commit cda4f265c65fb6c4ce38ca1cf0a7e527c5e77cd5

Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>

Date:   Tue Jul 20 15:58:35 2021 -0300

    elf: Add _dl_audit_symbind_alt and _dl_audit_symbind

    It consolidates the code required to call la_symbind{32,64} audit

    callback.

    Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu.

    Reviewed-by: Florian Weimer <fweimer@redhat.com>

diff --git a/elf/Versions b/elf/Versions

index be88c48e6d45a937..c5d4342cf1f5124c 100644

--- a/elf/Versions

+++ b/elf/Versions

@@ -59,6 +59,7 @@ ld {

     _dl_argv; _dl_find_dso_for_object; _dl_get_tls_static_info;

     _dl_deallocate_tls; _dl_make_stack_executable;

     _dl_rtld_di_serinfo; _dl_starting_up; _dl_fatal_printf;

+    _dl_audit_symbind_alt;

     _rtld_global; _rtld_global_ro;

     # Only here for gdb while a better method is developed.

diff --git a/elf/dl-audit.c b/elf/dl-audit.c

index cb1c3de93cba447b..a21530f30bc5524b 100644

--- a/elf/dl-audit.c

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

@@ -16,6 +16,7 @@

    License along with the GNU C Library; if not, see

    <https://www.gnu.org/licenses/>.  */

+#include <assert.h>

 #include <ldsodefs.h>

 void

@@ -106,3 +107,124 @@ _dl_audit_objclose (struct link_map *l)

       afct = afct->next;

     }

 }

+

+void

+_dl_audit_symbind_alt (struct link_map *l, const ElfW(Sym) *ref, void **value,

+		       lookup_t result)

+{

+  if ((l->l_audit_any_plt | result->l_audit_any_plt) == 0)

+    return;

+

+  const char *strtab = (const char *) D_PTR (result, l_info[DT_STRTAB]);

+  /* Compute index of the symbol entry in the symbol table of the DSO with

+     the definition.  */

+  unsigned int ndx = (ref - (ElfW(Sym) *) D_PTR (result, l_info[DT_SYMTAB]));

+

+  unsigned int altvalue = 0;

+  /* Synthesize a symbol record where the st_value field is the result.  */

+  ElfW(Sym) sym = *ref;

+  sym.st_value = (ElfW(Addr)) *value;

+

+  struct audit_ifaces *afct = GLRO(dl_audit);

+  for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)

+    {

+      struct auditstate *match_audit = link_map_audit_state (l, cnt);

+      struct auditstate *result_audit = link_map_audit_state (result, cnt);

+      if (afct->symbind != NULL

+	  && ((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_audit->cookie,

+					       &result_audit->cookie,

+					       &flags, strtab + ref->st_name);

+	  if (new_value != (uintptr_t) sym.st_value)

+	    {

+	      altvalue = LA_SYMB_ALTVALUE;

+	      sym.st_value = new_value;

+	    }

+

+	  afct = afct->next;

+	}

+

+      *value = (void *) sym.st_value;

+    }

+}

+rtld_hidden_def (_dl_audit_symbind_alt)

+

+void

+_dl_audit_symbind (struct link_map *l, struct reloc_result *reloc_result,

+		   const ElfW(Sym) *defsym, DL_FIXUP_VALUE_TYPE *value,

+		   lookup_t result)

+{

+  reloc_result->bound = result;

+  /* Compute index of the symbol entry in the symbol table of the DSO with the

+     definition.  */

+  reloc_result->boundndx = (defsym - (ElfW(Sym) *) D_PTR (result,

+							  l_info[DT_SYMTAB]));

+

+  if ((l->l_audit_any_plt | result->l_audit_any_plt) == 0)

+    {

+      /* Set all bits since this symbol binding is not interesting.  */

+      reloc_result->enterexit = (1u << DL_NNS) - 1;

+      return;

+    }

+

+  /* Synthesize a symbol record where the st_value field is the result.  */

+  ElfW(Sym) sym = *defsym;

+  sym.st_value = DL_FIXUP_VALUE_ADDR (*value);

+

+  /* Keep track whether there is any interest in tracing the call in the lower

+     two bits.  */

+  assert (DL_NNS * 2 <= sizeof (reloc_result->flags) * 8);

+  assert ((LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT) == 3);

+  reloc_result->enterexit = LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT;

+

+  const char *strtab2 = (const void *) D_PTR (result, l_info[DT_STRTAB]);

+

+  unsigned int flags = 0;

+  struct audit_ifaces *afct = GLRO(dl_audit);

+  for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)

+    {

+      /* XXX Check whether both DSOs must request action or only one */

+      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_state->cookie,

+						   &result_state->cookie,

+						   &flags,

+						   strtab2 + defsym->st_name);

+	      if (new_value != (uintptr_t) sym.st_value)

+		{

+		  flags |= LA_SYMB_ALTVALUE;

+		  sym.st_value = new_value;

+		}

+	    }

+

+	  /* Remember the results for every audit library and store a summary

+	     in the first two bits.  */

+	  reloc_result->enterexit &= flags & (LA_SYMB_NOPLTENTER

+					      | LA_SYMB_NOPLTEXIT);

+	  reloc_result->enterexit |= ((flags & (LA_SYMB_NOPLTENTER

+						| LA_SYMB_NOPLTEXIT))

+				      << ((cnt + 1) * 2));

+	}

+      else

+	/* If the bind flags say this auditor is not interested, set the bits

+	   manually.  */

+	reloc_result->enterexit |= ((LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT)

+				    << ((cnt + 1) * 2));

+      afct = afct->next;

+    }

+

+  reloc_result->flags = flags;

+  *value = DL_FIXUP_ADDR_VALUE (sym.st_value);

+}

diff --git a/elf/dl-runtime.c b/elf/dl-runtime.c

index 4ccd7c30678fafad..d4840a7c17441126 100644

--- a/elf/dl-runtime.c

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

@@ -296,84 +296,7 @@ _dl_profile_fixup (

 	 auditing libraries the possibility to change the value and

 	 tell us whether further auditing is wanted.  */

       if (defsym != NULL && GLRO(dl_naudit) > 0)

-	{

-	  reloc_result->bound = result;

-	  /* Compute index of the symbol entry in the symbol table of

-	     the DSO with the definition.  */

-	  reloc_result->boundndx = (defsym

-				    - (ElfW(Sym) *) D_PTR (result,

-							   l_info[DT_SYMTAB]));

-

-	  /* Determine whether any of the two participating DSOs is

-	     interested in auditing.  */

-	  if ((l->l_audit_any_plt | result->l_audit_any_plt) != 0)

-	    {

-	      unsigned int flags = 0;

-	      struct audit_ifaces *afct = GLRO(dl_audit);

-	      /* Synthesize a symbol record where the st_value field is

-		 the result.  */

-	      ElfW(Sym) sym = *defsym;

-	      sym.st_value = DL_FIXUP_VALUE_ADDR (value);

-

-	      /* Keep track whether there is any interest in tracing

-		 the call in the lower two bits.  */

-	      assert (DL_NNS * 2 <= sizeof (reloc_result->flags) * 8);

-	      assert ((LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT) == 3);

-	      reloc_result->enterexit = LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT;

-

-	      const char *strtab2 = (const void *) D_PTR (result,

-							  l_info[DT_STRTAB]);

-

-	      for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)

-		{

-		  /* XXX Check whether both DSOs must request action or

-		     only one */

-		  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_state->cookie,

-					     &result_state->cookie,

-					     &flags,

-					     strtab2 + defsym->st_name);

-			  if (new_value != (uintptr_t) sym.st_value)

-			    {

-			      flags |= LA_SYMB_ALTVALUE;

-			      sym.st_value = new_value;

-			    }

-			}

-

-		      /* Remember the results for every audit library and

-			 store a summary in the first two bits.  */

-		      reloc_result->enterexit

-			&= flags & (LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT);

-		      reloc_result->enterexit

-			|= ((flags & (LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT))

-			    << ((cnt + 1) * 2));

-		    }

-		  else

-		    /* If the bind flags say this auditor is not interested,

-		       set the bits manually.  */

-		    reloc_result->enterexit

-		      |= ((LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT)

-			  << ((cnt + 1) * 2));

-

-		  afct = afct->next;

-		}

-

-	      reloc_result->flags = flags;

-	      value = DL_FIXUP_ADDR_VALUE (sym.st_value);

-	    }

-	  else

-	    /* Set all bits since this symbol binding is not interesting.  */

-	    reloc_result->enterexit = (1u << DL_NNS) - 1;

-	}

+	_dl_audit_symbind (l, reloc_result, defsym, &value, result);

 #endif

       /* Store the result for later runs.  */

diff --git a/elf/dl-sym-post.h b/elf/dl-sym-post.h

index 4c4f574633497789..f33934c92047f293 100644

--- a/elf/dl-sym-post.h

+++ b/elf/dl-sym-post.h

@@ -52,54 +52,9 @@ _dl_sym_post (lookup_t result, const ElfW(Sym) *ref, void *value,

      tell us whether further auditing is wanted.  */

   if (__glibc_unlikely (GLRO(dl_naudit) > 0))

     {

-      const char *strtab = (const char *) D_PTR (result,

-                                                 l_info[DT_STRTAB]);

-      /* Compute index of the symbol entry in the symbol table of

-         the DSO with the definition.  */

-      unsigned int ndx = (ref - (ElfW(Sym) *) D_PTR (result,

-                                                     l_info[DT_SYMTAB]));

-

       if (match == NULL)

         match = _dl_sym_find_caller_link_map (caller);

-

-      if ((match->l_audit_any_plt | result->l_audit_any_plt) != 0)

-        {

-          unsigned int altvalue = 0;

-          struct audit_ifaces *afct = GLRO(dl_audit);

-          /* Synthesize a symbol record where the st_value field is

-             the result.  */

-          ElfW(Sym) sym = *ref;

-          sym.st_value = (ElfW(Addr)) value;

-

-          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_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_audit->cookie,

-                                     &result_audit->cookie,

-                                     &flags, strtab + ref->st_name);

-                  if (new_value != (uintptr_t) sym.st_value)

-                    {

-                      altvalue = LA_SYMB_ALTVALUE;

-                      sym.st_value = new_value;

-                    }

-                }

-

-              afct = afct->next;

-            }

-

-          value = (void *) sym.st_value;

-        }

+      _dl_audit_symbind_alt (match, ref, &value, result);

     }

 #endif

   return value;

diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h

index 3db25c5be1acf871..fa55c3bde10de52e 100644

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

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

@@ -1294,6 +1294,16 @@ void _dl_audit_objopen (struct link_map *l, Lmid_t nsid)

 /* Call the la_objclose from the audit modules for the link_map L.  */

 void _dl_audit_objclose (struct link_map *l)

   attribute_hidden;

+

+/* Call the la_symbind{32,64} from the audit modules for the link_map L.  */

+void _dl_audit_symbind (struct link_map *l, struct reloc_result *reloc_result,

+			const ElfW(Sym) *defsym, DL_FIXUP_VALUE_TYPE *value,

+			lookup_t result)

+  attribute_hidden;

+/* Same as _dl_audit_symbind, but also sets LA_SYMB_DLSYM flag.  */

+void _dl_audit_symbind_alt (struct link_map *l, const ElfW(Sym) *ref,

+			    void **value, lookup_t result);

+rtld_hidden_proto (_dl_audit_symbind_alt)

 #endif /* SHARED */

 __END_DECLS