Adaptation of siginfo fixup for the new bnd fields

New bnds fields will be always present for x86 architecture.
Fixup for compatibility layer 32bits has to be fixed.

It was added the nat_siginfo to serving as intermediate step
between kernel provided siginfo and the fix up routine.

When executing compat_siginfo_from_siginfo or
compat_x32_siginfo_from_siginfo first the buffer read from the kernel are
converted into the nat_signfo for homogenization, then the fields of
nat_siginfo are use to set the compat and compat_x32 siginfo fields.

In other to make this conversion independent of the system where gdb
is compiled the most complete version of the siginfo, named as native
siginfo, is used internally as an intermediate step.

Conversion using nat_siginfo is exemplified below:

compat_siginfo_from_siginfo or compat_x32_siginfo_from_siginfo:

buffer (from the kernel) -> nat_siginfo -> 32 / X32 siginfo
                      (memcpy)       (field by field)

siginfo_from_compat_x32_siginfo or siginfo_from_compat_siginfo:

32 / X32 siginfo -> nat_siginfo -> buffer (to the kernel)
          (field by field)    (memcpy)

Caveat: No support for MPX on x32.

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

gdb/ChangeLog:

	* amd64-linux-siginfo.c (nat_siginfo_t, nat_sigval_t, nat_timeval):
	New types.
	(compat_siginfo): New bound fields added.
	(compat_x32_siginfo): New field added.
	(cpt_si_addr_lsb): New define.
	(compat_siginfo_from_siginfo): Use nat_siginfo.
	(siginfo_from_compat_siginfo): Use nat_siginfo.
	(compat_x32_siginfo_from_siginfo): Likewise.
	(siginfo_from_compat_x32_siginfo): Likewise.

3 files changed, 240 insertions, 102 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 56bdc79..3c97ac2 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,17 @@
 2016-02-02  Walfred Tedeschi  <walfred.tedeschi@intel.com>
 
+	* amd64-linux-siginfo.c (nat_siginfo_t, nat_sigval_t, nat_timeval):
+	New types.
+	(compat_siginfo): New bound fields added.
+	(compat_x32_siginfo): New field added.
+	(cpt_si_addr_lsb): New define.
+	(compat_siginfo_from_siginfo): Use nat_siginfo.
+	(siginfo_from_compat_siginfo): Use nat_siginfo.
+	(compat_x32_siginfo_from_siginfo): Likewise.
+	(siginfo_from_compat_x32_siginfo): Likewise.
+
+2016-02-02  Walfred Tedeschi  <walfred.tedeschi@intel.com>
+
 	* linux-tdep.c (linux_get_siginfo_type): Add the _addr_bnd
 	structure to the siginfo if extra_fields contains
 	LINUX_SIGINFO_FIELD_ADDR_BND.
diff --git a/gdb/nat/amd64-linux-siginfo.c b/gdb/nat/amd64-linux-siginfo.c
index 36b5505..72b3042 100644
--- a/gdb/nat/amd64-linux-siginfo.c
+++ b/gdb/nat/amd64-linux-siginfo.c
@@ -21,6 +21,97 @@
 #include "common-defs.h"
 #include "amd64-linux-siginfo.h"
 
+/* The nat_* types below define the most complete kernel siginfo type
+   known for the architecture, independent of the system/libc headers.  */
+
+typedef int nat_int_t;
+typedef void* nat_uptr_t;
+
+typedef int nat_time_t;
+typedef int nat_timer_t;
+
+/* For native 64-bit, clock_t in _sigchld is 64bit aligned at 4 bytes.  */
+typedef long __attribute__ ((__aligned__ (4))) nat_clock_t;
+
+struct nat_timeval
+{
+  nat_time_t tv_sec;
+  int tv_usec;
+};
+
+typedef union nat_sigval
+{
+  nat_int_t sival_int;
+  nat_uptr_t sival_ptr;
+} nat_sigval_t;
+
+typedef struct nat_siginfo
+{
+  int si_signo;
+  int si_errno;
+  int si_code;
+
+  union
+  {
+    int _pad[((128 / sizeof (int)) - 4)];
+    /* kill() */
+    struct
+    {
+      unsigned int _pid;
+      unsigned int _uid;
+    } _kill;
+
+    /* POSIX.1b timers */
+    struct
+    {
+      nat_timer_t _tid;
+      int _overrun;
+      nat_sigval_t _sigval;
+    } _timer;
+
+    /* POSIX.1b signals */
+    struct
+    {
+      unsigned int _pid;
+      unsigned int _uid;
+      nat_sigval_t _sigval;
+    } _rt;
+
+    /* SIGCHLD */
+    struct
+    {
+      unsigned int _pid;
+      unsigned int _uid;
+      int _status;
+      nat_clock_t _utime;
+      nat_clock_t _stime;
+    } _sigchld;
+
+    /* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
+    struct
+    {
+      nat_uptr_t _addr;
+      short int _addr_lsb;
+      struct
+      {
+	nat_uptr_t _lower;
+	nat_uptr_t _upper;
+      } si_addr_bnd;
+    } _sigfault;
+
+    /* SIGPOLL */
+    struct
+    {
+      int _band;
+      int _fd;
+    } _sigpoll;
+  } _sifields;
+} nat_siginfo_t __attribute__ ((__aligned__ (8)));
+
+/*  Sanity check for the siginfo structure size.  */
+
+gdb_static_assert (sizeof (nat_siginfo_t) == sizeof (siginfo_t));
+
 /* These types below (compat_*) define a siginfo type that is layout
    compatible with the siginfo type exported by the 32-bit userspace
    support.  */
@@ -91,6 +182,12 @@ typedef struct compat_siginfo
     struct
     {
       unsigned int _addr;
+      short int _addr_lsb;
+      struct
+      {
+	unsigned int _lower;
+	unsigned int _upper;
+      } si_addr_bnd;
     } _sigfault;
 
     /* SIGPOLL */
@@ -152,6 +249,7 @@ typedef struct compat_x32_siginfo
     struct
     {
       unsigned int _addr;
+      unsigned int _addr_lsb;
     } _sigfault;
 
     /* SIGPOLL */
@@ -174,6 +272,7 @@ typedef struct compat_x32_siginfo
 #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_addr_lsb _sifields._sigfault._addr_lsb
 #define cpt_si_band _sifields._sigpoll._band
 #define cpt_si_fd _sifields._sigpoll._fd
 
@@ -192,54 +291,57 @@ typedef struct compat_x32_siginfo
 static void
 compat_siginfo_from_siginfo (compat_siginfo_t *to, siginfo_t *from)
 {
+  nat_siginfo_t from_nat;
+
+  memcpy (&from_nat, from, sizeof (from_nat));
   memset (to, 0, sizeof (*to));
 
-  to->si_signo = from->si_signo;
-  to->si_errno = from->si_errno;
-  to->si_code = from->si_code;
+  to->si_signo = from_nat.si_signo;
+  to->si_errno = from_nat.si_errno;
+  to->si_code = from_nat.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;
+      to->cpt_si_timerid = from_nat.cpt_si_timerid;
+      to->cpt_si_overrun = from_nat.cpt_si_overrun;
+      to->cpt_si_ptr = (intptr_t) from_nat.cpt_si_ptr;
     }
   else if (to->si_code == SI_USER)
     {
-      to->cpt_si_pid = from->si_pid;
-      to->cpt_si_uid = from->si_uid;
+      to->cpt_si_pid = from_nat.cpt_si_pid;
+      to->cpt_si_uid = from_nat.cpt_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;
+      to->cpt_si_pid = from_nat.cpt_si_pid;
+      to->cpt_si_uid = from_nat.cpt_si_uid;
+      to->cpt_si_ptr = (intptr_t) from_nat.cpt_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;
+	  to->cpt_si_pid = from_nat.cpt_si_pid;
+	  to->cpt_si_uid = from_nat.cpt_si_uid;
+	  to->cpt_si_status = from_nat.cpt_si_status;
+	  to->cpt_si_utime = from_nat.cpt_si_utime;
+	  to->cpt_si_stime = from_nat.cpt_si_stime;
 	  break;
 	case SIGILL:
 	case SIGFPE:
 	case SIGSEGV:
 	case SIGBUS:
-	  to->cpt_si_addr = (intptr_t) from->si_addr;
+	  to->cpt_si_addr = (intptr_t) from_nat.cpt_si_addr;
 	  break;
 	case SIGPOLL:
-	  to->cpt_si_band = from->si_band;
-	  to->cpt_si_fd = from->si_fd;
+	  to->cpt_si_band = from_nat.cpt_si_band;
+	  to->cpt_si_fd = from_nat.cpt_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;
+	  to->cpt_si_pid = from_nat.cpt_si_pid;
+	  to->cpt_si_uid = from_nat.cpt_si_uid;
+	  to->cpt_si_ptr = (intptr_t) from_nat.cpt_si_ptr;
 	  break;
 	}
     }
@@ -250,57 +352,61 @@ compat_siginfo_from_siginfo (compat_siginfo_t *to, siginfo_t *from)
 static void
 siginfo_from_compat_siginfo (siginfo_t *to, compat_siginfo_t *from)
 {
-  memset (to, 0, sizeof (*to));
+  nat_siginfo_t to_nat;
 
-  to->si_signo = from->si_signo;
-  to->si_errno = from->si_errno;
-  to->si_code = from->si_code;
+  memset (&to_nat, 0, sizeof (to_nat));
 
-  if (to->si_code == SI_TIMER)
+  to_nat.si_signo = from->si_signo;
+  to_nat.si_errno = from->si_errno;
+  to_nat.si_code = from->si_code;
+
+  if (to_nat.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;
+      to_nat.cpt_si_timerid = from->cpt_si_timerid;
+      to_nat.cpt_si_overrun = from->cpt_si_overrun;
+      to_nat.cpt_si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
     }
-  else if (to->si_code == SI_USER)
+  else if (to_nat.si_code == SI_USER)
     {
-      to->si_pid = from->cpt_si_pid;
-      to->si_uid = from->cpt_si_uid;
+      to_nat.cpt_si_pid = from->cpt_si_pid;
+      to_nat.cpt_si_uid = from->cpt_si_uid;
     }
-  if (to->si_code < 0)
+  if (to_nat.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;
+      to_nat.cpt_si_pid = from->cpt_si_pid;
+      to_nat.cpt_si_uid = from->cpt_si_uid;
+      to_nat.cpt_si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
     }
   else
     {
-      switch (to->si_signo)
+      switch (to_nat.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;
+	  to_nat.cpt_si_pid = from->cpt_si_pid;
+	  to_nat.cpt_si_uid = from->cpt_si_uid;
+	  to_nat.cpt_si_status = from->cpt_si_status;
+	  to_nat.cpt_si_utime = from->cpt_si_utime;
+	  to_nat.cpt_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;
+	  to_nat.cpt_si_addr = (void *) (intptr_t) from->cpt_si_addr;
+	  to_nat.cpt_si_addr_lsb = (short) from->cpt_si_addr_lsb;
 	  break;
 	case SIGPOLL:
-	  to->si_band = from->cpt_si_band;
-	  to->si_fd = from->cpt_si_fd;
+	  to_nat.cpt_si_band = from->cpt_si_band;
+	  to_nat.cpt_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;
+	  to_nat.cpt_si_pid = from->cpt_si_pid;
+	  to_nat.cpt_si_uid = from->cpt_si_uid;
+	  to_nat.cpt_si_ptr = (void* ) (intptr_t) from->cpt_si_ptr;
 	  break;
 	}
     }
+  memcpy (to, &to_nat, sizeof (to_nat));
 }
 
 /*  Convert the system provided siginfo into compatible x32 siginfo.  */
@@ -309,119 +415,127 @@ static void
 compat_x32_siginfo_from_siginfo (compat_x32_siginfo_t *to,
 				 siginfo_t *from)
 {
+  nat_siginfo_t from_nat;
+
+  memcpy (&from_nat, from, sizeof (from_nat));
   memset (to, 0, sizeof (*to));
 
-  to->si_signo = from->si_signo;
-  to->si_errno = from->si_errno;
-  to->si_code = from->si_code;
+  to->si_signo = from_nat.si_signo;
+  to->si_errno = from_nat.si_errno;
+  to->si_code = from_nat.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;
+      to->cpt_si_timerid = from_nat.cpt_si_timerid;
+      to->cpt_si_overrun = from_nat.cpt_si_overrun;
+      to->cpt_si_ptr = (intptr_t) from_nat.cpt_si_ptr;
     }
   else if (to->si_code == SI_USER)
     {
-      to->cpt_si_pid = from->si_pid;
-      to->cpt_si_uid = from->si_uid;
+      to->cpt_si_pid = from_nat.cpt_si_pid;
+      to->cpt_si_uid = from_nat.cpt_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;
+      to->cpt_si_pid = from_nat.cpt_si_pid;
+      to->cpt_si_uid = from_nat.cpt_si_uid;
+      to->cpt_si_ptr = (intptr_t) from_nat.cpt_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,
+	  to->cpt_si_pid = from_nat.cpt_si_pid;
+	  to->cpt_si_uid = from_nat.cpt_si_uid;
+	  to->cpt_si_status = from_nat.cpt_si_status;
+	  memcpy (&to->cpt_si_utime, &from_nat.cpt_si_utime,
 		  sizeof (to->cpt_si_utime));
-	  memcpy (&to->cpt_si_stime, &from->si_stime,
+	  memcpy (&to->cpt_si_stime, &from_nat.cpt_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;
+	  to->cpt_si_addr = (intptr_t) from_nat.cpt_si_addr;
 	  break;
 	case SIGPOLL:
-	  to->cpt_si_band = from->si_band;
-	  to->cpt_si_fd = from->si_fd;
+	  to->cpt_si_band = from_nat.cpt_si_band;
+	  to->cpt_si_fd = from_nat.cpt_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;
+	  to->cpt_si_pid = from_nat.cpt_si_pid;
+	  to->cpt_si_uid = from_nat.cpt_si_uid;
+	  to->cpt_si_ptr = (intptr_t) from_nat.cpt_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));
+  nat_siginfo_t to_nat;
 
-  to->si_signo = from->si_signo;
-  to->si_errno = from->si_errno;
-  to->si_code = from->si_code;
+  memset (&to_nat, 0, sizeof (to_nat));
+  to_nat.si_signo = from->si_signo;
+  to_nat.si_errno = from->si_errno;
+  to_nat.si_code = from->si_code;
 
-  if (to->si_code == SI_TIMER)
+  if (to_nat.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;
+      to_nat.cpt_si_timerid = from->cpt_si_timerid;
+      to_nat.cpt_si_overrun = from->cpt_si_overrun;
+      to_nat.cpt_si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
     }
-  else if (to->si_code == SI_USER)
+  else if (to_nat.si_code == SI_USER)
     {
-      to->si_pid = from->cpt_si_pid;
-      to->si_uid = from->cpt_si_uid;
+      to_nat.cpt_si_pid = from->cpt_si_pid;
+      to_nat.cpt_si_uid = from->cpt_si_uid;
     }
-  if (to->si_code < 0)
+  if (to_nat.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;
+      to_nat.cpt_si_pid = from->cpt_si_pid;
+      to_nat.cpt_si_uid = from->cpt_si_uid;
+      to_nat.cpt_si_ptr = (void *) (intptr_t) from->cpt_si_ptr;
     }
   else
     {
-      switch (to->si_signo)
+      switch (to_nat.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));
+	  to_nat.cpt_si_pid = from->cpt_si_pid;
+	  to_nat.cpt_si_uid = from->cpt_si_uid;
+	  to_nat.cpt_si_status = from->cpt_si_status;
+	  memcpy (&to_nat.cpt_si_utime, &from->cpt_si_utime,
+		  sizeof (to_nat.cpt_si_utime));
+	  memcpy (&to_nat.cpt_si_stime, &from->cpt_si_stime,
+		  sizeof (to_nat.cpt_si_stime));
 	  break;
 	case SIGILL:
 	case SIGFPE:
 	case SIGSEGV:
 	case SIGBUS:
-	  to->si_addr = (void *) (intptr_t) from->cpt_si_addr;
+	  to_nat.cpt_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;
+	  to_nat.cpt_si_band = from->cpt_si_band;
+	  to_nat.cpt_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;
+	  to_nat.cpt_si_pid = from->cpt_si_pid;
+	  to_nat.cpt_si_uid = from->cpt_si_uid;
+	  to_nat.cpt_si_ptr = (void* ) (intptr_t) from->cpt_si_ptr;
 	  break;
 	}
     }
+  memcpy (to, &to_nat, sizeof (to_nat));
 }
 
 /* Convert a native/host siginfo object, into/from the siginfo in the
diff --git a/gdb/nat/amd64-linux-siginfo.h b/gdb/nat/amd64-linux-siginfo.h
index a396966..5b29cbe 100644
--- a/gdb/nat/amd64-linux-siginfo.h
+++ b/gdb/nat/amd64-linux-siginfo.h
@@ -20,12 +20,24 @@
 #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.  */
+   conversion in-place ourselves.
+   In other to make this conversion independent of the system where gdb
+   is compiled the most complete version of the siginfo, named as native
+   siginfo, is used internally as an intermediate step.
+
+   Conversion using nat_siginfo is exemplified below:
+   compat_siginfo_from_siginfo or compat_x32_siginfo_from_siginfo
+
+      buffer (from the kernel) -> nat_siginfo -> 32 / X32 siginfo
+
+   siginfo_from_compat_x32_siginfo or siginfo_from_compat_siginfo
+
+     32 / X32 siginfo -> nat_siginfo -> buffer (to the kernel)  */
+
 
 /* Kind of siginfo fixup to be performed.  */