Commit db23491c authored by Kees Cook's avatar Kees Cook

pstore: Convert "records_list" locking to mutex

The pstorefs internal list lock doesn't need to be a spinlock and will
create problems when trying to access the list in the subsequent patch
that will walk the pstorefs records during pstore_unregister(). Change
this to a mutex to avoid may_sleep() warnings when unregistering devices.

Link: https://lore.kernel.org/lkml/20200506152114.50375-6-keescook@chromium.org/Signed-off-by: default avatarKees Cook <keescook@chromium.org>
parent 47af61ff
......@@ -22,14 +22,13 @@
#include <linux/magic.h>
#include <linux/pstore.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include "internal.h"
#define PSTORE_NAMELEN 64
static DEFINE_SPINLOCK(records_list_lock);
static DEFINE_MUTEX(records_list_lock);
static LIST_HEAD(records_list);
struct pstore_private {
......@@ -192,13 +191,12 @@ static int pstore_unlink(struct inode *dir, struct dentry *dentry)
static void pstore_evict_inode(struct inode *inode)
{
struct pstore_private *p = inode->i_private;
unsigned long flags;
clear_inode(inode);
if (p) {
spin_lock_irqsave(&records_list_lock, flags);
mutex_lock(&records_list_lock);
list_del(&p->list);
spin_unlock_irqrestore(&records_list_lock, flags);
mutex_unlock(&records_list_lock);
free_pstore_private(p);
}
}
......@@ -297,12 +295,11 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record)
int rc = 0;
char name[PSTORE_NAMELEN];
struct pstore_private *private, *pos;
unsigned long flags;
size_t size = record->size + record->ecc_notice_size;
WARN_ON(!inode_is_locked(d_inode(root)));
spin_lock_irqsave(&records_list_lock, flags);
mutex_lock(&records_list_lock);
list_for_each_entry(pos, &records_list, list) {
if (pos->record->type == record->type &&
pos->record->id == record->id &&
......@@ -311,7 +308,7 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record)
break;
}
}
spin_unlock_irqrestore(&records_list_lock, flags);
mutex_unlock(&records_list_lock);
if (rc)
return rc;
......@@ -343,9 +340,9 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record)
d_add(dentry, inode);
spin_lock_irqsave(&records_list_lock, flags);
mutex_lock(&records_list_lock);
list_add(&private->list, &records_list);
spin_unlock_irqrestore(&records_list_lock, flags);
mutex_unlock(&records_list_lock);
return 0;
......
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