+/* Generic GNU/Linux target using traditional ptrace register access.
+
+ Copyright (C) 1988-2018 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include "defs.h"
+#include "linux-nat-trad.h"
+
+#include "nat/gdb_ptrace.h"
+#include "inf-ptrace.h"
+
+/* Pointer to a function that returns the offset within the user area
+ where a particular register is stored. */
+static CORE_ADDR (*inf_ptrace_register_u_offset)(struct gdbarch *, int, int);
+
+/* Fetch register REGNUM from the inferior. */
+
+static void
+inf_ptrace_fetch_register (struct regcache *regcache, int regnum)
+{
+ struct gdbarch *gdbarch = regcache->arch ();
+ CORE_ADDR addr;
+ size_t size;
+ PTRACE_TYPE_RET *buf;
+ pid_t pid;
+ int i;
+
+ /* This isn't really an address, but ptrace thinks of it as one. */
+ addr = inf_ptrace_register_u_offset (gdbarch, regnum, 0);
+ if (addr == (CORE_ADDR)-1
+ || gdbarch_cannot_fetch_register (gdbarch, regnum))
+ {
+ regcache_raw_supply (regcache, regnum, NULL);
+ return;
+ }
+
+ pid = get_ptrace_pid (regcache_get_ptid (regcache));
+
+ size = register_size (gdbarch, regnum);
+ gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0);
+ buf = (PTRACE_TYPE_RET *) alloca (size);
+
+ /* Read the register contents from the inferior a chunk at a time. */
+ for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++)
+ {
+ errno = 0;
+ buf[i] = ptrace (PT_READ_U, pid, (PTRACE_TYPE_ARG3)(uintptr_t)addr, 0);
+ if (errno != 0)
+ error (_("Couldn't read register %s (#%d): %s."),
+ gdbarch_register_name (gdbarch, regnum),
+ regnum, safe_strerror (errno));
+
+ addr += sizeof (PTRACE_TYPE_RET);
+ }
+ regcache_raw_supply (regcache, regnum, buf);
+}
+
+/* Fetch register REGNUM from the inferior. If REGNUM is -1, do this
+ for all registers. */
+
+static void
+inf_ptrace_fetch_registers (struct target_ops *ops,
+ struct regcache *regcache, int regnum)
+{
+ if (regnum == -1)
+ for (regnum = 0;
+ regnum < gdbarch_num_regs (regcache->arch ());
+ regnum++)
+ inf_ptrace_fetch_register (regcache, regnum);
+ else
+ inf_ptrace_fetch_register (regcache, regnum);
+}
+
+/* Store register REGNUM into the inferior. */
+
+static void
+inf_ptrace_store_register (const struct regcache *regcache, int regnum)
+{
+ struct gdbarch *gdbarch = regcache->arch ();
+ CORE_ADDR addr;
+ size_t size;
+ PTRACE_TYPE_RET *buf;
+ pid_t pid;
+ int i;
+
+ /* This isn't really an address, but ptrace thinks of it as one. */
+ addr = inf_ptrace_register_u_offset (gdbarch, regnum, 1);
+ if (addr == (CORE_ADDR)-1
+ || gdbarch_cannot_store_register (gdbarch, regnum))
+ return;
+
+ pid = get_ptrace_pid (regcache_get_ptid (regcache));
+
+ size = register_size (gdbarch, regnum);
+ gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0);
+ buf = (PTRACE_TYPE_RET *) alloca (size);
+
+ /* Write the register contents into the inferior a chunk at a time. */
+ regcache_raw_collect (regcache, regnum, buf);
+ for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++)
+ {
+ errno = 0;
+ ptrace (PT_WRITE_U, pid, (PTRACE_TYPE_ARG3)(uintptr_t)addr, buf[i]);
+ if (errno != 0)
+ error (_("Couldn't write register %s (#%d): %s."),
+ gdbarch_register_name (gdbarch, regnum),
+ regnum, safe_strerror (errno));
+
+ addr += sizeof (PTRACE_TYPE_RET);
+ }
+}
+
+/* Store register REGNUM back into the inferior. If REGNUM is -1, do
+ this for all registers. */
+
+static void
+inf_ptrace_store_registers (struct target_ops *ops,
+ struct regcache *regcache, int regnum)
+{
+ if (regnum == -1)
+ for (regnum = 0;
+ regnum < gdbarch_num_regs (regcache->arch ());
+ regnum++)
+ inf_ptrace_store_register (regcache, regnum);
+ else
+ inf_ptrace_store_register (regcache, regnum);
+}
+
+/* Create a "traditional" Linux/ptrace target. REGISTER_U_OFFSET
+ should be a function returning the offset within the user area
+ where a particular register is stored. */
+
+struct target_ops *
+linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int))
+{
+ struct target_ops *t = inf_ptrace_target();
+
+ gdb_assert (register_u_offset);
+ inf_ptrace_register_u_offset = register_u_offset;
+ t->to_fetch_registers = inf_ptrace_fetch_registers;
+ t->to_store_registers = inf_ptrace_store_registers;
+
+ linux_target_install_ops (t);
+
+ return t;
+}