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Diffstat (limited to 'fs/proc/fd.c')
-rw-r--r--fs/proc/fd.c138
1 files changed, 73 insertions, 65 deletions
diff --git a/fs/proc/fd.c b/fs/proc/fd.c
index 6b80cd1e419a..05b9893e9a22 100644
--- a/fs/proc/fd.c
+++ b/fs/proc/fd.c
@@ -81,9 +81,41 @@ static const struct file_operations proc_fdinfo_file_operations = {
.release = single_release,
};
+static bool tid_fd_mode(struct task_struct *task, unsigned fd, fmode_t *mode)
+{
+ struct files_struct *files = get_files_struct(task);
+ struct file *file;
+
+ if (!files)
+ return false;
+
+ rcu_read_lock();
+ file = fcheck_files(files, fd);
+ if (file)
+ *mode = file->f_mode;
+ rcu_read_unlock();
+ put_files_struct(files);
+ return !!file;
+}
+
+static void tid_fd_update_inode(struct task_struct *task, struct inode *inode,
+ fmode_t f_mode)
+{
+ task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
+
+ if (S_ISLNK(inode->i_mode)) {
+ unsigned i_mode = S_IFLNK;
+ if (f_mode & FMODE_READ)
+ i_mode |= S_IRUSR | S_IXUSR;
+ if (f_mode & FMODE_WRITE)
+ i_mode |= S_IWUSR | S_IXUSR;
+ inode->i_mode = i_mode;
+ }
+ security_task_to_inode(task, inode);
+}
+
static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
{
- struct files_struct *files;
struct task_struct *task;
struct inode *inode;
unsigned int fd;
@@ -96,35 +128,11 @@ static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
fd = proc_fd(inode);
if (task) {
- files = get_files_struct(task);
- if (files) {
- struct file *file;
-
- rcu_read_lock();
- file = fcheck_files(files, fd);
- if (file) {
- unsigned f_mode = file->f_mode;
-
- rcu_read_unlock();
- put_files_struct(files);
-
- task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
-
- if (S_ISLNK(inode->i_mode)) {
- unsigned i_mode = S_IFLNK;
- if (f_mode & FMODE_READ)
- i_mode |= S_IRUSR | S_IXUSR;
- if (f_mode & FMODE_WRITE)
- i_mode |= S_IWUSR | S_IXUSR;
- inode->i_mode = i_mode;
- }
-
- security_task_to_inode(task, inode);
- put_task_struct(task);
- return 1;
- }
- rcu_read_unlock();
- put_files_struct(files);
+ fmode_t f_mode;
+ if (tid_fd_mode(task, fd, &f_mode)) {
+ tid_fd_update_inode(task, inode, f_mode);
+ put_task_struct(task);
+ return 1;
}
put_task_struct(task);
}
@@ -166,34 +174,33 @@ static int proc_fd_link(struct dentry *dentry, struct path *path)
return ret;
}
-static int
-proc_fd_instantiate(struct inode *dir, struct dentry *dentry,
- struct task_struct *task, const void *ptr)
+struct fd_data {
+ fmode_t mode;
+ unsigned fd;
+};
+
+static struct dentry *proc_fd_instantiate(struct dentry *dentry,
+ struct task_struct *task, const void *ptr)
{
- unsigned fd = (unsigned long)ptr;
+ const struct fd_data *data = ptr;
struct proc_inode *ei;
struct inode *inode;
- inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK);
+ inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK);
if (!inode)
- goto out;
+ return ERR_PTR(-ENOENT);
ei = PROC_I(inode);
- ei->fd = fd;
+ ei->fd = data->fd;
inode->i_op = &proc_pid_link_inode_operations;
inode->i_size = 64;
ei->op.proc_get_link = proc_fd_link;
+ tid_fd_update_inode(task, inode, data->mode);
d_set_d_op(dentry, &tid_fd_dentry_operations);
- d_add(dentry, inode);
-
- /* Close the race of the process dying before we return the dentry */
- if (tid_fd_revalidate(dentry, 0))
- return 0;
- out:
- return -ENOENT;
+ return d_splice_alias(inode, dentry);
}
static struct dentry *proc_lookupfd_common(struct inode *dir,
@@ -201,19 +208,21 @@ static struct dentry *proc_lookupfd_common(struct inode *dir,
instantiate_t instantiate)
{
struct task_struct *task = get_proc_task(dir);
- int result = -ENOENT;
- unsigned fd = name_to_int(&dentry->d_name);
+ struct fd_data data = {.fd = name_to_int(&dentry->d_name)};
+ struct dentry *result = ERR_PTR(-ENOENT);
if (!task)
goto out_no_task;
- if (fd == ~0U)
+ if (data.fd == ~0U)
+ goto out;
+ if (!tid_fd_mode(task, data.fd, &data.mode))
goto out;
- result = instantiate(dir, dentry, task, (void *)(unsigned long)fd);
+ result = instantiate(dentry, task, &data);
out:
put_task_struct(task);
out_no_task:
- return ERR_PTR(result);
+ return result;
}
static int proc_readfd_common(struct file *file, struct dir_context *ctx,
@@ -236,17 +245,22 @@ static int proc_readfd_common(struct file *file, struct dir_context *ctx,
for (fd = ctx->pos - 2;
fd < files_fdtable(files)->max_fds;
fd++, ctx->pos++) {
+ struct file *f;
+ struct fd_data data;
char name[10 + 1];
int len;
- if (!fcheck_files(files, fd))
+ f = fcheck_files(files, fd);
+ if (!f)
continue;
+ data.mode = f->f_mode;
rcu_read_unlock();
+ data.fd = fd;
len = snprintf(name, sizeof(name), "%u", fd);
if (!proc_fill_cache(file, ctx,
name, len, instantiate, p,
- (void *)(unsigned long)fd))
+ &data))
goto out_fd_loop;
cond_resched();
rcu_read_lock();
@@ -304,31 +318,25 @@ const struct inode_operations proc_fd_inode_operations = {
.setattr = proc_setattr,
};
-static int
-proc_fdinfo_instantiate(struct inode *dir, struct dentry *dentry,
- struct task_struct *task, const void *ptr)
+static struct dentry *proc_fdinfo_instantiate(struct dentry *dentry,
+ struct task_struct *task, const void *ptr)
{
- unsigned fd = (unsigned long)ptr;
+ const struct fd_data *data = ptr;
struct proc_inode *ei;
struct inode *inode;
- inode = proc_pid_make_inode(dir->i_sb, task, S_IFREG | S_IRUSR);
+ inode = proc_pid_make_inode(dentry->d_sb, task, S_IFREG | S_IRUSR);
if (!inode)
- goto out;
+ return ERR_PTR(-ENOENT);
ei = PROC_I(inode);
- ei->fd = fd;
+ ei->fd = data->fd;
inode->i_fop = &proc_fdinfo_file_operations;
+ tid_fd_update_inode(task, inode, 0);
d_set_d_op(dentry, &tid_fd_dentry_operations);
- d_add(dentry, inode);
-
- /* Close the race of the process dying before we return the dentry */
- if (tid_fd_revalidate(dentry, 0))
- return 0;
- out:
- return -ENOENT;
+ return d_splice_alias(inode, dentry);
}
static struct dentry *
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-19 22:25:18 +0100