Anshuman Khandual <khand...@linux.vnet.ibm.com> wrote on 23.03.2015 11:34:30:
> > With that in mind, do we have a way to set the top 32bits of the MSR > > (which contain the TM bits) when ptracing 32 bit processes? I can't > > find anything like that in this patch set. > > No, we dont have that yet. When ptracing in 32-bit mode the MSR value > which can be viewed or set from the user space through PTRACE_GETREGS > PTRACE_SETREGS call is it's lower 32 bits only. Either we can club > the upper 32 bits of MSR as part of one of the ELF core notes we are > adding in the patch series or we can create one more separate ELF core > note for that purpose. Let me know your opinion on this. I'm not sure I understand this. I thought we had the following: - If the process calling ptrace is itself 64-bit (which is how GDB is built on all current Linux distributions), then PTRACE_GETREGS etc. will *always* operate on 64-bit register sets, even if the target process is 32-bit. - If the process calling ptrace is 32-bit, then PTRACE_GETREGS will operate on 32-bit register sets. However, there is a separate PTRACE_GETREGS64 / PTRACE_SETREGS64 call that will also provide the opportunity to operate on the full 64-bit register set. Both apply independently of whether the target process is 32-bit or 64-bit. Is this not correct? Bye, Ulrich -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
