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-rw-r--r--fs/proc/base.c45
-rw-r--r--fs/proc/internal.h8
-rw-r--r--fs/proc/proc_sysctl.c69
3 files changed, 100 insertions, 22 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index f1e1927ccd48..719c2e943ea1 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1355,6 +1355,49 @@ static const struct file_operations proc_fault_inject_operations = {
.write = proc_fault_inject_write,
.llseek = generic_file_llseek,
};
+
+static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct task_struct *task;
+ int err;
+ unsigned int n;
+
+ err = kstrtouint_from_user(buf, count, 0, &n);
+ if (err)
+ return err;
+
+ task = get_proc_task(file_inode(file));
+ if (!task)
+ return -ESRCH;
+ WRITE_ONCE(task->fail_nth, n);
+ put_task_struct(task);
+
+ return count;
+}
+
+static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct task_struct *task;
+ char numbuf[PROC_NUMBUF];
+ ssize_t len;
+
+ task = get_proc_task(file_inode(file));
+ if (!task)
+ return -ESRCH;
+ len = snprintf(numbuf, sizeof(numbuf), "%u\n",
+ READ_ONCE(task->fail_nth));
+ len = simple_read_from_buffer(buf, count, ppos, numbuf, len);
+ put_task_struct(task);
+
+ return len;
+}
+
+static const struct file_operations proc_fail_nth_operations = {
+ .read = proc_fail_nth_read,
+ .write = proc_fail_nth_write,
+};
#endif
@@ -2919,6 +2962,7 @@ static const struct pid_entry tgid_base_stuff[] = {
#endif
#ifdef CONFIG_FAULT_INJECTION
REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
+ REG("fail-nth", 0644, proc_fail_nth_operations),
#endif
#ifdef CONFIG_ELF_CORE
REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
@@ -3311,6 +3355,7 @@ static const struct pid_entry tid_base_stuff[] = {
#endif
#ifdef CONFIG_FAULT_INJECTION
REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
+ REG("fail-nth", 0644, proc_fail_nth_operations),
#endif
#ifdef CONFIG_TASK_IO_ACCOUNTING
ONE("io", S_IRUSR, proc_tid_io_accounting),
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index c5ae09b6c726..aa2b89071630 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -51,7 +51,7 @@ struct proc_dir_entry {
spinlock_t pde_unload_lock; /* proc_fops checks and pde_users bumps */
u8 namelen;
char name[];
-};
+} __randomize_layout;
union proc_op {
int (*proc_get_link)(struct dentry *, struct path *);
@@ -67,10 +67,10 @@ struct proc_inode {
struct proc_dir_entry *pde;
struct ctl_table_header *sysctl;
struct ctl_table *sysctl_entry;
- struct list_head sysctl_inodes;
+ struct hlist_node sysctl_inodes;
const struct proc_ns_operations *ns_ops;
struct inode vfs_inode;
-};
+} __randomize_layout;
/*
* General functions
@@ -279,7 +279,7 @@ struct proc_maps_private {
#ifdef CONFIG_NUMA
struct mempolicy *task_mempolicy;
#endif
-};
+} __randomize_layout;
struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode);
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 67985a7233c2..8f479229b349 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -191,7 +191,7 @@ static void init_header(struct ctl_table_header *head,
head->set = set;
head->parent = NULL;
head->node = node;
- INIT_LIST_HEAD(&head->inodes);
+ INIT_HLIST_HEAD(&head->inodes);
if (node) {
struct ctl_table *entry;
for (entry = table; entry->procname; entry++, node++)
@@ -261,25 +261,42 @@ static void unuse_table(struct ctl_table_header *p)
complete(p->unregistering);
}
-/* called under sysctl_lock */
static void proc_sys_prune_dcache(struct ctl_table_header *head)
{
- struct inode *inode, *prev = NULL;
+ struct inode *inode;
struct proc_inode *ei;
+ struct hlist_node *node;
+ struct super_block *sb;
rcu_read_lock();
- list_for_each_entry_rcu(ei, &head->inodes, sysctl_inodes) {
- inode = igrab(&ei->vfs_inode);
- if (inode) {
- rcu_read_unlock();
- iput(prev);
- prev = inode;
- d_prune_aliases(inode);
+ for (;;) {
+ node = hlist_first_rcu(&head->inodes);
+ if (!node)
+ break;
+ ei = hlist_entry(node, struct proc_inode, sysctl_inodes);
+ spin_lock(&sysctl_lock);
+ hlist_del_init_rcu(&ei->sysctl_inodes);
+ spin_unlock(&sysctl_lock);
+
+ inode = &ei->vfs_inode;
+ sb = inode->i_sb;
+ if (!atomic_inc_not_zero(&sb->s_active))
+ continue;
+ inode = igrab(inode);
+ rcu_read_unlock();
+ if (unlikely(!inode)) {
+ deactivate_super(sb);
rcu_read_lock();
+ continue;
}
+
+ d_prune_aliases(inode);
+ iput(inode);
+ deactivate_super(sb);
+
+ rcu_read_lock();
}
rcu_read_unlock();
- iput(prev);
}
/* called under sysctl_lock, will reacquire if has to wait */
@@ -461,7 +478,7 @@ static struct inode *proc_sys_make_inode(struct super_block *sb,
}
ei->sysctl = head;
ei->sysctl_entry = table;
- list_add_rcu(&ei->sysctl_inodes, &head->inodes);
+ hlist_add_head_rcu(&ei->sysctl_inodes, &head->inodes);
head->count++;
spin_unlock(&sysctl_lock);
@@ -489,7 +506,7 @@ out:
void proc_sys_evict_inode(struct inode *inode, struct ctl_table_header *head)
{
spin_lock(&sysctl_lock);
- list_del_rcu(&PROC_I(inode)->sysctl_inodes);
+ hlist_del_init_rcu(&PROC_I(inode)->sysctl_inodes);
if (!--head->count)
kfree_rcu(head, rcu);
spin_unlock(&sysctl_lock);
@@ -1061,16 +1078,30 @@ static int sysctl_err(const char *path, struct ctl_table *table, char *fmt, ...)
return -EINVAL;
}
+static int sysctl_check_table_array(const char *path, struct ctl_table *table)
+{
+ int err = 0;
+
+ if ((table->proc_handler == proc_douintvec) ||
+ (table->proc_handler == proc_douintvec_minmax)) {
+ if (table->maxlen != sizeof(unsigned int))
+ err |= sysctl_err(path, table, "array now allowed");
+ }
+
+ return err;
+}
+
static int sysctl_check_table(const char *path, struct ctl_table *table)
{
int err = 0;
for (; table->procname; table++) {
if (table->child)
- err = sysctl_err(path, table, "Not a file");
+ err |= sysctl_err(path, table, "Not a file");
if ((table->proc_handler == proc_dostring) ||
(table->proc_handler == proc_dointvec) ||
(table->proc_handler == proc_douintvec) ||
+ (table->proc_handler == proc_douintvec_minmax) ||
(table->proc_handler == proc_dointvec_minmax) ||
(table->proc_handler == proc_dointvec_jiffies) ||
(table->proc_handler == proc_dointvec_userhz_jiffies) ||
@@ -1078,15 +1109,17 @@ static int sysctl_check_table(const char *path, struct ctl_table *table)
(table->proc_handler == proc_doulongvec_minmax) ||
(table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) {
if (!table->data)
- err = sysctl_err(path, table, "No data");
+ err |= sysctl_err(path, table, "No data");
if (!table->maxlen)
- err = sysctl_err(path, table, "No maxlen");
+ err |= sysctl_err(path, table, "No maxlen");
+ else
+ err |= sysctl_check_table_array(path, table);
}
if (!table->proc_handler)
- err = sysctl_err(path, table, "No proc_handler");
+ err |= sysctl_err(path, table, "No proc_handler");
if ((table->mode & (S_IRUGO|S_IWUGO)) != table->mode)
- err = sysctl_err(path, table, "bogus .mode 0%o",
+ err |= sysctl_err(path, table, "bogus .mode 0%o",
table->mode);
}
return err;
generated by cgit v1.2.3 (git 2.39.1) at 2025-02-06 14:44:07 +0000