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Message-ID: <f543e2a4-1994-bd53-b60d-206c1e3c0726@intel.com>
Date:   Fri, 26 Aug 2022 15:48:42 -0700
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Subject: Re: [PATCH] tracepoint: Allow trace events in modules with TAINT_TEST
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To:     alison.schofield@intel.com, Steven Rostedt <rostedt@goodmis.org>
Cc:     linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org,
        Ira Weiny <ira.weiny@intel.com>,
        Dan Williams <dan.j.williams@intel.com>
References: <20220826223511.170256-1-alison.schofield@intel.com>
From:   Dave Jiang <dave.jiang@intel.com>
In-Reply-To: <20220826223511.170256-1-alison.schofield@intel.com>
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On 8/26/2022 3:35 PM, alison.schofield@intel.com wrote:
> From: Alison Schofield <alison.schofield@intel.com>
>
> Commit 2852ca7fba9f ("panic: Taint kernel if tests are run")
> introduced a new taint type, TAINT_TEST, to signal that an
> in-kernel test has been run.

has been loaded?

>
> TAINT_TEST taint type defaults into a 'bad_taint' list for
> kernel tracing and blocks the creation of trace events. This
> causes a problem for CXL testing where loading the cxl_test
> module makes all CXL modules out-of-tree, blocking any trace
> events.
>
> Trace events are in development for CXL at the moment and this
> issue was found in test with v6.0-rc1.
>
> Reported-by: Ira Weiny <ira.weiny@intel.com>
> Suggested-by: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>
> ---
>   kernel/tracepoint.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
> index 64ea283f2f86..5f17378c9dc2 100644
> --- a/kernel/tracepoint.c
> +++ b/kernel/tracepoint.c
> @@ -571,7 +571,8 @@ static void for_each_tracepoint_range(
>   bool trace_module_has_bad_taint(struct module *mod)
>   {
>   	return mod->taints & ~((1 << TAINT_OOT_MODULE) | (1 << TAINT_CRAP) |
> -			       (1 << TAINT_UNSIGNED_MODULE));
> +			       (1 << TAINT_UNSIGNED_MODULE) |
> +			       (1 << TAINT_TEST));
>   }
>   
>   static BLOCKING_NOTIFIER_HEAD(tracepoint_notify_list);
>
> base-commit: 4c612826bec1441214816827979b62f84a097e91