sys_sysfs: Add CONFIG_SYSFS_SYSCALL

sys_sysfs is an obsolete system call no longer supported by libc. - This patch adds a default CONFIG_SYSFS_SYSCALL=y - Option can be turned off in expert mode. - cond_syscall added to kernel/sys_ni.c [[email protected]: tweak Kconfig help text] Signed-off-by: Fabian Frederick <[email protected]> Cc: Randy Dunlap <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
tdeneau · Apr 3, 2014 · 6af9f7b · 6af9f7b
1 parent e3a0cfd
commit 6af9f7b
Show file tree

Hide file tree

Showing 3 changed files with 13 additions and 0 deletions.
diff --git a/fs/filesystems.c b/fs/filesystems.c
@@ -121,6 +121,7 @@ int unregister_filesystem(struct file_system_type * fs)
 
 EXPORT_SYMBOL(unregister_filesystem);
 
+#ifdef CONFIG_SYSFS_SYSCALL
 static int fs_index(const char __user * __name)
 {
 	struct file_system_type * tmp;
@@ -199,6 +200,7 @@ SYSCALL_DEFINE3(sysfs, int, option, unsigned long, arg1, unsigned long, arg2)
 	}
 	return retval;
 }
+#endif
 
 int __init get_filesystem_list(char *buf)
 {

diff --git a/init/Kconfig b/init/Kconfig
@@ -1290,6 +1290,16 @@ config UID16
 	help
 	  This enables the legacy 16-bit UID syscall wrappers.
 
+config SYSFS_SYSCALL
+	bool "Sysfs syscall support" if EXPERT
+	default y
+	---help---
+	  sys_sysfs is an obsolete system call no longer supported in libc.
+	  Note that disabling this option is more secure but might break
+	  compatibility with some systems.
+
+	  If unsure say Y here.
+
 config SYSCTL_SYSCALL
 	bool "Sysctl syscall support" if EXPERT
 	depends on PROC_SYSCTL

diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
@@ -146,6 +146,7 @@ cond_syscall(sys_io_destroy);
 cond_syscall(sys_io_submit);
 cond_syscall(sys_io_cancel);
 cond_syscall(sys_io_getevents);
+cond_syscall(sys_sysfs);
 cond_syscall(sys_syslog);
 cond_syscall(sys_process_vm_readv);
 cond_syscall(sys_process_vm_writev);