Hi Andy, let me first say that I never knew how this code (and the hardware) actually works, I am not sure I even understand what ARCH_SET_.S exactly does ;)
What is even worse, I do not understand your question. So it is not that I am trying to help, I am asking you to help me understand the problem. On 04/29, Andy Lutomirski wrote: > > 1. I read fs_base using ptrace. I think I should get the actual > fs_base without any nonsense. Which fs_base? The member of user_regs_struct? But this structure/layout is just the ABI, so to me it seems correct that getreg() tries to look at ->fs and/or ->fsindex. IOW. getreg(fs) should return the same value as prctl(ARCH_GET_FS) returns if called by the tracee, no? > 2. I read all the regs (PEEKUSER or whatever) and then write then all > back verbatim. At the very least, I think that if I do this > atomically using PTRACE_SETREGSET, the task's state needs to remain > unchanged. Agreed... do you mean this doesn't work? > Since ptrace doesn't seem to have any real concept of > atomic register state changes right now Could you spell please? I can't understand what does "atomically" mean in this context. Oleg.
