Method brk

source/kernel/kprocess.cpp:1143–1166

}

U32 KProcess::brk(KThread* thread, U32 address) {    
    if (address > this->brkEnd) {
        U32 len = address-this->brkEnd;
        U32 alreadyAllocated = K_ROUND_UP_TO_PAGE(this->brkEnd) - this->brkEnd;

        if (len<=alreadyAllocated) {
            this->brkEnd+=len;
        } else {
            U32 aligned = (this->brkEnd+4095) & 0xFFFFF000;
            U32 startPage = aligned >> K_PAGE_SHIFT;
            U32 stopPage = startPage+((len-alreadyAllocated+K_PAGE_SIZE-1)>>K_PAGE_SHIFT);

            for (U32 i=startPage;i<=stopPage;i++) {
                if (this->memory->isPageAllocated(i)) {
                    return -K_ENOMEM;
                }
            }
            if (memory->mmap(thread, aligned, len - alreadyAllocated, K_PROT_READ | K_PROT_WRITE | K_PROT_EXEC, K_MAP_PRIVATE | K_MAP_ANONYMOUS | K_MAP_FIXED_NOREPLACE, -1, 0)==aligned) {
                this->brkEnd+=len;
            }				
        }
    }
    return this->brkEnd; // intentional, should return the new end, even though the libc brk returns the old value
}

U32 KProcess::ioctl(KThread* thread, FD fildes, U32 request) {
    KFileDescriptorPtr fd = this->getFileDescriptor(fildes);