commit e1d559f337de2c8ab68a6749dfe873477c883807

Author: Florian Weimer <fweimer@redhat.com>

Date:   Sat Nov 2 20:04:02 2019 +0100

    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

diff --git a/csu/libc-start.c b/csu/libc-start.c

index 494132368f8fe486..dfbf195328239a17 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 a9ecdff62dba88fb..1ece0ae1dd062d1e 100644

--- a/elf/dl-close.c

+++ b/elf/dl-close.c

@@ -305,8 +305,12 @@ _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;

 		}

@@ -481,7 +485,10 @@ _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;

 	    }

@@ -781,7 +788,10 @@ _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 3cfc262400da4db9..915ceb104e1c81d6 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 b190b28e32e47391..8f8869ff524ab9f2 100644

--- a/elf/dl-load.c

+++ b/elf/dl-load.c

@@ -979,7 +979,8 @@ _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;

 		}

@@ -1418,10 +1419,9 @@ 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;

@@ -1527,8 +1527,8 @@ 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;

@@ -1998,8 +1998,8 @@ _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 f6544a8fec45bdce..05a7750c65305771 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 46a4c1e5a3f8d2dd..7113c4a04f0fddbc 100644

--- a/elf/dl-open.c

+++ b/elf/dl-open.c

@@ -589,7 +589,10 @@ 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 3d2f4a7a76e616e3..72b03e000dcf190e 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 189628adc05aedf1..286cf7e27fd59f20 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 f557f39a70669c09..18335bc666f2b89d 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;

@@ -1660,7 +1660,8 @@ 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;

 	}

@@ -2331,7 +2332,8 @@ 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 3bdbdd6e67dacc85..a8fb0d211426e4b1 100644

--- a/sysdeps/generic/ldsodefs.h

+++ b/sysdeps/generic/ldsodefs.h

@@ -1197,7 +1197,13 @@ 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