summaryrefslogtreecommitdiffstats
path: root/fs/proc
diff options
context:
space:
mode:
Diffstat (limited to 'fs/proc')
-rw-r--r--fs/proc/base.c355
1 files changed, 355 insertions, 0 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index e31d95055c67..4d755fed3ecb 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -83,6 +83,7 @@
#include <linux/pid_namespace.h>
#include <linux/fs_struct.h>
#include <linux/slab.h>
+#include <linux/flex_array.h>
#ifdef CONFIG_HARDWALL
#include <asm/hardwall.h>
#endif
@@ -134,6 +135,8 @@ struct pid_entry {
NULL, &proc_single_file_operations, \
{ .proc_show = show } )
+static int proc_fd_permission(struct inode *inode, int mask);
+
/*
* Count the number of hardlinks for the pid_entry table, excluding the .
* and .. links.
@@ -2046,6 +2049,355 @@ static const struct file_operations proc_fd_operations = {
.llseek = default_llseek,
};
+#ifdef CONFIG_CHECKPOINT_RESTORE
+
+/*
+ * dname_to_vma_addr - maps a dentry name into two unsigned longs
+ * which represent vma start and end addresses.
+ */
+static int dname_to_vma_addr(struct dentry *dentry,
+ unsigned long *start, unsigned long *end)
+{
+ if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int map_files_d_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+ unsigned long vm_start, vm_end;
+ bool exact_vma_exists = false;
+ struct mm_struct *mm = NULL;
+ struct task_struct *task;
+ const struct cred *cred;
+ struct inode *inode;
+ int status = 0;
+
+ if (nd && nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ if (!capable(CAP_SYS_ADMIN)) {
+ status = -EACCES;
+ goto out_notask;
+ }
+
+ inode = dentry->d_inode;
+ task = get_proc_task(inode);
+ if (!task)
+ goto out_notask;
+
+ if (!ptrace_may_access(task, PTRACE_MODE_READ))
+ goto out;
+
+ mm = get_task_mm(task);
+ if (!mm)
+ goto out;
+
+ if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
+ down_read(&mm->mmap_sem);
+ exact_vma_exists = !!find_exact_vma(mm, vm_start, vm_end);
+ up_read(&mm->mmap_sem);
+ }
+
+ mmput(mm);
+
+ if (exact_vma_exists) {
+ if (task_dumpable(task)) {
+ rcu_read_lock();
+ cred = __task_cred(task);
+ inode->i_uid = cred->euid;
+ inode->i_gid = cred->egid;
+ rcu_read_unlock();
+ } else {
+ inode->i_uid = 0;
+ inode->i_gid = 0;
+ }
+ security_task_to_inode(task, inode);
+ status = 1;
+ }
+
+out:
+ put_task_struct(task);
+
+out_notask:
+ if (status <= 0)
+ d_drop(dentry);
+
+ return status;
+}
+
+static const struct dentry_operations tid_map_files_dentry_operations = {
+ .d_revalidate = map_files_d_revalidate,
+ .d_delete = pid_delete_dentry,
+};
+
+static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
+{
+ unsigned long vm_start, vm_end;
+ struct vm_area_struct *vma;
+ struct task_struct *task;
+ struct mm_struct *mm;
+ int rc;
+
+ rc = -ENOENT;
+ task = get_proc_task(dentry->d_inode);
+ if (!task)
+ goto out;
+
+ mm = get_task_mm(task);
+ put_task_struct(task);
+ if (!mm)
+ goto out;
+
+ rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
+ if (rc)
+ goto out_mmput;
+
+ down_read(&mm->mmap_sem);
+ vma = find_exact_vma(mm, vm_start, vm_end);
+ if (vma && vma->vm_file) {
+ *path = vma->vm_file->f_path;
+ path_get(path);
+ rc = 0;
+ }
+ up_read(&mm->mmap_sem);
+
+out_mmput:
+ mmput(mm);
+out:
+ return rc;
+}
+
+struct map_files_info {
+ struct file *file;
+ unsigned long len;
+ unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
+};
+
+static struct dentry *
+proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
+ struct task_struct *task, const void *ptr)
+{
+ const struct file *file = ptr;
+ struct proc_inode *ei;
+ struct inode *inode;
+
+ if (!file)
+ return ERR_PTR(-ENOENT);
+
+ inode = proc_pid_make_inode(dir->i_sb, task);
+ if (!inode)
+ return ERR_PTR(-ENOENT);
+
+ ei = PROC_I(inode);
+ ei->op.proc_get_link = proc_map_files_get_link;
+
+ inode->i_op = &proc_pid_link_inode_operations;
+ inode->i_size = 64;
+ inode->i_mode = S_IFLNK;
+
+ if (file->f_mode & FMODE_READ)
+ inode->i_mode |= S_IRUSR;
+ if (file->f_mode & FMODE_WRITE)
+ inode->i_mode |= S_IWUSR;
+
+ d_set_d_op(dentry, &tid_map_files_dentry_operations);
+ d_add(dentry, inode);
+
+ return NULL;
+}
+
+static struct dentry *proc_map_files_lookup(struct inode *dir,
+ struct dentry *dentry, struct nameidata *nd)
+{
+ unsigned long vm_start, vm_end;
+ struct vm_area_struct *vma;
+ struct task_struct *task;
+ struct dentry *result;
+ struct mm_struct *mm;
+
+ result = ERR_PTR(-EACCES);
+ if (!capable(CAP_SYS_ADMIN))
+ goto out;
+
+ result = ERR_PTR(-ENOENT);
+ task = get_proc_task(dir);
+ if (!task)
+ goto out;
+
+ result = ERR_PTR(-EACCES);
+ if (lock_trace(task))
+ goto out_put_task;
+
+ result = ERR_PTR(-ENOENT);
+ if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
+ goto out_unlock;
+
+ mm = get_task_mm(task);
+ if (!mm)
+ goto out_unlock;
+
+ down_read(&mm->mmap_sem);
+ vma = find_exact_vma(mm, vm_start, vm_end);
+ if (!vma)
+ goto out_no_vma;
+
+ result = proc_map_files_instantiate(dir, dentry, task, vma->vm_file);
+
+out_no_vma:
+ up_read(&mm->mmap_sem);
+ mmput(mm);
+out_unlock:
+ unlock_trace(task);
+out_put_task:
+ put_task_struct(task);
+out:
+ return result;
+}
+
+static const struct inode_operations proc_map_files_inode_operations = {
+ .lookup = proc_map_files_lookup,
+ .permission = proc_fd_permission,
+ .setattr = proc_setattr,
+};
+
+static int
+proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
+{
+ struct dentry *dentry = filp->f_path.dentry;
+ struct inode *inode = dentry->d_inode;
+ struct vm_area_struct *vma;
+ struct task_struct *task;
+ struct mm_struct *mm;
+ ino_t ino;
+ int ret;
+
+ ret = -EACCES;
+ if (!capable(CAP_SYS_ADMIN))
+ goto out;
+
+ ret = -ENOENT;
+ task = get_proc_task(inode);
+ if (!task)
+ goto out;
+
+ ret = -EACCES;
+ if (lock_trace(task))
+ goto out_put_task;
+
+ ret = 0;
+ switch (filp->f_pos) {
+ case 0:
+ ino = inode->i_ino;
+ if (filldir(dirent, ".", 1, 0, ino, DT_DIR) < 0)
+ goto out_unlock;
+ filp->f_pos++;
+ case 1:
+ ino = parent_ino(dentry);
+ if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
+ goto out_unlock;
+ filp->f_pos++;
+ default:
+ {
+ unsigned long nr_files, pos, i;
+ struct flex_array *fa = NULL;
+ struct map_files_info info;
+ struct map_files_info *p;
+
+ mm = get_task_mm(task);
+ if (!mm)
+ goto out_unlock;
+ down_read(&mm->mmap_sem);
+
+ nr_files = 0;
+
+ /*
+ * We need two passes here:
+ *
+ * 1) Collect vmas of mapped files with mmap_sem taken
+ * 2) Release mmap_sem and instantiate entries
+ *
+ * otherwise we get lockdep complained, since filldir()
+ * routine might require mmap_sem taken in might_fault().
+ */
+
+ for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
+ if (vma->vm_file && ++pos > filp->f_pos)
+ nr_files++;
+ }
+
+ if (nr_files) {
+ fa = flex_array_alloc(sizeof(info), nr_files,
+ GFP_KERNEL);
+ if (!fa || flex_array_prealloc(fa, 0, nr_files,
+ GFP_KERNEL)) {
+ ret = -ENOMEM;
+ if (fa)
+ flex_array_free(fa);
+ up_read(&mm->mmap_sem);
+ mmput(mm);
+ goto out_unlock;
+ }
+ for (i = 0, vma = mm->mmap, pos = 2; vma;
+ vma = vma->vm_next) {
+ if (!vma->vm_file)
+ continue;
+ if (++pos <= filp->f_pos)
+ continue;
+
+ get_file(vma->vm_file);
+ info.file = vma->vm_file;
+ info.len = snprintf(info.name,
+ sizeof(info.name), "%lx-%lx",
+ vma->vm_start, vma->vm_end);
+ if (flex_array_put(fa, i++, &info, GFP_KERNEL))
+ BUG();
+ }
+ }
+ up_read(&mm->mmap_sem);
+
+ for (i = 0; i < nr_files; i++) {
+ p = flex_array_get(fa, i);
+ ret = proc_fill_cache(filp, dirent, filldir,
+ p->name, p->len,
+ proc_map_files_instantiate,
+ task, p->file);
+ if (ret)
+ break;
+ filp->f_pos++;
+ fput(p->file);
+ }
+ for (; i < nr_files; i++) {
+ /*
+ * In case of error don't forget
+ * to put rest of file refs.
+ */
+ p = flex_array_get(fa, i);
+ fput(p->file);
+ }
+ if (fa)
+ flex_array_free(fa);
+ mmput(mm);
+ }
+ }
+
+out_unlock:
+ unlock_trace(task);
+out_put_task:
+ put_task_struct(task);
+out:
+ return ret;
+}
+
+static const struct file_operations proc_map_files_operations = {
+ .read = generic_read_dir,
+ .readdir = proc_map_files_readdir,
+ .llseek = default_llseek,
+};
+
+#endif /* CONFIG_CHECKPOINT_RESTORE */
+
/*
* /proc/pid/fd needs a special permission handler so that a process can still
* access /proc/self/fd after it has executed a setuid().
@@ -2661,6 +3013,9 @@ static const struct inode_operations proc_task_inode_operations;
static const struct pid_entry tgid_base_stuff[] = {
DIR("task", S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
DIR("fd", S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
+#ifdef CONFIG_CHECKPOINT_RESTORE
+ DIR("map_files", S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
+#endif
DIR("fdinfo", S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
DIR("ns", S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
#ifdef CONFIG_NET
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-17 08:31:58 +0000