Yu-cheng, Am 20.06.2017 um 20:17 schrieb Richard Weinberger: > Yu-cheng, > > Am 20.06.2017 um 20:04 schrieb Yu-cheng Yu: >>>> So to summarize: >>>> >>>> - PTRACE_GETREGSET with NT_X86_XSTATE gets 832 and return 832, with no >>>> error. >>>> >>>> - PTRACE_SETREGSET get 832 (sizeof struct _xstate) but wants at least >>>> 1088, otherwise it will fail with -EFAULT (why not -EINVAL?) >>>> >>>> Ideas? >> >> We considered allowing a partial XSAVE buffer for PTRACE_SETREGSET, but >> it was that the XSAVE instruction requires a full-size buffer led to >> this choice. Using a smaller buffer for XSAVE causes a fault. > > So, this code is not supposed to work? > > iov.iov_base = fp_regs; > iov.iov_len = sizeof(struct _xstate); > ptrace(PTRACE_GETREGSET, pid, NT_X86_XSTATE, &iov); > ptrace(PTRACE_SETREGSET, pid, NT_X86_XSTATE, &iov); > > This is what UML does and on Thomas's new Laptop PTRACE_SETREGSET is failing. Hmm, I think we need to do what gdb does, it uses a buffer of size X86_XSTATE_MAX_SIZE. Thanks, //richard -- To unsubscribe from this list: send the line "unsubscribe linux-x86_64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
