Description: when AT_RANDOM is not available, attempt to build randomization
 of stack guard value from the ASLR of stack and heap locations, and finally
 the hp_timing_t value.  Upstream glibc does not want this patch, as they
 feel AT_RANDOM is sufficient.
Author: Jakub Jelinek
Origin: http://cvs.fedora.redhat.com/viewvc/devel/glibc/
Forwarded: not-needed

---
 elf/tst-stackguard1.c               |    8 ++++++--
 nptl/tst-stackguard1.c              |    8 ++++++--
 sysdeps/unix/sysv/linux/dl-osinfo.h |   29 +++++++++++++++++++++++++++++
 3 files changed, 41 insertions(+), 4 deletions(-)

--- a/sysdeps/unix/sysv/linux/dl-osinfo.h
+++ b/sysdeps/unix/sysv/linux/dl-osinfo.h
@@ -17,10 +17,13 @@
    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307 USA.  */
 
+#include <errno.h>
 #include <kernel-features.h>
 #include <dl-sysdep.h>
 #include <fcntl.h>
 #include <stdint.h>
+#include <hp-timing.h>
+#include <endian.h>
 
 #ifndef MIN
 # define MIN(a,b) (((a)<(b))?(a):(b))
@@ -80,6 +83,32 @@
       unsigned char *p = (unsigned char *) &ret;
       p[sizeof (ret) - 1] = 255;
       p[sizeof (ret) - 2] = '\n';
+#ifdef HP_TIMING_NOW
+      hp_timing_t hpt;
+      HP_TIMING_NOW (hpt);
+      hpt = (hpt & 0xffff) << 8;
+      ret ^= hpt;
+#endif
+      uintptr_t stk;
+      /* Avoid GCC being too smart.  */
+      asm ("" : "=r" (stk) : "r" (p));
+      stk &= 0x7ffff0;
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+      stk <<= (__WORDSIZE - 23);
+#elif __WORDSIZE == 64
+      stk <<= 31;
+#endif
+      ret ^= stk;
+      /* Avoid GCC being too smart.  */
+      p = (unsigned char *) &errno;
+      asm ("" : "=r" (stk) : "r" (p));
+      stk &= 0x7fff00;
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+      stk <<= (__WORDSIZE - 29);
+#else
+      stk >>= 8;
+#endif
+      ret ^= stk;
     }
   else
 #endif
Index: b/elf/tst-stackguard1.c
===================================================================
--- a/elf/tst-stackguard1.c
+++ b/elf/tst-stackguard1.c
@@ -160,17 +160,21 @@
      the 16 runs, something is very wrong.  */
   int ndifferences = 0;
   int ndefaults = 0;
+  int npartlyrandomized = 0;
   for (i = 0; i < N; ++i) 
     {
       if (child_stack_chk_guards[i] != child_stack_chk_guards[i+1])
 	ndifferences++;
       else if (child_stack_chk_guards[i] == default_guard)
 	ndefaults++;
+      else if (*(char *) &child_stack_chk_guards[i] == 0)
+	npartlyrandomized++;
     }
 
-  printf ("differences %d defaults %d\n", ndifferences, ndefaults);
+  printf ("differences %d defaults %d partly randomized %d\n",
+	  ndifferences, ndefaults, npartlyrandomized);
 
-  if (ndifferences < N / 2 && ndefaults < N / 2)
+  if ((ndifferences + ndefaults + npartlyrandomized) < 3 * N / 4)
     {
       puts ("stack guard canaries are not randomized enough");
       puts ("nor equal to the default canary value");
Index: b/nptl/tst-stackguard1.c
===================================================================
--- a/nptl/tst-stackguard1.c
+++ b/nptl/tst-stackguard1.c
@@ -190,17 +190,21 @@
      the 16 runs, something is very wrong.  */
   int ndifferences = 0;
   int ndefaults = 0;
+  int npartlyrandomized = 0;
   for (i = 0; i < N; ++i) 
     {
       if (child_stack_chk_guards[i] != child_stack_chk_guards[i+1])
 	ndifferences++;
       else if (child_stack_chk_guards[i] == default_guard)
 	ndefaults++;
+      else if (*(char *) &child_stack_chk_guards[i] == 0)
+	npartlyrandomized++;
     }
 
-  printf ("differences %d defaults %d\n", ndifferences, ndefaults);
+  printf ("differences %d defaults %d partly randomized %d\n",
+	  ndifferences, ndefaults, npartlyrandomized);
 
-  if (ndifferences < N / 2 && ndefaults < N / 2)
+  if ((ndifferences + ndefaults + npartlyrandomized) < 3 * N / 4)
     {
       puts ("stack guard canaries are not randomized enough");
       puts ("nor equal to the default canary value");