[patch] binutils-2.23-gold-pt-pax-flags.patch

binutils-2.23-gold-pt-pax-flags.patch (text/plain), 6.56 KB, created by iGentoo on 2012-10-24 06:29:17 UTC

 elfcpp/elfcpp.h | 17 ++++++++++++++++-
 gold/layout.cc  | 18 ++++++++++++++++--
 gold/options.cc |  8 ++++++++
 gold/options.h  | 31 +++++++++++++++++++++++++++++++
 gold/script.cc  |  1 +
 5 files changed, 72 insertions(+), 3 deletions(-)

diff --git a/elfcpp/elfcpp.h b/elfcpp/elfcpp.h
index e4f9f1f..29b71a8 100644
--- a/elfcpp/elfcpp.h
+++ b/elfcpp/elfcpp.h
@@ -479,6 +479,8 @@ enum PT
   PT_GNU_STACK = 0x6474e551,
   // Read only after relocation.
   PT_GNU_RELRO = 0x6474e552,
+  // PaX flags
+  PT_PAX_FLAGS = 0x65041580,
   // Platform architecture compatibility information
   PT_ARM_ARCHEXT = 0x70000000,
   // Exception unwind tables
@@ -499,7 +501,20 @@ enum PF
   PF_W = 0x2,
   PF_R = 0x4,
   PF_MASKOS = 0x0ff00000,
-  PF_MASKPROC = 0xf0000000
+  PF_MASKPROC = 0xf0000000,
+  /* Flags to control PaX behavior. */
+  PF_PAGEEXEC   = (1 << 4),	/* Enable  PAGEEXEC */
+  PF_NOPAGEEXEC = (1 << 5),	/* Disable PAGEEXEC */
+  PF_SEGMEXEC   = (1 << 6),	/* Enable  SEGMEXEC */
+  PF_NOSEGMEXEC = (1 << 7),	/* Disable SEGMEXEC */
+  PF_MPROTECT   = (1 << 8),	/* Enable  MPROTECT */
+  PF_NOMPROTECT = (1 << 9),	/* Disable MPROTECT */
+  PF_RANDEXEC   = (1 << 10),	/* Enable  RANDEXEC */
+  PF_NORANDEXEC = (1 << 11),	/* Disable RANDEXEC */
+  PF_EMUTRAMP   = (1 << 12),	/* Enable  EMUTRAMP */
+  PF_NOEMUTRAMP = (1 << 13),	/* Disable EMUTRAMP */
+  PF_RANDMMAP   = (1 << 14),	/* Enable  RANDMMAP */
+  PF_NORANDMMAP = (1 << 15)	/* Disable RANDMMAP */
 };
 
 // Symbol binding from Sym st_info field.
diff --git a/gold/layout.cc b/gold/layout.cc
index ad667ab..b5f0b48 100644
--- a/gold/layout.cc
+++ b/gold/layout.cc
@@ -1878,7 +1878,7 @@ Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags,
   else
     {
       this->input_with_gnu_stack_note_ = true;
-      if ((gnu_stack_flags & elfcpp::SHF_EXECINSTR) != 0)
+      if ((gnu_stack_flags & elfcpp::SHF_EXECINSTR) != 0)
 	{
 	  this->input_requires_executable_stack_ = true;
 	  if (parameters->options().warn_execstack()
@@ -2731,7 +2731,7 @@ Layout::create_executable_stack_info()
     return;
   else
     {
-      if (this->input_requires_executable_stack_)
+      if (this->input_requires_executable_stack_)
 	is_stack_executable = true;
       else if (this->input_without_gnu_stack_note_)
 	is_stack_executable =
@@ -2757,6 +2757,20 @@ Layout::create_executable_stack_info()
       if (is_stack_executable)
 	flags |= elfcpp::PF_X;
       this->make_output_segment(elfcpp::PT_GNU_STACK, flags);
+
+      int pax_flags = elfcpp::PF_NORANDEXEC;
+      if (parameters->options().is_execheap_set()) {
+        if (parameters->options().is_heap_executable())
+          pax_flags |= elfcpp::PF_NOMPROTECT;
+        else
+          pax_flags |= elfcpp::PF_MPROTECT;
+      }
+
+      if (is_stack_executable)
+        pax_flags |= elfcpp::PF_EMUTRAMP;
+      else
+        pax_flags |= elfcpp::PF_NOEMUTRAMP;
+      this->make_output_segment(elfcpp::PT_PAX_FLAGS, pax_flags);
     }
 }
 
diff --git a/gold/options.cc b/gold/options.cc
index fe9a00e..6db9e5c 100644
--- a/gold/options.cc
+++ b/gold/options.cc
@@ -912,6 +912,7 @@ namespace gold
 General_options::General_options()
   : printed_version_(false),
     execstack_status_(EXECSTACK_FROM_INPUT),
+    execheap_status_(EXECHEAP_FROM_INPUT),
     icf_status_(ICF_NONE),
     static_(false),
     do_demangle_(false),
@@ -1051,6 +1052,13 @@ General_options::finalize()
   else if (this->noexecstack())
     this->set_execstack_status(EXECSTACK_NO);
 
+  // execheap_status_ is a three-state variable; update it based on
+  // -z [no]execheap.
+  if (this->execheap())
+    this->set_execheap_status(EXECHEAP_YES);
+  else if (this->noexecheap())
+    this->set_execheap_status(EXECHEAP_NO);
+
   // icf_status_ is a three-state variable; update it based on the
   // value of this->icf().
   if (strcmp(this->icf(), "none") == 0)
diff --git a/gold/options.h b/gold/options.h
index 50762a5..378ae6c 100644
--- a/gold/options.h
+++ b/gold/options.h
@@ -1190,6 +1190,8 @@ class General_options
               NULL);
   DEFINE_bool(execstack, options::DASH_Z, '\0', false,
               N_("Mark output as requiring executable stack"), NULL);
+  DEFINE_bool(execheap, options::DASH_Z, '\0', false,
+              N_("Mark output as requiring executable heap"), NULL);
   DEFINE_bool(initfirst, options::DASH_Z, '\0', false,
 	      N_("Mark DSO to be initialized first at runtime"),
 	      NULL);
@@ -1226,6 +1228,8 @@ class General_options
 	      NULL);
   DEFINE_bool(noexecstack, options::DASH_Z, '\0', false,
               N_("Mark output as not requiring executable stack"), NULL);
+  DEFINE_bool(noexecheap, options::DASH_Z, '\0', false,
+              N_("Mark output as not requiring executable heap"), NULL);
   DEFINE_bool(now, options::DASH_Z, '\0', false,
 	      N_("Mark object for immediate function binding"),
 	      NULL);
@@ -1327,6 +1331,16 @@ class General_options
   is_stack_executable() const
   { return this->execstack_status_ == EXECSTACK_YES; }
 
+  // These are the best way to get access to the execheap state,
+  // not execheap() and noexecheap() which are hard to use properly.
+  bool
+  is_execheap_set() const
+  { return this->execheap_status_ != EXECHEAP_FROM_INPUT; }
+
+  bool
+  is_heap_executable() const
+  { return this->execheap_status_ == EXECHEAP_YES; }
+
   bool
   icf_enabled() const
   { return this->icf_status_ != ICF_NONE; }
@@ -1451,6 +1465,17 @@ class General_options
     EXECSTACK_NO
   };
 
+  // Whether to mark the heap as executable.
+  enum Execheap
+  {
+    // Not set on command line.
+    EXECHEAP_FROM_INPUT,
+    // Mark the heap as executable (-z execheap).
+    EXECHEAP_YES,
+    // Mark the heap as not executable (-z noexecheap).
+    EXECHEAP_NO
+  };
+
   enum Icf_status
   {
     // Do not fold any functions (Default or --icf=none).
@@ -1470,6 +1495,10 @@ class General_options
   { this->execstack_status_ = value; }
 
   void
+  set_execheap_status(Execheap value)
+  { this->execheap_status_ = value; }
+
+  void
   set_do_demangle(bool value)
   { this->do_demangle_ = value; }
 
@@ -1498,6 +1527,8 @@ class General_options
   bool printed_version_;
   // Whether to mark the stack as executable.
   Execstack execstack_status_;
+  // Whether to mark the heap as executable.
+  Execheap execheap_status_;
   // Whether to do code folding.
   Icf_status icf_status_;
   // Whether to do a static link.
diff --git a/gold/script.cc b/gold/script.cc
index 6a10c40..f6b1ca1 100644
--- a/gold/script.cc
+++ b/gold/script.cc
@@ -3262,6 +3262,7 @@ static struct
   PHDR_TYPE(PT_TLS),
   PHDR_TYPE(PT_GNU_EH_FRAME),
   PHDR_TYPE(PT_GNU_STACK),
+  PHDR_TYPE(PT_PAX_FLAGS),
   PHDR_TYPE(PT_GNU_RELRO)
 };