2.5-18.1

1 files changed, 268 insertions, 52 deletions

diff --git a/elf/dl-runtime.c b/elf/dl-runtime.c
index a0aecda..ee2b8b5 100644
--- a/elf/dl-runtime.c
+++ b/elf/dl-runtime.c
@@ -1,5 +1,5 @@
 /* On-demand PLT fixup for shared objects.
-   Copyright (C) 1995-2002, 2003, 2004 Free Software Foundation, Inc.
+   Copyright (C) 1995-2006, 2007 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -22,8 +22,12 @@
 #include <alloca.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <sys/param.h>
 #include <ldsodefs.h>
+#include <sysdep-cancel.h>
 #include "dynamic-link.h"
+#include <tls.h>
+
 
 #if (!defined ELF_MACHINE_NO_RELA && !defined ELF_MACHINE_PLT_REL) \
     || ELF_MACHINE_NO_REL
@@ -51,15 +55,15 @@
    function.  */
 
 #ifndef ELF_MACHINE_NO_PLT
-static ElfW(Addr)
-__attribute ((used, noinline)) ARCH_FIXUP_ATTRIBUTE
-fixup (
+DL_FIXUP_VALUE_TYPE
+__attribute ((noinline)) ARCH_FIXUP_ATTRIBUTE
+_dl_fixup (
 # ifdef ELF_MACHINE_RUNTIME_FIXUP_ARGS
-        ELF_MACHINE_RUNTIME_FIXUP_ARGS,
+	   ELF_MACHINE_RUNTIME_FIXUP_ARGS,
 # endif
-	/* GKM FIXME: Fix trampoline to pass bounds so we can do
-	   without the `__unbounded' qualifier.  */
-       struct link_map *__unbounded l, ElfW(Word) reloc_offset)
+	   /* GKM FIXME: Fix trampoline to pass bounds so we can do
+	      without the `__unbounded' qualifier.  */
+	   struct link_map *__unbounded l, ElfW(Word) reloc_offset)
 {
   const ElfW(Sym) *const symtab
     = (const void *) D_PTR (l, l_info[DT_SYMTAB]);
@@ -70,7 +74,7 @@ fixup (
   const ElfW(Sym) *sym = &symtab[ELFW(R_SYM) (reloc->r_info)];
   void *const rel_addr = (void *)(l->l_addr + reloc->r_offset);
   lookup_t result;
-  ElfW(Addr) value;
+  DL_FIXUP_VALUE_TYPE value;
 
   /* Sanity check that we're really looking at a PLT relocation.  */
   assert (ELFW(R_TYPE)(reloc->r_info) == ELF_MACHINE_JMP_SLOT);
@@ -80,8 +84,6 @@ fixup (
   if (__builtin_expect (ELFW(ST_VISIBILITY) (sym->st_other), 0) == 0)
     {
       const struct r_found_version *version = NULL;
-      // XXX Why exactly do we have the differentiation of the flags here?
-      int flags = DL_LOOKUP_ADD_DEPENDENCY;
 
       if (l->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
 	{
@@ -91,27 +93,35 @@ fixup (
 	  version = &l->l_versions[ndx];
 	  if (version->hash == 0)
 	    version = NULL;
-	  else
-	    flags = 0;
 	}
 
-      result = _dl_lookup_symbol_x (strtab + sym->st_name, l, &sym,
-				    l->l_scope, version, ELF_RTYPE_CLASS_PLT,
-				    DL_LOOKUP_ADD_DEPENDENCY, NULL);
+      /* We need to keep the scope around so do some locking.  This is
+	 not necessary for objects which cannot be unloaded or when
+	 we are not using any threads (yet).  */
+      int flags = DL_LOOKUP_ADD_DEPENDENCY;
+      if (!RTLD_SINGLE_THREAD_P)
+	THREAD_GSCOPE_SET_FLAG ();
+
+      result = _dl_lookup_symbol_x (strtab + sym->st_name, l, &sym, l->l_scope,
+				    version, ELF_RTYPE_CLASS_PLT, flags, NULL);
+
+      /* We are done with the global scope.  */
+      if (!RTLD_SINGLE_THREAD_P)
+	THREAD_GSCOPE_RESET_FLAG ();
 
       /* Currently result contains the base load address (or link map)
 	 of the object that defines sym.  Now add in the symbol
 	 offset.  */
-      value = (sym ? LOOKUP_VALUE_ADDRESS (result) + sym->st_value : 0);
+      value = DL_FIXUP_MAKE_VALUE (result,
+				   sym ? (LOOKUP_VALUE_ADDRESS (result)
+					  + sym->st_value) : 0);
     }
   else
     {
       /* We already found the symbol.  The module (and therefore its load
 	 address) is also known.  */
-      value = l->l_addr + sym->st_value;
-#ifdef DL_LOOKUP_RETURNS_MAP
+      value = DL_FIXUP_MAKE_VALUE (l, l->l_addr + sym->st_value);
       result = l;
-#endif
     }
 
   /* And now perhaps the relocation addend.  */
@@ -127,45 +137,45 @@ fixup (
 
 #if !defined PROF && !defined ELF_MACHINE_NO_PLT && !__BOUNDED_POINTERS__
 
-static ElfW(Addr)
-__attribute ((used, noinline)) ARCH_FIXUP_ATTRIBUTE
-profile_fixup (
+DL_FIXUP_VALUE_TYPE
+__attribute ((noinline)) ARCH_FIXUP_ATTRIBUTE
+_dl_profile_fixup (
 #ifdef ELF_MACHINE_RUNTIME_FIXUP_ARGS
-       ELF_MACHINE_RUNTIME_FIXUP_ARGS,
+		   ELF_MACHINE_RUNTIME_FIXUP_ARGS,
 #endif
-       struct link_map *l, ElfW(Word) reloc_offset, ElfW(Addr) retaddr)
+		   struct link_map *l, ElfW(Word) reloc_offset,
+		   ElfW(Addr) retaddr, void *regs, long int *framesizep)
 {
   void (*mcount_fct) (ElfW(Addr), ElfW(Addr)) = INTUSE(_dl_mcount);
-  ElfW(Addr) *resultp;
-  lookup_t result;
-  ElfW(Addr) value;
 
   /* This is the address in the array where we store the result of previous
      relocations.  */
-  resultp = &l->l_reloc_result[reloc_offset / sizeof (PLTREL)];
+  struct reloc_result *reloc_result
+    = &l->l_reloc_result[reloc_offset / sizeof (PLTREL)];
+  DL_FIXUP_VALUE_TYPE *resultp = &reloc_result->addr;
 
-  value = *resultp;
-  if (value == 0)
+  DL_FIXUP_VALUE_TYPE value = *resultp;
+  if (DL_FIXUP_VALUE_CODE_ADDR (value) == 0)
     {
       /* This is the first time we have to relocate this object.  */
       const ElfW(Sym) *const symtab
 	= (const void *) D_PTR (l, l_info[DT_SYMTAB]);
-      const char *strtab = (const void *) D_PTR (l, l_info[DT_STRTAB]);
+      const char *strtab = (const char *) D_PTR (l, l_info[DT_STRTAB]);
 
       const PLTREL *const reloc
 	= (const void *) (D_PTR (l, l_info[DT_JMPREL]) + reloc_offset);
-      const ElfW(Sym) *sym = &symtab[ELFW(R_SYM) (reloc->r_info)];
+      const ElfW(Sym) *refsym = &symtab[ELFW(R_SYM) (reloc->r_info)];
+      const ElfW(Sym) *defsym = refsym;
+      lookup_t result;
 
       /* Sanity check that we're really looking at a PLT relocation.  */
       assert (ELFW(R_TYPE)(reloc->r_info) == ELF_MACHINE_JMP_SLOT);
 
       /* Look up the target symbol.  If the symbol is marked STV_PROTECTED
 	 don't look in the global scope.  */
-      if (__builtin_expect (ELFW(ST_VISIBILITY) (sym->st_other), 0) == 0)
+      if (__builtin_expect (ELFW(ST_VISIBILITY) (refsym->st_other), 0) == 0)
 	{
 	  const struct r_found_version *version = NULL;
-	  // XXX Why exactly do we have the differentiation of the flags here?
-	  int flags = DL_LOOKUP_ADD_DEPENDENCY;
 
 	  if (l->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
 	    {
@@ -175,38 +185,208 @@ profile_fixup (
 	      version = &l->l_versions[ndx];
 	      if (version->hash == 0)
 		version = NULL;
-	      else
-		flags = 0;
 	    }
 
-	  result = _dl_lookup_symbol_x (strtab + sym->st_name, l, &sym,
-					l->l_scope, version,
-					ELF_RTYPE_CLASS_PLT,
-					DL_LOOKUP_ADD_DEPENDENCY, NULL);
+	  /* We need to keep the scope around so do some locking.  This is
+	     not necessary for objects which cannot be unloaded or when
+	     we are not using any threads (yet).  */
+	  int flags = DL_LOOKUP_ADD_DEPENDENCY;
+	  if (!RTLD_SINGLE_THREAD_P)
+	    THREAD_GSCOPE_SET_FLAG ();
+
+	  result = _dl_lookup_symbol_x (strtab + refsym->st_name, l,
+					&defsym, l->l_scope, version,
+					ELF_RTYPE_CLASS_PLT, flags, NULL);
+
+	  /* We are done with the global scope.  */
+	  if (!RTLD_SINGLE_THREAD_P)
+	    THREAD_GSCOPE_RESET_FLAG ();
 
 	  /* Currently result contains the base load address (or link map)
 	     of the object that defines sym.  Now add in the symbol
 	     offset.  */
-	  value = (sym ? LOOKUP_VALUE_ADDRESS (result) + sym->st_value : 0);
+	  value = DL_FIXUP_MAKE_VALUE (result,
+				       defsym != NULL
+				       ? LOOKUP_VALUE_ADDRESS (result)
+					 + defsym->st_value : 0);
 	}
       else
 	{
 	  /* We already found the symbol.  The module (and therefore its load
 	     address) is also known.  */
-	  value = l->l_addr + sym->st_value;
-#ifdef DL_LOOKUP_RETURNS_MAP
+	  value = DL_FIXUP_MAKE_VALUE (l, l->l_addr + refsym->st_value);
 	  result = l;
-#endif
 	}
       /* And now perhaps the relocation addend.  */
       value = elf_machine_plt_value (l, reloc, value);
 
+#ifdef SHARED
+      /* Auditing checkpoint: we have a new binding.  Provide the
+	 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 altvalue = 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 */
+		  if ((l->l_audit[cnt].bindflags & LA_FLG_BINDFROM) != 0
+		      && (result->l_audit[cnt].bindflags & LA_FLG_BINDTO) != 0)
+		    {
+		      unsigned int flags = altvalue;
+		      if (afct->symbind != NULL)
+			{
+			  uintptr_t new_value
+			    = afct->symbind (&sym, reloc_result->boundndx,
+					     &l->l_audit[cnt].cookie,
+					     &result->l_audit[cnt].cookie,
+					     &flags,
+					     strtab2 + defsym->st_name);
+			  if (new_value != (uintptr_t) sym.st_value)
+			    {
+			      altvalue = 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 = altvalue;
+	      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;
+	}
+#endif
+
       /* Store the result for later runs.  */
       if (__builtin_expect (! GLRO(dl_bind_not), 1))
 	*resultp = value;
     }
 
-  (*mcount_fct) (retaddr, value);
+  /* By default we do not call the pltexit function.  */
+  long int framesize = -1;
+
+#ifdef SHARED
+  /* Auditing checkpoint: report the PLT entering and allow the
+     auditors to change the value.  */
+  if (DL_FIXUP_VALUE_CODE_ADDR (value) != 0 && GLRO(dl_naudit) > 0
+      /* Don't do anything if no auditor wants to intercept this call.  */
+      && (reloc_result->enterexit & LA_SYMB_NOPLTENTER) == 0)
+    {
+      ElfW(Sym) *defsym = ((ElfW(Sym) *) D_PTR (reloc_result->bound,
+						l_info[DT_SYMTAB])
+			   + reloc_result->boundndx);
+
+      /* Set up the sym parameter.  */
+      ElfW(Sym) sym = *defsym;
+      sym.st_value = DL_FIXUP_VALUE_ADDR (value);
+
+      /* Get the symbol name.  */
+      const char *strtab = (const void *) D_PTR (reloc_result->bound,
+						 l_info[DT_STRTAB]);
+      const char *symname = strtab + sym.st_name;
+
+      /* Keep track of overwritten addresses.  */
+      unsigned int altvalue = reloc_result->flags;
+
+      struct audit_ifaces *afct = GLRO(dl_audit);
+      for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
+	{
+ 	  if (afct->ARCH_LA_PLTENTER != NULL
+	      && (reloc_result->enterexit
+		  & (LA_SYMB_NOPLTENTER << (2 * (cnt + 1)))) == 0)
+	    {
+	      unsigned int flags = altvalue;
+	      long int new_framesize = -1;
+	      uintptr_t new_value
+		= afct->ARCH_LA_PLTENTER (&sym, reloc_result->boundndx,
+					  &l->l_audit[cnt].cookie,
+					  &reloc_result->bound->l_audit[cnt].cookie,
+					  regs, &flags, symname,
+					  &new_framesize);
+	      if (new_value != (uintptr_t) sym.st_value)
+		{
+		  altvalue = 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))
+		    << (2 * (cnt + 1)));
+
+	      if ((reloc_result->enterexit & (LA_SYMB_NOPLTEXIT
+					      << (2 * (cnt + 1))))
+		  == 0 && new_framesize != -1 && framesize != -2)
+		{
+		  /* If this is the first call providing information,
+		     use it.  */
+		  if (framesize == -1)
+		    framesize = new_framesize;
+		  /* If two pltenter calls provide conflicting information,
+		     use the larger value.  */
+		  else if (new_framesize != framesize)
+		    framesize = MAX (new_framesize, framesize);
+		}
+	    }
+
+	  afct = afct->next;
+	}
+
+      value = DL_FIXUP_ADDR_VALUE (sym.st_value);
+    }
+#endif
+
+  /* Store the frame size information.  */
+  *framesizep = framesize;
+
+  (*mcount_fct) (retaddr, DL_FIXUP_VALUE_CODE_ADDR (value));
 
   return value;
 }
@@ -214,9 +394,45 @@ profile_fixup (
 #endif /* PROF && ELF_MACHINE_NO_PLT */
 
 
-/* This macro is defined in dl-machine.h to define the entry point called
-   by the PLT.  The `fixup' function above does the real work, but a little
-   more twiddling is needed to get the stack right and jump to the address
-   finally resolved.  */
+#include <stdio.h>
+void
+ARCH_FIXUP_ATTRIBUTE
+_dl_call_pltexit (struct link_map *l, ElfW(Word) reloc_offset,
+		  const void *inregs, void *outregs)
+{
+#ifdef SHARED
+  /* This is the address in the array where we store the result of previous
+     relocations.  */
+  // XXX Maybe the bound information must be stored on the stack since
+  // XXX with bind_not a new value could have been stored in the meantime.
+  struct reloc_result *reloc_result
+    = &l->l_reloc_result[reloc_offset / sizeof (PLTREL)];
+  ElfW(Sym) *defsym = ((ElfW(Sym) *) D_PTR (reloc_result->bound,
+					    l_info[DT_SYMTAB])
+		       + reloc_result->boundndx);
+
+  /* Set up the sym parameter.  */
+  ElfW(Sym) sym = *defsym;
+
+  /* Get the symbol name.  */
+  const char *strtab = (const void *) D_PTR (reloc_result->bound,
+					     l_info[DT_STRTAB]);
+  const char *symname = strtab + sym.st_name;
+
+  struct audit_ifaces *afct = GLRO(dl_audit);
+  for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
+    {
+      if (afct->ARCH_LA_PLTEXIT != NULL
+	  && (reloc_result->enterexit
+	      & (LA_SYMB_NOPLTEXIT >> (2 * cnt))) == 0)
+	{
+	  afct->ARCH_LA_PLTEXIT (&sym, reloc_result->boundndx,
+				 &l->l_audit[cnt].cookie,
+				 &reloc_result->bound->l_audit[cnt].cookie,
+				 inregs, outregs, symname);
+	}
 
-ELF_MACHINE_RUNTIME_TRAMPOLINE
+      afct = afct->next;
+    }
+#endif
+}