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-rw-r--r--drivers/android/logger.c607
1 files changed, 0 insertions, 607 deletions
diff --git a/drivers/android/logger.c b/drivers/android/logger.c
deleted file mode 100644
index 05dac301c90..00000000000
--- a/drivers/android/logger.c
+++ /dev/null
@@ -1,607 +0,0 @@
-/*
- * drivers/android/logger.c
- *
- * Android 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.
- */
-
-#include <linux/module.h>
-#include <linux/fs.h>
-#include <linux/miscdevice.h>
-#include <linux/uaccess.h>
-#include <linux/poll.h>
-#include <linux/time.h>
-#include <linux/logger.h>
-
-#include <asm/ioctls.h>
-
-/*
- * struct logger_log - represents a specific log, such as 'main' or 'radio'
- *
- * 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; /* the ring buffer itself */
- struct miscdevice misc; /* misc device representing the log */
- wait_queue_head_t wq; /* wait queue for readers */
- struct list_head readers; /* this log's readers */
- struct mutex mutex; /* mutex protecting buffer */
- size_t w_off; /* current write head offset */
- size_t head; /* new readers start here */
- size_t size; /* size of the log */
-};
-
-/*
- * struct logger_reader - a logging device open for reading
- *
- * 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; /* associated log */
- struct list_head list; /* entry in logger_log's list */
- size_t r_off; /* current read head offset */
-};
-
-/* logger_offset - returns index 'n' into the log via (optimized) modulus */
-#define logger_offset(n) ((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_len - Grabs the length of the payload of the next entry starting
- * from 'off'.
- *
- * Caller needs to hold log->mutex.
- */
-static __u32 get_entry_len(struct logger_log *log, size_t off)
-{
- __u16 val;
-
- switch (log->size - off) {
- case 1:
- memcpy(&val, log->buffer + off, 1);
- memcpy(((char *) &val) + 1, log->buffer, 1);
- break;
- default:
- memcpy(&val, log->buffer + off, 2);
- }
-
- return sizeof(struct logger_entry) + val;
-}
-
-/*
- * 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)
-{
- size_t len;
-
- /*
- * We read from the log in two disjoint operations. First, we read from
- * the current read head offset up to 'count' bytes or to the end of
- * the log, whichever comes first.
- */
- len = min(count, log->size - reader->r_off);
- if (copy_to_user(buf, log->buffer + reader->r_off, 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(reader->r_off + count);
-
- return count;
-}
-
-/*
- * 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
- *
- * Optimal read size is LOGGER_ENTRY_MAX_LEN. 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) {
- prepare_to_wait(&log->wq, &wait, TASK_INTERRUPTIBLE);
-
- mutex_lock(&log->mutex);
- 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);
-
- /* 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_entry_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 = get_entry_len(log, off);
- off = logger_offset(off + nr);
- count += nr;
- } while (count < len);
-
- return off;
-}
-
-/*
- * clock_interval - is a < c < b in mod-space? Put another way, does the line
- * from a to b cross c?
- */
-static inline int clock_interval(size_t a, size_t b, size_t c)
-{
- if (b < a) {
- if (a < c || b >= c)
- return 1;
- } else {
- if (a < c && b >= 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(old + len);
- struct logger_reader *reader;
-
- if (clock_interval(old, new, log->head))
- log->head = get_next_entry(log, log->head, len);
-
- list_for_each_entry(reader, &log->readers, list)
- if (clock_interval(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->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))
- return -EFAULT;
-
- log->w_off = logger_offset(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.
- */
-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.len = min_t(size_t, iocb->ki_left, LOGGER_ENTRY_MAX_PAYLOAD);
-
- /* 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);
-
-/*
- * 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;
- 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;
- list_del(&reader->list);
- 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 (log->w_off != reader->r_off)
- ret |= POLLIN | POLLRDNORM;
- mutex_unlock(&log->mutex);
-
- return ret;
-}
-
-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 = -ENOTTY;
-
- 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 (log->w_off != reader->r_off)
- ret = get_entry_len(log, reader->r_off);
- else
- ret = 0;
- break;
- case LOGGER_FLUSH_LOG:
- if (!(file->f_mode & FMODE_WRITE)) {
- ret = -EBADF;
- break;
- }
- list_for_each_entry(reader, &log->readers, list)
- reader->r_off = log->w_off;
- log->head = log->w_off;
- ret = 0;
- break;
- }
-
- mutex_unlock(&log->mutex);
-
- return ret;
-}
-
-static 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,
-};
-
-/*
- * Defines a log structure with name 'NAME' and a size of 'SIZE' bytes, which
- * must be a power of two, greater than LOGGER_ENTRY_MAX_LEN, and less than
- * LONG_MAX minus LOGGER_ENTRY_MAX_LEN.
- */
-#define DEFINE_LOGGER_DEVICE(VAR, NAME, SIZE) \
-static unsigned char _buf_ ## VAR[SIZE]; \
-static struct logger_log VAR = { \
- .buffer = _buf_ ## VAR, \
- .misc = { \
- .minor = MISC_DYNAMIC_MINOR, \
- .name = NAME, \
- .fops = &logger_fops, \
- .parent = NULL, \
- }, \
- .wq = __WAIT_QUEUE_HEAD_INITIALIZER(VAR .wq), \
- .readers = LIST_HEAD_INIT(VAR .readers), \
- .mutex = __MUTEX_INITIALIZER(VAR .mutex), \
- .w_off = 0, \
- .head = 0, \
- .size = SIZE, \
-};
-
-DEFINE_LOGGER_DEVICE(log_main, LOGGER_LOG_MAIN, 64*1024)
-DEFINE_LOGGER_DEVICE(log_events, LOGGER_LOG_EVENTS, 256*1024)
-DEFINE_LOGGER_DEVICE(log_radio, LOGGER_LOG_RADIO, 64*1024)
-
-static struct logger_log * get_log_from_minor(int minor)
-{
- if (log_main.misc.minor == minor)
- return &log_main;
- if (log_events.misc.minor == minor)
- return &log_events;
- if (log_radio.misc.minor == minor)
- return &log_radio;
- return NULL;
-}
-
-static int __init init_log(struct logger_log *log)
-{
- int ret;
-
- ret = misc_register(&log->misc);
- if (unlikely(ret)) {
- printk(KERN_ERR "logger: failed to register misc "
- "device for log '%s'!\n", log->misc.name);
- return ret;
- }
-
- printk(KERN_INFO "logger: created %luK log '%s'\n",
- (unsigned long) log->size >> 10, log->misc.name);
-
- return 0;
-}
-
-static int __init logger_init(void)
-{
- int ret;
-
- ret = init_log(&log_main);
- if (unlikely(ret))
- goto out;
-
- ret = init_log(&log_events);
- if (unlikely(ret))
- goto out;
-
- ret = init_log(&log_radio);
- if (unlikely(ret))
- goto out;
-
-out:
- return ret;
-}
-device_initcall(logger_init);