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561 lines
16 KiB
C
561 lines
16 KiB
C
/* BSD user-level threads support.
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Copyright (C) 2005-2018 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "gdbcore.h"
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#include "gdbthread.h"
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#include "inferior.h"
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#include "objfiles.h"
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#include "observer.h"
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#include "regcache.h"
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#include "solib.h"
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#include "solist.h"
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#include "symfile.h"
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#include "target.h"
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#include "gdb_obstack.h"
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#include "bsd-uthread.h"
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/* HACK: Save the bsd_uthreads ops returned by bsd_uthread_target. */
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static struct target_ops *bsd_uthread_ops_hack;
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/* Architecture-specific operations. */
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/* Per-architecture data key. */
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static struct gdbarch_data *bsd_uthread_data;
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struct bsd_uthread_ops
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{
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/* Supply registers for an inactive thread to a register cache. */
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void (*supply_uthread)(struct regcache *, int, CORE_ADDR);
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/* Collect registers for an inactive thread from a register cache. */
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void (*collect_uthread)(const struct regcache *, int, CORE_ADDR);
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};
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static void *
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bsd_uthread_init (struct obstack *obstack)
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{
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struct bsd_uthread_ops *ops;
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ops = OBSTACK_ZALLOC (obstack, struct bsd_uthread_ops);
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return ops;
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}
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/* Set the function that supplies registers from an inactive thread
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for architecture GDBARCH to SUPPLY_UTHREAD. */
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void
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bsd_uthread_set_supply_uthread (struct gdbarch *gdbarch,
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void (*supply_uthread) (struct regcache *,
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int, CORE_ADDR))
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{
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struct bsd_uthread_ops *ops
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= (struct bsd_uthread_ops *) gdbarch_data (gdbarch, bsd_uthread_data);
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ops->supply_uthread = supply_uthread;
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}
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/* Set the function that collects registers for an inactive thread for
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architecture GDBARCH to SUPPLY_UTHREAD. */
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void
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bsd_uthread_set_collect_uthread (struct gdbarch *gdbarch,
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void (*collect_uthread) (const struct regcache *,
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int, CORE_ADDR))
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{
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struct bsd_uthread_ops *ops
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= (struct bsd_uthread_ops *) gdbarch_data (gdbarch, bsd_uthread_data);
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ops->collect_uthread = collect_uthread;
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}
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/* Magic number to help recognize a valid thread structure. */
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#define BSD_UTHREAD_PTHREAD_MAGIC 0xd09ba115
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/* Check whether the thread structure at ADDR is valid. */
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static void
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bsd_uthread_check_magic (CORE_ADDR addr)
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{
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enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
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ULONGEST magic = read_memory_unsigned_integer (addr, 4, byte_order);
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if (magic != BSD_UTHREAD_PTHREAD_MAGIC)
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error (_("Bad magic"));
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}
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/* Thread states. */
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#define BSD_UTHREAD_PS_RUNNING 0
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#define BSD_UTHREAD_PS_DEAD 18
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/* Address of the pointer to the thread structure for the running
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thread. */
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static CORE_ADDR bsd_uthread_thread_run_addr;
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/* Address of the list of all threads. */
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static CORE_ADDR bsd_uthread_thread_list_addr;
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/* Offsets of various "interesting" bits in the thread structure. */
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static int bsd_uthread_thread_state_offset = -1;
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static int bsd_uthread_thread_next_offset = -1;
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static int bsd_uthread_thread_ctx_offset;
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/* Name of shared threads library. */
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static const char *bsd_uthread_solib_name;
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/* Non-zero if the thread startum implemented by this module is active. */
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static int bsd_uthread_active;
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static CORE_ADDR
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bsd_uthread_lookup_address (const char *name, struct objfile *objfile)
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{
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struct bound_minimal_symbol sym;
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sym = lookup_minimal_symbol (name, NULL, objfile);
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if (sym.minsym)
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return BMSYMBOL_VALUE_ADDRESS (sym);
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return 0;
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}
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static int
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bsd_uthread_lookup_offset (const char *name, struct objfile *objfile)
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{
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enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
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CORE_ADDR addr;
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addr = bsd_uthread_lookup_address (name, objfile);
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if (addr == 0)
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return 0;
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return read_memory_unsigned_integer (addr, 4, byte_order);
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}
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static CORE_ADDR
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bsd_uthread_read_memory_address (CORE_ADDR addr)
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{
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struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
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return read_memory_typed_address (addr, ptr_type);
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}
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/* If OBJFILE contains the symbols corresponding to one of the
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supported user-level threads libraries, activate the thread stratum
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implemented by this module. */
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static int
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bsd_uthread_activate (struct objfile *objfile)
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{
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struct gdbarch *gdbarch = target_gdbarch ();
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struct bsd_uthread_ops *ops
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= (struct bsd_uthread_ops *) gdbarch_data (gdbarch, bsd_uthread_data);
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/* Skip if the thread stratum has already been activated. */
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if (bsd_uthread_active)
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return 0;
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/* There's no point in enabling this module if no
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architecture-specific operations are provided. */
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if (!ops->supply_uthread)
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return 0;
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bsd_uthread_thread_run_addr =
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bsd_uthread_lookup_address ("_thread_run", objfile);
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if (bsd_uthread_thread_run_addr == 0)
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return 0;
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bsd_uthread_thread_list_addr =
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bsd_uthread_lookup_address ("_thread_list", objfile);
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if (bsd_uthread_thread_list_addr == 0)
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return 0;
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bsd_uthread_thread_state_offset =
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bsd_uthread_lookup_offset ("_thread_state_offset", objfile);
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if (bsd_uthread_thread_state_offset == 0)
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return 0;
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bsd_uthread_thread_next_offset =
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bsd_uthread_lookup_offset ("_thread_next_offset", objfile);
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if (bsd_uthread_thread_next_offset == 0)
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return 0;
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bsd_uthread_thread_ctx_offset =
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bsd_uthread_lookup_offset ("_thread_ctx_offset", objfile);
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push_target (bsd_uthread_ops_hack);
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bsd_uthread_active = 1;
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return 1;
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}
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/* Cleanup due to deactivation. */
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static void
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bsd_uthread_close (struct target_ops *self)
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{
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bsd_uthread_active = 0;
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bsd_uthread_thread_run_addr = 0;
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bsd_uthread_thread_list_addr = 0;
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bsd_uthread_thread_state_offset = 0;
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bsd_uthread_thread_next_offset = 0;
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bsd_uthread_thread_ctx_offset = 0;
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bsd_uthread_solib_name = NULL;
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}
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/* Deactivate the thread stratum implemented by this module. */
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static void
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bsd_uthread_deactivate (void)
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{
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/* Skip if the thread stratum has already been deactivated. */
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if (!bsd_uthread_active)
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return;
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unpush_target (bsd_uthread_ops_hack);
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}
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static void
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bsd_uthread_inferior_created (struct target_ops *ops, int from_tty)
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{
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bsd_uthread_activate (NULL);
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}
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/* Likely candidates for the threads library. */
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static const char *bsd_uthread_solib_names[] =
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{
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"/usr/lib/libc_r.so", /* FreeBSD */
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"/usr/lib/libpthread.so", /* OpenBSD */
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NULL
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};
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static void
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bsd_uthread_solib_loaded (struct so_list *so)
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{
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const char **names = bsd_uthread_solib_names;
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for (names = bsd_uthread_solib_names; *names; names++)
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{
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if (startswith (so->so_original_name, *names))
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{
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solib_read_symbols (so, 0);
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if (bsd_uthread_activate (so->objfile))
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{
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bsd_uthread_solib_name = so->so_original_name;
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return;
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}
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}
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}
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}
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static void
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bsd_uthread_solib_unloaded (struct so_list *so)
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{
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if (!bsd_uthread_solib_name)
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return;
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if (strcmp (so->so_original_name, bsd_uthread_solib_name) == 0)
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bsd_uthread_deactivate ();
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}
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static void
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bsd_uthread_mourn_inferior (struct target_ops *ops)
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{
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struct target_ops *beneath = find_target_beneath (ops);
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beneath->to_mourn_inferior (beneath);
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bsd_uthread_deactivate ();
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}
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static void
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bsd_uthread_fetch_registers (struct target_ops *ops,
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struct regcache *regcache, int regnum)
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{
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struct gdbarch *gdbarch = regcache->arch ();
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struct bsd_uthread_ops *uthread_ops
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= (struct bsd_uthread_ops *) gdbarch_data (gdbarch, bsd_uthread_data);
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ptid_t ptid = regcache_get_ptid (regcache);
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CORE_ADDR addr = ptid_get_tid (ptid);
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struct target_ops *beneath = find_target_beneath (ops);
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CORE_ADDR active_addr;
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scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
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/* We are doing operations (e.g. reading memory) that rely on
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inferior_ptid. */
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inferior_ptid = ptid;
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/* Always fetch the appropriate registers from the layer beneath. */
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beneath->to_fetch_registers (beneath, regcache, regnum);
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/* FIXME: That might have gotten us more than we asked for. Make
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sure we overwrite all relevant registers with values from the
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thread structure. This can go once we fix the underlying target. */
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regnum = -1;
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active_addr = bsd_uthread_read_memory_address (bsd_uthread_thread_run_addr);
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if (addr != 0 && addr != active_addr)
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{
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bsd_uthread_check_magic (addr);
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uthread_ops->supply_uthread (regcache, regnum,
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addr + bsd_uthread_thread_ctx_offset);
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}
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}
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static void
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bsd_uthread_store_registers (struct target_ops *ops,
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struct regcache *regcache, int regnum)
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{
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struct gdbarch *gdbarch = regcache->arch ();
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struct bsd_uthread_ops *uthread_ops
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= (struct bsd_uthread_ops *) gdbarch_data (gdbarch, bsd_uthread_data);
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struct target_ops *beneath = find_target_beneath (ops);
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ptid_t ptid = regcache_get_ptid (regcache);
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CORE_ADDR addr = ptid_get_tid (ptid);
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CORE_ADDR active_addr;
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scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
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/* We are doing operations (e.g. reading memory) that rely on
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inferior_ptid. */
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inferior_ptid = ptid;
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active_addr = bsd_uthread_read_memory_address (bsd_uthread_thread_run_addr);
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if (addr != 0 && addr != active_addr)
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{
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bsd_uthread_check_magic (addr);
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uthread_ops->collect_uthread (regcache, regnum,
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addr + bsd_uthread_thread_ctx_offset);
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}
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else
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{
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/* Updating the thread that is currently running; pass the
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request to the layer beneath. */
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beneath->to_store_registers (beneath, regcache, regnum);
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}
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}
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static ptid_t
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bsd_uthread_wait (struct target_ops *ops,
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ptid_t ptid, struct target_waitstatus *status, int options)
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{
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enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
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CORE_ADDR addr;
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struct target_ops *beneath = find_target_beneath (ops);
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/* Pass the request to the layer beneath. */
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ptid = beneath->to_wait (beneath, ptid, status, options);
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/* If the process is no longer alive, there's no point in figuring
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out the thread ID. It will fail anyway. */
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if (status->kind == TARGET_WAITKIND_SIGNALLED
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|| status->kind == TARGET_WAITKIND_EXITED)
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return ptid;
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/* Fetch the corresponding thread ID, and augment the returned
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process ID with it. */
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addr = bsd_uthread_read_memory_address (bsd_uthread_thread_run_addr);
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if (addr != 0)
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{
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gdb_byte buf[4];
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/* FIXME: For executables linked statically with the threads
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library, we end up here before the program has actually been
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executed. In that case ADDR will be garbage since it has
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been read from the wrong virtual memory image. */
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if (target_read_memory (addr, buf, 4) == 0)
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{
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ULONGEST magic = extract_unsigned_integer (buf, 4, byte_order);
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if (magic == BSD_UTHREAD_PTHREAD_MAGIC)
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ptid = ptid_build (ptid_get_pid (ptid), 0, addr);
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}
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}
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/* If INFERIOR_PTID doesn't have a tid member yet, and we now have a
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ptid with tid set, then ptid is still the initial thread of
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the process. Notify GDB core about it. */
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if (ptid_get_tid (inferior_ptid) == 0
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&& ptid_get_tid (ptid) != 0 && !in_thread_list (ptid))
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thread_change_ptid (inferior_ptid, ptid);
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/* Don't let the core see a ptid without a corresponding thread. */
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if (!in_thread_list (ptid) || is_exited (ptid))
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add_thread (ptid);
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return ptid;
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}
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static void
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bsd_uthread_resume (struct target_ops *ops,
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ptid_t ptid, int step, enum gdb_signal sig)
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{
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/* Pass the request to the layer beneath. */
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struct target_ops *beneath = find_target_beneath (ops);
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beneath->to_resume (beneath, ptid, step, sig);
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}
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static int
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bsd_uthread_thread_alive (struct target_ops *ops, ptid_t ptid)
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{
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enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
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struct target_ops *beneath = find_target_beneath (ops);
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CORE_ADDR addr = ptid_get_tid (ptid);
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if (addr != 0)
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{
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int offset = bsd_uthread_thread_state_offset;
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ULONGEST state;
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bsd_uthread_check_magic (addr);
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state = read_memory_unsigned_integer (addr + offset, 4, byte_order);
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if (state == BSD_UTHREAD_PS_DEAD)
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return 0;
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}
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return beneath->to_thread_alive (beneath, ptid);
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}
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static void
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bsd_uthread_update_thread_list (struct target_ops *ops)
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{
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pid_t pid = ptid_get_pid (inferior_ptid);
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int offset = bsd_uthread_thread_next_offset;
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CORE_ADDR addr;
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prune_threads ();
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addr = bsd_uthread_read_memory_address (bsd_uthread_thread_list_addr);
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while (addr != 0)
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{
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ptid_t ptid = ptid_build (pid, 0, addr);
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if (!in_thread_list (ptid) || is_exited (ptid))
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{
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/* If INFERIOR_PTID doesn't have a tid member yet, then ptid
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is still the initial thread of the process. Notify GDB
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core about it. */
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if (ptid_get_tid (inferior_ptid) == 0)
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thread_change_ptid (inferior_ptid, ptid);
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else
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add_thread (ptid);
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}
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addr = bsd_uthread_read_memory_address (addr + offset);
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}
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}
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/* Possible states a thread can be in. */
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static const char *bsd_uthread_state[] =
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{
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"RUNNING",
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"SIGTHREAD",
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"MUTEX_WAIT",
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"COND_WAIT",
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"FDLR_WAIT",
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"FDLW_WAIT",
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"FDR_WAIT",
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"FDW_WAIT",
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"FILE_WAIT",
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"POLL_WAIT",
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"SELECT_WAIT",
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"SLEEP_WAIT",
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"WAIT_WAIT",
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"SIGSUSPEND",
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"SIGWAIT",
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"SPINBLOCK",
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"JOIN",
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"SUSPENDED",
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"DEAD",
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"DEADLOCK"
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};
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/* Return a string describing th state of the thread specified by
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INFO. */
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static const char *
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bsd_uthread_extra_thread_info (struct target_ops *self,
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struct thread_info *info)
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{
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enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
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CORE_ADDR addr = ptid_get_tid (info->ptid);
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if (addr != 0)
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{
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int offset = bsd_uthread_thread_state_offset;
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ULONGEST state;
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state = read_memory_unsigned_integer (addr + offset, 4, byte_order);
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if (state < ARRAY_SIZE (bsd_uthread_state))
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return bsd_uthread_state[state];
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}
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return NULL;
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}
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static const char *
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bsd_uthread_pid_to_str (struct target_ops *ops, ptid_t ptid)
|
||
{
|
||
if (ptid_get_tid (ptid) != 0)
|
||
{
|
||
static char buf[64];
|
||
|
||
xsnprintf (buf, sizeof buf, "process %d, thread 0x%lx",
|
||
ptid_get_pid (ptid), ptid_get_tid (ptid));
|
||
return buf;
|
||
}
|
||
|
||
return normal_pid_to_str (ptid);
|
||
}
|
||
|
||
static struct target_ops *
|
||
bsd_uthread_target (void)
|
||
{
|
||
struct target_ops *t = XCNEW (struct target_ops);
|
||
|
||
t->to_shortname = "bsd-uthreads";
|
||
t->to_longname = "BSD user-level threads";
|
||
t->to_doc = "BSD user-level threads";
|
||
t->to_close = bsd_uthread_close;
|
||
t->to_mourn_inferior = bsd_uthread_mourn_inferior;
|
||
t->to_fetch_registers = bsd_uthread_fetch_registers;
|
||
t->to_store_registers = bsd_uthread_store_registers;
|
||
t->to_wait = bsd_uthread_wait;
|
||
t->to_resume = bsd_uthread_resume;
|
||
t->to_thread_alive = bsd_uthread_thread_alive;
|
||
t->to_update_thread_list = bsd_uthread_update_thread_list;
|
||
t->to_extra_thread_info = bsd_uthread_extra_thread_info;
|
||
t->to_pid_to_str = bsd_uthread_pid_to_str;
|
||
t->to_stratum = thread_stratum;
|
||
t->to_magic = OPS_MAGIC;
|
||
bsd_uthread_ops_hack = t;
|
||
|
||
return t;
|
||
}
|
||
|
||
void
|
||
_initialize_bsd_uthread (void)
|
||
{
|
||
complete_target_initialization (bsd_uthread_target ());
|
||
|
||
bsd_uthread_data = gdbarch_data_register_pre_init (bsd_uthread_init);
|
||
|
||
observer_attach_inferior_created (bsd_uthread_inferior_created);
|
||
observer_attach_solib_loaded (bsd_uthread_solib_loaded);
|
||
observer_attach_solib_unloaded (bsd_uthread_solib_unloaded);
|
||
}
|