[AGPGART] Add missing calls to global_flush_tlb() to ali-agp
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / capability.c
blobc8d3c776203490b763c0cc65bd7444a29655804a
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@transmeta.com>
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 <asm/uaccess.h>
17 unsigned securebits = SECUREBITS_DEFAULT; /* systemwide security settings */
18 kernel_cap_t cap_bset = CAP_INIT_EFF_SET;
20 EXPORT_SYMBOL(securebits);
21 EXPORT_SYMBOL(cap_bset);
24 * This lock protects task->cap_* for all tasks including current.
25 * Locking rule: acquire this prior to tasklist_lock.
27 static DEFINE_SPINLOCK(task_capability_lock);
30 * For sys_getproccap() and sys_setproccap(), any of the three
31 * capability set pointers may be NULL -- indicating that that set is
32 * uninteresting and/or not to be changed.
35 /**
36 * sys_capget - get the capabilities of a given process.
37 * @header: pointer to struct that contains capability version and
38 * target pid data
39 * @dataptr: pointer to struct that contains the effective, permitted,
40 * and inheritable capabilities that are returned
42 * Returns 0 on success and < 0 on error.
44 asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr)
46 int ret = 0;
47 pid_t pid;
48 __u32 version;
49 struct task_struct *target;
50 struct __user_cap_data_struct data;
52 if (get_user(version, &header->version))
53 return -EFAULT;
55 if (version != _LINUX_CAPABILITY_VERSION) {
56 if (put_user(_LINUX_CAPABILITY_VERSION, &header->version))
57 return -EFAULT;
58 return -EINVAL;
61 if (get_user(pid, &header->pid))
62 return -EFAULT;
64 if (pid < 0)
65 return -EINVAL;
67 spin_lock(&task_capability_lock);
68 read_lock(&tasklist_lock);
70 if (pid && pid != current->pid) {
71 target = find_task_by_pid(pid);
72 if (!target) {
73 ret = -ESRCH;
74 goto out;
76 } else
77 target = current;
79 ret = security_capget(target, &data.effective, &data.inheritable, &data.permitted);
81 out:
82 read_unlock(&tasklist_lock);
83 spin_unlock(&task_capability_lock);
85 if (!ret && copy_to_user(dataptr, &data, sizeof data))
86 return -EFAULT;
88 return ret;
92 * cap_set_pg - set capabilities for all processes in a given process
93 * group. We call this holding task_capability_lock and tasklist_lock.
95 static inline int cap_set_pg(int pgrp_nr, kernel_cap_t *effective,
96 kernel_cap_t *inheritable,
97 kernel_cap_t *permitted)
99 struct task_struct *g, *target;
100 int ret = -EPERM;
101 int found = 0;
102 struct pid *pgrp;
104 pgrp = find_pid(pgrp_nr);
105 do_each_pid_task(pgrp, PIDTYPE_PGID, g) {
106 target = g;
107 while_each_thread(g, target) {
108 if (!security_capset_check(target, effective,
109 inheritable,
110 permitted)) {
111 security_capset_set(target, effective,
112 inheritable,
113 permitted);
114 ret = 0;
116 found = 1;
118 } while_each_pid_task(pgrp, PIDTYPE_PGID, g);
120 if (!found)
121 ret = 0;
122 return ret;
126 * cap_set_all - set capabilities for all processes other than init
127 * and self. We call this holding task_capability_lock and tasklist_lock.
129 static inline int cap_set_all(kernel_cap_t *effective,
130 kernel_cap_t *inheritable,
131 kernel_cap_t *permitted)
133 struct task_struct *g, *target;
134 int ret = -EPERM;
135 int found = 0;
137 do_each_thread(g, target) {
138 if (target == current || is_init(target))
139 continue;
140 found = 1;
141 if (security_capset_check(target, effective, inheritable,
142 permitted))
143 continue;
144 ret = 0;
145 security_capset_set(target, effective, inheritable, permitted);
146 } while_each_thread(g, target);
148 if (!found)
149 ret = 0;
150 return ret;
154 * sys_capset - set capabilities for a process or a group of processes
155 * @header: pointer to struct that contains capability version and
156 * target pid data
157 * @data: pointer to struct that contains the effective, permitted,
158 * and inheritable capabilities
160 * Set capabilities for a given process, all processes, or all
161 * processes in a given process group.
163 * The restrictions on setting capabilities are specified as:
165 * [pid is for the 'target' task. 'current' is the calling task.]
167 * I: any raised capabilities must be a subset of the (old current) permitted
168 * P: any raised capabilities must be a subset of the (old current) permitted
169 * E: must be set to a subset of (new target) permitted
171 * Returns 0 on success and < 0 on error.
173 asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
175 kernel_cap_t inheritable, permitted, effective;
176 __u32 version;
177 struct task_struct *target;
178 int ret;
179 pid_t pid;
181 if (get_user(version, &header->version))
182 return -EFAULT;
184 if (version != _LINUX_CAPABILITY_VERSION) {
185 if (put_user(_LINUX_CAPABILITY_VERSION, &header->version))
186 return -EFAULT;
187 return -EINVAL;
190 if (get_user(pid, &header->pid))
191 return -EFAULT;
193 if (pid && pid != current->pid && !capable(CAP_SETPCAP))
194 return -EPERM;
196 if (copy_from_user(&effective, &data->effective, sizeof(effective)) ||
197 copy_from_user(&inheritable, &data->inheritable, sizeof(inheritable)) ||
198 copy_from_user(&permitted, &data->permitted, sizeof(permitted)))
199 return -EFAULT;
201 spin_lock(&task_capability_lock);
202 read_lock(&tasklist_lock);
204 if (pid > 0 && pid != current->pid) {
205 target = find_task_by_pid(pid);
206 if (!target) {
207 ret = -ESRCH;
208 goto out;
210 } else
211 target = current;
213 ret = 0;
215 /* having verified that the proposed changes are legal,
216 we now put them into effect. */
217 if (pid < 0) {
218 if (pid == -1) /* all procs other than current and init */
219 ret = cap_set_all(&effective, &inheritable, &permitted);
221 else /* all procs in process group */
222 ret = cap_set_pg(-pid, &effective, &inheritable,
223 &permitted);
224 } else {
225 ret = security_capset_check(target, &effective, &inheritable,
226 &permitted);
227 if (!ret)
228 security_capset_set(target, &effective, &inheritable,
229 &permitted);
232 out:
233 read_unlock(&tasklist_lock);
234 spin_unlock(&task_capability_lock);
236 return ret;
239 int __capable(struct task_struct *t, int cap)
241 if (security_capable(t, cap) == 0) {
242 t->flags |= PF_SUPERPRIV;
243 return 1;
245 return 0;
247 EXPORT_SYMBOL(__capable);
249 int capable(int cap)
251 return __capable(current, cap);
253 EXPORT_SYMBOL(capable);