proc: convert /proc/$PID/syscall to seq_file interface

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/proc/base.c

@@ -482,7 +482,8 @@ static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
 }
 
 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
-static int proc_pid_syscall(struct task_struct *task, char *buffer)
+static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
+			    struct pid *pid, struct task_struct *task)
 {
 	long nr;
 	unsigned long args[6], sp, pc;
@@ -491,11 +492,11 @@ static int proc_pid_syscall(struct task_struct *task, char *buffer)
 		return res;
 
 	if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
-		res = sprintf(buffer, "running\n");
+		seq_puts(m, "running\n");
 	else if (nr < 0)
-		res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
+		seq_printf(m, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
 	else
-		res = sprintf(buffer,
+		seq_printf(m,
 		       "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
 		       nr,
 		       args[0], args[1], args[2], args[3], args[4], args[5],
@@ -2564,7 +2565,7 @@ static const struct pid_entry tgid_base_stuff[] = {
 #endif
 	REG("comm",      S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
-	INF("syscall",    S_IRUSR, proc_pid_syscall),
+	ONE("syscall",    S_IRUSR, proc_pid_syscall),
 #endif
 	INF("cmdline",    S_IRUGO, proc_pid_cmdline),
 	ONE("stat",       S_IRUGO, proc_tgid_stat),
@@ -2900,7 +2901,7 @@ static const struct pid_entry tid_base_stuff[] = {
 #endif
 	REG("comm",      S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
-	INF("syscall",   S_IRUSR, proc_pid_syscall),
+	ONE("syscall",   S_IRUSR, proc_pid_syscall),
 #endif
 	INF("cmdline",   S_IRUGO, proc_pid_cmdline),
 	ONE("stat",      S_IRUGO, proc_tid_stat),