1 // SPDX-License-Identifier: GPL-2.0
5 * helper functions for making synthetic files from sequences of records.
6 * initial implementation -- AV, Oct 2001.
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11 #include <linux/cache.h>
13 #include <linux/export.h>
14 #include <linux/seq_file.h>
15 #include <linux/vmalloc.h>
16 #include <linux/slab.h>
17 #include <linux/cred.h>
19 #include <linux/printk.h>
20 #include <linux/string_helpers.h>
21 #include <linux/uio.h>
23 #include <linux/uaccess.h>
26 static struct kmem_cache
*seq_file_cache __ro_after_init
;
28 static void seq_set_overflow(struct seq_file
*m
)
33 static void *seq_buf_alloc(unsigned long size
)
35 return kvmalloc(size
, GFP_KERNEL_ACCOUNT
);
39 * seq_open - initialize sequential file
40 * @file: file we initialize
41 * @op: method table describing the sequence
43 * seq_open() sets @file, associating it with a sequence described
44 * by @op. @op->start() sets the iterator up and returns the first
45 * element of sequence. @op->stop() shuts it down. @op->next()
46 * returns the next element of sequence. @op->show() prints element
47 * into the buffer. In case of error ->start() and ->next() return
48 * ERR_PTR(error). In the end of sequence they return %NULL. ->show()
49 * returns 0 in case of success and negative number in case of error.
50 * Returning SEQ_SKIP means "discard this element and move on".
51 * Note: seq_open() will allocate a struct seq_file and store its
52 * pointer in @file->private_data. This pointer should not be modified.
54 int seq_open(struct file
*file
, const struct seq_operations
*op
)
58 WARN_ON(file
->private_data
);
60 p
= kmem_cache_zalloc(seq_file_cache
, GFP_KERNEL
);
64 file
->private_data
= p
;
69 // No refcounting: the lifetime of 'p' is constrained
70 // to the lifetime of the file.
74 * seq_files support lseek() and pread(). They do not implement
75 * write() at all, but we clear FMODE_PWRITE here for historical
78 * If a client of seq_files a) implements file.write() and b) wishes to
79 * support pwrite() then that client will need to implement its own
80 * file.open() which calls seq_open() and then sets FMODE_PWRITE.
82 file
->f_mode
&= ~FMODE_PWRITE
;
85 EXPORT_SYMBOL(seq_open
);
87 static int traverse(struct seq_file
*m
, loff_t offset
)
94 m
->count
= m
->from
= 0;
99 m
->buf
= seq_buf_alloc(m
->size
= PAGE_SIZE
);
103 p
= m
->op
->start(m
, &m
->index
);
108 error
= m
->op
->show(m
, p
);
111 if (unlikely(error
)) {
115 if (seq_has_overflowed(m
))
117 p
= m
->op
->next(m
, p
, &m
->index
);
118 if (pos
+ m
->count
> offset
) {
119 m
->from
= offset
- pos
;
135 m
->buf
= seq_buf_alloc(m
->size
<<= 1);
136 return !m
->buf
? -ENOMEM
: -EAGAIN
;
140 * seq_read - ->read() method for sequential files.
141 * @file: the file to read from
142 * @buf: the buffer to read to
143 * @size: the maximum number of bytes to read
144 * @ppos: the current position in the file
146 * Ready-made ->f_op->read()
148 ssize_t
seq_read(struct file
*file
, char __user
*buf
, size_t size
, loff_t
*ppos
)
150 struct iovec iov
= { .iov_base
= buf
, .iov_len
= size
};
152 struct iov_iter iter
;
155 init_sync_kiocb(&kiocb
, file
);
156 iov_iter_init(&iter
, READ
, &iov
, 1, size
);
158 kiocb
.ki_pos
= *ppos
;
159 ret
= seq_read_iter(&kiocb
, &iter
);
160 *ppos
= kiocb
.ki_pos
;
163 EXPORT_SYMBOL(seq_read
);
166 * Ready-made ->f_op->read_iter()
168 ssize_t
seq_read_iter(struct kiocb
*iocb
, struct iov_iter
*iter
)
170 struct seq_file
*m
= iocb
->ki_filp
->private_data
;
176 if (!iov_iter_count(iter
))
179 mutex_lock(&m
->lock
);
182 * if request is to read from zero offset, reset iterator to first
183 * record as it might have been already advanced by previous requests
185 if (iocb
->ki_pos
== 0) {
190 /* Don't assume ki_pos is where we left it */
191 if (unlikely(iocb
->ki_pos
!= m
->read_pos
)) {
192 while ((err
= traverse(m
, iocb
->ki_pos
)) == -EAGAIN
)
195 /* With prejudice... */
201 m
->read_pos
= iocb
->ki_pos
;
205 /* grab buffer if we didn't have one */
207 m
->buf
= seq_buf_alloc(m
->size
= PAGE_SIZE
);
211 // something left in the buffer - copy it out first
213 n
= copy_to_iter(m
->buf
+ m
->from
, m
->count
, iter
);
217 if (m
->count
) // hadn't managed to copy everything
220 // get a non-empty record in the buffer
222 p
= m
->op
->start(m
, &m
->index
);
225 if (!p
|| IS_ERR(p
)) // EOF or an error
227 err
= m
->op
->show(m
, p
);
228 if (err
< 0) // hard error
230 if (unlikely(err
)) // ->show() says "skip it"
232 if (unlikely(!m
->count
)) { // empty record
233 p
= m
->op
->next(m
, p
, &m
->index
);
236 if (!seq_has_overflowed(m
)) // got it
238 // need a bigger buffer
242 m
->buf
= seq_buf_alloc(m
->size
<<= 1);
245 p
= m
->op
->start(m
, &m
->index
);
252 // one non-empty record is in the buffer; if they want more,
253 // try to fit more in, but in any case we need to advance
254 // the iterator once for every record shown.
256 size_t offs
= m
->count
;
257 loff_t pos
= m
->index
;
259 p
= m
->op
->next(m
, p
, &m
->index
);
260 if (pos
== m
->index
) {
261 pr_info_ratelimited("buggy .next function %ps did not update position index\n",
265 if (!p
|| IS_ERR(p
)) // no next record for us
267 if (m
->count
>= iov_iter_count(iter
))
269 err
= m
->op
->show(m
, p
);
270 if (err
> 0) { // ->show() says "skip it"
272 } else if (err
|| seq_has_overflowed(m
)) {
278 n
= copy_to_iter(m
->buf
, m
->count
, iter
);
283 if (unlikely(!copied
)) {
284 copied
= m
->count
? -EFAULT
: err
;
286 iocb
->ki_pos
+= copied
;
287 m
->read_pos
+= copied
;
289 mutex_unlock(&m
->lock
);
295 EXPORT_SYMBOL(seq_read_iter
);
298 * seq_lseek - ->llseek() method for sequential files.
299 * @file: the file in question
300 * @offset: new position
301 * @whence: 0 for absolute, 1 for relative position
303 * Ready-made ->f_op->llseek()
305 loff_t
seq_lseek(struct file
*file
, loff_t offset
, int whence
)
307 struct seq_file
*m
= file
->private_data
;
308 loff_t retval
= -EINVAL
;
310 mutex_lock(&m
->lock
);
313 offset
+= file
->f_pos
;
319 if (offset
!= m
->read_pos
) {
320 while ((retval
= traverse(m
, offset
)) == -EAGAIN
)
323 /* with extreme prejudice... */
329 m
->read_pos
= offset
;
330 retval
= file
->f_pos
= offset
;
333 file
->f_pos
= offset
;
336 mutex_unlock(&m
->lock
);
339 EXPORT_SYMBOL(seq_lseek
);
342 * seq_release - free the structures associated with sequential file.
343 * @file: file in question
346 * Frees the structures associated with sequential file; can be used
347 * as ->f_op->release() if you don't have private data to destroy.
349 int seq_release(struct inode
*inode
, struct file
*file
)
351 struct seq_file
*m
= file
->private_data
;
353 kmem_cache_free(seq_file_cache
, m
);
356 EXPORT_SYMBOL(seq_release
);
359 * seq_escape - print string into buffer, escaping some characters
362 * @esc: set of characters that need escaping
364 * Puts string into buffer, replacing each occurrence of character from
365 * @esc with usual octal escape.
366 * Use seq_has_overflowed() to check for errors.
368 void seq_escape(struct seq_file
*m
, const char *s
, const char *esc
)
371 size_t size
= seq_get_buf(m
, &buf
);
374 ret
= string_escape_str(s
, buf
, size
, ESCAPE_OCTAL
, esc
);
375 seq_commit(m
, ret
< size
? ret
: -1);
377 EXPORT_SYMBOL(seq_escape
);
379 void seq_escape_mem_ascii(struct seq_file
*m
, const char *src
, size_t isz
)
382 size_t size
= seq_get_buf(m
, &buf
);
385 ret
= string_escape_mem_ascii(src
, isz
, buf
, size
);
386 seq_commit(m
, ret
< size
? ret
: -1);
388 EXPORT_SYMBOL(seq_escape_mem_ascii
);
390 void seq_vprintf(struct seq_file
*m
, const char *f
, va_list args
)
394 if (m
->count
< m
->size
) {
395 len
= vsnprintf(m
->buf
+ m
->count
, m
->size
- m
->count
, f
, args
);
396 if (m
->count
+ len
< m
->size
) {
403 EXPORT_SYMBOL(seq_vprintf
);
405 void seq_printf(struct seq_file
*m
, const char *f
, ...)
410 seq_vprintf(m
, f
, args
);
413 EXPORT_SYMBOL(seq_printf
);
416 * mangle_path - mangle and copy path to buffer beginning
418 * @p: beginning of path in above buffer
419 * @esc: set of characters that need escaping
421 * Copy the path from @p to @s, replacing each occurrence of character from
422 * @esc with usual octal escape.
423 * Returns pointer past last written character in @s, or NULL in case of
426 char *mangle_path(char *s
, const char *p
, const char *esc
)
432 } else if (!strchr(esc
, c
)) {
434 } else if (s
+ 4 > p
) {
438 *s
++ = '0' + ((c
& 0300) >> 6);
439 *s
++ = '0' + ((c
& 070) >> 3);
440 *s
++ = '0' + (c
& 07);
445 EXPORT_SYMBOL(mangle_path
);
448 * seq_path - seq_file interface to print a pathname
449 * @m: the seq_file handle
450 * @path: the struct path to print
451 * @esc: set of characters to escape in the output
453 * return the absolute path of 'path', as represented by the
454 * dentry / mnt pair in the path parameter.
456 int seq_path(struct seq_file
*m
, const struct path
*path
, const char *esc
)
459 size_t size
= seq_get_buf(m
, &buf
);
463 char *p
= d_path(path
, buf
, size
);
465 char *end
= mangle_path(buf
, p
, esc
);
474 EXPORT_SYMBOL(seq_path
);
477 * seq_file_path - seq_file interface to print a pathname of a file
478 * @m: the seq_file handle
479 * @file: the struct file to print
480 * @esc: set of characters to escape in the output
482 * return the absolute path to the file.
484 int seq_file_path(struct seq_file
*m
, struct file
*file
, const char *esc
)
486 return seq_path(m
, &file
->f_path
, esc
);
488 EXPORT_SYMBOL(seq_file_path
);
491 * Same as seq_path, but relative to supplied root.
493 int seq_path_root(struct seq_file
*m
, const struct path
*path
,
494 const struct path
*root
, const char *esc
)
497 size_t size
= seq_get_buf(m
, &buf
);
498 int res
= -ENAMETOOLONG
;
503 p
= __d_path(path
, root
, buf
, size
);
508 char *end
= mangle_path(buf
, p
, esc
);
517 return res
< 0 && res
!= -ENAMETOOLONG
? res
: 0;
521 * returns the path of the 'dentry' from the root of its filesystem.
523 int seq_dentry(struct seq_file
*m
, struct dentry
*dentry
, const char *esc
)
526 size_t size
= seq_get_buf(m
, &buf
);
530 char *p
= dentry_path(dentry
, buf
, size
);
532 char *end
= mangle_path(buf
, p
, esc
);
541 EXPORT_SYMBOL(seq_dentry
);
543 static void *single_start(struct seq_file
*p
, loff_t
*pos
)
545 return NULL
+ (*pos
== 0);
548 static void *single_next(struct seq_file
*p
, void *v
, loff_t
*pos
)
554 static void single_stop(struct seq_file
*p
, void *v
)
558 int single_open(struct file
*file
, int (*show
)(struct seq_file
*, void *),
561 struct seq_operations
*op
= kmalloc(sizeof(*op
), GFP_KERNEL_ACCOUNT
);
565 op
->start
= single_start
;
566 op
->next
= single_next
;
567 op
->stop
= single_stop
;
569 res
= seq_open(file
, op
);
571 ((struct seq_file
*)file
->private_data
)->private = data
;
577 EXPORT_SYMBOL(single_open
);
579 int single_open_size(struct file
*file
, int (*show
)(struct seq_file
*, void *),
580 void *data
, size_t size
)
582 char *buf
= seq_buf_alloc(size
);
586 ret
= single_open(file
, show
, data
);
591 ((struct seq_file
*)file
->private_data
)->buf
= buf
;
592 ((struct seq_file
*)file
->private_data
)->size
= size
;
595 EXPORT_SYMBOL(single_open_size
);
597 int single_release(struct inode
*inode
, struct file
*file
)
599 const struct seq_operations
*op
= ((struct seq_file
*)file
->private_data
)->op
;
600 int res
= seq_release(inode
, file
);
604 EXPORT_SYMBOL(single_release
);
606 int seq_release_private(struct inode
*inode
, struct file
*file
)
608 struct seq_file
*seq
= file
->private_data
;
612 return seq_release(inode
, file
);
614 EXPORT_SYMBOL(seq_release_private
);
616 void *__seq_open_private(struct file
*f
, const struct seq_operations
*ops
,
621 struct seq_file
*seq
;
623 private = kzalloc(psize
, GFP_KERNEL_ACCOUNT
);
627 rc
= seq_open(f
, ops
);
631 seq
= f
->private_data
;
632 seq
->private = private;
640 EXPORT_SYMBOL(__seq_open_private
);
642 int seq_open_private(struct file
*filp
, const struct seq_operations
*ops
,
645 return __seq_open_private(filp
, ops
, psize
) ? 0 : -ENOMEM
;
647 EXPORT_SYMBOL(seq_open_private
);
649 void seq_putc(struct seq_file
*m
, char c
)
651 if (m
->count
>= m
->size
)
654 m
->buf
[m
->count
++] = c
;
656 EXPORT_SYMBOL(seq_putc
);
658 void seq_puts(struct seq_file
*m
, const char *s
)
662 if (m
->count
+ len
>= m
->size
) {
666 memcpy(m
->buf
+ m
->count
, s
, len
);
669 EXPORT_SYMBOL(seq_puts
);
672 * seq_put_decimal_ull_width - A helper routine for putting decimal numbers
673 * without rich format of printf().
674 * only 'unsigned long long' is supported.
675 * @m: seq_file identifying the buffer to which data should be written
676 * @delimiter: a string which is printed before the number
678 * @width: a minimum field width
680 * This routine will put strlen(delimiter) + number into seq_filed.
681 * This routine is very quick when you show lots of numbers.
682 * In usual cases, it will be better to use seq_printf(). It's easier to read.
684 void seq_put_decimal_ull_width(struct seq_file
*m
, const char *delimiter
,
685 unsigned long long num
, unsigned int width
)
689 if (m
->count
+ 2 >= m
->size
) /* we'll write 2 bytes at least */
692 if (delimiter
&& delimiter
[0]) {
693 if (delimiter
[1] == 0)
694 seq_putc(m
, delimiter
[0]);
696 seq_puts(m
, delimiter
);
702 if (m
->count
+ width
>= m
->size
)
705 len
= num_to_str(m
->buf
+ m
->count
, m
->size
- m
->count
, num
, width
);
716 void seq_put_decimal_ull(struct seq_file
*m
, const char *delimiter
,
717 unsigned long long num
)
719 return seq_put_decimal_ull_width(m
, delimiter
, num
, 0);
721 EXPORT_SYMBOL(seq_put_decimal_ull
);
724 * seq_put_hex_ll - put a number in hexadecimal notation
725 * @m: seq_file identifying the buffer to which data should be written
726 * @delimiter: a string which is printed before the number
728 * @width: a minimum field width
730 * seq_put_hex_ll(m, "", v, 8) is equal to seq_printf(m, "%08llx", v)
732 * This routine is very quick when you show lots of numbers.
733 * In usual cases, it will be better to use seq_printf(). It's easier to read.
735 void seq_put_hex_ll(struct seq_file
*m
, const char *delimiter
,
736 unsigned long long v
, unsigned int width
)
741 if (delimiter
&& delimiter
[0]) {
742 if (delimiter
[1] == 0)
743 seq_putc(m
, delimiter
[0]);
745 seq_puts(m
, delimiter
);
748 /* If x is 0, the result of __builtin_clzll is undefined */
752 len
= (sizeof(v
) * 8 - __builtin_clzll(v
) + 3) / 4;
757 if (m
->count
+ len
> m
->size
) {
762 for (i
= len
- 1; i
>= 0; i
--) {
763 m
->buf
[m
->count
+ i
] = hex_asc
[0xf & v
];
769 void seq_put_decimal_ll(struct seq_file
*m
, const char *delimiter
, long long num
)
773 if (m
->count
+ 3 >= m
->size
) /* we'll write 2 bytes at least */
776 if (delimiter
&& delimiter
[0]) {
777 if (delimiter
[1] == 0)
778 seq_putc(m
, delimiter
[0]);
780 seq_puts(m
, delimiter
);
783 if (m
->count
+ 2 >= m
->size
)
787 m
->buf
[m
->count
++] = '-';
792 m
->buf
[m
->count
++] = num
+ '0';
796 len
= num_to_str(m
->buf
+ m
->count
, m
->size
- m
->count
, num
, 0);
806 EXPORT_SYMBOL(seq_put_decimal_ll
);
809 * seq_write - write arbitrary data to buffer
810 * @seq: seq_file identifying the buffer to which data should be written
811 * @data: data address
812 * @len: number of bytes
814 * Return 0 on success, non-zero otherwise.
816 int seq_write(struct seq_file
*seq
, const void *data
, size_t len
)
818 if (seq
->count
+ len
< seq
->size
) {
819 memcpy(seq
->buf
+ seq
->count
, data
, len
);
823 seq_set_overflow(seq
);
826 EXPORT_SYMBOL(seq_write
);
829 * seq_pad - write padding spaces to buffer
830 * @m: seq_file identifying the buffer to which data should be written
831 * @c: the byte to append after padding if non-zero
833 void seq_pad(struct seq_file
*m
, char c
)
835 int size
= m
->pad_until
- m
->count
;
837 if (size
+ m
->count
> m
->size
) {
841 memset(m
->buf
+ m
->count
, ' ', size
);
847 EXPORT_SYMBOL(seq_pad
);
849 /* A complete analogue of print_hex_dump() */
850 void seq_hex_dump(struct seq_file
*m
, const char *prefix_str
, int prefix_type
,
851 int rowsize
, int groupsize
, const void *buf
, size_t len
,
855 int i
, linelen
, remaining
= len
;
860 if (rowsize
!= 16 && rowsize
!= 32)
863 for (i
= 0; i
< len
&& !seq_has_overflowed(m
); i
+= rowsize
) {
864 linelen
= min(remaining
, rowsize
);
865 remaining
-= rowsize
;
867 switch (prefix_type
) {
868 case DUMP_PREFIX_ADDRESS
:
869 seq_printf(m
, "%s%p: ", prefix_str
, ptr
+ i
);
871 case DUMP_PREFIX_OFFSET
:
872 seq_printf(m
, "%s%.8x: ", prefix_str
, i
);
875 seq_printf(m
, "%s", prefix_str
);
879 size
= seq_get_buf(m
, &buffer
);
880 ret
= hex_dump_to_buffer(ptr
+ i
, linelen
, rowsize
, groupsize
,
881 buffer
, size
, ascii
);
882 seq_commit(m
, ret
< size
? ret
: -1);
887 EXPORT_SYMBOL(seq_hex_dump
);
889 struct list_head
*seq_list_start(struct list_head
*head
, loff_t pos
)
891 struct list_head
*lh
;
893 list_for_each(lh
, head
)
899 EXPORT_SYMBOL(seq_list_start
);
901 struct list_head
*seq_list_start_head(struct list_head
*head
, loff_t pos
)
906 return seq_list_start(head
, pos
- 1);
908 EXPORT_SYMBOL(seq_list_start_head
);
910 struct list_head
*seq_list_next(void *v
, struct list_head
*head
, loff_t
*ppos
)
912 struct list_head
*lh
;
914 lh
= ((struct list_head
*)v
)->next
;
916 return lh
== head
? NULL
: lh
;
918 EXPORT_SYMBOL(seq_list_next
);
921 * seq_hlist_start - start an iteration of a hlist
922 * @head: the head of the hlist
923 * @pos: the start position of the sequence
925 * Called at seq_file->op->start().
927 struct hlist_node
*seq_hlist_start(struct hlist_head
*head
, loff_t pos
)
929 struct hlist_node
*node
;
931 hlist_for_each(node
, head
)
936 EXPORT_SYMBOL(seq_hlist_start
);
939 * seq_hlist_start_head - start an iteration of a hlist
940 * @head: the head of the hlist
941 * @pos: the start position of the sequence
943 * Called at seq_file->op->start(). Call this function if you want to
944 * print a header at the top of the output.
946 struct hlist_node
*seq_hlist_start_head(struct hlist_head
*head
, loff_t pos
)
949 return SEQ_START_TOKEN
;
951 return seq_hlist_start(head
, pos
- 1);
953 EXPORT_SYMBOL(seq_hlist_start_head
);
956 * seq_hlist_next - move to the next position of the hlist
957 * @v: the current iterator
958 * @head: the head of the hlist
959 * @ppos: the current position
961 * Called at seq_file->op->next().
963 struct hlist_node
*seq_hlist_next(void *v
, struct hlist_head
*head
,
966 struct hlist_node
*node
= v
;
969 if (v
== SEQ_START_TOKEN
)
974 EXPORT_SYMBOL(seq_hlist_next
);
977 * seq_hlist_start_rcu - start an iteration of a hlist protected by RCU
978 * @head: the head of the hlist
979 * @pos: the start position of the sequence
981 * Called at seq_file->op->start().
983 * This list-traversal primitive may safely run concurrently with
984 * the _rcu list-mutation primitives such as hlist_add_head_rcu()
985 * as long as the traversal is guarded by rcu_read_lock().
987 struct hlist_node
*seq_hlist_start_rcu(struct hlist_head
*head
,
990 struct hlist_node
*node
;
992 __hlist_for_each_rcu(node
, head
)
997 EXPORT_SYMBOL(seq_hlist_start_rcu
);
1000 * seq_hlist_start_head_rcu - start an iteration of a hlist protected by RCU
1001 * @head: the head of the hlist
1002 * @pos: the start position of the sequence
1004 * Called at seq_file->op->start(). Call this function if you want to
1005 * print a header at the top of the output.
1007 * This list-traversal primitive may safely run concurrently with
1008 * the _rcu list-mutation primitives such as hlist_add_head_rcu()
1009 * as long as the traversal is guarded by rcu_read_lock().
1011 struct hlist_node
*seq_hlist_start_head_rcu(struct hlist_head
*head
,
1015 return SEQ_START_TOKEN
;
1017 return seq_hlist_start_rcu(head
, pos
- 1);
1019 EXPORT_SYMBOL(seq_hlist_start_head_rcu
);
1022 * seq_hlist_next_rcu - move to the next position of the hlist protected by RCU
1023 * @v: the current iterator
1024 * @head: the head of the hlist
1025 * @ppos: the current position
1027 * Called at seq_file->op->next().
1029 * This list-traversal primitive may safely run concurrently with
1030 * the _rcu list-mutation primitives such as hlist_add_head_rcu()
1031 * as long as the traversal is guarded by rcu_read_lock().
1033 struct hlist_node
*seq_hlist_next_rcu(void *v
,
1034 struct hlist_head
*head
,
1037 struct hlist_node
*node
= v
;
1040 if (v
== SEQ_START_TOKEN
)
1041 return rcu_dereference(head
->first
);
1043 return rcu_dereference(node
->next
);
1045 EXPORT_SYMBOL(seq_hlist_next_rcu
);
1048 * seq_hlist_start_percpu - start an iteration of a percpu hlist array
1049 * @head: pointer to percpu array of struct hlist_heads
1050 * @cpu: pointer to cpu "cursor"
1051 * @pos: start position of sequence
1053 * Called at seq_file->op->start().
1056 seq_hlist_start_percpu(struct hlist_head __percpu
*head
, int *cpu
, loff_t pos
)
1058 struct hlist_node
*node
;
1060 for_each_possible_cpu(*cpu
) {
1061 hlist_for_each(node
, per_cpu_ptr(head
, *cpu
)) {
1068 EXPORT_SYMBOL(seq_hlist_start_percpu
);
1071 * seq_hlist_next_percpu - move to the next position of the percpu hlist array
1072 * @v: pointer to current hlist_node
1073 * @head: pointer to percpu array of struct hlist_heads
1074 * @cpu: pointer to cpu "cursor"
1075 * @pos: start position of sequence
1077 * Called at seq_file->op->next().
1080 seq_hlist_next_percpu(void *v
, struct hlist_head __percpu
*head
,
1081 int *cpu
, loff_t
*pos
)
1083 struct hlist_node
*node
= v
;
1090 for (*cpu
= cpumask_next(*cpu
, cpu_possible_mask
); *cpu
< nr_cpu_ids
;
1091 *cpu
= cpumask_next(*cpu
, cpu_possible_mask
)) {
1092 struct hlist_head
*bucket
= per_cpu_ptr(head
, *cpu
);
1094 if (!hlist_empty(bucket
))
1095 return bucket
->first
;
1099 EXPORT_SYMBOL(seq_hlist_next_percpu
);
1101 void __init
seq_file_init(void)
1103 seq_file_cache
= KMEM_CACHE(seq_file
, SLAB_ACCOUNT
|SLAB_PANIC
);