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authorAlexey Dobriyan <adobriyan@gmail.com>2009-12-14 18:00:06 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-12-15 08:53:24 -0800
commit0ead0f84e81a41c3e98aeceab04af8ab1bb08d1f (patch)
treeba5d354818d2ec0a8251b3f4a5c9b9bef1092e07 /arch/alpha
parent4614a696bd1c3a9af3a08f0e5874830a85b889d4 (diff)
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 <adobriyan@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/alpha')
-rw-r--r--arch/alpha/kernel/srm_env.c65
1 files changed, 33 insertions, 32 deletions
diff --git a/arch/alpha/kernel/srm_env.c b/arch/alpha/kernel/srm_env.c
index d12af472e1c..dbbf04f9230 100644
--- a/arch/alpha/kernel/srm_env.c
+++ b/arch/alpha/kernel/srm_env.c
@@ -33,6 +33,7 @@
#include <linux/module.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
#include <asm/console.h>
#include <asm/uaccess.h>
#include <asm/machvec.h>
@@ -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,