Re: staging: r8188eu: struct rt_firmware_header issues

[Larry Finger]

On 4/13/22 14:42, Michael Straube wrote:
> On 4/13/22 18:27, Michael Straube wrote:
> > Hi all,
> >
> > I think the rt_firmware_hdr structure in rtw_fw.c has some issues.
> >
> >
> > struct rt_firmware_hdr {
> >      /*  8-byte alinment required */
> >      /*  LONG WORD 0 ---- */
> >      __le16        Signature;    /* 92C0: test chip; 92C,
> >                       * 88C0: test chip; 88C1: MP A-cut;
> >                       * 92C1: MP A-cut */
> >      u8        Category;    /*  AP/NIC and USB/PCI */
> >      u8        Function;    /*  Reserved for different FW function
> >                       *  indcation, for further use when
> >                       *  driver needs to download different
> >                       *  FW for different conditions */
> >      __le16        Version;    /*  FW Version */
> >      u8        Subversion;    /*  FW Subversion, default 0x00 */
> >      u16        Rsvd1;
> >
> >      /*  LONG WORD 1 ---- */
> >      u8        Month;    /*  Release time Month field */
> >      u8        Date;    /*  Release time Date field */
> >      u8        Hour;    /*  Release time Hour field */
> >      u8        Minute;    /*  Release time Minute field */
> >      __le16        RamCodeSize;    /*  The size of RAM code */
> >      u8        Foundry;
> >      u8        Rsvd2;
> >
> >      /*  LONG WORD 2 ---- */
> >      __le32        SvnIdx;    /*  The SVN entry index */
> >      u32        Rsvd3;
> >
> >      /*  LONG WORD 3 ---- */
> >      u32        Rsvd4;
> >      u32        Rsvd5;
> > };
> >
> >
> > Then we have in rtl8188e_firmware_download():
> >
> >
> >      fwhdr = (struct rt_firmware_hdr *)dvobj->firmware.data;
> >
> >      <snip>
> >
> >      if (IS_FW_HEADER_EXIST(fwhdr)) {
> >          /*  Shift 32 bytes for FW header */
> >          fw_data = fw_data + 32;
> >          fw_size = fw_size - 32;
> >      }
> >
> > We add/sub 32 bytes but the size of struct rt_firmware_hdr is actually
> > 33 bytes. I noticed this when I wanted to replace:
> >
> >          fw_data = fw_data + 32;
> >          fw_size = fw_size - 32;
> >
> > with:
> >          fw_data = fw_data + sizeof(struct rt_firmware_hdr);
> >          fw_size = fw_size - sizeof(struct rt_firmware_hdr);;
> >
> > To me it looks add/sub 32 is correct here but the struct is
> > wrong. I don't know if the firmware for this driver is so much different
> > from firmware for the drivers in drivers/net/wireless/realtek/rtlwifi.
> > They use a struct of size 32.
> >
> > Also, souldn't the u16 and u32 variables in the struct be __le16 and
> > __le32 ?
> >
> > I wonder if we can just use the rtlwifi_firmware_header structure from
> > drivers/net/wireless/realtek/rtlwifi/wifi.h ?
> >
> > Comments from people with better knowledge appreciated. :)
> >
> > regards,
> > Michael
>
> Ok, I figured it out by looking at the hexdumps of firmware files. The
> field Rsvd1 should be u8 instead of u16. I'll prepare a patch for this.

I agree. I had prepared an analysis, but did not get it mailed before I got this 
one.

Larry