Re: [PATCH 1/3] uprobes: Change write_opcode() to use FOLL_FORCE

2012-09-25 Thread Srikar Dronamraju
* Oleg Nesterov [2012-09-16 19:52:42]: > write_opcode()->get_user_pages() needs FOLL_FORCE to ensure we can > read the page even if the probed task did mprotect(PROT_NONE) after > uprobe_register(). Without FOLL_WRITE, FOLL_FORCE doesn't have any > side effect but allows to read the !VM_READ memo

[PATCH 1/3] uprobes: Change write_opcode() to use FOLL_FORCE

2012-09-16 Thread Oleg Nesterov
write_opcode()->get_user_pages() needs FOLL_FORCE to ensure we can read the page even if the probed task did mprotect(PROT_NONE) after uprobe_register(). Without FOLL_WRITE, FOLL_FORCE doesn't have any side effect but allows to read the !VM_READ memory. Otherwiese the subsequent uprobe_unregister(