Merge gdb and gdbserver implementations for siginfo

Extract the compatible siginfo handling from amd64-linux-nat.c and
gdbserver/linux-x86-low to a new file nat/amd64-linux-siginfo.c.

2016-02-02  Walfred Tedeschi  <walfred.tedeschi@intel.com>

gdb/ChangeLog:

	* nat/amd64-linux-siginfo.c: New file.
	* nat/amd64-linux-siginfo.h: New file.
	* Makefile.in (HFILES_NO_SRCDIR): Add nat/amd64-linux-siginfo.h.
	(amd64-linux-siginfo.o): New rule.
	* config/i386/linux64.mh (NATDEPFILES): Add amd64-linux-siginfo.o.
	* amd64-linux-nat.c (nat/amd64-linux-siginfo.h): New include.
	(compat_siginfo_from_siginfo, siginfo_from_compat_siginfo)
	(compat_x32_siginfo_from_siginfo, siginfo_from_compat_x32_siginfo)
	(compat_timeval, compat_sigval, compat_x32_clock, cpt_si_pid)
	(cpt_si_uid, cpt_si_timerid, cpt_si_overrun, cpt_si_status)
	(cpt_si_utime, cpt_si_stime, cpt_si_ptr, cpt_si_addr, cpt_si_band)
	(cpt_si_fd, si_timerid, si_overrun): Move to nat/amd64-linux-siginfo.c.

gdb/gdbserver/ChangeLog:

	* configure.srv (x86_64-*-linux*): Add amd64-linux-siginfo.o
	to srv_tgtobj.
	(i[34567]86-*-linux*): Add amd64-linux-siginfo.o
	to srv_tgtobj.
	* linux-x86-low.c [__x86_64__]: Include
	"nat/amd64-linux-siginfo.h".
	(compat_siginfo_from_siginfo, siginfo_from_compat_siginfo)
	(compat_x32_siginfo_from_siginfo, siginfo_from_compat_x32_siginfo)
	(compat_timeval, compat_sigval, compat_x32_clock, cpt_si_pid)
	(cpt_si_uid, cpt_si_timerid, cpt_si_overrun, cpt_si_status)
	(cpt_si_utime, cpt_si_stime, cpt_si_ptr, cpt_si_addr, cpt_si_band)
	(cpt_si_fd, si_timerid, si_overrun): Move from
	nat/amd64-linux-siginfo.c.
	* Makefile.in (amd64-linux-siginfo.o:): New rule.

2 files changed, 506 insertions, 0 deletions

diff --git a/gdb/nat/amd64-linux-siginfo.c b/gdb/nat/amd64-linux-siginfo.c
new file mode 100644
index 0000000..36b5505
--- /dev/null
+++ b/gdb/nat/amd64-linux-siginfo.c
@@ -0,0 +1,462 @@
+/* Low-level siginfo manipulation for amd64.
+
+   Copyright (C) 2002-2016 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 <signal.h>
+#include "common-defs.h"
+#include "amd64-linux-siginfo.h"
+
+/* These types below (compat_*) define a siginfo type that is layout
+   compatible with the siginfo type exported by the 32-bit userspace
+   support.  */
+
+typedef int compat_int_t;
+typedef unsigned int compat_uptr_t;
+
+typedef int compat_time_t;
+typedef int compat_timer_t;
+typedef int compat_clock_t;
+
+struct compat_timeval
+{
+  compat_time_t tv_sec;
+  int tv_usec;
+};
+
+typedef union compat_sigval
+{
+  compat_int_t sival_int;
+  compat_uptr_t sival_ptr;
+} compat_sigval_t;
+
+typedef struct compat_siginfo
+{
+  int si_signo;
+  int si_errno;
+  int si_code;
+
+  union
+  {
+    int _pad[((128 / sizeof (int)) - 3)];
+
+    /* kill() */
+    struct
+    {
+      unsigned int _pid;
+      unsigned int _uid;
+    } _kill;
+
+    /* POSIX.1b timers */
+    struct
+    {
+      compat_timer_t _tid;
+      int _overrun;
+      compat_sigval_t _sigval;
+    } _timer;
+
+    /* POSIX.1b signals */
+    struct
+    {
+      unsigned int _pid;
+      unsigned int _uid;
+      compat_sigval_t _sigval;
+    } _rt;
+
+    /* SIGCHLD */
+    struct
+    {
+      unsigned int _pid;
+      unsigned int _uid;
+      int _status;
+      compat_clock_t _utime;
+      compat_clock_t _stime;
+    } _sigchld;
+
+    /* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
+    struct
+    {
+      unsigned int _addr;
+    } _sigfault;
+
+    /* SIGPOLL */
+    struct
+    {
+      int _band;
+      int _fd;
+    } _sigpoll;
+  } _sifields;
+} compat_siginfo_t;
+
+/* For x32, clock_t in _sigchld is 64bit aligned at 4 bytes.  */
+typedef long __attribute__ ((__aligned__ (4))) compat_x32_clock_t;
+
+typedef struct compat_x32_siginfo
+{
+  int si_signo;
+  int si_errno;
+  int si_code;
+
+  union
+  {
+    int _pad[((128 / sizeof (int)) - 3)];
+
+    /* kill() */
+    struct
+    {
+      unsigned int _pid;
+      unsigned int _uid;
+    } _kill;
+
+    /* POSIX.1b timers */
+    struct
+    {
+      compat_timer_t _tid;
+      int _overrun;
+      compat_sigval_t _sigval;
+    } _timer;
+
+    /* POSIX.1b signals */
+    struct
+    {
+      unsigned int _pid;
+      unsigned int _uid;
+      compat_sigval_t _sigval;
+    } _rt;
+
+    /* SIGCHLD */
+    struct
+    {
+      unsigned int _pid;
+      unsigned int _uid;
+      int _status;
+      compat_x32_clock_t _utime;
+      compat_x32_clock_t _stime;
+    } _sigchld;
+
+    /* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
+    struct
+    {
+      unsigned int _addr;
+    } _sigfault;
+
+    /* SIGPOLL */
+    struct
+    {
+      int _band;
+      int _fd;
+    } _sigpoll;
+  } _sifields;
+} compat_x32_siginfo_t __attribute__ ((__aligned__ (8)));
+
+/* To simplify usage of siginfo fields.  */
+
+#define cpt_si_pid _sifields._kill._pid
+#define cpt_si_uid _sifields._kill._uid
+#define cpt_si_timerid _sifields._timer._tid
+#define cpt_si_overrun _sifields._timer._overrun
+#define cpt_si_status _sifields._sigchld._status
+#define cpt_si_utime _sifields._sigchld._utime
+#define cpt_si_stime _sifields._sigchld._stime
+#define cpt_si_ptr _sifields._rt._sigval.sival_ptr
+#define cpt_si_addr _sifields._sigfault._addr
+#define cpt_si_band _sifields._sigpoll._band
+#define cpt_si_fd _sifields._sigpoll._fd
+
+/* glibc at least up to 2.3.2 doesn't have si_timerid, si_overrun.
+   In their place is si_timer1,si_timer2.  */
+
+#ifndef si_timerid
+#define si_timerid si_timer1
+#endif
+#ifndef si_overrun
+#define si_overrun si_timer2
+#endif
+
+/*  Convert the system provided siginfo into compatible siginfo.  */
+
+static void
+compat_siginfo_from_siginfo (compat_siginfo_t *to, siginfo_t *from)
+{
+  memset (to, 0, sizeof (*to));
+
+  to->si_signo = from->si_signo;
+  to->si_errno = from->si_errno;
+  to->si_code = from->si_code;
+
+  if (to->si_code == SI_TIMER)
+    {
+      to->cpt_si_timerid = from->si_timerid;
+      to->cpt_si_overrun = from->si_overrun;
+      to->cpt_si_ptr = (intptr_t) from->si_ptr;
+    }
+  else if (to->si_code == SI_USER)
+    {
+      to->cpt_si_pid = from->si_pid;
+      to->cpt_si_uid = from->si_uid;
+    }
+  else if (to->si_code < 0)
+    {
+      to->cpt_si_pid = from->si_pid;
+      to->cpt_si_uid = from->si_uid;
+      to->cpt_si_ptr = (intptr_t) from->si_ptr;
+    }
+  else
+    {
+      switch (to->si_signo)
+	{
+	case SIGCHLD:
+	  to->cpt_si_pid = from->si_pid;
+	  to->cpt_si_uid = from->si_uid;
+	  to->cpt_si_status = from->si_status;
+	  to->cpt_si_utime = from->si_utime;
+	  to->cpt_si_stime = from->si_stime;
+	  break;
+	case SIGILL:
+	case SIGFPE:
+	case SIGSEGV:
+	case SIGBUS:
+	  to->cpt_si_addr = (intptr_t) from->si_addr;
+	  break;
+	case SIGPOLL:
+	  to->cpt_si_band = from->si_band;
+	  to->cpt_si_fd = from->si_fd;
+	  break;
+	default:
+	  to->cpt_si_pid = from->si_pid;
+	  to->cpt_si_uid = from->si_uid;
+	  to->cpt_si_ptr = (intptr_t) from->si_ptr;
+	  break;
+	}
+    }
+}
+
+/* Convert the compatible siginfo into system siginfo.  */
+
+static void
+siginfo_from_compat_siginfo (siginfo_t *to, compat_siginfo_t *from)
+{
+  memset (to, 0, sizeof (*to));
+
+  to->si_signo = from->si_signo;
+  to->si_errno = from->si_errno;
+  to->si_code = from->si_code;
+
+  if (to->si_code == SI_TIMER)
+    {
+      to->si_timerid = from->cpt_si_timerid;
+      to->si_overrun = from->cpt_si_overrun;
+      to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
+    }
+  else if (to->si_code == SI_USER)
+    {
+      to->si_pid = from->cpt_si_pid;
+      to->si_uid = from->cpt_si_uid;
+    }
+  if (to->si_code < 0)
+    {
+      to->si_pid = from->cpt_si_pid;
+      to->si_uid = from->cpt_si_uid;
+      to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
+    }
+  else
+    {
+      switch (to->si_signo)
+	{
+	case SIGCHLD:
+	  to->si_pid = from->cpt_si_pid;
+	  to->si_uid = from->cpt_si_uid;
+	  to->si_status = from->cpt_si_status;
+	  to->si_utime = from->cpt_si_utime;
+	  to->si_stime = from->cpt_si_stime;
+	  break;
+	case SIGILL:
+	case SIGFPE:
+	case SIGSEGV:
+	case SIGBUS:
+	  to->si_addr = (void *) (intptr_t) from->cpt_si_addr;
+	  break;
+	case SIGPOLL:
+	  to->si_band = from->cpt_si_band;
+	  to->si_fd = from->cpt_si_fd;
+	  break;
+	default:
+	  to->si_pid = from->cpt_si_pid;
+	  to->si_uid = from->cpt_si_uid;
+	  to->si_ptr = (void* ) (intptr_t) from->cpt_si_ptr;
+	  break;
+	}
+    }
+}
+
+/*  Convert the system provided siginfo into compatible x32 siginfo.  */
+
+static void
+compat_x32_siginfo_from_siginfo (compat_x32_siginfo_t *to,
+				 siginfo_t *from)
+{
+  memset (to, 0, sizeof (*to));
+
+  to->si_signo = from->si_signo;
+  to->si_errno = from->si_errno;
+  to->si_code = from->si_code;
+
+  if (to->si_code == SI_TIMER)
+    {
+      to->cpt_si_timerid = from->si_timerid;
+      to->cpt_si_overrun = from->si_overrun;
+      to->cpt_si_ptr = (intptr_t) from->si_ptr;
+    }
+  else if (to->si_code == SI_USER)
+    {
+      to->cpt_si_pid = from->si_pid;
+      to->cpt_si_uid = from->si_uid;
+    }
+  else if (to->si_code < 0)
+    {
+      to->cpt_si_pid = from->si_pid;
+      to->cpt_si_uid = from->si_uid;
+      to->cpt_si_ptr = (intptr_t) from->si_ptr;
+    }
+  else
+    {
+      switch (to->si_signo)
+	{
+	case SIGCHLD:
+	  to->cpt_si_pid = from->si_pid;
+	  to->cpt_si_uid = from->si_uid;
+	  to->cpt_si_status = from->si_status;
+	  memcpy (&to->cpt_si_utime, &from->si_utime,
+		  sizeof (to->cpt_si_utime));
+	  memcpy (&to->cpt_si_stime, &from->si_stime,
+		  sizeof (to->cpt_si_stime));
+	  break;
+	case SIGILL:
+	case SIGFPE:
+	case SIGSEGV:
+	case SIGBUS:
+	  to->cpt_si_addr = (intptr_t) from->si_addr;
+	  break;
+	case SIGPOLL:
+	  to->cpt_si_band = from->si_band;
+	  to->cpt_si_fd = from->si_fd;
+	  break;
+	default:
+	  to->cpt_si_pid = from->si_pid;
+	  to->cpt_si_uid = from->si_uid;
+	  to->cpt_si_ptr = (intptr_t) from->si_ptr;
+	  break;
+	}
+    }
+}
+
+/* Convert the compatible x32 siginfo into system siginfo.  */
+static void
+siginfo_from_compat_x32_siginfo (siginfo_t *to,
+				 compat_x32_siginfo_t *from)
+{
+  memset (to, 0, sizeof (*to));
+
+  to->si_signo = from->si_signo;
+  to->si_errno = from->si_errno;
+  to->si_code = from->si_code;
+
+  if (to->si_code == SI_TIMER)
+    {
+      to->si_timerid = from->cpt_si_timerid;
+      to->si_overrun = from->cpt_si_overrun;
+      to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
+    }
+  else if (to->si_code == SI_USER)
+    {
+      to->si_pid = from->cpt_si_pid;
+      to->si_uid = from->cpt_si_uid;
+    }
+  if (to->si_code < 0)
+    {
+      to->si_pid = from->cpt_si_pid;
+      to->si_uid = from->cpt_si_uid;
+      to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
+    }
+  else
+    {
+      switch (to->si_signo)
+	{
+	case SIGCHLD:
+	  to->si_pid = from->cpt_si_pid;
+	  to->si_uid = from->cpt_si_uid;
+	  to->si_status = from->cpt_si_status;
+	  memcpy (&to->si_utime, &from->cpt_si_utime,
+		  sizeof (to->si_utime));
+	  memcpy (&to->si_stime, &from->cpt_si_stime,
+		  sizeof (to->si_stime));
+	  break;
+	case SIGILL:
+	case SIGFPE:
+	case SIGSEGV:
+	case SIGBUS:
+	  to->si_addr = (void *) (intptr_t) from->cpt_si_addr;
+	  break;
+	case SIGPOLL:
+	  to->si_band = from->cpt_si_band;
+	  to->si_fd = from->cpt_si_fd;
+	  break;
+	default:
+	  to->si_pid = from->cpt_si_pid;
+	  to->si_uid = from->cpt_si_uid;
+	  to->si_ptr = (void* ) (intptr_t) from->cpt_si_ptr;
+	  break;
+	}
+    }
+}
+
+/* Convert a native/host siginfo object, into/from the siginfo in the
+   layout of the inferiors' architecture.  Returns true if any
+   conversion was done; false otherwise.  If DIRECTION is 1, then copy
+   from INF to NATIVE.  If DIRECTION is 0, then copy from NATIVE to INF.  */
+
+int
+amd64_linux_siginfo_fixup_common (siginfo_t *native, gdb_byte *inf,
+				  int direction,
+				  enum amd64_siginfo_fixup_mode mode)
+{
+  if (mode == FIXUP_32)
+    {
+      gdb_assert (sizeof (siginfo_t) == sizeof (compat_siginfo_t));
+
+      if (direction == 0)
+	compat_siginfo_from_siginfo ((struct compat_siginfo *) inf, native);
+      else
+	siginfo_from_compat_siginfo (native, (struct compat_siginfo *) inf);
+
+      return 1;
+    }
+  else if (mode == FIXUP_X32)
+    {
+      gdb_assert (sizeof (siginfo_t) == sizeof (compat_x32_siginfo_t));
+
+      if (direction == 0)
+	compat_x32_siginfo_from_siginfo ((struct compat_x32_siginfo *) inf,
+					 native);
+      else
+	siginfo_from_compat_x32_siginfo (native,
+					 (struct compat_x32_siginfo *) inf);
+
+      return 1;
+    }
+  return 0;
+}
diff --git a/gdb/nat/amd64-linux-siginfo.h b/gdb/nat/amd64-linux-siginfo.h
new file mode 100644
index 0000000..a396966
--- /dev/null
+++ b/gdb/nat/amd64-linux-siginfo.h
@@ -0,0 +1,44 @@
+/* Low-level siginfo manipulation for amd64.
+
+   Copyright (C) 2016 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/>.  */
+
+#ifndef AMD64_LINUX_SIGINFO_H
+#define AMD64_LINUX_SIGINFO_H 1
+
+
+/* When GDB is built as a 64-bit application on Linux, the
+   PTRACE_GETSIGINFO data is always presented in 64-bit layout.  Since
+   debugging a 32-bit inferior with a 64-bit GDB should look the same
+   as debugging it with a 32-bit GDB, we do the 32-bit <-> 64-bit
+   conversion in-place ourselves.  */
+
+/* Kind of siginfo fixup to be performed.  */
+
+enum amd64_siginfo_fixup_mode
+{
+  FIXUP_32 = 1,   /* Fixup for 32bit.  */
+  FIXUP_X32 = 2   /* Fixup for x32.  */
+};
+
+/* Common code for performing the fixup of the siginfo.  */
+
+int amd64_linux_siginfo_fixup_common (siginfo_t *native, gdb_byte *inf,
+				      int direction,
+				      enum amd64_siginfo_fixup_mode mode);
+
+#endif