Messages in this thread Patch in this message | | | From | Marc Zyngier <> | Subject | [PATCH] clocksource/drivers/arm_arch_timer: Force inlining of erratum_set_next_event_generic() | Date | Wed, 17 Nov 2021 11:35:32 +0000 |
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With some specific kernel configuration and Clang, the kernel fails to like with something like:
ld.lld: error: undefined symbol: __compiletime_assert_200 >>> referenced by arch_timer.h:156 (./arch/arm64/include/asm/arch_timer.h:156) >>> clocksource/arm_arch_timer.o:(erratum_set_next_event_generic) in archive drivers/built-in.a
ld.lld: error: undefined symbol: __compiletime_assert_197 >>> referenced by arch_timer.h:133 (./arch/arm64/include/asm/arch_timer.h:133) >>> clocksource/arm_arch_timer.o:(erratum_set_next_event_generic) in archive drivers/built-in.a make: *** [Makefile:1161: vmlinux] Error 1
These are due to the BUILD_BUG() macros contained in the low-level accessors (arch_timer_reg_{write,read}_cp15) being emitted, as the access type wasn't known at compile time.
Fix this by making erratum_set_next_event_generic() __force_inline, resulting in the 'access' parameter to be resolved at compile time, similarly to what is already done for set_next_event().
Fixes: 4775bc63f880 ("Add build-time guards for unhandled register accesses") Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Nick Desaulniers <ndesaulniers@google.com> --- drivers/clocksource/arm_arch_timer.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 9a04eacc4412..1ecd52f903b8 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -394,8 +394,13 @@ EXPORT_SYMBOL_GPL(timer_unstable_counter_workaround); static atomic_t timer_unstable_counter_workaround_in_use = ATOMIC_INIT(0); -static void erratum_set_next_event_generic(const int access, unsigned long evt, - struct clock_event_device *clk) +/* + * Force the inlining of this function so that the register accesses + * can be themselves correctly inlined. + */ +static __always_inline +void erratum_set_next_event_generic(const int access, unsigned long evt, + struct clock_event_device *clk) { unsigned long ctrl; u64 cval; -- 2.30.2
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