[PATCH v7 00/12] Fix broken usage of driver_override (and kfree of static memory)

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

Hi,

This is a continuation of my old patchset from 2019. [1]
Back then, few drivers set driver_override wrong. I fixed Exynos
in a different way after discussions. QCOM NGD was not fixed
and a new user appeared - IMX SCU.

It seems "char *" in driver_override looks too consty, so we
tend to make a mistake of storing there string literals.

Changes since latest v7
=======================
1. Patch #1: remove out_free label, document clearing override in kerneldoc and
   in code-comments (Andy).
2. Patch #12 (rpmsg): do not duplicate string (Biju).

Changes since latest v6
=======================
1. Patch #1: Don't check for !dev and handle len==0 (Andy).
2. New patch #11 (rpmsg): split constifying of local variable to a new patch.

Changes since latest v5
=======================
1. Patch #11 (rpmsg): split from previous patch 11 - easier to understand the
   need of it.
2. Fix build issue in patch 12 (rpmsg).

Changes since latest v4
=======================
1. Correct commit msgs and comments after Andy's review.
2. Re-order code in new helper (patch #1) (Andy).
3. Add tags.

Changes since latest v3
=======================
1. Wrap comments, extend comment in driver_set_override() about newline.
2. Minor commit msg fixes.
3. Add tags.

Changes since latest v2
=======================
1. Make all driver_override fields as "const char *", just like SPI
   and VDPA. (Mark)
2. Move "count" check to the new helper and add "count" argument. (Michael)
3. Fix typos in docs, patch subject. Extend doc. (Michael, Bjorn)
4. Compare pointers to reduce number of string readings in the helper.
5. Fix clk-imx return value.

Changes since latest v1 (not the old 2019 solution):
====================================================
https://lore.kernel.org/all/708eabb1-7b35-d525-d4c3-451d4a3de84f@rasmusvillemoes.dk/
1. Add helper for setting driver_override.
2. Use the helper.

Dependencies (and stable):
==========================
1. All patches, including last three fixes, depend on the first patch
   introducing the helper.
2. The last three commits - fixes - are probably not backportable
   directly, because of this dependency. I don't know how to express
   this dependency here, since stable-kernel-rules.rst mentions only commits as
   possible dependencies.

[1] https://lore.kernel.org/all/1550484960-2392-3-git-send-email-krzk@kernel.org/

Best regards,
Krzysztof

Krzysztof Kozlowski (12):
  driver: platform: Add helper for safer setting of driver_override
  amba: Use driver_set_override() instead of open-coding
  fsl-mc: Use driver_set_override() instead of open-coding
  hv: Use driver_set_override() instead of open-coding
  PCI: Use driver_set_override() instead of open-coding
  s390/cio: Use driver_set_override() instead of open-coding
  spi: Use helper for safer setting of driver_override
  vdpa: Use helper for safer setting of driver_override
  clk: imx: scu: Fix kfree() of static memory on setting driver_override
  slimbus: qcom-ngd: Fix kfree() of static memory on setting
    driver_override
  rpmsg: Constify local variable in field store macro
  rpmsg: Fix kfree() of static memory on setting driver_override

 drivers/amba/bus.c              | 28 ++-----------
 drivers/base/driver.c           | 69 +++++++++++++++++++++++++++++++++
 drivers/base/platform.c         | 28 ++-----------
 drivers/bus/fsl-mc/fsl-mc-bus.c | 25 ++----------
 drivers/clk/imx/clk-scu.c       |  7 +++-
 drivers/hv/vmbus_drv.c          | 28 ++-----------
 drivers/pci/pci-sysfs.c         | 28 ++-----------
 drivers/rpmsg/rpmsg_core.c      |  3 +-
 drivers/rpmsg/rpmsg_internal.h  | 13 ++++++-
 drivers/rpmsg/rpmsg_ns.c        | 14 ++++++-
 drivers/s390/cio/cio.h          |  6 ++-
 drivers/s390/cio/css.c          | 28 ++-----------
 drivers/slimbus/qcom-ngd-ctrl.c | 13 ++++++-
 drivers/spi/spi.c               | 26 ++-----------
 drivers/vdpa/vdpa.c             | 29 ++------------
 include/linux/amba/bus.h        |  6 ++-
 include/linux/device/driver.h   |  2 +
 include/linux/fsl/mc.h          |  6 ++-
 include/linux/hyperv.h          |  6 ++-
 include/linux/pci.h             |  6 ++-
 include/linux/platform_device.h |  6 ++-
 include/linux/rpmsg.h           |  6 ++-
 include/linux/spi/spi.h         |  2 +
 include/linux/vdpa.h            |  4 +-
 24 files changed, 184 insertions(+), 205 deletions(-)

-- 
2.32.0