[binutils-gdb] gdb: xtensa: handle privileged registers

[Max Filippov <jcmvbkbc at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=37d9e0623102352e0ae27c311760a9e6569ae5e0

commit 37d9e0623102352e0ae27c311760a9e6569ae5e0
Author: Max Filippov <jcmvbkbc@gmail.com>
Date:   Wed Apr 25 11:55:56 2018 -0700

    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:
---
 gdb/ChangeLog           |  9 +++++++++
 gdb/xtensa-linux-tdep.c |  6 ++++++
 gdb/xtensa-tdep.c       | 12 ++++--------
 3 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index a1059aef..728ed8c 100644
--- 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 a9b30c7..b62085d 100644
--- 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 a1ecf5f..01f9616 100644
--- 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;