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[v5,00/18] of: overlay: validation checks, subsequent fixes

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Series of: overlay: validation checks, subsequent fixes | expand

Message

Frank Rowand Oct. 18, 2018, 10:46 p.m. UTC
From: Frank Rowand <frank.rowand@sony.com>

Add checks to (1) overlay apply process and (2) memory freeing
triggered by overlay release.  The checks are intended to detect
possible memory leaks and invalid overlays.

The checks revealed bugs in existing code.  Fixed the bugs.

While fixing bugs, noted other issues, which are fixed in
separate patches.

*****  Powerpc folks: I was not able to test the patches that
*****  directly impact Powerpc systems that use dynamic
*****  devicetree.  Please review that code carefully and
*****  test.  The specific patches are: 03/16, 04/16, 07/16

FPGA folks:

  I made the validation checks that should result in an
  invalid live devicetree report "ERROR" and cause the overlay apply
  to fail.

  I made the memory leak validation tests report "WARNING" and allow
  the overlay apply to complete successfully.  Please let me know
  if you encounter the warnings.  There are at least two paths
  forward to deal with the cases that trigger the warning: (1) change
  the warning to an error and fail the overlay apply, or (2) find a
  way to detect the potential memory leaks and free the memory
  appropriately.

ALL people:

  The validations do _not_ address another major concern I have with
  releasing overlays, which is use after free errors.

Changes since v4:
  - 01/18: make error message format consistent, error first, path last
  - 09/18: create of_prop_val_eq() and change open code to use it
  - 09/18: remove extra blank lines

Changes since v3:
  - 01/18: Add expected value of refcount for destroy cset entry error.  Also
    explain the cause of the error.

  - 09/18: for errors of an overlay changing the value of #size-cells or
    #address-cells, return -EINVAL so that overlay apply will fail
  - 09/18: for errors of an overlay changing the value of #size-cells or
    #address-cells, make the message more direct.
    Old message:
      OF: overlay: ERROR: overlay and/or live tree #size-cells invalid in node /soc/base_fpga_region
    New message:
      OF: overlay: ERROR: changing value of /soc/base_fpga_region/#size-cells not allowed

  - 13/18: Update patch comment header to state that this patch modifies the
    previous patch to not return immediately on fragment error and
    explain this is not a performance issue.
  - 13/18: remove redundant "overlay" from two error messages.  "OF: overlay:"
    is already present in pr_fmt()

Changes since v2:

  - 13/18: Use continue to reduce indentation in find_dup_cset_node_entry()
    and find_dup_cset_prop()

Changes since v1:

  - move patch 16/16 to 17/18
  - move patch 15/16 to 18/18
  - new patch 15/18
  - new patch 16/18

  - 05/18: add_changeset_node() header comment: incorrect comment for @target

  - 18/18: add same fix for of_parse_phandle_with_args()
  - 18/18: add same fix for of_parse_phandle_with_args_map()


*** BLURB HERE ***

Frank Rowand (18):
  of: overlay: add tests to validate kfrees from overlay removal
  of: overlay: add missing of_node_put() after add new node to changeset
  of: overlay: add missing of_node_get() in __of_attach_node_sysfs
  powerpc/pseries: add of_node_put() in dlpar_detach_node()
  of: overlay: use prop add changeset entry for property in new nodes
  of: overlay: do not duplicate properties from overlay for new nodes
  of: dynamic: change type of of_{at,de}tach_node() to void
  of: overlay: reorder fields in struct fragment
  of: overlay: validate overlay properties #address-cells and
    #size-cells
  of: overlay: make all pr_debug() and pr_err() messages unique
  of: overlay: test case of two fragments adding same node
  of: overlay: check prevents multiple fragments add or delete same node
  of: overlay: check prevents multiple fragments touching same property
  of: unittest: remove unused of_unittest_apply_overlay() argument
  of: overlay: set node fields from properties when add new overlay node
  of: unittest: allow base devicetree to have symbol metadata
  of: unittest: find overlays[] entry by name instead of index
  of: unittest: initialize args before calling of_*parse_*()

 arch/powerpc/platforms/pseries/dlpar.c             |  15 +-
 arch/powerpc/platforms/pseries/reconfig.c          |   6 +-
 drivers/of/dynamic.c                               |  68 +++--
 drivers/of/kobj.c                                  |   4 +-
 drivers/of/overlay.c                               | 292 ++++++++++++++++-----
 drivers/of/unittest-data/Makefile                  |   2 +
 .../of/unittest-data/overlay_bad_add_dup_node.dts  |  28 ++
 .../of/unittest-data/overlay_bad_add_dup_prop.dts  |  24 ++
 drivers/of/unittest-data/overlay_base.dts          |   1 +
 drivers/of/unittest.c                              |  96 +++++--
 include/linux/of.h                                 |  25 +-
 11 files changed, 439 insertions(+), 122 deletions(-)
 create mode 100644 drivers/of/unittest-data/overlay_bad_add_dup_node.dts
 create mode 100644 drivers/of/unittest-data/overlay_bad_add_dup_prop.dts

Comments

Frank Rowand Oct. 19, 2018, 5 a.m. UTC | #1
On 10/18/18 15:46, frowand.list@gmail.com wrote:
> From: Frank Rowand <frank.rowand@sony.com>
> 
> Add checks to (1) overlay apply process and (2) memory freeing
> triggered by overlay release.  The checks are intended to detect
> possible memory leaks and invalid overlays.
> 
> The checks revealed bugs in existing code.  Fixed the bugs.
> 
> While fixing bugs, noted other issues, which are fixed in
> separate patches.


git version of the series:


git://git.kernel.org/pub/scm/linux/kernel/git/frowand/linux.git

$ git checkout v4.19-rc1--kfree_validate--v5

$ git log --oneline v4.19-rc1..
62e8f28bb14b of: unittest: initialize args before calling of_*parse_*()
cc8b630f0c7f of: unittest: find overlays[] entry by name instead of index
b80a8e974e0f of: unittest: allow base devicetree to have symbol metadata
bbcd6ead8e36 of: overlay: set node fields from properties when add new overlay node
e02d06f99646 of: unittest: remove unused of_unittest_apply_overlay() argument
484ba7f7eb4a of: overlay: check prevents multiple fragments touching same property
4640b81a605b of: overlay: check prevents multiple fragments add or delete same node
698f942ee230 of: overlay: test case of two fragments adding same node
5fe758e00f1f of: overlay: make all pr_debug() and pr_err() messages unique
868c6f70eed5 of: overlay: validate overlay properties #address-cells and #size-cells
06bc44ce477f of: overlay: reorder fields in struct fragment
584f4537377c of: dynamic: change type of of_{at,de}tach_node() to void
54f30ea3bf65 of: overlay: do not duplicate properties from overlay for new nodes
ad4180c300fc of: overlay: use prop add changeset entry for property in new nodes
b1bdca739700 powerpc/pseries: add of_node_put() in dlpar_detach_node()
8e0290d5cb62 of: overlay: add missing of_node_get() in __of_attach_node_sysfs
93e221495a9f of: overlay: add missing of_node_put() after add new node to changeset
86043f08e539 of: overlay: add tests to validate kfrees from overlay removal
Alan Tull Oct. 22, 2018, 9:24 p.m. UTC | #2
On Thu, Oct 18, 2018 at 5:48 PM <frowand.list@gmail.com> wrote:
>
> From: Frank Rowand <frank.rowand@sony.com>
>
> Add checks to (1) overlay apply process and (2) memory freeing
> triggered by overlay release.  The checks are intended to detect
> possible memory leaks and invalid overlays.

I've tested v5, nothing new to report.

Alan

>
> The checks revealed bugs in existing code.  Fixed the bugs.
>
> While fixing bugs, noted other issues, which are fixed in
> separate patches.
>
> *****  Powerpc folks: I was not able to test the patches that
> *****  directly impact Powerpc systems that use dynamic
> *****  devicetree.  Please review that code carefully and
> *****  test.  The specific patches are: 03/16, 04/16, 07/16
>
> FPGA folks:
>
>   I made the validation checks that should result in an
>   invalid live devicetree report "ERROR" and cause the overlay apply
>   to fail.
>
>   I made the memory leak validation tests report "WARNING" and allow
>   the overlay apply to complete successfully.  Please let me know
>   if you encounter the warnings.  There are at least two paths
>   forward to deal with the cases that trigger the warning: (1) change
>   the warning to an error and fail the overlay apply, or (2) find a
>   way to detect the potential memory leaks and free the memory
>   appropriately.
>
> ALL people:
>
>   The validations do _not_ address another major concern I have with
>   releasing overlays, which is use after free errors.
>
> Changes since v4:
>   - 01/18: make error message format consistent, error first, path last
>   - 09/18: create of_prop_val_eq() and change open code to use it
>   - 09/18: remove extra blank lines
>
> Changes since v3:
>   - 01/18: Add expected value of refcount for destroy cset entry error.  Also
>     explain the cause of the error.
>
>   - 09/18: for errors of an overlay changing the value of #size-cells or
>     #address-cells, return -EINVAL so that overlay apply will fail
>   - 09/18: for errors of an overlay changing the value of #size-cells or
>     #address-cells, make the message more direct.
>     Old message:
>       OF: overlay: ERROR: overlay and/or live tree #size-cells invalid in node /soc/base_fpga_region
>     New message:
>       OF: overlay: ERROR: changing value of /soc/base_fpga_region/#size-cells not allowed
>
>   - 13/18: Update patch comment header to state that this patch modifies the
>     previous patch to not return immediately on fragment error and
>     explain this is not a performance issue.
>   - 13/18: remove redundant "overlay" from two error messages.  "OF: overlay:"
>     is already present in pr_fmt()
>
> Changes since v2:
>
>   - 13/18: Use continue to reduce indentation in find_dup_cset_node_entry()
>     and find_dup_cset_prop()
>
> Changes since v1:
>
>   - move patch 16/16 to 17/18
>   - move patch 15/16 to 18/18
>   - new patch 15/18
>   - new patch 16/18
>
>   - 05/18: add_changeset_node() header comment: incorrect comment for @target
>
>   - 18/18: add same fix for of_parse_phandle_with_args()
>   - 18/18: add same fix for of_parse_phandle_with_args_map()
>
>
> *** BLURB HERE ***
>
> Frank Rowand (18):
>   of: overlay: add tests to validate kfrees from overlay removal
>   of: overlay: add missing of_node_put() after add new node to changeset
>   of: overlay: add missing of_node_get() in __of_attach_node_sysfs
>   powerpc/pseries: add of_node_put() in dlpar_detach_node()
>   of: overlay: use prop add changeset entry for property in new nodes
>   of: overlay: do not duplicate properties from overlay for new nodes
>   of: dynamic: change type of of_{at,de}tach_node() to void
>   of: overlay: reorder fields in struct fragment
>   of: overlay: validate overlay properties #address-cells and
>     #size-cells
>   of: overlay: make all pr_debug() and pr_err() messages unique
>   of: overlay: test case of two fragments adding same node
>   of: overlay: check prevents multiple fragments add or delete same node
>   of: overlay: check prevents multiple fragments touching same property
>   of: unittest: remove unused of_unittest_apply_overlay() argument
>   of: overlay: set node fields from properties when add new overlay node
>   of: unittest: allow base devicetree to have symbol metadata
>   of: unittest: find overlays[] entry by name instead of index
>   of: unittest: initialize args before calling of_*parse_*()
>
>  arch/powerpc/platforms/pseries/dlpar.c             |  15 +-
>  arch/powerpc/platforms/pseries/reconfig.c          |   6 +-
>  drivers/of/dynamic.c                               |  68 +++--
>  drivers/of/kobj.c                                  |   4 +-
>  drivers/of/overlay.c                               | 292 ++++++++++++++++-----
>  drivers/of/unittest-data/Makefile                  |   2 +
>  .../of/unittest-data/overlay_bad_add_dup_node.dts  |  28 ++
>  .../of/unittest-data/overlay_bad_add_dup_prop.dts  |  24 ++
>  drivers/of/unittest-data/overlay_base.dts          |   1 +
>  drivers/of/unittest.c                              |  96 +++++--
>  include/linux/of.h                                 |  25 +-
>  11 files changed, 439 insertions(+), 122 deletions(-)
>  create mode 100644 drivers/of/unittest-data/overlay_bad_add_dup_node.dts
>  create mode 100644 drivers/of/unittest-data/overlay_bad_add_dup_prop.dts
>
> --
> Frank Rowand <frank.rowand@sony.com>
>
Rob Herring Oct. 24, 2018, 7:57 p.m. UTC | #3
On Mon, Oct 22, 2018 at 4:25 PM Alan Tull <atull@kernel.org> wrote:
>
> On Thu, Oct 18, 2018 at 5:48 PM <frowand.list@gmail.com> wrote:
> >
> > From: Frank Rowand <frank.rowand@sony.com>
> >
> > Add checks to (1) overlay apply process and (2) memory freeing
> > triggered by overlay release.  The checks are intended to detect
> > possible memory leaks and invalid overlays.
>
> I've tested v5, nothing new to report.

Does that mean everything broken or everything works great? In the
latter case, care to give a Tested-by.

Rob
Alan Tull Oct. 25, 2018, 3:25 p.m. UTC | #4
On Wed, Oct 24, 2018 at 2:57 PM Rob Herring <robh+dt@kernel.org> wrote:
>
> On Mon, Oct 22, 2018 at 4:25 PM Alan Tull <atull@kernel.org> wrote:
> >
> > On Thu, Oct 18, 2018 at 5:48 PM <frowand.list@gmail.com> wrote:
> > >
> > > From: Frank Rowand <frank.rowand@sony.com>
> > >
> > > Add checks to (1) overlay apply process and (2) memory freeing
> > > triggered by overlay release.  The checks are intended to detect
> > > possible memory leaks and invalid overlays.
> >
> > I've tested v5, nothing new to report.
>
> Does that mean everything broken or everything works great? In the
> latter case, care to give a Tested-by.
>
> Rob

Tested-by: Alan Tull <atull@kernel.org>

Alan