Certain kernels on s390 provide extra read permissions on executable

segments. See discussion here: https://bugs.kde.org/show_bug.cgi?id=345824#c4
Making sure that rx and x compare equal.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15075 a5019735-40e9-0310-863c-91ae7b9d1cf9

Author: florian

coregrind/m_aspacemgr/aspacemgr-linux.c

@@ -770,7 +770,7 @@ static void sync_check_mapping_callback ( Addr addr, SizeT len, UInt prot,
                                           const HChar* filename )
 {
    Int  iLo, iHi, i;
-   Bool sloppyXcheck;
+   Bool sloppyXcheck, sloppyRcheck;
 
    /* If a problem has already been detected, don't continue comparing
       segments, so as to avoid flooding the output with error
@@ -814,6 +814,14 @@ static void sync_check_mapping_callback ( Addr addr, SizeT len, UInt prot,
    sloppyXcheck = False;
 #  endif
 
+   /* Some kernels on s390 provide 'r' permission even when it was not
+      explicitly requested. It seems that 'x' permission implies 'r'. */
+#  if defined(VGA_s390x)
+   sloppyRcheck = True;
+#  else
+   sloppyRcheck = False;
+#  endif
+
    /* NSegments iLo .. iHi inclusive should agree with the presented
       data. */
    for (i = iLo; i <= iHi; i++) {
@@ -868,6 +876,11 @@ static void sync_check_mapping_callback ( Addr addr, SizeT len, UInt prot,
          seg_prot |= VKI_PROT_EXEC;
       }
 
+      if (sloppyRcheck && (prot & (VKI_PROT_EXEC | VKI_PROT_READ)) ==
+          (VKI_PROT_EXEC | VKI_PROT_READ)) {
+         seg_prot |= VKI_PROT_READ;
+      }
+
       same = same
              && seg_prot == prot
              && (cmp_devino