blob: e3e30afd7a5450b65101ac2c90d8be7190bd65dd [file] [log] [blame]
/* Select target systems and architectures at runtime for GDB.
Copyright (C) 1990-2020 Free Software Foundation, Inc.
Contributed by Cygnus Support.
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 "target.h"
#include "target-dcache.h"
#include "gdbcmd.h"
#include "symtab.h"
#include "inferior.h"
#include "infrun.h"
#include "bfd.h"
#include "symfile.h"
#include "objfiles.h"
#include "dcache.h"
#include <signal.h>
#include "regcache.h"
#include "gdbcore.h"
#include "target-descriptions.h"
#include "gdbthread.h"
#include "solib.h"
#include "exec.h"
#include "inline-frame.h"
#include "tracepoint.h"
#include "gdb/fileio.h"
#include "gdbsupport/agent.h"
#include "auxv.h"
#include "target-debug.h"
#include "top.h"
#include "event-top.h"
#include <algorithm>
#include "gdbsupport/byte-vector.h"
#include "terminal.h"
#include <unordered_map>
static void generic_tls_error (void) ATTRIBUTE_NORETURN;
static void default_terminal_info (struct target_ops *, const char *, int);
static int default_watchpoint_addr_within_range (struct target_ops *,
CORE_ADDR, CORE_ADDR, int);
static int default_region_ok_for_hw_watchpoint (struct target_ops *,
CORE_ADDR, int);
static void default_rcmd (struct target_ops *, const char *, struct ui_file *);
static ptid_t default_get_ada_task_ptid (struct target_ops *self,
long lwp, long tid);
static int default_follow_fork (struct target_ops *self, int follow_child,
int detach_fork);
static void default_mourn_inferior (struct target_ops *self);
static int default_search_memory (struct target_ops *ops,
CORE_ADDR start_addr,
ULONGEST search_space_len,
const gdb_byte *pattern,
ULONGEST pattern_len,
CORE_ADDR *found_addrp);
static int default_verify_memory (struct target_ops *self,
const gdb_byte *data,
CORE_ADDR memaddr, ULONGEST size);
static void tcomplain (void) ATTRIBUTE_NORETURN;
static struct target_ops *find_default_run_target (const char *);
static int dummy_find_memory_regions (struct target_ops *self,
find_memory_region_ftype ignore1,
void *ignore2);
static char *dummy_make_corefile_notes (struct target_ops *self,
bfd *ignore1, int *ignore2);
static std::string default_pid_to_str (struct target_ops *ops, ptid_t ptid);
static enum exec_direction_kind default_execution_direction
(struct target_ops *self);
/* Mapping between target_info objects (which have address identity)
and corresponding open/factory function/callback. Each add_target
call adds one entry to this map, and registers a "target
TARGET_NAME" command that when invoked calls the factory registered
here. The target_info object is associated with the command via
the command's context. */
static std::unordered_map<const target_info *, target_open_ftype *>
target_factories;
/* The singleton debug target. */
static struct target_ops *the_debug_target;
/* The target stack. */
static target_stack g_target_stack;
/* Top of target stack. */
/* The target structure we are currently using to talk to a process
or file or whatever "inferior" we have. */
target_ops *
current_top_target ()
{
return g_target_stack.top ();
}
/* Command list for target. */
static struct cmd_list_element *targetlist = NULL;
/* True if we should trust readonly sections from the
executable when reading memory. */
static bool trust_readonly = false;
/* Nonzero if we should show true memory content including
memory breakpoint inserted by gdb. */
static int show_memory_breakpoints = 0;
/* These globals control whether GDB attempts to perform these
operations; they are useful for targets that need to prevent
inadvertent disruption, such as in non-stop mode. */
bool may_write_registers = true;
bool may_write_memory = true;
bool may_insert_breakpoints = true;
bool may_insert_tracepoints = true;
bool may_insert_fast_tracepoints = true;
bool may_stop = true;
/* Non-zero if we want to see trace of target level stuff. */
static unsigned int targetdebug = 0;
static void
set_targetdebug (const char *args, int from_tty, struct cmd_list_element *c)
{
if (targetdebug)
push_target (the_debug_target);
else
unpush_target (the_debug_target);
}
static void
show_targetdebug (struct ui_file *file, int from_tty,
struct cmd_list_element *c, const char *value)
{
fprintf_filtered (file, _("Target debugging is %s.\n"), value);
}
/* The user just typed 'target' without the name of a target. */
static void
target_command (const char *arg, int from_tty)
{
fputs_filtered ("Argument required (target name). Try `help target'\n",
gdb_stdout);
}
int
target_has_all_memory_1 (void)
{
for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
if (t->has_all_memory ())
return 1;
return 0;
}
int
target_has_memory_1 (void)
{
for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
if (t->has_memory ())
return 1;
return 0;
}
int
target_has_stack_1 (void)
{
for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
if (t->has_stack ())
return 1;
return 0;
}
int
target_has_registers_1 (void)
{
for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
if (t->has_registers ())
return 1;
return 0;
}
int
target_has_execution_1 (ptid_t the_ptid)
{
for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
if (t->has_execution (the_ptid))
return 1;
return 0;
}
int
target_has_execution_current (void)
{
return target_has_execution_1 (inferior_ptid);
}
/* This is used to implement the various target commands. */
static void
open_target (const char *args, int from_tty, struct cmd_list_element *command)
{
auto *ti = static_cast<target_info *> (get_cmd_context (command));
target_open_ftype *func = target_factories[ti];
if (targetdebug)
fprintf_unfiltered (gdb_stdlog, "-> %s->open (...)\n",
ti->shortname);
func (args, from_tty);
if (targetdebug)
fprintf_unfiltered (gdb_stdlog, "<- %s->open (%s, %d)\n",
ti->shortname, args, from_tty);
}
/* See target.h. */
void
add_target (const target_info &t, target_open_ftype *func,
completer_ftype *completer)
{
struct cmd_list_element *c;
auto &func_slot = target_factories[&t];
if (func_slot != nullptr)
internal_error (__FILE__, __LINE__,
_("target already added (\"%s\")."), t.shortname);
func_slot = func;
if (targetlist == NULL)
add_prefix_cmd ("target", class_run, target_command, _("\
Connect to a target machine or process.\n\
The first argument is the type or protocol of the target machine.\n\
Remaining arguments are interpreted by the target protocol. For more\n\
information on the arguments for a particular protocol, type\n\
`help target ' followed by the protocol name."),
&targetlist, "target ", 0, &cmdlist);
c = add_cmd (t.shortname, no_class, t.doc, &targetlist);
set_cmd_context (c, (void *) &t);
set_cmd_sfunc (c, open_target);
if (completer != NULL)
set_cmd_completer (c, completer);
}
/* See target.h. */
void
add_deprecated_target_alias (const target_info &tinfo, const char *alias)
{
struct cmd_list_element *c;
char *alt;
/* If we use add_alias_cmd, here, we do not get the deprecated warning,
see PR cli/15104. */
c = add_cmd (alias, no_class, tinfo.doc, &targetlist);
set_cmd_sfunc (c, open_target);
set_cmd_context (c, (void *) &tinfo);
alt = xstrprintf ("target %s", tinfo.shortname);
deprecate_cmd (c, alt);
}
/* Stub functions */
void
target_kill (void)
{
current_top_target ()->kill ();
}
void
target_load (const char *arg, int from_tty)
{
target_dcache_invalidate ();
current_top_target ()->load (arg, from_tty);
}
/* Define it. */
target_terminal_state target_terminal::m_terminal_state
= target_terminal_state::is_ours;
/* See target/target.h. */
void
target_terminal::init (void)
{
current_top_target ()->terminal_init ();
m_terminal_state = target_terminal_state::is_ours;
}
/* See target/target.h. */
void
target_terminal::inferior (void)
{
struct ui *ui = current_ui;
/* A background resume (``run&'') should leave GDB in control of the
terminal. */
if (ui->prompt_state != PROMPT_BLOCKED)
return;
/* Since we always run the inferior in the main console (unless "set
inferior-tty" is in effect), when some UI other than the main one
calls target_terminal::inferior, then we leave the main UI's
terminal settings as is. */
if (ui != main_ui)
return;
/* If GDB is resuming the inferior in the foreground, install
inferior's terminal modes. */
struct inferior *inf = current_inferior ();
if (inf->terminal_state != target_terminal_state::is_inferior)
{
current_top_target ()->terminal_inferior ();
inf->terminal_state = target_terminal_state::is_inferior;
}
m_terminal_state = target_terminal_state::is_inferior;
/* If the user hit C-c before, pretend that it was hit right
here. */
if (check_quit_flag ())
target_pass_ctrlc ();
}
/* See target/target.h. */
void
target_terminal::restore_inferior (void)
{
struct ui *ui = current_ui;
/* See target_terminal::inferior(). */
if (ui->prompt_state != PROMPT_BLOCKED || ui != main_ui)
return;
/* Restore the terminal settings of inferiors that were in the
foreground but are now ours_for_output due to a temporary
target_target::ours_for_output() call. */
{
scoped_restore_current_inferior restore_inferior;
for (::inferior *inf : all_inferiors ())
{
if (inf->terminal_state == target_terminal_state::is_ours_for_output)
{
set_current_inferior (inf);
current_top_target ()->terminal_inferior ();
inf->terminal_state = target_terminal_state::is_inferior;
}
}
}
m_terminal_state = target_terminal_state::is_inferior;
/* If the user hit C-c before, pretend that it was hit right
here. */
if (check_quit_flag ())
target_pass_ctrlc ();
}
/* Switch terminal state to DESIRED_STATE, either is_ours, or
is_ours_for_output. */
static void
target_terminal_is_ours_kind (target_terminal_state desired_state)
{
scoped_restore_current_inferior restore_inferior;
/* Must do this in two passes. First, have all inferiors save the
current terminal settings. Then, after all inferiors have add a
chance to safely save the terminal settings, restore GDB's
terminal settings. */
for (inferior *inf : all_inferiors ())
{
if (inf->terminal_state == target_terminal_state::is_inferior)
{
set_current_inferior (inf);
current_top_target ()->terminal_save_inferior ();
}
}
for (inferior *inf : all_inferiors ())
{
/* Note we don't check is_inferior here like above because we
need to handle 'is_ours_for_output -> is_ours' too. Careful
to never transition from 'is_ours' to 'is_ours_for_output',
though. */
if (inf->terminal_state != target_terminal_state::is_ours
&& inf->terminal_state != desired_state)
{
set_current_inferior (inf);
if (desired_state == target_terminal_state::is_ours)
current_top_target ()->terminal_ours ();
else if (desired_state == target_terminal_state::is_ours_for_output)
current_top_target ()->terminal_ours_for_output ();
else
gdb_assert_not_reached ("unhandled desired state");
inf->terminal_state = desired_state;
}
}
}
/* See target/target.h. */
void
target_terminal::ours ()
{
struct ui *ui = current_ui;
/* See target_terminal::inferior. */
if (ui != main_ui)
return;
if (m_terminal_state == target_terminal_state::is_ours)
return;
target_terminal_is_ours_kind (target_terminal_state::is_ours);
m_terminal_state = target_terminal_state::is_ours;
}
/* See target/target.h. */
void
target_terminal::ours_for_output ()
{
struct ui *ui = current_ui;
/* See target_terminal::inferior. */
if (ui != main_ui)
return;
if (!target_terminal::is_inferior ())
return;
target_terminal_is_ours_kind (target_terminal_state::is_ours_for_output);
target_terminal::m_terminal_state = target_terminal_state::is_ours_for_output;
}
/* See target/target.h. */
void
target_terminal::info (const char *arg, int from_tty)
{
current_top_target ()->terminal_info (arg, from_tty);
}
/* See target.h. */
bool
target_supports_terminal_ours (void)
{
/* This can be called before there is any target, so we must check
for nullptr here. */
target_ops *top = current_top_target ();
if (top == nullptr)
return false;
return top->supports_terminal_ours ();
}
static void
tcomplain (void)
{
error (_("You can't do that when your target is `%s'"),
current_top_target ()->shortname ());
}
void
noprocess (void)
{
error (_("You can't do that without a process to debug."));
}
static void
default_terminal_info (struct target_ops *self, const char *args, int from_tty)
{
printf_unfiltered (_("No saved terminal information.\n"));
}
/* A default implementation for the to_get_ada_task_ptid target method.
This function builds the PTID by using both LWP and TID as part of
the PTID lwp and tid elements. The pid used is the pid of the
inferior_ptid. */
static ptid_t
default_get_ada_task_ptid (struct target_ops *self, long lwp, long tid)
{
return ptid_t (inferior_ptid.pid (), lwp, tid);
}
static enum exec_direction_kind
default_execution_direction (struct target_ops *self)
{
if (!target_can_execute_reverse)
return EXEC_FORWARD;
else if (!target_can_async_p ())
return EXEC_FORWARD;
else
gdb_assert_not_reached ("\
to_execution_direction must be implemented for reverse async");
}
/* See target.h. */
void
target_stack::push (target_ops *t)
{
/* If there's already a target at this stratum, remove it. */
strata stratum = t->stratum ();
if (m_stack[stratum] != NULL)
unpush (m_stack[stratum]);
/* Now add the new one. */
m_stack[stratum] = t;
if (m_top < stratum)
m_top = stratum;
}
/* See target.h. */
void
push_target (struct target_ops *t)
{
g_target_stack.push (t);
}
/* See target.h */
void
push_target (target_ops_up &&t)
{
g_target_stack.push (t.get ());
t.release ();
}
/* See target.h. */
int
unpush_target (struct target_ops *t)
{
return g_target_stack.unpush (t);
}
/* See target.h. */
bool
target_stack::unpush (target_ops *t)
{
gdb_assert (t != NULL);
strata stratum = t->stratum ();
if (stratum == dummy_stratum)
internal_error (__FILE__, __LINE__,
_("Attempt to unpush the dummy target"));
/* Look for the specified target. Note that a target can only occur
once in the target stack. */
if (m_stack[stratum] != t)
{
/* If T wasn't pushed, quit. Only open targets should be
closed. */
return false;
}
/* Unchain the target. */
m_stack[stratum] = NULL;
if (m_top == stratum)
m_top = t->beneath ()->stratum ();
/* Finally close the target. Note we do this after unchaining, so
any target method calls from within the target_close
implementation don't end up in T anymore. */
target_close (t);
return true;
}
/* Unpush TARGET and assert that it worked. */
static void
unpush_target_and_assert (struct target_ops *target)
{
if (!unpush_target (target))
{
fprintf_unfiltered (gdb_stderr,
"pop_all_targets couldn't find target %s\n",
target->shortname ());
internal_error (__FILE__, __LINE__,
_("failed internal consistency check"));
}
}
void
pop_all_targets_above (enum strata above_stratum)
{
while ((int) (current_top_target ()->stratum ()) > (int) above_stratum)
unpush_target_and_assert (current_top_target ());
}
/* See target.h. */
void
pop_all_targets_at_and_above (enum strata stratum)
{
while ((int) (current_top_target ()->stratum ()) >= (int) stratum)
unpush_target_and_assert (current_top_target ());
}
void
pop_all_targets (void)
{
pop_all_targets_above (dummy_stratum);
}
/* Return 1 if T is now pushed in the target stack. Return 0 otherwise. */
int
target_is_pushed (struct target_ops *t)
{
return g_target_stack.is_pushed (t);
}
/* Default implementation of to_get_thread_local_address. */
static void
generic_tls_error (void)
{
throw_error (TLS_GENERIC_ERROR,
_("Cannot find thread-local variables on this target"));
}
/* Using the objfile specified in OBJFILE, find the address for the
current thread's thread-local storage with offset OFFSET. */
CORE_ADDR
target_translate_tls_address (struct objfile *objfile, CORE_ADDR offset)
{
volatile CORE_ADDR addr = 0;
struct target_ops *target = current_top_target ();
struct gdbarch *gdbarch = target_gdbarch ();
if (gdbarch_fetch_tls_load_module_address_p (gdbarch))
{
ptid_t ptid = inferior_ptid;
try
{
CORE_ADDR lm_addr;
/* Fetch the load module address for this objfile. */
lm_addr = gdbarch_fetch_tls_load_module_address (gdbarch,
objfile);
if (gdbarch_get_thread_local_address_p (gdbarch))
addr = gdbarch_get_thread_local_address (gdbarch, ptid, lm_addr,
offset);
else
addr = target->get_thread_local_address (ptid, lm_addr, offset);
}
/* If an error occurred, print TLS related messages here. Otherwise,
throw the error to some higher catcher. */
catch (const gdb_exception &ex)
{
int objfile_is_library = (objfile->flags & OBJF_SHARED);
switch (ex.error)
{
case TLS_NO_LIBRARY_SUPPORT_ERROR:
error (_("Cannot find thread-local variables "
"in this thread library."));
break;
case TLS_LOAD_MODULE_NOT_FOUND_ERROR:
if (objfile_is_library)
error (_("Cannot find shared library `%s' in dynamic"
" linker's load module list"), objfile_name (objfile));
else
error (_("Cannot find executable file `%s' in dynamic"
" linker's load module list"), objfile_name (objfile));
break;
case TLS_NOT_ALLOCATED_YET_ERROR:
if (objfile_is_library)
error (_("The inferior has not yet allocated storage for"
" thread-local variables in\n"
"the shared library `%s'\n"
"for %s"),
objfile_name (objfile),
target_pid_to_str (ptid).c_str ());
else
error (_("The inferior has not yet allocated storage for"
" thread-local variables in\n"
"the executable `%s'\n"
"for %s"),
objfile_name (objfile),
target_pid_to_str (ptid).c_str ());
break;
case TLS_GENERIC_ERROR:
if (objfile_is_library)
error (_("Cannot find thread-local storage for %s, "
"shared library %s:\n%s"),
target_pid_to_str (ptid).c_str (),
objfile_name (objfile), ex.what ());
else
error (_("Cannot find thread-local storage for %s, "
"executable file %s:\n%s"),
target_pid_to_str (ptid).c_str (),
objfile_name (objfile), ex.what ());
break;
default:
throw;
break;
}
}
}
else
error (_("Cannot find thread-local variables on this target"));
return addr;
}
const char *
target_xfer_status_to_string (enum target_xfer_status status)
{
#define CASE(X) case X: return #X
switch (status)
{
CASE(TARGET_XFER_E_IO);
CASE(TARGET_XFER_UNAVAILABLE);
default:
return "<unknown>";
}
#undef CASE
};
#undef MIN
#define MIN(A, B) (((A) <= (B)) ? (A) : (B))
/* target_read_string -- read a null terminated string, up to LEN bytes,
from MEMADDR in target. Set *ERRNOP to the errno code, or 0 if successful.
Set *STRING to a pointer to malloc'd memory containing the data; the caller
is responsible for freeing it. Return the number of bytes successfully
read. */
int
target_read_string (CORE_ADDR memaddr, gdb::unique_xmalloc_ptr<char> *string,
int len, int *errnop)
{
int tlen, offset, i;
gdb_byte buf[4];
int errcode = 0;
char *buffer;
int buffer_allocated;
char *bufptr;
unsigned int nbytes_read = 0;
gdb_assert (string);
/* Small for testing. */
buffer_allocated = 4;
buffer = (char *) xmalloc (buffer_allocated);
bufptr = buffer;
while (len > 0)
{
tlen = MIN (len, 4 - (memaddr & 3));
offset = memaddr & 3;
errcode = target_read_memory (memaddr & ~3, buf, sizeof buf);
if (errcode != 0)
{
/* The transfer request might have crossed the boundary to an
unallocated region of memory. Retry the transfer, requesting
a single byte. */
tlen = 1;
offset = 0;
errcode = target_read_memory (memaddr, buf, 1);
if (errcode != 0)
goto done;
}
if (bufptr - buffer + tlen > buffer_allocated)
{
unsigned int bytes;
bytes = bufptr - buffer;
buffer_allocated *= 2;
buffer = (char *) xrealloc (buffer, buffer_allocated);
bufptr = buffer + bytes;
}
for (i = 0; i < tlen; i++)
{
*bufptr++ = buf[i + offset];
if (buf[i + offset] == '\000')
{
nbytes_read += i + 1;
goto done;
}
}
memaddr += tlen;
len -= tlen;
nbytes_read += tlen;
}
done:
string->reset (buffer);
if (errnop != NULL)
*errnop = errcode;
return nbytes_read;
}
struct target_section_table *
target_get_section_table (struct target_ops *target)
{
return target->get_section_table ();
}
/* Find a section containing ADDR. */
struct target_section *
target_section_by_addr (struct target_ops *target, CORE_ADDR addr)
{
struct target_section_table *table = target_get_section_table (target);
struct target_section *secp;
if (table == NULL)
return NULL;
for (secp = table->sections; secp < table->sections_end; secp++)
{
if (addr >= secp->addr && addr < secp->endaddr)
return secp;
}
return NULL;
}
/* Helper for the memory xfer routines. Checks the attributes of the
memory region of MEMADDR against the read or write being attempted.
If the access is permitted returns true, otherwise returns false.
REGION_P is an optional output parameter. If not-NULL, it is
filled with a pointer to the memory region of MEMADDR. REG_LEN
returns LEN trimmed to the end of the region. This is how much the
caller can continue requesting, if the access is permitted. A
single xfer request must not straddle memory region boundaries. */
static int
memory_xfer_check_region (gdb_byte *readbuf, const gdb_byte *writebuf,
ULONGEST memaddr, ULONGEST len, ULONGEST *reg_len,
struct mem_region **region_p)
{
struct mem_region *region;
region = lookup_mem_region (memaddr);
if (region_p != NULL)
*region_p = region;
switch (region->attrib.mode)
{
case MEM_RO:
if (writebuf != NULL)
return 0;
break;
case MEM_WO:
if (readbuf != NULL)
return 0;
break;
case MEM_FLASH:
/* We only support writing to flash during "load" for now. */
if (writebuf != NULL)
error (_("Writing to flash memory forbidden in this context"));
break;
case MEM_NONE:
return 0;
}
/* region->hi == 0 means there's no upper bound. */
if (memaddr + len < region->hi || region->hi == 0)
*reg_len = len;
else
*reg_len = region->hi - memaddr;
return 1;
}
/* Read memory from more than one valid target. A core file, for
instance, could have some of memory but delegate other bits to
the target below it. So, we must manually try all targets. */
enum target_xfer_status
raw_memory_xfer_partial (struct target_ops *ops, gdb_byte *readbuf,
const gdb_byte *writebuf, ULONGEST memaddr, LONGEST len,
ULONGEST *xfered_len)
{
enum target_xfer_status res;
do
{
res = ops->xfer_partial (TARGET_OBJECT_MEMORY, NULL,
readbuf, writebuf, memaddr, len,
xfered_len);
if (res == TARGET_XFER_OK)
break;
/* Stop if the target reports that the memory is not available. */
if (res == TARGET_XFER_UNAVAILABLE)
break;
/* We want to continue past core files to executables, but not
past a running target's memory. */
if (ops->has_all_memory ())
break;
ops = ops->beneath ();
}
while (ops != NULL);
/* The cache works at the raw memory level. Make sure the cache
gets updated with raw contents no matter what kind of memory
object was originally being written. Note we do write-through
first, so that if it fails, we don't write to the cache contents
that never made it to the target. */
if (writebuf != NULL
&& inferior_ptid != null_ptid
&& target_dcache_init_p ()
&& (stack_cache_enabled_p () || code_cache_enabled_p ()))
{
DCACHE *dcache = target_dcache_get ();
/* Note that writing to an area of memory which wasn't present
in the cache doesn't cause it to be loaded in. */
dcache_update (dcache, res, memaddr, writebuf, *xfered_len);
}
return res;
}
/* Perform a partial memory transfer.
For docs see target.h, to_xfer_partial. */
static enum target_xfer_status
memory_xfer_partial_1 (struct target_ops *ops, enum target_object object,
gdb_byte *readbuf, const gdb_byte *writebuf, ULONGEST memaddr,
ULONGEST len, ULONGEST *xfered_len)
{
enum target_xfer_status res;
ULONGEST reg_len;
struct mem_region *region;
struct inferior *inf;
/* For accesses to unmapped overlay sections, read directly from
files. Must do this first, as MEMADDR may need adjustment. */
if (readbuf != NULL && overlay_debugging)
{
struct obj_section *section = find_pc_overlay (memaddr);
if (pc_in_unmapped_range (memaddr, section))
{
struct target_section_table *table
= target_get_section_table (ops);
const char *section_name = section->the_bfd_section->name;
memaddr = overlay_mapped_address (memaddr, section);
return section_table_xfer_memory_partial (readbuf, writebuf,
memaddr, len, xfered_len,
table->sections,
table->sections_end,
section_name);
}
}
/* Try the executable files, if "trust-readonly-sections" is set. */
if (readbuf != NULL && trust_readonly)
{
struct target_section *secp;
struct target_section_table *table;
secp = target_section_by_addr (ops, memaddr);
if (secp != NULL
&& (bfd_section_flags (secp->the_bfd_section) & SEC_READONLY))
{
table = target_get_section_table (ops);
return section_table_xfer_memory_partial (readbuf, writebuf,
memaddr, len, xfered_len,
table->sections,
table->sections_end,
NULL);
}
}
/* Try GDB's internal data cache. */
if (!memory_xfer_check_region (readbuf, writebuf, memaddr, len, &reg_len,
&region))
return TARGET_XFER_E_IO;
if (inferior_ptid != null_ptid)
inf = current_inferior ();
else
inf = NULL;
if (inf != NULL
&& readbuf != NULL
/* The dcache reads whole cache lines; that doesn't play well
with reading from a trace buffer, because reading outside of
the collected memory range fails. */
&& get_traceframe_number () == -1
&& (region->attrib.cache
|| (stack_cache_enabled_p () && object == TARGET_OBJECT_STACK_MEMORY)
|| (code_cache_enabled_p () && object == TARGET_OBJECT_CODE_MEMORY)))
{
DCACHE *dcache = target_dcache_get_or_init ();
return dcache_read_memory_partial (ops, dcache, memaddr, readbuf,
reg_len, xfered_len);
}
/* If none of those methods found the memory we wanted, fall back
to a target partial transfer. Normally a single call to
to_xfer_partial is enough; if it doesn't recognize an object
it will call the to_xfer_partial of the next target down.
But for memory this won't do. Memory is the only target
object which can be read from more than one valid target.
A core file, for instance, could have some of memory but
delegate other bits to the target below it. So, we must
manually try all targets. */
res = raw_memory_xfer_partial (ops, readbuf, writebuf, memaddr, reg_len,
xfered_len);
/* If we still haven't got anything, return the last error. We
give up. */
return res;
}
/* Perform a partial memory transfer. For docs see target.h,
to_xfer_partial. */
static enum target_xfer_status
memory_xfer_partial (struct target_ops *ops, enum target_object object,
gdb_byte *readbuf, const gdb_byte *writebuf,
ULONGEST memaddr, ULONGEST len, ULONGEST *xfered_len)
{
enum target_xfer_status res;
/* Zero length requests are ok and require no work. */
if (len == 0)
return TARGET_XFER_EOF;
memaddr = address_significant (target_gdbarch (), memaddr);
/* Fill in READBUF with breakpoint shadows, or WRITEBUF with
breakpoint insns, thus hiding out from higher layers whether
there are software breakpoints inserted in the code stream. */
if (readbuf != NULL)
{
res = memory_xfer_partial_1 (ops, object, readbuf, NULL, memaddr, len,
xfered_len);
if (res == TARGET_XFER_OK && !show_memory_breakpoints)
breakpoint_xfer_memory (readbuf, NULL, NULL, memaddr, *xfered_len);
}
else
{
/* A large write request is likely to be partially satisfied
by memory_xfer_partial_1. We will continually malloc
and free a copy of the entire write request for breakpoint
shadow handling even though we only end up writing a small
subset of it. Cap writes to a limit specified by the target
to mitigate this. */
len = std::min (ops->get_memory_xfer_limit (), len);
gdb::byte_vector buf (writebuf, writebuf + len);
breakpoint_xfer_memory (NULL, buf.data (), writebuf, memaddr, len);
res = memory_xfer_partial_1 (ops, object, NULL, buf.data (), memaddr, len,
xfered_len);
}
return res;
}
scoped_restore_tmpl<int>
make_scoped_restore_show_memory_breakpoints (int show)
{
return make_scoped_restore (&show_memory_breakpoints, show);
}
/* For docs see target.h, to_xfer_partial. */
enum target_xfer_status
target_xfer_partial (struct target_ops *ops,
enum target_object object, const char *annex,
gdb_byte *readbuf, const gdb_byte *writebuf,
ULONGEST offset, ULONGEST len,
ULONGEST *xfered_len)
{
enum target_xfer_status retval;
/* Transfer is done when LEN is zero. */
if (len == 0)
return TARGET_XFER_EOF;
if (writebuf && !may_write_memory)
error (_("Writing to memory is not allowed (addr %s, len %s)"),
core_addr_to_string_nz (offset), plongest (len));
*xfered_len = 0;
/* If this is a memory transfer, let the memory-specific code
have a look at it instead. Memory transfers are more
complicated. */
if (object == TARGET_OBJECT_MEMORY || object == TARGET_OBJECT_STACK_MEMORY
|| object == TARGET_OBJECT_CODE_MEMORY)
retval = memory_xfer_partial (ops, object, readbuf,
writebuf, offset, len, xfered_len);
else if (object == TARGET_OBJECT_RAW_MEMORY)
{
/* Skip/avoid accessing the target if the memory region
attributes block the access. Check this here instead of in
raw_memory_xfer_partial as otherwise we'd end up checking
this twice in the case of the memory_xfer_partial path is
taken; once before checking the dcache, and another in the
tail call to raw_memory_xfer_partial. */
if (!memory_xfer_check_region (readbuf, writebuf, offset, len, &len,
NULL))
return TARGET_XFER_E_IO;
/* Request the normal memory object from other layers. */
retval = raw_memory_xfer_partial (ops, readbuf, writebuf, offset, len,
xfered_len);
}
else
retval = ops->xfer_partial (object, annex, readbuf,
writebuf, offset, len, xfered_len);
if (targetdebug)
{
const unsigned char *myaddr = NULL;
fprintf_unfiltered (gdb_stdlog,
"%s:target_xfer_partial "
"(%d, %s, %s, %s, %s, %s) = %d, %s",
ops->shortname (),
(int) object,
(annex ? annex : "(null)"),
host_address_to_string (readbuf),
host_address_to_string (writebuf),
core_addr_to_string_nz (offset),
pulongest (len), retval,
pulongest (*xfered_len));
if (readbuf)
myaddr = readbuf;
if (writebuf)
myaddr = writebuf;
if (retval == TARGET_XFER_OK && myaddr != NULL)
{
int i;
fputs_unfiltered (", bytes =", gdb_stdlog);
for (i = 0; i < *xfered_len; i++)
{
if ((((intptr_t) &(myaddr[i])) & 0xf) == 0)
{
if (targetdebug < 2 && i > 0)
{
fprintf_unfiltered (gdb_stdlog, " ...");
break;
}
fprintf_unfiltered (gdb_stdlog, "\n");
}
fprintf_unfiltered (gdb_stdlog, " %02x", myaddr[i] & 0xff);
}
}
fputc_unfiltered ('\n', gdb_stdlog);
}
/* Check implementations of to_xfer_partial update *XFERED_LEN
properly. Do assertion after printing debug messages, so that we
can find more clues on assertion failure from debugging messages. */
if (retval == TARGET_XFER_OK || retval == TARGET_XFER_UNAVAILABLE)
gdb_assert (*xfered_len > 0);
return retval;
}
/* Read LEN bytes of target memory at address MEMADDR, placing the
results in GDB's memory at MYADDR. Returns either 0 for success or
-1 if any error occurs.
If an error occurs, no guarantee is made about the contents of the data at
MYADDR. In particular, the caller should not depend upon partial reads
filling the buffer with good data. There is no way for the caller to know
how much good data might have been transfered anyway. Callers that can
deal with partial reads should call target_read (which will retry until
it makes no progress, and then return how much was transferred). */
int
target_read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
{
if (target_read (current_top_target (), TARGET_OBJECT_MEMORY, NULL,
myaddr, memaddr, len) == len)
return 0;
else
return -1;
}
/* See target/target.h. */
int
target_read_uint32 (CORE_ADDR memaddr, uint32_t *result)
{
gdb_byte buf[4];
int r;
r = target_read_memory (memaddr, buf, sizeof buf);
if (r != 0)
return r;
*result = extract_unsigned_integer (buf, sizeof buf,
gdbarch_byte_order (target_gdbarch ()));
return 0;
}
/* Like target_read_memory, but specify explicitly that this is a read
from the target's raw memory. That is, this read bypasses the
dcache, breakpoint shadowing, etc. */
int
target_read_raw_memory (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
{
if (target_read (current_top_target (), TARGET_OBJECT_RAW_MEMORY, NULL,
myaddr, memaddr, len) == len)
return 0;
else
return -1;
}
/* Like target_read_memory, but specify explicitly that this is a read from
the target's stack. This may trigger different cache behavior. */
int
target_read_stack (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
{
if (target_read (current_top_target (), TARGET_OBJECT_STACK_MEMORY, NULL,
myaddr, memaddr, len) == len)
return 0;
else
return -1;
}
/* Like target_read_memory, but specify explicitly that this is a read from
the target's code. This may trigger different cache behavior. */
int
target_read_code (CORE_ADDR memaddr, gdb_byte *myaddr, ssize_t len)
{
if (target_read (current_top_target (), TARGET_OBJECT_CODE_MEMORY, NULL,
myaddr, memaddr, len) == len)
return 0;
else
return -1;
}
/* Write LEN bytes from MYADDR to target memory at address MEMADDR.
Returns either 0 for success or -1 if any error occurs. If an
error occurs, no guarantee is made about how much data got written.
Callers that can deal with partial writes should call
target_write. */
int
target_write_memory (CORE_ADDR memaddr, const gdb_byte *myaddr, ssize_t len)
{
if (target_write (current_top_target (), TARGET_OBJECT_MEMORY, NULL,
myaddr, memaddr, len) == len)
return 0;
else
return -1;
}
/* Write LEN bytes from MYADDR to target raw memory at address
MEMADDR. Returns either 0 for success or -1 if any error occurs.
If an error occurs, no guarantee is made about how much data got
written. Callers that can deal with partial writes should call
target_write. */
int
target_write_raw_memory (CORE_ADDR memaddr, const gdb_byte *myaddr, ssize_t len)
{
if (target_write (current_top_target (), TARGET_OBJECT_RAW_MEMORY, NULL,
myaddr, memaddr, len) == len)
return 0;
else
return -1;
}
/* Fetch the target's memory map. */
std::vector<mem_region>
target_memory_map (void)
{
std::vector<mem_region> result = current_top_target ()->memory_map ();
if (result.empty ())
return result;
std::sort (result.begin (), result.end ());
/* Check that regions do not overlap. Simultaneously assign
a numbering for the "mem" commands to use to refer to
each region. */
mem_region *last_one = NULL;
for (size_t ix = 0; ix < result.size (); ix++)
{
mem_region *this_one = &result[ix];
this_one->number = ix;
if (last_one != NULL && last_one->hi > this_one->lo)
{
warning (_("Overlapping regions in memory map: ignoring"));
return std::vector<mem_region> ();
}
last_one = this_one;
}
return result;
}
void
target_flash_erase (ULONGEST address, LONGEST length)
{
current_top_target ()->flash_erase (address, length);
}
void
target_flash_done (void)
{
current_top_target ()->flash_done ();
}
static void
show_trust_readonly (struct ui_file *file, int from_tty,
struct cmd_list_element *c, const char *value)
{
fprintf_filtered (file,
_("Mode for reading from readonly sections is %s.\n"),
value);
}
/* Target vector read/write partial wrapper functions. */
static enum target_xfer_status
target_read_partial (struct target_ops *ops,
enum target_object object,
const char *annex, gdb_byte *buf,
ULONGEST offset, ULONGEST len,
ULONGEST *xfered_len)
{
return target_xfer_partial (ops, object, annex, buf, NULL, offset, len,
xfered_len);
}
static enum target_xfer_status
target_write_partial (struct target_ops *ops,
enum target_object object,
const char *annex, const gdb_byte *buf,
ULONGEST offset, LONGEST len, ULONGEST *xfered_len)
{
return target_xfer_partial (ops, object, annex, NULL, buf, offset, len,
xfered_len);
}
/* Wrappers to perform the full transfer. */
/* For docs on target_read see target.h. */
LONGEST
target_read (struct target_ops *ops,
enum target_object object,
const char *annex, gdb_byte *buf,
ULONGEST offset, LONGEST len)
{
LONGEST xfered_total = 0;
int unit_size = 1;
/* If we are reading from a memory object, find the length of an addressable
unit for that architecture. */
if (object == TARGET_OBJECT_MEMORY
|| object == TARGET_OBJECT_STACK_MEMORY
|| object == TARGET_OBJECT_CODE_MEMORY
|| object == TARGET_OBJECT_RAW_MEMORY)
unit_size = gdbarch_addressable_memory_unit_size (target_gdbarch ());
while (xfered_total < len)
{
ULONGEST xfered_partial;
enum target_xfer_status status;
status = target_read_partial (ops, object, annex,
buf + xfered_total * unit_size,
offset + xfered_total, len - xfered_total,
&xfered_partial);
/* Call an observer, notifying them of the xfer progress? */
if (status == TARGET_XFER_EOF)
return xfered_total;
else if (status == TARGET_XFER_OK)
{
xfered_total += xfered_partial;
QUIT;
}
else
return TARGET_XFER_E_IO;
}
return len;
}
/* Assuming that the entire [begin, end) range of memory cannot be
read, try to read whatever subrange is possible to read.
The function returns, in RESULT, either zero or one memory block.
If there's a readable subrange at the beginning, it is completely
read and returned. Any further readable subrange will not be read.
Otherwise, if there's a readable subrange at the end, it will be
completely read and returned. Any readable subranges before it
(obviously, not starting at the beginning), will be ignored. In
other cases -- either no readable subrange, or readable subrange(s)
that is neither at the beginning, or end, nothing is returned.
The purpose of this function is to handle a read across a boundary
of accessible memory in a case when memory map is not available.
The above restrictions are fine for this case, but will give
incorrect results if the memory is 'patchy'. However, supporting
'patchy' memory would require trying to read every single byte,
and it seems unacceptable solution. Explicit memory map is
recommended for this case -- and target_read_memory_robust will
take care of reading multiple ranges then. */
static void
read_whatever_is_readable (struct target_ops *ops,
const ULONGEST begin, const ULONGEST end,
int unit_size,
std::vector<memory_read_result> *result)
{
ULONGEST current_begin = begin;
ULONGEST current_end = end;
int forward;
ULONGEST xfered_len;
/* If we previously failed to read 1 byte, nothing can be done here. */
if (end - begin <= 1)
return;
gdb::unique_xmalloc_ptr<gdb_byte> buf ((gdb_byte *) xmalloc (end - begin));
/* Check that either first or the last byte is readable, and give up
if not. This heuristic is meant to permit reading accessible memory
at the boundary of accessible region. */
if (target_read_partial (ops, TARGET_OBJECT_MEMORY, NULL,
buf.get (), begin, 1, &xfered_len) == TARGET_XFER_OK)
{
forward = 1;
++current_begin;
}
else if (target_read_partial (ops, TARGET_OBJECT_MEMORY, NULL,
buf.get () + (end - begin) - 1, end - 1, 1,
&xfered_len) == TARGET_XFER_OK)
{
forward = 0;
--current_end;
}
else
return;
/* Loop invariant is that the [current_begin, current_end) was previously
found to be not readable as a whole.
Note loop condition -- if the range has 1 byte, we can't divide the range
so there's no point trying further. */
while (current_end - current_begin > 1)
{
ULONGEST first_half_begin, first_half_end;
ULONGEST second_half_begin, second_half_end;
LONGEST xfer;
ULONGEST middle = current_begin + (current_end - current_begin) / 2;
if (forward)
{
first_half_begin = current_begin;
first_half_end = middle;
second_half_begin = middle;
second_half_end = current_end;
}
else
{
first_half_begin = middle;
first_half_end = current_end;
second_half_begin = current_begin;
second_half_end = middle;
}
xfer = target_read (ops, TARGET_OBJECT_MEMORY, NULL,
buf.get () + (first_half_begin - begin) * unit_size,
first_half_begin,
first_half_end - first_half_begin);
if (xfer == first_half_end - first_half_begin)
{
/* This half reads up fine. So, the error must be in the
other half. */
current_begin = second_half_begin;
current_end = second_half_end;
}
else
{
/* This half is not readable. Because we've tried one byte, we
know some part of this half if actually readable. Go to the next
iteration to divide again and try to read.
We don't handle the other half, because this function only tries
to read a single readable subrange. */
current_begin = first_half_begin;
current_end = first_half_end;
}
}
if (forward)
{
/* The [begin, current_begin) range has been read. */
result->emplace_back (begin, current_end, std::move (buf));
}
else
{
/* The [current_end, end) range has been read. */
LONGEST region_len = end - current_end;
gdb::unique_xmalloc_ptr<gdb_byte> data
((gdb_byte *) xmalloc (region_len * unit_size));
memcpy (data.get (), buf.get () + (current_end - begin) * unit_size,
region_len * unit_size);
result->emplace_back (current_end, end, std::move (data));
}
}
std::vector<memory_read_result>
read_memory_robust (struct target_ops *ops,
const ULONGEST offset, const LONGEST len)
{
std::vector<memory_read_result> result;
int unit_size = gdbarch_addressable_memory_unit_size (target_gdbarch ());
LONGEST xfered_total = 0;
while (xfered_total < len)
{
struct mem_region *region = lookup_mem_region (offset + xfered_total);
LONGEST region_len;
/* If there is no explicit region, a fake one should be created. */
gdb_assert (region);
if (region->hi == 0)
region_len = len - xfered_total;
else
region_len = region->hi - offset;
if (region->attrib.mode == MEM_NONE || region->attrib.mode == MEM_WO)
{
/* Cannot read this region. Note that we can end up here only
if the region is explicitly marked inaccessible, or
'inaccessible-by-default' is in effect. */
xfered_total += region_len;
}
else
{
LONGEST to_read = std::min (len - xfered_total, region_len);
gdb::unique_xmalloc_ptr<gdb_byte> buffer
((gdb_byte *) xmalloc (to_read * unit_size));
LONGEST xfered_partial =
target_read (ops, TARGET_OBJECT_MEMORY, NULL, buffer.get (),
offset + xfered_total, to_read);
/* Call an observer, notifying them of the xfer progress? */
if (xfered_partial <= 0)
{
/* Got an error reading full chunk. See if maybe we can read
some subrange. */
read_whatever_is_readable (ops, offset + xfered_total,
offset + xfered_total + to_read,
unit_size, &result);
xfered_total += to_read;
}
else
{
result.emplace_back (offset + xfered_total,
offset + xfered_total + xfered_partial,
std::move (buffer));
xfered_total += xfered_partial;
}
QUIT;
}
}
return result;
}
/* An alternative to target_write with progress callbacks. */
LONGEST
target_write_with_progress (struct target_ops *ops,
enum target_object object,
const char *annex, const gdb_byte *buf,
ULONGEST offset, LONGEST len,
void (*progress) (ULONGEST, void *), void *baton)
{
LONGEST xfered_total = 0;
int unit_size = 1;
/* If we are writing to a memory object, find the length of an addressable
unit for that architecture. */
if (object == TARGET_OBJECT_MEMORY
|| object == TARGET_OBJECT_STACK_MEMORY
|| object == TARGET_OBJECT_CODE_MEMORY
|| object == TARGET_OBJECT_RAW_MEMORY)
unit_size = gdbarch_addressable_memory_unit_size (target_gdbarch ());
/* Give the progress callback a chance to set up. */
if (progress)
(*progress) (0, baton);
while (xfered_total < len)
{
ULONGEST xfered_partial;
enum target_xfer_status status;
status = target_write_partial (ops, object, annex,
buf + xfered_total * unit_size,
offset + xfered_total, len - xfered_total,
&xfered_partial);
if (status != TARGET_XFER_OK)
return status == TARGET_XFER_EOF ? xfered_total : TARGET_XFER_E_IO;
if (progress)
(*progress) (xfered_partial, baton);
xfered_total += xfered_partial;
QUIT;
}
return len;
}
/* For docs on target_write see target.h. */
LONGEST
target_write (struct target_ops *ops,
enum target_object object,
const char *annex, const gdb_byte *buf,
ULONGEST offset, LONGEST len)
{
return target_write_with_progress (ops, object, annex, buf, offset, len,
NULL, NULL);
}
/* Help for target_read_alloc and target_read_stralloc. See their comments
for details. */
template <typename T>
gdb::optional<gdb::def_vector<T>>
target_read_alloc_1 (struct target_ops *ops, enum target_object object,
const char *annex)
{
gdb::def_vector<T> buf;
size_t buf_pos = 0;
const int chunk = 4096;
/* This function does not have a length parameter; it reads the
entire OBJECT). Also, it doesn't support objects fetched partly
from one target and partly from another (in a different stratum,
e.g. a core file and an executable). Both reasons make it
unsuitable for reading memory. */
gdb_assert (object != TARGET_OBJECT_MEMORY);
/* Start by reading up to 4K at a time. The target will throttle
this number down if necessary. */
while (1)
{
ULONGEST xfered_len;
enum target_xfer_status status;
buf.resize (buf_pos + chunk);
status = target_read_partial (ops, object, annex,
(gdb_byte *) &buf[buf_pos],
buf_pos, chunk,
&xfered_len);
if (status == TARGET_XFER_EOF)
{
/* Read all there was. */
buf.resize (buf_pos);
return buf;
}
else if (status != TARGET_XFER_OK)
{
/* An error occurred. */
return {};
}
buf_pos += xfered_len;
QUIT;
}
}
/* See target.h */
gdb::optional<gdb::byte_vector>
target_read_alloc (struct target_ops *ops, enum target_object object,
const char *annex)
{
return target_read_alloc_1<gdb_byte> (ops, object, annex);
}
/* See target.h. */
gdb::optional<gdb::char_vector>
target_read_stralloc (struct target_ops *ops, enum target_object object,
const char *annex)
{
gdb::optional<gdb::char_vector> buf
= target_read_alloc_1<char> (ops, object, annex);
if (!buf)
return {};
if (buf->empty () || buf->back () != '\0')
buf->push_back ('\0');
/* Check for embedded NUL bytes; but allow trailing NULs. */
for (auto it = std::find (buf->begin (), buf->end (), '\0');
it != buf->end (); it++)
if (*it != '\0')
{
warning (_("target object %d, annex %s, "
"contained unexpected null characters"),
(int) object, annex ? annex : "(none)");
break;
}
return buf;
}
/* Memory transfer methods. */
void
get_target_memory (struct target_ops *ops, CORE_ADDR addr, gdb_byte *buf,
LONGEST len)
{
/* This method is used to read from an alternate, non-current
target. This read must bypass the overlay support (as symbols
don't match this target), and GDB's internal cache (wrong cache
for this target). */
if (target_read (ops, TARGET_OBJECT_RAW_MEMORY, NULL, buf, addr, len)
!= len)
memory_error (TARGET_XFER_E_IO, addr);
}
ULONGEST
get_target_memory_unsigned (struct target_ops *ops, CORE_ADDR addr,
int len, enum bfd_endian byte_order)
{
gdb_byte buf[sizeof (ULONGEST)];
gdb_assert (len <= sizeof (buf));
get_target_memory (ops, addr, buf, len);
return extract_unsigned_integer (buf, len, byte_order);
}
/* See target.h. */
int
target_insert_breakpoint (struct gdbarch *gdbarch,
struct bp_target_info *bp_tgt)
{
if (!may_insert_breakpoints)
{
warning (_("May not insert breakpoints"));
return 1;
}
return current_top_target ()->insert_breakpoint (gdbarch, bp_tgt);
}
/* See target.h. */
int
target_remove_breakpoint (struct gdbarch *gdbarch,
struct bp_target_info *bp_tgt,
enum remove_bp_reason reason)
{
/* This is kind of a weird case to handle, but the permission might
have been changed after breakpoints were inserted - in which case
we should just take the user literally and assume that any
breakpoints should be left in place. */
if (!may_insert_breakpoints)
{
warning (_("May not remove breakpoints"));
return 1;
}
return current_top_target ()->remove_breakpoint (gdbarch, bp_tgt, reason);
}
static void
info_target_command (const char *args, int from_tty)
{
int has_all_mem = 0;
if (symfile_objfile != NULL)
printf_unfiltered (_("Symbols from \"%s\".\n"),
objfile_name (symfile_objfile));
for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
{
if (!t->has_memory ())
continue;
if ((int) (t->stratum ()) <= (int) dummy_stratum)
continue;
if (has_all_mem)
printf_unfiltered (_("\tWhile running this, "
"GDB does not access memory from...\n"));
printf_unfiltered ("%s:\n", t->longname ());
t->files_info ();
has_all_mem = t->has_all_memory ();
}
}
/* This function is called before any new inferior is created, e.g.
by running a program, attaching, or connecting to a target.
It cleans up any state from previous invocations which might
change between runs. This is a subset of what target_preopen
resets (things which might change between targets). */
void
target_pre_inferior (int from_tty)
{
/* Clear out solib state. Otherwise the solib state of the previous
inferior might have survived and is entirely wrong for the new
target. This has been observed on GNU/Linux using glibc 2.3. How
to reproduce:
bash$ ./foo&
[1] 4711
bash$ ./foo&
[1] 4712
bash$ gdb ./foo
[...]
(gdb) attach 4711
(gdb) detach
(gdb) attach 4712
Cannot access memory at address 0xdeadbeef
*/
/* In some OSs, the shared library list is the same/global/shared
across inferiors. If code is shared between processes, so are
memory regions and features. */
if (!gdbarch_has_global_solist (target_gdbarch ()))
{
no_shared_libraries (NULL, from_tty);
invalidate_target_mem_regions ();
target_clear_description ();
}
/* attach_flag may be set if the previous process associated with
the inferior was attached to. */
current_inferior ()->attach_flag = 0;
current_inferior ()->highest_thread_num = 0;
agent_capability_invalidate ();
}
/* Callback for iterate_over_inferiors. Gets rid of the given
inferior. */
static int
dispose_inferior (struct inferior *inf, void *args)
{
/* Not all killed inferiors can, or will ever be, removed from the
inferior list. Killed inferiors clearly don't need to be killed
again, so, we're done. */
if (inf->pid == 0)
return 0;
thread_info *thread = any_thread_of_inferior (inf);
if (thread != NULL)
{
switch_to_thread (thread);
/* Core inferiors actually should be detached, not killed. */
if (target_has_execution)
target_kill ();
else
target_detach (inf, 0);
}
return 0;
}
/* This is to be called by the open routine before it does
anything. */
void
target_preopen (int from_tty)
{
dont_repeat ();
if (have_inferiors ())
{
if (!from_tty
|| !have_live_inferiors ()
|| query (_("A program is being debugged already. Kill it? ")))
iterate_over_inferiors (dispose_inferior, NULL);
else
error (_("Program not killed."));
}
/* Calling target_kill may remove the target from the stack. But if
it doesn't (which seems like a win for UDI), remove it now. */
/* Leave the exec target, though. The user may be switching from a
live process to a core of the same program. */
pop_all_targets_above (file_stratum);
target_pre_inferior (from_tty);
}
/* See target.h. */
void
target_detach (inferior *inf, int from_tty)
{
/* After we have detached, we will clear the register cache for this inferior
by calling registers_changed_ptid. We must save the pid_ptid before
detaching, as the target detach method will clear inf->pid. */
ptid_t save_pid_ptid = ptid_t (inf->pid);
/* As long as some to_detach implementations rely on the current_inferior
(either directly, or indirectly, like through target_gdbarch or by
reading memory), INF needs to be the current inferior. When that
requirement will become no longer true, then we can remove this
assertion. */
gdb_assert (inf == current_inferior ());
if (gdbarch_has_global_breakpoints (target_gdbarch ()))
/* Don't remove global breakpoints here. They're removed on
disconnection from the target. */
;
else
/* If we're in breakpoints-always-inserted mode, have to remove
breakpoints before detaching. */
remove_breakpoints_inf (current_inferior ());
prepare_for_detach ();
current_top_target ()->detach (inf, from_tty);
registers_changed_ptid (save_pid_ptid);
/* We have to ensure we have no frame cache left. Normally,
registers_changed_ptid (save_pid_ptid) calls reinit_frame_cache when
inferior_ptid matches save_pid_ptid, but in our case, it does not
call it, as inferior_ptid has been reset. */
reinit_frame_cache ();
}
void
target_disconnect (const char *args, int from_tty)
{
/* If we're in breakpoints-always-inserted mode or if breakpoints
are global across processes, we have to remove them before
disconnecting. */
remove_breakpoints ();
current_top_target ()->disconnect (args, from_tty);
}
/* See target/target.h. */
ptid_t
target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
{
return current_top_target ()->wait (ptid, status, options);
}
/* See target.h. */
ptid_t
default_target_wait (struct target_ops *ops,
ptid_t ptid, struct target_waitstatus *status,
int options)
{
status->kind = TARGET_WAITKIND_IGNORE;
return minus_one_ptid;
}
std::string
target_pid_to_str (ptid_t ptid)
{
return current_top_target ()->pid_to_str (ptid);
}
const char *
target_thread_name (struct thread_info *info)
{
return current_top_target ()->thread_name (info);
}
struct thread_info *
target_thread_handle_to_thread_info (const gdb_byte *thread_handle,
int handle_len,
struct inferior *inf)
{
return current_top_target ()->thread_handle_to_thread_info (thread_handle,
handle_len, inf);
}
/* See target.h. */
gdb::byte_vector
target_thread_info_to_thread_handle (struct thread_info *tip)
{
return current_top_target ()->thread_info_to_thread_handle (tip);
}
void
target_resume (ptid_t ptid, int step, enum gdb_signal signal)
{
target_dcache_invalidate ();
current_top_target ()->resume (ptid, step, signal);
registers_changed_ptid (ptid);
/* We only set the internal executing state here. The user/frontend
running state is set at a higher level. This also clears the
thread's stop_pc as side effect. */
set_executing (ptid, 1);
clear_inline_frame_state (ptid);
}
/* If true, target_commit_resume is a nop. */
static int defer_target_commit_resume;
/* See target.h. */
void
target_commit_resume (void)
{
if (defer_target_commit_resume)
return;
current_top_target ()->commit_resume ();
}
/* See target.h. */
scoped_restore_tmpl<int>
make_scoped_defer_target_commit_resume ()
{
return make_scoped_restore (&defer_target_commit_resume, 1);
}
void
target_pass_signals (gdb::array_view<const unsigned char> pass_signals)
{
current_top_target ()->pass_signals (pass_signals);
}
void
target_program_signals (gdb::array_view<const unsigned char> program_signals)
{
current_top_target ()->program_signals (program_signals);
}
static int
default_follow_fork (struct target_ops *self, int follow_child,
int detach_fork)
{
/* Some target returned a fork event, but did not know how to follow it. */
internal_error (__FILE__, __LINE__,
_("could not find a target to follow fork"));
}
/* Look through the list of possible targets for a target that can
follow forks. */
int
target_follow_fork (int follow_child, int detach_fork)
{
return current_top_target ()->follow_fork (follow_child, detach_fork);
}
/* Target wrapper for follow exec hook. */
void
target_follow_exec (struct inferior *inf, const char *execd_pathname)
{
current_top_target ()->follow_exec (inf, execd_pathname);
}
static void
default_mourn_inferior (struct target_ops *self)
{
internal_error (__FILE__, __LINE__,
_("could not find a target to follow mourn inferior"));
}
void
target_mourn_inferior (ptid_t ptid)
{
gdb_assert (ptid == inferior_ptid);
current_top_target ()->mourn_inferior ();
/* We no longer need to keep handles on any of the object files.
Make sure to release them to avoid unnecessarily locking any
of them while we're not actually debugging. */
bfd_cache_close_all ();
}
/* Look for a target which can describe architectural features, starting
from TARGET. If we find one, return its description. */
const struct target_desc *
target_read_description (struct target_ops *target)
{
return target->read_description ();
}
/* This implements a basic search of memory, reading target memory and
performing the search here (as opposed to performing the search in on the
target side with, for example, gdbserver). */
int
simple_search_memory (struct target_ops *ops,
CORE_ADDR start_addr, ULONGEST search_space_len,
const gdb_byte *pattern, ULONGEST pattern_len,
CORE_ADDR *found_addrp)
{
/* NOTE: also defined in find.c testcase. */
#define SEARCH_CHUNK_SIZE 16000
const unsigned chunk_size = SEARCH_CHUNK_SIZE;
/* Buffer to hold memory contents for searching. */
unsigned search_buf_size;
search_buf_size = chunk_size + pattern_len - 1;
/* No point in trying to allocate a buffer larger than the search space. */
if (search_space_len < search_buf_size)
search_buf_size = search_space_len;
gdb::byte_vector search_buf (search_buf_size);
/* Prime the search buffer. */
if (target_read (ops, TARGET_OBJECT_MEMORY, NULL,
search_buf.data (), start_addr, search_buf_size)
!= search_buf_size)
{
warning (_("Unable to access %s bytes of target "
"memory at %s, halting search."),
pulongest (search_buf_size), hex_string (start_addr));
return -1;
}
/* Perform the search.
The loop is kept simple by allocating [N + pattern-length - 1] bytes.
When we've scanned N bytes we copy the trailing bytes to the start and
read in another N bytes. */
while (search_space_len >= pattern_len)
{
gdb_byte *found_ptr;
unsigned nr_search_bytes
= std::min (search_space_len, (ULONGEST) search_buf_size);
found_ptr = (gdb_byte *) memmem (search_buf.data (), nr_search_bytes,
pattern, pattern_len);
if (found_ptr != NULL)
{
CORE_ADDR found_addr = start_addr + (found_ptr - search_buf.data ());
*found_addrp = found_addr;
return 1;
}
/* Not found in this chunk, skip to next chunk. */
/* Don't let search_space_len wrap here, it's unsigned. */
if (search_space_len >= chunk_size)
search_space_len -= chunk_size;
else
search_space_len = 0;
if (search_space_len >= pattern_len)
{
unsigned keep_len = search_buf_size - chunk_size;
CORE_ADDR read_addr = start_addr + chunk_size + keep_len;
int nr_to_read;
/* Copy the trailing part of the previous iteration to the front
of the buffer for the next iteration. */
gdb_assert (keep_len == pattern_len - 1);
memcpy (&search_buf[0], &search_buf[chunk_size], keep_len);
nr_to_read = std::min (search_space_len - keep_len,
(ULONGEST) chunk_size);
if (target_read (ops, TARGET_OBJECT_MEMORY, NULL,
&search_buf[keep_len], read_addr,
nr_to_read) != nr_to_read)
{
warning (_("Unable to access %s bytes of target "
"memory at %s, halting search."),
plongest (nr_to_read),
hex_string (read_addr));
return -1;
}
start_addr += chunk_size;
}
}
/* Not found. */
return 0;
}
/* Default implementation of memory-searching. */
static int
default_search_memory (struct target_ops *self,
CORE_ADDR start_addr, ULONGEST search_space_len,
const gdb_byte *pattern, ULONGEST pattern_len,
CORE_ADDR *found_addrp)
{
/* Start over from the top of the target stack. */
return simple_search_memory (current_top_target (),
start_addr, search_space_len,
pattern, pattern_len, found_addrp);
}
/* Search SEARCH_SPACE_LEN bytes beginning at START_ADDR for the
sequence of bytes in PATTERN with length PATTERN_LEN.
The result is 1 if found, 0 if not found, and -1 if there was an error
requiring halting of the search (e.g. memory read error).
If the pattern is found the address is recorded in FOUND_ADDRP. */
int
target_search_memory (CORE_ADDR start_addr, ULONGEST search_space_len,
const gdb_byte *pattern, ULONGEST pattern_len,
CORE_ADDR *found_addrp)
{
return current_top_target ()->search_memory (start_addr, search_space_len,
pattern, pattern_len, found_addrp);
}
/* Look through the currently pushed targets. If none of them will
be able to restart the currently running process, issue an error
message. */
void
target_require_runnable (void)
{
for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
{
/* If this target knows how to create a new program, then
assume we will still be able to after killing the current
one. Either killing and mourning will not pop T, or else
find_default_run_target will find it again. */
if (t->can_create_inferior ())
return;
/* Do not worry about targets at certain strata that can not
create inferiors. Assume they will be pushed again if
necessary, and continue to the process_stratum. */
if (t->stratum () > process_stratum)
continue;
error (_("The \"%s\" target does not support \"run\". "
"Try \"help target\" or \"continue\"."),
t->shortname ());
}
/* This function is only called if the target is running. In that
case there should have been a process_stratum target and it
should either know how to create inferiors, or not... */
internal_error (__FILE__, __LINE__, _("No targets found"));
}
/* Whether GDB is allowed to fall back to the default run target for
"run", "attach", etc. when no target is connected yet. */
static bool auto_connect_native_target = true;
static void
show_auto_connect_native_target (struct ui_file *file, int from_tty,
struct cmd_list_element *c, const char *value)
{
fprintf_filtered (file,
_("Whether GDB may automatically connect to the "
"native target is %s.\n"),
value);
}
/* A pointer to the target that can respond to "run" or "attach".
Native targets are always singletons and instantiated early at GDB
startup. */
static target_ops *the_native_target;
/* See target.h. */
void
set_native_target (target_ops *target)
{
if (the_native_target != NULL)
internal_error (__FILE__, __LINE__,
_("native target already set (\"%s\")."),
the_native_target->longname ());
the_native_target = target;
}
/* See target.h. */
target_ops *
get_native_target ()
{
return the_native_target;
}
/* Look through the list of possible targets for a target that can
execute a run or attach command without any other data. This is
used to locate the default process stratum.
If DO_MESG is not NULL, the result is always valid (error() is
called for errors); else, return NULL on error. */
static struct target_ops *
find_default_run_target (const char *do_mesg)
{
if (auto_connect_native_target && the_native_target != NULL)
return the_native_target;
if (do_mesg != NULL)
error (_("Don't know how to %s. Try \"help target\"."), do_mesg);
return NULL;
}
/* See target.h. */
struct target_ops *
find_attach_target (void)
{
/* If a target on the current stack can attach, use it. */
for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
{
if (t->can_attach ())
return t;
}
/* Otherwise, use the default run target for attaching. */
return find_default_run_target ("attach");
}
/* See target.h. */
struct target_ops *
find_run_target (void)
{
/* If a target on the current stack can run, use it. */
for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
{
if (t->can_create_inferior ())
return t;
}
/* Otherwise, use the default run target. */
return find_default_run_target ("run");
}
bool
target_ops::info_proc (const char *args, enum info_proc_what what)
{
return false;
}
/* Implement the "info proc" command. */
int
target_info_proc (const char *args, enum info_proc_what what)
{
struct target_ops *t;
/* If we're already connected to something that can get us OS
related data, use it. Otherwise, try using the native
target. */
t = find_target_at (process_stratum);
if (t == NULL)
t = find_default_run_target (NULL);
for (; t != NULL; t = t->beneath ())
{
if (t->info_proc (args, what))
{
if (targetdebug)
fprintf_unfiltered (gdb_stdlog,
"target_info_proc (\"%s\", %d)\n", args, what);
return 1;
}
}
return 0;
}
static int
find_default_supports_disable_randomization (struct target_ops *self)
{
struct target_ops *t;
t = find_default_run_target (NULL);
if (t != NULL)
return t->supports_disable_randomization ();
return 0;
}
int
target_supports_disable_randomization (void)
{
return current_top_target ()->supports_disable_randomization ();
}
/* See target/target.h. */
int
target_supports_multi_process (void)
{
return current_top_target ()->supports_multi_process ();
}
/* See target.h. */
gdb::optional<gdb::char_vector>
target_get_osdata (const char *type)
{
struct target_ops *t;
/* If we're already connected to something that can get us OS
related data, use it. Otherwise, try using the native
target. */
t = find_target_at (process_stratum);
if (t == NULL)
t = find_default_run_target ("get OS data");
if (!t)
return {};
return target_read_stralloc (t, TARGET_OBJECT_OSDATA, type);
}
/* Determine the current address space of thread PTID. */
struct address_space *
target_thread_address_space (ptid_t ptid)
{
struct address_space *aspace;
aspace = current_top_target ()->thread_address_space (ptid);
gdb_assert (aspace != NULL);
return aspace;
}
/* See target.h. */
target_ops *
target_ops::beneath () const
{
return g_target_stack.find_beneath (this);
}
void
target_ops::close ()
{
}
bool
target_ops::can_attach ()
{
return 0;
}
void
target_ops::attach (const char *, int)
{
gdb_assert_not_reached ("target_ops::attach called");
}
bool
target_ops::can_create_inferior ()
{
return 0;
}
void
target_ops::create_inferior (const char *, const std::string &,
char **, int)
{
gdb_assert_not_reached ("target_ops::create_inferior called");
}
bool
target_ops::can_run ()
{
return false;
}
int
target_can_run ()
{
for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
{
if (t->can_run ())
return 1;
}
return 0;
}
/* Target file operations. */
static struct target_ops *
default_fileio_target (void)
{
struct target_ops *t;
/* If we're already connected to something that can perform
file I/O, use it. Otherwise, try using the native target. */
t = find_target_at (process_stratum);
if (t != NULL)
return t;
return find_default_run_target ("file I/O");
}
/* File handle for target file operations. */
struct fileio_fh_t
{
/* The target on which this file is open. NULL if the target is
meanwhile closed while the handle is open. */
target_ops *target;
/* The file descriptor on the target. */
int target_fd;
/* Check whether this fileio_fh_t represents a closed file. */
bool is_closed ()
{
return target_fd < 0;
}
};
/* Vector of currently open file handles. The value returned by
target_fileio_open and passed as the FD argument to other
target_fileio_* functions is an index into this vector. This
vector's entries are never freed; instead, files are marked as
closed, and the handle becomes available for reuse. */
static std::vector<fileio_fh_t> fileio_fhandles;
/* Index into fileio_fhandles of the lowest handle that might be
closed. This permits handle reuse without searching the whole
list each time a new file is opened. */
static int lowest_closed_fd;
/* Invalidate the target associated with open handles that were open
on target TARG, since we're about to close (and maybe destroy) the
target. The handles remain open from the client's perspective, but
trying to do anything with them other than closing them will fail
with EIO. */
static void
fileio_handles_invalidate_target (target_ops *targ)
{
for (fileio_fh_t &fh : fileio_fhandles)
if (fh.target == targ)
fh.target = NULL;
}
/* Acquire a target fileio file descriptor. */
static int
acquire_fileio_fd (target_ops *target, int target_fd)
{
/* Search for closed handles to reuse. */
for (; lowest_closed_fd < fileio_fhandles.size (); lowest_closed_fd++)
{
fileio_fh_t &fh = fileio_fhandles[lowest_closed_fd];
if (fh.is_closed ())
break;
}
/* Push a new handle if no closed handles were found. */
if (lowest_closed_fd == fileio_fhandles.size ())
fileio_fhandles.push_back (fileio_fh_t {target, target_fd});
else
fileio_fhandles[lowest_closed_fd] = {target, target_fd};
/* Should no longer be marked closed. */
gdb_assert (!fileio_fhandles[lowest_closed_fd].is_closed ());
/* Return its index, and start the next lookup at
the next index. */
return lowest_closed_fd++;
}
/* Release a target fileio file descriptor. */
static void
release_fileio_fd (int fd, fileio_fh_t *fh)
{
fh->target_fd = -1;
lowest_closed_fd = std::min (lowest_closed_fd, fd);
}
/* Return a pointer to the fileio_fhandle_t corresponding to FD. */
static fileio_fh_t *
fileio_fd_to_fh (int fd)
{
return &fileio_fhandles[fd];
}
/* Default implementations of file i/o methods. We don't want these
to delegate automatically, because we need to know which target
supported the method, in order to call it directly from within
pread/pwrite, etc. */
int
target_ops::fileio_open (struct inferior *inf, const char *filename,
int flags, int mode, int warn_if_slow,
int *target_errno)
{
*target_errno = FILEIO_ENOSYS;
return -1;
}
int
target_ops::fileio_pwrite (int fd, const gdb_byte *write_buf, int len,
ULONGEST offset, int *target_errno)
{
*target_errno = FILEIO_ENOSYS;
return -1;
}
int
target_ops::fileio_pread (int fd, gdb_byte *read_buf, int len,
ULONGEST offset, int *target_errno)
{
*target_errno = FILEIO_ENOSYS;
return -1;
}
int
target_ops::fileio_fstat (int fd, struct stat *sb, int *target_errno)
{
*target_errno = FILEIO_ENOSYS;
return -1;
}
int
target_ops::fileio_close (int fd, int *target_errno)
{
*target_errno = FILEIO_ENOSYS;
return -1;
}
int
target_ops::fileio_unlink (struct inferior *inf, const char *filename,
int *target_errno)
{
*target_errno = FILEIO_ENOSYS;
return -1;
}
gdb::optional<std::string>
target_ops::fileio_readlink (struct inferior *inf, const char *filename,
int *target_errno)
{
*target_errno = FILEIO_ENOSYS;
return {};
}
/* Helper for target_fileio_open and
target_fileio_open_warn_if_slow. */
static int
target_fileio_open_1 (struct inferior *inf, const char *filename,
int flags, int mode, int warn_if_slow,
int *target_errno)
{
for (target_ops *t = default_fileio_target (); t != NULL; t = t->beneath ())
{
int fd = t->fileio_open (inf, filename, flags, mode,
warn_if_slow, target_errno);
if (fd == -1 && *target_errno == FILEIO_ENOSYS)
continue;
if (fd < 0)
fd = -1;
else
fd = acquire_fileio_fd (t, fd);
if (targetdebug)
fprintf_unfiltered (gdb_stdlog,
"target_fileio_open (%d,%s,0x%x,0%o,%d)"
" = %d (%d)\n",
inf == NULL ? 0 : inf->num,
filename, flags, mode,
warn_if_slow, fd,
fd != -1 ? 0 : *target_errno);
return fd;
}
*target_errno = FILEIO_ENOSYS;
return -1;
}
/* See target.h. */
int
target_fileio_open (struct inferior *inf, const char *filename,
int flags, int mode, int *target_errno)
{
return target_fileio_open_1 (inf, filename, flags, mode, 0,
target_errno);
}
/* See target.h. */
int
target_fileio_open_warn_if_slow (struct inferior *inf,
const char *filename,
int flags, int mode, int *target_errno)
{
return target_fileio_open_1 (inf, filename, flags, mode, 1,
target_errno);
}
/* See target.h. */
int
target_fileio_pwrite (int fd, const gdb_byte *write_buf, int len,
ULONGEST offset, int *target_errno)
{
fileio_fh_t *fh = fileio_fd_to_fh (fd);
int ret = -1;
if (fh->is_closed ())
*target_errno = EBADF;
else if (fh->target == NULL)
*target_errno = EIO;
else
ret = fh->target->fileio_pwrite (fh->target_fd, write_buf,
len, offset, target_errno);
if (targetdebug)
fprintf_unfiltered (gdb_stdlog,
"target_fileio_pwrite (%d,...,%d,%s) "
"= %d (%d)\n",
fd, len, pulongest (offset),
ret, ret != -1 ? 0 : *target_errno);
return ret;
}
/* See target.h. */
int
target_fileio_pread (int fd, gdb_byte *read_buf, int len,
ULONGEST offset, int *target_errno)
{
fileio_fh_t *fh = fileio_fd_to_fh (fd);
int ret = -1;
if (fh->is_closed ())
*target_errno = EBADF;
else if (fh->target == NULL)
*target_errno = EIO;
else
ret = fh->target->fileio_pread (fh->target_fd, read_buf,
len, offset, target_errno);
if (targetdebug)
fprintf_unfiltered (gdb_stdlog,
"target_fileio_pread (%d,...,%d,%s) "
"= %d (%d)\n",
fd, len, pulongest (offset),
ret, ret != -1 ? 0 : *target_errno);
return ret;
}
/* See target.h. */
int
target_fileio_fstat (int fd, struct stat *sb, int *target_errno)
{
fileio_fh_t *fh = fileio_fd_to_fh (fd);
int ret = -1;
if (fh->is_closed ())
*target_errno = EBADF;
else if (fh->target == NULL)
*target_errno = EIO;
else
ret = fh->target->fileio_fstat (fh->target_fd, sb, target_errno);
if (targetdebug)
fprintf_unfiltered (gdb_stdlog,
"target_fileio_fstat (%d) = %d (%d)\n",
fd, ret, ret != -1 ? 0 : *target_errno);
return ret;
}
/* See target.h. */
int
target_fileio_close (int fd, int *target_errno)
{
fileio_fh_t *fh = fileio_fd_to_fh (fd);
int ret = -1;
if (fh->is_closed ())
*target_errno = EBADF;
else
{
if (fh->target != NULL)
ret = fh->target->fileio_close (fh->target_fd,
target_errno);
else
ret = 0;
release_fileio_fd (fd, fh);
}
if (targetdebug)
fprintf_unfiltered (gdb_stdlog,
"target_fileio_close (%d) = %d (%d)\n",
fd, ret, ret != -1 ? 0 : *target_errno);
return ret;
}
/* See target.h. */
int
target_fileio_unlink (struct inferior *inf, const char *filename,
int *target_errno)
{
for (target_ops *t = default_fileio_target (); t != NULL; t = t->beneath ())
{
int ret = t->fileio_unlink (inf, filename, target_errno);
if (ret == -1 && *target_errno == FILEIO_ENOSYS)
continue;
if (targetdebug)
fprintf_unfiltered (gdb_stdlog,
"target_fileio_unlink (%d,%s)"
" = %d (%d)\n",
inf == NULL ? 0 : inf->num, filename,
ret, ret != -1 ? 0 : *target_errno);
return ret;
}
*target_errno = FILEIO_ENOSYS;
return -1;
}
/* See target.h. */
gdb::optional<std::string>
target_fileio_readlink (struct inferior *inf, const char *filename,
int *target_errno)
{
for (target_ops *t = default_fileio_target (); t != NULL; t = t->beneath ())
{
gdb::optional<std::string> ret
= t->fileio_readlink (inf, filename, target_errno);
if (!ret.has_value () && *target_errno == FILEIO_ENOSYS)
continue;
if (targetdebug)
fprintf_unfiltered (gdb_stdlog,
"target_fileio_readlink (%d,%s)"
" = %s (%d)\n",
inf == NULL ? 0 : inf->num,
filename, ret ? ret->c_str () : "(nil)",
ret ? 0 : *target_errno);
return ret;
}
*target_errno = FILEIO_ENOSYS;
return {};
}
/* Like scoped_fd, but specific to target fileio. */
class scoped_target_fd
{
public:
explicit scoped_target_fd (int fd) noexcept
: m_fd (fd)
{
}
~scoped_target_fd ()
{
if (m_fd >= 0)
{
int target_errno;
target_fileio_close (m_fd, &target_errno);
}
}
DISABLE_COPY_AND_ASSIGN (scoped_target_fd);
int get () const noexcept
{
return m_fd;
}
private:
int m_fd;
};
/* Read target file FILENAME, in the filesystem as seen by INF. If
INF is NULL, use the filesystem seen by the debugger (GDB or, for
remote targets, the remote stub). Store the result in *BUF_P and
return the size of the transferred data. PADDING additional bytes
are available in *BUF_P. This is a helper function for
target_fileio_read_alloc; see the declaration of that function for
more information. */
static LONGEST
target_fileio_read_alloc_1 (struct inferior *inf,