Re: [GIT PULL] tracing: Fixes for v6.17

[Nathan Chancellor <nathan@kernel.org>]

On Fri, Aug 22, 2025 at 05:39:59PM -0400, Steven Rostedt wrote:
> On Fri, 22 Aug 2025 14:23:11 -0700
> Nathan Chancellor <nathan@kernel.org> wrote:
> 
> > > Actually, can you see if this fixes the bug you are seeing?  
> > 
> > Yes, it does.
> > 
> > Tested-by: Nathan Chancellor <nathan@kernel.org>
> 
> Ah, that patch isn't good, as iter->hash must be non NULL going forward,
> otherwise it thinks it failed to allocated.
> 
> Could you test this one instead?

Yes, this one works as well for that test.

> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index f992a5eb878e..a69067367c29 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -4662,7 +4662,10 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag,
>  			iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
>  		}
>  	} else {
> -		iter->hash = alloc_and_copy_ftrace_hash(hash->size_bits, hash);
> +		if (hash)
> +			iter->hash = alloc_and_copy_ftrace_hash(hash->size_bits, hash);
> +		else
> +			iter->hash = EMPTY_HASH;
>  	}
>  
>  	if (!iter->hash) {
> 
> 
> Thanks,
> 
> -- Steve