Implement 32-bit compatibility for waitid(2).

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/linux32.c

@@ -221,6 +221,28 @@ sys32_waitpid(compat_pid_t pid, unsigned int *stat_addr, int options)
 	return compat_sys_wait4(pid, stat_addr, options, NULL);
 }
 
+asmlinkage long
+sysn32_waitid(int which, compat_pid_t pid,
+	      siginfo_t __user *uinfo, int options,
+	      struct compat_rusage __user *uru)
+{
+	struct rusage ru;
+	long ret;
+	mm_segment_t old_fs = get_fs();
+
+	set_fs (KERNEL_DS);
+	ret = sys_waitid(which, pid, uinfo, options,
+			 uru ? (struct rusage __user *) &ru : NULL);
+	set_fs (old_fs);
+
+	if (ret < 0 || uinfo->si_signo == 0)
+		return ret;
+
+	if (uru)
+		ret = put_compat_rusage(&ru, uru);
+	return ret;
+}
+
 struct sysinfo32 {
         s32 uptime;
         u32 loads[3];

arch/mips/kernel/scall64-n32.S

@@ -358,7 +358,7 @@ EXPORT(sysn32_call_table)
 	PTR	compat_sys_mq_notify
 	PTR	compat_sys_mq_getsetattr
 	PTR	sys_ni_syscall			/* 6240, sys_vserver */
-	PTR	sys_waitid
+	PTR	sysn32_waitid
 	PTR	sys_ni_syscall			/* available, was setaltroot */
 	PTR	sys_add_key
 	PTR	sys_request_key

arch/mips/kernel/scall64-o32.S

@@ -480,7 +480,7 @@ sys_call_table:
 	PTR	compat_sys_mq_notify		/* 4275 */
 	PTR	compat_sys_mq_getsetattr
 	PTR	sys_ni_syscall			/* sys_vserver */
-	PTR	sys_waitid
+	PTR	sys32_waitid
 	PTR	sys_ni_syscall			/* available, was setaltroot */
 	PTR	sys_add_key			/* 4280 */
 	PTR	sys_request_key

arch/mips/kernel/signal32.c

@@ -902,3 +902,30 @@ asmlinkage int sys32_rt_sigqueueinfo(int pid, int sig, compat_siginfo_t *uinfo)
 	set_fs (old_fs);
 	return ret;
 }
+
+asmlinkage long
+sys32_waitid(int which, compat_pid_t pid,
+	     compat_siginfo_t __user *uinfo, int options,
+	     struct compat_rusage __user *uru)
+{
+	siginfo_t info;
+	struct rusage ru;
+	long ret;
+	mm_segment_t old_fs = get_fs();
+
+	info.si_signo = 0;
+	set_fs (KERNEL_DS);
+	ret = sys_waitid(which, pid, (siginfo_t __user *) &info, options,
+			 uru ? (struct rusage __user *) &ru : NULL);
+	set_fs (old_fs);
+
+	if (ret < 0 || info.si_signo == 0)
+		return ret;
+
+	if (uru && (ret = put_compat_rusage(&ru, uru)))
+		return ret;
+
+	BUG_ON(info.si_code & __SI_MASK);
+	info.si_code |= __SI_CHLD;
+	return copy_siginfo_to_user32(uinfo, &info);
+}