Commit faf145d6 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'exec-for-v5.11' of... 

Merge branch 'exec-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull execve updates from Eric Biederman:
 "This set of changes ultimately fixes the interaction of posix file
  lock and exec. Fundamentally most of the change is just moving where
  unshare_files is called during exec, and tweaking the users of
  files_struct so that the count of files_struct is not unnecessarily
  played with.

  Along the way fcheck and related helpers were renamed to more
  accurately reflect what they do.

  There were also many other small changes that fell out, as this is the
  first time in a long time much of this code has been touched.

  Benchmarks haven't turned up any practical issues but Al Viro has
  observed a possibility for a lot of pounding on task_lock. So I have
  some changes in progress to convert put_files_struct to always rcu
  free files_struct. That wasn't ready for the merge window so that will
  have to wait until next time"

* 'exec-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits)
  exec: Move io_uring_task_cancel after the point of no return
  coredump: Document coredump code exclusively used by cell spufs
  file: Remove get_files_struct
  file: Rename __close_fd_get_file close_fd_get_file
  file: Replace ksys_close with close_fd
  file: Rename __close_fd to close_fd and remove the files parameter
  file: Merge __alloc_fd into alloc_fd
  file: In f_dupfd read RLIMIT_NOFILE once.
  file: Merge __fd_install into fd_install
  proc/fd: In fdinfo seq_show don't use get_files_struct
  bpf/task_iter: In task_file_seq_get_next use task_lookup_next_fd_rcu
  proc/fd: In proc_readfd_common use task_lookup_next_fd_rcu
  file: Implement task_lookup_next_fd_rcu
  kcmp: In get_file_raw_ptr use task_lookup_fd_rcu
  proc/fd: In tid_fd_mode use task_lookup_fd_rcu
  file: Implement task_lookup_fd_rcu
  file: Rename fcheck lookup_fd_rcu
  file: Replace fcheck_files with files_lookup_fd_rcu
  file: Factor files_lookup_fd_locked out of fcheck_files
  file: Rename __fcheck_files to files_lookup_fd_raw
  ...
parents 6febd8be 9ee1206d

Documentation/filesystems/files.rst

+4 −4
Original line number Diff line number Diff line
@@ -62,7 +62,7 @@ the fdtable structure - 
   be held.



4. To look up the file structure given an fd, a reader

   must use either fcheck() or fcheck_files() APIs. These

   must use either lookup_fd_rcu() or files_lookup_fd_rcu() APIs. These

   take care of barrier requirements due to lock-free lookup.



   An example::
@@ -70,7 +70,7 @@ the fdtable structure - 
	struct file *file;



	rcu_read_lock();

	file = fcheck(fd);

	file = lookup_fd_rcu(fd);

	if (file) {

		...

	}
@@ -84,7 +84,7 @@ the fdtable structure - 
   on ->f_count::



	rcu_read_lock();

	file = fcheck_files(files, fd);

	file = files_lookup_fd_rcu(files, fd);

	if (file) {

		if (atomic_long_inc_not_zero(&file->f_count))

			*fput_needed = 1;
@@ -104,7 +104,7 @@ the fdtable structure - 
   lock-free, they must be installed using rcu_assign_pointer()

   API. If they are looked up lock-free, rcu_dereference()

   must be used. However it is advisable to use files_fdtable()

   and fcheck()/fcheck_files() which take care of these issues.

   and lookup_fd_rcu()/files_lookup_fd_rcu() which take care of these issues.



7. While updating, the fdtable pointer must be looked up while

   holding files->file_lock. If ->file_lock is dropped, then

arch/powerpc/platforms/cell/spufs/coredump.c

+1 −1
Original line number Diff line number Diff line
@@ -74,7 +74,7 @@ static struct spu_context *coredump_next_context(int *fd) 
	*fd = n - 1;



	rcu_read_lock();

	file = fcheck(*fd);

	file = lookup_fd_rcu(*fd);

	ctx = SPUFS_I(file_inode(file))->i_ctx;

	get_spu_context(ctx);

	rcu_read_unlock();

drivers/android/binder.c

+1 −1
Original line number Diff line number Diff line
@@ -1836,7 +1836,7 @@ static void binder_deferred_fd_close(int fd) 
	if (!twcb)

		return;

	init_task_work(&twcb->twork, binder_do_fd_close);

	__close_fd_get_file(fd, &twcb->file);

	close_fd_get_file(fd, &twcb->file);

	if (twcb->file) {

		filp_close(twcb->file, current->files);

		task_work_add(current, &twcb->twork, TWA_RESUME);

fs/autofs/dev-ioctl.c

+3 −2
Original line number Diff line number Diff line
@@ -4,9 +4,10 @@ 
 * Copyright 2008 Ian Kent <raven@themaw.net>

 */



#include <linux/module.h>

#include <linux/miscdevice.h>

#include <linux/compat.h>

#include <linux/syscalls.h>

#include <linux/fdtable.h>

#include <linux/magic.h>

#include <linux/nospec.h>
@@ -289,7 +290,7 @@ static int autofs_dev_ioctl_closemount(struct file *fp, 
				       struct autofs_sb_info *sbi,

				       struct autofs_dev_ioctl *param)

{

	return ksys_close(param->ioctlfd);

	return close_fd(param->ioctlfd);

}



/*

fs/binfmt_elf.c

+2 −0
Original line number Diff line number Diff line
@@ -2198,6 +2198,7 @@ static int elf_core_dump(struct coredump_params *cprm) 
	{

		size_t sz = get_note_info_size(&info);



		/* For cell spufs */

		sz += elf_coredump_extra_notes_size();



		phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
@@ -2261,6 +2262,7 @@ static int elf_core_dump(struct coredump_params *cprm) 
	if (!write_note_info(&info, cprm))

		goto end_coredump;



	/* For cell spufs */

	if (elf_coredump_extra_notes_write(cprm))

		goto end_coredump;

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