diff options
Diffstat (limited to 'fs/sysfs')
| -rw-r--r-- | fs/sysfs/Kconfig | 23 | ||||
| -rw-r--r-- | fs/sysfs/bin.c | 6 |
2 files changed, 29 insertions, 0 deletions
diff --git a/fs/sysfs/Kconfig b/fs/sysfs/Kconfig new file mode 100644 index 00000000000..f4b67588b9d --- /dev/null +++ b/fs/sysfs/Kconfig @@ -0,0 +1,23 @@ +config SYSFS + bool "sysfs file system support" if EMBEDDED + default y + help + The sysfs filesystem is a virtual filesystem that the kernel uses to + export internal kernel objects, their attributes, and their + relationships to one another. + + Users can use sysfs to ascertain useful information about the running + kernel, such as the devices the kernel has discovered on each bus and + which driver each is bound to. sysfs can also be used to tune devices + and other kernel subsystems. + + Some system agents rely on the information in sysfs to operate. + /sbin/hotplug uses device and object attributes in sysfs to assist in + delegating policy decisions, like persistently naming devices. + + sysfs is currently used by the block subsystem to mount the root + partition. If sysfs is disabled you must specify the boot device on + the kernel boot command line via its major and minor numbers. For + example, "root=03:01" for /dev/hda1. + + Designers of embedded systems may wish to say N here to conserve space. diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c index 66f6e58a7e4..f2c478c3424 100644 --- a/fs/sysfs/bin.c +++ b/fs/sysfs/bin.c @@ -63,6 +63,9 @@ read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off) int count = min_t(size_t, bytes, PAGE_SIZE); char *temp; + if (!bytes) + return 0; + if (size) { if (offs > size) return 0; @@ -131,6 +134,9 @@ static ssize_t write(struct file *file, const char __user *userbuf, int count = min_t(size_t, bytes, PAGE_SIZE); char *temp; + if (!bytes) + return 0; + if (size) { if (offs > size) return 0; |