Linux: Core Dump Scanning HDHR QAM

[MrD]

Originally Posted by Narflex

I have an idea what the problem is here if somebody wants to try it out.

In native/ax/Native2.0/NativeCore/TSCRC32.c

I think the 'unsigned long' data types should be changed to be uint32_t (proper includes will need to be added for that). What could be happening is that the unsigned long data type now has a 64 bit value on a 64 bit platform (Whereas it was 32 bits in size on a 32 bit platform). So we start off with this:

unsigned long crc = 0xffffffff;

then when it does this:

crc = (crc << 8) ^ ts_crc32_table[ (crc >> 24) ^ (*p_byte) ];

That first left shift of 8 bits won't cause any to drop off (if unsigned longs are 64 bits now)...and it'll have stuff in the higher 32 bits. That also means then when it does the 24 bit right shift the next time around in the loop (or maybe 2 more times)...that there'll be data beyond the lowest 8 bits, making the value larger than 255 which will then walk off the array that stores the CRC values (and by a very large amount, enough to make Linux unhappy).

Doh! It's been too long since I've looked at C code. I completely missed the table dereference would go off into the woods with an out of range index!

[coppit]

Has the fix hit the repo yet? I can prep a merge request if needed.

[Taddeusz]

Just did a pull request for this.

[Narflex]

Fix is merged now, thanks.