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linux-tdep.c
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linux-tdep.c
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/* Target-dependent code for GNU/Linux, architecture independent.
Copyright (C) 2009-2022 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "gdbtypes.h"
#include "linux-tdep.h"
#include "auxv.h"
#include "target.h"
#include "gdbthread.h"
#include "gdbcore.h"
#include "regcache.h"
#include "regset.h"
#include "elf/common.h"
#include "elf-bfd.h" /* for elfcore_write_* */
#include "inferior.h"
#include "cli/cli-utils.h"
#include "arch-utils.h"
#include "gdbsupport/gdb_obstack.h"
#include "observable.h"
#include "objfiles.h"
#include "infcall.h"
#include "gdbcmd.h"
#include "gdbsupport/gdb_regex.h"
#include "gdbsupport/enum-flags.h"
#include "gdbsupport/gdb_optional.h"
#include "gcore.h"
#include "gcore-elf.h"
#include "solib-svr4.h"
#include <ctype.h>
/* This enum represents the values that the user can choose when
informing the Linux kernel about which memory mappings will be
dumped in a corefile. They are described in the file
Documentation/filesystems/proc.txt, inside the Linux kernel
tree. */
enum filter_flag
{
COREFILTER_ANON_PRIVATE = 1 << 0,
COREFILTER_ANON_SHARED = 1 << 1,
COREFILTER_MAPPED_PRIVATE = 1 << 2,
COREFILTER_MAPPED_SHARED = 1 << 3,
COREFILTER_ELF_HEADERS = 1 << 4,
COREFILTER_HUGETLB_PRIVATE = 1 << 5,
COREFILTER_HUGETLB_SHARED = 1 << 6,
};
DEF_ENUM_FLAGS_TYPE (enum filter_flag, filter_flags);
/* This struct is used to map flags found in the "VmFlags:" field (in
the /proc/<PID>/smaps file). */
struct smaps_vmflags
{
/* Zero if this structure has not been initialized yet. It
probably means that the Linux kernel being used does not emit
the "VmFlags:" field on "/proc/PID/smaps". */
unsigned int initialized_p : 1;
/* Memory mapped I/O area (VM_IO, "io"). */
unsigned int io_page : 1;
/* Area uses huge TLB pages (VM_HUGETLB, "ht"). */
unsigned int uses_huge_tlb : 1;
/* Do not include this memory region on the coredump (VM_DONTDUMP, "dd"). */
unsigned int exclude_coredump : 1;
/* Is this a MAP_SHARED mapping (VM_SHARED, "sh"). */
unsigned int shared_mapping : 1;
/* Memory map has memory tagging enabled. */
unsigned int memory_tagging : 1;
};
/* Data structure that holds the information contained in the
/proc/<pid>/smaps file. */
struct smaps_data
{
ULONGEST start_address;
ULONGEST end_address;
std::string filename;
struct smaps_vmflags vmflags;
bool read;
bool write;
bool exec;
bool priv;
bool has_anonymous;
bool mapping_anon_p;
bool mapping_file_p;
ULONGEST inode;
ULONGEST offset;
};
/* Whether to take the /proc/PID/coredump_filter into account when
generating a corefile. */
static bool use_coredump_filter = true;
/* Whether the value of smaps_vmflags->exclude_coredump should be
ignored, including mappings marked with the VM_DONTDUMP flag in
the dump. */
static bool dump_excluded_mappings = false;
/* This enum represents the signals' numbers on a generic architecture
running the Linux kernel. The definition of "generic" comes from
the file <include/uapi/asm-generic/signal.h>, from the Linux kernel
tree, which is the "de facto" implementation of signal numbers to
be used by new architecture ports.
For those architectures which have differences between the generic
standard (e.g., Alpha), we define the different signals (and *only*
those) in the specific target-dependent file (e.g.,
alpha-linux-tdep.c, for Alpha). Please refer to the architecture's
tdep file for more information.
ARM deserves a special mention here. On the file
<arch/arm/include/uapi/asm/signal.h>, it defines only one different
(and ARM-only) signal, which is SIGSWI, with the same number as
SIGRTMIN. This signal is used only for a very specific target,
called ArthurOS (from RISCOS). Therefore, we do not handle it on
the ARM-tdep file, and we can safely use the generic signal handler
here for ARM targets.
As stated above, this enum is derived from
<include/uapi/asm-generic/signal.h>, from the Linux kernel
tree. */
enum
{
LINUX_SIGHUP = 1,
LINUX_SIGINT = 2,
LINUX_SIGQUIT = 3,
LINUX_SIGILL = 4,
LINUX_SIGTRAP = 5,
LINUX_SIGABRT = 6,
LINUX_SIGIOT = 6,
LINUX_SIGBUS = 7,
LINUX_SIGFPE = 8,
LINUX_SIGKILL = 9,
LINUX_SIGUSR1 = 10,
LINUX_SIGSEGV = 11,
LINUX_SIGUSR2 = 12,
LINUX_SIGPIPE = 13,
LINUX_SIGALRM = 14,
LINUX_SIGTERM = 15,
LINUX_SIGSTKFLT = 16,
LINUX_SIGCHLD = 17,
LINUX_SIGCONT = 18,
LINUX_SIGSTOP = 19,
LINUX_SIGTSTP = 20,
LINUX_SIGTTIN = 21,
LINUX_SIGTTOU = 22,
LINUX_SIGURG = 23,
LINUX_SIGXCPU = 24,
LINUX_SIGXFSZ = 25,
LINUX_SIGVTALRM = 26,
LINUX_SIGPROF = 27,
LINUX_SIGWINCH = 28,
LINUX_SIGIO = 29,
LINUX_SIGPOLL = LINUX_SIGIO,
LINUX_SIGPWR = 30,
LINUX_SIGSYS = 31,
LINUX_SIGUNUSED = 31,
LINUX_SIGRTMIN = 32,
LINUX_SIGRTMAX = 64,
};
static struct gdbarch_data *linux_gdbarch_data_handle;
struct linux_gdbarch_data
{
struct type *siginfo_type;
int num_disp_step_buffers;
};
static void *
init_linux_gdbarch_data (struct obstack *obstack)
{
return obstack_zalloc<linux_gdbarch_data> (obstack);
}
static struct linux_gdbarch_data *
get_linux_gdbarch_data (struct gdbarch *gdbarch)
{
return ((struct linux_gdbarch_data *)
gdbarch_data (gdbarch, linux_gdbarch_data_handle));
}
/* Linux-specific cached data. This is used by GDB for caching
purposes for each inferior. This helps reduce the overhead of
transfering data from a remote target to the local host. */
struct linux_info
{
/* Cache of the inferior's vsyscall/vDSO mapping range. Only valid
if VSYSCALL_RANGE_P is positive. This is cached because getting
at this info requires an auxv lookup (which is itself cached),
and looking through the inferior's mappings (which change
throughout execution and therefore cannot be cached). */
struct mem_range vsyscall_range {};
/* Zero if we haven't tried looking up the vsyscall's range before
yet. Positive if we tried looking it up, and found it. Negative
if we tried looking it up but failed. */
int vsyscall_range_p = 0;
/* Inferior's displaced step buffers. */
gdb::optional<displaced_step_buffers> disp_step_bufs;
};
/* Per-inferior data key. */
static const struct inferior_key<linux_info> linux_inferior_data;
/* Frees whatever allocated space there is to be freed and sets INF's
linux cache data pointer to NULL. */
static void
invalidate_linux_cache_inf (struct inferior *inf)
{
linux_inferior_data.clear (inf);
}
/* Fetch the linux cache info for INF. This function always returns a
valid INFO pointer. */
static struct linux_info *
get_linux_inferior_data (inferior *inf)
{
linux_info *info = linux_inferior_data.get (inf);
if (info == nullptr)
info = linux_inferior_data.emplace (inf);
return info;
}
/* See linux-tdep.h. */
struct type *
linux_get_siginfo_type_with_fields (struct gdbarch *gdbarch,
linux_siginfo_extra_fields extra_fields)
{
struct linux_gdbarch_data *linux_gdbarch_data;
struct type *int_type, *uint_type, *long_type, *void_ptr_type, *short_type;
struct type *uid_type, *pid_type;
struct type *sigval_type, *clock_type;
struct type *siginfo_type, *sifields_type;
struct type *type;
linux_gdbarch_data = get_linux_gdbarch_data (gdbarch);
if (linux_gdbarch_data->siginfo_type != NULL)
return linux_gdbarch_data->siginfo_type;
int_type = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch),
0, "int");
uint_type = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch),
1, "unsigned int");
long_type = arch_integer_type (gdbarch, gdbarch_long_bit (gdbarch),
0, "long");
short_type = arch_integer_type (gdbarch, gdbarch_long_bit (gdbarch),
0, "short");
void_ptr_type = lookup_pointer_type (builtin_type (gdbarch)->builtin_void);
/* sival_t */
sigval_type = arch_composite_type (gdbarch, NULL, TYPE_CODE_UNION);
sigval_type->set_name (xstrdup ("sigval_t"));
append_composite_type_field (sigval_type, "sival_int", int_type);
append_composite_type_field (sigval_type, "sival_ptr", void_ptr_type);
/* __pid_t */
pid_type = arch_type (gdbarch, TYPE_CODE_TYPEDEF,
TYPE_LENGTH (int_type) * TARGET_CHAR_BIT, "__pid_t");
TYPE_TARGET_TYPE (pid_type) = int_type;
pid_type->set_target_is_stub (true);
/* __uid_t */
uid_type = arch_type (gdbarch, TYPE_CODE_TYPEDEF,
TYPE_LENGTH (uint_type) * TARGET_CHAR_BIT, "__uid_t");
TYPE_TARGET_TYPE (uid_type) = uint_type;
uid_type->set_target_is_stub (true);
/* __clock_t */
clock_type = arch_type (gdbarch, TYPE_CODE_TYPEDEF,
TYPE_LENGTH (long_type) * TARGET_CHAR_BIT,
"__clock_t");
TYPE_TARGET_TYPE (clock_type) = long_type;
clock_type->set_target_is_stub (true);
/* _sifields */
sifields_type = arch_composite_type (gdbarch, NULL, TYPE_CODE_UNION);
{
const int si_max_size = 128;
int si_pad_size;
int size_of_int = gdbarch_int_bit (gdbarch) / HOST_CHAR_BIT;
/* _pad */
if (gdbarch_ptr_bit (gdbarch) == 64)
si_pad_size = (si_max_size / size_of_int) - 4;
else
si_pad_size = (si_max_size / size_of_int) - 3;
append_composite_type_field (sifields_type, "_pad",
init_vector_type (int_type, si_pad_size));
}
/* _kill */
type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
append_composite_type_field (type, "si_pid", pid_type);
append_composite_type_field (type, "si_uid", uid_type);
append_composite_type_field (sifields_type, "_kill", type);
/* _timer */
type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
append_composite_type_field (type, "si_tid", int_type);
append_composite_type_field (type, "si_overrun", int_type);
append_composite_type_field (type, "si_sigval", sigval_type);
append_composite_type_field (sifields_type, "_timer", type);
/* _rt */
type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
append_composite_type_field (type, "si_pid", pid_type);
append_composite_type_field (type, "si_uid", uid_type);
append_composite_type_field (type, "si_sigval", sigval_type);
append_composite_type_field (sifields_type, "_rt", type);
/* _sigchld */
type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
append_composite_type_field (type, "si_pid", pid_type);
append_composite_type_field (type, "si_uid", uid_type);
append_composite_type_field (type, "si_status", int_type);
append_composite_type_field (type, "si_utime", clock_type);
append_composite_type_field (type, "si_stime", clock_type);
append_composite_type_field (sifields_type, "_sigchld", type);
/* _sigfault */
type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
append_composite_type_field (type, "si_addr", void_ptr_type);
/* Additional bound fields for _sigfault in case they were requested. */
if ((extra_fields & LINUX_SIGINFO_FIELD_ADDR_BND) != 0)
{
struct type *sigfault_bnd_fields;
append_composite_type_field (type, "_addr_lsb", short_type);
sigfault_bnd_fields = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
append_composite_type_field (sigfault_bnd_fields, "_lower", void_ptr_type);
append_composite_type_field (sigfault_bnd_fields, "_upper", void_ptr_type);
append_composite_type_field (type, "_addr_bnd", sigfault_bnd_fields);
}
append_composite_type_field (sifields_type, "_sigfault", type);
/* _sigpoll */
type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
append_composite_type_field (type, "si_band", long_type);
append_composite_type_field (type, "si_fd", int_type);
append_composite_type_field (sifields_type, "_sigpoll", type);
/* _sigsys */
type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
append_composite_type_field (type, "_call_addr", void_ptr_type);
append_composite_type_field (type, "_syscall", int_type);
append_composite_type_field (type, "_arch", uint_type);
append_composite_type_field (sifields_type, "_sigsys", type);
/* struct siginfo */
siginfo_type = arch_composite_type (gdbarch, NULL, TYPE_CODE_STRUCT);
siginfo_type->set_name (xstrdup ("siginfo"));
append_composite_type_field (siginfo_type, "si_signo", int_type);
append_composite_type_field (siginfo_type, "si_errno", int_type);
append_composite_type_field (siginfo_type, "si_code", int_type);
append_composite_type_field_aligned (siginfo_type,
"_sifields", sifields_type,
TYPE_LENGTH (long_type));
linux_gdbarch_data->siginfo_type = siginfo_type;
return siginfo_type;
}
/* This function is suitable for architectures that don't
extend/override the standard siginfo structure. */
static struct type *
linux_get_siginfo_type (struct gdbarch *gdbarch)
{
return linux_get_siginfo_type_with_fields (gdbarch, 0);
}
/* Return true if the target is running on uClinux instead of normal
Linux kernel. */
int
linux_is_uclinux (void)
{
CORE_ADDR dummy;
target_ops *target = current_inferior ()->top_target ();
return (target_auxv_search (target, AT_NULL, &dummy) > 0
&& target_auxv_search (target, AT_PAGESZ, &dummy) == 0);
}
static int
linux_has_shared_address_space (struct gdbarch *gdbarch)
{
return linux_is_uclinux ();
}
/* This is how we want PTIDs from core files to be printed. */
static std::string
linux_core_pid_to_str (struct gdbarch *gdbarch, ptid_t ptid)
{
if (ptid.lwp () != 0)
return string_printf ("LWP %ld", ptid.lwp ());
return normal_pid_to_str (ptid);
}
/* Service function for corefiles and info proc. */
static void
read_mapping (const char *line,
ULONGEST *addr, ULONGEST *endaddr,
const char **permissions, size_t *permissions_len,
ULONGEST *offset,
const char **device, size_t *device_len,
ULONGEST *inode,
const char **filename)
{
const char *p = line;
*addr = strtoulst (p, &p, 16);
if (*p == '-')
p++;
*endaddr = strtoulst (p, &p, 16);
p = skip_spaces (p);
*permissions = p;
while (*p && !isspace (*p))
p++;
*permissions_len = p - *permissions;
*offset = strtoulst (p, &p, 16);
p = skip_spaces (p);
*device = p;
while (*p && !isspace (*p))
p++;
*device_len = p - *device;
*inode = strtoulst (p, &p, 10);
p = skip_spaces (p);
*filename = p;
}
/* Helper function to decode the "VmFlags" field in /proc/PID/smaps.
This function was based on the documentation found on
<Documentation/filesystems/proc.txt>, on the Linux kernel.
Linux kernels before commit
834f82e2aa9a8ede94b17b656329f850c1471514 (3.10) do not have this
field on smaps. */
static void
decode_vmflags (char *p, struct smaps_vmflags *v)
{
char *saveptr = NULL;
const char *s;
v->initialized_p = 1;
p = skip_to_space (p);
p = skip_spaces (p);
for (s = strtok_r (p, " ", &saveptr);
s != NULL;
s = strtok_r (NULL, " ", &saveptr))
{
if (strcmp (s, "io") == 0)
v->io_page = 1;
else if (strcmp (s, "ht") == 0)
v->uses_huge_tlb = 1;
else if (strcmp (s, "dd") == 0)
v->exclude_coredump = 1;
else if (strcmp (s, "sh") == 0)
v->shared_mapping = 1;
else if (strcmp (s, "mt") == 0)
v->memory_tagging = 1;
}
}
/* Regexes used by mapping_is_anonymous_p. Put in a structure because
they're initialized lazily. */
struct mapping_regexes
{
/* Matches "/dev/zero" filenames (with or without the "(deleted)"
string in the end). We know for sure, based on the Linux kernel
code, that memory mappings whose associated filename is
"/dev/zero" are guaranteed to be MAP_ANONYMOUS. */
compiled_regex dev_zero
{"^/dev/zero\\( (deleted)\\)\\?$", REG_NOSUB,
_("Could not compile regex to match /dev/zero filename")};
/* Matches "/SYSV%08x" filenames (with or without the "(deleted)"
string in the end). These filenames refer to shared memory
(shmem), and memory mappings associated with them are
MAP_ANONYMOUS as well. */
compiled_regex shmem_file
{"^/\\?SYSV[0-9a-fA-F]\\{8\\}\\( (deleted)\\)\\?$", REG_NOSUB,
_("Could not compile regex to match shmem filenames")};
/* A heuristic we use to try to mimic the Linux kernel's 'n_link ==
0' code, which is responsible to decide if it is dealing with a
'MAP_SHARED | MAP_ANONYMOUS' mapping. In other words, if
FILE_DELETED matches, it does not necessarily mean that we are
dealing with an anonymous shared mapping. However, there is no
easy way to detect this currently, so this is the best
approximation we have.
As a result, GDB will dump readonly pages of deleted executables
when using the default value of coredump_filter (0x33), while the
Linux kernel will not dump those pages. But we can live with
that. */
compiled_regex file_deleted
{" (deleted)$", REG_NOSUB,
_("Could not compile regex to match '<file> (deleted)'")};
};
/* Return 1 if the memory mapping is anonymous, 0 otherwise.
FILENAME is the name of the file present in the first line of the
memory mapping, in the "/proc/PID/smaps" output. For example, if
the first line is:
7fd0ca877000-7fd0d0da0000 r--p 00000000 fd:02 2100770 /path/to/file
Then FILENAME will be "/path/to/file". */
static int
mapping_is_anonymous_p (const char *filename)
{
static gdb::optional<mapping_regexes> regexes;
static int init_regex_p = 0;
if (!init_regex_p)
{
/* Let's be pessimistic and assume there will be an error while
compiling the regex'es. */
init_regex_p = -1;
regexes.emplace ();
/* If we reached this point, then everything succeeded. */
init_regex_p = 1;
}
if (init_regex_p == -1)
{
const char deleted[] = " (deleted)";
size_t del_len = sizeof (deleted) - 1;
size_t filename_len = strlen (filename);
/* There was an error while compiling the regex'es above. In
order to try to give some reliable information to the caller,
we just try to find the string " (deleted)" in the filename.
If we managed to find it, then we assume the mapping is
anonymous. */
return (filename_len >= del_len
&& strcmp (filename + filename_len - del_len, deleted) == 0);
}
if (*filename == '\0'
|| regexes->dev_zero.exec (filename, 0, NULL, 0) == 0
|| regexes->shmem_file.exec (filename, 0, NULL, 0) == 0
|| regexes->file_deleted.exec (filename, 0, NULL, 0) == 0)
return 1;
return 0;
}
/* Return 0 if the memory mapping (which is related to FILTERFLAGS, V,
MAYBE_PRIVATE_P, MAPPING_ANONYMOUS_P, ADDR and OFFSET) should not
be dumped, or greater than 0 if it should.
In a nutshell, this is the logic that we follow in order to decide
if a mapping should be dumped or not.
- If the mapping is associated to a file whose name ends with
" (deleted)", or if the file is "/dev/zero", or if it is
"/SYSV%08x" (shared memory), or if there is no file associated
with it, or if the AnonHugePages: or the Anonymous: fields in the
/proc/PID/smaps have contents, then GDB considers this mapping to
be anonymous. Otherwise, GDB considers this mapping to be a
file-backed mapping (because there will be a file associated with
it).
It is worth mentioning that, from all those checks described
above, the most fragile is the one to see if the file name ends
with " (deleted)". This does not necessarily mean that the
mapping is anonymous, because the deleted file associated with
the mapping may have been a hard link to another file, for
example. The Linux kernel checks to see if "i_nlink == 0", but
GDB cannot easily (and normally) do this check (iff running as
root, it could find the mapping in /proc/PID/map_files/ and
determine whether there still are other hard links to the
inode/file). Therefore, we made a compromise here, and we assume
that if the file name ends with " (deleted)", then the mapping is
indeed anonymous. FWIW, this is something the Linux kernel could
do better: expose this information in a more direct way.
- If we see the flag "sh" in the "VmFlags:" field (in
/proc/PID/smaps), then certainly the memory mapping is shared
(VM_SHARED). If we have access to the VmFlags, and we don't see
the "sh" there, then certainly the mapping is private. However,
Linux kernels before commit
834f82e2aa9a8ede94b17b656329f850c1471514 (3.10) do not have the
"VmFlags:" field; in that case, we use another heuristic: if we
see 'p' in the permission flags, then we assume that the mapping
is private, even though the presence of the 's' flag there would
mean VM_MAYSHARE, which means the mapping could still be private.
This should work OK enough, however.
- Even if, at the end, we decided that we should not dump the
mapping, we still have to check if it is something like an ELF
header (of a DSO or an executable, for example). If it is, and
if the user is interested in dump it, then we should dump it. */
static int
dump_mapping_p (filter_flags filterflags, const struct smaps_vmflags *v,
int maybe_private_p, int mapping_anon_p, int mapping_file_p,
const char *filename, ULONGEST addr, ULONGEST offset)
{
/* Initially, we trust in what we received from our caller. This
value may not be very precise (i.e., it was probably gathered
from the permission line in the /proc/PID/smaps list, which
actually refers to VM_MAYSHARE, and not VM_SHARED), but it is
what we have until we take a look at the "VmFlags:" field
(assuming that the version of the Linux kernel being used
supports it, of course). */
int private_p = maybe_private_p;
int dump_p;
/* We always dump vDSO and vsyscall mappings, because it's likely that
there'll be no file to read the contents from at core load time.
The kernel does the same. */
if (strcmp ("[vdso]", filename) == 0
|| strcmp ("[vsyscall]", filename) == 0)
return 1;
if (v->initialized_p)
{
/* We never dump I/O mappings. */
if (v->io_page)
return 0;
/* Check if we should exclude this mapping. */
if (!dump_excluded_mappings && v->exclude_coredump)
return 0;
/* Update our notion of whether this mapping is shared or
private based on a trustworthy value. */
private_p = !v->shared_mapping;
/* HugeTLB checking. */
if (v->uses_huge_tlb)
{
if ((private_p && (filterflags & COREFILTER_HUGETLB_PRIVATE))
|| (!private_p && (filterflags & COREFILTER_HUGETLB_SHARED)))
return 1;
return 0;
}
}
if (private_p)
{
if (mapping_anon_p && mapping_file_p)
{
/* This is a special situation. It can happen when we see a
mapping that is file-backed, but that contains anonymous
pages. */
dump_p = ((filterflags & COREFILTER_ANON_PRIVATE) != 0
|| (filterflags & COREFILTER_MAPPED_PRIVATE) != 0);
}
else if (mapping_anon_p)
dump_p = (filterflags & COREFILTER_ANON_PRIVATE) != 0;
else
dump_p = (filterflags & COREFILTER_MAPPED_PRIVATE) != 0;
}
else
{
if (mapping_anon_p && mapping_file_p)
{
/* This is a special situation. It can happen when we see a
mapping that is file-backed, but that contains anonymous
pages. */
dump_p = ((filterflags & COREFILTER_ANON_SHARED) != 0
|| (filterflags & COREFILTER_MAPPED_SHARED) != 0);
}
else if (mapping_anon_p)
dump_p = (filterflags & COREFILTER_ANON_SHARED) != 0;
else
dump_p = (filterflags & COREFILTER_MAPPED_SHARED) != 0;
}
/* Even if we decided that we shouldn't dump this mapping, we still
have to check whether (a) the user wants us to dump mappings
containing an ELF header, and (b) the mapping in question
contains an ELF header. If (a) and (b) are true, then we should
dump this mapping.
A mapping contains an ELF header if it is a private mapping, its
offset is zero, and its first word is ELFMAG. */
if (!dump_p && private_p && offset == 0
&& (filterflags & COREFILTER_ELF_HEADERS) != 0)
{
/* Useful define specifying the size of the ELF magical
header. */
#ifndef SELFMAG
#define SELFMAG 4
#endif
/* Let's check if we have an ELF header. */
gdb_byte h[SELFMAG];
if (target_read_memory (addr, h, SELFMAG) == 0)
{
/* The EI_MAG* and ELFMAG* constants come from
<elf/common.h>. */
if (h[EI_MAG0] == ELFMAG0 && h[EI_MAG1] == ELFMAG1
&& h[EI_MAG2] == ELFMAG2 && h[EI_MAG3] == ELFMAG3)
{
/* This mapping contains an ELF header, so we
should dump it. */
dump_p = 1;
}
}
}
return dump_p;
}
/* As above, but return true only when we should dump the NT_FILE
entry. */
static int
dump_note_entry_p (filter_flags filterflags, const struct smaps_vmflags *v,
int maybe_private_p, int mapping_anon_p, int mapping_file_p,
const char *filename, ULONGEST addr, ULONGEST offset)
{
/* vDSO and vsyscall mappings will end up in the core file. Don't
put them in the NT_FILE note. */
if (strcmp ("[vdso]", filename) == 0
|| strcmp ("[vsyscall]", filename) == 0)
return 0;
/* Otherwise, any other file-based mapping should be placed in the
note. */
return 1;
}
/* Implement the "info proc" command. */
static void
linux_info_proc (struct gdbarch *gdbarch, const char *args,
enum info_proc_what what)
{
/* A long is used for pid instead of an int to avoid a loss of precision
compiler warning from the output of strtoul. */
long pid;
int cmdline_f = (what == IP_MINIMAL || what == IP_CMDLINE || what == IP_ALL);
int cwd_f = (what == IP_MINIMAL || what == IP_CWD || what == IP_ALL);
int exe_f = (what == IP_MINIMAL || what == IP_EXE || what == IP_ALL);
int mappings_f = (what == IP_MAPPINGS || what == IP_ALL);
int status_f = (what == IP_STATUS || what == IP_ALL);
int stat_f = (what == IP_STAT || what == IP_ALL);
char filename[100];
int target_errno;
if (args && isdigit (args[0]))
{
char *tem;
pid = strtoul (args, &tem, 10);
args = tem;
}
else
{
if (!target_has_execution ())
error (_("No current process: you must name one."));
if (current_inferior ()->fake_pid_p)
error (_("Can't determine the current process's PID: you must name one."));
pid = current_inferior ()->pid;
}
args = skip_spaces (args);
if (args && args[0])
error (_("Too many parameters: %s"), args);
printf_filtered (_("process %ld\n"), pid);
if (cmdline_f)
{
xsnprintf (filename, sizeof filename, "/proc/%ld/cmdline", pid);
gdb_byte *buffer;
ssize_t len = target_fileio_read_alloc (NULL, filename, &buffer);
if (len > 0)
{
gdb::unique_xmalloc_ptr<char> cmdline ((char *) buffer);
ssize_t pos;
for (pos = 0; pos < len - 1; pos++)
{
if (buffer[pos] == '\0')
buffer[pos] = ' ';
}
buffer[len - 1] = '\0';
printf_filtered ("cmdline = '%s'\n", buffer);
}
else
warning (_("unable to open /proc file '%s'"), filename);
}
if (cwd_f)
{
xsnprintf (filename, sizeof filename, "/proc/%ld/cwd", pid);
gdb::optional<std::string> contents
= target_fileio_readlink (NULL, filename, &target_errno);
if (contents.has_value ())
printf_filtered ("cwd = '%s'\n", contents->c_str ());
else
warning (_("unable to read link '%s'"), filename);
}
if (exe_f)
{
xsnprintf (filename, sizeof filename, "/proc/%ld/exe", pid);
gdb::optional<std::string> contents
= target_fileio_readlink (NULL, filename, &target_errno);
if (contents.has_value ())
printf_filtered ("exe = '%s'\n", contents->c_str ());
else
warning (_("unable to read link '%s'"), filename);
}
if (mappings_f)
{
xsnprintf (filename, sizeof filename, "/proc/%ld/maps", pid);
gdb::unique_xmalloc_ptr<char> map
= target_fileio_read_stralloc (NULL, filename);
if (map != NULL)
{
char *line;
printf_filtered (_("Mapped address spaces:\n\n"));
if (gdbarch_addr_bit (gdbarch) == 32)
{
printf_filtered ("\t%10s %10s %10s %10s %s\n",
"Start Addr",
" End Addr",
" Size", " Offset", "objfile");
}
else
{
printf_filtered (" %18s %18s %10s %10s %s\n",
"Start Addr",
" End Addr",
" Size", " Offset", "objfile");
}
char *saveptr;
for (line = strtok_r (map.get (), "\n", &saveptr);
line;
line = strtok_r (NULL, "\n", &saveptr))
{
ULONGEST addr, endaddr, offset, inode;
const char *permissions, *device, *mapping_filename;
size_t permissions_len, device_len;
read_mapping (line, &addr, &endaddr,
&permissions, &permissions_len,
&offset, &device, &device_len,
&inode, &mapping_filename);
if (gdbarch_addr_bit (gdbarch) == 32)
{
printf_filtered ("\t%10s %10s %10s %10s %s\n",
paddress (gdbarch, addr),
paddress (gdbarch, endaddr),
hex_string (endaddr - addr),
hex_string (offset),
*mapping_filename ? mapping_filename : "");
}
else
{
printf_filtered (" %18s %18s %10s %10s %s\n",
paddress (gdbarch, addr),
paddress (gdbarch, endaddr),
hex_string (endaddr - addr),
hex_string (offset),
*mapping_filename ? mapping_filename : "");
}
}
}
else
warning (_("unable to open /proc file '%s'"), filename);
}
if (status_f)
{
xsnprintf (filename, sizeof filename, "/proc/%ld/status", pid);
gdb::unique_xmalloc_ptr<char> status
= target_fileio_read_stralloc (NULL, filename);
if (status)
puts_filtered (status.get ());
else
warning (_("unable to open /proc file '%s'"), filename);
}
if (stat_f)
{
xsnprintf (filename, sizeof filename, "/proc/%ld/stat", pid);
gdb::unique_xmalloc_ptr<char> statstr
= target_fileio_read_stralloc (NULL, filename);
if (statstr)
{
const char *p = statstr.get ();
printf_filtered (_("Process: %s\n"),
pulongest (strtoulst (p, &p, 10)));
p = skip_spaces (p);
if (*p == '(')
{
/* ps command also relies on no trailing fields
ever contain ')'. */
const char *ep = strrchr (p, ')');
if (ep != NULL)
{
printf_filtered ("Exec file: %.*s\n",
(int) (ep - p - 1), p + 1);
p = ep + 1;
}
}
p = skip_spaces (p);
if (*p)
printf_filtered (_("State: %c\n"), *p++);
if (*p)
printf_filtered (_("Parent process: %s\n"),
pulongest (strtoulst (p, &p, 10)));
if (*p)
printf_filtered (_("Process group: %s\n"),
pulongest (strtoulst (p, &p, 10)));
if (*p)
printf_filtered (_("Session id: %s\n"),
pulongest (strtoulst (p, &p, 10)));
if (*p)
printf_filtered (_("TTY: %s\n"),
pulongest (strtoulst (p, &p, 10)));
if (*p)
printf_filtered (_("TTY owner process group: %s\n"),
pulongest (strtoulst (p, &p, 10)));
if (*p)
printf_filtered (_("Flags: %s\n"),
hex_string (strtoulst (p, &p, 10)));
if (*p)
printf_filtered (_("Minor faults (no memory page): %s\n"),
pulongest (strtoulst (p, &p, 10)));
if (*p)
printf_filtered (_("Minor faults, children: %s\n"),
pulongest (strtoulst (p, &p, 10)));
if (*p)
printf_filtered (_("Major faults (memory page faults): %s\n"),
pulongest (strtoulst (p, &p, 10)));
if (*p)