From b48bd16eb9fc57a463a337ca148516cdf3212d61 Mon Sep 17 00:00:00 2001 From: Gabriele Monaco Date: Wed, 10 Jun 2026 11:04:29 +0200 Subject: [PATCH] rqspinlock: Fix order in raw_res_spin_(un)lock_irq to allow schedule raw_res_spin_unlock_irqrestore() calls raw_res_spin_unlock() and then restores interrupts, this means preemption is enabled when interrupts are still disabled (as part of raw_res_spin_unlock()) so this cannot trigger an actual preemption. This is inconsistent with other spinlock implementations (raw_spin_unlock_irqrestore() and bpf_res_spin_unlock_irqrestore() itself). Adjust the macro to ensure interrupts are enabled before enabling preemption, allowing to schedule at that point. Make the same modification in the error path of raw_res_spin_lock_irqsave(). Fixes: 101acd2e78b1 ("rqspinlock: Add macros for rqspinlock usage") Cc: stable@vger.kernel.org Acked-by: Arnd Bergmann # asm-generic Acked-by: Waiman Long Acked-by: Kumar Kartikeya Dwivedi Signed-off-by: Gabriele Monaco Link: https://lore.kernel.org/r/20260610090431.32427-1-gmonaco@redhat.com Signed-off-by: Alexei Starovoitov --- include/asm-generic/rqspinlock.h | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/include/asm-generic/rqspinlock.h b/include/asm-generic/rqspinlock.h index 151d267a496b..4d46643f46cb 100644 --- a/include/asm-generic/rqspinlock.h +++ b/include/asm-generic/rqspinlock.h @@ -243,12 +243,20 @@ static __always_inline void res_spin_unlock(rqspinlock_t *lock) ({ \ int __ret; \ local_irq_save(flags); \ - __ret = raw_res_spin_lock(lock); \ - if (__ret) \ + preempt_disable(); \ + __ret = res_spin_lock(lock); \ + if (__ret) { \ local_irq_restore(flags); \ + preempt_enable(); \ + } \ __ret; \ }) -#define raw_res_spin_unlock_irqrestore(lock, flags) ({ raw_res_spin_unlock(lock); local_irq_restore(flags); }) +#define raw_res_spin_unlock_irqrestore(lock, flags) \ + ({ \ + res_spin_unlock(lock); \ + local_irq_restore(flags); \ + preempt_enable(); \ + }) #endif /* __ASM_GENERIC_RQSPINLOCK_H */