From 2bd30b8dc75b823dd7bbef9d7bc68e1fd7ecee5c Mon Sep 17 00:00:00 2001 From: Sang-Heon Jeon Date: Mon, 24 Aug 2026 01:18:14 +0900 Subject: coccinelle: alloc_cast: drop removed allocators - pci_alloc_consistent() and pci_zalloc_consistent() were removed by commit 7968778914e5 ("PCI: Remove the deprecated "pci-dma-compat.h" API") - kmem_alloc() was removed by commit f078d4ea8276 ("xfs: convert kmem_alloc() to kmalloc()") - kmem_zalloc() was removed by commit 10634530f7ba ("xfs: convert kmem_zalloc() to kzalloc()") - kmem_zone_alloc() and kmem_zone_zalloc() were removed by commit bae633a4a283 ("xfs: remove xfs_zone_{alloc,zalloc} helpers") So drop them from the rules. No functional change. Signed-off-by: Sang-Heon Jeon Signed-off-by: Julia Lawall --- fs/proc/fd.c | 407 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 407 insertions(+) create mode 100644 fs/proc/fd.c (limited to 'fs/proc/fd.c') diff --git a/fs/proc/fd.c b/fs/proc/fd.c new file mode 100644 index 000000000..0f9a1556f --- /dev/null +++ b/fs/proc/fd.c @@ -0,0 +1,407 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "../mount.h" +#include "internal.h" +#include "fd.h" + +static int seq_show(struct seq_file *m, void *v) +{ + struct files_struct *files = NULL; + int f_flags = 0, ret = -ENOENT; + struct file *file = NULL; + struct task_struct *task; + + task = get_proc_task(m->private); + if (!task) + return -ENOENT; + + task_lock(task); + files = task->files; + if (files) { + unsigned int fd = proc_fd(m->private); + + spin_lock(&files->file_lock); + file = files_lookup_fd_locked(files, fd); + if (file) { + f_flags = file->f_flags; + if (close_on_exec(fd, files)) + f_flags |= O_CLOEXEC; + + get_file(file); + ret = 0; + } + spin_unlock(&files->file_lock); + } + task_unlock(task); + put_task_struct(task); + + if (ret) + return ret; + + seq_printf(m, "pos:\t%lli\nflags:\t0%o\nmnt_id:\t%i\nino:\t%llu\n", + (long long)file->f_pos, f_flags, + real_mount(file->f_path.mnt)->mnt_id, + file_inode(file)->i_ino); + + /* show_fd_locks() never dereferences files, so a stale value is safe */ + show_fd_locks(m, file, files); + if (seq_has_overflowed(m)) + goto out; + + if (file->f_op->show_fdinfo) + file->f_op->show_fdinfo(m, file); + +out: + fput(file); + return 0; +} + +static int seq_fdinfo_open(struct inode *inode, struct file *file) +{ + return single_open(file, seq_show, inode); +} + +/* + * Shared /proc/pid/fdinfo and /proc/pid/fdinfo/fd permission helper to ensure + * that the current task has PTRACE_MODE_READ in addition to the normal + * POSIX-like checks. + */ +static int proc_fdinfo_permission(struct mnt_idmap *idmap, struct inode *inode, + int mask) +{ + bool allowed = false; + struct task_struct *task = get_proc_task(inode); + + if (!task) + return -ESRCH; + + allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); + put_task_struct(task); + + if (!allowed) + return -EACCES; + + return generic_permission(idmap, inode, mask); +} + +static const struct inode_operations proc_fdinfo_file_inode_operations = { + .permission = proc_fdinfo_permission, + .setattr = proc_nochmod_setattr, +}; + +static const struct file_operations proc_fdinfo_file_operations = { + .open = seq_fdinfo_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static bool tid_fd_mode(struct task_struct *task, unsigned fd, fmode_t *mode) +{ + struct file *file; + + file = fget_task(task, fd); + if (file) { + *mode = file->f_mode; + fput(file); + } + 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 inode *dir, const struct qstr *name, + struct dentry *dentry, unsigned int flags) +{ + struct task_struct *task; + struct inode *inode; + unsigned int fd; + + if (flags & LOOKUP_RCU) + return -ECHILD; + + inode = d_inode(dentry); + task = get_proc_task(inode); + fd = proc_fd(inode); + + if (task) { + 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); + } + return 0; +} + +static const struct dentry_operations tid_fd_dentry_operations = { + .d_revalidate = tid_fd_revalidate, + .d_delete = pid_delete_dentry, +}; + +static int proc_fd_link(struct dentry *dentry, struct path *path, + struct task_struct *task) +{ + int ret = -ENOENT; + unsigned int fd = proc_fd(d_inode(dentry)); + struct file *fd_file; + + fd_file = fget_task(task, fd); + if (fd_file) { + *path = fd_file->f_path; + path_get(&fd_file->f_path); + ret = 0; + fput(fd_file); + } + + return ret; +} + +struct fd_data { + fmode_t mode; + unsigned fd; +}; + +static struct dentry *proc_fd_instantiate(struct dentry *dentry, + struct task_struct *task, const void *ptr) +{ + const struct fd_data *data = ptr; + struct proc_inode *ei; + struct inode *inode; + + inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK); + if (!inode) + return ERR_PTR(-ENOENT); + + ei = PROC_I(inode); + 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); + + return proc_splice_unmountable(inode, dentry, + &tid_fd_dentry_operations); +} + +static struct dentry *proc_lookupfd_common(struct inode *dir, + struct dentry *dentry, + instantiate_t instantiate) +{ + struct task_struct *task = get_proc_task(dir); + struct fd_data data = {.fd = name_to_int(&dentry->d_name)}; + struct dentry *result = ERR_PTR(-ENOENT); + + if (!task) + goto out_no_task; + if (data.fd == ~0U) + goto out; + if (!tid_fd_mode(task, data.fd, &data.mode)) + goto out; + + result = instantiate(dentry, task, &data); +out: + put_task_struct(task); +out_no_task: + return result; +} + +static int proc_readfd_common(struct file *file, struct dir_context *ctx, + instantiate_t instantiate) +{ + struct task_struct *p = get_proc_task(file_inode(file)); + unsigned int fd; + + if (!p) + return -ENOENT; + + if (!dir_emit_dots(file, ctx)) + goto out; + + for (fd = ctx->pos - 2;; fd++) { + struct file *f; + struct fd_data data; + char name[10 + 1]; + unsigned int len; + + f = fget_task_next(p, &fd); + ctx->pos = fd + 2LL; + if (!f) + break; + data.mode = f->f_mode; + fput(f); + data.fd = fd; + + len = snprintf(name, sizeof(name), "%u", fd); + if (!proc_fill_cache(file, ctx, + name, len, instantiate, p, + &data)) + break; + cond_resched(); + } +out: + put_task_struct(p); + return 0; +} + +static int proc_readfd_count(struct inode *inode, loff_t *count) +{ + struct task_struct *p = get_proc_task(inode); + struct fdtable *fdt; + + if (!p) + return -ENOENT; + + task_lock(p); + if (p->files) { + rcu_read_lock(); + + fdt = files_fdtable(p->files); + *count = bitmap_weight(fdt->open_fds, fdt->max_fds); + + rcu_read_unlock(); + } + task_unlock(p); + + put_task_struct(p); + + return 0; +} + +static int proc_fd_iterate(struct file *file, struct dir_context *ctx) +{ + return proc_readfd_common(file, ctx, proc_fd_instantiate); +} + +const struct file_operations proc_fd_operations = { + .read = generic_read_dir, + .iterate_shared = proc_fd_iterate, + .llseek = generic_file_llseek, +}; + +static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, + unsigned int flags) +{ + return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); +} + +/* + * /proc/pid/fd needs a special permission handler so that a process can still + * access /proc/self/fd after it has executed a setuid(). + */ +int proc_fd_permission(struct mnt_idmap *idmap, + struct inode *inode, int mask) +{ + struct task_struct *p; + int rv; + + rv = generic_permission(&nop_mnt_idmap, inode, mask); + if (rv == 0) + return rv; + + rcu_read_lock(); + p = pid_task(proc_pid(inode), PIDTYPE_PID); + if (p && same_thread_group(p, current)) + rv = 0; + rcu_read_unlock(); + + return rv; +} + +static int proc_fd_getattr(struct mnt_idmap *idmap, + const struct path *path, struct kstat *stat, + u32 request_mask, unsigned int query_flags) +{ + struct inode *inode = d_inode(path->dentry); + + generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat); + return proc_readfd_count(inode, &stat->size); +} + +const struct inode_operations proc_fd_inode_operations = { + .lookup = proc_lookupfd, + .permission = proc_fd_permission, + .getattr = proc_fd_getattr, + .setattr = proc_nochmod_setattr, +}; + +static struct dentry *proc_fdinfo_instantiate(struct dentry *dentry, + struct task_struct *task, const void *ptr) +{ + const struct fd_data *data = ptr; + struct proc_inode *ei; + struct inode *inode; + + inode = proc_pid_make_inode(dentry->d_sb, task, S_IFREG | S_IRUGO); + if (!inode) + return ERR_PTR(-ENOENT); + + ei = PROC_I(inode); + ei->fd = data->fd; + + inode->i_op = &proc_fdinfo_file_inode_operations; + + inode->i_fop = &proc_fdinfo_file_operations; + tid_fd_update_inode(task, inode, 0); + + return proc_splice_unmountable(inode, dentry, + &tid_fd_dentry_operations); +} + +static struct dentry * +proc_lookupfdinfo(struct inode *dir, struct dentry *dentry, unsigned int flags) +{ + return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); +} + +static int proc_fdinfo_iterate(struct file *file, struct dir_context *ctx) +{ + return proc_readfd_common(file, ctx, + proc_fdinfo_instantiate); +} + +const struct inode_operations proc_fdinfo_inode_operations = { + .lookup = proc_lookupfdinfo, + .permission = proc_fdinfo_permission, + .setattr = proc_nochmod_setattr, +}; + +const struct file_operations proc_fdinfo_operations = { + .read = generic_read_dir, + .iterate_shared = proc_fdinfo_iterate, + .llseek = generic_file_llseek, +}; -- cgit v1.3.1