[LinuxBIOS] FILO with the USB

Fridel Fainshtein fainshf at gmail.com
Wed Nov 14 20:03:25 CET 2007

Hello all,

It seams that the USB code was taken from the previous version of FILO
but never have been tested.

Some symptoms are
malloc_diag: alloc: 4208 bytes (8 blocks), free: 61320 bytes (1 blocks)
malloc_check: sizes mismatch: 0xa1 vs 0x0 at 00132670
dma_to_td: can not find td

Trying to debug it, I discovered the following piece of code:

void *allot2(size_t size, unsigned int alignment)
	void *addr;
	unsigned long addrval;

	addrval=(unsigned long)addr;
	addrval+=alignment+1; //  0x12345600 + 0xff + 1
	addrval&=~alignment;  //  0x12345700
	*(void * *)(addrval-sizeof(unsigned long))=addr;
	return (void *)addrval;

void forget2(void *mem)
	unsigned long addr=(unsigned long)mem;
	addr-=sizeof(unsigned long);
	free((void *)(*(unsigned long *)addr));

I have 2 questions:
if size = 8 and alignment=256, it writes outside malloc allocation, isn't it?
What was the meaning of the code?


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