From 239b6d10954b18ce089e9c3a667e7f2df3655476 Mon Sep 17 00:00:00 2001
From: Walfred Tedeschi <walfred.tedeschi@intel.com>
Date: Fri, 27 Jan 2017 15:19:12 +0100
Subject: [PATCH] gdbserver-amd64: add
 HAVE_STRUCT_USER_REGS_STRUCT_(GS|FS)_BASE for gdbserver.

The macros mentioned in the title were set only for GDB. In gdbserver they
were not set until now.  To align the code in GDB and gdbserver these macros
are also added into gdbserver, enabling read and write of gs_base and fs_base
registers from the system in new and old kernels.

2017-01-27  Walfred Tedeschi  <walfred.tedeschi@intel.com>

gdb/gdbserver/ChangeLog:

    	* configure.ac: Check if the fs_base and gs_base members of
    	`struct user_regs_struct' exist.
    	* config.in: Regenerated.
    	* configure: Likewise.
---
 gdb/gdbserver/ChangeLog    |  7 +++++++
 gdb/gdbserver/config.in    |  6 ++++++
 gdb/gdbserver/configure    | 26 ++++++++++++++++++++++++++
 gdb/gdbserver/configure.ac |  7 +++++++
 4 files changed, 46 insertions(+)

diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index d3fba9bfec6..79fe2f9703b 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,3 +1,10 @@
+2017-01-27  Walfred Tedeschi  <walfred.tedeschi@intel.com>
+
+	* configure.ac: Check if the fs_base and gs_base members of
+	`struct user_regs_struct' exist.
+	* config.in: Regenerated.
+	* configure: Likewise.
+
 2017-01-09  Antoine Tremblay  <antoine.tremblay@ericsson.com>
 
 	* linux-aarch32-low.c (arm_breakpoint_kind_from_pc): Use
diff --git a/gdb/gdbserver/config.in b/gdb/gdbserver/config.in
index b721ea83cf1..34a74434338 100644
--- a/gdb/gdbserver/config.in
+++ b/gdb/gdbserver/config.in
@@ -238,6 +238,12 @@
 /* Define to 1 if `struct stat' is a member of `st_blocks'. */
 #undef HAVE_STRUCT_STAT_ST_BLOCKS
 
+/* Define to 1 if `struct user_regs_struct' is a member of `fs_base'. */
+#undef HAVE_STRUCT_USER_REGS_STRUCT_FS_BASE
+
+/* Define to 1 if `struct user_regs_struct' is a member of `gs_base'. */
+#undef HAVE_STRUCT_USER_REGS_STRUCT_GS_BASE
+
 /* Define to 1 if the target supports __sync_*_compare_and_swap */
 #undef HAVE_SYNC_BUILTINS
 
diff --git a/gdb/gdbserver/configure b/gdb/gdbserver/configure
index 53c26f39f43..6ae486539f4 100755
--- a/gdb/gdbserver/configure
+++ b/gdb/gdbserver/configure
@@ -7498,6 +7498,32 @@ _ACEOF
 fi
 
 
+# See if <sys/user.h> supports the %fs_base and %gs_base amd64 segment
+# registers.  Older amd64 Linux's don't have the fs_base and gs_base
+# members of `struct user_regs_struct'.
+ac_fn_c_check_member "$LINENO" "struct user_regs_struct" "fs_base" "ac_cv_member_struct_user_regs_struct_fs_base" "#include <sys/user.h>
+"
+if test "x$ac_cv_member_struct_user_regs_struct_fs_base" = x""yes; then :
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_STRUCT_USER_REGS_STRUCT_FS_BASE 1
+_ACEOF
+
+
+fi
+ac_fn_c_check_member "$LINENO" "struct user_regs_struct" "gs_base" "ac_cv_member_struct_user_regs_struct_gs_base" "#include <sys/user.h>
+"
+if test "x$ac_cv_member_struct_user_regs_struct_gs_base" = x""yes; then :
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_STRUCT_USER_REGS_STRUCT_GS_BASE 1
+_ACEOF
+
+
+fi
+
+
+
 ac_fn_c_check_type "$LINENO" "socklen_t" "ac_cv_type_socklen_t" "#include <sys/types.h>
 #include <sys/socket.h>
 
diff --git a/gdb/gdbserver/configure.ac b/gdb/gdbserver/configure.ac
index d013c219cc7..4ea7913c981 100644
--- a/gdb/gdbserver/configure.ac
+++ b/gdb/gdbserver/configure.ac
@@ -163,6 +163,13 @@ AC_CHECK_DECLS([strerror, perror, vasprintf, vsnprintf])
 
 AC_CHECK_MEMBERS([struct stat.st_blocks, struct stat.st_blksize])
 
+# See if <sys/user.h> supports the %fs_base and %gs_bas amd64 segment registers.
+# Older amd64 Linux's don't have the fs_base and gs_base members of
+# `struct user_regs_struct'.
+AC_CHECK_MEMBERS([struct user_regs_struct.fs_base, struct user_regs_struct.gs_base],
+		 [], [], [#include <sys/user.h>])
+
+
 AC_CHECK_TYPES(socklen_t, [], [],
 [#include <sys/types.h>
 #include <sys/socket.h>
-- 
2.30.2