Support fs_base and gs_base on FreeBSD/i386.

The i386 BSD native target uses the same ptrace operations
(PT_[GS]ET[FG]SBASE) as the amd64 BSD native target to fetch and store
the registers.

The amd64 BSD native now uses 'tdep->fsbase_regnum' instead of
hardcoding AMD64_FSBASE_REGNUM and AMD64_GSBASE_REGNUM to support
32-bit targets.  In addition, the store operations explicitly zero the
new register value before fetching it from the register cache to
ensure 32-bit values are zero-extended.

gdb/ChangeLog:

	* amd64-bsd-nat.c (amd64bsd_fetch_inferior_registers): Use
	tdep->fsbase_regnum instead of constants for fs_base and gs_base.
	(amd64bsd_store_inferior_registers): Likewise.
	* amd64-fbsd-nat.c (amd64_fbsd_nat_target::read_description):
	Enable segment base registers.
	* i386-bsd-nat.c (i386bsd_fetch_inferior_registers): Use
	PT_GETFSBASE and PT_GETGSBASE.
	(i386bsd_store_inferior_registers): Use PT_SETFSBASE and
	PT_SETGSBASE.
	* i386-fbsd-nat.c (i386_fbsd_nat_target::read_description): Enable
	segment base registers.
	* i386-fbsd-tdep.c (i386fbsd_core_read_description): Likewise.

1 files changed, 1 insertions, 1 deletions

diff --git a/gdb/i386-fbsd-tdep.c b/gdb/i386-fbsd-tdep.c
index 2f28bad..ac57e73 100644
--- a/gdb/i386-fbsd-tdep.c
+++ b/gdb/i386-fbsd-tdep.c
@@ -267,7 +267,7 @@ i386fbsd_core_read_description (struct gdbarch *gdbarch,
 				struct target_ops *target,
 				bfd *abfd)
 {
-  return i386_target_description (i386fbsd_core_read_xcr0 (abfd), false);
+  return i386_target_description (i386fbsd_core_read_xcr0 (abfd), true);
 }
 
 /* Similar to i386_supply_fpregset, but use XSAVE extended state.  */