netdev - Re: [PATCH bpf-next v1 1/1] bpf: Annotate rqspinlock lock acquiring functions with __must

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAP01T74CcZqt9W8Y5T3NYheU8HyGataKXFw99cnLC46ZV9oFPQ@mail.gmail.com>
Date: Tue, 18 Nov 2025 05:16:50 -0500
From: Kumar Kartikeya Dwivedi <memxor@...il.com>
To: Amery Hung <ameryhung@...il.com>
Cc: bpf@...r.kernel.org, netdev@...r.kernel.org, alexei.starovoitov@...il.com, 
	andrii@...nel.org, daniel@...earbox.net, kernel-team@...a.com
Subject: Re: [PATCH bpf-next v1 1/1] bpf: Annotate rqspinlock lock acquiring
 functions with __must_check

On Mon, 17 Nov 2025 at 14:15, Amery Hung <ameryhung@...il.com> wrote:
>
> Locking a resilient queued spinlock can fail when deadlock or timeout
> happen. Mark the lock acquring functions with __must_check to make sure
> callers always handle the returned error.
>
> Suggested-by: Andrii Nakryiko <andrii@...nel.org>
> Signed-off-by: Amery Hung <ameryhung@...il.com>
> ---

Looks like it's working :)
I would just explicitly ignore with (void) cast the locktorture case.
After that is fixed, you can add:

Acked-by: Kumar Kartikeya Dwivedi <memxor@...il.com>

Thanks!

>  include/asm-generic/rqspinlock.h | 47 +++++++++++++++++++-------------
>  1 file changed, 28 insertions(+), 19 deletions(-)
>
> diff --git a/include/asm-generic/rqspinlock.h b/include/asm-generic/rqspinlock.h
> index 6d4244d643df..855c09435506 100644
> --- a/include/asm-generic/rqspinlock.h
> +++ b/include/asm-generic/rqspinlock.h
> @@ -171,7 +171,7 @@ static __always_inline void release_held_lock_entry(void)
>   * * -EDEADLK  - Lock acquisition failed because of AA/ABBA deadlock.
>   * * -ETIMEDOUT - Lock acquisition failed because of timeout.
>   */
> -static __always_inline int res_spin_lock(rqspinlock_t *lock)
> +static __always_inline __must_check int res_spin_lock(rqspinlock_t *lock)
>  {
>         int val = 0;
>
> @@ -223,27 +223,36 @@ static __always_inline void res_spin_unlock(rqspinlock_t *lock)
>  #define raw_res_spin_lock_init(lock) ({ *(lock) = (rqspinlock_t){0}; })
>  #endif
>
> -#define raw_res_spin_lock(lock)                    \
> -       ({                                         \
> -               int __ret;                         \
> -               preempt_disable();                 \
> -               __ret = res_spin_lock(lock);       \
> -               if (__ret)                         \
> -                       preempt_enable();          \
> -               __ret;                             \
> -       })
> +static __always_inline __must_check int raw_res_spin_lock(rqspinlock_t *lock)
> +{
> +       int ret;
> +
> +       preempt_disable();
> +       ret = res_spin_lock(lock);
> +       if (ret)
> +               preempt_enable();
> +
> +       return ret;
> +}
>
>  #define raw_res_spin_unlock(lock) ({ res_spin_unlock(lock); preempt_enable(); })
>
> -#define raw_res_spin_lock_irqsave(lock, flags)    \
> -       ({                                        \
> -               int __ret;                        \
> -               local_irq_save(flags);            \
> -               __ret = raw_res_spin_lock(lock);  \
> -               if (__ret)                        \
> -                       local_irq_restore(flags); \
> -               __ret;                            \
> -       })
> +static __always_inline __must_check int
> +__raw_res_spin_lock_irqsave(rqspinlock_t *lock, unsigned long *flags)
> +{
> +       unsigned long __flags;
> +       int ret;
> +
> +       local_irq_save(__flags);
> +       ret = raw_res_spin_lock(lock);
> +       if (ret)
> +               local_irq_restore(__flags);
> +
> +       *flags = __flags;
> +       return ret;
> +}
> +
> +#define raw_res_spin_lock_irqsave(lock, flags) __raw_res_spin_lock_irqsave(lock, &flags)
>
>  #define raw_res_spin_unlock_irqrestore(lock, flags) ({ raw_res_spin_unlock(lock); local_irq_restore(flags); })
>
> --
> 2.47.3
>