clk: bcm2835: Remove casting to bcm2835_clk_register
authorNathan Chancellor <natechancellor@gmail.com>
Sat, 16 May 2020 08:08:07 +0000 (01:08 -0700)
committerStephen Boyd <sboyd@kernel.org>
Tue, 26 May 2020 23:33:38 +0000 (16:33 -0700)
commit99a1ae29360980e79fa2d616819a6fe7411e4eda
tree397886065ec480f387ca64f634f9f43f2babbaa5
parentf376c43bec4f8ee8d1ba5c5c4cfbd6e84fb279cb
clk: bcm2835: Remove casting to bcm2835_clk_register

There are four different callback functions that are used for the
clk_register callback that all have different second parameter types.

bcm2835_register_pll -> struct bcm2835_pll_data
bcm2835_register_pll_divider -> struct bcm2835_pll_divider_data
bcm2835_register_clock -> struct bcm2835_clock_data
bcm2835_register_date -> struct bcm2835_gate_data

These callbacks are cast to bcm2835_clk_register so that there is no
error about incompatible pointer types. Unfortunately, this is a control
flow integrity violation, which verifies that the callback function's
types match the prototypes exactly before jumping.

[    0.857913] CFI failure (target: 0xffffff9334a81820):
[    0.857977] WARNING: CPU: 3 PID: 35 at kernel/cfi.c:29 __cfi_check_fail+0x50/0x58
[    0.857985] Modules linked in:
[    0.858007] CPU: 3 PID: 35 Comm: kworker/3:1 Not tainted 4.19.123-v8-01301-gdbb48f16956e4-dirty #1
[    0.858015] Hardware name: Raspberry Pi 3 Model B Rev 1.2 (DT)
[    0.858031] Workqueue: events 0xffffff9334a925c8
[    0.858046] pstate: 60000005 (nZCv daif -PAN -UAO)
[    0.858058] pc : __cfi_check_fail+0x50/0x58
[    0.858070] lr : __cfi_check_fail+0x50/0x58
[    0.858078] sp : ffffff800814ba90
[    0.858086] x29: ffffff800814ba90 x28: 000fffffffdfff3d
[    0.858101] x27: 00000000002000c2 x26: ffffff93355fdb18
[    0.858116] x25: 0000000000000000 x24: ffffff9334a81820
[    0.858131] x23: ffffff93357f3580 x22: ffffff9334af1000
[    0.858146] x21: a79b57e88f8ebc81 x20: ffffff93357f3580
[    0.858161] x19: ffffff9334a81820 x18: fffffff679769070
[    0.858175] x17: 0000000000000000 x16: 0000000000000000
[    0.858190] x15: 0000000000000004 x14: 000000000000003c
[    0.858205] x13: 0000000000003044 x12: 0000000000000000
[    0.858220] x11: b57e91cd641bae00 x10: b57e91cd641bae00
[    0.858235] x9 : b57e91cd641bae00 x8 : b57e91cd641bae00
[    0.858250] x7 : 0000000000000000 x6 : ffffff933591d4e5
[    0.858264] x5 : 0000000000000000 x4 : 0000000000000000
[    0.858279] x3 : ffffff800814b718 x2 : ffffff9334a84818
[    0.858293] x1 : ffffff9334bba66c x0 : 0000000000000029
[    0.858308] Call trace:
[    0.858321]  __cfi_check_fail+0x50/0x58
[    0.858337]  __cfi_check+0x3ab3c/0x4467c
[    0.858351]  bcm2835_clk_probe+0x210/0x2dc
[    0.858369]  platform_drv_probe+0xb0/0xfc
[    0.858380]  really_probe+0x4a0/0x5a8
[    0.858391]  driver_probe_device+0x68/0x104
[    0.858403]  __device_attach_driver+0x100/0x148
[    0.858418]  bus_for_each_drv+0xb0/0x12c
[    0.858431]  __device_attach.llvm.17225159516306086099+0xc0/0x168
[    0.858443]  bus_probe_device+0x44/0xfc
[    0.858455]  deferred_probe_work_func+0xa0/0xe0
[    0.858472]  process_one_work+0x210/0x538
[    0.858485]  worker_thread+0x2e8/0x478
[    0.858500]  kthread+0x154/0x164
[    0.858515]  ret_from_fork+0x10/0x18

To fix this, change the second parameter of all functions void * and use
a local variable with the correct type so that everything works
properly. With this, the only use of bcm2835_clk_register is in struct
bcm2835_clk_desc so we can just remove it and use the type directly.

Fixes: 56eb3a2ed972 ("clk: bcm2835: remove use of BCM2835_CLOCK_COUNT in driver")
Link: https://github.com/ClangBuiltLinux/linux/issues/1028
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://lkml.kernel.org/r/20200516080806.1459784-2-natechancellor@gmail.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
drivers/clk/bcm/clk-bcm2835.c