[PATCH v6 0/3] devres: provide and use devm_krealloc()

From: Bartosz Golaszewski
Date: Sun Aug 02 2020 - 04:35:36 EST

From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>

Hi Greg, Andy,

this is a reworked version of devm_krealloc(). This time without the risk
of sleeping with spinlock taken. I noticed that devres_lock is only there
to protect the integrity of the devres list - we can assume users are sane
enough to not devm_kfree() chunks that they devm_krealloc() at the same time
so we only take the lock when manipulating the list now.

I dropped Andy's review tag due to this change.


Regular krealloc() obviously can't work with managed memory. This series
implements devm_krealloc() and adds the first users with hope that this
helper will be adopted by other drivers currently using non-managed

Some additional changes to the code modified by main patches are included.

v1 -> v2:
- remove leftover call to hwmon_device_unregister() from pmbus_core.c
- add a patch extending devm_kmalloc() to handle zero size case
- use WARN_ON() instead of WARN_ONCE() in devm_krealloc() when passed
a pointer to non-managed memory
- correctly handle the case when devm_krealloc() is passed a pointer to
memory in .rodata (potentially returned by devm_kstrdup_const())
- correctly handle ZERO_SIZE_PTR passed as the ptr argument in devm_krealloc()

v2 -> v3:
- drop already applied patches
- collect Acks
- add an additional user in iio

v3 -> v4:
- add the kerneldoc for devm_krealloc()
- WARN() outside of spinlock
- rename local variable

v4 -> v5:
- tweak the kerneldoc

v5 -> v6:
- tweak the devres_lock handling in devm_krealloc()

Bartosz Golaszewski (3):
devres: provide devm_krealloc()
hwmon: pmbus: use more devres helpers
iio: adc: xilinx-xadc: use devm_krealloc()

.../driver-api/driver-model/devres.rst | 1 +
drivers/base/devres.c | 65 +++++++++++++++++++
drivers/hwmon/pmbus/pmbus_core.c | 28 +++-----
drivers/iio/adc/xilinx-xadc-core.c | 16 ++---
include/linux/device.h | 2 +
5 files changed, 85 insertions(+), 27 deletions(-)