memfd_create() handles all of its logic in a single function. Some of
the logic in the function is also somewhat contrived (i.e. copying the
memfd name from userpace).
This series aims to cleanup memfd_create() by splitting out the logic
into helper functions, and simplifying the memfd name copying to make
the code easier to follow.
This has no intended functional changes.
Note: to apply this series over mm-unstable, please revert v3 of
the series:
commit 3147192ed457 ("mm/memfd: use strncpy_from_user() to read memfd name")
commit 1212f60db000 ("mm/memfd: refactor and cleanup the logic in memfd_create()")
The base commit from mm-unstable that I used was:
commit 0703fa3785f1 ("mm: remove PageTransTail()")
Thank you Alice and Lorenzo for reviewing v3 of this series and for your
feedback!
Changes from v3 ==> v4:
- Removed an unnecessary comment at the end of memfd_create() that I
added.
- Added Alice and Lorenzo's "Reviewed-by" tags to both patches in
the series.
- Rebased on top of the latest commit of the mm-unstable branch as
mentioned above.
Changes from v2 ==> v3:
- Removed namespacing from the new helper functions names.
- Updated names for helper functions to better describe what they do.
- Changed the argument to the flags sanitization function to be a
pointer to not discard changes to the flags.
- Restored original ordering of how the fd and file structure were
allocated.
- Simplified the constant used for allocating the buffer for the memfd
name to NAME_MAX.
- Updated a comment about the return value of strncpy_from_user().
- Added Alice's "Reviewed-by" tag to the last patch in the series.
Changes from v1 ==> v2:
- Rebased on top of the mm-unstable branch instead of Linus' master
branch. Base commit on mm-unstable: ca95745c20ad ("mm/memmap: prevent
double scanning of memmap by kmemleak").
Links:
v1: https://lore.kernel.org/all/20250102230658.1112261-1-isaacmanjarres@xxxxxxxxxx/#t
v2: https://lore.kernel.org/all/20250107184804.4074147-1-isaacmanjarres@xxxxxxxxxx/
v3: https://lore.kernel.org/all/20250109185908.1006310-1-isaacmanjarres@xxxxxxxxxx/
Isaac J. Manjarres (2):
mm/memfd: Refactor and cleanup the logic in memfd_create()
mm/memfd: Use strncpy_from_user() to read memfd name
mm/memfd.c | 95 +++++++++++++++++++++++++++++++++++-------------------
1 file changed, 61 insertions(+), 34 deletions(-)
--
2.47.1.613.gc27f4b7a9f-goog
