![Alexey Dobriyan](/assets/img/avatar_default.png)
Short enough reads from /proc/irq/*/smp_affinity return -EINVAL for no good reason. This became noticed with NR_CPUS=4096 patches, when length of printed representation of cpumask becase 1152, but cat(1) continued to read with 1024-byte chunks. bitmap_scnprintf() in good faith fills buffer, returns 1023, check returns -EINVAL. Fix it by switching to seq_file, so handler will just fill buffer and doesn't care about offsets, length, filling EOF and all this crap. For that add seq_bitmap(), and wrappers around it -- seq_cpumask() and seq_nodemask(). Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Paul Jackson <pj@sgi.com> Cc: Mike Travis <travis@sgi.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
83 lines
2.3 KiB
C
83 lines
2.3 KiB
C
#ifndef _LINUX_SEQ_FILE_H
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#define _LINUX_SEQ_FILE_H
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#include <linux/types.h>
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#include <linux/string.h>
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#include <linux/mutex.h>
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#include <linux/cpumask.h>
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#include <linux/nodemask.h>
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struct seq_operations;
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struct file;
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struct path;
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struct inode;
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struct dentry;
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struct seq_file {
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char *buf;
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size_t size;
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size_t from;
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size_t count;
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loff_t index;
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u64 version;
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struct mutex lock;
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const struct seq_operations *op;
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void *private;
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};
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struct seq_operations {
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void * (*start) (struct seq_file *m, loff_t *pos);
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void (*stop) (struct seq_file *m, void *v);
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void * (*next) (struct seq_file *m, void *v, loff_t *pos);
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int (*show) (struct seq_file *m, void *v);
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};
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#define SEQ_SKIP 1
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int seq_open(struct file *, const struct seq_operations *);
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ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
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loff_t seq_lseek(struct file *, loff_t, int);
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int seq_release(struct inode *, struct file *);
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int seq_escape(struct seq_file *, const char *, const char *);
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int seq_putc(struct seq_file *m, char c);
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int seq_puts(struct seq_file *m, const char *s);
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int seq_printf(struct seq_file *, const char *, ...)
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__attribute__ ((format (printf,2,3)));
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int seq_path(struct seq_file *, struct path *, char *);
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int seq_dentry(struct seq_file *, struct dentry *, char *);
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int seq_path_root(struct seq_file *m, struct path *path, struct path *root,
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char *esc);
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int seq_bitmap(struct seq_file *m, unsigned long *bits, unsigned int nr_bits);
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static inline int seq_cpumask(struct seq_file *m, cpumask_t *mask)
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{
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return seq_bitmap(m, mask->bits, NR_CPUS);
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}
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static inline int seq_nodemask(struct seq_file *m, nodemask_t *mask)
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{
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return seq_bitmap(m, mask->bits, MAX_NUMNODES);
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}
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int single_open(struct file *, int (*)(struct seq_file *, void *), void *);
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int single_release(struct inode *, struct file *);
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void *__seq_open_private(struct file *, const struct seq_operations *, int);
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int seq_open_private(struct file *, const struct seq_operations *, int);
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int seq_release_private(struct inode *, struct file *);
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#define SEQ_START_TOKEN ((void *)1)
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/*
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* Helpers for iteration over list_head-s in seq_files
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*/
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extern struct list_head *seq_list_start(struct list_head *head,
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loff_t pos);
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extern struct list_head *seq_list_start_head(struct list_head *head,
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loff_t pos);
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extern struct list_head *seq_list_next(void *v, struct list_head *head,
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loff_t *ppos);
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#endif
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