OK, now that I've spent a couple weeks looking at Linux memory management, can someone please help me straighten this out. First, I have a requirement to "unobtrusively" hot-patch instruction code ( and probably data also ) segments in memory. I've decided that the best way to do this is to mmap device memory of a pseudo-device module to both the patching process and the target process. To the patching process it can be viewed as just RW data memory, but to the target process it must look like read-only executable. In addition I have found the find_task_by_pid() for getting the process descriptor for the target process. So... 1. Can I copy off the current task pointer and substitute the task pointer returned by find_task_by_pid() (in the pseudo-device mmap() call), and do remap_page_range() to map the memory to the target process? 2. Do I need to set task->has_cpu or any other controls to have the remap work? 3. The book "Understanding the Linux Kernel" has so many references to vm_area_struct that I'm confused as to when this memory area gets allocated, let alone who it belongs to in the mmap() call. I had thought I'd just do get_free_page() and mmap that address, but everything seems very convoluted with so many references in the API's to vm_area_struct: I can't seem to keep straight just what VM is supposed to be passed in the mmap() call, where it comes from, etc. Is this the [task]->active_mm->mmap vm_area_struct or should I look for another? HELP! Code deadline was supposed to be noon today ( I'm screwed ) and this is the main hitch holding me back. BTW, I can't tell why I'm doing this, so please don't ask... Keith Siders Software Engineer Toshiba America Consumer Products, Inc. Advanced Television Technology Center 801 Royal Parkway, Suite 100 Nashville, Tennessee 37214 Phone: (615) 257-4050 Fax: (615) 453-7880
