/* Low-level child interface to ptrace.
- Copyright (C) 1988-1996, 1998-2002, 2004-2012 Free Software
- Foundation, Inc.
+ Copyright (C) 1988-2017 Free Software Foundation, Inc.
This file is part of GDB.
#include "terminal.h"
#include "gdbcore.h"
#include "regcache.h"
-
-#include "gdb_assert.h"
-#include "gdb_string.h"
-#include "gdb_ptrace.h"
+#include "nat/gdb_ptrace.h"
#include "gdb_wait.h"
#include <signal.h>
#include "inf-ptrace.h"
#include "inf-child.h"
#include "gdbthread.h"
+#include "nat/fork-inferior.h"
+#include "utils.h"
\f
#ifdef PT_GET_PROCESS_STATE
+/* Target hook for follow_fork. On entry and at return inferior_ptid is
+ the ptid of the followed inferior. */
+
static int
-inf_ptrace_follow_fork (struct target_ops *ops, int follow_child)
+inf_ptrace_follow_fork (struct target_ops *ops, int follow_child,
+ int detach_fork)
{
- pid_t pid, fpid;
- ptrace_state_t pe;
-
- pid = ptid_get_pid (inferior_ptid);
-
- if (ptrace (PT_GET_PROCESS_STATE, pid,
- (PTRACE_TYPE_ARG3)&pe, sizeof pe) == -1)
- perror_with_name (("ptrace"));
-
- gdb_assert (pe.pe_report_event == PTRACE_FORK);
- fpid = pe.pe_other_pid;
-
- if (follow_child)
+ if (!follow_child)
{
- struct inferior *parent_inf, *child_inf;
- struct thread_info *tp;
-
- parent_inf = find_inferior_pid (pid);
-
- /* Add the child. */
- child_inf = add_inferior (fpid);
- child_inf->attach_flag = parent_inf->attach_flag;
- copy_terminal_info (child_inf, parent_inf);
- child_inf->pspace = parent_inf->pspace;
- child_inf->aspace = parent_inf->aspace;
-
- /* Before detaching from the parent, remove all breakpoints from
- it. */
- remove_breakpoints ();
-
- if (ptrace (PT_DETACH, pid, (PTRACE_TYPE_ARG3)1, 0) == -1)
- perror_with_name (("ptrace"));
+ struct thread_info *tp = inferior_thread ();
+ pid_t child_pid = ptid_get_pid (tp->pending_follow.value.related_pid);
- /* Switch inferior_ptid out of the parent's way. */
- inferior_ptid = pid_to_ptid (fpid);
-
- /* Delete the parent. */
- detach_inferior (pid);
-
- add_thread_silent (inferior_ptid);
- }
- else
- {
/* Breakpoints have already been detached from the child by
infrun.c. */
- if (ptrace (PT_DETACH, fpid, (PTRACE_TYPE_ARG3)1, 0) == -1)
+ if (ptrace (PT_DETACH, child_pid, (PTRACE_TYPE_ARG3)1, 0) == -1)
perror_with_name (("ptrace"));
}
return 0;
}
+static int
+inf_ptrace_insert_fork_catchpoint (struct target_ops *self, int pid)
+{
+ return 0;
+}
+
+static int
+inf_ptrace_remove_fork_catchpoint (struct target_ops *self, int pid)
+{
+ return 0;
+}
+
#endif /* PT_GET_PROCESS_STATE */
\f
inf_ptrace_me (void)
{
/* "Trace me, Dr. Memory!" */
- ptrace (PT_TRACE_ME, 0, (PTRACE_TYPE_ARG3)0, 0);
+ if (ptrace (PT_TRACE_ME, 0, (PTRACE_TYPE_ARG3) 0, 0) < 0)
+ trace_start_error_with_name ("ptrace");
}
/* Start a new inferior Unix child process. EXEC_FILE is the file to
static void
inf_ptrace_create_inferior (struct target_ops *ops,
- char *exec_file, char *allargs, char **env,
- int from_tty)
+ const char *exec_file, const std::string &allargs,
+ char **env, int from_tty)
{
- int pid;
+ pid_t pid;
+ ptid_t ptid;
/* Do not change either targets above or the same target if already present.
The reason is the target stack is shared across multiple inferiors. */
int ops_already_pushed = target_is_pushed (ops);
- struct cleanup *back_to = NULL;
+ struct cleanup *back_to = make_cleanup (null_cleanup, NULL);
if (! ops_already_pushed)
{
/* Clear possible core file with its process_stratum. */
push_target (ops);
- back_to = make_cleanup_unpush_target (ops);
+ make_cleanup_unpush_target (ops);
}
pid = fork_inferior (exec_file, allargs, env, inf_ptrace_me, NULL,
NULL, NULL, NULL);
- if (! ops_already_pushed)
- discard_cleanups (back_to);
+ ptid = pid_to_ptid (pid);
+ /* We have something that executes now. We'll be running through
+ the shell at this point (if startup-with-shell is true), but the
+ pid shouldn't change. */
+ add_thread_silent (ptid);
- /* START_INFERIOR_TRAPS_EXPECTED is defined in inferior.h, and will
- be 1 or 2 depending on whether we're starting without or with a
- shell. */
- startup_inferior (START_INFERIOR_TRAPS_EXPECTED);
+ discard_cleanups (back_to);
+
+ gdb_startup_inferior (pid, START_INFERIOR_TRAPS_EXPECTED);
/* On some targets, there must be some explicit actions taken after
the inferior has been started up. */
- target_post_startup_inferior (pid_to_ptid (pid));
+ target_post_startup_inferior (ptid);
}
#ifdef PT_GET_PROCESS_STATE
static void
-inf_ptrace_post_startup_inferior (ptid_t pid)
+inf_ptrace_post_startup_inferior (struct target_ops *self, ptid_t pid)
{
ptrace_event_t pe;
only report its exit status to its original parent. */
waitpid (ptid_get_pid (inferior_ptid), &status, 0);
- generic_mourn_inferior ();
-
- if (!have_inferiors ())
- unpush_target (ops);
+ inf_child_mourn_inferior (ops);
}
/* Attach to the process specified by ARGS. If FROM_TTY is non-zero,
be chatty about it. */
static void
-inf_ptrace_attach (struct target_ops *ops, char *args, int from_tty)
+inf_ptrace_attach (struct target_ops *ops, const char *args, int from_tty)
{
char *exec_file;
pid_t pid;
/* Do not change either targets above or the same target if already present.
The reason is the target stack is shared across multiple inferiors. */
int ops_already_pushed = target_is_pushed (ops);
- struct cleanup *back_to = NULL;
+ struct cleanup *back_to = make_cleanup (null_cleanup, NULL);
pid = parse_pid_to_attach (args);
/* target_pid_to_str already uses the target. Also clear possible core
file with its process_stratum. */
push_target (ops);
- back_to = make_cleanup_unpush_target (ops);
+ make_cleanup_unpush_target (ops);
}
if (from_tty)
target, it should decorate the ptid later with more info. */
add_thread_silent (inferior_ptid);
- if (! ops_already_pushed)
- discard_cleanups (back_to);
+ discard_cleanups (back_to);
}
#ifdef PT_GET_PROCESS_STATE
static void
-inf_ptrace_post_attach (int pid)
+inf_ptrace_post_attach (struct target_ops *self, int pid)
{
ptrace_event_t pe;
specified by ARGS. If FROM_TTY is non-zero, be chatty about it. */
static void
-inf_ptrace_detach (struct target_ops *ops, char *args, int from_tty)
+inf_ptrace_detach (struct target_ops *ops, const char *args, int from_tty)
{
pid_t pid = ptid_get_pid (inferior_ptid);
int sig = 0;
- if (from_tty)
- {
- char *exec_file = get_exec_file (0);
- if (exec_file == 0)
- exec_file = "";
- printf_unfiltered (_("Detaching from program: %s, %s\n"), exec_file,
- target_pid_to_str (pid_to_ptid (pid)));
- gdb_flush (gdb_stdout);
- }
+ target_announce_detach (from_tty);
if (args)
sig = atoi (args);
error (_("This system does not support detaching from a process"));
#endif
+ inf_ptrace_detach_success (ops);
+}
+
+/* See inf-ptrace.h. */
+
+void
+inf_ptrace_detach_success (struct target_ops *ops)
+{
+ pid_t pid = ptid_get_pid (inferior_ptid);
+
inferior_ptid = null_ptid;
detach_inferior (pid);
- if (!have_inferiors ())
- unpush_target (ops);
+ inf_child_maybe_unpush_target (ops);
}
/* Kill the inferior. */
ptrace (PT_KILL, pid, (PTRACE_TYPE_ARG3)0, 0);
waitpid (pid, &status, 0);
- target_mourn_inferior ();
+ target_mourn_inferior (inferior_ptid);
}
-/* Stop the inferior. */
+/* Interrupt the inferior. */
static void
-inf_ptrace_stop (ptid_t ptid)
+inf_ptrace_interrupt (struct target_ops *self, ptid_t ptid)
{
/* Send a SIGINT to the process group. This acts just like the user
typed a ^C on the controlling terminal. Note that using a
kill (-inferior_process_group (), SIGINT);
}
+/* Return which PID to pass to ptrace in order to observe/control the
+ tracee identified by PTID. */
+
+pid_t
+get_ptrace_pid (ptid_t ptid)
+{
+ pid_t pid;
+
+ /* If we have an LWPID to work with, use it. Otherwise, we're
+ dealing with a non-threaded program/target. */
+ pid = ptid_get_lwp (ptid);
+ if (pid == 0)
+ pid = ptid_get_pid (ptid);
+ return pid;
+}
+
/* Resume execution of thread PTID, or all threads if PTID is -1. If
STEP is nonzero, single-step it. If SIGNAL is nonzero, give it
that signal. */
inf_ptrace_resume (struct target_ops *ops,
ptid_t ptid, int step, enum gdb_signal signal)
{
- pid_t pid = ptid_get_pid (ptid);
+ pid_t pid;
int request;
- if (pid == -1)
+ if (ptid_equal (minus_one_ptid, ptid))
/* Resume all threads. Traditionally ptrace() only supports
single-threaded processes, so simply resume the inferior. */
pid = ptid_get_pid (inferior_ptid);
+ else
+ pid = get_ptrace_pid (ptid);
if (catch_syscall_enabled () > 0)
request = PT_SYSCALL;
return pid_to_ptid (pid);
}
-/* Attempt a transfer all LEN bytes starting at OFFSET between the
- inferior's OBJECT:ANNEX space and GDB's READBUF/WRITEBUF buffer.
- Return the number of bytes actually transferred. */
+/* Transfer data via ptrace into process PID's memory from WRITEBUF, or
+ from process PID's memory into READBUF. Start at target address ADDR
+ and transfer up to LEN bytes. Exactly one of READBUF and WRITEBUF must
+ be non-null. Return the number of transferred bytes. */
+
+static ULONGEST
+inf_ptrace_peek_poke (pid_t pid, gdb_byte *readbuf,
+ const gdb_byte *writebuf,
+ ULONGEST addr, ULONGEST len)
+{
+ ULONGEST n;
+ unsigned int chunk;
+
+ /* We transfer aligned words. Thus align ADDR down to a word
+ boundary and determine how many bytes to skip at the
+ beginning. */
+ ULONGEST skip = addr & (sizeof (PTRACE_TYPE_RET) - 1);
+ addr -= skip;
+
+ for (n = 0;
+ n < len;
+ n += chunk, addr += sizeof (PTRACE_TYPE_RET), skip = 0)
+ {
+ /* Restrict to a chunk that fits in the current word. */
+ chunk = std::min (sizeof (PTRACE_TYPE_RET) - skip, len - n);
+
+ /* Use a union for type punning. */
+ union
+ {
+ PTRACE_TYPE_RET word;
+ gdb_byte byte[sizeof (PTRACE_TYPE_RET)];
+ } buf;
+
+ /* Read the word, also when doing a partial word write. */
+ if (readbuf != NULL || chunk < sizeof (PTRACE_TYPE_RET))
+ {
+ errno = 0;
+ buf.word = ptrace (PT_READ_I, pid,
+ (PTRACE_TYPE_ARG3)(uintptr_t) addr, 0);
+ if (errno != 0)
+ break;
+ if (readbuf != NULL)
+ memcpy (readbuf + n, buf.byte + skip, chunk);
+ }
+ if (writebuf != NULL)
+ {
+ memcpy (buf.byte + skip, writebuf + n, chunk);
+ errno = 0;
+ ptrace (PT_WRITE_D, pid, (PTRACE_TYPE_ARG3)(uintptr_t) addr,
+ buf.word);
+ if (errno != 0)
+ {
+ /* Using the appropriate one (I or D) is necessary for
+ Gould NP1, at least. */
+ errno = 0;
+ ptrace (PT_WRITE_I, pid, (PTRACE_TYPE_ARG3)(uintptr_t) addr,
+ buf.word);
+ if (errno != 0)
+ break;
+ }
+ }
+ }
+
+ return n;
+}
+
+/* Implement the to_xfer_partial target_ops method. */
-static LONGEST
+static enum target_xfer_status
inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
const char *annex, gdb_byte *readbuf,
const gdb_byte *writebuf,
- ULONGEST offset, LONGEST len)
+ ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
{
- pid_t pid = ptid_get_pid (inferior_ptid);
+ pid_t pid = get_ptrace_pid (inferior_ptid);
switch (object)
{
errno = 0;
if (ptrace (PT_IO, pid, (caddr_t)&piod, 0) == 0)
- /* Return the actual number of bytes read or written. */
- return piod.piod_len;
+ {
+ /* Return the actual number of bytes read or written. */
+ *xfered_len = piod.piod_len;
+ return (piod.piod_len == 0) ? TARGET_XFER_EOF : TARGET_XFER_OK;
+ }
/* If the PT_IO request is somehow not supported, fallback on
using PT_WRITE_D/PT_READ_D. Otherwise we will return zero
to indicate failure. */
if (errno != EINVAL)
- return 0;
+ return TARGET_XFER_EOF;
}
#endif
- {
- union
- {
- PTRACE_TYPE_RET word;
- gdb_byte byte[sizeof (PTRACE_TYPE_RET)];
- } buffer;
- ULONGEST rounded_offset;
- LONGEST partial_len;
-
- /* Round the start offset down to the next long word
- boundary. */
- rounded_offset = offset & -(ULONGEST) sizeof (PTRACE_TYPE_RET);
-
- /* Since ptrace will transfer a single word starting at that
- rounded_offset the partial_len needs to be adjusted down to
- that (remember this function only does a single transfer).
- Should the required length be even less, adjust it down
- again. */
- partial_len = (rounded_offset + sizeof (PTRACE_TYPE_RET)) - offset;
- if (partial_len > len)
- partial_len = len;
-
- if (writebuf)
- {
- /* If OFFSET:PARTIAL_LEN is smaller than
- ROUNDED_OFFSET:WORDSIZE then a read/modify write will
- be needed. Read in the entire word. */
- if (rounded_offset < offset
- || (offset + partial_len
- < rounded_offset + sizeof (PTRACE_TYPE_RET)))
- /* Need part of initial word -- fetch it. */
- buffer.word = ptrace (PT_READ_I, pid,
- (PTRACE_TYPE_ARG3)(uintptr_t)
- rounded_offset, 0);
-
- /* Copy data to be written over corresponding part of
- buffer. */
- memcpy (buffer.byte + (offset - rounded_offset),
- writebuf, partial_len);
-
- errno = 0;
- ptrace (PT_WRITE_D, pid,
- (PTRACE_TYPE_ARG3)(uintptr_t)rounded_offset,
- buffer.word);
- if (errno)
- {
- /* Using the appropriate one (I or D) is necessary for
- Gould NP1, at least. */
- errno = 0;
- ptrace (PT_WRITE_I, pid,
- (PTRACE_TYPE_ARG3)(uintptr_t)rounded_offset,
- buffer.word);
- if (errno)
- return 0;
- }
- }
-
- if (readbuf)
- {
- errno = 0;
- buffer.word = ptrace (PT_READ_I, pid,
- (PTRACE_TYPE_ARG3)(uintptr_t)rounded_offset,
- 0);
- if (errno)
- return 0;
- /* Copy appropriate bytes out of the buffer. */
- memcpy (readbuf, buffer.byte + (offset - rounded_offset),
- partial_len);
- }
-
- return partial_len;
- }
+ *xfered_len = inf_ptrace_peek_poke (pid, readbuf, writebuf,
+ offset, len);
+ return *xfered_len != 0 ? TARGET_XFER_OK : TARGET_XFER_EOF;
case TARGET_OBJECT_UNWIND_TABLE:
- return -1;
+ return TARGET_XFER_E_IO;
case TARGET_OBJECT_AUXV:
#if defined (PT_IO) && defined (PIOD_READ_AUXV)
struct ptrace_io_desc piod;
if (writebuf)
- return -1;
+ return TARGET_XFER_E_IO;
piod.piod_op = PIOD_READ_AUXV;
piod.piod_addr = readbuf;
piod.piod_offs = (void *) (long) offset;
errno = 0;
if (ptrace (PT_IO, pid, (caddr_t)&piod, 0) == 0)
- /* Return the actual number of bytes read or written. */
- return piod.piod_len;
+ {
+ /* Return the actual number of bytes read or written. */
+ *xfered_len = piod.piod_len;
+ return (piod.piod_len == 0) ? TARGET_XFER_EOF : TARGET_XFER_OK;
+ }
}
#endif
- return -1;
+ return TARGET_XFER_E_IO;
case TARGET_OBJECT_WCOOKIE:
- return -1;
+ return TARGET_XFER_E_IO;
default:
- return -1;
+ return TARGET_XFER_E_IO;
}
}
target_pid_to_str (inferior_ptid));
}
-static char *
+static const char *
inf_ptrace_pid_to_str (struct target_ops *ops, ptid_t ptid)
{
return normal_pid_to_str (ptid);
t->to_create_inferior = inf_ptrace_create_inferior;
#ifdef PT_GET_PROCESS_STATE
t->to_follow_fork = inf_ptrace_follow_fork;
+ t->to_insert_fork_catchpoint = inf_ptrace_insert_fork_catchpoint;
+ t->to_remove_fork_catchpoint = inf_ptrace_remove_fork_catchpoint;
t->to_post_startup_inferior = inf_ptrace_post_startup_inferior;
t->to_post_attach = inf_ptrace_post_attach;
#endif
t->to_mourn_inferior = inf_ptrace_mourn_inferior;
t->to_thread_alive = inf_ptrace_thread_alive;
t->to_pid_to_str = inf_ptrace_pid_to_str;
- t->to_stop = inf_ptrace_stop;
+ t->to_interrupt = inf_ptrace_interrupt;
t->to_xfer_partial = inf_ptrace_xfer_partial;
#if defined (PT_IO) && defined (PIOD_READ_AUXV)
t->to_auxv_parse = inf_ptrace_auxv_parse;
static void
inf_ptrace_fetch_register (struct regcache *regcache, int regnum)
{
- struct gdbarch *gdbarch = get_regcache_arch (regcache);
+ struct gdbarch *gdbarch = regcache->arch ();
CORE_ADDR addr;
size_t size;
PTRACE_TYPE_RET *buf;
- int pid, i;
+ 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);
return;
}
- /* Cater for systems like GNU/Linux, that implement threads as
- separate processes. */
- pid = ptid_get_lwp (inferior_ptid);
- if (pid == 0)
- pid = ptid_get_pid (inferior_ptid);
+ pid = get_ptrace_pid (regcache_get_ptid (regcache));
size = register_size (gdbarch, regnum);
gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0);
- buf = alloca (size);
+ 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++)
{
if (regnum == -1)
for (regnum = 0;
- regnum < gdbarch_num_regs (get_regcache_arch (regcache));
+ regnum < gdbarch_num_regs (regcache->arch ());
regnum++)
inf_ptrace_fetch_register (regcache, regnum);
else
static void
inf_ptrace_store_register (const struct regcache *regcache, int regnum)
{
- struct gdbarch *gdbarch = get_regcache_arch (regcache);
+ struct gdbarch *gdbarch = regcache->arch ();
CORE_ADDR addr;
size_t size;
PTRACE_TYPE_RET *buf;
- int pid, i;
+ 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);
|| gdbarch_cannot_store_register (gdbarch, regnum))
return;
- /* Cater for systems like GNU/Linux, that implement threads as
- separate processes. */
- pid = ptid_get_lwp (inferior_ptid);
- if (pid == 0)
- pid = ptid_get_pid (inferior_ptid);
+ pid = get_ptrace_pid (regcache_get_ptid (regcache));
size = register_size (gdbarch, regnum);
gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0);
- buf = alloca (size);
+ buf = (PTRACE_TYPE_RET *) alloca (size);
/* Write the register contents into the inferior a chunk at a time. */
regcache_raw_collect (regcache, regnum, buf);
{
if (regnum == -1)
for (regnum = 0;
- regnum < gdbarch_num_regs (get_regcache_arch (regcache));
+ regnum < gdbarch_num_regs (regcache->arch ());
regnum++)
inf_ptrace_store_register (regcache, regnum);
else
projects / deliverable / binutils-gdb.git / blobdiff