diff options
| author | Ludwig Nussel <ludwig.nussel@suse.de> | 2011-02-28 15:57:17 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-04-19 16:45:51 -0700 |
| commit | 088ab0b4d855d68a0f0c16b72fb8e492a533aaa1 (patch) | |
| tree | 7ca0a26573e074ff754b56eaeeb18467fbcc9926 | |
| parent | aed65af1cc2f6fc9ded5a8158f1405a02cf6d2ff (diff) | |
kernel/ksysfs.c: expose file_caps_enabled in sysfs
A kernel booted with no_file_caps allows to install fscaps on a binary
but doesn't actually honor the fscaps when running the binary. Userspace
currently has no sane way to determine whether installing fscaps
actually has any effect. Since parsing /proc/cmdline is fragile this
patch exposes the current setting (1 or 0) via /sys/kernel/fscaps
Signed-off-by: Ludwig Nussel <ludwig.nussel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | Documentation/ABI/testing/sysfs-kernel-fscaps | 8 | ||||
| -rw-r--r-- | kernel/ksysfs.c | 10 |
2 files changed, 18 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-kernel-fscaps b/Documentation/ABI/testing/sysfs-kernel-fscaps new file mode 100644 index 000000000000..50a3033b5e15 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-kernel-fscaps @@ -0,0 +1,8 @@ +What: /sys/kernel/fscaps +Date: February 2011 +KernelVersion: 2.6.38 +Contact: Ludwig Nussel <ludwig.nussel@suse.de> +Description + Shows whether file system capabilities are honored + when executing a binary + diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c index 0b624e791805..3b053c04dd86 100644 --- a/kernel/ksysfs.c +++ b/kernel/ksysfs.c @@ -16,6 +16,7 @@ #include <linux/kexec.h> #include <linux/profile.h> #include <linux/sched.h> +#include <linux/capability.h> #define KERNEL_ATTR_RO(_name) \ static struct kobj_attribute _name##_attr = __ATTR_RO(_name) @@ -131,6 +132,14 @@ KERNEL_ATTR_RO(vmcoreinfo); #endif /* CONFIG_KEXEC */ +/* whether file capabilities are enabled */ +static ssize_t fscaps_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", file_caps_enabled); +} +KERNEL_ATTR_RO(fscaps); + /* * Make /sys/kernel/notes give the raw contents of our kernel .notes section. */ @@ -158,6 +167,7 @@ struct kobject *kernel_kobj; EXPORT_SYMBOL_GPL(kernel_kobj); static struct attribute * kernel_attrs[] = { + &fscaps_attr.attr, #if defined(CONFIG_HOTPLUG) &uevent_seqnum_attr.attr, &uevent_helper_attr.attr, |