Introduce link_map_audit_state accessor function

To improve GCC 10 compatibility, it is necessary to remove the l_audit
zero-length array from the end of struct link_map.  In preparation of
that, this commit introduces an accessor function for the audit state,
so that it is possible to change the representation of the audit state
without adjusting the code that accesses it.

Tested on x86_64-linux-gnu.  Built on i686-gnu.

Change-Id: Id815673c29950fc011ae5301d7cde12624f658df

10 files changed, 78 insertions, 45 deletions

diff --git a/csu/libc-start.c b/csu/libc-start.c
index 14e2b693f0..e9e8e44fe5 100644
--- a/csu/libc-start.c
+++ b/csu/libc-start.c
@@ -272,7 +272,7 @@ LIBC_START_MAIN (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL),
       for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
 	{
 	  if (afct->preinit != NULL)
-	    afct->preinit (&head->l_audit[cnt].cookie);
+	    afct->preinit (&link_map_audit_state (head, cnt)->cookie);
 
 	  afct = afct->next;
 	}
diff --git a/elf/dl-close.c b/elf/dl-close.c
index de91c28f72..c32e6473ad 100644
--- a/elf/dl-close.c
+++ b/elf/dl-close.c
@@ -302,8 +302,12 @@ _dl_close_worker (struct link_map *map, bool force)
 	      for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
 		{
 		  if (afct->objclose != NULL)
-		    /* Return value is ignored.  */
-		    (void) afct->objclose (&imap->l_audit[cnt].cookie);
+		    {
+		      struct auditstate *state
+			= link_map_audit_state (imap, cnt);
+		      /* Return value is ignored.  */
+		      (void) afct->objclose (&state->cookie);
+		    }
 
 		  afct = afct->next;
 		}
@@ -478,7 +482,10 @@ _dl_close_worker (struct link_map *map, bool force)
 	  for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
 	    {
 	      if (afct->activity != NULL)
-		afct->activity (&head->l_audit[cnt].cookie, LA_ACT_DELETE);
+		{
+		  struct auditstate *state = link_map_audit_state (head, cnt);
+		  afct->activity (&state->cookie, LA_ACT_DELETE);
+		}
 
 	      afct = afct->next;
 	    }
@@ -774,7 +781,10 @@ _dl_close_worker (struct link_map *map, bool force)
 	  for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
 	    {
 	      if (afct->activity != NULL)
-		afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT);
+		{
+		  struct auditstate *state = link_map_audit_state (head, cnt);
+		  afct->activity (&state->cookie, LA_ACT_CONSISTENT);
+		}
 
 	      afct = afct->next;
 	    }
diff --git a/elf/dl-fini.c b/elf/dl-fini.c
index bed736d756..70e7346304 100644
--- a/elf/dl-fini.c
+++ b/elf/dl-fini.c
@@ -152,9 +152,12 @@ _dl_fini (void)
 		      for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
 			{
 			  if (afct->objclose != NULL)
-			    /* Return value is ignored.  */
-			    (void) afct->objclose (&l->l_audit[cnt].cookie);
-
+			    {
+			      struct auditstate *state
+				= link_map_audit_state (l, cnt);
+			      /* Return value is ignored.  */
+			      (void) afct->objclose (&state->cookie);
+			    }
 			  afct = afct->next;
 			}
 		    }
diff --git a/elf/dl-load.c b/elf/dl-load.c
index c1bc8c26be..6cdd11e6b0 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -973,7 +973,8 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd,
 	      for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
 		{
 		  if (afct->activity != NULL)
-		    afct->activity (&head->l_audit[cnt].cookie, LA_ACT_ADD);
+		    afct->activity (&link_map_audit_state (head, cnt)->cookie,
+				    LA_ACT_ADD);
 
 		  afct = afct->next;
 		}
@@ -1402,10 +1403,9 @@ cannot enable executable stack as shared object requires");
 	{
 	  if (afct->objopen != NULL)
 	    {
-	      l->l_audit[cnt].bindflags
-		= afct->objopen (l, nsid, &l->l_audit[cnt].cookie);
-
-	      l->l_audit_any_plt |= l->l_audit[cnt].bindflags != 0;
+	      struct auditstate *state = link_map_audit_state (l, cnt);
+	      state->bindflags = afct->objopen (l, nsid, &state->cookie);
+	      l->l_audit_any_plt |= state->bindflags != 0;
 	    }
 
 	  afct = afct->next;
@@ -1511,8 +1511,8 @@ open_verify (const char *name, int fd,
 	{
 	  if (afct->objsearch != NULL)
 	    {
-	      name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
-				      whatcode);
+	      struct auditstate *state = link_map_audit_state (loader, cnt);
+	      name = afct->objsearch (name, &state->cookie, whatcode);
 	      if (name == NULL)
 		/* Ignore the path.  */
 		return -1;
@@ -1970,8 +1970,8 @@ _dl_map_object (struct link_map *loader, const char *name,
 	  if (afct->objsearch != NULL)
 	    {
 	      const char *before = name;
-	      name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
-				      LA_SER_ORIG);
+	      struct auditstate *state = link_map_audit_state (loader, cnt);
+	      name = afct->objsearch (name, &state->cookie, LA_SER_ORIG);
 	      if (name == NULL)
 		{
 		  /* Do not try anything further.  */
diff --git a/elf/dl-object.c b/elf/dl-object.c
index 4dff99ed11..225e2ccf8a 100644
--- a/elf/dl-object.c
+++ b/elf/dl-object.c
@@ -81,7 +81,7 @@ _dl_new_object (char *realname, const char *libname, int type,
   struct link_map *new;
   struct libname_list *newname;
 #ifdef SHARED
-  size_t audit_space = naudit * sizeof (new->l_audit[0]);
+  size_t audit_space = naudit * sizeof (struct auditstate);
 #else
 # define audit_space 0
 #endif
@@ -134,10 +134,8 @@ _dl_new_object (char *realname, const char *libname, int type,
 
 #ifdef SHARED
   for (unsigned int cnt = 0; cnt < naudit; ++cnt)
-    {
-      new->l_audit[cnt].cookie = (uintptr_t) new;
-      /* new->l_audit[cnt].bindflags = 0; */
-    }
+    /* No need to initialize bindflags due to calloc.  */
+    link_map_audit_state (new, cnt)->cookie = (uintptr_t) new;
 #endif
 
   /* new->l_global = 0;	We use calloc therefore not necessary.  */
diff --git a/elf/dl-open.c b/elf/dl-open.c
index a9fd4cbced..8d699d3ff8 100644
--- a/elf/dl-open.c
+++ b/elf/dl-open.c
@@ -278,7 +278,10 @@ dl_open_worker (void *a)
 	  for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
 	    {
 	      if (afct->activity != NULL)
-		afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT);
+		{
+		  struct auditstate *state = link_map_audit_state (head, cnt);
+		  afct->activity (&state->cookie, LA_ACT_CONSISTENT);
+		}
 
 	      afct = afct->next;
 	    }
diff --git a/elf/dl-runtime.c b/elf/dl-runtime.c
index 342b794f54..8457862ba7 100644
--- a/elf/dl-runtime.c
+++ b/elf/dl-runtime.c
@@ -325,15 +325,18 @@ _dl_profile_fixup (
 		{
 		  /* XXX Check whether both DSOs must request action or
 		     only one */
-		  if ((l->l_audit[cnt].bindflags & LA_FLG_BINDFROM) != 0
-		      && (result->l_audit[cnt].bindflags & LA_FLG_BINDTO) != 0)
+		  struct auditstate *l_state = link_map_audit_state (l, cnt);
+		  struct auditstate *result_state
+		    = link_map_audit_state (result, cnt);
+		  if ((l_state->bindflags & LA_FLG_BINDFROM) != 0
+		      && (result_state->bindflags & LA_FLG_BINDTO) != 0)
 		    {
 		      if (afct->symbind != NULL)
 			{
 			  uintptr_t new_value
 			    = afct->symbind (&sym, reloc_result->boundndx,
-					     &l->l_audit[cnt].cookie,
-					     &result->l_audit[cnt].cookie,
+					     &l_state->cookie,
+					     &result_state->cookie,
 					     &flags,
 					     strtab2 + defsym->st_name);
 			  if (new_value != (uintptr_t) sym.st_value)
@@ -421,10 +424,13 @@ _dl_profile_fixup (
 		  & (LA_SYMB_NOPLTENTER << (2 * (cnt + 1)))) == 0)
 	    {
 	      long int new_framesize = -1;
+	      struct auditstate *l_state = link_map_audit_state (l, cnt);
+	      struct auditstate *bound_state
+		= link_map_audit_state (reloc_result->bound, cnt);
 	      uintptr_t new_value
 		= afct->ARCH_LA_PLTENTER (&sym, reloc_result->boundndx,
-					  &l->l_audit[cnt].cookie,
-					  &reloc_result->bound->l_audit[cnt].cookie,
+					  &l_state->cookie,
+					  &bound_state->cookie,
 					  regs, &flags, symname,
 					  &new_framesize);
 	      if (new_value != (uintptr_t) sym.st_value)
@@ -504,9 +510,11 @@ _dl_call_pltexit (struct link_map *l, ElfW(Word) reloc_arg,
 	  && (reloc_result->enterexit
 	      & (LA_SYMB_NOPLTEXIT >> (2 * cnt))) == 0)
 	{
+	  struct auditstate *l_state = link_map_audit_state (l, cnt);
+	  struct auditstate *bound_state
+	    = link_map_audit_state (reloc_result->bound, cnt);
 	  afct->ARCH_LA_PLTEXIT (&sym, reloc_result->boundndx,
-				 &l->l_audit[cnt].cookie,
-				 &reloc_result->bound->l_audit[cnt].cookie,
+				 &l_state->cookie, &bound_state->cookie,
 				 inregs, outregs, symname);
 	}
 
diff --git a/elf/dl-sym.c b/elf/dl-sym.c
index 8209342b13..21e025bc42 100644
--- a/elf/dl-sym.c
+++ b/elf/dl-sym.c
@@ -198,17 +198,20 @@ RTLD_NEXT used in code not dynamically loaded"));
 
 	      for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
 		{
+		  struct auditstate *match_audit
+		    = link_map_audit_state (match, cnt);
+		  struct auditstate *result_audit
+		    = link_map_audit_state (result, cnt);
 		  if (afct->symbind != NULL
-		      && ((match->l_audit[cnt].bindflags & LA_FLG_BINDFROM)
-			  != 0
-			  || ((result->l_audit[cnt].bindflags & LA_FLG_BINDTO)
+		      && ((match_audit->bindflags & LA_FLG_BINDFROM) != 0
+			  || ((result_audit->bindflags & LA_FLG_BINDTO)
 			      != 0)))
 		    {
 		      unsigned int flags = altvalue | LA_SYMB_DLSYM;
 		      uintptr_t new_value
 			= afct->symbind (&sym, ndx,
-					 &match->l_audit[cnt].cookie,
-					 &result->l_audit[cnt].cookie,
+					 &match_audit->cookie,
+					 &result_audit->cookie,
 					 &flags, strtab + ref->st_name);
 		      if (new_value != (uintptr_t) sym.st_value)
 			{
diff --git a/elf/rtld.c b/elf/rtld.c
index d54a7965b4..e22c7560c9 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -1025,9 +1025,9 @@ ERROR: audit interface '%s' requires version %d (maximum supported version %d);
   else
     *last_audit = (*last_audit)->next = &newp->ifaces;
 
-  /* The dynamic linker link map is statically allocated, initialize
-     the data now.  */
-  GL (dl_rtld_map).l_audit[GLRO (dl_naudit)].cookie
+  /* The dynamic linker link map is statically allocated, so the
+     cookie in _dl_new_object has not happened.  */
+  link_map_audit_state (&GL (dl_rtld_map), GLRO (dl_naudit))->cookie
     = (intptr_t) &GL (dl_rtld_map);
 
   ++GLRO(dl_naudit);
@@ -1046,9 +1046,9 @@ notify_audit_modules_of_loaded_object (struct link_map *map)
     {
       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;
+	  struct auditstate *state = link_map_audit_state (map, cnt);
+	  state->bindflags = afct->objopen (map, LM_ID_BASE, &state->cookie);
+	  map->l_audit_any_plt |= state->bindflags != 0;
 	}
 
       afct = afct->next;
@@ -1662,7 +1662,8 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]);
       for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
 	{
 	  if (afct->activity != NULL)
-	    afct->activity (&main_map->l_audit[cnt].cookie, LA_ACT_ADD);
+	    afct->activity (&link_map_audit_state (main_map, cnt)->cookie,
+			    LA_ACT_ADD);
 
 	  afct = afct->next;
 	}
@@ -2333,7 +2334,8 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]);
 	  for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
 	    {
 	      if (afct->activity != NULL)
-		afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT);
+		afct->activity (&link_map_audit_state (head, cnt)->cookie,
+				LA_ACT_CONSISTENT);
 
 	      afct = afct->next;
 	    }
diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
index a6991f3ac7..923bd4cf36 100644
--- a/sysdeps/generic/ldsodefs.h
+++ b/sysdeps/generic/ldsodefs.h
@@ -1174,7 +1174,13 @@ rtld_active (void)
      initialized and active ld.so copy.  */
   return GLRO(dl_init_all_dirs) != NULL;
 }
-#endif
+
+static inline struct auditstate *
+link_map_audit_state (struct link_map *l, size_t index)
+{
+  return &l->l_audit[index];
+}
+#endif /* SHARED */
 
 __END_DECLS