gdb/nto-tdep.c

/* nto-tdep.c - general QNX Neutrino target functionality.

   Copyright (C) 2003-2021 Free Software Foundation, Inc.

   Contributed by QNX Software Systems Ltd.

   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 <sys/stat.h>
#include "nto-tdep.h"
#include "top.h"
#include "inferior.h"
#include "infrun.h"
#include "gdbarch.h"
#include "bfd.h"
#include "elf-bfd.h"
#include "solib-svr4.h"
#include "gdbcore.h"
#include "objfiles.h"
#include "source.h"
#include "gdbsupport/pathstuff.h"

#define QNX_NOTE_NAME	"QNX"
#define QNX_INFO_SECT_NAME "QNX_info"

#ifdef __CYGWIN__
#include <sys/cygwin.h>
#endif

#ifdef __CYGWIN__
static char default_nto_target[] = "C:\\QNXsdk\\target\\qnx6";
#elif defined(__sun__) || defined(linux)
static char default_nto_target[] = "/opt/QNXsdk/target/qnx6";
#else
static char default_nto_target[] = "";
#endif

struct nto_target_ops current_nto_target;

static const struct inferior_key<struct nto_inferior_data>
  nto_inferior_data_reg;

static char *
nto_target (void)
{
  char *p = getenv ("QNX_TARGET");

#ifdef __CYGWIN__
  static char buf[PATH_MAX];
  if (p)
    cygwin_conv_path (CCP_WIN_A_TO_POSIX, p, buf, PATH_MAX);
  else
    cygwin_conv_path (CCP_WIN_A_TO_POSIX, default_nto_target, buf, PATH_MAX);
  return buf;
#else
  return p ? p : default_nto_target;
#endif
}

/* Take a string such as i386, rs6000, etc. and map it onto CPUTYPE_X86,
   CPUTYPE_PPC, etc. as defined in nto-share/dsmsgs.h.  */
int
nto_map_arch_to_cputype (const char *arch)
{
  if (!strcmp (arch, "i386") || !strcmp (arch, "x86"))
    return CPUTYPE_X86;
  if (!strcmp (arch, "rs6000") || !strcmp (arch, "powerpc"))
    return CPUTYPE_PPC;
  if (!strcmp (arch, "mips"))
    return CPUTYPE_MIPS;
  if (!strcmp (arch, "arm"))
    return CPUTYPE_ARM;
  if (!strcmp (arch, "sh"))
    return CPUTYPE_SH;
  return CPUTYPE_UNKNOWN;
}

int
nto_find_and_open_solib (const char *solib, unsigned o_flags,
			 gdb::unique_xmalloc_ptr<char> *temp_pathname)
{
  char *buf, *arch_path, *nto_root;
  const char *endian;
  const char *base;
  const char *arch;
  int arch_len, len, ret;
#define PATH_FMT \
  "%s/lib:%s/usr/lib:%s/usr/photon/lib:%s/usr/photon/dll:%s/lib/dll"

  nto_root = nto_target ();
  if (strcmp (gdbarch_bfd_arch_info (target_gdbarch ())->arch_name, "i386") == 0)
    {
      arch = "x86";
      endian = "";
    }
  else if (strcmp (gdbarch_bfd_arch_info (target_gdbarch ())->arch_name,
		   "rs6000") == 0
	   || strcmp (gdbarch_bfd_arch_info (target_gdbarch ())->arch_name,
		   "powerpc") == 0)
    {
      arch = "ppc";
      endian = "be";
    }
  else
    {
      arch = gdbarch_bfd_arch_info (target_gdbarch ())->arch_name;
      endian = gdbarch_byte_order (target_gdbarch ())
	       == BFD_ENDIAN_BIG ? "be" : "le";
    }

  /* In case nto_root is short, add strlen(solib)
     so we can reuse arch_path below.  */

  arch_len = (strlen (nto_root) + strlen (arch) + strlen (endian) + 2
	      + strlen (solib));
  arch_path = (char *) alloca (arch_len);
  xsnprintf (arch_path, arch_len, "%s/%s%s", nto_root, arch, endian);

  len = strlen (PATH_FMT) + strlen (arch_path) * 5 + 1;
  buf = (char *) alloca (len);
  xsnprintf (buf, len, PATH_FMT, arch_path, arch_path, arch_path, arch_path,
	     arch_path);

  base = lbasename (solib);
  ret = openp (buf, OPF_TRY_CWD_FIRST | OPF_RETURN_REALPATH, base, o_flags,
	       temp_pathname);
  if (ret < 0 && base != solib)
    {
      xsnprintf (arch_path, arch_len, "/%s", solib);
      ret = open (arch_path, o_flags, 0);
      if (temp_pathname)
	{
	  if (ret >= 0)
	    *temp_pathname = gdb_realpath (arch_path);
	  else
	    temp_pathname->reset (NULL);
	}
    }
  return ret;
}

void
nto_init_solib_absolute_prefix (void)
{
  char buf[PATH_MAX * 2], arch_path[PATH_MAX];
  char *nto_root;
  const char *endian;
  const char *arch;

  nto_root = nto_target ();
  if (strcmp (gdbarch_bfd_arch_info (target_gdbarch ())->arch_name, "i386") == 0)
    {
      arch = "x86";
      endian = "";
    }
  else if (strcmp (gdbarch_bfd_arch_info (target_gdbarch ())->arch_name,
		   "rs6000") == 0
	   || strcmp (gdbarch_bfd_arch_info (target_gdbarch ())->arch_name,
		   "powerpc") == 0)
    {
      arch = "ppc";
      endian = "be";
    }
  else
    {
      arch = gdbarch_bfd_arch_info (target_gdbarch ())->arch_name;
      endian = gdbarch_byte_order (target_gdbarch ())
	       == BFD_ENDIAN_BIG ? "be" : "le";
    }

  xsnprintf (arch_path, sizeof (arch_path), "%s/%s%s", nto_root, arch, endian);

  xsnprintf (buf, sizeof (buf), "set solib-absolute-prefix %s", arch_path);
  execute_command (buf, 0);
}

char **
nto_parse_redirection (char *pargv[], const char **pin, const char **pout, 
		       const char **perr)
{
  char **argv;
  const char *in, *out, *err, *p;
  int argc, i, n;

  for (n = 0; pargv[n]; n++);
  if (n == 0)
    return NULL;
  in = "";
  out = "";
  err = "";

  argv = XCNEWVEC (char *, n + 1);
  argc = n;
  for (i = 0, n = 0; n < argc; n++)
    {
      p = pargv[n];
      if (*p == '>')
	{
	  p++;
	  if (*p)
	    out = p;
	  else
	    out = pargv[++n];
	}
      else if (*p == '<')
	{
	  p++;
	  if (*p)
	    in = p;
	  else
	    in = pargv[++n];
	}
      else if (*p++ == '2' && *p++ == '>')
	{
	  if (*p == '&' && *(p + 1) == '1')
	    err = out;
	  else if (*p)
	    err = p;
	  else
	    err = pargv[++n];
	}
      else
	argv[i++] = pargv[n];
    }
  *pin = in;
  *pout = out;
  *perr = err;
  return argv;
}

static CORE_ADDR
lm_addr (struct so_list *so)
{
  lm_info_svr4 *li = (lm_info_svr4 *) so->lm_info;

  return li->l_addr;
}

static CORE_ADDR
nto_truncate_ptr (CORE_ADDR addr)
{
  if (gdbarch_ptr_bit (target_gdbarch ()) == sizeof (CORE_ADDR) * 8)
    /* We don't need to truncate anything, and the bit twiddling below
       will fail due to overflow problems.  */
    return addr;
  else
    return addr & (((CORE_ADDR) 1 << gdbarch_ptr_bit (target_gdbarch ())) - 1);
}

static Elf_Internal_Phdr *
find_load_phdr (bfd *abfd)
{
  Elf_Internal_Phdr *phdr;
  unsigned int i;

  if (!elf_tdata (abfd))
    return NULL;

  phdr = elf_tdata (abfd)->phdr;
  for (i = 0; i < elf_elfheader (abfd)->e_phnum; i++, phdr++)
    {
      if (phdr->p_type == PT_LOAD && (phdr->p_flags & PF_X))
	return phdr;
    }
  return NULL;
}

void
nto_relocate_section_addresses (struct so_list *so, struct target_section *sec)
{
  /* Neutrino treats the l_addr base address field in link.h as different than
     the base address in the System V ABI and so the offset needs to be
     calculated and applied to relocations.  */
  Elf_Internal_Phdr *phdr = find_load_phdr (sec->the_bfd_section->owner);
  unsigned vaddr = phdr ? phdr->p_vaddr : 0;

  sec->addr = nto_truncate_ptr (sec->addr + lm_addr (so) - vaddr);
  sec->endaddr = nto_truncate_ptr (sec->endaddr + lm_addr (so) - vaddr);
}

/* This is cheating a bit because our linker code is in libc.so.  If we
   ever implement lazy linking, this may need to be re-examined.  */
int
nto_in_dynsym_resolve_code (CORE_ADDR pc)
{
  if (in_plt_section (pc))
    return 1;
  return 0;
}

void
nto_dummy_supply_regset (struct regcache *regcache, char *regs)
{
  /* Do nothing.  */
}

static void
nto_sniff_abi_note_section (bfd *abfd, asection *sect, void *obj)
{
  const char *sectname;
  unsigned int sectsize;
  /* Buffer holding the section contents.  */
  char *note;
  unsigned int namelen;
  const char *name;
  const unsigned sizeof_Elf_Nhdr = 12;

  sectname = bfd_section_name (sect);
  sectsize = bfd_section_size (sect);

  if (sectsize > 128)
    sectsize = 128;

  if (sectname != NULL && strstr (sectname, QNX_INFO_SECT_NAME) != NULL)
    *(enum gdb_osabi *) obj = GDB_OSABI_QNXNTO;
  else if (sectname != NULL && strstr (sectname, "note") != NULL
	   && sectsize > sizeof_Elf_Nhdr)
    {
      note = XNEWVEC (char, sectsize);
      bfd_get_section_contents (abfd, sect, note, 0, sectsize);
      namelen = (unsigned int) bfd_h_get_32 (abfd, note);
      name = note + sizeof_Elf_Nhdr;
      if (sectsize >= namelen + sizeof_Elf_Nhdr
	  && namelen == sizeof (QNX_NOTE_NAME)
	  && 0 == strcmp (name, QNX_NOTE_NAME))
	*(enum gdb_osabi *) obj = GDB_OSABI_QNXNTO;

      XDELETEVEC (note);
    }
}

enum gdb_osabi
nto_elf_osabi_sniffer (bfd *abfd)
{
  enum gdb_osabi osabi = GDB_OSABI_UNKNOWN;

  bfd_map_over_sections (abfd,
			 nto_sniff_abi_note_section,
			 &osabi);

  return osabi;
}

static const char * const nto_thread_state_str[] =
{
  "DEAD",		/* 0  0x00 */
  "RUNNING",	/* 1  0x01 */
  "READY",	/* 2  0x02 */
  "STOPPED",	/* 3  0x03 */
  "SEND",		/* 4  0x04 */
  "RECEIVE",	/* 5  0x05 */
  "REPLY",	/* 6  0x06 */
  "STACK",	/* 7  0x07 */
  "WAITTHREAD",	/* 8  0x08 */
  "WAITPAGE",	/* 9  0x09 */
  "SIGSUSPEND",	/* 10 0x0a */
  "SIGWAITINFO",	/* 11 0x0b */
  "NANOSLEEP",	/* 12 0x0c */
  "MUTEX",	/* 13 0x0d */
  "CONDVAR",	/* 14 0x0e */
  "JOIN",		/* 15 0x0f */
  "INTR",		/* 16 0x10 */
  "SEM",		/* 17 0x11 */
  "WAITCTX",	/* 18 0x12 */
  "NET_SEND",	/* 19 0x13 */
  "NET_REPLY"	/* 20 0x14 */
};

const char *
nto_extra_thread_info (struct target_ops *self, struct thread_info *ti)
{
  if (ti != NULL && ti->priv != NULL)
    {
      nto_thread_info *priv = get_nto_thread_info (ti);

      if (priv->state < ARRAY_SIZE (nto_thread_state_str))
	return nto_thread_state_str [priv->state];
    }
  return "";
}

void
nto_initialize_signals (void)
{
  /* We use SIG45 for pulses, or something, so nostop, noprint
     and pass them.  */
  signal_stop_update (gdb_signal_from_name ("SIG45"), 0);
  signal_print_update (gdb_signal_from_name ("SIG45"), 0);
  signal_pass_update (gdb_signal_from_name ("SIG45"), 1);

  /* By default we don't want to stop on these two, but we do want to pass.  */
#if defined(SIGSELECT)
  signal_stop_update (SIGSELECT, 0);
  signal_print_update (SIGSELECT, 0);
  signal_pass_update (SIGSELECT, 1);
#endif

#if defined(SIGPHOTON)
  signal_stop_update (SIGPHOTON, 0);
  signal_print_update (SIGPHOTON, 0);
  signal_pass_update (SIGPHOTON, 1);
#endif
}

/* Read AUXV from initial_stack.  */
LONGEST
nto_read_auxv_from_initial_stack (CORE_ADDR initial_stack, gdb_byte *readbuf,
				  LONGEST len, size_t sizeof_auxv_t)
{
  gdb_byte targ32[4]; /* For 32 bit target values.  */
  gdb_byte targ64[8]; /* For 64 bit target values.  */
  CORE_ADDR data_ofs = 0;
  ULONGEST anint;
  LONGEST len_read = 0;
  gdb_byte *buff;
  enum bfd_endian byte_order;
  int ptr_size;

  if (sizeof_auxv_t == 16)
    ptr_size = 8;
  else
    ptr_size = 4;

  /* Skip over argc, argv and envp... Comment from ldd.c:

     The startup frame is set-up so that we have:
     auxv
     NULL
     ...
     envp2
     envp1 <----- void *frame + (argc + 2) * sizeof(char *)
     NULL
     ...
     argv2
     argv1
     argc  <------ void * frame

     On entry to ldd, frame gives the address of argc on the stack.  */
  /* Read argc. 4 bytes on both 64 and 32 bit arches and luckily little
   * endian. So we just read first 4 bytes.  */
  if (target_read_memory (initial_stack + data_ofs, targ32, 4) != 0)
    return 0;

  byte_order = gdbarch_byte_order (target_gdbarch ());

  anint = extract_unsigned_integer (targ32, sizeof (targ32), byte_order);

  /* Size of pointer is assumed to be 4 bytes (32 bit arch.) */
  data_ofs += (anint + 2) * ptr_size; /* + 2 comes from argc itself and
						NULL terminating pointer in
						argv.  */

  /* Now loop over env table:  */
  anint = 0;
  while (target_read_memory (initial_stack + data_ofs, targ64, ptr_size)
	 == 0)
    {
      if (extract_unsigned_integer (targ64, ptr_size, byte_order) == 0)
	anint = 1; /* Keep looping until non-null entry is found.  */
      else if (anint)
	break;
      data_ofs += ptr_size;
    }
  initial_stack += data_ofs;

  memset (readbuf, 0, len);
  buff = readbuf;
  while (len_read <= len-sizeof_auxv_t)
    {
      if (target_read_memory (initial_stack + len_read, buff, sizeof_auxv_t)
	  == 0)
	{
	  /* Both 32 and 64 bit structures have int as the first field.  */
	  const ULONGEST a_type
	    = extract_unsigned_integer (buff, sizeof (targ32), byte_order);

	  if (a_type == AT_NULL)
	    break;
	  buff += sizeof_auxv_t;
	  len_read += sizeof_auxv_t;
	}
      else
	break;
    }
  return len_read;
}

/* Return nto_inferior_data for the given INFERIOR.  If not yet created,
   construct it.  */

struct nto_inferior_data *
nto_inferior_data (struct inferior *const inferior)
{
  struct inferior *const inf = inferior ? inferior : current_inferior ();
  struct nto_inferior_data *inf_data;

  gdb_assert (inf != NULL);

  inf_data = nto_inferior_data_reg.get (inf);
  if (inf_data == NULL)
    inf_data = nto_inferior_data_reg.emplace (inf);

  return inf_data;
}