Fix extracting tags from PCC and CSP

The tags for PCC/CSP are stored in the order of struct user_morello_state.

Make sure we account for that when extracting the tags.

gdb/ChangeLog:

2021-03-17  Luis Machado  <luis.machado@arm.com>

	* aarch64-tdep.c (aarch64_register_tag): Handle PCC/CSP tag
	extraction.

diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
index 14531b27009cbce0f6fcb3ef998c3f43b43697ca..e4ac51a00ab999bea7e9f13ad0d9e961b287cf27 100644 (file)
--- a/gdb/aarch64-tdep.c
+++ b/gdb/aarch64-tdep.c
@@ -4189,6 +4189,16 @@ aarch64_register_tag (struct gdbarch *gdbarch,
       regnum > tdep->cap_reg_last - 2)
     return false;
 
+  /* The CSP/PCC tags are swapped in the tag_map because the ordering of CSP/PCC
+     in struct user_morello_state is different from GDB's register description.
+
+     Make sure we account for that when extracting the tag from those
+     registers.  */
+  if (regnum == tdep->cap_reg_pcc)
+    regnum = tdep->cap_reg_csp;
+  else if (regnum == tdep->cap_reg_csp)
+    regnum = tdep->cap_reg_pcc;
+
   /* Find the proper bit within the tag_map.  */
   int shift = regnum - tdep->cap_reg_base;
   ULONGEST tag_map = 0;