit_list_iter al_iter;
+ audit_list_iter_init (&al_iter);
+
+ while (true)
+ {
+ const char *name = audit_list_iter_next (&al_iter);
+ if (name == NULL)
+ break;
+ load_audit_module (name, &last_audit);
+ }
+
+ /* Notify audit modules of the initially loaded modules (the main
+ program and the dynamic linker itself). */
+ if (GLRO(dl_naudit) > 0)
+ {
+ notify_audit_modules_of_loaded_object (main_map);
+ notify_audit_modules_of_loaded_object (&GL(dl_rtld_map));
+ }
+}
+
static void
dl_main (const ElfW(Phdr) *phdr,
ElfW(Word) phnum,
@@ -1406,10 +1605,6 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]);
if (__glibc_unlikely (audit_list != NULL)
|| __glibc_unlikely (audit_list_string != NULL))
{
- struct audit_ifaces *last_audit = NULL;
- struct audit_list_iter al_iter;
- audit_list_iter_init (&al_iter);
-
/* Since we start using the auditing DSOs right away we need to
initialize the data structures now. */
tcbp = init_tls ();
@@ -1421,164 +1616,7 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]);
security_init ();
need_security_init = false;
- while (true)
- {
- const char *name = audit_list_iter_next (&al_iter);
- if (name == NULL)
- break;
-
- int tls_idx = GL(dl_tls_max_dtv_idx);
-
- /* Now it is time to determine the layout of the static TLS
- block and allocate it for the initial thread. Note that we
- always allocate the static block, we never defer it even if
- no DF_STATIC_TLS bit is set. The reason is that we know
- glibc will use the static model. */
- struct dlmopen_args dlmargs;
- dlmargs.fname = name;
- dlmargs.map = NULL;
-
- const char *objname;
- const char *err_str = NULL;
- bool malloced;
- (void) _dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit,
- &dlmargs);
- if (__glibc_unlikely (err_str != NULL))
- {
- not_loaded:
- _dl_error_printf ("\
-ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
- name, err_str);
- if (malloced)
- free ((char *) err_str);
- }
- else
- {
- struct lookup_args largs;
- largs.name = "la_version";
- largs.map = dlmargs.map;
-
- /* Check whether the interface version matches. */
- (void) _dl_catch_error (&objname, &err_str, &malloced,
- lookup_doit, &largs);
-
- unsigned int (*laversion) (unsigned int);
- unsigned int lav;
- if (err_str == NULL
- && (laversion = largs.result) != NULL
- && (lav = laversion (LAV_CURRENT)) > 0
- && lav <= LAV_CURRENT)
- {
- /* Allocate structure for the callback function pointers.
- This call can never fail. */
- union
- {
- struct audit_ifaces ifaces;
-#define naudit_ifaces 8
- void (*fptr[naudit_ifaces]) (void);
- } *newp = malloc (sizeof (*newp));
-
- /* Names of the auditing interfaces. All in one
- long string. */
- static const char audit_iface_names[] =
- "la_activity\0"
- "la_objsearch\0"
- "la_objopen\0"
- "la_preinit\0"
-#if __ELF_NATIVE_CLASS == 32
- "la_symbind32\0"
-#elif __ELF_NATIVE_CLASS == 64
- "la_symbind64\0"
-#else
-# error "__ELF_NATIVE_CLASS must be defined"
-#endif
-#define STRING(s) __STRING (s)
- "la_" STRING (ARCH_LA_PLTENTER) "\0"
- "la_" STRING (ARCH_LA_PLTEXIT) "\0"
- "la_objclose\0";
- unsigned int cnt = 0;
- const char *cp = audit_iface_names;
- do
- {
- largs.name = cp;
- (void) _dl_catch_error (&objname, &err_str, &malloced,
- lookup_doit, &largs);
-
- /* Store the pointer. */
- if (err_str == NULL && largs.result != NULL)
- {
- newp->fptr[cnt] = largs.result;
-
- /* The dynamic linker link map is statically
- allocated, initialize the data now. */
- GL(dl_rtld_map).l_audit[cnt].cookie
- = (intptr_t) &GL(dl_rtld_map);
- }
- else
- newp->fptr[cnt] = NULL;
- ++cnt;
-
- cp = (char *) rawmemchr (cp, '\0') + 1;
- }
- while (*cp != '\0');
- assert (cnt == naudit_ifaces);
-
- /* Now append the new auditing interface to the list. */
- newp->ifaces.next = NULL;
- if (last_audit == NULL)
- last_audit = GLRO(dl_audit) = &newp->ifaces;
- else
- last_audit = last_audit->next = &newp->ifaces;
- ++GLRO(dl_naudit);
-
- /* Mark the DSO as being used for auditing. */
- dlmargs.map->l_auditing = 1;
- }
- else
- {
- /* We cannot use the DSO, it does not have the
- appropriate interfaces or it expects something
- more recent. */
-#ifndef NDEBUG
- Lmid_t ns = dlmargs.map->l_ns;
-#endif
- _dl_close (dlmargs.map);
-
- /* Make sure the namespace has been cleared entirely. */
- assert (GL(dl_ns)[ns]._ns_loaded == NULL);
- assert (GL(dl_ns)[ns]._ns_nloaded == 0);
-
- GL(dl_tls_max_dtv_idx) = tls_idx;
- goto not_loaded;
- }
- }
- }
-
- /* If we have any auditing modules, announce that we already
- have two objects loaded. */
- if (__glibc_unlikely (GLRO(dl_naudit) > 0))
- {
- struct link_map *ls[2] = { main_map, &GL(dl_rtld_map) };
-
- for (unsigned int outer = 0; outer < 2; ++outer)
- {
- struct audit_ifaces *afct = GLRO(dl_audit);
- for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
- {
- if (afct->objopen != NULL)
- {
- ls[outer]->l_audit[cnt].bindflags
- = afct->objopen (ls[outer], LM_ID_BASE,
- &ls[outer]->l_audit[cnt].cookie);
-
- ls[outer]->l_audit_any_plt
- |= ls[outer]->l_audit[cnt].bindflags != 0;
- }
-
- afct = afct->next;
- }
- }
- }
+ load_audit_modules (main_map);
}
/* Keep track of the currently loaded modules to count how many
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-13 14:03:57 +0000