A subsequent patch calls cpuset_cpus_allowed() in the vfio driver pci
code. Export the symbol to be able to build the vfio driver as a kernel
module.

This is not enough, however: when CONFIG_CPUSETS is _not_ defined
cpuset_cpus_allowed() is an inline function returning
task_cpu_possible_mask(). For the arm64 architecture this function is
also inline: it checks the arm64_mismatched_32bit_el0 static key and
calls system_32bit_el0_cpumask(). We need to export those symbols as
well.

Signed-off-by: Fred Griffoul <fgriffo@amazon.co.uk>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406060731.L3NSR1Hy-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202406070659.pYu6zNrx-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202406101154.iaDyTRwZ-lkp@intel.com/
---
 arch/arm64/kernel/cpufeature.c | 2 ++
 kernel/cgroup/cpuset.c         | 1 +
 2 files changed, 3 insertions(+)

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 56583677c1f2..2f1de6343bee 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -127,6 +127,7 @@ static bool __read_mostly allow_mismatched_32bit_el0;
  * seen at least one CPU capable of 32-bit EL0.
  */
 DEFINE_STATIC_KEY_FALSE(arm64_mismatched_32bit_el0);
+EXPORT_SYMBOL_GPL(arm64_mismatched_32bit_el0);
 
 /*
  * Mask of CPUs supporting 32-bit EL0.
@@ -1614,6 +1615,7 @@ const struct cpumask *system_32bit_el0_cpumask(void)
 
 	return cpu_possible_mask;
 }
+EXPORT_SYMBOL_GPL(system_32bit_el0_cpumask);
 
 static int __init parse_32bit_el0_param(char *str)
 {
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 4237c8748715..9fd56222aa4b 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -4764,6 +4764,7 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
 	rcu_read_unlock();
 	spin_unlock_irqrestore(&callback_lock, flags);
 }
+EXPORT_SYMBOL_GPL(cpuset_cpus_allowed);
 
 /**
  * cpuset_cpus_allowed_fallback - final fallback before complete catastrophe.
-- 
2.40.1

On Tue, Jun 11, 2024 at 05:44:24PM +0000, Fred Griffoul wrote:
> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
> index 56583677c1f2..2f1de6343bee 100644
> --- a/arch/arm64/kernel/cpufeature.c
> +++ b/arch/arm64/kernel/cpufeature.c
> @@ -127,6 +127,7 @@ static bool __read_mostly allow_mismatched_32bit_el0;
>   * seen at least one CPU capable of 32-bit EL0.
>   */
>  DEFINE_STATIC_KEY_FALSE(arm64_mismatched_32bit_el0);
> +EXPORT_SYMBOL_GPL(arm64_mismatched_32bit_el0);
>  
>  /*
>   * Mask of CPUs supporting 32-bit EL0.
> @@ -1614,6 +1615,7 @@ const struct cpumask *system_32bit_el0_cpumask(void)
>  
>  	return cpu_possible_mask;
>  }
> +EXPORT_SYMBOL_GPL(system_32bit_el0_cpumask);

For the arm64 bits:

Acked-by: Catalin Marinas <catalin.marinas@arm.com>

On 6/11/24 13:44, Fred Griffoul wrote:
> A subsequent patch calls cpuset_cpus_allowed() in the vfio driver pci
> code. Export the symbol to be able to build the vfio driver as a kernel
> module.
>
> This is not enough, however: when CONFIG_CPUSETS is _not_ defined
> cpuset_cpus_allowed() is an inline function returning
> task_cpu_possible_mask(). For the arm64 architecture this function is
> also inline: it checks the arm64_mismatched_32bit_el0 static key and
> calls system_32bit_el0_cpumask(). We need to export those symbols as
> well.
>
> Signed-off-by: Fred Griffoul <fgriffo@amazon.co.uk>
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202406060731.L3NSR1Hy-lkp@intel.com/
> Closes: https://lore.kernel.org/oe-kbuild-all/202406070659.pYu6zNrx-lkp@intel.com/
> Closes: https://lore.kernel.org/oe-kbuild-all/202406101154.iaDyTRwZ-lkp@intel.com/
> ---
>   arch/arm64/kernel/cpufeature.c | 2 ++
>   kernel/cgroup/cpuset.c         | 1 +
>   2 files changed, 3 insertions(+)
>
> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
> index 56583677c1f2..2f1de6343bee 100644
> --- a/arch/arm64/kernel/cpufeature.c
> +++ b/arch/arm64/kernel/cpufeature.c
> @@ -127,6 +127,7 @@ static bool __read_mostly allow_mismatched_32bit_el0;
>    * seen at least one CPU capable of 32-bit EL0.
>    */
>   DEFINE_STATIC_KEY_FALSE(arm64_mismatched_32bit_el0);
> +EXPORT_SYMBOL_GPL(arm64_mismatched_32bit_el0);
>   
>   /*
>    * Mask of CPUs supporting 32-bit EL0.
> @@ -1614,6 +1615,7 @@ const struct cpumask *system_32bit_el0_cpumask(void)
>   
>   	return cpu_possible_mask;
>   }
> +EXPORT_SYMBOL_GPL(system_32bit_el0_cpumask);
>   
>   static int __init parse_32bit_el0_param(char *str)
>   {
> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
> index 4237c8748715..9fd56222aa4b 100644
> --- a/kernel/cgroup/cpuset.c
> +++ b/kernel/cgroup/cpuset.c
> @@ -4764,6 +4764,7 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
>   	rcu_read_unlock();
>   	spin_unlock_irqrestore(&callback_lock, flags);
>   }
> +EXPORT_SYMBOL_GPL(cpuset_cpus_allowed);
>   
>   /**
>    * cpuset_cpus_allowed_fallback - final fallback before complete catastrophe.
Acked-by: Waiman Long <longman@redhat.com>