From: Srikar Dronamraju srikar@linux.vnet.ibm.com
commit 333cf507465fbebb3727f5b53e77538467df312a upstream.
With commit c9f3401313a5 ("powerpc: Always enable queued spinlocks for 64s, disable for others") CONFIG_PPC_QUEUED_SPINLOCKS is always enabled on ppc64le, external modules that use spinlock APIs are failing.
ERROR: modpost: GPL-incompatible module XXX.ko uses GPL-only symbol 'shared_processor'
Before the above commit, modules were able to build without any issues. Also this problem is not seen on other architectures. This problem can be workaround if CONFIG_UNINLINE_SPIN_UNLOCK is enabled in the config. However CONFIG_UNINLINE_SPIN_UNLOCK is not enabled by default and only enabled in certain conditions like CONFIG_DEBUG_SPINLOCKS is set in the kernel config.
#include <linux/module.h> spinlock_t spLock;
static int __init spinlock_test_init(void) { spin_lock_init(&spLock); spin_lock(&spLock); spin_unlock(&spLock); return 0; }
static void __exit spinlock_test_exit(void) { printk("spinlock_test unloaded\n"); } module_init(spinlock_test_init); module_exit(spinlock_test_exit);
MODULE_DESCRIPTION ("spinlock_test"); MODULE_LICENSE ("non-GPL"); MODULE_AUTHOR ("Srikar Dronamraju");
Given that spin locks are one of the basic facilities for module code, this effectively makes it impossible to build/load almost any non GPL modules on ppc64le.
This was first reported at https://github.com/openzfs/zfs/issues/11172
Currently shared_processor is exported as GPL only symbol. Fix this for parity with other architectures by exposing shared_processor to non-GPL modules too.
Fixes: 14c73bd344da ("powerpc/vcpu: Assume dedicated processors as non-preempt") Cc: stable@vger.kernel.org # v5.5+ Reported-by: marc.c.dionne@gmail.com Signed-off-by: Srikar Dronamraju srikar@linux.vnet.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20210729060449.292780-1-srikar@linux.vnet.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/powerpc/platforms/pseries/setup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -76,7 +76,7 @@ #include "../../../../drivers/pci/pci.h"
DEFINE_STATIC_KEY_FALSE(shared_processor); -EXPORT_SYMBOL_GPL(shared_processor); +EXPORT_SYMBOL(shared_processor);
int CMO_PrPSP = -1; int CMO_SecPSP = -1;