linux-kernel - Re: [PATCH v4 01/27] bus: mhi: Fix pm

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <6fc89860-9eea-630c-f193-272bf436ad81@linaro.org>
Date:   Mon, 28 Feb 2022 09:30:26 -0600
From:   Alex Elder <elder@...aro.org>
To:     Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>,
        mhi@...ts.linux.dev
Cc:     quic_hemantk@...cinc.com, quic_bbhatt@...cinc.com,
        quic_jhugo@...cinc.com, vinod.koul@...aro.org,
        bjorn.andersson@...aro.org, dmitry.baryshkov@...aro.org,
        quic_vbadigan@...cinc.com, quic_cang@...cinc.com,
        quic_skananth@...cinc.com, linux-arm-msm@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Paul Davey <paul.davey@...iedtelesis.co.nz>,
        Manivannan Sadhasivam <mani@...nel.org>,
        Hemant Kumar <hemantk@...eaurora.org>, stable@...r.kernel.org
Subject: Re: [PATCH v4 01/27] bus: mhi: Fix pm_state conversion to string

On 2/28/22 6:43 AM, Manivannan Sadhasivam wrote:
> From: Paul Davey <paul.davey@...iedtelesis.co.nz>
> 
> On big endian architectures the mhi debugfs files which report pm state
> give "Invalid State" for all states.  This is caused by using
> find_last_bit which takes an unsigned long* while the state is passed in
> as an enum mhi_pm_state which will be of int size.
> 
> Fix by using __fls to pass the value of state instead of find_last_bit.
> 
> Also the current API expects "mhi_pm_state" enumerator as the function
> argument but the function only works with bitmasks. So as Alex suggested,
> let's change the argument to u32 to avoid confusion.

(Grumble grumble too much static data in header file.)

Reviewed-by: Alex Elder <elder@...aro.org>

> Fixes: a6e2e3522f29 ("bus: mhi: core: Add support for PM state transitions")
> Signed-off-by: Paul Davey <paul.davey@...iedtelesis.co.nz>
> Reviewed-by: Manivannan Sadhasivam <mani@...nel.org>
> Reviewed-by: Hemant Kumar <hemantk@...eaurora.org>
> Cc: stable@...r.kernel.org
> [mani: changed the function argument to u32]
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
> ---
>   drivers/bus/mhi/core/init.c     | 10 ++++++----
>   drivers/bus/mhi/core/internal.h |  2 +-
>   2 files changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
> index 046f407dc5d6..09394a1c29ec 100644
> --- a/drivers/bus/mhi/core/init.c
> +++ b/drivers/bus/mhi/core/init.c
> @@ -77,12 +77,14 @@ static const char * const mhi_pm_state_str[] = {
>   	[MHI_PM_STATE_LD_ERR_FATAL_DETECT] = "Linkdown or Error Fatal Detect",
>   };
>   
> -const char *to_mhi_pm_state_str(enum mhi_pm_state state)
> +const char *to_mhi_pm_state_str(u32 state)
>   {
> -	unsigned long pm_state = state;
> -	int index = find_last_bit(&pm_state, 32);
> +	int index;
>   
> -	if (index >= ARRAY_SIZE(mhi_pm_state_str))
> +	if (state)
> +		index = __fls(state);
> +
> +	if (!state || index >= ARRAY_SIZE(mhi_pm_state_str))
>   		return "Invalid State";
>   
>   	return mhi_pm_state_str[index];
> diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h
> index e2e10474a9d9..3508cbbf555d 100644
> --- a/drivers/bus/mhi/core/internal.h
> +++ b/drivers/bus/mhi/core/internal.h
> @@ -622,7 +622,7 @@ void mhi_free_bhie_table(struct mhi_controller *mhi_cntrl,
>   enum mhi_pm_state __must_check mhi_tryset_pm_state(
>   					struct mhi_controller *mhi_cntrl,
>   					enum mhi_pm_state state);
> -const char *to_mhi_pm_state_str(enum mhi_pm_state state);
> +const char *to_mhi_pm_state_str(u32 state);
>   int mhi_queue_state_transition(struct mhi_controller *mhi_cntrl,
>   			       enum dev_st_transition state);
>   void mhi_pm_st_worker(struct work_struct *work);