Messages in this thread Patch in this message | | | From | Francis Laniel <> | Subject | [RFC PATCH v1 2/2] kernel/ksysfs.c: Add capabilities attribute. | Date | Mon, 27 Dec 2021 21:55:00 +0100 |
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This new read-only attribute prints the capabilities values with their names: 0 CAP_CHOWN 1 CAP_DAC_OVERRIDE ... 39 CAP_BPF
Signed-off-by: Francis Laniel <flaniel@linux.microsoft.com> --- kernel/ksysfs.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c index 35859da8bd4f..7d39794a55bc 100644 --- a/kernel/ksysfs.c +++ b/kernel/ksysfs.c @@ -182,6 +182,23 @@ static ssize_t rcu_normal_store(struct kobject *kobj, KERNEL_ATTR_RW(rcu_normal); #endif /* #ifndef CONFIG_TINY_RCU */ +static ssize_t capabilities_show(struct kobject *unused0, + struct kobj_attribute *unused1, char *buf) +{ + int at = 0; + int i; + + for (i = 0; i < CAP_LAST_CAP; i++) { + if (at >= PAGE_SIZE) + return at; + + at += sysfs_emit_at(buf, at, "%d\t%s\n", i, cap_strings[i]); + } + + return at; +} +KERNEL_ATTR_RO(capabilities); + /* * Make /sys/kernel/notes give the raw contents of our kernel .notes section. */ @@ -229,6 +246,7 @@ static struct attribute * kernel_attrs[] = { &rcu_expedited_attr.attr, &rcu_normal_attr.attr, #endif + &capabilities_attr.attr, NULL }; -- 2.30.2
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