+++ /dev/null
-/*
- * ring_buffer_abi.c
- *
- * Copyright (C) 2009-2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * Ring Buffer ABI operations.
- *
- * Dual LGPL v2.1/GPL v2 license.
- */
-
-#include "backend.h"
-#include "frontend.h"
-#include <lttng/ring-buffer-abi.h>
-
-static int put_ulong(unsigned long val, unsigned long arg)
-{
- return put_user(val, (unsigned long __user *)arg);
-}
-
-#ifdef CONFIG_COMPAT
-static int compat_put_ulong(compat_ulong_t val, unsigned long arg)
-{
- return put_user(val, (compat_ulong_t __user *)compat_ptr(arg));
-}
-#endif
-
-/**
- * lib_ring_buffer_open - ring buffer open file operation
- * @inode: opened inode
- * @file: opened file
- *
- * Open implementation. Makes sure only one open instance of a buffer is
- * done at a given moment.
- */
-int lib_ring_buffer_open(struct inode *inode, struct file *file)
-{
- struct lttng_ust_lib_ring_buffer *buf = inode->i_private;
- int ret;
-
- ret = lib_ring_buffer_open_read(buf);
- if (ret)
- return ret;
-
- file->private_data = buf;
- ret = nonseekable_open(inode, file);
- if (ret)
- goto release_read;
- return 0;
-
-release_read:
- lib_ring_buffer_release_read(buf);
- return ret;
-}
-
-/**
- * lib_ring_buffer_release - ring buffer release file operation
- * @inode: opened inode
- * @file: opened file
- *
- * Release implementation.
- */
-int lib_ring_buffer_release(struct inode *inode, struct file *file)
-{
- struct lttng_ust_lib_ring_buffer *buf = file->private_data;
-
- lib_ring_buffer_release_read(buf);
-
- return 0;
-}
-
-/**
- * lib_ring_buffer_poll - ring buffer poll file operation
- * @filp: the file
- * @wait: poll table
- *
- * Poll implementation.
- */
-unsigned int lib_ring_buffer_poll(struct file *filp, poll_table *wait)
-{
- unsigned int mask = 0;
- struct lttng_ust_lib_ring_buffer *buf = filp->private_data;
- struct channel *chan = buf->backend.chan;
- const struct lttng_ust_lib_ring_buffer_config *config = chan->backend.config;
- int finalized, disabled;
-
- if (filp->f_mode & FMODE_READ) {
- poll_wait_set_exclusive(wait);
- poll_wait(filp, &buf->read_wait, wait);
-
- finalized = lib_ring_buffer_is_finalized(config, buf);
- disabled = lib_ring_buffer_channel_is_disabled(chan);
-
- /*
- * lib_ring_buffer_is_finalized() contains a smp_rmb() ordering
- * finalized load before offsets loads.
- */
- WARN_ON(atomic_long_read(&buf->active_readers) != 1);
-retry:
- if (disabled)
- return POLLERR;
-
- if (subbuf_trunc(lib_ring_buffer_get_offset(config, buf), chan)
- - subbuf_trunc(lib_ring_buffer_get_consumed(config, buf), chan)
- == 0) {
- if (finalized)
- return POLLHUP;
- else {
- /*
- * The memory barriers
- * __wait_event()/wake_up_interruptible() take
- * care of "raw_spin_is_locked" memory ordering.
- */
- if (raw_spin_is_locked(&buf->raw_tick_nohz_spinlock))
- goto retry;
- else
- return 0;
- }
- } else {
- if (subbuf_trunc(lib_ring_buffer_get_offset(config, buf),
- chan)
- - subbuf_trunc(lib_ring_buffer_get_consumed(config, buf),
- chan)
- >= chan->backend.buf_size)
- return POLLPRI | POLLRDBAND;
- else
- return POLLIN | POLLRDNORM;
- }
- }
- return mask;
-}
-
-/**
- * lib_ring_buffer_ioctl - control ring buffer reader synchronization
- *
- * @filp: the file
- * @cmd: the command
- * @arg: command arg
- *
- * This ioctl implements commands necessary for producer/consumer
- * and flight recorder reader interaction :
- * RING_BUFFER_GET_NEXT_SUBBUF
- * Get the next sub-buffer that can be read. It never blocks.
- * RING_BUFFER_PUT_NEXT_SUBBUF
- * Release the currently read sub-buffer.
- * RING_BUFFER_GET_SUBBUF_SIZE
- * returns the size of the current sub-buffer.
- * RING_BUFFER_GET_MAX_SUBBUF_SIZE
- * returns the maximum size for sub-buffers.
- * RING_BUFFER_GET_NUM_SUBBUF
- * returns the number of reader-visible sub-buffers in the per cpu
- * channel (for mmap).
- * RING_BUFFER_GET_MMAP_READ_OFFSET
- * returns the offset of the subbuffer belonging to the reader.
- * Should only be used for mmap clients.
- */
-long lib_ring_buffer_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
-{
- struct lttng_ust_lib_ring_buffer *buf = filp->private_data;
- struct channel *chan = buf->backend.chan;
- const struct lttng_ust_lib_ring_buffer_config *config = chan->backend.config;
-
- if (lib_ring_buffer_channel_is_disabled(chan))
- return -EIO;
-
- switch (cmd) {
- case RING_BUFFER_SNAPSHOT:
- return lib_ring_buffer_snapshot(buf, &buf->cons_snapshot,
- &buf->prod_snapshot);
- case RING_BUFFER_SNAPSHOT_GET_CONSUMED:
- return put_ulong(buf->cons_snapshot, arg);
- case RING_BUFFER_SNAPSHOT_GET_PRODUCED:
- return put_ulong(buf->prod_snapshot, arg);
- case RING_BUFFER_GET_SUBBUF:
- {
- unsigned long uconsume;
- long ret;
-
- ret = get_user(uconsume, (unsigned long __user *) arg);
- if (ret)
- return ret; /* will return -EFAULT */
- ret = lib_ring_buffer_get_subbuf(buf, uconsume);
- if (!ret) {
- /* Set file position to zero at each successful "get" */
- filp->f_pos = 0;
- }
- return ret;
- }
- case RING_BUFFER_PUT_SUBBUF:
- lib_ring_buffer_put_subbuf(buf);
- return 0;
-
- case RING_BUFFER_GET_NEXT_SUBBUF:
- {
- long ret;
-
- ret = lib_ring_buffer_get_next_subbuf(buf);
- if (!ret) {
- /* Set file position to zero at each successful "get" */
- filp->f_pos = 0;
- }
- return ret;
- }
- case RING_BUFFER_PUT_NEXT_SUBBUF:
- lib_ring_buffer_put_next_subbuf(buf);
- return 0;
- case RING_BUFFER_GET_SUBBUF_SIZE:
- return put_ulong(lib_ring_buffer_get_read_data_size(config, buf),
- arg);
- case RING_BUFFER_GET_PADDED_SUBBUF_SIZE:
- {
- unsigned long size;
-
- size = lib_ring_buffer_get_read_data_size(config, buf);
- size = PAGE_ALIGN(size);
- return put_ulong(size, arg);
- }
- case RING_BUFFER_GET_MAX_SUBBUF_SIZE:
- return put_ulong(chan->backend.subbuf_size, arg);
- case RING_BUFFER_GET_MMAP_LEN:
- {
- unsigned long mmap_buf_len;
-
- if (config->output != RING_BUFFER_MMAP)
- return -EINVAL;
- mmap_buf_len = chan->backend.buf_size;
- if (chan->backend.extra_reader_sb)
- mmap_buf_len += chan->backend.subbuf_size;
- if (mmap_buf_len > INT_MAX)
- return -EFBIG;
- return put_ulong(mmap_buf_len, arg);
- }
- case RING_BUFFER_GET_MMAP_READ_OFFSET:
- {
- unsigned long sb_bindex;
-
- if (config->output != RING_BUFFER_MMAP)
- return -EINVAL;
- sb_bindex = subbuffer_id_get_index(config,
- buf->backend.buf_rsb.id);
- return put_ulong(buf->backend.array[sb_bindex]->mmap_offset,
- arg);
- }
- case RING_BUFFER_FLUSH:
- lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE, handle);
- return 0;
- default:
- return -ENOIOCTLCMD;
- }
-}
-
-#ifdef CONFIG_COMPAT
-long lib_ring_buffer_compat_ioctl(struct file *filp, unsigned int cmd,
- unsigned long arg)
-{
- struct lttng_ust_lib_ring_buffer *buf = filp->private_data;
- struct channel *chan = buf->backend.chan;
- const struct lttng_ust_lib_ring_buffer_config *config = chan->backend.config;
-
- if (lib_ring_buffer_channel_is_disabled(chan))
- return -EIO;
-
- switch (cmd) {
- case RING_BUFFER_SNAPSHOT:
- return lib_ring_buffer_snapshot(buf, &buf->cons_snapshot,
- &buf->prod_snapshot);
- case RING_BUFFER_SNAPSHOT_GET_CONSUMED:
- return compat_put_ulong(buf->cons_snapshot, arg);
- case RING_BUFFER_SNAPSHOT_GET_PRODUCED:
- return compat_put_ulong(buf->prod_snapshot, arg);
- case RING_BUFFER_GET_SUBBUF:
- {
- __u32 uconsume;
- unsigned long consume;
- long ret;
-
- ret = get_user(uconsume, (__u32 __user *) arg);
- if (ret)
- return ret; /* will return -EFAULT */
- consume = buf->cons_snapshot;
- consume &= ~0xFFFFFFFFL;
- consume |= uconsume;
- ret = lib_ring_buffer_get_subbuf(buf, consume);
- if (!ret) {
- /* Set file position to zero at each successful "get" */
- filp->f_pos = 0;
- }
- return ret;
- }
- case RING_BUFFER_PUT_SUBBUF:
- lib_ring_buffer_put_subbuf(buf);
- return 0;
-
- case RING_BUFFER_GET_NEXT_SUBBUF:
- {
- long ret;
-
- ret = lib_ring_buffer_get_next_subbuf(buf);
- if (!ret) {
- /* Set file position to zero at each successful "get" */
- filp->f_pos = 0;
- }
- return ret;
- }
- case RING_BUFFER_PUT_NEXT_SUBBUF:
- lib_ring_buffer_put_next_subbuf(buf);
- return 0;
- case RING_BUFFER_GET_SUBBUF_SIZE:
- {
- unsigned long data_size;
-
- data_size = lib_ring_buffer_get_read_data_size(config, buf);
- if (data_size > UINT_MAX)
- return -EFBIG;
- return put_ulong(data_size, arg);
- }
- case RING_BUFFER_GET_PADDED_SUBBUF_SIZE:
- {
- unsigned long size;
-
- size = lib_ring_buffer_get_read_data_size(config, buf);
- size = PAGE_ALIGN(size);
- if (size > UINT_MAX)
- return -EFBIG;
- return put_ulong(size, arg);
- }
- case RING_BUFFER_GET_MAX_SUBBUF_SIZE:
- if (chan->backend.subbuf_size > UINT_MAX)
- return -EFBIG;
- return put_ulong(chan->backend.subbuf_size, arg);
- case RING_BUFFER_GET_MMAP_LEN:
- {
- unsigned long mmap_buf_len;
-
- if (config->output != RING_BUFFER_MMAP)
- return -EINVAL;
- mmap_buf_len = chan->backend.buf_size;
- if (chan->backend.extra_reader_sb)
- mmap_buf_len += chan->backend.subbuf_size;
- if (mmap_buf_len > UINT_MAX)
- return -EFBIG;
- return put_ulong(mmap_buf_len, arg);
- }
- case RING_BUFFER_GET_MMAP_READ_OFFSET:
- {
- unsigned long sb_bindex, read_offset;
-
- if (config->output != RING_BUFFER_MMAP)
- return -EINVAL;
- sb_bindex = subbuffer_id_get_index(config,
- buf->backend.buf_rsb.id);
- read_offset = buf->backend.array[sb_bindex]->mmap_offset;
- if (read_offset > UINT_MAX)
- return -EINVAL;
- return put_ulong(read_offset, arg);
- }
- case RING_BUFFER_FLUSH:
- lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE, handle);
- return 0;
- default:
- return -ENOIOCTLCMD;
- }
-}
-#endif
-
-const struct file_operations lib_ring_buffer_file_operations = {
- .open = lib_ring_buffer_open,
- .release = lib_ring_buffer_release,
- .poll = lib_ring_buffer_poll,
- .splice_read = lib_ring_buffer_splice_read,
- .mmap = lib_ring_buffer_mmap,
- .unlocked_ioctl = lib_ring_buffer_ioctl,
- .llseek = lib_ring_buffer_no_llseek,
-#ifdef CONFIG_COMPAT
- .compat_ioctl = lib_ring_buffer_compat_ioctl,
-#endif
-};
projects / lttng-ust.git / commitdiff
