commit eff687e8462b0eaf65992a6031b54a4b1cd16796

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

Date:   Thu Jul 22 17:45:33 2021 -0300

    elf: Add _dl_audit_pltenter

    It consolidates the code required to call la_pltenter 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/dl-audit.c b/elf/dl-audit.c

index 0b6fac8e48877c93..15250c67e8ac1658 100644

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

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

@@ -17,7 +17,9 @@

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

 #include <assert.h>

+#include <link.h>

 #include <ldsodefs.h>

+#include <dl-machine.h>

 void

 _dl_audit_activity_map (struct link_map *l, int action)

@@ -243,3 +245,78 @@ _dl_audit_symbind (struct link_map *l, struct reloc_result *reloc_result,

   reloc_result->flags = flags;

   *value = DL_FIXUP_ADDR_VALUE (sym.st_value);

 }

+

+void

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

+		    DL_FIXUP_VALUE_TYPE *value, void *regs, long int *framesize)

+{

+  /* Don't do anything if no auditor wants to intercept this call.  */

+  if (GLRO(dl_naudit) == 0

+      || (reloc_result->enterexit & LA_SYMB_NOPLTENTER))

+    return;

+

+  /* Sanity check:  DL_FIXUP_VALUE_CODE_ADDR (value) should have been

+     initialized earlier in this function or in another thread.  */

+  assert (DL_FIXUP_VALUE_CODE_ADDR (*value) != 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 flags = 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)

+	{

+	  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_state->cookie, &bound_state->cookie,

+				      regs, &flags, symname, &new_framesize);

+	  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))

+				      << (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);

+}

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

index d4840a7c17441126..b46f7d7376e65361 100644

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

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

@@ -319,78 +319,7 @@ _dl_profile_fixup (

 #ifdef SHARED

   /* Auditing checkpoint: report the PLT entering and allow the

      auditors to change the value.  */

-  if (GLRO(dl_naudit) > 0

-      /* Don't do anything if no auditor wants to intercept this call.  */

-      && (reloc_result->enterexit & LA_SYMB_NOPLTENTER) == 0)

-    {

-      /* Sanity check:  DL_FIXUP_VALUE_CODE_ADDR (value) should have been

-	 initialized earlier in this function or in another thread.  */

-      assert (DL_FIXUP_VALUE_CODE_ADDR (value) != 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 flags = 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)

-	    {

-	      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_state->cookie,

-					  &bound_state->cookie,

-					  regs, &flags, symname,

-					  &new_framesize);

-	      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))

-		    << (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);

-    }

+  _dl_audit_pltenter (l, reloc_result, &value, regs, &framesize);

 #endif

   /* Store the frame size information.  */

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

index 03676b474c3d37a3..47a9dee5b1c0ca63 100644

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

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

@@ -1307,6 +1307,10 @@ void _dl_audit_symbind (struct link_map *l, struct reloc_result *reloc_result,

 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)

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

+			 DL_FIXUP_VALUE_TYPE *value, void *regs,

+			 long int *framesize)

+  attribute_hidden;

 #endif /* SHARED */

 __END_DECLS