gdb: Support XSAVE layouts for the current host in the FreeBSD x86 targets.

Use the CPUID instruction to fetch the offsets of supported state
components.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

1 files changed, 10 insertions, 30 deletions

diff --git a/gdb/amd64-fbsd-nat.c b/gdb/amd64-fbsd-nat.c
index 43e83ff..5821d94 100644
--- a/gdb/amd64-fbsd-nat.c
+++ b/gdb/amd64-fbsd-nat.c
@@ -31,9 +31,9 @@
 
 #include "amd64-tdep.h"
 #include "amd64-fbsd-tdep.h"
+#include "i387-tdep.h"
 #include "amd64-nat.h"
 #include "x86-nat.h"
-#include "gdbsupport/x86-xstate.h"
 #include "x86-fbsd-nat.h"
 
 class amd64_fbsd_nat_target final : public x86_fbsd_nat_target
@@ -47,10 +47,6 @@ public:
 
 static amd64_fbsd_nat_target the_amd64_fbsd_nat_target;
 
-#ifdef PT_GETXSTATE_INFO
-static size_t xsave_len;
-#endif
-
 /* This is a layout of the amd64 'struct reg' but with i386
    registers.  */
 
@@ -146,9 +142,9 @@ amd64_fbsd_nat_target::fetch_registers (struct regcache *regcache, int regnum)
      fetching the FPU/XSAVE state unnecessarily.  */
 
 #ifdef PT_GETXSTATE_INFO
-  if (xsave_len != 0)
+  if (m_xsave_info.xsave_len != 0)
     {
-      void *xstateregs = alloca (xsave_len);
+      void *xstateregs = alloca (m_xsave_info.xsave_len);
 
       if (ptrace (PT_GETXSTATE, pid, (PTRACE_TYPE_ARG3) xstateregs, 0) == -1)
 	perror_with_name (_("Couldn't get extended state status"));
@@ -223,9 +219,9 @@ amd64_fbsd_nat_target::store_registers (struct regcache *regcache, int regnum)
      fetching the FPU/XSAVE state unnecessarily.  */
 
 #ifdef PT_GETXSTATE_INFO
-  if (xsave_len != 0)
+  if (m_xsave_info.xsave_len != 0)
     {
-      void *xstateregs = alloca (xsave_len);
+      void *xstateregs = alloca (m_xsave_info.xsave_len);
 
       if (ptrace (PT_GETXSTATE, pid, (PTRACE_TYPE_ARG3) xstateregs, 0) == -1)
 	perror_with_name (_("Couldn't get extended state status"));
@@ -233,7 +229,7 @@ amd64_fbsd_nat_target::store_registers (struct regcache *regcache, int regnum)
       amd64_collect_xsave (regcache, regnum, xstateregs, 0);
 
       if (ptrace (PT_SETXSTATE, pid, (PTRACE_TYPE_ARG3) xstateregs,
-		  xsave_len) == -1)
+		  m_xsave_info.xsave_len) == -1)
 	perror_with_name (_("Couldn't write extended state status"));
       return;
     }
@@ -303,10 +299,6 @@ amd64fbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
 const struct target_desc *
 amd64_fbsd_nat_target::read_description ()
 {
-#ifdef PT_GETXSTATE_INFO
-  static int xsave_probed;
-  static uint64_t xcr0;
-#endif
   struct reg regs;
   int is64;
 
@@ -318,25 +310,13 @@ amd64_fbsd_nat_target::read_description ()
     perror_with_name (_("Couldn't get registers"));
   is64 = (regs.r_cs == GSEL (GUCODE_SEL, SEL_UPL));
 #ifdef PT_GETXSTATE_INFO
-  if (!xsave_probed)
-    {
-      struct ptrace_xstate_info info;
-
-      if (ptrace (PT_GETXSTATE_INFO, inferior_ptid.pid (),
-		  (PTRACE_TYPE_ARG3) &info, sizeof (info)) == 0)
-	{
-	  xsave_len = info.xsave_len;
-	  xcr0 = info.xsave_mask;
-	}
-      xsave_probed = 1;
-    }
-
-  if (xsave_len != 0)
+  probe_xsave_layout (inferior_ptid.pid ());
+  if (m_xsave_info.xsave_len != 0)
     {
       if (is64)
-	return amd64_target_description (xcr0, true);
+	return amd64_target_description (m_xsave_info.xsave_mask, true);
       else
-	return i386_target_description (xcr0, true);
+	return i386_target_description (m_xsave_info.xsave_mask, true);
     }
 #endif
   if (is64)