diff options
| author | Gabriele Monaco <gmonaco@redhat.com> | 2026-06-10 12:04:29 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-06-13 06:35:38 +0300 |
| commit | b48bd16eb9fc57a463a337ca148516cdf3212d61 (patch) | |
| tree | 3f1d6b6405b72623dc4d66c1cbb5218fed08e161 /include | |
| parent | 2ae53824b4462a13c2c773c57b2d2180a11d7fea (diff) | |
| download | linux-b48bd16eb9fc57a463a337ca148516cdf3212d61.tar.xz | |
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 <arnd@arndb.de> # asm-generic
Acked-by: Waiman Long <longman@redhat.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/20260610090431.32427-1-gmonaco@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-generic/rqspinlock.h | 14 |
1 files 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 */ |