From: Greg Kroah-Hartman gregkh@linuxfoundation.org
From: Arnd Bergmann arnd@arndb.de
[ Upstream commit cbf78d85079cee662c45749ef4f744d41be85d48 ]
With clang-13, some functions only get partially inlined, with a specialized version referring to a global variable. This triggers a harmless build-time check for the intel-rng driver:
WARNING: modpost: drivers/char/hw_random/intel-rng.o(.text+0xe): Section mismatch in reference from the function stop_machine() to the function .init.text:intel_rng_hw_init() The function stop_machine() references the function __init intel_rng_hw_init(). This is often because stop_machine lacks a __init annotation or the annotation of intel_rng_hw_init is wrong.
In this instance, an easy workaround is to force the stop_machine() function to be inline, along with related interfaces that did not show the same behavior at the moment, but theoretically could.
The combination of the two patches listed below triggers the behavior in clang-13, but individually these commits are correct.
Link: https://lkml.kernel.org/r/20210225130153.1956990-1-arnd@kernel.org Fixes: fe5595c07400 ("stop_machine: Provide stop_machine_cpuslocked()") Fixes: ee527cd3a20c ("Use stop_machine_run in the Intel RNG driver") Signed-off-by: Arnd Bergmann arnd@arndb.de Cc: Nathan Chancellor nathan@kernel.org Cc: Nick Desaulniers ndesaulniers@google.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Sebastian Andrzej Siewior bigeasy@linutronix.de Cc: "Paul E. McKenney" paulmck@kernel.org Cc: Ingo Molnar mingo@kernel.org Cc: Prarit Bhargava prarit@redhat.com Cc: Daniel Bristot de Oliveira bristot@redhat.com Cc: Peter Zijlstra peterz@infradead.org Cc: Valentin Schneider valentin.schneider@arm.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/stop_machine.h | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h index 30577c3aecf8..46fb3ebdd16e 100644 --- a/include/linux/stop_machine.h +++ b/include/linux/stop_machine.h @@ -128,7 +128,7 @@ int stop_machine_from_inactive_cpu(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus); #else /* CONFIG_SMP || CONFIG_HOTPLUG_CPU */
-static inline int stop_machine_cpuslocked(cpu_stop_fn_t fn, void *data, +static __always_inline int stop_machine_cpuslocked(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus) { unsigned long flags; @@ -139,14 +139,15 @@ static inline int stop_machine_cpuslocked(cpu_stop_fn_t fn, void *data, return ret; }
-static inline int stop_machine(cpu_stop_fn_t fn, void *data, - const struct cpumask *cpus) +static __always_inline int +stop_machine(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus) { return stop_machine_cpuslocked(fn, data, cpus); }
-static inline int stop_machine_from_inactive_cpu(cpu_stop_fn_t fn, void *data, - const struct cpumask *cpus) +static __always_inline int +stop_machine_from_inactive_cpu(cpu_stop_fn_t fn, void *data, + const struct cpumask *cpus) { return stop_machine(fn, data, cpus); }