From 0ead0f84e81a41c3e98aeceab04af8ab1bb08d1f Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Mon, 14 Dec 2009 18:00:06 -0800 Subject: [PATCH] alpha: convert srm code to seq_file Convert code away from ->read_proc/->write_proc interfaces. Switch to proc_create()/proc_create_data() which make addition of proc entries reliable wrt NULL ->proc_fops, NULL ->data and so on. Problem with ->read_proc et al is described here commit 786d7e1612f0b0adb6046f19b906609e4fe8b1ba "Fix rmmod/read/write races in /proc entries" Signed-off-by: Alexey Dobriyan Cc: Richard Henderson Cc: Ivan Kokshaysky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/alpha/kernel/srm_env.c | 65 +++++++++++++++++++++++---------------------- 1 file changed, 33 insertions(+), 32 deletions(-) diff --git a/arch/alpha/kernel/srm_env.c b/arch/alpha/kernel/srm_env.c index d12af47..dbbf04f 100644 --- a/arch/alpha/kernel/srm_env.c +++ b/arch/alpha/kernel/srm_env.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include #include @@ -79,42 +80,41 @@ static srm_env_t srm_named_entries[] = { static srm_env_t srm_numbered_entries[256]; -static int -srm_env_read(char *page, char **start, off_t off, int count, int *eof, - void *data) +static int srm_env_proc_show(struct seq_file *m, void *v) { - int nbytes; unsigned long ret; srm_env_t *entry; + char *page; - if (off != 0) { - *eof = 1; - return 0; - } + entry = (srm_env_t *)m->private; + page = (char *)__get_free_page(GFP_USER); + if (!page) + return -ENOMEM; - entry = (srm_env_t *) data; - ret = callback_getenv(entry->id, page, count); + ret = callback_getenv(entry->id, page, PAGE_SIZE); if ((ret >> 61) == 0) { - nbytes = (int) ret; - *eof = 1; + seq_write(m, page, ret); + ret = 0; } else - nbytes = -EFAULT; + ret = -EFAULT; + free_page((unsigned long)page); + return ret; +} - return nbytes; +static int srm_env_proc_open(struct inode *inode, struct file *file) +{ + return single_open(file, srm_env_proc_show, PDE(inode)->data); } -static int -srm_env_write(struct file *file, const char __user *buffer, unsigned long count, - void *data) +static ssize_t srm_env_proc_write(struct file *file, const char __user *buffer, + size_t count, loff_t *pos) { int res; - srm_env_t *entry; + srm_env_t *entry = PDE(file->f_path.dentry->d_inode)->data; char *buf = (char *) __get_free_page(GFP_USER); unsigned long ret1, ret2; - entry = (srm_env_t *) data; - if (!buf) return -ENOMEM; @@ -140,6 +140,15 @@ srm_env_write(struct file *file, const char __user *buffer, unsigned long count, return res; } +static const struct file_operations srm_env_proc_fops = { + .owner = THIS_MODULE, + .open = srm_env_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, + .write = srm_env_proc_write, +}; + static void srm_env_cleanup(void) { @@ -245,15 +254,10 @@ srm_env_init(void) */ entry = srm_named_entries; while (entry->name && entry->id) { - entry->proc_entry = create_proc_entry(entry->name, - 0644, named_dir); + entry->proc_entry = proc_create_data(entry->name, 0644, named_dir, + &srm_env_proc_fops, entry); if (!entry->proc_entry) goto cleanup; - - entry->proc_entry->data = (void *) entry; - entry->proc_entry->read_proc = srm_env_read; - entry->proc_entry->write_proc = srm_env_write; - entry++; } @@ -264,15 +268,12 @@ srm_env_init(void) entry = &srm_numbered_entries[var_num]; entry->name = number[var_num]; - entry->proc_entry = create_proc_entry(entry->name, - 0644, numbered_dir); + entry->proc_entry = proc_create_data(entry->name, 0644, numbered_dir, + &srm_env_proc_fops, entry); if (!entry->proc_entry) goto cleanup; entry->id = var_num; - entry->proc_entry->data = (void *) entry; - entry->proc_entry->read_proc = srm_env_read; - entry->proc_entry->write_proc = srm_env_write; } printk(KERN_INFO "%s: version %s loaded successfully\n", NAME, -- 2.7.4