From 3f1fe48a36b0b6722dc3fd421d93512bac138e9a Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 2 Oct 2026 12:17:24 -0700 Subject: Merge tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux Pull io_uring fixes from Jens Axboe: - Fix a task_work add use-after-free with SQPOLL. The sqpoll thread could pop and complete the last request while io_req_normal_work_add() was still looking at them after the mpscq push. Use the same approach as DEFER_TASKRUN to protect from that, holding an RCU read lock across the add, and have exit wait for an RCU grace period for SQPOLL rings as well. - CQE32 ring fixes: correct the free entry check for 32b CQEs, zero the big_cqe for aux CQEs, and only post the dummy skip CQE on CQE_MIXED rings - Mark the source filter table as COW when cloning bpf filters, so registering another filter on the source doesn't modify the shared table in place - Initialize the task context before running the BPF loop - Requeue zcrx multishot receives stopped by a local resource - End a TX_TIMESTAMP multishot cmd when the CQ is full (lollipopkit) * tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: io_uring: fix task_work add use-after-free with SQPOLL io_uring/cmd_net: end TX_TIMESTAMP multishot when the CQ is full io_uring/zcrx: requeue multishot receives stopped by a local resource io_uring: initialize task context before running the BPF loop io_uring: zero big_cqe for aux CQEs on CQE32 rings io_uring: fix free entry check for 32b CQEs on CQE32 rings io_uring: only post the dummy skip CQE on CQE_MIXED rings io_uring/bpf_filter: mark source as COW when cloning filters --- include/asm-generic/preempt.h | 114 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) create mode 100644 include/asm-generic/preempt.h (limited to 'include/asm-generic/preempt.h') diff --git a/include/asm-generic/preempt.h b/include/asm-generic/preempt.h new file mode 100644 index 000000000..c8683c046 --- /dev/null +++ b/include/asm-generic/preempt.h @@ -0,0 +1,114 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_PREEMPT_H +#define __ASM_PREEMPT_H + +#include + +#define PREEMPT_ENABLED (0) + +static __always_inline int preempt_count(void) +{ + return READ_ONCE(current_thread_info()->preempt_count); +} + +static __always_inline volatile int *preempt_count_ptr(void) +{ + return ¤t_thread_info()->preempt_count; +} + +static __always_inline void preempt_count_set(int pc) +{ + *preempt_count_ptr() = pc; +} + +/* + * must be macros to avoid header recursion hell + */ +#define init_task_preempt_count(p) do { \ + task_thread_info(p)->preempt_count = FORK_PREEMPT_COUNT; \ +} while (0) + +#define init_idle_preempt_count(p, cpu) do { \ + task_thread_info(p)->preempt_count = PREEMPT_DISABLED; \ +} while (0) + +static __always_inline void set_preempt_need_resched(void) +{ +} + +static __always_inline void clear_preempt_need_resched(void) +{ +} + +static __always_inline bool test_preempt_need_resched(void) +{ + return false; +} + +/* + * The various preempt_count add/sub methods + */ + +static __always_inline void __preempt_count_add(int val) +{ + *preempt_count_ptr() += val; +} + +static __always_inline void __preempt_count_sub(int val) +{ + *preempt_count_ptr() -= val; +} + +static __always_inline int __preempt_count_add_return(int val) +{ + *preempt_count_ptr() += val; + + return *preempt_count_ptr(); +} + +static __always_inline int __preempt_count_sub_return(int val) +{ + *preempt_count_ptr() -= val; + + return *preempt_count_ptr(); +} + +static __always_inline bool __preempt_count_dec_and_test(void) +{ + /* + * Because of load-store architectures cannot do per-cpu atomic + * operations; we cannot use PREEMPT_NEED_RESCHED because it might get + * lost. + */ + return !--*preempt_count_ptr() && tif_need_resched(); +} + +/* + * Returns true when we need to resched and can (barring IRQ state). + */ +static __always_inline bool should_resched(int preempt_offset) +{ + return unlikely(preempt_count() == preempt_offset && + tif_need_resched()); +} + +#ifdef CONFIG_PREEMPTION +extern asmlinkage void preempt_schedule(void); +extern asmlinkage void preempt_schedule_notrace(void); + +#if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) + +void dynamic_preempt_schedule(void); +void dynamic_preempt_schedule_notrace(void); +#define __preempt_schedule() dynamic_preempt_schedule() +#define __preempt_schedule_notrace() dynamic_preempt_schedule_notrace() + +#else /* !CONFIG_PREEMPT_DYNAMIC || !CONFIG_HAVE_PREEMPT_DYNAMIC_KEY*/ + +#define __preempt_schedule() preempt_schedule() +#define __preempt_schedule_notrace() preempt_schedule_notrace() + +#endif /* CONFIG_PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_KEY*/ +#endif /* CONFIG_PREEMPTION */ + +#endif /* __ASM_PREEMPT_H */ -- cgit v1.3.1