MIPS: Clean up compat_siginfo_t

While mips can't use the generic compat_siginfo_t directly because
its si_code and si_errno are inverted, we can still make it as
close to the generic version as possible. This makes it easier
to update when new members are added to siginfo_t.

The main changes are adding a missing _sigsys union member and
eliminating the unused _irix_sigchld one.

Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11455/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Author: Amanieu

arch/mips/include/asm/compat.h

@@ -130,6 +130,8 @@ typedef union compat_sigval {
 	compat_uptr_t	sival_ptr;
 } compat_sigval_t;
 
+/* Can't use the generic version because si_code and si_errno are swapped */
+
 #define SI_PAD_SIZE32	(128/sizeof(int) - 3)
 
 typedef struct compat_siginfo {
@@ -138,57 +140,61 @@ typedef struct compat_siginfo {
 	int si_errno;
 
 	union {
-		int _pad[SI_PAD_SIZE32];
+		int _pad[128 / sizeof(int) - 3];
 
 		/* kill() */
 		struct {
 			compat_pid_t _pid;	/* sender's pid */
-			__compat_uid_t _uid;	/* sender's uid */
+			__compat_uid32_t _uid;	/* sender's uid */
 		} _kill;
 
+		/* POSIX.1b timers */
+		struct {
+			compat_timer_t _tid;	/* timer id */
+			int _overrun;		/* overrun count */
+			compat_sigval_t _sigval;	/* same as below */
+		} _timer;
+
+		/* POSIX.1b signals */
+		struct {
+			compat_pid_t _pid;	/* sender's pid */
+			__compat_uid32_t _uid;	/* sender's uid */
+			compat_sigval_t _sigval;
+		} _rt;
+
 		/* SIGCHLD */
 		struct {
 			compat_pid_t _pid;	/* which child */
-			__compat_uid_t _uid;	/* sender's uid */
+			__compat_uid32_t _uid;	/* sender's uid */
 			int _status;		/* exit code */
 			compat_clock_t _utime;
 			compat_clock_t _stime;
 		} _sigchld;
 
-		/* IRIX SIGCHLD */
-		struct {
-			compat_pid_t _pid;	/* which child */
-			compat_clock_t _utime;
-			int _status;		/* exit code */
-			compat_clock_t _stime;
-		} _irix_sigchld;
-
 		/* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
 		struct {
-			s32 _addr; /* faulting insn/memory ref. */
+			compat_uptr_t _addr;	/* faulting insn/memory ref. */
+#ifdef __ARCH_SI_TRAPNO
+			int _trapno;	/* TRAP # which caused the signal */
+#endif
+			short _addr_lsb; /* LSB of the reported address */
+			struct {
+				compat_uptr_t _lower;
+				compat_uptr_t _upper;
+			} _addr_bnd;
 		} _sigfault;
 
-		/* SIGPOLL, SIGXFSZ (To do ...)	 */
+		/* SIGPOLL */
 		struct {
-			int _band;	/* POLL_IN, POLL_OUT, POLL_MSG */
+			compat_long_t _band; /* POLL_IN, POLL_OUT, POLL_MSG */
 			int _fd;
 		} _sigpoll;
 
-		/* POSIX.1b timers */
-		struct {
-			timer_t _tid;		/* timer id */
-			int _overrun;		/* overrun count */
-			compat_sigval_t _sigval;/* same as below */
-			int _sys_private;	/* not to be passed to user */
-		} _timer;
-
-		/* POSIX.1b signals */
 		struct {
-			compat_pid_t _pid;	/* sender's pid */
-			__compat_uid_t _uid;	/* sender's uid */
-			compat_sigval_t _sigval;
-		} _rt;
-
+			compat_uptr_t _call_addr; /* calling insn */
+			int _syscall;	/* triggering system call number */
+			compat_uint_t _arch;	/* AUDIT_ARCH_* of syscall */
+		} _sigsys;
 	} _sifields;
 } compat_siginfo_t;