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.
regards,
Michael
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
From: Michael Straube
> Sent: 13 April 2022 20:42
>
> 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 */
Probably need an __aligned(8) at the bottom then?
> > /* 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;
> > };
...
>
> 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'd also add a compile-time assert on the size.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)