Improve support for XSAVE with debuggers.

- Dump an NT_X86_XSTATE note if XSAVE is in use. This note is designed
  to match what Linux does in that 1) it dumps the entire XSAVE area
  including the fxsave state, and 2) it stashes a copy of the current
  xsave mask in the unused padding between the fxsave state and the
  xstate header at the same location used by Linux.
- Teach readelf() to recognize NT_X86_XSTATE notes.
- Change PT_GET/SETXSTATE to take the entire XSAVE state instead of
  only the extra portion. This avoids having to always make two
  ptrace() calls to get or set the full XSAVE state.
- Add a PT_GET_XSTATE_INFO which returns the length of the current
  XSTATE save area (so the size of the buffer needed for PT_GETXSTATE)
  and the current XSAVE mask (%xcr0).

Differential Revision:	https://reviews.freebsd.org/D1193
Reviewed by:	kib
MFC after:	2 weeks

2 files changed, 3 insertions, 0 deletions

diff --git a/contrib/binutils/binutils/readelf.c b/contrib/binutils/binutils/readelf.c
index aafd8d4502e9..09f4062a4d9f 100644
--- a/contrib/binutils/binutils/readelf.c
+++ b/contrib/binutils/binutils/readelf.c
@@ -9159,6 +9159,8 @@ get_freebsd_note_type (unsigned e_type)
 	return _("NT_PROCSTAT_PSSTRINGS (ps_strings data)");
       case NT_PROCSTAT_AUXV:
 	return _("NT_PROCSTAT_AUXV (auxv data)");
+      case NT_X86_XSTATE:
+	return _("NT_X86_XSTATE (x86 XSAVE extended state)");
       default:
 	return get_note_type(e_type);
       }
diff --git a/contrib/binutils/include/elf/common.h b/contrib/binutils/include/elf/common.h
index d4d9d7b0cc7a..157922af3f0b 100644
--- a/contrib/binutils/include/elf/common.h
+++ b/contrib/binutils/include/elf/common.h
@@ -414,6 +414,7 @@
 #define NT_PROCSTAT_OSREL	14
 #define NT_PROCSTAT_PSSTRINGS	15
 #define NT_PROCSTAT_AUXV	16
+#define	NT_X86_XSTATE		0x202
 
 
 /* Note segments for core files on NetBSD systems.  Note name