Re: [PATCH resend v2 3/5] libata-scsi: use u8 array to store mode page copy

From	Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH resend v2 3/5] libata-scsi: use u8 array to store mode page copy
Date	2016-07-22 12:00 +0200
Message-ID	<rXFpn-46k-11@gated-at.bofh.it> (permalink)
References	<rXu0V-4Lj-3@gated-at.bofh.it> <rXvzI-5X0-3@gated-at.bofh.it> <rXvzI-5X0-5@gated-at.bofh.it> <rXvzI-5X0-1@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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Hello.

On 7/22/2016 2:29 AM, tom.ty89@gmail.com wrote:

> From: Tom Yan <tom.ty89@gmail.com>
>
> ata_mselect_*() would initialize a char array for storing a copy of
> the current mode page. However, char could be signed char. In that
> case, bytes larger than 127 would be converted to negative number.
>
> For example, 0xff from def_control_mpage[] would become -1. This
> prevented ata_mselect_control() from working at all, since when it
> did the read-only bits check, there would always be a mismatch.
>
> Signed-off-by: Tom Yan <tom.ty89@gmail.com>
>
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index 4a4e6f1..a28e2ea94 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -3610,7 +3610,7 @@ static int ata_mselect_caching(struct ata_queued_cmd *qc,
>  {
>  	struct ata_taskfile *tf = &qc->tf;
>  	struct ata_device *dev = qc->dev;
> -	char mpage[CACHE_MPAGE_LEN];
> +	u8 mpage[CACHE_MPAGE_LEN];
>  	u8 wce, mask;
>  	int i;
>
> @@ -3668,7 +3668,7 @@ static int ata_mselect_control(struct ata_queued_cmd *qc,
>  			       const u8 *buf, int len, u16 *fp)
>  {
>  	struct ata_device *dev = qc->dev;
> -	char mpage[CONTROL_MPAGE_LEN];
> +        u8 mpage[CONTROL_MPAGE_LEN];

    Indent with tabs please, as above.

[...]

MBR, Sergei

Thread

[PATCH resend 2/5] libata-scsi: fix read-only bits checking in ata_mselect_*() tom.ty89@gmail.com - 2016-07-21 20:50 +0200
  [PATCH resend 3/5] libata-scsi: fix overflow in mode page copy tom.ty89@gmail.com - 2016-07-21 20:50 +0200
    [PATCH resend 4/5] libata-scsi: have all checks done before calling ata_mselect_*() tom.ty89@gmail.com - 2016-07-21 20:50 +0200
    Re: [PATCH resend 3/5] libata-scsi: fix overflow in mode page copy Tejun Heo <tj@kernel.org> - 2016-07-21 23:20 +0200
      Re: [PATCH resend 3/5] libata-scsi: fix overflow in mode page copy Tom Yan <tom.ty89@gmail.com> - 2016-07-21 23:40 +0200
        Re: [PATCH resend 3/5] libata-scsi: fix overflow in mode page copy Tejun Heo <tj@kernel.org> - 2016-07-21 23:50 +0200
          [PATCH resend v2 3/5] libata-scsi: use u8 array to store mode page copy tom.ty89@gmail.com - 2016-07-22 01:30 +0200
            Re: [PATCH resend v2 3/5] libata-scsi: use u8 array to store mode  page copy Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> - 2016-07-22 12:00 +0200
              Re: [PATCH resend v2 3/5] libata-scsi: use u8 array to store mode  page copy Tom Yan <tom.ty89@gmail.com> - 2016-07-22 20:30 +0200
                [PATCH resend v3 3/5] libata-scsi: use u8 array to store mode page copy tom.ty89@gmail.com - 2016-07-22 20:40 +0200
          [PATCH resend v2 3/5] libata-scsi: use u8 array to store mode page copy tom.ty89@gmail.com - 2016-07-22 01:40 +0200
  Re: [PATCH resend 2/5] libata-scsi: fix read-only bits checking in ata_mselect_*() Tom Yan <tom.ty89@gmail.com> - 2016-07-22 01:30 +0200
    [PATCH resend v2 2/5] libata-scsi: fix read-only bits checking in ata_mselect_*() tom.ty89@gmail.com - 2016-07-22 01:30 +0200
    [PATCH resend v2 2/5] libata-scsi: fix read-only bits checking in ata_mselect_*() tom.ty89@gmail.com - 2016-07-22 01:40 +0200

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