linux(4): Rework the definition of struct siginfo to match Linux actual one

Rework the defintion of struct siginfo so that the array padding
struct siginfo to SI_MAX_SIZE can be placed in a union along side of the
rest of the struct siginfo members.  The result is that we no longer need
the __ARCH_SI_PREAMBLE_SIZE or SI_PAD_SIZE definitions.

Move struct siginfo definition under /compat/linux to reduce MD part.
To avoid headers polution include linux_siginfo.h in the MD linux.h

MFC after:		2 weeks

(cherry picked from commit af557e649cf229e45a83767c3c4a7daeb92f0b01)

5 files changed, 121 insertions, 274 deletions

diff --git a/sys/amd64/linux/linux.h b/sys/amd64/linux/linux.h
index 51a2906f45cf..02aede96ce23 100644
--- a/sys/amd64/linux/linux.h
+++ b/sys/amd64/linux/linux.h
@@ -74,6 +74,8 @@ typedef l_int		l_mqd_t;
 typedef l_size_t	l_socklen_t;
 typedef	l_ulong		l_fd_mask;
 
+#include <compat/linux/linux_siginfo.h>
+
 typedef struct {
 	l_int		val[2];
 } l_fsid_t;
@@ -182,75 +184,6 @@ typedef struct {
 	l_size_t	ss_size;
 } l_stack_t;
 
-#define LINUX_SI_PREAMBLE_SIZE	(4 * sizeof(int))
-#define	LINUX_SI_MAX_SIZE	128
-#define	LINUX_SI_PAD_SIZE	((LINUX_SI_MAX_SIZE - \
-				    LINUX_SI_PREAMBLE_SIZE) / sizeof(l_int))
-typedef union l_sigval {
-	l_int		sival_int;
-	l_uintptr_t	sival_ptr;
-} l_sigval_t;
-
-typedef struct l_siginfo {
-	l_int		lsi_signo;
-	l_int		lsi_errno;
-	l_int		lsi_code;
-	union {
-		l_int	_pad[LINUX_SI_PAD_SIZE];
-
-		struct {
-			l_pid_t		_pid;
-			l_uid_t		_uid;
-		} _kill;
-
-		struct {
-			l_timer_t	_tid;
-			l_int		_overrun;
-			char		_pad[sizeof(l_uid_t) - sizeof(int)];
-			union l_sigval	_sigval;
-			l_uint		_sys_private;
-		} _timer;
-
-		struct {
-			l_pid_t		_pid;		/* sender's pid */
-			l_uid_t		_uid;		/* sender's uid */
-			union l_sigval	_sigval;
-		} _rt;
-
-		struct {
-			l_pid_t		_pid;		/* which child */
-			l_uid_t		_uid;		/* sender's uid */
-			l_int		_status;	/* exit code */
-			l_clock_t	_utime;
-			l_clock_t	_stime;
-		} _sigchld;
-
-		struct {
-			l_uintptr_t	_addr;	/* Faulting insn/memory ref. */
-		} _sigfault;
-
-		struct {
-			l_long		_band;	/* POLL_IN,POLL_OUT,POLL_MSG */
-			l_int		_fd;
-		} _sigpoll;
-	} _sifields;
-} l_siginfo_t;
-
-#define	lsi_pid		_sifields._kill._pid
-#define	lsi_uid		_sifields._kill._uid
-#define	lsi_tid		_sifields._timer._tid
-#define	lsi_overrun	_sifields._timer._overrun
-#define	lsi_sys_private	_sifields._timer._sys_private
-#define	lsi_status	_sifields._sigchld._status
-#define	lsi_utime	_sifields._sigchld._utime
-#define	lsi_stime	_sifields._sigchld._stime
-#define	lsi_value	_sifields._rt._sigval
-#define	lsi_int		_sifields._rt._sigval.sival_int
-#define	lsi_ptr		_sifields._rt._sigval.sival_ptr
-#define	lsi_addr	_sifields._sigfault._addr
-#define	lsi_band	_sifields._sigpoll._band
-#define	lsi_fd		_sifields._sigpoll._fd
-
 /*
  * mount flags
  */
diff --git a/sys/amd64/linux32/linux.h b/sys/amd64/linux32/linux.h
index 1987ff515275..5cdf7624fef5 100644
--- a/sys/amd64/linux32/linux.h
+++ b/sys/amd64/linux32/linux.h
@@ -82,6 +82,8 @@ typedef l_int		l_timer_t;
 typedef l_int		l_mqd_t;
 typedef	l_ulong		l_fd_mask;
 
+#include <compat/linux/linux_siginfo.h>
+
 typedef struct {
 	l_int		val[2];
 } l_fsid_t;
@@ -287,74 +289,6 @@ typedef struct {
 	l_size_t	ss_size;
 } l_stack_t;
 
-#define	LINUX_SI_MAX_SIZE	128
-#define	LINUX_SI_PAD_SIZE	((LINUX_SI_MAX_SIZE/sizeof(l_int)) - 3)
-
-typedef union l_sigval {
-	l_int		sival_int;
-	l_uintptr_t	sival_ptr;
-} l_sigval_t;
-
-typedef struct l_siginfo {
-	l_int		lsi_signo;
-	l_int		lsi_errno;
-	l_int		lsi_code;
-	union {
-		l_int	_pad[LINUX_SI_PAD_SIZE];
-
-		struct {
-			l_pid_t		_pid;
-			l_uid_t		_uid;
-		} _kill;
-
-		struct {
-			l_timer_t	_tid;
-			l_int		_overrun;
-			char		_pad[sizeof(l_uid_t) - sizeof(l_int)];
-			l_sigval_t	_sigval;
-			l_int		_sys_private;
-		} _timer;
-
-		struct {
-			l_pid_t		_pid;		/* sender's pid */
-			l_uid_t		_uid;		/* sender's uid */
-			l_sigval_t	_sigval;
-		} _rt;
-
-		struct {
-			l_pid_t		_pid;		/* which child */
-			l_uid_t		_uid;		/* sender's uid */
-			l_int		_status;	/* exit code */
-			l_clock_t	_utime;
-			l_clock_t	_stime;
-		} _sigchld;
-
-		struct {
-			l_uintptr_t	_addr;	/* Faulting insn/memory ref. */
-		} _sigfault;
-
-		struct {
-			l_long		_band;	/* POLL_IN,POLL_OUT,POLL_MSG */
-			l_int		_fd;
-		} _sigpoll;
-	} _sifields;
-} l_siginfo_t;
-
-#define	lsi_pid		_sifields._kill._pid
-#define	lsi_uid		_sifields._kill._uid
-#define	lsi_tid		_sifields._timer._tid
-#define	lsi_overrun	_sifields._timer._overrun
-#define	lsi_sys_private	_sifields._timer._sys_private
-#define	lsi_status	_sifields._sigchld._status
-#define	lsi_utime	_sifields._sigchld._utime
-#define	lsi_stime	_sifields._sigchld._stime
-#define	lsi_value	_sifields._rt._sigval
-#define	lsi_int		_sifields._rt._sigval.sival_int
-#define	lsi_ptr		_sifields._rt._sigval.sival_ptr
-#define	lsi_addr	_sifields._sigfault._addr
-#define	lsi_band	_sifields._sigpoll._band
-#define	lsi_fd		_sifields._sigpoll._fd
-
 /*
  * arch specific open/fcntl flags
  */
diff --git a/sys/arm64/linux/linux.h b/sys/arm64/linux/linux.h
index b6e2af506ad2..402f7aa39bb9 100644
--- a/sys/arm64/linux/linux.h
+++ b/sys/arm64/linux/linux.h
@@ -67,6 +67,8 @@ typedef l_int		l_timer_t;	/* XXX */
 typedef l_int		l_mqd_t;
 typedef l_ulong		l_fd_mask;
 
+#include <compat/linux/linux_siginfo.h>
+
 typedef struct {
 	l_int		val[2];
 } l_fsid_t;
@@ -179,75 +181,6 @@ typedef struct {
 	l_size_t	ss_size;
 } l_stack_t;
 
-#define	LINUX_SI_PREAMBLE_SIZE	(4 * sizeof(int))
-#define	LINUX_SI_MAX_SIZE	128
-#define	LINUX_SI_PAD_SIZE	((LINUX_SI_MAX_SIZE - \
-				    LINUX_SI_PREAMBLE_SIZE) / sizeof(l_int))
-typedef union l_sigval {
-	l_int		sival_int;
-	l_uintptr_t	sival_ptr;
-} l_sigval_t;
-
-typedef struct l_siginfo {
-	l_int		lsi_signo;
-	l_int		lsi_errno;
-	l_int		lsi_code;
-	union {
-		l_int	_pad[LINUX_SI_PAD_SIZE];
-
-		struct {
-			l_pid_t		_pid;
-			l_uid_t		_uid;
-		} _kill;
-
-		struct {
-			l_timer_t	_tid;
-			l_int		_overrun;
-			char		_pad[sizeof(l_uid_t) - sizeof(int)];
-			union l_sigval	_sigval;
-			l_uint		_sys_private;
-		} _timer;
-
-		struct {
-			l_pid_t		_pid;		/* sender's pid */
-			l_uid_t		_uid;		/* sender's uid */
-			union l_sigval	_sigval;
-		} _rt;
-
-		struct {
-			l_pid_t		_pid;		/* which child */
-			l_uid_t		_uid;		/* sender's uid */
-			l_int		_status;	/* exit code */
-			l_clock_t	_utime;
-			l_clock_t	_stime;
-		} _sigchld;
-
-		struct {
-			l_uintptr_t	_addr;	/* Faulting insn/memory ref. */
-		} _sigfault;
-
-		struct {
-			l_long		_band;	/* POLL_IN,POLL_OUT,POLL_MSG */
-			l_int		_fd;
-		} _sigpoll;
-	} _sifields;
-} l_siginfo_t;
-
-#define	lsi_pid		_sifields._kill._pid
-#define	lsi_uid		_sifields._kill._uid
-#define	lsi_tid		_sifields._timer._tid
-#define	lsi_overrun	_sifields._timer._overrun
-#define	lsi_sys_private	_sifields._timer._sys_private
-#define	lsi_status	_sifields._sigchld._status
-#define	lsi_utime	_sifields._sigchld._utime
-#define	lsi_stime	_sifields._sigchld._stime
-#define	lsi_value	_sifields._rt._sigval
-#define	lsi_int		_sifields._rt._sigval.sival_int
-#define	lsi_ptr		_sifields._rt._sigval.sival_ptr
-#define	lsi_addr	_sifields._sigfault._addr
-#define	lsi_band	_sifields._sigpoll._band
-#define	lsi_fd		_sifields._sigpoll._fd
-
 union l_semun {
 	l_int		val;
 	l_uintptr_t	buf;
diff --git a/sys/compat/linux/linux_siginfo.h b/sys/compat/linux/linux_siginfo.h
new file mode 100644
index 000000000000..cb5c3e76482c
--- /dev/null
+++ b/sys/compat/linux/linux_siginfo.h
@@ -0,0 +1,113 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 2004 Tim J. Robbins
+ * Copyright (c) 2001 Doug Rabson
+ * Copyright (c) 1994-1996 Søren Schmidt
+ * All rights reserved.
+ * Copyright (c) 2022 Dmitry Chagin <dchagin@FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer
+ *    in this position and unchanged.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _LINUX_SIGINFO_H_
+#define _LINUX_SIGINFO_H_
+
+typedef union l_sigval {
+	l_int		sival_int;
+	l_uintptr_t	sival_ptr;
+} l_sigval_t;
+
+#define	LINUX_SI_MAX_SIZE		128
+
+union __sifields {
+	struct {
+		l_pid_t		_pid;
+		l_uid_t		_uid;
+	} _kill;
+
+	struct {
+		l_timer_t	_tid;
+		l_int		_overrun;
+		char		_pad[sizeof(l_uid_t) - sizeof(int)];
+		union l_sigval	_sigval;
+		l_uint		_sys_private;
+	} _timer;
+
+	struct {
+		l_pid_t		_pid;		/* sender's pid */
+		l_uid_t		_uid;		/* sender's uid */
+		union l_sigval	_sigval;
+	} _rt;
+
+	struct {
+		l_pid_t		_pid;		/* which child */
+		l_uid_t		_uid;		/* sender's uid */
+		l_int		_status;	/* exit code */
+		l_clock_t	_utime;
+		l_clock_t	_stime;
+	} _sigchld;
+
+	struct {
+		l_uintptr_t	_addr;	/* Faulting insn/memory ref. */
+	} _sigfault;
+
+	struct {
+		l_long		_band;	/* POLL_IN,POLL_OUT,POLL_MSG */
+		l_int		_fd;
+	} _sigpoll;
+};
+
+typedef struct l_siginfo {
+	union {
+		struct {
+			l_int		lsi_signo;
+			l_int		lsi_errno;
+			l_int		lsi_code;
+			union __sifields _sifields;
+		};
+		l_int	_pad[LINUX_SI_MAX_SIZE/sizeof(l_int)];
+	};
+} l_siginfo_t;
+
+_Static_assert(sizeof(l_siginfo_t) == LINUX_SI_MAX_SIZE, "l_siginfo_t size");
+
+#define	lsi_pid		_sifields._kill._pid
+#define	lsi_uid		_sifields._kill._uid
+#define	lsi_tid		_sifields._timer._tid
+#define	lsi_overrun	_sifields._timer._overrun
+#define	lsi_sys_private	_sifields._timer._sys_private
+#define	lsi_status	_sifields._sigchld._status
+#define	lsi_utime	_sifields._sigchld._utime
+#define	lsi_stime	_sifields._sigchld._stime
+#define	lsi_value	_sifields._rt._sigval
+#define	lsi_int		_sifields._rt._sigval.sival_int
+#define	lsi_ptr		_sifields._rt._sigval.sival_ptr
+#define	lsi_addr	_sifields._sigfault._addr
+#define	lsi_band	_sifields._sigpoll._band
+#define	lsi_fd		_sifields._sigpoll._fd
+
+#endif /* _LINUX_SIGINFO_H_ */
diff --git a/sys/i386/linux/linux.h b/sys/i386/linux/linux.h
index 75995587373b..210fb6ca5778 100644
--- a/sys/i386/linux/linux.h
+++ b/sys/i386/linux/linux.h
@@ -74,6 +74,8 @@ typedef l_int		l_timer_t;
 typedef l_int		l_mqd_t;
 typedef	l_ulong		l_fd_mask;
 
+#include <compat/linux/linux_siginfo.h>
+
 typedef struct {
 	l_int		val[2];
 } l_fsid_t;
@@ -260,74 +262,6 @@ typedef struct {
 	l_size_t	ss_size;
 } l_stack_t;
 
-#define	LINUX_SI_MAX_SIZE	128
-#define	LINUX_SI_PAD_SIZE	((LINUX_SI_MAX_SIZE/sizeof(l_int)) - 3)
-
-typedef union l_sigval {
-	l_int		sival_int;
-	l_uintptr_t	sival_ptr;
-} l_sigval_t;
-
-typedef struct l_siginfo {
-	l_int		lsi_signo;
-	l_int		lsi_errno;
-	l_int		lsi_code;
-	union {
-		l_int	_pad[LINUX_SI_PAD_SIZE];
-
-		struct {
-			l_pid_t		_pid;
-			l_uid_t		_uid;
-		} _kill;
-
-		struct {
-			l_timer_t	_tid;
-			l_int		_overrun;
-			char		_pad[sizeof(l_uid_t) - sizeof(l_int)];
-			l_sigval_t	_sigval;
-			l_int		_sys_private;
-		} _timer;
-
-		struct {
-			l_pid_t		_pid;		/* sender's pid */
-			l_uid_t		_uid;		/* sender's uid */
-			l_sigval_t	_sigval;
-		} _rt;
-
-		struct {
-			l_pid_t		_pid;		/* which child */
-			l_uid_t		_uid;		/* sender's uid */
-			l_int		_status;	/* exit code */
-			l_clock_t	_utime;
-			l_clock_t	_stime;
-		} _sigchld;
-
-		struct {
-			l_uintptr_t	_addr;	/* Faulting insn/memory ref. */
-		} _sigfault;
-
-		struct {
-			l_long		_band;	/* POLL_IN,POLL_OUT,POLL_MSG */
-			l_int		_fd;
-		} _sigpoll;
-	} _sifields;
-} l_siginfo_t;
-
-#define	lsi_pid		_sifields._kill._pid
-#define	lsi_uid		_sifields._kill._uid
-#define	lsi_tid		_sifields._timer._tid
-#define	lsi_overrun	_sifields._timer._overrun
-#define	lsi_sys_private	_sifields._timer._sys_private
-#define	lsi_status	_sifields._sigchld._status
-#define	lsi_utime	_sifields._sigchld._utime
-#define	lsi_stime	_sifields._sigchld._stime
-#define	lsi_value	_sifields._rt._sigval
-#define	lsi_int		_sifields._rt._sigval.sival_int
-#define	lsi_ptr		_sifields._rt._sigval.sival_ptr
-#define	lsi_addr	_sifields._sigfault._addr
-#define	lsi_band	_sifields._sigpoll._band
-#define	lsi_fd		_sifields._sigpoll._fd
-
 extern struct sysentvec linux_sysvec;
 
 /*