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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /fs/seq_file.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/seq_file.c')
-rw-r--r--fs/seq_file.c1150
1 files changed, 1150 insertions, 0 deletions
diff --git a/fs/seq_file.c b/fs/seq_file.c
new file mode 100644
index 000000000..f5fdaf3b1
--- /dev/null
+++ b/fs/seq_file.c
@@ -0,0 +1,1150 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/seq_file.c
+ *
+ * helper functions for making synthetic files from sequences of records.
+ * initial implementation -- AV, Oct 2001.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/cache.h>
+#include <linux/fs.h>
+#include <linux/export.h>
+#include <linux/seq_file.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include <linux/cred.h>
+#include <linux/mm.h>
+#include <linux/printk.h>
+#include <linux/string_helpers.h>
+#include <linux/uio.h>
+
+#include <linux/uaccess.h>
+#include <asm/page.h>
+
+static struct kmem_cache *seq_file_cache __ro_after_init;
+
+static void seq_set_overflow(struct seq_file *m)
+{
+ m->count = m->size;
+}
+
+static void *seq_buf_alloc(unsigned long size)
+{
+ if (unlikely(size > MAX_RW_COUNT))
+ return NULL;
+
+ return kvmalloc(size, GFP_KERNEL_ACCOUNT);
+}
+
+/**
+ * seq_open - initialize sequential file
+ * @file: file we initialize
+ * @op: method table describing the sequence
+ *
+ * seq_open() sets @file, associating it with a sequence described
+ * by @op. @op->start() sets the iterator up and returns the first
+ * element of sequence. @op->stop() shuts it down. @op->next()
+ * returns the next element of sequence. @op->show() prints element
+ * into the buffer. In case of error ->start() and ->next() return
+ * ERR_PTR(error). In the end of sequence they return %NULL. ->show()
+ * returns 0 in case of success and negative number in case of error.
+ * Returning SEQ_SKIP means "discard this element and move on".
+ * Note: seq_open() will allocate a struct seq_file and store its
+ * pointer in @file->private_data. This pointer should not be modified.
+ */
+int seq_open(struct file *file, const struct seq_operations *op)
+{
+ struct seq_file *p;
+
+ WARN_ON(file->private_data);
+
+ p = kmem_cache_zalloc(seq_file_cache, GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+
+ file->private_data = p;
+
+ mutex_init(&p->lock);
+ p->op = op;
+
+ // No refcounting: the lifetime of 'p' is constrained
+ // to the lifetime of the file.
+ p->file = file;
+
+ /*
+ * seq_files support lseek() and pread(). They do not implement
+ * write() at all, but we clear FMODE_PWRITE here for historical
+ * reasons.
+ *
+ * If a client of seq_files a) implements file.write() and b) wishes to
+ * support pwrite() then that client will need to implement its own
+ * file.open() which calls seq_open() and then sets FMODE_PWRITE.
+ */
+ file->f_mode &= ~FMODE_PWRITE;
+ return 0;
+}
+EXPORT_SYMBOL(seq_open);
+
+static int traverse(struct seq_file *m, loff_t offset)
+{
+ loff_t pos = 0;
+ int error = 0;
+ void *p;
+
+ m->index = 0;
+ m->count = m->from = 0;
+ if (!offset)
+ return 0;
+
+ if (!m->buf) {
+ m->buf = seq_buf_alloc(m->size = PAGE_SIZE);
+ if (!m->buf)
+ return -ENOMEM;
+ }
+ p = m->op->start(m, &m->index);
+ while (p) {
+ error = PTR_ERR(p);
+ if (IS_ERR(p))
+ break;
+ error = m->op->show(m, p);
+ if (error < 0)
+ break;
+ if (unlikely(error)) {
+ error = 0;
+ m->count = 0;
+ }
+ if (seq_has_overflowed(m))
+ goto Eoverflow;
+ p = m->op->next(m, p, &m->index);
+ if (pos + m->count > offset) {
+ m->from = offset - pos;
+ m->count -= m->from;
+ break;
+ }
+ pos += m->count;
+ m->count = 0;
+ if (pos == offset)
+ break;
+ }
+ m->op->stop(m, p);
+ return error;
+
+Eoverflow:
+ m->op->stop(m, p);
+ kvfree(m->buf);
+ m->count = 0;
+ m->buf = seq_buf_alloc(m->size <<= 1);
+ return !m->buf ? -ENOMEM : -EAGAIN;
+}
+
+/**
+ * seq_read - ->read() method for sequential files.
+ * @file: the file to read from
+ * @buf: the buffer to read to
+ * @size: the maximum number of bytes to read
+ * @ppos: the current position in the file
+ *
+ * Ready-made ->f_op->read()
+ */
+ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
+{
+ struct iovec iov = { .iov_base = buf, .iov_len = size};
+ struct kiocb kiocb;
+ struct iov_iter iter;
+ ssize_t ret;
+
+ init_sync_kiocb(&kiocb, file);
+ iov_iter_init(&iter, ITER_DEST, &iov, 1, size);
+
+ kiocb.ki_pos = *ppos;
+ ret = seq_read_iter(&kiocb, &iter);
+ *ppos = kiocb.ki_pos;
+ return ret;
+}
+EXPORT_SYMBOL(seq_read);
+
+/*
+ * Ready-made ->f_op->read_iter()
+ */
+ssize_t seq_read_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+ struct seq_file *m = iocb->ki_filp->private_data;
+ size_t copied = 0;
+ size_t n;
+ void *p;
+ int err = 0;
+
+ if (!iov_iter_count(iter))
+ return 0;
+
+ mutex_lock(&m->lock);
+
+ /*
+ * if request is to read from zero offset, reset iterator to first
+ * record as it might have been already advanced by previous requests
+ */
+ if (iocb->ki_pos == 0) {
+ m->index = 0;
+ m->count = 0;
+ }
+
+ /* Don't assume ki_pos is where we left it */
+ if (unlikely(iocb->ki_pos != m->read_pos)) {
+ while ((err = traverse(m, iocb->ki_pos)) == -EAGAIN)
+ ;
+ if (err) {
+ /* With prejudice... */
+ m->read_pos = 0;
+ m->index = 0;
+ m->count = 0;
+ goto Done;
+ } else {
+ m->read_pos = iocb->ki_pos;
+ }
+ }
+
+ /* grab buffer if we didn't have one */
+ if (!m->buf) {
+ m->buf = seq_buf_alloc(m->size = PAGE_SIZE);
+ if (!m->buf)
+ goto Enomem;
+ }
+ // something left in the buffer - copy it out first
+ if (m->count) {
+ n = copy_to_iter(m->buf + m->from, m->count, iter);
+ m->count -= n;
+ m->from += n;
+ copied += n;
+ if (m->count) // hadn't managed to copy everything
+ goto Done;
+ }
+ // get a non-empty record in the buffer
+ m->from = 0;
+ p = m->op->start(m, &m->index);
+ while (1) {
+ err = PTR_ERR(p);
+ if (!p || IS_ERR(p)) // EOF or an error
+ break;
+ err = m->op->show(m, p);
+ if (err < 0) // hard error
+ break;
+ if (unlikely(err)) // ->show() says "skip it"
+ m->count = 0;
+ if (unlikely(!m->count)) { // empty record
+ p = m->op->next(m, p, &m->index);
+ continue;
+ }
+ if (!seq_has_overflowed(m)) // got it
+ goto Fill;
+ // need a bigger buffer
+ m->op->stop(m, p);
+ kvfree(m->buf);
+ m->count = 0;
+ m->buf = seq_buf_alloc(m->size <<= 1);
+ if (!m->buf)
+ goto Enomem;
+ p = m->op->start(m, &m->index);
+ }
+ // EOF or an error
+ m->op->stop(m, p);
+ m->count = 0;
+ goto Done;
+Fill:
+ // one non-empty record is in the buffer; if they want more,
+ // try to fit more in, but in any case we need to advance
+ // the iterator once for every record shown.
+ while (1) {
+ size_t offs = m->count;
+ loff_t pos = m->index;
+
+ p = m->op->next(m, p, &m->index);
+ if (pos == m->index) {
+ pr_info_ratelimited("buggy .next function %ps did not update position index\n",
+ m->op->next);
+ m->index++;
+ }
+ if (!p || IS_ERR(p)) // no next record for us
+ break;
+ if (m->count >= iov_iter_count(iter))
+ break;
+ err = m->op->show(m, p);
+ if (err > 0) { // ->show() says "skip it"
+ m->count = offs;
+ } else if (err || seq_has_overflowed(m)) {
+ m->count = offs;
+ break;
+ }
+ }
+ m->op->stop(m, p);
+ n = copy_to_iter(m->buf, m->count, iter);
+ copied += n;
+ m->count -= n;
+ m->from = n;
+Done:
+ if (unlikely(!copied)) {
+ copied = m->count ? -EFAULT : err;
+ } else {
+ iocb->ki_pos += copied;
+ m->read_pos += copied;
+ }
+ mutex_unlock(&m->lock);
+ return copied;
+Enomem:
+ err = -ENOMEM;
+ goto Done;
+}
+EXPORT_SYMBOL(seq_read_iter);
+
+/**
+ * seq_lseek - ->llseek() method for sequential files.
+ * @file: the file in question
+ * @offset: new position
+ * @whence: 0 for absolute, 1 for relative position
+ *
+ * Ready-made ->f_op->llseek()
+ */
+loff_t seq_lseek(struct file *file, loff_t offset, int whence)
+{
+ struct seq_file *m = file->private_data;
+ loff_t retval = -EINVAL;
+
+ mutex_lock(&m->lock);
+ switch (whence) {
+ case SEEK_CUR:
+ offset += file->f_pos;
+ fallthrough;
+ case SEEK_SET:
+ if (offset < 0)
+ break;
+ retval = offset;
+ if (offset != m->read_pos) {
+ while ((retval = traverse(m, offset)) == -EAGAIN)
+ ;
+ if (retval) {
+ /* with extreme prejudice... */
+ file->f_pos = 0;
+ m->read_pos = 0;
+ m->index = 0;
+ m->count = 0;
+ } else {
+ m->read_pos = offset;
+ retval = file->f_pos = offset;
+ }
+ } else {
+ file->f_pos = offset;
+ }
+ }
+ mutex_unlock(&m->lock);
+ return retval;
+}
+EXPORT_SYMBOL(seq_lseek);
+
+/**
+ * seq_release - free the structures associated with sequential file.
+ * @file: file in question
+ * @inode: its inode
+ *
+ * Frees the structures associated with sequential file; can be used
+ * as ->f_op->release() if you don't have private data to destroy.
+ */
+int seq_release(struct inode *inode, struct file *file)
+{
+ struct seq_file *m = file->private_data;
+ kvfree(m->buf);
+ kmem_cache_free(seq_file_cache, m);
+ return 0;
+}
+EXPORT_SYMBOL(seq_release);
+
+/**
+ * seq_escape_mem - print data into buffer, escaping some characters
+ * @m: target buffer
+ * @src: source buffer
+ * @len: size of source buffer
+ * @flags: flags to pass to string_escape_mem()
+ * @esc: set of characters that need escaping
+ *
+ * Puts data into buffer, replacing each occurrence of character from
+ * given class (defined by @flags and @esc) with printable escaped sequence.
+ *
+ * Use seq_has_overflowed() to check for errors.
+ */
+void seq_escape_mem(struct seq_file *m, const char *src, size_t len,
+ unsigned int flags, const char *esc)
+{
+ char *buf;
+ size_t size = seq_get_buf(m, &buf);
+ int ret;
+
+ ret = string_escape_mem(src, len, buf, size, flags, esc);
+ seq_commit(m, ret < size ? ret : -1);
+}
+EXPORT_SYMBOL(seq_escape_mem);
+
+void seq_vprintf(struct seq_file *m, const char *f, va_list args)
+{
+ int len;
+
+ if (m->count < m->size) {
+ len = vsnprintf(m->buf + m->count, m->size - m->count, f, args);
+ if (m->count + len < m->size) {
+ m->count += len;
+ return;
+ }
+ }
+ seq_set_overflow(m);
+}
+EXPORT_SYMBOL(seq_vprintf);
+
+void seq_printf(struct seq_file *m, const char *f, ...)
+{
+ va_list args;
+
+ va_start(args, f);
+ seq_vprintf(m, f, args);
+ va_end(args);
+}
+EXPORT_SYMBOL(seq_printf);
+
+#ifdef CONFIG_BINARY_PRINTF
+void seq_bprintf(struct seq_file *m, const char *f, const u32 *binary)
+{
+ int len;
+
+ if (m->count < m->size) {
+ len = bstr_printf(m->buf + m->count, m->size - m->count, f,
+ binary);
+ if (m->count + len < m->size) {
+ m->count += len;
+ return;
+ }
+ }
+ seq_set_overflow(m);
+}
+EXPORT_SYMBOL(seq_bprintf);
+#endif /* CONFIG_BINARY_PRINTF */
+
+/**
+ * mangle_path - mangle and copy path to buffer beginning
+ * @s: buffer start
+ * @p: beginning of path in above buffer
+ * @esc: set of characters that need escaping
+ *
+ * Copy the path from @p to @s, replacing each occurrence of character from
+ * @esc with usual octal escape.
+ * Returns pointer past last written character in @s, or NULL in case of
+ * failure.
+ */
+char *mangle_path(char *s, const char *p, const char *esc)
+{
+ while (s <= p) {
+ char c = *p++;
+ if (!c) {
+ return s;
+ } else if (!strchr(esc, c)) {
+ *s++ = c;
+ } else if (s + 4 > p) {
+ break;
+ } else {
+ *s++ = '\\';
+ *s++ = '0' + ((c & 0300) >> 6);
+ *s++ = '0' + ((c & 070) >> 3);
+ *s++ = '0' + (c & 07);
+ }
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(mangle_path);
+
+/**
+ * seq_path - seq_file interface to print a pathname
+ * @m: the seq_file handle
+ * @path: the struct path to print
+ * @esc: set of characters to escape in the output
+ *
+ * return the absolute path of 'path', as represented by the
+ * dentry / mnt pair in the path parameter.
+ */
+int seq_path(struct seq_file *m, const struct path *path, const char *esc)
+{
+ 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)) {
+ 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);
+}