[PATCH v4] x86/rtc: Remove __init for runtime functions

From: Matija Glavinic Pecotic
Date: Thu Nov 24 2022 - 13:39:05 EST


set_rtc_noop, get_rtc_noop are used runtime, therefore need init removed.
Crash was observed on x86 platform where cmos rtc is unused and disabled
via device tree. Function was triggered from ntp: sync_hw_clock, although
CONFIG_RTC_SYSTOHC=n, however sync_cmos_clock doesn't honour that.

Workqueue: events_power_efficient sync_hw_clock
RIP: 0010:set_rtc_noop
Call Trace:
update_persistent_clock64
sync_hw_clock

Fix by dropping __init and making set/get_rtc_noop available runtime.

Fixes: c311ed6183f4 ("x86/init: Allow DT configured systems to disable RTC at boot time")
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Signed-off-by: Matija Glavinic Pecotic <matija.glavinic-pecotic.ext@xxxxxxxxx>
---
v4: Update commit subject and message based on Andy's comments, resend to proper addresses
v3: Update commit message based on Andy's comments (further trim to backtrace, proper tag)
v2: Update commit message based on Andy's comments

arch/x86/kernel/x86_init.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
index 57353519bc11..0ab707bbefe2 100644
--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -32,8 +32,8 @@ static int __init iommu_init_noop(void) { return 0; }
static void iommu_shutdown_noop(void) { }
bool __init bool_x86_init_noop(void) { return false; }
void x86_op_int_noop(int cpu) { }
-static __init int set_rtc_noop(const struct timespec64 *now) { return -EINVAL; }
-static __init void get_rtc_noop(struct timespec64 *now) { }
+static int set_rtc_noop(const struct timespec64 *now) { return -EINVAL; }
+static void get_rtc_noop(struct timespec64 *now) { }

static __initconst const struct of_device_id of_cmos_match[] = {
{ .compatible = "motorola,mc146818" },
--
2.31.0