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>

5 files changed, 62 insertions, 62 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)
diff --git a/gdb/configure.nat b/gdb/configure.nat
index aabcdef..b371ad8 100644
--- a/gdb/configure.nat
+++ b/gdb/configure.nat
@@ -166,7 +166,8 @@ case ${gdb_host} in
 	    i386)
 		# Host: FreeBSD/i386
 		NATDEPFILES="${NATDEPFILES} x86-nat.o nat/x86-dregs.o \
-		x86-bsd-nat.o x86-fbsd-nat.o i386-fbsd-nat.o bsd-kvm.o"
+		nat/x86-xstate.o x86-bsd-nat.o x86-fbsd-nat.o i386-fbsd-nat.o \
+		bsd-kvm.o"
 		;;
 	    mips)
 		# Host: FreeBSD/mips
@@ -195,7 +196,7 @@ case ${gdb_host} in
 		# Host: FreeBSD/amd64
 		NATDEPFILES="${NATDEPFILES} amd64-nat.o \
 		amd64-fbsd-nat.o bsd-kvm.o x86-nat.o nat/x86-dregs.o \
-		x86-bsd-nat.o x86-fbsd-nat.o"
+		nat/x86-xstate.o x86-bsd-nat.o x86-fbsd-nat.o"
 		;;
 	esac
 	;;
diff --git a/gdb/i386-fbsd-nat.c b/gdb/i386-fbsd-nat.c
index a2255c3..e2c0e61 100644
--- a/gdb/i386-fbsd-nat.c
+++ b/gdb/i386-fbsd-nat.c
@@ -31,7 +31,6 @@
 #include "i386-fbsd-tdep.h"
 #include "i387-tdep.h"
 #include "x86-nat.h"
-#include "gdbsupport/x86-xstate.h"
 #include "x86-fbsd-nat.h"
 
 class i386_fbsd_nat_target final : public x86_fbsd_nat_target
@@ -47,10 +46,6 @@ public:
 
 static i386_fbsd_nat_target the_i386_fbsd_nat_target;
 
-#ifdef PT_GETXSTATE_INFO
-static size_t xsave_len;
-#endif
-
 static int have_ptrace_xmmregs;
 
 /* Fetch register REGNUM from the inferior.  If REGNUM is -1, do this
@@ -102,9 +97,9 @@ i386_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"));
@@ -181,17 +176,17 @@ i386_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"));
 
       i387_collect_xsave (regcache, regnum, xstateregs, 0);
 
-      if (ptrace (PT_SETXSTATE, pid, (PTRACE_TYPE_ARG3) xstateregs, xsave_len)
-	  == -1)
+      if (ptrace (PT_SETXSTATE, pid, (PTRACE_TYPE_ARG3) xstateregs,
+		  m_xsave_info.xsave_len) == -1)
 	perror_with_name (_("Couldn't write extended state status"));
       return;
     }
@@ -309,31 +304,15 @@ i386fbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
 const struct target_desc *
 i386_fbsd_nat_target::read_description ()
 {
-#ifdef PT_GETXSTATE_INFO
-  static int xsave_probed;
-  static uint64_t xcr0;
-#endif
   static int xmm_probed;
 
   if (inferior_ptid == null_ptid)
     return this->beneath ()->read_description ();
 
 #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)
-    return i386_target_description (xcr0, true);
+  probe_xsave_layout (inferior_ptid.pid ());
+  if (m_xsave_info.xsave_len != 0)
+    return i386_target_description (m_xsave_info.xsave_mask, true);
 #endif
 
   if (!xmm_probed)
diff --git a/gdb/x86-fbsd-nat.c b/gdb/x86-fbsd-nat.c
index 5d1c9fc..240e228 100644
--- a/gdb/x86-fbsd-nat.c
+++ b/gdb/x86-fbsd-nat.c
@@ -19,6 +19,9 @@
 
 #include "defs.h"
 #include "x86-fbsd-nat.h"
+#ifdef PT_GETXSTATE_INFO
+#include "nat/x86-xstate.h"
+#endif
 
 /* Implement the virtual fbsd_nat_target::low_new_fork method.  */
 
@@ -43,3 +46,21 @@ x86_fbsd_nat_target::low_new_fork (ptid_t parent, pid_t child)
   child_state = x86_debug_reg_state (child);
   *child_state = *parent_state;
 }
+
+#ifdef PT_GETXSTATE_INFO
+void
+x86_fbsd_nat_target::probe_xsave_layout (pid_t pid)
+{
+  if (m_xsave_probed)
+    return;
+
+  m_xsave_probed = true;
+
+  if (ptrace (PT_GETXSTATE_INFO, pid, (PTRACE_TYPE_ARG3) &m_xsave_info,
+	      sizeof (m_xsave_info)) != 0)
+    return;
+  if (m_xsave_info.xsave_len != 0)
+    m_xsave_layout = x86_fetch_xsave_layout (m_xsave_info.xsave_mask,
+					     m_xsave_info.xsave_len);
+}
+#endif
diff --git a/gdb/x86-fbsd-nat.h b/gdb/x86-fbsd-nat.h
index a424323..723bb6c 100644
--- a/gdb/x86-fbsd-nat.h
+++ b/gdb/x86-fbsd-nat.h
@@ -20,6 +20,11 @@
 #ifndef X86_FBSD_NAT_H
 #define X86_FBSD_NAT_H
 
+#include <sys/ptrace.h>
+
+#ifdef PT_GETXSTATE_INFO
+#include "gdbsupport/x86-xstate.h"
+#endif
 #include "fbsd-nat.h"
 #include "x86-bsd-nat.h"
 
@@ -32,6 +37,20 @@ public:
   { return true; }
 
   void low_new_fork (ptid_t parent, pid_t child) override;
+
+#ifdef PT_GETXSTATE_INFO
+  x86_xsave_layout fetch_x86_xsave_layout () override
+  { return m_xsave_layout; }
+
+protected:
+  void probe_xsave_layout (pid_t pid);
+
+  struct ptrace_xstate_info m_xsave_info;
+  x86_xsave_layout m_xsave_layout;
+
+private:
+  bool m_xsave_probed;
+#endif
 };
 
 #endif /* x86-bsd-nat.h */