Re: [PATCH v5 08/18] tracing/remotes: selftests: Prefix hypervisor folder

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The dmesg forwarder will stall indefinitely if pr_info() returns 0.
--

--- Patch [8]: [PATCH v5 08/18] tracing/remotes: selftests: Prefix hypervisor folder ---
commit 72aa88bcfffb90718532218e7344002c71fad7d0
Author: Vincent Donnefort <vdonnefort@google.com>

tracing/remotes: selftests: Prefix hypervisor folder
    
Rename the hypervisor tests directory to "00hypervisor" to ensure they
run first. This prevents the hypervisor tests from being interleaved
with other remote tests which is confusing.

> diff --git a/kernel/trace/trace_remote.c b/kernel/trace/trace_remote.c
> index e6724f947170d..3a5e0d84c1722 100644
> --- a/kernel/trace/trace_remote.c
> +++ b/kernel/trace/trace_remote.c
[ ... ]
> @@ -795,26 +908,105 @@ static const struct file_operations trace_fops = {
>  	.release	= trace_release,
>  };
>  
> +static bool trace_remote_do_dmesg(struct trace_remote *remote)
> +{
> +	struct trace_remote_iterator *iter = smp_load_acquire(&remote->dmesg);
> +	unsigned int max_events = 1000;
> +
> +	if (!iter)
> +		return false;
> +
> +	trace_remote_iter_read_start(iter);
> +
> +	while (trace_remote_iter_read_event(iter)) {
> +		trace_seq_init(&iter->seq);
> +
> +		trace_remote_iter_print_event(iter);
> +		trace_seq_putc(&iter->seq, 0);
> +		if (!pr_info("%s", seq_buf_str(&iter->seq.seq)))
> +			break;
> +
> +		trace_remote_iter_move(iter);

[Severity: Medium]
Will this loop stall indefinitely if CONFIG_PRINTK is disabled?

When CONFIG_PRINTK is disabled, the pr_info() macro expands to an inline
function that unconditionally returns 0.

If that happens, the loop will break before calling trace_remote_iter_move().

Because the iterator is never advanced, the next time the polling work runs,
won't it read the exact same event and break again, creating an infinite polling
loop without making any progress?

> +
> +		if (!(--max_events))
> +			break;
> +	}
> +
> +	trace_remote_iter_read_finished(iter);
> +
> +	return !max_events;
> +}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260812161340.2417322-1-vdonnefort@google.com?part=8