gdb: xtensa: handle privileged registers

xtensa GDB may be used with both bare-metal and linux-based
applications. In case of bare-metal application gdbserver is able to
provide information about all CPU registers: both unprivileged and
privileged. In case of linux-based application only a small subset of
privileged state is available. Currently xtensa GDB only expects
unprivileged registers in 'g' packets and it fails to communicate with
server that sends both privileged and unprivileged registers.

Allow bare-metal xtensa GDB to deal with both privileged and
unprivileged registers by initializing tdep->num_regs with the total
number of target CPU registers. Keep linux-based xtensa GDB
functionality as is by copying tdep->num_nopriv_regs to tdep->num_regs.

gdb/
2018-05-09  Max Filippov  <jcmvbkbc@gmail.com>

	* xtensa-linux-tdep.c (xtensa-tdep.h): New include.
	(xtensa_linux_init_abi): Limit tdep->num_regs by
	tdep->num_nopriv_regs.
	* xtensa-tdep.c (xtensa_derive_tdep): Calculate
	tdep->num_nopriv_regs and only copy it to tdep->num_regs if it's
	not initialized.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index a1059aef8d777882eab47dc74decfad4f85486cd..728ed8ca414799644a39e6504792238907f41d5d 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,12 @@
+2018-05-09  Max Filippov  <jcmvbkbc@gmail.com>
+
+       * xtensa-linux-tdep.c (xtensa-tdep.h): New include.
+       (xtensa_linux_init_abi): Limit tdep->num_regs by
+       tdep->num_nopriv_regs.
+       * xtensa-tdep.c (xtensa_derive_tdep): Calculate
+       tdep->num_nopriv_regs and only copy it to tdep->num_regs if it's
+       not initialized.
+
 2018-05-08  Simon Marchi  <simon.marchi@ericsson.com>
 
        * unittests/string_view-selftests.c: Define GNULIB_NAMESPACE.

diff --git a/gdb/xtensa-linux-tdep.c b/gdb/xtensa-linux-tdep.c
index a9b30c73f7bf0c0362f9c5226dcaae1ccef2b633..b62085de2fcb76b7eddb2671fea10de4f62b99cf 100644 (file)
--- a/gdb/xtensa-linux-tdep.c
+++ b/gdb/xtensa-linux-tdep.c
@@ -18,6 +18,7 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "defs.h"
+#include "xtensa-tdep.h"
 #include "osabi.h"
 #include "linux-tdep.h"
 #include "solib-svr4.h"
@@ -97,6 +98,11 @@ xtensa_linux_gdb_signal_to_target (struct gdbarch *gdbarch,
 static void
 xtensa_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 {
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+  if (tdep->num_nopriv_regs < tdep->num_regs)
+    tdep->num_regs = tdep->num_nopriv_regs;
+
   linux_init_abi (info, gdbarch);
 
   set_solib_svr4_fetch_link_map_offsets

diff --git a/gdb/xtensa-tdep.c b/gdb/xtensa-tdep.c
index a1ecf5f56a429a28dae3470fe3e17f483a17235f..01f96165dc8d89a03cf6318ce5a46e853635a819 100644 (file)
--- a/gdb/xtensa-tdep.c
+++ b/gdb/xtensa-tdep.c
@@ -3145,16 +3145,12 @@ xtensa_derive_tdep (struct gdbarch_tdep *tdep)
        max_size = rmap->byte_size;
       if (rmap->mask != 0 && tdep->num_regs == 0)
        tdep->num_regs = n;
-      /* Find out out how to deal with priveleged registers.
-
-         if ((rmap->flags & XTENSA_REGISTER_FLAGS_PRIVILEGED) != 0
-              && tdep->num_nopriv_regs == 0)
-           tdep->num_nopriv_regs = n;
-      */
       if ((rmap->flags & XTENSA_REGISTER_FLAGS_PRIVILEGED) != 0
-         && tdep->num_regs == 0)
-       tdep->num_regs = n;
+         && tdep->num_nopriv_regs == 0)
+       tdep->num_nopriv_regs = n;
     }
+  if (tdep->num_regs == 0)
+    tdep->num_regs = tdep->num_nopriv_regs;
 
   /* Number of pseudo registers.  */
   tdep->num_pseudo_regs = n - tdep->num_regs;