1 files changed, 193 insertions, 39 deletions

diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index 4e32edc8f506..d6ebf0596510 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -1,34 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _LINUX_SEQ_FILE_H
 #define _LINUX_SEQ_FILE_H
 
 #include <linux/types.h>
 #include <linux/string.h>
+#include <linux/string_helpers.h>
 #include <linux/bug.h>
 #include <linux/mutex.h>
-#include <linux/cpumask.h>
 #include <linux/nodemask.h>
+#include <linux/fs.h>
+#include <linux/cred.h>
 
 struct seq_operations;
-struct file;
-struct path;
-struct inode;
-struct dentry;
-struct user_namespace;
 
 struct seq_file {
 	char *buf;
 	size_t size;
 	size_t from;
 	size_t count;
+	size_t pad_until;
 	loff_t index;
 	loff_t read_pos;
-	u64 version;
 	struct mutex lock;
 	const struct seq_operations *op;
 	int poll_event;
-#ifdef CONFIG_USER_NS
-	struct user_namespace *user_ns;
-#endif
+	const struct file *file;
 	void *private;
 };
 
@@ -42,6 +38,21 @@ struct seq_operations {
 #define SEQ_SKIP 1
 
 /**
+ * seq_has_overflowed - check if the buffer has overflowed
+ * @m: the seq_file handle
+ *
+ * seq_files have a buffer which may overflow. When this happens a larger
+ * buffer is reallocated and all the data will be printed again.
+ * The overflow state is true when m->count == m->size.
+ *
+ * Returns true if the buffer received more than it can hold.
+ */
+static inline bool seq_has_overflowed(struct seq_file *m)
+{
+	return m->count == m->size;
+}
+
+/**
  * seq_get_buf - get buffer to write arbitrary data to
  * @m: the seq_file handle
  * @bufp: the beginning of the buffer is stored here
@@ -79,70 +90,208 @@ static inline void seq_commit(struct seq_file *m, int num)
 	}
 }
 
+/**
+ * seq_setwidth - set padding width
+ * @m: the seq_file handle
+ * @size: the max number of bytes to pad.
+ *
+ * Call seq_setwidth() for setting max width, then call seq_printf() etc. and
+ * finally call seq_pad() to pad the remaining bytes.
+ */
+static inline void seq_setwidth(struct seq_file *m, size_t size)
+{
+	m->pad_until = m->count + size;
+}
+void seq_pad(struct seq_file *m, char c);
+
 char *mangle_path(char *s, const char *p, const char *esc);
 int seq_open(struct file *, const struct seq_operations *);
 ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
+ssize_t seq_read_iter(struct kiocb *iocb, struct iov_iter *iter);
 loff_t seq_lseek(struct file *, loff_t, int);
 int seq_release(struct inode *, struct file *);
-int seq_escape(struct seq_file *, const char *, const char *);
-int seq_putc(struct seq_file *m, char c);
-int seq_puts(struct seq_file *m, const char *s);
 int seq_write(struct seq_file *seq, const void *data, size_t len);
 
-__printf(2, 3) int seq_printf(struct seq_file *, const char *, ...);
-__printf(2, 0) int seq_vprintf(struct seq_file *, const char *, va_list args);
+__printf(2, 0)
+void seq_vprintf(struct seq_file *m, const char *fmt, va_list args);
+__printf(2, 3)
+void seq_printf(struct seq_file *m, const char *fmt, ...);
+void seq_putc(struct seq_file *m, char c);
+void __seq_puts(struct seq_file *m, const char *s);
 
-int seq_path(struct seq_file *, const struct path *, const char *);
-int seq_dentry(struct seq_file *, struct dentry *, const char *);
-int seq_path_root(struct seq_file *m, const struct path *path,
-		  const struct path *root, const char *esc);
-int seq_bitmap(struct seq_file *m, const unsigned long *bits,
-				   unsigned int nr_bits);
-static inline int seq_cpumask(struct seq_file *m, const struct cpumask *mask)
+static __always_inline void seq_puts(struct seq_file *m, const char *s)
 {
-	return seq_bitmap(m, cpumask_bits(mask), nr_cpu_ids);
+	if (!__builtin_constant_p(*s))
+		__seq_puts(m, s);
+	else if (s[0] && !s[1])
+		seq_putc(m, s[0]);
+	else
+		seq_write(m, s, __builtin_strlen(s));
 }
 
-static inline int seq_nodemask(struct seq_file *m, nodemask_t *mask)
-{
-	return seq_bitmap(m, mask->bits, MAX_NUMNODES);
-}
+void seq_put_decimal_ull_width(struct seq_file *m, const char *delimiter,
+			       unsigned long long num, unsigned int width);
+void seq_put_decimal_ull(struct seq_file *m, const char *delimiter,
+			 unsigned long long num);
+void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num);
+void seq_put_hex_ll(struct seq_file *m, const char *delimiter,
+		    unsigned long long v, unsigned int width);
 
-int seq_bitmap_list(struct seq_file *m, const unsigned long *bits,
-		unsigned int nr_bits);
+void seq_escape_mem(struct seq_file *m, const char *src, size_t len,
+		    unsigned int flags, const char *esc);
 
-static inline int seq_cpumask_list(struct seq_file *m,
-				   const struct cpumask *mask)
+static inline void seq_escape_str(struct seq_file *m, const char *src,
+				  unsigned int flags, const char *esc)
 {
-	return seq_bitmap_list(m, cpumask_bits(mask), nr_cpu_ids);
+	seq_escape_mem(m, src, strlen(src), flags, esc);
 }
 
-static inline int seq_nodemask_list(struct seq_file *m, nodemask_t *mask)
+/**
+ * seq_escape - print string into buffer, escaping some characters
+ * @m: target buffer
+ * @s: NULL-terminated string
+ * @esc: set of characters that need escaping
+ *
+ * Puts string into buffer, replacing each occurrence of character from
+ * @esc with usual octal escape.
+ *
+ * Use seq_has_overflowed() to check for errors.
+ */
+static inline void seq_escape(struct seq_file *m, const char *s, const char *esc)
 {
-	return seq_bitmap_list(m, mask->bits, MAX_NUMNODES);
+	seq_escape_str(m, s, ESCAPE_OCTAL, esc);
 }
 
+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);
+
+int seq_path(struct seq_file *, const struct path *, const char *);
+int seq_file_path(struct seq_file *, struct file *, const char *);
+int seq_dentry(struct seq_file *, struct dentry *, const char *);
+int seq_path_root(struct seq_file *m, const struct path *path,
+		  const struct path *root, const char *esc);
+
+void *single_start(struct seq_file *, loff_t *);
 int single_open(struct file *, int (*)(struct seq_file *, void *), void *);
 int single_open_size(struct file *, int (*)(struct seq_file *, void *), void *, size_t);
 int single_release(struct inode *, struct file *);
 void *__seq_open_private(struct file *, const struct seq_operations *, int);
 int seq_open_private(struct file *, const struct seq_operations *, int);
 int seq_release_private(struct inode *, struct file *);
-int seq_put_decimal_ull(struct seq_file *m, char delimiter,
-			unsigned long long num);
-int seq_put_decimal_ll(struct seq_file *m, char delimiter,
-			long long num);
+
+#ifdef CONFIG_BINARY_PRINTF
+__printf(2, 0)
+void seq_bprintf(struct seq_file *m, const char *f, const u32 *binary);
+#endif
+
+#define DEFINE_SEQ_ATTRIBUTE(__name)					\
+static int __name ## _open(struct inode *inode, struct file *file)	\
+{									\
+	int ret = seq_open(file, &__name ## _sops);			\
+	if (!ret && inode->i_private) {					\
+		struct seq_file *seq_f = file->private_data;		\
+		seq_f->private = inode->i_private;			\
+	}								\
+	return ret;							\
+}									\
+									\
+static const struct file_operations __name ## _fops = {			\
+	.owner		= THIS_MODULE,					\
+	.open		= __name ## _open,				\
+	.read		= seq_read,					\
+	.llseek		= seq_lseek,					\
+	.release	= seq_release,					\
+}
+
+#define DEFINE_SHOW_ATTRIBUTE(__name)					\
+static int __name ## _open(struct inode *inode, struct file *file)	\
+{									\
+	return single_open(file, __name ## _show, inode->i_private);	\
+}									\
+									\
+static const struct file_operations __name ## _fops = {			\
+	.owner		= THIS_MODULE,					\
+	.open		= __name ## _open,				\
+	.read		= seq_read,					\
+	.llseek		= seq_lseek,					\
+	.release	= single_release,				\
+}
+
+#define DEFINE_SHOW_STORE_ATTRIBUTE(__name)				\
+static int __name ## _open(struct inode *inode, struct file *file)	\
+{									\
+	return single_open(file, __name ## _show, inode->i_private);	\
+}									\
+									\
+static const struct file_operations __name ## _fops = {			\
+	.owner		= THIS_MODULE,					\
+	.open		= __name ## _open,				\
+	.read		= seq_read,					\
+	.write		= __name ## _write,				\
+	.llseek		= seq_lseek,					\
+	.release	= single_release,				\
+}
+
+#define DEFINE_PROC_SHOW_ATTRIBUTE(__name)				\
+static int __name ## _open(struct inode *inode, struct file *file)	\
+{									\
+	return single_open(file, __name ## _show, pde_data(inode));	\
+}									\
+									\
+static const struct proc_ops __name ## _proc_ops = {			\
+	.proc_open	= __name ## _open,				\
+	.proc_read	= seq_read,					\
+	.proc_lseek	= seq_lseek,					\
+	.proc_release	= single_release,				\
+}
 
 static inline struct user_namespace *seq_user_ns(struct seq_file *seq)
 {
 #ifdef CONFIG_USER_NS
-	return seq->user_ns;
+	return seq->file->f_cred->user_ns;
 #else
 	extern struct user_namespace init_user_ns;
 	return &init_user_ns;
 #endif
 }
 
+/**
+ * seq_show_options - display mount options with appropriate escapes.
+ * @m: the seq_file handle
+ * @name: the mount option name
+ * @value: the mount option name's value, can be NULL
+ */
+static inline void seq_show_option(struct seq_file *m, const char *name,
+				   const char *value)
+{
+	seq_putc(m, ',');
+	seq_escape(m, name, ",= \t\n\\");
+	if (value) {
+		seq_putc(m, '=');
+		seq_escape(m, value, ", \t\n\\");
+	}
+}
+
+/**
+ * seq_show_option_n - display mount options with appropriate escapes
+ *		       where @value must be a specific length (i.e.
+ *		       not NUL-terminated).
+ * @m: the seq_file handle
+ * @name: the mount option name
+ * @value: the mount option name's value, cannot be NULL
+ * @length: the exact length of @value to display, must be constant expression
+ *
+ * This is a macro since this uses "length" to define the size of the
+ * stack buffer.
+ */
+#define seq_show_option_n(m, name, value, length) {	\
+	char val_buf[length + 1];			\
+	memcpy(val_buf, value, length);			\
+	val_buf[length] = '\0';				\
+	seq_show_option(m, name, val_buf);		\
+}
+
 #define SEQ_START_TOKEN ((void *)1)
 /*
  * Helpers for iteration over list_head-s in seq_files
@@ -155,6 +304,10 @@ extern struct list_head *seq_list_start_head(struct list_head *head,
 extern struct list_head *seq_list_next(void *v, struct list_head *head,
 		loff_t *ppos);
 
+extern struct list_head *seq_list_start_rcu(struct list_head *head, loff_t pos);
+extern struct list_head *seq_list_start_head_rcu(struct list_head *head, loff_t pos);
+extern struct list_head *seq_list_next_rcu(void *v, struct list_head *head, loff_t *ppos);
+
 /*
  * Helpers for iteration over hlist_head-s in seq_files
  */
@@ -179,4 +332,5 @@ extern struct hlist_node *seq_hlist_start_percpu(struct hlist_head __percpu *hea
 
 extern struct hlist_node *seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, int *cpu, loff_t *pos);
 
+void seq_file_init(void);
 #endif