[POWERPC] 4xx: logical/bitand typo in powerpc/boot/4xx.c
[linux-2.6/openmoko-kernel/knife-kernel.git] / kernel / capability.c
blobefbd9cdce1322d8a6e0c93ada872d68aadacf38e
1 /*
2 * linux/kernel/capability.c
4 * Copyright (C) 1997 Andrew Main <zefram@fysh.org>
6 * Integrated into 2.1.97+, Andrew G. Morgan <morgan@kernel.org>
7 * 30 May 2002: Cleanup, Robert M. Love <rml@tech9.net>
8 */
10 #include <linux/capability.h>
11 #include <linux/mm.h>
12 #include <linux/module.h>
13 #include <linux/security.h>
14 #include <linux/syscalls.h>
15 #include <linux/pid_namespace.h>
16 #include <asm/uaccess.h>
19 * This lock protects task->cap_* for all tasks including current.
20 * Locking rule: acquire this prior to tasklist_lock.
22 static DEFINE_SPINLOCK(task_capability_lock);
25 * For sys_getproccap() and sys_setproccap(), any of the three
26 * capability set pointers may be NULL -- indicating that that set is
27 * uninteresting and/or not to be changed.
30 /**
31 * sys_capget - get the capabilities of a given process.
32 * @header: pointer to struct that contains capability version and
33 * target pid data
34 * @dataptr: pointer to struct that contains the effective, permitted,
35 * and inheritable capabilities that are returned
37 * Returns 0 on success and < 0 on error.
39 asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr)
41 int ret = 0;
42 pid_t pid;
43 __u32 version;
44 struct task_struct *target;
45 struct __user_cap_data_struct data;
47 if (get_user(version, &header->version))
48 return -EFAULT;
50 if (version != _LINUX_CAPABILITY_VERSION) {
51 if (put_user(_LINUX_CAPABILITY_VERSION, &header->version))
52 return -EFAULT;
53 return -EINVAL;
56 if (get_user(pid, &header->pid))
57 return -EFAULT;
59 if (pid < 0)
60 return -EINVAL;
62 spin_lock(&task_capability_lock);
63 read_lock(&tasklist_lock);
65 if (pid && pid != task_pid_vnr(current)) {
66 target = find_task_by_vpid(pid);
67 if (!target) {
68 ret = -ESRCH;
69 goto out;
71 } else
72 target = current;
74 ret = security_capget(target, &data.effective, &data.inheritable, &data.permitted);
76 out:
77 read_unlock(&tasklist_lock);
78 spin_unlock(&task_capability_lock);
80 if (!ret && copy_to_user(dataptr, &data, sizeof data))
81 return -EFAULT;
83 return ret;
87 * cap_set_pg - set capabilities for all processes in a given process
88 * group. We call this holding task_capability_lock and tasklist_lock.
90 static inline int cap_set_pg(int pgrp_nr, kernel_cap_t *effective,
91 kernel_cap_t *inheritable,
92 kernel_cap_t *permitted)
94 struct task_struct *g, *target;
95 int ret = -EPERM;
96 int found = 0;
97 struct pid *pgrp;
99 pgrp = find_vpid(pgrp_nr);
100 do_each_pid_task(pgrp, PIDTYPE_PGID, g) {
101 target = g;
102 while_each_thread(g, target) {
103 if (!security_capset_check(target, effective,
104 inheritable,
105 permitted)) {
106 security_capset_set(target, effective,
107 inheritable,
108 permitted);
109 ret = 0;
111 found = 1;
113 } while_each_pid_task(pgrp, PIDTYPE_PGID, g);
115 if (!found)
116 ret = 0;
117 return ret;
121 * cap_set_all - set capabilities for all processes other than init
122 * and self. We call this holding task_capability_lock and tasklist_lock.
124 static inline int cap_set_all(kernel_cap_t *effective,
125 kernel_cap_t *inheritable,
126 kernel_cap_t *permitted)
128 struct task_struct *g, *target;
129 int ret = -EPERM;
130 int found = 0;
132 do_each_thread(g, target) {
133 if (target == current || is_container_init(target->group_leader))
134 continue;
135 found = 1;
136 if (security_capset_check(target, effective, inheritable,
137 permitted))
138 continue;
139 ret = 0;
140 security_capset_set(target, effective, inheritable, permitted);
141 } while_each_thread(g, target);
143 if (!found)
144 ret = 0;
145 return ret;
149 * sys_capset - set capabilities for a process or a group of processes
150 * @header: pointer to struct that contains capability version and
151 * target pid data
152 * @data: pointer to struct that contains the effective, permitted,
153 * and inheritable capabilities
155 * Set capabilities for a given process, all processes, or all
156 * processes in a given process group.
158 * The restrictions on setting capabilities are specified as:
160 * [pid is for the 'target' task. 'current' is the calling task.]
162 * I: any raised capabilities must be a subset of the (old current) permitted
163 * P: any raised capabilities must be a subset of the (old current) permitted
164 * E: must be set to a subset of (new target) permitted
166 * Returns 0 on success and < 0 on error.
168 asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
170 kernel_cap_t inheritable, permitted, effective;
171 __u32 version;
172 struct task_struct *target;
173 int ret;
174 pid_t pid;
176 if (get_user(version, &header->version))
177 return -EFAULT;
179 if (version != _LINUX_CAPABILITY_VERSION) {
180 if (put_user(_LINUX_CAPABILITY_VERSION, &header->version))
181 return -EFAULT;
182 return -EINVAL;
185 if (get_user(pid, &header->pid))
186 return -EFAULT;
188 if (pid && pid != task_pid_vnr(current) && !capable(CAP_SETPCAP))
189 return -EPERM;
191 if (copy_from_user(&effective, &data->effective, sizeof(effective)) ||
192 copy_from_user(&inheritable, &data->inheritable, sizeof(inheritable)) ||
193 copy_from_user(&permitted, &data->permitted, sizeof(permitted)))
194 return -EFAULT;
196 spin_lock(&task_capability_lock);
197 read_lock(&tasklist_lock);
199 if (pid > 0 && pid != task_pid_vnr(current)) {
200 target = find_task_by_vpid(pid);
201 if (!target) {
202 ret = -ESRCH;
203 goto out;
205 } else
206 target = current;
208 ret = 0;
210 /* having verified that the proposed changes are legal,
211 we now put them into effect. */
212 if (pid < 0) {
213 if (pid == -1) /* all procs other than current and init */
214 ret = cap_set_all(&effective, &inheritable, &permitted);
216 else /* all procs in process group */
217 ret = cap_set_pg(-pid, &effective, &inheritable,
218 &permitted);
219 } else {
220 ret = security_capset_check(target, &effective, &inheritable,
221 &permitted);
222 if (!ret)
223 security_capset_set(target, &effective, &inheritable,
224 &permitted);
227 out:
228 read_unlock(&tasklist_lock);
229 spin_unlock(&task_capability_lock);
231 return ret;
234 int __capable(struct task_struct *t, int cap)
236 if (security_capable(t, cap) == 0) {
237 t->flags |= PF_SUPERPRIV;
238 return 1;
240 return 0;
243 int capable(int cap)
245 return __capable(current, cap);
247 EXPORT_SYMBOL(capable);