4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.gnu.org/licenses/gpl-2.0.html
23 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Use is subject to license terms.
26 * Copyright (c) 2012, 2015, Intel Corporation.
29 * This file is part of Lustre, http://www.lustre.org/
30 * Lustre is a trademark of Sun Microsystems, Inc.
32 * libcfs/libcfs/linux/linux-curproc.c
34 * Lustre curproc API implementation for Linux kernel
36 * Author: Nikita Danilov <nikita@clusterfs.com>
39 #include <linux/sched.h>
40 #include <linux/fs_struct.h>
42 #include <linux/compat.h>
43 #include <linux/thread_info.h>
45 #define DEBUG_SUBSYSTEM S_LNET
47 #include <libcfs/libcfs.h>
50 * Implementation of cfs_curproc API (see portals/include/libcfs/curproc.h)
54 /* Currently all the CFS_CAP_* defines match CAP_* ones. */
55 #define cfs_cap_pack(cap) (cap)
56 #define cfs_cap_unpack(cap) (cap)
58 void cfs_cap_raise(cfs_cap_t cap)
61 if ((cred = prepare_creds())) {
62 cap_raise(cred->cap_effective, cfs_cap_unpack(cap));
67 void cfs_cap_lower(cfs_cap_t cap)
70 if ((cred = prepare_creds())) {
71 cap_lower(cred->cap_effective, cfs_cap_unpack(cap));
76 int cfs_cap_raised(cfs_cap_t cap)
78 return cap_raised(current_cap(), cfs_cap_unpack(cap));
81 static void cfs_kernel_cap_pack(kernel_cap_t kcap, cfs_cap_t *cap)
83 #if defined (_LINUX_CAPABILITY_VERSION) && _LINUX_CAPABILITY_VERSION == 0x19980330
84 *cap = cfs_cap_pack(kcap);
85 #elif defined (_LINUX_CAPABILITY_VERSION) && _LINUX_CAPABILITY_VERSION == 0x20071026
86 *cap = cfs_cap_pack(kcap[0]);
87 #elif defined(_KERNEL_CAPABILITY_VERSION) && _KERNEL_CAPABILITY_VERSION == 0x20080522
88 /* XXX lost high byte */
89 *cap = cfs_cap_pack(kcap.cap[0]);
91 #error "need correct _KERNEL_CAPABILITY_VERSION "
95 static void cfs_kernel_cap_unpack(kernel_cap_t *kcap, cfs_cap_t cap)
97 #if defined (_LINUX_CAPABILITY_VERSION) && _LINUX_CAPABILITY_VERSION == 0x19980330
98 *kcap = cfs_cap_unpack(cap);
99 #elif defined (_LINUX_CAPABILITY_VERSION) && _LINUX_CAPABILITY_VERSION == 0x20071026
100 (*kcap)[0] = cfs_cap_unpack(cap);
101 #elif defined(_KERNEL_CAPABILITY_VERSION) && _KERNEL_CAPABILITY_VERSION == 0x20080522
102 kcap->cap[0] = cfs_cap_unpack(cap);
104 #error "need correct _KERNEL_CAPABILITY_VERSION "
108 cfs_cap_t cfs_curproc_cap_pack(void)
111 cfs_kernel_cap_pack(current_cap(), &cap);
115 void cfs_curproc_cap_unpack(cfs_cap_t cap)
118 if ((cred = prepare_creds())) {
119 cfs_kernel_cap_unpack(&cred->cap_effective, cap);
124 int cfs_capable(cfs_cap_t cap)
126 return capable(cfs_cap_unpack(cap));
129 static int cfs_access_process_vm(struct task_struct *tsk,
130 struct mm_struct *mm,
132 void *buf, int len, int write)
134 /* Just copied from kernel for the kernels which doesn't
135 * have access_process_vm() exported */
136 struct vm_area_struct *vma;
140 /* Avoid deadlocks on mmap_sem if called from sys_mmap_pgoff(),
141 * which is already holding mmap_sem for writes. If some other
142 * thread gets the write lock in the meantime, this thread will
143 * block, but at least it won't deadlock on itself. LU-1735 */
144 if (down_read_trylock(&mm->mmap_sem) == 0)
147 /* ignore errors, just check how much was successfully transferred */
149 int bytes, rc, offset;
152 #if defined(HAVE_GET_USER_PAGES_GUP_FLAGS)
153 rc = get_user_pages(addr, 1, write ? FOLL_WRITE : 0, &page, &vma);
154 #elif defined(HAVE_GET_USER_PAGES_6ARG)
155 rc = get_user_pages(addr, 1, write, 1, &page, &vma);
157 rc = get_user_pages(tsk, mm, addr, 1, write, 1, &page, &vma);
163 offset = addr & (PAGE_SIZE-1);
164 if (bytes > PAGE_SIZE-offset)
165 bytes = PAGE_SIZE-offset;
169 copy_to_user_page(vma, page, addr,
170 maddr + offset, buf, bytes);
171 set_page_dirty_lock(page);
173 copy_from_user_page(vma, page, addr,
174 buf, maddr + offset, bytes);
182 up_read(&mm->mmap_sem);
184 return buf - old_buf;
187 /* Read the environment variable of current process specified by @key. */
188 int cfs_get_environ(const char *key, char *value, int *val_len)
190 struct mm_struct *mm;
192 int buf_len = PAGE_SIZE;
193 int key_len = strlen(key);
199 buffer = kmalloc(buf_len, GFP_USER);
203 mm = get_task_mm(current);
209 addr = mm->env_start;
210 while (addr < mm->env_end) {
211 int this_len, retval, scan_len;
212 char *env_start, *env_end;
214 memset(buffer, 0, buf_len);
216 this_len = min_t(int, mm->env_end - addr, buf_len);
217 retval = cfs_access_process_vm(current, mm, addr, buffer,
220 GOTO(out, rc = retval);
221 else if (retval != this_len)
226 /* Parse the buffer to find out the specified key/value pair.
227 * The "key=value" entries are separated by '\0'. */
234 env_end = memscan(env_start, '\0', scan_len);
235 LASSERT(env_end >= env_start &&
236 env_end <= env_start + scan_len);
238 /* The last entry of this buffer cross the buffer
239 * boundary, reread it in next cycle. */
240 if (unlikely(env_end - env_start == scan_len)) {
241 /* Just skip the entry larger than page size,
242 * it can't be jobID env variable. */
243 if (unlikely(scan_len == this_len))
248 } else if (unlikely(skip)) {
254 entry_len = env_end - env_start;
256 /* Key length + length of '=' */
257 if (entry_len > key_len + 1 &&
258 !memcmp(entry, key, key_len)) {
259 entry += key_len + 1;
260 entry_len -= key_len + 1;
261 /* The 'value' buffer passed in is too small.*/
262 if (entry_len >= *val_len)
263 GOTO(out, rc = -EOVERFLOW);
265 memcpy(value, entry, entry_len);
266 *val_len = entry_len;
270 scan_len -= (env_end - env_start + 1);
271 env_start = env_end + 1;
274 GOTO(out, rc = -ENOENT);
278 kfree((void *)buffer);
281 EXPORT_SYMBOL(cfs_get_environ);
283 EXPORT_SYMBOL(cfs_cap_raise);
284 EXPORT_SYMBOL(cfs_cap_lower);
285 EXPORT_SYMBOL(cfs_cap_raised);
286 EXPORT_SYMBOL(cfs_curproc_cap_pack);
287 EXPORT_SYMBOL(cfs_capable);
291 * c-indentation-style: "K&R"