i386-tdep: Verify architecture before proceeding with `set/show mpx'

Make sure the architecture is `bfd_arch_i386' before handling the `set
mpx' and `show mpx' commands, avoiding the issue with `i386_mpx_enabled'
interpreting `gdbarch->tdep' according to the `struct gdbarch_tdep'
definition in i386-tdep.h while indeed in a multi-target configuration
it may have a different layout and cause GDB to crash or at least
misbehave.

	gdb/
	* i386-tdep.c (i386_mpx_info_bounds): Make sure the architecture
	is `bfd_arch_i386' before proceeding.
	(i386_mpx_set_bounds): Likewise.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 6bc9805..4b642b8 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,11 @@
 2016-10-18  Maciej W. Rozycki  <macro@imgtec.com>
 
+       * i386-tdep.c (i386_mpx_info_bounds): Make sure the architecture
+       is `bfd_arch_i386' before proceeding.
+       (i386_mpx_set_bounds): Likewise.
+
+2016-10-18  Maciej W. Rozycki  <macro@imgtec.com>
+
        * tilegx-tdep.c (tilegx_analyze_prologue): Use the `long long'
        type for `operands'.
 

diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index ccdfec0..da8ff8e 100644 (file)
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -8857,7 +8857,8 @@ i386_mpx_info_bounds (char *args, int from_tty)
   struct gdbarch *gdbarch = get_current_arch ();
   struct type *data_ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
 
-  if (!i386_mpx_enabled ())
+  if (gdbarch_bfd_arch_info (gdbarch)->arch != bfd_arch_i386
+      || !i386_mpx_enabled ())
     {
       printf_unfiltered (_("Intel Memory Protection Extensions not "
                           "supported on this target.\n"));
@@ -8900,7 +8901,8 @@ i386_mpx_set_bounds (char *args, int from_tty)
   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
   struct type *data_ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
 
-  if (!i386_mpx_enabled ())
+  if (gdbarch_bfd_arch_info (gdbarch)->arch != bfd_arch_i386
+      || !i386_mpx_enabled ())
     error (_("Intel Memory Protection Extensions not supported\
  on this target."));