diff options
Diffstat (limited to 'drivers/staging/lustre/lustre/libcfs/linux/linux-curproc.c')
| -rw-r--r-- | drivers/staging/lustre/lustre/libcfs/linux/linux-curproc.c | 339 |
1 files changed, 339 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lustre/libcfs/linux/linux-curproc.c b/drivers/staging/lustre/lustre/libcfs/linux/linux-curproc.c new file mode 100644 index 000000000000..f236510a2f3f --- /dev/null +++ b/drivers/staging/lustre/lustre/libcfs/linux/linux-curproc.c @@ -0,0 +1,339 @@ +/* + * GPL HEADER START + * + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 only, + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License version 2 for more details (a copy is included + * in the LICENSE file that accompanied this code). + * + * You should have received a copy of the GNU General Public License + * version 2 along with this program; If not, see + * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + * GPL HEADER END + */ +/* + * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved. + * Use is subject to license terms. + * + * Copyright (c) 2011, 2012, Intel Corporation. + */ +/* + * This file is part of Lustre, http://www.lustre.org/ + * Lustre is a trademark of Sun Microsystems, Inc. + * + * libcfs/libcfs/linux/linux-curproc.c + * + * Lustre curproc API implementation for Linux kernel + * + * Author: Nikita Danilov <nikita@clusterfs.com> + */ + +#include <linux/sched.h> +#include <linux/fs_struct.h> + +#include <linux/compat.h> +#include <linux/thread_info.h> + +#define DEBUG_SUBSYSTEM S_LNET + +#include <linux/libcfs/libcfs.h> + +/* + * Implementation of cfs_curproc API (see portals/include/libcfs/curproc.h) + * for Linux kernel. + */ + +int cfs_curproc_groups_nr(void) +{ + int nr; + + task_lock(current); + nr = current_cred()->group_info->ngroups; + task_unlock(current); + return nr; +} + +void cfs_curproc_groups_dump(gid_t *array, int size) +{ + task_lock(current); + size = min_t(int, size, current_cred()->group_info->ngroups); + memcpy(array, current_cred()->group_info->blocks[0], size * sizeof(__u32)); + task_unlock(current); +} + + +int current_is_in_group(gid_t gid) +{ + return in_group_p(gid); +} + +/* Currently all the CFS_CAP_* defines match CAP_* ones. */ +#define cfs_cap_pack(cap) (cap) +#define cfs_cap_unpack(cap) (cap) + +void cfs_cap_raise(cfs_cap_t cap) +{ + struct cred *cred; + if ((cred = prepare_creds())) { + cap_raise(cred->cap_effective, cfs_cap_unpack(cap)); + commit_creds(cred); + } +} + +void cfs_cap_lower(cfs_cap_t cap) +{ + struct cred *cred; + if ((cred = prepare_creds())) { + cap_lower(cred->cap_effective, cfs_cap_unpack(cap)); + commit_creds(cred); + } +} + +int cfs_cap_raised(cfs_cap_t cap) +{ + return cap_raised(current_cap(), cfs_cap_unpack(cap)); +} + +void cfs_kernel_cap_pack(kernel_cap_t kcap, cfs_cap_t *cap) +{ +#if defined (_LINUX_CAPABILITY_VERSION) && _LINUX_CAPABILITY_VERSION == 0x19980330 + *cap = cfs_cap_pack(kcap); +#elif defined (_LINUX_CAPABILITY_VERSION) && _LINUX_CAPABILITY_VERSION == 0x20071026 + *cap = cfs_cap_pack(kcap[0]); +#elif defined(_KERNEL_CAPABILITY_VERSION) && _KERNEL_CAPABILITY_VERSION == 0x20080522 + /* XXX lost high byte */ + *cap = cfs_cap_pack(kcap.cap[0]); +#else + #error "need correct _KERNEL_CAPABILITY_VERSION " +#endif +} + +void cfs_kernel_cap_unpack(kernel_cap_t *kcap, cfs_cap_t cap) +{ +#if defined (_LINUX_CAPABILITY_VERSION) && _LINUX_CAPABILITY_VERSION == 0x19980330 + *kcap = cfs_cap_unpack(cap); +#elif defined (_LINUX_CAPABILITY_VERSION) && _LINUX_CAPABILITY_VERSION == 0x20071026 + (*kcap)[0] = cfs_cap_unpack(cap); +#elif defined(_KERNEL_CAPABILITY_VERSION) && _KERNEL_CAPABILITY_VERSION == 0x20080522 + kcap->cap[0] = cfs_cap_unpack(cap); +#else + #error "need correct _KERNEL_CAPABILITY_VERSION " +#endif +} + +cfs_cap_t cfs_curproc_cap_pack(void) +{ + cfs_cap_t cap; + cfs_kernel_cap_pack(current_cap(), &cap); + return cap; +} + +void cfs_curproc_cap_unpack(cfs_cap_t cap) +{ + struct cred *cred; + if ((cred = prepare_creds())) { + cfs_kernel_cap_unpack(&cred->cap_effective, cap); + commit_creds(cred); + } +} + +int cfs_capable(cfs_cap_t cap) +{ + return capable(cfs_cap_unpack(cap)); +} + +/* Check if task is running in 32-bit API mode, for the purpose of + * userspace binary interfaces. On 32-bit Linux this is (unfortunately) + * always true, even if the application is using LARGEFILE64 and 64-bit + * APIs, because Linux provides no way for the filesystem to know if it + * is called via 32-bit or 64-bit APIs. Other clients may vary. On + * 64-bit systems, this will only be true if the binary is calling a + * 32-bit system call. */ +int current_is_32bit(void) +{ + return is_compat_task(); +} + +static int cfs_access_process_vm(struct task_struct *tsk, unsigned long addr, + void *buf, int len, int write) +{ + /* Just copied from kernel for the kernels which doesn't + * have access_process_vm() exported */ + struct mm_struct *mm; + struct vm_area_struct *vma; + struct page *page; + void *old_buf = buf; + + mm = get_task_mm(tsk); + if (!mm) + return 0; + + down_read(&mm->mmap_sem); + /* ignore errors, just check how much was sucessfully transfered */ + while (len) { + int bytes, rc, offset; + void *maddr; + + rc = get_user_pages(tsk, mm, addr, 1, + write, 1, &page, &vma); + if (rc <= 0) + break; + + bytes = len; + offset = addr & (PAGE_SIZE-1); + if (bytes > PAGE_SIZE-offset) + bytes = PAGE_SIZE-offset; + + maddr = kmap(page); + if (write) { + copy_to_user_page(vma, page, addr, + maddr + offset, buf, bytes); + set_page_dirty_lock(page); + } else { + copy_from_user_page(vma, page, addr, + buf, maddr + offset, bytes); + } + kunmap(page); + page_cache_release(page); + len -= bytes; + buf += bytes; + addr += bytes; + } + up_read(&mm->mmap_sem); + mmput(mm); + + return buf - old_buf; +} + +/* Read the environment variable of current process specified by @key. */ +int cfs_get_environ(const char *key, char *value, int *val_len) +{ + struct mm_struct *mm; + char *buffer, *tmp_buf = NULL; + int buf_len = PAGE_CACHE_SIZE; + int key_len = strlen(key); + unsigned long addr; + int rc; + ENTRY; + + buffer = kmalloc(buf_len, GFP_USER); + if (!buffer) + RETURN(-ENOMEM); + + mm = get_task_mm(current); + if (!mm) { + kfree(buffer); + RETURN(-EINVAL); + } + + /* Avoid deadlocks on mmap_sem if called from sys_mmap_pgoff(), + * which is already holding mmap_sem for writes. If some other + * thread gets the write lock in the meantime, this thread will + * block, but at least it won't deadlock on itself. LU-1735 */ + if (down_read_trylock(&mm->mmap_sem) == 0) + return -EDEADLK; + up_read(&mm->mmap_sem); + + addr = mm->env_start; + while (addr < mm->env_end) { + int this_len, retval, scan_len; + char *env_start, *env_end; + + memset(buffer, 0, buf_len); + + this_len = min_t(int, mm->env_end - addr, buf_len); + retval = cfs_access_process_vm(current, addr, buffer, + this_len, 0); + if (retval != this_len) + break; + + addr += retval; + + /* Parse the buffer to find out the specified key/value pair. + * The "key=value" entries are separated by '\0'. */ + env_start = buffer; + scan_len = this_len; + while (scan_len) { + char *entry; + int entry_len; + + env_end = memscan(env_start, '\0', scan_len); + LASSERT(env_end >= env_start && + env_end <= env_start + scan_len); + + /* The last entry of this buffer cross the buffer + * boundary, reread it in next cycle. */ + if (unlikely(env_end - env_start == scan_len)) { + /* This entry is too large to fit in buffer */ + if (unlikely(scan_len == this_len)) { + CERROR("Too long env variable.\n"); + GOTO(out, rc = -EINVAL); + } + addr -= scan_len; + break; + } + + entry = env_start; + entry_len = env_end - env_start; + + /* Key length + length of '=' */ + if (entry_len > key_len + 1 && + !memcmp(entry, key, key_len)) { + entry += key_len + 1; + entry_len -= key_len + 1; + /* The 'value' buffer passed in is too small.*/ + if (entry_len >= *val_len) + GOTO(out, rc = -EOVERFLOW); + + memcpy(value, entry, entry_len); + *val_len = entry_len; + GOTO(out, rc = 0); + } + + scan_len -= (env_end - env_start + 1); + env_start = env_end + 1; + } + } + GOTO(out, rc = -ENOENT); + +out: + mmput(mm); + kfree((void *)buffer); + if (tmp_buf) + kfree((void *)tmp_buf); + return rc; +} +EXPORT_SYMBOL(cfs_get_environ); + +EXPORT_SYMBOL(cfs_curproc_groups_nr); +EXPORT_SYMBOL(cfs_curproc_groups_dump); +EXPORT_SYMBOL(current_is_in_group); +EXPORT_SYMBOL(cfs_cap_raise); +EXPORT_SYMBOL(cfs_cap_lower); +EXPORT_SYMBOL(cfs_cap_raised); +EXPORT_SYMBOL(cfs_curproc_cap_pack); +EXPORT_SYMBOL(cfs_curproc_cap_unpack); +EXPORT_SYMBOL(cfs_capable); +EXPORT_SYMBOL(current_is_32bit); + +/* + * Local variables: + * c-indentation-style: "K&R" + * c-basic-offset: 8 + * tab-width: 8 + * fill-column: 80 + * scroll-step: 1 + * End: + */ |