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Merge branch 'remove-ksys-mount-dup' of git://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux

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Pull ksys_mount() and ksys_dup() removal from Dominik Brodowski:
 "This small series replaces all in-kernel calls to the
  userspace-focused ksys_mount() and ksys_dup() with calls to
  kernel-centric functions:

  For each replacement of ksys_mount() with do_mount(), one needs to
  verify that the first and third parameter (char *dev_name, char *type)
  are strings allocated in kernelspace and that the fifth parameter
  (void *data) is either NULL or refers to a full page (only occurence
  in init/do_mounts.c::do_mount_root()). The second and fourth
  parameters (char *dir_name, unsigned long flags) are passed by
  ksys_mount() to do_mount() unchanged, and therefore do not require
  particular care.

  Moreover, instead of pretending to be userspace, the opening of
  /dev/console as stdin/stdout/stderr can be implemented using in-kernel
  functions as well. Thereby, ksys_dup() can be removed for good"

[ This doesn't get rid of the special "kernel init runs with KERNEL_DS"
  case, but it at least removes _some_ of the users of "treat kernel
  pointers as user pointers for our magical init sequence".

  One day we'll hopefully be rid of it all, and can initialize our
  init_thread addr_limit to USER_DS.    - Linus ]

* 'remove-ksys-mount-dup' of git://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux:
  fs: remove ksys_dup()
  init: unify opening /dev/console as stdin/stdout/stderr
  init: use do_mount() instead of ksys_mount()
  initrd: use do_mount() instead of ksys_mount()
  devtmpfs: use do_mount() instead of ksys_mount()
This commit is contained in:
Linus Torvalds
2019-12-15 11:36:12 -08:00
parent 510c978899 8243186f0c
commit 2e6d304515
9 changed files with 63 additions and 41 deletions
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6
drivers/base/devtmpfs.c
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@@ -359,7 +359,7 @@ static int handle_remove(const char *nodename, struct device *dev)
* If configured, or requested by the commandline, devtmpfs will be
* auto-mounted after the kernel mounted the root filesystem.
*/
int devtmpfs_mount(const char *mntdir)
int devtmpfs_mount(void)
{
int err;
@@ -369,7 +369,7 @@ int devtmpfs_mount(const char *mntdir)
if (!thread)
return 0;
err = ksys_mount("devtmpfs", mntdir, "devtmpfs", MS_SILENT, NULL);
err = do_mount("devtmpfs", "dev", "devtmpfs", MS_SILENT, NULL);
if (err)
printk(KERN_INFO "devtmpfs: error mounting %i\n", err);
else
@@ -394,7 +394,7 @@ static int devtmpfsd(void *p)
*err = ksys_unshare(CLONE_NEWNS);
if (*err)
goto out;
*err = ksys_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, NULL);
*err = do_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, NULL);
if (*err)
goto out;
ksys_chdir("/.."); /* will traverse into overmounted root */