From 0414eab7c78f3518143d383e448d44fc573ac6d2 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 6 Jun 2022 14:02:38 +0900 Subject: [PATCH] clocksource: hyper-v: unexport __init-annotated hv_init_clocksource() [ Upstream commit 245b993d8f6c4e25f19191edfbd8080b645e12b1 ] EXPORT_SYMBOL and __init is a bad combination because the .init.text section is freed up after the initialization. Hence, modules cannot use symbols annotated __init. The access to a freed symbol may end up with kernel panic. modpost used to detect it, but it has been broken for a decade. Recently, I fixed modpost so it started to warn it again, then this showed up in linux-next builds. There are two ways to fix it: - Remove __init - Remove EXPORT_SYMBOL I chose the latter for this case because the only in-tree call-site, arch/x86/kernel/cpu/mshyperv.c is never compiled as modular. (CONFIG_HYPERVISOR_GUEST is boolean) Fixes: dd2cb348613b ("clocksource/drivers: Continue making Hyper-V clocksource ISA agnostic") Reported-by: Stephen Rothwell Signed-off-by: Masahiro Yamada Reviewed-by: Vitaly Kuznetsov Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20220606050238.4162200-1-masahiroy@kernel.org Signed-off-by: Wei Liu Signed-off-by: Sasha Levin --- drivers/clocksource/hyperv_timer.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index ff188ab..bb47610 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -565,4 +565,3 @@ void __init hv_init_clocksource(void) hv_sched_clock_offset = hv_read_reference_counter(); hv_setup_sched_clock(read_hv_sched_clock_msr); } -EXPORT_SYMBOL_GPL(hv_init_clocksource); -- 2.7.4