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 775aab62af500f6c40c9feb559d082242d9aa8c9..25e91339b5107fc680b559353b472087177efed8 100644 (file)
--- a/elf/Versions
+++ b/elf/Versions
@@ -55,6 +55,7 @@ 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 cb1c3de93cba447b2b3948494dca66b882f7d743..a21530f30bc5524be0c19ebbec21ff46b0eeddc6 100644 (file)
--- 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 61c260ddb81b586c6d52c396ab9496b451301ba0..c4413c9165cec8cb4e4dd49a14609e1d3ce2c667 100644 (file)
--- a/elf/dl-runtime.c
+++ b/elf/dl-runtime.c
@@ -297,84 +297,7 @@ _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 d68c2d2b1cd43c9b3124999cc0aa9e4d05b342ba..a11095d3e8c3c93723ec2495490931381ce03477 100644 (file)
--- 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 2c9c615928ff52f0fadbfad3b46867c351dfb71a..eff1c1fa461f5fa5cd8c61bac5490d80c370ad40 100644 (file)
--- a/sysdeps/generic/ldsodefs.h
+++ b/sysdeps/generic/ldsodefs.h
@@ -1421,6 +1421,16 @@ 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 */
 
 #if PTHREAD_IN_LIBC && defined SHARED