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1150 lines
26 KiB
1150 lines
26 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* linux/fs/seq_file.c |
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* |
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* helper functions for making synthetic files from sequences of records. |
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* initial implementation -- AV, Oct 2001. |
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*/ |
|
|
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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|
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#include <linux/cache.h> |
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#include <linux/fs.h> |
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#include <linux/export.h> |
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#include <linux/seq_file.h> |
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#include <linux/vmalloc.h> |
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#include <linux/slab.h> |
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#include <linux/cred.h> |
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#include <linux/mm.h> |
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#include <linux/printk.h> |
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#include <linux/string_helpers.h> |
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#include <linux/uio.h> |
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|
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#include <linux/uaccess.h> |
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#include <asm/page.h> |
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|
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static struct kmem_cache *seq_file_cache __ro_after_init; |
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|
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static void seq_set_overflow(struct seq_file *m) |
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{ |
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m->count = m->size; |
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} |
|
|
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static void *seq_buf_alloc(unsigned long size) |
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{ |
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if (unlikely(size > MAX_RW_COUNT)) |
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return NULL; |
|
|
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return kvmalloc(size, GFP_KERNEL_ACCOUNT); |
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} |
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|
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/** |
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* seq_open - initialize sequential file |
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* @file: file we initialize |
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* @op: method table describing the sequence |
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* |
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* seq_open() sets @file, associating it with a sequence described |
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* by @op. @op->start() sets the iterator up and returns the first |
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* element of sequence. @op->stop() shuts it down. @op->next() |
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* returns the next element of sequence. @op->show() prints element |
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* into the buffer. In case of error ->start() and ->next() return |
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* ERR_PTR(error). In the end of sequence they return %NULL. ->show() |
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* returns 0 in case of success and negative number in case of error. |
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* Returning SEQ_SKIP means "discard this element and move on". |
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* Note: seq_open() will allocate a struct seq_file and store its |
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* pointer in @file->private_data. This pointer should not be modified. |
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*/ |
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int seq_open(struct file *file, const struct seq_operations *op) |
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{ |
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struct seq_file *p; |
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|
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WARN_ON(file->private_data); |
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|
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p = kmem_cache_zalloc(seq_file_cache, GFP_KERNEL); |
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if (!p) |
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return -ENOMEM; |
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|
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file->private_data = p; |
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|
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mutex_init(&p->lock); |
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p->op = op; |
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|
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// No refcounting: the lifetime of 'p' is constrained |
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// to the lifetime of the file. |
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p->file = file; |
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|
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/* |
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* seq_files support lseek() and pread(). They do not implement |
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* write() at all, but we clear FMODE_PWRITE here for historical |
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* reasons. |
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* |
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* If a client of seq_files a) implements file.write() and b) wishes to |
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* support pwrite() then that client will need to implement its own |
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* file.open() which calls seq_open() and then sets FMODE_PWRITE. |
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*/ |
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file->f_mode &= ~FMODE_PWRITE; |
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return 0; |
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} |
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EXPORT_SYMBOL(seq_open); |
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|
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static int traverse(struct seq_file *m, loff_t offset) |
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{ |
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loff_t pos = 0; |
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int error = 0; |
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void *p; |
|
|
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m->index = 0; |
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m->count = m->from = 0; |
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if (!offset) |
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return 0; |
|
|
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if (!m->buf) { |
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m->buf = seq_buf_alloc(m->size = PAGE_SIZE); |
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if (!m->buf) |
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return -ENOMEM; |
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} |
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p = m->op->start(m, &m->index); |
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while (p) { |
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error = PTR_ERR(p); |
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if (IS_ERR(p)) |
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break; |
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error = m->op->show(m, p); |
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if (error < 0) |
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break; |
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if (unlikely(error)) { |
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error = 0; |
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m->count = 0; |
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} |
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if (seq_has_overflowed(m)) |
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goto Eoverflow; |
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p = m->op->next(m, p, &m->index); |
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if (pos + m->count > offset) { |
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m->from = offset - pos; |
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m->count -= m->from; |
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break; |
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} |
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pos += m->count; |
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m->count = 0; |
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if (pos == offset) |
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break; |
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} |
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m->op->stop(m, p); |
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return error; |
|
|
|
Eoverflow: |
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m->op->stop(m, p); |
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kvfree(m->buf); |
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m->count = 0; |
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m->buf = seq_buf_alloc(m->size <<= 1); |
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return !m->buf ? -ENOMEM : -EAGAIN; |
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} |
|
|
|
/** |
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* seq_read - ->read() method for sequential files. |
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* @file: the file to read from |
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* @buf: the buffer to read to |
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* @size: the maximum number of bytes to read |
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* @ppos: the current position in the file |
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* |
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* Ready-made ->f_op->read() |
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*/ |
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ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) |
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{ |
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struct iovec iov = { .iov_base = buf, .iov_len = size}; |
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struct kiocb kiocb; |
|
struct iov_iter iter; |
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ssize_t ret; |
|
|
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init_sync_kiocb(&kiocb, file); |
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iov_iter_init(&iter, READ, &iov, 1, size); |
|
|
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kiocb.ki_pos = *ppos; |
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ret = seq_read_iter(&kiocb, &iter); |
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*ppos = kiocb.ki_pos; |
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return ret; |
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} |
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EXPORT_SYMBOL(seq_read); |
|
|
|
/* |
|
* Ready-made ->f_op->read_iter() |
|
*/ |
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ssize_t seq_read_iter(struct kiocb *iocb, struct iov_iter *iter) |
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{ |
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struct seq_file *m = iocb->ki_filp->private_data; |
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size_t copied = 0; |
|
size_t n; |
|
void *p; |
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int err = 0; |
|
|
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if (!iov_iter_count(iter)) |
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return 0; |
|
|
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mutex_lock(&m->lock); |
|
|
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/* |
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* if request is to read from zero offset, reset iterator to first |
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* record as it might have been already advanced by previous requests |
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*/ |
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if (iocb->ki_pos == 0) { |
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m->index = 0; |
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m->count = 0; |
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} |
|
|
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/* Don't assume ki_pos is where we left it */ |
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if (unlikely(iocb->ki_pos != m->read_pos)) { |
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while ((err = traverse(m, iocb->ki_pos)) == -EAGAIN) |
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; |
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if (err) { |
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/* With prejudice... */ |
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m->read_pos = 0; |
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m->index = 0; |
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m->count = 0; |
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goto Done; |
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} else { |
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m->read_pos = iocb->ki_pos; |
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} |
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} |
|
|
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/* grab buffer if we didn't have one */ |
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if (!m->buf) { |
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m->buf = seq_buf_alloc(m->size = PAGE_SIZE); |
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if (!m->buf) |
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goto Enomem; |
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} |
|
// something left in the buffer - copy it out first |
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if (m->count) { |
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n = copy_to_iter(m->buf + m->from, m->count, iter); |
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m->count -= n; |
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m->from += n; |
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copied += n; |
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if (m->count) // hadn't managed to copy everything |
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goto Done; |
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} |
|
// get a non-empty record in the buffer |
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m->from = 0; |
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p = m->op->start(m, &m->index); |
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while (1) { |
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err = PTR_ERR(p); |
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if (!p || IS_ERR(p)) // EOF or an error |
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break; |
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err = m->op->show(m, p); |
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if (err < 0) // hard error |
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break; |
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if (unlikely(err)) // ->show() says "skip it" |
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m->count = 0; |
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if (unlikely(!m->count)) { // empty record |
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p = m->op->next(m, p, &m->index); |
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continue; |
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} |
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if (!seq_has_overflowed(m)) // got it |
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goto Fill; |
|
// need a bigger buffer |
|
m->op->stop(m, p); |
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kvfree(m->buf); |
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m->count = 0; |
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m->buf = seq_buf_alloc(m->size <<= 1); |
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if (!m->buf) |
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goto Enomem; |
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p = m->op->start(m, &m->index); |
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} |
|
// EOF or an error |
|
m->op->stop(m, p); |
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m->count = 0; |
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goto Done; |
|
Fill: |
|
// one non-empty record is in the buffer; if they want more, |
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// try to fit more in, but in any case we need to advance |
|
// the iterator once for every record shown. |
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while (1) { |
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size_t offs = m->count; |
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loff_t pos = m->index; |
|
|
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p = m->op->next(m, p, &m->index); |
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if (pos == m->index) { |
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pr_info_ratelimited("buggy .next function %ps did not update position index\n", |
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m->op->next); |
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m->index++; |
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} |
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if (!p || IS_ERR(p)) // no next record for us |
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break; |
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if (m->count >= iov_iter_count(iter)) |
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break; |
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err = m->op->show(m, p); |
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if (err > 0) { // ->show() says "skip it" |
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m->count = offs; |
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} else if (err || seq_has_overflowed(m)) { |
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m->count = offs; |
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break; |
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} |
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} |
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m->op->stop(m, p); |
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n = copy_to_iter(m->buf, m->count, iter); |
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copied += n; |
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m->count -= n; |
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m->from = n; |
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Done: |
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if (unlikely(!copied)) { |
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copied = m->count ? -EFAULT : err; |
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} else { |
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iocb->ki_pos += copied; |
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m->read_pos += copied; |
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} |
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mutex_unlock(&m->lock); |
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return copied; |
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Enomem: |
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err = -ENOMEM; |
|
goto Done; |
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} |
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EXPORT_SYMBOL(seq_read_iter); |
|
|
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/** |
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* seq_lseek - ->llseek() method for sequential files. |
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* @file: the file in question |
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* @offset: new position |
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* @whence: 0 for absolute, 1 for relative position |
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* |
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* Ready-made ->f_op->llseek() |
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*/ |
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loff_t seq_lseek(struct file *file, loff_t offset, int whence) |
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{ |
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struct seq_file *m = file->private_data; |
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loff_t retval = -EINVAL; |
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|
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mutex_lock(&m->lock); |
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switch (whence) { |
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case SEEK_CUR: |
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offset += file->f_pos; |
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fallthrough; |
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case SEEK_SET: |
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if (offset < 0) |
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break; |
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retval = offset; |
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if (offset != m->read_pos) { |
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while ((retval = traverse(m, offset)) == -EAGAIN) |
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; |
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if (retval) { |
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/* with extreme prejudice... */ |
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file->f_pos = 0; |
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m->read_pos = 0; |
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m->index = 0; |
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m->count = 0; |
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} else { |
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m->read_pos = offset; |
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retval = file->f_pos = offset; |
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} |
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} else { |
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file->f_pos = offset; |
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} |
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} |
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mutex_unlock(&m->lock); |
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return retval; |
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} |
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EXPORT_SYMBOL(seq_lseek); |
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|
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/** |
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* seq_release - free the structures associated with sequential file. |
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* @file: file in question |
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* @inode: its inode |
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* |
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* Frees the structures associated with sequential file; can be used |
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* as ->f_op->release() if you don't have private data to destroy. |
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*/ |
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int seq_release(struct inode *inode, struct file *file) |
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{ |
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struct seq_file *m = file->private_data; |
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kvfree(m->buf); |
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kmem_cache_free(seq_file_cache, m); |
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return 0; |
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} |
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EXPORT_SYMBOL(seq_release); |
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|
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/** |
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* seq_escape_mem - print data into buffer, escaping some characters |
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* @m: target buffer |
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* @src: source buffer |
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* @len: size of source buffer |
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* @flags: flags to pass to string_escape_mem() |
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* @esc: set of characters that need escaping |
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* |
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* Puts data into buffer, replacing each occurrence of character from |
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* given class (defined by @flags and @esc) with printable escaped sequence. |
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* |
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* Use seq_has_overflowed() to check for errors. |
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*/ |
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void seq_escape_mem(struct seq_file *m, const char *src, size_t len, |
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unsigned int flags, const char *esc) |
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{ |
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char *buf; |
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size_t size = seq_get_buf(m, &buf); |
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int ret; |
|
|
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ret = string_escape_mem(src, len, buf, size, flags, esc); |
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seq_commit(m, ret < size ? ret : -1); |
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} |
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EXPORT_SYMBOL(seq_escape_mem); |
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|
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void seq_vprintf(struct seq_file *m, const char *f, va_list args) |
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{ |
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int len; |
|
|
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if (m->count < m->size) { |
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len = vsnprintf(m->buf + m->count, m->size - m->count, f, args); |
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if (m->count + len < m->size) { |
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m->count += len; |
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return; |
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} |
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} |
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seq_set_overflow(m); |
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} |
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EXPORT_SYMBOL(seq_vprintf); |
|
|
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void seq_printf(struct seq_file *m, const char *f, ...) |
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{ |
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va_list args; |
|
|
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va_start(args, f); |
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seq_vprintf(m, f, args); |
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va_end(args); |
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} |
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EXPORT_SYMBOL(seq_printf); |
|
|
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#ifdef CONFIG_BINARY_PRINTF |
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void seq_bprintf(struct seq_file *m, const char *f, const u32 *binary) |
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{ |
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int len; |
|
|
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if (m->count < m->size) { |
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len = bstr_printf(m->buf + m->count, m->size - m->count, f, |
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binary); |
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if (m->count + len < m->size) { |
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m->count += len; |
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return; |
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} |
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} |
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seq_set_overflow(m); |
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} |
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EXPORT_SYMBOL(seq_bprintf); |
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#endif /* CONFIG_BINARY_PRINTF */ |
|
|
|
/** |
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* mangle_path - mangle and copy path to buffer beginning |
|
* @s: buffer start |
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* @p: beginning of path in above buffer |
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* @esc: set of characters that need escaping |
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* |
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* Copy the path from @p to @s, replacing each occurrence of character from |
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* @esc with usual octal escape. |
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* Returns pointer past last written character in @s, or NULL in case of |
|
* failure. |
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*/ |
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char *mangle_path(char *s, const char *p, const char *esc) |
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{ |
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while (s <= p) { |
|
char c = *p++; |
|
if (!c) { |
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return s; |
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} else if (!strchr(esc, c)) { |
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*s++ = c; |
|
} else if (s + 4 > p) { |
|
break; |
|
} else { |
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*s++ = '\\'; |
|
*s++ = '0' + ((c & 0300) >> 6); |
|
*s++ = '0' + ((c & 070) >> 3); |
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*s++ = '0' + (c & 07); |
|
} |
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} |
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return NULL; |
|
} |
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EXPORT_SYMBOL(mangle_path); |
|
|
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/** |
|
* seq_path - seq_file interface to print a pathname |
|
* @m: the seq_file handle |
|
* @path: the struct path to print |
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* @esc: set of characters to escape in the output |
|
* |
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* return the absolute path of 'path', as represented by the |
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* dentry / mnt pair in the path parameter. |
|
*/ |
|
int seq_path(struct seq_file *m, const struct path *path, const char *esc) |
|
{ |
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char *buf; |
|
size_t size = seq_get_buf(m, &buf); |
|
int res = -1; |
|
|
|
if (size) { |
|
char *p = d_path(path, buf, size); |
|
if (!IS_ERR(p)) { |
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char *end = mangle_path(buf, p, esc); |
|
if (end) |
|
res = end - buf; |
|
} |
|
} |
|
seq_commit(m, res); |
|
|
|
return res; |
|
} |
|
EXPORT_SYMBOL(seq_path); |
|
|
|
/** |
|
* seq_file_path - seq_file interface to print a pathname of a file |
|
* @m: the seq_file handle |
|
* @file: the struct file to print |
|
* @esc: set of characters to escape in the output |
|
* |
|
* return the absolute path to the file. |
|
*/ |
|
int seq_file_path(struct seq_file *m, struct file *file, const char *esc) |
|
{ |
|
return seq_path(m, &file->f_path, esc); |
|
} |
|
EXPORT_SYMBOL(seq_file_path); |
|
|
|
/* |
|
* Same as seq_path, but relative to supplied root. |
|
*/ |
|
int seq_path_root(struct seq_file *m, const struct path *path, |
|
const struct path *root, const char *esc) |
|
{ |
|
char *buf; |
|
size_t size = seq_get_buf(m, &buf); |
|
int res = -ENAMETOOLONG; |
|
|
|
if (size) { |
|
char *p; |
|
|
|
p = __d_path(path, root, buf, size); |
|
if (!p) |
|
return SEQ_SKIP; |
|
res = PTR_ERR(p); |
|
if (!IS_ERR(p)) { |
|
char *end = mangle_path(buf, p, esc); |
|
if (end) |
|
res = end - buf; |
|
else |
|
res = -ENAMETOOLONG; |
|
} |
|
} |
|
seq_commit(m, res); |
|
|
|
return res < 0 && res != -ENAMETOOLONG ? res : 0; |
|
} |
|
|
|
/* |
|
* returns the path of the 'dentry' from the root of its filesystem. |
|
*/ |
|
int seq_dentry(struct seq_file *m, struct dentry *dentry, const char *esc) |
|
{ |
|
char *buf; |
|
size_t size = seq_get_buf(m, &buf); |
|
int res = -1; |
|
|
|
if (size) { |
|
char *p = dentry_path(dentry, buf, size); |
|
if (!IS_ERR(p)) { |
|
char *end = mangle_path(buf, p, esc); |
|
if (end) |
|
res = end - buf; |
|
} |
|
} |
|
seq_commit(m, res); |
|
|
|
return res; |
|
} |
|
EXPORT_SYMBOL(seq_dentry); |
|
|
|
void *single_start(struct seq_file *p, loff_t *pos) |
|
{ |
|
return *pos ? NULL : SEQ_START_TOKEN; |
|
} |
|
|
|
static void *single_next(struct seq_file *p, void *v, loff_t *pos) |
|
{ |
|
++*pos; |
|
return NULL; |
|
} |
|
|
|
static void single_stop(struct seq_file *p, void *v) |
|
{ |
|
} |
|
|
|
int single_open(struct file *file, int (*show)(struct seq_file *, void *), |
|
void *data) |
|
{ |
|
struct seq_operations *op = kmalloc(sizeof(*op), GFP_KERNEL_ACCOUNT); |
|
int res = -ENOMEM; |
|
|
|
if (op) { |
|
op->start = single_start; |
|
op->next = single_next; |
|
op->stop = single_stop; |
|
op->show = show; |
|
res = seq_open(file, op); |
|
if (!res) |
|
((struct seq_file *)file->private_data)->private = data; |
|
else |
|
kfree(op); |
|
} |
|
return res; |
|
} |
|
EXPORT_SYMBOL(single_open); |
|
|
|
int single_open_size(struct file *file, int (*show)(struct seq_file *, void *), |
|
void *data, size_t size) |
|
{ |
|
char *buf = seq_buf_alloc(size); |
|
int ret; |
|
if (!buf) |
|
return -ENOMEM; |
|
ret = single_open(file, show, data); |
|
if (ret) { |
|
kvfree(buf); |
|
return ret; |
|
} |
|
((struct seq_file *)file->private_data)->buf = buf; |
|
((struct seq_file *)file->private_data)->size = size; |
|
return 0; |
|
} |
|
EXPORT_SYMBOL(single_open_size); |
|
|
|
int single_release(struct inode *inode, struct file *file) |
|
{ |
|
const struct seq_operations *op = ((struct seq_file *)file->private_data)->op; |
|
int res = seq_release(inode, file); |
|
kfree(op); |
|
return res; |
|
} |
|
EXPORT_SYMBOL(single_release); |
|
|
|
int seq_release_private(struct inode *inode, struct file *file) |
|
{ |
|
struct seq_file *seq = file->private_data; |
|
|
|
kfree(seq->private); |
|
seq->private = NULL; |
|
return seq_release(inode, file); |
|
} |
|
EXPORT_SYMBOL(seq_release_private); |
|
|
|
void *__seq_open_private(struct file *f, const struct seq_operations *ops, |
|
int psize) |
|
{ |
|
int rc; |
|
void *private; |
|
struct seq_file *seq; |
|
|
|
private = kzalloc(psize, GFP_KERNEL_ACCOUNT); |
|
if (private == NULL) |
|
goto out; |
|
|
|
rc = seq_open(f, ops); |
|
if (rc < 0) |
|
goto out_free; |
|
|
|
seq = f->private_data; |
|
seq->private = private; |
|
return private; |
|
|
|
out_free: |
|
kfree(private); |
|
out: |
|
return NULL; |
|
} |
|
EXPORT_SYMBOL(__seq_open_private); |
|
|
|
int seq_open_private(struct file *filp, const struct seq_operations *ops, |
|
int psize) |
|
{ |
|
return __seq_open_private(filp, ops, psize) ? 0 : -ENOMEM; |
|
} |
|
EXPORT_SYMBOL(seq_open_private); |
|
|
|
void seq_putc(struct seq_file *m, char c) |
|
{ |
|
if (m->count >= m->size) |
|
return; |
|
|
|
m->buf[m->count++] = c; |
|
} |
|
EXPORT_SYMBOL(seq_putc); |
|
|
|
void seq_puts(struct seq_file *m, const char *s) |
|
{ |
|
int len = strlen(s); |
|
|
|
if (m->count + len >= m->size) { |
|
seq_set_overflow(m); |
|
return; |
|
} |
|
memcpy(m->buf + m->count, s, len); |
|
m->count += len; |
|
} |
|
EXPORT_SYMBOL(seq_puts); |
|
|
|
/** |
|
* seq_put_decimal_ull_width - A helper routine for putting decimal numbers |
|
* without rich format of printf(). |
|
* only 'unsigned long long' is supported. |
|
* @m: seq_file identifying the buffer to which data should be written |
|
* @delimiter: a string which is printed before the number |
|
* @num: the number |
|
* @width: a minimum field width |
|
* |
|
* This routine will put strlen(delimiter) + number into seq_filed. |
|
* This routine is very quick when you show lots of numbers. |
|
* In usual cases, it will be better to use seq_printf(). It's easier to read. |
|
*/ |
|
void seq_put_decimal_ull_width(struct seq_file *m, const char *delimiter, |
|
unsigned long long num, unsigned int width) |
|
{ |
|
int len; |
|
|
|
if (m->count + 2 >= m->size) /* we'll write 2 bytes at least */ |
|
goto overflow; |
|
|
|
if (delimiter && delimiter[0]) { |
|
if (delimiter[1] == 0) |
|
seq_putc(m, delimiter[0]); |
|
else |
|
seq_puts(m, delimiter); |
|
} |
|
|
|
if (!width) |
|
width = 1; |
|
|
|
if (m->count + width >= m->size) |
|
goto overflow; |
|
|
|
len = num_to_str(m->buf + m->count, m->size - m->count, num, width); |
|
if (!len) |
|
goto overflow; |
|
|
|
m->count += len; |
|
return; |
|
|
|
overflow: |
|
seq_set_overflow(m); |
|
} |
|
|
|
void seq_put_decimal_ull(struct seq_file *m, const char *delimiter, |
|
unsigned long long num) |
|
{ |
|
return seq_put_decimal_ull_width(m, delimiter, num, 0); |
|
} |
|
EXPORT_SYMBOL(seq_put_decimal_ull); |
|
|
|
/** |
|
* seq_put_hex_ll - put a number in hexadecimal notation |
|
* @m: seq_file identifying the buffer to which data should be written |
|
* @delimiter: a string which is printed before the number |
|
* @v: the number |
|
* @width: a minimum field width |
|
* |
|
* seq_put_hex_ll(m, "", v, 8) is equal to seq_printf(m, "%08llx", v) |
|
* |
|
* This routine is very quick when you show lots of numbers. |
|
* In usual cases, it will be better to use seq_printf(). It's easier to read. |
|
*/ |
|
void seq_put_hex_ll(struct seq_file *m, const char *delimiter, |
|
unsigned long long v, unsigned int width) |
|
{ |
|
unsigned int len; |
|
int i; |
|
|
|
if (delimiter && delimiter[0]) { |
|
if (delimiter[1] == 0) |
|
seq_putc(m, delimiter[0]); |
|
else |
|
seq_puts(m, delimiter); |
|
} |
|
|
|
/* If x is 0, the result of __builtin_clzll is undefined */ |
|
if (v == 0) |
|
len = 1; |
|
else |
|
len = (sizeof(v) * 8 - __builtin_clzll(v) + 3) / 4; |
|
|
|
if (len < width) |
|
len = width; |
|
|
|
if (m->count + len > m->size) { |
|
seq_set_overflow(m); |
|
return; |
|
} |
|
|
|
for (i = len - 1; i >= 0; i--) { |
|
m->buf[m->count + i] = hex_asc[0xf & v]; |
|
v = v >> 4; |
|
} |
|
m->count += len; |
|
} |
|
|
|
void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num) |
|
{ |
|
int len; |
|
|
|
if (m->count + 3 >= m->size) /* we'll write 2 bytes at least */ |
|
goto overflow; |
|
|
|
if (delimiter && delimiter[0]) { |
|
if (delimiter[1] == 0) |
|
seq_putc(m, delimiter[0]); |
|
else |
|
seq_puts(m, delimiter); |
|
} |
|
|
|
if (m->count + 2 >= m->size) |
|
goto overflow; |
|
|
|
if (num < 0) { |
|
m->buf[m->count++] = '-'; |
|
num = -num; |
|
} |
|
|
|
if (num < 10) { |
|
m->buf[m->count++] = num + '0'; |
|
return; |
|
} |
|
|
|
len = num_to_str(m->buf + m->count, m->size - m->count, num, 0); |
|
if (!len) |
|
goto overflow; |
|
|
|
m->count += len; |
|
return; |
|
|
|
overflow: |
|
seq_set_overflow(m); |
|
} |
|
EXPORT_SYMBOL(seq_put_decimal_ll); |
|
|
|
/** |
|
* seq_write - write arbitrary data to buffer |
|
* @seq: seq_file identifying the buffer to which data should be written |
|
* @data: data address |
|
* @len: number of bytes |
|
* |
|
* Return 0 on success, non-zero otherwise. |
|
*/ |
|
int seq_write(struct seq_file *seq, const void *data, size_t len) |
|
{ |
|
if (seq->count + len < seq->size) { |
|
memcpy(seq->buf + seq->count, data, len); |
|
seq->count += len; |
|
return 0; |
|
} |
|
seq_set_overflow(seq); |
|
return -1; |
|
} |
|
EXPORT_SYMBOL(seq_write); |
|
|
|
/** |
|
* seq_pad - write padding spaces to buffer |
|
* @m: seq_file identifying the buffer to which data should be written |
|
* @c: the byte to append after padding if non-zero |
|
*/ |
|
void seq_pad(struct seq_file *m, char c) |
|
{ |
|
int size = m->pad_until - m->count; |
|
if (size > 0) { |
|
if (size + m->count > m->size) { |
|
seq_set_overflow(m); |
|
return; |
|
} |
|
memset(m->buf + m->count, ' ', size); |
|
m->count += size; |
|
} |
|
if (c) |
|
seq_putc(m, c); |
|
} |
|
EXPORT_SYMBOL(seq_pad); |
|
|
|
/* A complete analogue of print_hex_dump() */ |
|
void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type, |
|
int rowsize, int groupsize, const void *buf, size_t len, |
|
bool ascii) |
|
{ |
|
const u8 *ptr = buf; |
|
int i, linelen, remaining = len; |
|
char *buffer; |
|
size_t size; |
|
int ret; |
|
|
|
if (rowsize != 16 && rowsize != 32) |
|
rowsize = 16; |
|
|
|
for (i = 0; i < len && !seq_has_overflowed(m); i += rowsize) { |
|
linelen = min(remaining, rowsize); |
|
remaining -= rowsize; |
|
|
|
switch (prefix_type) { |
|
case DUMP_PREFIX_ADDRESS: |
|
seq_printf(m, "%s%p: ", prefix_str, ptr + i); |
|
break; |
|
case DUMP_PREFIX_OFFSET: |
|
seq_printf(m, "%s%.8x: ", prefix_str, i); |
|
break; |
|
default: |
|
seq_printf(m, "%s", prefix_str); |
|
break; |
|
} |
|
|
|
size = seq_get_buf(m, &buffer); |
|
ret = hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize, |
|
buffer, size, ascii); |
|
seq_commit(m, ret < size ? ret : -1); |
|
|
|
seq_putc(m, '\n'); |
|
} |
|
} |
|
EXPORT_SYMBOL(seq_hex_dump); |
|
|
|
struct list_head *seq_list_start(struct list_head *head, loff_t pos) |
|
{ |
|
struct list_head *lh; |
|
|
|
list_for_each(lh, head) |
|
if (pos-- == 0) |
|
return lh; |
|
|
|
return NULL; |
|
} |
|
EXPORT_SYMBOL(seq_list_start); |
|
|
|
struct list_head *seq_list_start_head(struct list_head *head, loff_t pos) |
|
{ |
|
if (!pos) |
|
return head; |
|
|
|
return seq_list_start(head, pos - 1); |
|
} |
|
EXPORT_SYMBOL(seq_list_start_head); |
|
|
|
struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos) |
|
{ |
|
struct list_head *lh; |
|
|
|
lh = ((struct list_head *)v)->next; |
|
++*ppos; |
|
return lh == head ? NULL : lh; |
|
} |
|
EXPORT_SYMBOL(seq_list_next); |
|
|
|
struct list_head *seq_list_start_rcu(struct list_head *head, loff_t pos) |
|
{ |
|
struct list_head *lh; |
|
|
|
list_for_each_rcu(lh, head) |
|
if (pos-- == 0) |
|
return lh; |
|
|
|
return NULL; |
|
} |
|
EXPORT_SYMBOL(seq_list_start_rcu); |
|
|
|
struct list_head *seq_list_start_head_rcu(struct list_head *head, loff_t pos) |
|
{ |
|
if (!pos) |
|
return head; |
|
|
|
return seq_list_start_rcu(head, pos - 1); |
|
} |
|
EXPORT_SYMBOL(seq_list_start_head_rcu); |
|
|
|
struct list_head *seq_list_next_rcu(void *v, struct list_head *head, |
|
loff_t *ppos) |
|
{ |
|
struct list_head *lh; |
|
|
|
lh = list_next_rcu((struct list_head *)v); |
|
++*ppos; |
|
return lh == head ? NULL : lh; |
|
} |
|
EXPORT_SYMBOL(seq_list_next_rcu); |
|
|
|
/** |
|
* seq_hlist_start - start an iteration of a hlist |
|
* @head: the head of the hlist |
|
* @pos: the start position of the sequence |
|
* |
|
* Called at seq_file->op->start(). |
|
*/ |
|
struct hlist_node *seq_hlist_start(struct hlist_head *head, loff_t pos) |
|
{ |
|
struct hlist_node *node; |
|
|
|
hlist_for_each(node, head) |
|
if (pos-- == 0) |
|
return node; |
|
return NULL; |
|
} |
|
EXPORT_SYMBOL(seq_hlist_start); |
|
|
|
/** |
|
* seq_hlist_start_head - start an iteration of a hlist |
|
* @head: the head of the hlist |
|
* @pos: the start position of the sequence |
|
* |
|
* Called at seq_file->op->start(). Call this function if you want to |
|
* print a header at the top of the output. |
|
*/ |
|
struct hlist_node *seq_hlist_start_head(struct hlist_head *head, loff_t pos) |
|
{ |
|
if (!pos) |
|
return SEQ_START_TOKEN; |
|
|
|
return seq_hlist_start(head, pos - 1); |
|
} |
|
EXPORT_SYMBOL(seq_hlist_start_head); |
|
|
|
/** |
|
* seq_hlist_next - move to the next position of the hlist |
|
* @v: the current iterator |
|
* @head: the head of the hlist |
|
* @ppos: the current position |
|
* |
|
* Called at seq_file->op->next(). |
|
*/ |
|
struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head, |
|
loff_t *ppos) |
|
{ |
|
struct hlist_node *node = v; |
|
|
|
++*ppos; |
|
if (v == SEQ_START_TOKEN) |
|
return head->first; |
|
else |
|
return node->next; |
|
} |
|
EXPORT_SYMBOL(seq_hlist_next); |
|
|
|
/** |
|
* seq_hlist_start_rcu - start an iteration of a hlist protected by RCU |
|
* @head: the head of the hlist |
|
* @pos: the start position of the sequence |
|
* |
|
* Called at seq_file->op->start(). |
|
* |
|
* This list-traversal primitive may safely run concurrently with |
|
* the _rcu list-mutation primitives such as hlist_add_head_rcu() |
|
* as long as the traversal is guarded by rcu_read_lock(). |
|
*/ |
|
struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head, |
|
loff_t pos) |
|
{ |
|
struct hlist_node *node; |
|
|
|
__hlist_for_each_rcu(node, head) |
|
if (pos-- == 0) |
|
return node; |
|
return NULL; |
|
} |
|
EXPORT_SYMBOL(seq_hlist_start_rcu); |
|
|
|
/** |
|
* seq_hlist_start_head_rcu - start an iteration of a hlist protected by RCU |
|
* @head: the head of the hlist |
|
* @pos: the start position of the sequence |
|
* |
|
* Called at seq_file->op->start(). Call this function if you want to |
|
* print a header at the top of the output. |
|
* |
|
* This list-traversal primitive may safely run concurrently with |
|
* the _rcu list-mutation primitives such as hlist_add_head_rcu() |
|
* as long as the traversal is guarded by rcu_read_lock(). |
|
*/ |
|
struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head, |
|
loff_t pos) |
|
{ |
|
if (!pos) |
|
return SEQ_START_TOKEN; |
|
|
|
return seq_hlist_start_rcu(head, pos - 1); |
|
} |
|
EXPORT_SYMBOL(seq_hlist_start_head_rcu); |
|
|
|
/** |
|
* seq_hlist_next_rcu - move to the next position of the hlist protected by RCU |
|
* @v: the current iterator |
|
* @head: the head of the hlist |
|
* @ppos: the current position |
|
* |
|
* Called at seq_file->op->next(). |
|
* |
|
* This list-traversal primitive may safely run concurrently with |
|
* the _rcu list-mutation primitives such as hlist_add_head_rcu() |
|
* as long as the traversal is guarded by rcu_read_lock(). |
|
*/ |
|
struct hlist_node *seq_hlist_next_rcu(void *v, |
|
struct hlist_head *head, |
|
loff_t *ppos) |
|
{ |
|
struct hlist_node *node = v; |
|
|
|
++*ppos; |
|
if (v == SEQ_START_TOKEN) |
|
return rcu_dereference(head->first); |
|
else |
|
return rcu_dereference(node->next); |
|
} |
|
EXPORT_SYMBOL(seq_hlist_next_rcu); |
|
|
|
/** |
|
* seq_hlist_start_percpu - start an iteration of a percpu hlist array |
|
* @head: pointer to percpu array of struct hlist_heads |
|
* @cpu: pointer to cpu "cursor" |
|
* @pos: start position of sequence |
|
* |
|
* Called at seq_file->op->start(). |
|
*/ |
|
struct hlist_node * |
|
seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos) |
|
{ |
|
struct hlist_node *node; |
|
|
|
for_each_possible_cpu(*cpu) { |
|
hlist_for_each(node, per_cpu_ptr(head, *cpu)) { |
|
if (pos-- == 0) |
|
return node; |
|
} |
|
} |
|
return NULL; |
|
} |
|
EXPORT_SYMBOL(seq_hlist_start_percpu); |
|
|
|
/** |
|
* seq_hlist_next_percpu - move to the next position of the percpu hlist array |
|
* @v: pointer to current hlist_node |
|
* @head: pointer to percpu array of struct hlist_heads |
|
* @cpu: pointer to cpu "cursor" |
|
* @pos: start position of sequence |
|
* |
|
* Called at seq_file->op->next(). |
|
*/ |
|
struct hlist_node * |
|
seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, |
|
int *cpu, loff_t *pos) |
|
{ |
|
struct hlist_node *node = v; |
|
|
|
++*pos; |
|
|
|
if (node->next) |
|
return node->next; |
|
|
|
for (*cpu = cpumask_next(*cpu, cpu_possible_mask); *cpu < nr_cpu_ids; |
|
*cpu = cpumask_next(*cpu, cpu_possible_mask)) { |
|
struct hlist_head *bucket = per_cpu_ptr(head, *cpu); |
|
|
|
if (!hlist_empty(bucket)) |
|
return bucket->first; |
|
} |
|
return NULL; |
|
} |
|
EXPORT_SYMBOL(seq_hlist_next_percpu); |
|
|
|
void __init seq_file_init(void) |
|
{ |
|
seq_file_cache = KMEM_CACHE(seq_file, SLAB_ACCOUNT|SLAB_PANIC); |
|
}
|
|
|