Re: [PATCH 147/190] Revert "media: dvb: add return value check on Write16"

[Greg Kroah-Hartman]

On Wed, Apr 21, 2021 at 03:00:22PM +0200, Greg Kroah-Hartman wrote:
> This reverts commit 0f787c12ee7b2b41a74594ed158a0112736f4e4e.
> 
> Commits from @umn.edu addresses have been found to be submitted in "bad
> faith" to try to test the kernel community's ability to review "known
> malicious" changes.  The result of these submissions can be found in a
> paper published at the 42nd IEEE Symposium on Security and Privacy
> entitled, "Open Source Insecurity: Stealthily Introducing
> Vulnerabilities via Hypocrite Commits" written by Qiushi Wu (University
> of Minnesota) and Kangjie Lu (University of Minnesota).
> 
> Because of this, all submissions from this group must be reverted from
> the kernel tree and will need to be re-reviewed again to determine if
> they actually are a valid fix.  Until that work is complete, remove this
> change to ensure that no problems are being introduced into the
> codebase.
> 
> Cc: Aditya Pakki <pakki001@xxxxxxx>
> Cc: Sean Young <sean@xxxxxxxx>
> Cc: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
>  drivers/media/dvb-frontends/drxd_hard.c | 30 +++++++++----------------
>  1 file changed, 11 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/media/dvb-frontends/drxd_hard.c b/drivers/media/dvb-frontends/drxd_hard.c
> index a7eb81df88c2..3e3de6badc86 100644
> --- a/drivers/media/dvb-frontends/drxd_hard.c
> +++ b/drivers/media/dvb-frontends/drxd_hard.c
> @@ -1132,8 +1132,6 @@ static int EnableAndResetMB(struct drxd_state *state)
>  
>  static int InitCC(struct drxd_state *state)
>  {
> -	int status = 0;
> -
>  	if (state->osc_clock_freq == 0 ||
>  	    state->osc_clock_freq > 20000 ||
>  	    (state->osc_clock_freq % 4000) != 0) {
> @@ -1141,17 +1139,14 @@ static int InitCC(struct drxd_state *state)
>  		return -1;
>  	}
>  
> -	status |= Write16(state, CC_REG_OSC_MODE__A, CC_REG_OSC_MODE_M20, 0);
> -	status |= Write16(state, CC_REG_PLL_MODE__A,
> -				CC_REG_PLL_MODE_BYPASS_PLL |
> -				CC_REG_PLL_MODE_PUMP_CUR_12, 0);
> -	status |= Write16(state, CC_REG_REF_DIVIDE__A,
> -				state->osc_clock_freq / 4000, 0);
> -	status |= Write16(state, CC_REG_PWD_MODE__A, CC_REG_PWD_MODE_DOWN_PLL,
> -				0);
> -	status |= Write16(state, CC_REG_UPDATE__A, CC_REG_UPDATE_KEY, 0);
> +	Write16(state, CC_REG_OSC_MODE__A, CC_REG_OSC_MODE_M20, 0);
> +	Write16(state, CC_REG_PLL_MODE__A, CC_REG_PLL_MODE_BYPASS_PLL |
> +		CC_REG_PLL_MODE_PUMP_CUR_12, 0);
> +	Write16(state, CC_REG_REF_DIVIDE__A, state->osc_clock_freq / 4000, 0);
> +	Write16(state, CC_REG_PWD_MODE__A, CC_REG_PWD_MODE_DOWN_PLL, 0);
> +	Write16(state, CC_REG_UPDATE__A, CC_REG_UPDATE_KEY, 0);
>  
> -	return status;
> +	return 0;
>  }
>  
>  static int ResetECOD(struct drxd_state *state)
> @@ -1305,10 +1300,7 @@ static int SC_SendCommand(struct drxd_state *state, u16 cmd)
>  	int status = 0, ret;
>  	u16 errCode;
>  
> -	status = Write16(state, SC_RA_RAM_CMD__A, cmd, 0);
> -	if (status < 0)
> -		return status;
> -
> +	Write16(state, SC_RA_RAM_CMD__A, cmd, 0);
>  	SC_WaitForReady(state);
>  
>  	ret = Read16(state, SC_RA_RAM_CMD_ADDR__A, &errCode, 0);
> @@ -1335,9 +1327,9 @@ static int SC_ProcStartCommand(struct drxd_state *state,
>  			break;
>  		}
>  		SC_WaitForReady(state);
> -		status |= Write16(state, SC_RA_RAM_CMD_ADDR__A, subCmd, 0);
> -		status |= Write16(state, SC_RA_RAM_PARAM1__A, param1, 0);
> -		status |= Write16(state, SC_RA_RAM_PARAM0__A, param0, 0);
> +		Write16(state, SC_RA_RAM_CMD_ADDR__A, subCmd, 0);
> +		Write16(state, SC_RA_RAM_PARAM1__A, param1, 0);
> +		Write16(state, SC_RA_RAM_PARAM0__A, param0, 0);
>  
>  		SC_SendCommand(state, SC_RA_RAM_CMD_PROC_START);
>  	} while (0);
> -- 
> 2.31.1
> 

Nothing like continuing to hammer on hardware when accesses to it fail,
and having "-1" be the only error value this driver seems to know, ick.

But this patch is ok, I'll drop it from my series.

greg k-h