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![Stephen Rothwell](/assets/img/avatar_default.png)
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
232 lines
5 KiB
C
232 lines
5 KiB
C
/*
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* proc_devtree.c - handles /proc/device-tree
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*
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* Copyright 1997 Paul Mackerras
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*/
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#include <linux/errno.h>
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#include <linux/time.h>
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#include <linux/proc_fs.h>
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#include <linux/stat.h>
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#include <linux/string.h>
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#include <asm/prom.h>
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#include <asm/uaccess.h>
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#ifndef HAVE_ARCH_DEVTREE_FIXUPS
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static inline void set_node_proc_entry(struct device_node *np,
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struct proc_dir_entry *de)
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{
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}
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#endif
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static struct proc_dir_entry *proc_device_tree;
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/*
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* Supply data on a read from /proc/device-tree/node/property.
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*/
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static int property_read_proc(char *page, char **start, off_t off,
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int count, int *eof, void *data)
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{
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struct property *pp = data;
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int n;
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if (off >= pp->length) {
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*eof = 1;
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return 0;
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}
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n = pp->length - off;
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if (n > count)
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n = count;
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else
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*eof = 1;
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memcpy(page, (char *)pp->value + off, n);
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*start = page;
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return n;
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}
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/*
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* For a node with a name like "gc@10", we make symlinks called "gc"
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* and "@10" to it.
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*/
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/*
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* Add a property to a node
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*/
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static struct proc_dir_entry *
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__proc_device_tree_add_prop(struct proc_dir_entry *de, struct property *pp,
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const char *name)
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{
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struct proc_dir_entry *ent;
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/*
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* Unfortunately proc_register puts each new entry
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* at the beginning of the list. So we rearrange them.
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*/
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ent = create_proc_read_entry(name,
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strncmp(name, "security-", 9)
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? S_IRUGO : S_IRUSR, de,
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property_read_proc, pp);
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if (ent == NULL)
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return NULL;
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if (!strncmp(name, "security-", 9))
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ent->size = 0; /* don't leak number of password chars */
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else
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ent->size = pp->length;
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return ent;
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}
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void proc_device_tree_add_prop(struct proc_dir_entry *pde, struct property *prop)
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{
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__proc_device_tree_add_prop(pde, prop, prop->name);
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}
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void proc_device_tree_remove_prop(struct proc_dir_entry *pde,
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struct property *prop)
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{
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remove_proc_entry(prop->name, pde);
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}
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void proc_device_tree_update_prop(struct proc_dir_entry *pde,
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struct property *newprop,
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struct property *oldprop)
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{
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struct proc_dir_entry *ent;
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for (ent = pde->subdir; ent != NULL; ent = ent->next)
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if (ent->data == oldprop)
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break;
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if (ent == NULL) {
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printk(KERN_WARNING "device-tree: property \"%s\" "
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" does not exist\n", oldprop->name);
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} else {
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ent->data = newprop;
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ent->size = newprop->length;
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}
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}
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/*
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* Various dodgy firmware might give us nodes and/or properties with
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* conflicting names. That's generally ok, except for exporting via /proc,
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* so munge names here to ensure they're unique.
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*/
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static int duplicate_name(struct proc_dir_entry *de, const char *name)
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{
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struct proc_dir_entry *ent;
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int found = 0;
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spin_lock(&proc_subdir_lock);
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for (ent = de->subdir; ent != NULL; ent = ent->next) {
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if (strcmp(ent->name, name) == 0) {
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found = 1;
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break;
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}
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}
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spin_unlock(&proc_subdir_lock);
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return found;
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}
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static const char *fixup_name(struct device_node *np, struct proc_dir_entry *de,
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const char *name)
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{
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char *fixed_name;
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int fixup_len = strlen(name) + 2 + 1; /* name + #x + \0 */
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int i = 1, size;
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realloc:
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fixed_name = kmalloc(fixup_len, GFP_KERNEL);
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if (fixed_name == NULL) {
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printk(KERN_ERR "device-tree: Out of memory trying to fixup "
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"name \"%s\"\n", name);
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return name;
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}
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retry:
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size = snprintf(fixed_name, fixup_len, "%s#%d", name, i);
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size++; /* account for NULL */
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if (size > fixup_len) {
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/* We ran out of space, free and reallocate. */
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kfree(fixed_name);
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fixup_len = size;
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goto realloc;
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}
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if (duplicate_name(de, fixed_name)) {
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/* Multiple duplicates. Retry with a different offset. */
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i++;
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goto retry;
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}
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printk(KERN_WARNING "device-tree: Duplicate name in %s, "
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"renamed to \"%s\"\n", np->full_name, fixed_name);
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return fixed_name;
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}
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/*
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* Process a node, adding entries for its children and its properties.
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*/
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void proc_device_tree_add_node(struct device_node *np,
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struct proc_dir_entry *de)
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{
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struct property *pp;
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struct proc_dir_entry *ent;
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struct device_node *child;
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const char *p;
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set_node_proc_entry(np, de);
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for (child = NULL; (child = of_get_next_child(np, child));) {
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/* Use everything after the last slash, or the full name */
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p = strrchr(child->full_name, '/');
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if (!p)
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p = child->full_name;
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else
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++p;
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if (duplicate_name(de, p))
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p = fixup_name(np, de, p);
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ent = proc_mkdir(p, de);
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if (ent == 0)
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break;
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proc_device_tree_add_node(child, ent);
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}
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of_node_put(child);
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for (pp = np->properties; pp != 0; pp = pp->next) {
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p = pp->name;
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if (duplicate_name(de, p))
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p = fixup_name(np, de, p);
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ent = __proc_device_tree_add_prop(de, pp, p);
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if (ent == 0)
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break;
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}
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}
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/*
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* Called on initialization to set up the /proc/device-tree subtree
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*/
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void proc_device_tree_init(void)
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{
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struct device_node *root;
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if ( !have_of )
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return;
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proc_device_tree = proc_mkdir("device-tree", NULL);
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if (proc_device_tree == 0)
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return;
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root = of_find_node_by_path("/");
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if (root == 0) {
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printk(KERN_ERR "/proc/device-tree: can't find root\n");
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return;
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}
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proc_device_tree_add_node(root, proc_device_tree);
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of_node_put(root);
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}
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