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Diffstat (limited to 'drivers/staging/android/logger.c')
-rw-r--r--drivers/staging/android/logger.c192
1 files changed, 166 insertions, 26 deletions
diff --git a/drivers/staging/android/logger.c b/drivers/staging/android/logger.c
index 4a3ce20..54481b2 100644
--- a/drivers/staging/android/logger.c
+++ b/drivers/staging/android/logger.c
@@ -58,6 +58,8 @@ 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 */
+ bool r_all; /* reader can read all entries */
+ int r_ver; /* reader ABI version */
};
/* logger_offset - returns index 'n' into the log via (optimized) modulus */
@@ -87,25 +89,71 @@ static inline struct logger_log *file_get_log(struct file *file)
}
/*
- * get_entry_len - Grabs the length of the payload of the next entry starting
- * from 'off'.
+ * 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'.
*
* Caller needs to hold log->mutex.
*/
-static __u32 get_entry_len(struct logger_log *log, size_t off)
+static __u32 get_entry_msg_len(struct logger_log *log, size_t off)
{
- __u16 val;
+ struct logger_entry scratch;
+ struct logger_entry *entry;
- 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);
+ 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 sizeof(struct logger_entry) + val;
+ return copy_to_user(buf, hdr, hdr_len);
}
/*
@@ -119,15 +167,30 @@ static ssize_t do_read_log_to_user(struct logger_log *log,
char __user *buf,
size_t count)
{
+ struct logger_entry scratch;
+ struct logger_entry *entry;
size_t len;
+ size_t msg_start;
/*
- * 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
+ * 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(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 - reader->r_off);
- if (copy_to_user(buf, log->buffer + reader->r_off, len))
+ len = min(count, log->size - msg_start);
+ if (copy_to_user(buf, log->buffer + msg_start, len))
return -EFAULT;
/*
@@ -138,9 +201,34 @@ static ssize_t do_read_log_to_user(struct logger_log *log,
if (copy_to_user(buf + len, log->buffer, count - len))
return -EFAULT;
- reader->r_off = logger_offset(reader->r_off + count);
+ reader->r_off = logger_offset(reader->r_off +
+ sizeof(struct logger_entry) + count);
- return 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, uid_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 (entry->euid == euid)
+ return off;
+
+ next_len = sizeof(struct logger_entry) + entry->len;
+ off = logger_offset(off + next_len);
+ }
+
+ return off;
}
/*
@@ -152,7 +240,7 @@ static ssize_t do_read_log_to_user(struct logger_log *log,
* - 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
+ * 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,
@@ -192,6 +280,10 @@ start:
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);
@@ -199,7 +291,8 @@ start:
}
/* get the size of the next entry */
- ret = get_entry_len(log, reader->r_off);
+ ret = get_user_hdr_len(reader->r_ver) +
+ get_entry_msg_len(log, reader->r_off);
if (count < ret) {
ret = -EINVAL;
goto out;
@@ -225,7 +318,8 @@ 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);
+ size_t nr = sizeof(struct logger_entry) +
+ get_entry_msg_len(log, off);
off = logger_offset(off + nr);
count += nr;
} while (count < len);
@@ -351,7 +445,9 @@ ssize_t logger_aio_write(struct kiocb *iocb, const struct iovec *iov,
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))
@@ -424,6 +520,10 @@ static int logger_open(struct inode *inode, struct file *file)
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);
@@ -485,6 +585,10 @@ static unsigned int logger_poll(struct file *file, poll_table *wait)
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);
@@ -492,11 +596,25 @@ static unsigned int logger_poll(struct file *file, poll_table *wait)
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 = -ENOTTY;
+ long ret = -EINVAL;
+ void __user *argp = (void __user *) arg;
mutex_lock(&log->mutex);
@@ -521,8 +639,14 @@ static long logger_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
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_entry_len(log, reader->r_off);
+ ret = get_user_hdr_len(reader->r_ver) +
+ get_entry_msg_len(log, reader->r_off);
else
ret = 0;
break;
@@ -536,6 +660,22 @@ static long logger_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
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);
@@ -556,8 +696,8 @@ static const struct file_operations logger_fops = {
/*
* 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.
+ * must be a power of two, and greater than
+ * (LOGGER_ENTRY_MAX_PAYLOAD + sizeof(struct logger_entry)).
*/
#define DEFINE_LOGGER_DEVICE(VAR, NAME, SIZE) \
static unsigned char _buf_ ## VAR[SIZE]; \
@@ -579,7 +719,7 @@ static struct logger_log VAR = { \
DEFINE_LOGGER_DEVICE(log_main, LOGGER_LOG_MAIN, 2048*1024)
DEFINE_LOGGER_DEVICE(log_events, LOGGER_LOG_EVENTS, 256*1024)
-DEFINE_LOGGER_DEVICE(log_radio, LOGGER_LOG_RADIO, 512*1024)
+DEFINE_LOGGER_DEVICE(log_radio, LOGGER_LOG_RADIO, 1024*1024)
DEFINE_LOGGER_DEVICE(log_system, LOGGER_LOG_SYSTEM, 256*1024)
DEFINE_LOGGER_DEVICE(log_sf, LOGGER_LOG_SF, 256*1024)