procfs: Kill BKL in llseek on proc base

We don't use the BKL elsewhere, so use generic_file_llseek
so we can avoid default_llseek taking the BKL.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[restore proc_fdinfo_file_operations as non-seekable]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: John Kacur <jkacur@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>

fs/proc/base.c

@@ -728,6 +728,7 @@ static ssize_t proc_info_read(struct file * file, char __user * buf,
 
 static const struct file_operations proc_info_file_operations = {
 	.read		= proc_info_read,
+	.llseek		= generic_file_llseek,
 };
 
 static int proc_single_show(struct seq_file *m, void *v)
@@ -985,6 +986,7 @@ static ssize_t environ_read(struct file *file, char __user *buf,
 
 static const struct file_operations proc_environ_operations = {
 	.read		= environ_read,
+	.llseek		= generic_file_llseek,
 };
 
 static ssize_t oom_adjust_read(struct file *file, char __user *buf,
@@ -1058,6 +1060,7 @@ static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
 static const struct file_operations proc_oom_adjust_operations = {
 	.read		= oom_adjust_read,
 	.write		= oom_adjust_write,
+	.llseek		= generic_file_llseek,
 };
 
 #ifdef CONFIG_AUDITSYSCALL
@@ -1129,6 +1132,7 @@ static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
 static const struct file_operations proc_loginuid_operations = {
 	.read		= proc_loginuid_read,
 	.write		= proc_loginuid_write,
+	.llseek		= generic_file_llseek,
 };
 
 static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
@@ -1149,6 +1153,7 @@ static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
 
 static const struct file_operations proc_sessionid_operations = {
 	.read		= proc_sessionid_read,
+	.llseek		= generic_file_llseek,
 };
 #endif
 
@@ -1200,6 +1205,7 @@ static ssize_t proc_fault_inject_write(struct file * file,
 static const struct file_operations proc_fault_inject_operations = {
 	.read		= proc_fault_inject_read,
 	.write		= proc_fault_inject_write,
+	.llseek		= generic_file_llseek,
 };
 #endif
 
@@ -1941,7 +1947,7 @@ static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
 }
 
 static const struct file_operations proc_fdinfo_file_operations = {
-	.open		= nonseekable_open,
+	.open           = nonseekable_open,
 	.read		= proc_fdinfo_read,
 };
 
@@ -2225,6 +2231,7 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
 static const struct file_operations proc_pid_attr_operations = {
 	.read		= proc_pid_attr_read,
 	.write		= proc_pid_attr_write,
+	.llseek		= generic_file_llseek,
 };
 
 static const struct pid_entry attr_dir_stuff[] = {
@@ -2345,6 +2352,7 @@ static ssize_t proc_coredump_filter_write(struct file *file,
 static const struct file_operations proc_coredump_filter_operations = {
 	.read		= proc_coredump_filter_read,
 	.write		= proc_coredump_filter_write,
+	.llseek		= generic_file_llseek,
 };
 #endif