From: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
To: Joel Fernandes <joel@joelfernandes.org>,
Kees Cook <keescook@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Stephen Boyd <sboyd@kernel.org>,
Bjorn Andersson <bjorn.andersson@linaro.org>,
Andy Gross <andy.gross@linaro.org>,
David Brown <david.brown@linaro.org>,
Jiri Slaby <jslaby@suse.com>,
"Ivan T. Ivanov" <ivan.ivanov@linaro.org>,
Geliang Tang <geliangtang@gmail.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Pramod Gurav <gpramod@codeaurora.org>,
linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org,
"open list:SERIAL DRIVERS" <linux-serial@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Rajendra Nayak <rnayak@codeaurora.org>,
Vivek Gautam <vivek.gautam@codeaurora.org>,
Sibi Sankar <sibis@codeaurora.org>
Subject: Re: Crash in msm serial on dragonboard with ftrace bootargs
Date: Wed, 17 Oct 2018 17:08:09 +0530 [thread overview]
Message-ID: <2a23cd74-7364-0fb7-3c7b-7be79a881073@codeaurora.org> (raw)
In-Reply-To: <20181017101355.GA230639@joelaf.mtv.corp.google.com>
On 10/17/2018 3:43 PM, Joel Fernandes wrote:
> Hi Kees,
>
> On Tue, Oct 16, 2018 at 10:02:53AM -0700, Kees Cook wrote:
>> On Tue, Oct 16, 2018 at 8:29 AM, Steven Rostedt <rostedt@goodmis.org> wrote:
>>> On Tue, 16 Oct 2018 17:08:25 +0530
>>> Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> wrote:
>>>> One more thing is for pstore dmesg-ramoops, I had to change
>>>> late_initcall to postcore_initcall which brings the question as to why
>>>> we changed to late_initcall?
>>>> Simple git blame shows to support crypto compress api, but is it really
>>>> helpful? A lot of boottime issues can be caught with pstore enabled at
>>>> postcore_initcall rather than late_initcall, this backtrace
>>>> is just one example. Is there any way we could change this?
>>>
>>> Does it break if the crypto is not initialized? Perhaps add a command
>>> line flag to have it happen earlier:
>>>
>>> ramoops=earlyinit
>>>
>>> and add a postcore_initcall that checks if that flag is set, and if so,
>>> it does the work then, and the late_initcall() will do nothing.
>>>
>>> That way, you can still have unmodified kernels use pstore when it
>>> crashes at boot up.
>>
>> Even better, if we could find a way to make it work with a late
>> initialization of compression (i.e. postcore_initcall() by default
>> means anything caught would be uncompressed, but anything after
>> late_initcall() would be compressed). I'd be very happy to review
>> patches for that!
>
> What do you think about the (untested) patch below? It seems to me that it
> should solve the issue of missing early crash dumps, but I have not tested it
> yet. Sai, would you mind trying it out and let me know if you can see the
> early crash dumps properly now?
>
> ----8<---
> From: "Joel Fernandes (Google)" <joel@joelfernandes.org>
> Subject: [RFC] pstore: allocate compression during late_initcall
>
> ramoop's pstore registration (using pstore_register) has to run during
> late_initcall because crypto backend may not be ready during
> postcore_initcall. This causes missing of dmesg crash dumps which could
> have been caught by pstore.
>
> Instead, lets allow ramoops pstore registration earlier, and once crypto
> is ready we can initialize the compression.
>
> Reported-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
> ---
> fs/pstore/platform.c | 13 +++++++++++++
> fs/pstore/ram.c | 2 +-
> 2 files changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
> index 15e99d5a681d..f09066db2d4d 100644
> --- a/fs/pstore/platform.c
> +++ b/fs/pstore/platform.c
> @@ -780,6 +780,19 @@ void __init pstore_choose_compression(void)
> }
> }
>
> +static int __init pstore_compression_late_init(void)
> +{
> + /*
> + * Check if any pstore backends registered earlier but did not allocate
> + * for compression because crypto was not ready, if so then initialize
> + * compression.
> + */
> + if (psinfo && !tfm)
> + allocate_buf_for_compression();
> + return 0;
> +}
> +late_initcall(pstore_compression_late_init);
> +
> module_param(compress, charp, 0444);
> MODULE_PARM_DESC(compress, "Pstore compression to use");
>
> diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
> index bbd1e357c23d..98e48d1a9776 100644
> --- a/fs/pstore/ram.c
> +++ b/fs/pstore/ram.c
> @@ -940,7 +940,7 @@ static int __init ramoops_init(void)
> ramoops_register_dummy();
> return platform_driver_register(&ramoops_driver);
> }
> -late_initcall(ramoops_init);
> +postcore_initcall(ramoops_init);
>
> static void __exit ramoops_exit(void)
> {
>
Yes I could see the early crash dump. Also I tested with different
compression (LZO) instead of deflate just to be sure and it works fine,
thanks :)
Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
next prev parent reply other threads:[~2018-10-17 11:38 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-16 11:38 Crash in msm serial on dragonboard with ftrace bootargs Sai Prakash Ranjan
2018-10-16 11:44 ` Greg Kroah-Hartman
2018-10-16 11:58 ` Sai Prakash Ranjan
2018-10-16 15:29 ` Steven Rostedt
2018-10-16 16:35 ` Sai Prakash Ranjan
2018-10-16 16:57 ` Steven Rostedt
2018-10-16 17:36 ` Sai Prakash Ranjan
2018-10-16 17:48 ` Steven Rostedt
2018-10-16 18:05 ` Sai Prakash Ranjan
2018-10-16 18:16 ` Steven Rostedt
2018-10-16 18:25 ` Sai Prakash Ranjan
2018-10-16 18:41 ` Steven Rostedt
2018-10-16 19:01 ` Sai Prakash Ranjan
2018-10-16 19:03 ` Steven Rostedt
2018-10-16 19:06 ` Sai Prakash Ranjan
2018-10-16 19:15 ` Steven Rostedt
2018-10-16 19:16 ` Steven Rostedt
2018-10-16 19:37 ` Sai Prakash Ranjan
2018-10-16 19:35 ` Sai Prakash Ranjan
2018-10-16 20:51 ` Stephen Boyd
2018-10-17 11:27 ` Sai Prakash Ranjan
2018-10-18 2:33 ` Steven Rostedt
2018-10-18 5:21 ` Sai Prakash Ranjan
2018-10-18 13:17 ` Steven Rostedt
2018-10-19 4:17 ` Joel Fernandes
2018-10-19 6:54 ` Sai Prakash Ranjan
2018-10-19 13:51 ` Steven Rostedt
2018-10-19 14:48 ` Sai Prakash Ranjan
2018-10-19 15:12 ` Steven Rostedt
2018-10-25 14:36 ` saiprakash.ranjan
2018-11-13 9:44 ` Srinivas Kandagatla
2018-11-15 10:33 ` Sai Prakash Ranjan
2018-11-15 10:53 ` Srinivas Kandagatla
2018-11-16 3:39 ` Viresh Kumar
2018-11-16 10:49 ` Sai Prakash Ranjan
2018-10-16 17:02 ` Kees Cook
2018-10-17 10:13 ` Joel Fernandes
2018-10-17 11:38 ` Sai Prakash Ranjan [this message]
2018-10-17 14:49 ` Sai Prakash Ranjan
2018-10-17 17:56 ` Joel Fernandes
2018-10-17 18:25 ` Kees Cook
2018-10-16 23:09 ` Joel Fernandes
2018-10-17 11:53 ` Sai Prakash Ranjan
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