git: 1ae20f7c70ea - main - kern: malloc: fix panic on M_WAITOK during THREAD_NO_SLEEPING()

[John Baldwin]

On 3/9/21 3:17 AM, Kyle Evans wrote:
> The branch main has been updated by kevans:
> 
> URL: https://cgit.FreeBSD.org/src/commit/?id=1ae20f7c70ea16fa8b702e409030e170df4f5c13
> 
> commit 1ae20f7c70ea16fa8b702e409030e170df4f5c13
> Author:     Kyle Evans <kevans at FreeBSD.org>
> AuthorDate: 2021-03-08 06:16:27 +0000
> Commit:     Kyle Evans <kevans at FreeBSD.org>
> CommitDate: 2021-03-09 11:16:39 +0000
> 
>      kern: malloc: fix panic on M_WAITOK during THREAD_NO_SLEEPING()
>      
>      Simple condition flip; we wanted to panic here after epoch_trace_list().
>      
>      Reviewed by:    glebius, markj
>      MFC after:      3 days
>      Differential Revision:  https://reviews.freebsd.org/D29125
> ---
>   sys/kern/kern_malloc.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/sys/kern/kern_malloc.c b/sys/kern/kern_malloc.c
> index 48383358e3ad..0d6f9dcfcab7 100644
> --- a/sys/kern/kern_malloc.c
> +++ b/sys/kern/kern_malloc.c
> @@ -537,7 +537,7 @@ malloc_dbg(caddr_t *vap, size_t *sizep, struct malloc_type *mtp,
>   #ifdef EPOCH_TRACE
>   			epoch_trace_list(curthread);
>   #endif
> -			KASSERT(1,
> +			KASSERT(0,
>   			    ("malloc(M_WAITOK) with sleeping prohibited"));

I would perhaps just use panic() directly under INVARIANTS instead of KASSERT(false, ...)

Either that or duplicate the condition and let the compiler deal with avoiding checking
it twice, e.g.:

#ifdef EPOCH_TRACE
      if (!THREAD_CAN_SLEEP())
          epoc_trace_list(curthread);
#endif
      KASSERT(THREAD_CAN_SLEEP(), ("malloc(M_WAITOK) with sleeping prohibited"));


-- 
John Baldwin