| /* |
| * drivers/misc/logger.c |
| * |
| * A Logging Subsystem |
| * |
| * Copyright (C) 2007-2008 Google, Inc. |
| * |
| * Robert Love <rlove@google.com> |
| * |
| * This software is licensed under the terms of the GNU General Public |
| * License version 2, as published by the Free Software Foundation, and |
| * may be copied, distributed, and modified under those terms. |
| * |
| * 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 for more details. |
| */ |
| |
| #define pr_fmt(fmt) "logger: " fmt |
| |
| #include <linux/sched.h> |
| #include <linux/module.h> |
| #include <linux/fs.h> |
| #include <linux/miscdevice.h> |
| #include <linux/uaccess.h> |
| #include <linux/poll.h> |
| #include <linux/slab.h> |
| #include <linux/time.h> |
| #include <linux/vmalloc.h> |
| #include <linux/aio.h> |
| #include "logger.h" |
| |
| #include <asm/ioctls.h> |
| |
| /** |
| * struct logger_log - represents a specific log, such as 'main' or 'radio' |
| * @buffer: The actual ring buffer |
| * @misc: The "misc" device representing the log |
| * @wq: The wait queue for @readers |
| * @readers: This log's readers |
| * @mutex: The mutex that protects the @buffer |
| * @w_off: The current write head offset |
| * @head: The head, or location that readers start reading at. |
| * @size: The size of the log |
| * @logs: The list of log channels |
| * |
| * This structure lives from module insertion until module removal, so it does |
| * not need additional reference counting. The structure is protected by the |
| * mutex 'mutex'. |
| */ |
| struct logger_log { |
| unsigned char *buffer; |
| struct miscdevice misc; |
| wait_queue_head_t wq; |
| struct list_head readers; |
| struct mutex mutex; |
| size_t w_off; |
| size_t head; |
| size_t size; |
| struct list_head logs; |
| }; |
| |
| static LIST_HEAD(log_list); |
| |
| |
| /** |
| * struct logger_reader - a logging device open for reading |
| * @log: The associated log |
| * @list: The associated entry in @logger_log's list |
| * @r_off: The current read head offset. |
| * @r_all: Reader can read all entries |
| * @r_ver: Reader ABI version |
| * |
| * This object lives from open to release, so we don't need additional |
| * reference counting. The structure is protected by log->mutex. |
| */ |
| struct logger_reader { |
| struct logger_log *log; |
| struct list_head list; |
| size_t r_off; |
| bool r_all; |
| int r_ver; |
| }; |
| |
| /* logger_offset - returns index 'n' into the log via (optimized) modulus */ |
| static size_t logger_offset(struct logger_log *log, size_t n) |
| { |
| return n & (log->size - 1); |
| } |
| |
| |
| /* |
| * file_get_log - Given a file structure, return the associated log |
| * |
| * This isn't aesthetic. We have several goals: |
| * |
| * 1) Need to quickly obtain the associated log during an I/O operation |
| * 2) Readers need to maintain state (logger_reader) |
| * 3) Writers need to be very fast (open() should be a near no-op) |
| * |
| * In the reader case, we can trivially go file->logger_reader->logger_log. |
| * For a writer, we don't want to maintain a logger_reader, so we just go |
| * file->logger_log. Thus what file->private_data points at depends on whether |
| * or not the file was opened for reading. This function hides that dirtiness. |
| */ |
| static inline struct logger_log *file_get_log(struct file *file) |
| { |
| if (file->f_mode & FMODE_READ) { |
| struct logger_reader *reader = file->private_data; |
| return reader->log; |
| } else |
| return file->private_data; |
| } |
| |
| /* |
| * get_entry_header - returns a pointer to the logger_entry header within |
| * 'log' starting at offset 'off'. A temporary logger_entry 'scratch' must |
| * be provided. Typically the return value will be a pointer within |
| * 'logger->buf'. However, a pointer to 'scratch' may be returned if |
| * the log entry spans the end and beginning of the circular buffer. |
| */ |
| static struct logger_entry *get_entry_header(struct logger_log *log, |
| size_t off, struct logger_entry *scratch) |
| { |
| size_t len = min(sizeof(struct logger_entry), log->size - off); |
| if (len != sizeof(struct logger_entry)) { |
| memcpy(((void *) scratch), log->buffer + off, len); |
| memcpy(((void *) scratch) + len, log->buffer, |
| sizeof(struct logger_entry) - len); |
| return scratch; |
| } |
| |
| return (struct logger_entry *) (log->buffer + off); |
| } |
| |
| /* |
| * get_entry_msg_len - Grabs the length of the message of the entry |
| * starting from from 'off'. |
| * |
| * An entry length is 2 bytes (16 bits) in host endian order. |
| * In the log, the length does not include the size of the log entry structure. |
| * This function returns the size including the log entry structure. |
| * |
| * Caller needs to hold log->mutex. |
| */ |
| static __u32 get_entry_msg_len(struct logger_log *log, size_t off) |
| { |
| struct logger_entry scratch; |
| struct logger_entry *entry; |
| |
| entry = get_entry_header(log, off, &scratch); |
| return entry->len; |
| } |
| |
| static size_t get_user_hdr_len(int ver) |
| { |
| if (ver < 2) |
| return sizeof(struct user_logger_entry_compat); |
| else |
| return sizeof(struct logger_entry); |
| } |
| |
| static ssize_t copy_header_to_user(int ver, struct logger_entry *entry, |
| char __user *buf) |
| { |
| void *hdr; |
| size_t hdr_len; |
| struct user_logger_entry_compat v1; |
| |
| if (ver < 2) { |
| v1.len = entry->len; |
| v1.__pad = 0; |
| v1.pid = entry->pid; |
| v1.tid = entry->tid; |
| v1.sec = entry->sec; |
| v1.nsec = entry->nsec; |
| hdr = &v1; |
| hdr_len = sizeof(struct user_logger_entry_compat); |
| } else { |
| hdr = entry; |
| hdr_len = sizeof(struct logger_entry); |
| } |
| |
| return copy_to_user(buf, hdr, hdr_len); |
| } |
| |
| /* |
| * do_read_log_to_user - reads exactly 'count' bytes from 'log' into the |
| * user-space buffer 'buf'. Returns 'count' on success. |
| * |
| * Caller must hold log->mutex. |
| */ |
| static ssize_t do_read_log_to_user(struct logger_log *log, |
| struct logger_reader *reader, |
| char __user *buf, |
| size_t count) |
| { |
| struct logger_entry scratch; |
| struct logger_entry *entry; |
| size_t len; |
| size_t msg_start; |
| |
| /* |
| * First, copy the header to userspace, using the version of |
| * the header requested |
| */ |
| entry = get_entry_header(log, reader->r_off, &scratch); |
| if (copy_header_to_user(reader->r_ver, entry, buf)) |
| return -EFAULT; |
| |
| count -= get_user_hdr_len(reader->r_ver); |
| buf += get_user_hdr_len(reader->r_ver); |
| msg_start = logger_offset(log, |
| reader->r_off + sizeof(struct logger_entry)); |
| |
| /* |
| * We read from the msg in two disjoint operations. First, we read from |
| * the current msg head offset up to 'count' bytes or to the end of |
| * the log, whichever comes first. |
| */ |
| len = min(count, log->size - msg_start); |
| if (copy_to_user(buf, log->buffer + msg_start, len)) |
| return -EFAULT; |
| |
| /* |
| * Second, we read any remaining bytes, starting back at the head of |
| * the log. |
| */ |
| if (count != len) |
| if (copy_to_user(buf + len, log->buffer, count - len)) |
| return -EFAULT; |
| |
| reader->r_off = logger_offset(log, reader->r_off + |
| sizeof(struct logger_entry) + count); |
| |
| return count + get_user_hdr_len(reader->r_ver); |
| } |
| |
| /* |
| * get_next_entry_by_uid - Starting at 'off', returns an offset into |
| * 'log->buffer' which contains the first entry readable by 'euid' |
| */ |
| static size_t get_next_entry_by_uid(struct logger_log *log, |
| size_t off, kuid_t euid) |
| { |
| while (off != log->w_off) { |
| struct logger_entry *entry; |
| struct logger_entry scratch; |
| size_t next_len; |
| |
| entry = get_entry_header(log, off, &scratch); |
| |
| if (uid_eq(entry->euid, euid)) |
| return off; |
| |
| next_len = sizeof(struct logger_entry) + entry->len; |
| off = logger_offset(log, off + next_len); |
| } |
| |
| return off; |
| } |
| |
| /* |
| * logger_read - our log's read() method |
| * |
| * Behavior: |
| * |
| * - O_NONBLOCK works |
| * - If there are no log entries to read, blocks until log is written to |
| * - Atomically reads exactly one log entry |
| * |
| * Will set errno to EINVAL if read |
| * buffer is insufficient to hold next entry. |
| */ |
| static ssize_t logger_read(struct file *file, char __user *buf, |
| size_t count, loff_t *pos) |
| { |
| struct logger_reader *reader = file->private_data; |
| struct logger_log *log = reader->log; |
| ssize_t ret; |
| DEFINE_WAIT(wait); |
| |
| start: |
| while (1) { |
| mutex_lock(&log->mutex); |
| |
| prepare_to_wait(&log->wq, &wait, TASK_INTERRUPTIBLE); |
| |
| ret = (log->w_off == reader->r_off); |
| mutex_unlock(&log->mutex); |
| if (!ret) |
| break; |
| |
| if (file->f_flags & O_NONBLOCK) { |
| ret = -EAGAIN; |
| break; |
| } |
| |
| if (signal_pending(current)) { |
| ret = -EINTR; |
| break; |
| } |
| |
| schedule(); |
| } |
| |
| finish_wait(&log->wq, &wait); |
| if (ret) |
| return ret; |
| |
| mutex_lock(&log->mutex); |
| |
| if (!reader->r_all) |
| reader->r_off = get_next_entry_by_uid(log, |
| reader->r_off, current_euid()); |
| |
| /* is there still something to read or did we race? */ |
| if (unlikely(log->w_off == reader->r_off)) { |
| mutex_unlock(&log->mutex); |
| goto start; |
| } |
| |
| /* get the size of the next entry */ |
| ret = get_user_hdr_len(reader->r_ver) + |
| get_entry_msg_len(log, reader->r_off); |
| if (count < ret) { |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| /* get exactly one entry from the log */ |
| ret = do_read_log_to_user(log, reader, buf, ret); |
| |
| out: |
| mutex_unlock(&log->mutex); |
| |
| return ret; |
| } |
| |
| /* |
| * get_next_entry - return the offset of the first valid entry at least 'len' |
| * bytes after 'off'. |
| * |
| * Caller must hold log->mutex. |
| */ |
| static size_t get_next_entry(struct logger_log *log, size_t off, size_t len) |
| { |
| size_t count = 0; |
| |
| do { |
| size_t nr = sizeof(struct logger_entry) + |
| get_entry_msg_len(log, off); |
| off = logger_offset(log, off + nr); |
| count += nr; |
| } while (count < len); |
| |
| return off; |
| } |
| |
| /* |
| * is_between - is a < c < b, accounting for wrapping of a, b, and c |
| * positions in the buffer |
| * |
| * That is, if a<b, check for c between a and b |
| * and if a>b, check for c outside (not between) a and b |
| * |
| * |------- a xxxxxxxx b --------| |
| * c^ |
| * |
| * |xxxxx b --------- a xxxxxxxxx| |
| * c^ |
| * or c^ |
| */ |
| static inline int is_between(size_t a, size_t b, size_t c) |
| { |
| if (a < b) { |
| /* is c between a and b? */ |
| if (a < c && c <= b) |
| return 1; |
| } else { |
| /* is c outside of b through a? */ |
| if (c <= b || a < c) |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * fix_up_readers - walk the list of all readers and "fix up" any who were |
| * lapped by the writer; also do the same for the default "start head". |
| * We do this by "pulling forward" the readers and start head to the first |
| * entry after the new write head. |
| * |
| * The caller needs to hold log->mutex. |
| */ |
| static void fix_up_readers(struct logger_log *log, size_t len) |
| { |
| size_t old = log->w_off; |
| size_t new = logger_offset(log, old + len); |
| struct logger_reader *reader; |
| |
| if (is_between(old, new, log->head)) |
| log->head = get_next_entry(log, log->head, len); |
| |
| list_for_each_entry(reader, &log->readers, list) |
| if (is_between(old, new, reader->r_off)) |
| reader->r_off = get_next_entry(log, reader->r_off, len); |
| } |
| |
| /* |
| * do_write_log - writes 'len' bytes from 'buf' to 'log' |
| * |
| * The caller needs to hold log->mutex. |
| */ |
| static void do_write_log(struct logger_log *log, const void *buf, size_t count) |
| { |
| size_t len; |
| |
| len = min(count, log->size - log->w_off); |
| memcpy(log->buffer + log->w_off, buf, len); |
| |
| if (count != len) |
| memcpy(log->buffer, buf + len, count - len); |
| |
| log->w_off = logger_offset(log, log->w_off + count); |
| |
| } |
| |
| /* |
| * do_write_log_user - writes 'len' bytes from the user-space buffer 'buf' to |
| * the log 'log' |
| * |
| * The caller needs to hold log->mutex. |
| * |
| * Returns 'count' on success, negative error code on failure. |
| */ |
| static ssize_t do_write_log_from_user(struct logger_log *log, |
| const void __user *buf, size_t count) |
| { |
| size_t len; |
| |
| len = min(count, log->size - log->w_off); |
| if (len && copy_from_user(log->buffer + log->w_off, buf, len)) |
| return -EFAULT; |
| |
| if (count != len) |
| if (copy_from_user(log->buffer, buf + len, count - len)) |
| /* |
| * Note that by not updating w_off, this abandons the |
| * portion of the new entry that *was* successfully |
| * copied, just above. This is intentional to avoid |
| * message corruption from missing fragments. |
| */ |
| return -EFAULT; |
| |
| log->w_off = logger_offset(log, log->w_off + count); |
| |
| return count; |
| } |
| |
| /* |
| * logger_aio_write - our write method, implementing support for write(), |
| * writev(), and aio_write(). Writes are our fast path, and we try to optimize |
| * them above all else. |
| */ |
| static ssize_t logger_aio_write(struct kiocb *iocb, const struct iovec *iov, |
| unsigned long nr_segs, loff_t ppos) |
| { |
| struct logger_log *log = file_get_log(iocb->ki_filp); |
| size_t orig = log->w_off; |
| struct logger_entry header; |
| struct timespec now; |
| ssize_t ret = 0; |
| |
| now = current_kernel_time(); |
| |
| header.pid = current->tgid; |
| header.tid = current->pid; |
| header.sec = now.tv_sec; |
| header.nsec = now.tv_nsec; |
| header.euid = current_euid(); |
| header.len = min_t(size_t, iocb->ki_left, LOGGER_ENTRY_MAX_PAYLOAD); |
| header.hdr_size = sizeof(struct logger_entry); |
| |
| /* null writes succeed, return zero */ |
| if (unlikely(!header.len)) |
| return 0; |
| |
| mutex_lock(&log->mutex); |
| |
| /* |
| * Fix up any readers, pulling them forward to the first readable |
| * entry after (what will be) the new write offset. We do this now |
| * because if we partially fail, we can end up with clobbered log |
| * entries that encroach on readable buffer. |
| */ |
| fix_up_readers(log, sizeof(struct logger_entry) + header.len); |
| |
| do_write_log(log, &header, sizeof(struct logger_entry)); |
| |
| while (nr_segs-- > 0) { |
| size_t len; |
| ssize_t nr; |
| |
| /* figure out how much of this vector we can keep */ |
| len = min_t(size_t, iov->iov_len, header.len - ret); |
| |
| /* write out this segment's payload */ |
| nr = do_write_log_from_user(log, iov->iov_base, len); |
| if (unlikely(nr < 0)) { |
| log->w_off = orig; |
| mutex_unlock(&log->mutex); |
| return nr; |
| } |
| |
| iov++; |
| ret += nr; |
| } |
| |
| mutex_unlock(&log->mutex); |
| |
| /* wake up any blocked readers */ |
| wake_up_interruptible(&log->wq); |
| |
| return ret; |
| } |
| |
| static struct logger_log *get_log_from_minor(int minor) |
| { |
| struct logger_log *log; |
| |
| list_for_each_entry(log, &log_list, logs) |
| if (log->misc.minor == minor) |
| return log; |
| return NULL; |
| } |
| |
| /* |
| * logger_open - the log's open() file operation |
| * |
| * Note how near a no-op this is in the write-only case. Keep it that way! |
| */ |
| static int logger_open(struct inode *inode, struct file *file) |
| { |
| struct logger_log *log; |
| int ret; |
| |
| ret = nonseekable_open(inode, file); |
| if (ret) |
| return ret; |
| |
| log = get_log_from_minor(MINOR(inode->i_rdev)); |
| if (!log) |
| return -ENODEV; |
| |
| if (file->f_mode & FMODE_READ) { |
| struct logger_reader *reader; |
| |
| reader = kmalloc(sizeof(struct logger_reader), GFP_KERNEL); |
| if (!reader) |
| return -ENOMEM; |
| |
| reader->log = log; |
| reader->r_ver = 1; |
| reader->r_all = in_egroup_p(inode->i_gid) || |
| capable(CAP_SYSLOG); |
| |
| INIT_LIST_HEAD(&reader->list); |
| |
| mutex_lock(&log->mutex); |
| reader->r_off = log->head; |
| list_add_tail(&reader->list, &log->readers); |
| mutex_unlock(&log->mutex); |
| |
| file->private_data = reader; |
| } else |
| file->private_data = log; |
| |
| return 0; |
| } |
| |
| /* |
| * logger_release - the log's release file operation |
| * |
| * Note this is a total no-op in the write-only case. Keep it that way! |
| */ |
| static int logger_release(struct inode *ignored, struct file *file) |
| { |
| if (file->f_mode & FMODE_READ) { |
| struct logger_reader *reader = file->private_data; |
| struct logger_log *log = reader->log; |
| |
| mutex_lock(&log->mutex); |
| list_del(&reader->list); |
| mutex_unlock(&log->mutex); |
| |
| kfree(reader); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * logger_poll - the log's poll file operation, for poll/select/epoll |
| * |
| * Note we always return POLLOUT, because you can always write() to the log. |
| * Note also that, strictly speaking, a return value of POLLIN does not |
| * guarantee that the log is readable without blocking, as there is a small |
| * chance that the writer can lap the reader in the interim between poll() |
| * returning and the read() request. |
| */ |
| static unsigned int logger_poll(struct file *file, poll_table *wait) |
| { |
| struct logger_reader *reader; |
| struct logger_log *log; |
| unsigned int ret = POLLOUT | POLLWRNORM; |
| |
| if (!(file->f_mode & FMODE_READ)) |
| return ret; |
| |
| reader = file->private_data; |
| log = reader->log; |
| |
| poll_wait(file, &log->wq, wait); |
| |
| mutex_lock(&log->mutex); |
| if (!reader->r_all) |
| reader->r_off = get_next_entry_by_uid(log, |
| reader->r_off, current_euid()); |
| |
| if (log->w_off != reader->r_off) |
| ret |= POLLIN | POLLRDNORM; |
| mutex_unlock(&log->mutex); |
| |
| return ret; |
| } |
| |
| static long logger_set_version(struct logger_reader *reader, void __user *arg) |
| { |
| int version; |
| if (copy_from_user(&version, arg, sizeof(int))) |
| return -EFAULT; |
| |
| if ((version < 1) || (version > 2)) |
| return -EINVAL; |
| |
| reader->r_ver = version; |
| return 0; |
| } |
| |
| static long logger_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
| { |
| struct logger_log *log = file_get_log(file); |
| struct logger_reader *reader; |
| long ret = -EINVAL; |
| void __user *argp = (void __user *) arg; |
| |
| mutex_lock(&log->mutex); |
| |
| switch (cmd) { |
| case LOGGER_GET_LOG_BUF_SIZE: |
| ret = log->size; |
| break; |
| case LOGGER_GET_LOG_LEN: |
| if (!(file->f_mode & FMODE_READ)) { |
| ret = -EBADF; |
| break; |
| } |
| reader = file->private_data; |
| if (log->w_off >= reader->r_off) |
| ret = log->w_off - reader->r_off; |
| else |
| ret = (log->size - reader->r_off) + log->w_off; |
| break; |
| case LOGGER_GET_NEXT_ENTRY_LEN: |
| if (!(file->f_mode & FMODE_READ)) { |
| ret = -EBADF; |
| break; |
| } |
| reader = file->private_data; |
| |
| if (!reader->r_all) |
| reader->r_off = get_next_entry_by_uid(log, |
| reader->r_off, current_euid()); |
| |
| if (log->w_off != reader->r_off) |
| ret = get_user_hdr_len(reader->r_ver) + |
| get_entry_msg_len(log, reader->r_off); |
| else |
| ret = 0; |
| break; |
| case LOGGER_FLUSH_LOG: |
| if (!(file->f_mode & FMODE_WRITE)) { |
| ret = -EBADF; |
| break; |
| } |
| if (!(in_egroup_p(file->f_dentry->d_inode->i_gid) || |
| capable(CAP_SYSLOG))) { |
| ret = -EPERM; |
| break; |
| } |
| list_for_each_entry(reader, &log->readers, list) |
| reader->r_off = log->w_off; |
| log->head = log->w_off; |
| ret = 0; |
| break; |
| case LOGGER_GET_VERSION: |
| if (!(file->f_mode & FMODE_READ)) { |
| ret = -EBADF; |
| break; |
| } |
| reader = file->private_data; |
| ret = reader->r_ver; |
| break; |
| case LOGGER_SET_VERSION: |
| if (!(file->f_mode & FMODE_READ)) { |
| ret = -EBADF; |
| break; |
| } |
| reader = file->private_data; |
| ret = logger_set_version(reader, argp); |
| break; |
| } |
| |
| mutex_unlock(&log->mutex); |
| |
| return ret; |
| } |
| |
| static const struct file_operations logger_fops = { |
| .owner = THIS_MODULE, |
| .read = logger_read, |
| .aio_write = logger_aio_write, |
| .poll = logger_poll, |
| .unlocked_ioctl = logger_ioctl, |
| .compat_ioctl = logger_ioctl, |
| .open = logger_open, |
| .release = logger_release, |
| }; |
| |
| /* |
| * Log size must must be a power of two, and greater than |
| * (LOGGER_ENTRY_MAX_PAYLOAD + sizeof(struct logger_entry)). |
| */ |
| static int __init create_log(char *log_name, int size) |
| { |
| int ret = 0; |
| struct logger_log *log; |
| unsigned char *buffer; |
| |
| buffer = vmalloc(size); |
| if (buffer == NULL) |
| return -ENOMEM; |
| |
| log = kzalloc(sizeof(struct logger_log), GFP_KERNEL); |
| if (log == NULL) { |
| ret = -ENOMEM; |
| goto out_free_buffer; |
| } |
| log->buffer = buffer; |
| |
| log->misc.minor = MISC_DYNAMIC_MINOR; |
| log->misc.name = kstrdup(log_name, GFP_KERNEL); |
| if (log->misc.name == NULL) { |
| ret = -ENOMEM; |
| goto out_free_log; |
| } |
| |
| log->misc.fops = &logger_fops; |
| log->misc.parent = NULL; |
| |
| init_waitqueue_head(&log->wq); |
| INIT_LIST_HEAD(&log->readers); |
| mutex_init(&log->mutex); |
| log->w_off = 0; |
| log->head = 0; |
| log->size = size; |
| |
| INIT_LIST_HEAD(&log->logs); |
| list_add_tail(&log->logs, &log_list); |
| |
| /* finally, initialize the misc device for this log */ |
| ret = misc_register(&log->misc); |
| if (unlikely(ret)) { |
| pr_err("failed to register misc device for log '%s'!\n", |
| log->misc.name); |
| goto out_free_log; |
| } |
| |
| pr_info("created %luK log '%s'\n", |
| (unsigned long) log->size >> 10, log->misc.name); |
| |
| return 0; |
| |
| out_free_log: |
| kfree(log); |
| |
| out_free_buffer: |
| vfree(buffer); |
| return ret; |
| } |
| |
| static int __init logger_init(void) |
| { |
| int ret; |
| |
| ret = create_log(LOGGER_LOG_MAIN, 256*1024); |
| if (unlikely(ret)) |
| goto out; |
| |
| ret = create_log(LOGGER_LOG_EVENTS, 256*1024); |
| if (unlikely(ret)) |
| goto out; |
| |
| ret = create_log(LOGGER_LOG_RADIO, 256*1024); |
| if (unlikely(ret)) |
| goto out; |
| |
| ret = create_log(LOGGER_LOG_SYSTEM, 256*1024); |
| if (unlikely(ret)) |
| goto out; |
| |
| out: |
| return ret; |
| } |
| |
| static void __exit logger_exit(void) |
| { |
| struct logger_log *current_log, *next_log; |
| |
| list_for_each_entry_safe(current_log, next_log, &log_list, logs) { |
| /* we have to delete all the entry inside log_list */ |
| misc_deregister(¤t_log->misc); |
| vfree(current_log->buffer); |
| kfree(current_log->misc.name); |
| list_del(¤t_log->logs); |
| kfree(current_log); |
| } |
| } |
| |
| |
| device_initcall(logger_init); |
| module_exit(logger_exit); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Robert Love, <rlove@google.com>"); |
| MODULE_DESCRIPTION("Android Logger"); |