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[0/2] clk: Do not register provider with a NULL dev->of_node

Message ID 20210423171335.262316-1-tudor.ambarus@microchip.com
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Series clk: Do not register provider with a NULL dev->of_node | expand

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Tudor Ambarus April 23, 2021, 5:13 p.m. UTC 
This fixes a NULL pointer dereference that was revealed by
commit 6579c8d97ad7 ("clk: Mark fwnodes when their clock provider is added")

I chose to just return -ENODEV when a driver calls devm_of_clk_add_hw_provider()
with a NULL dev->of_node, because it seems natural to return a failure when one
asks for an _of_ function to do something, but by providing with a NULL of_node.
Plus, it avoids some waste of memory, as the call to devres_alloc() will not
take place.

The opinions on how to handle this NULL pointer dereference were split, either
by returning an error when one calls devm_of_clk_add_hw_provider() with a NULL
dev->of_node, as I did, or by 
return 0 in of_clk_add_hw_provider() when np == NULL and
return 0 in of_clk_del_provider() when np == NULL.
Let me know if you prefer the second approach.

Compile tested only.

Tudor Ambarus (2):
  clk: Do not register provider with a NULL dev->of_node
  clk: bcm: rpi: Do not call devm_of_clk_add_hw_provider with a NULL
    dev->of_node

 drivers/clk/bcm/clk-raspberrypi.c | 10 ++++++----
 drivers/clk/clk.c                 | 12 +++++++-----
 2 files changed, 13 insertions(+), 9 deletions(-)