Hi.... On Wed, Sep 3, 2008 at 4:21 AM, Eric Lacombe <eric.lacombe@xxxxxxxxxxxxxxxxx> wrote: > Hello, > > I've some questions about IA-32e in Linux. > > - What is the FS and GS segments role inside the kernel ? > (I was thinking about thread local storage) correct..it points to current process' start of TLS segment > - When I do a "mov %fs ..." instruction (in a module), it seems that %fs is > equal to 0 (idem for %gs). Are these registers not always filled ? probably in kernel space, fs/gs has no meaning...or maybe since your module is currently running on behalf on non TLS process, thus fs/gs is zero. > - What is the purpose of MSR_FS_BASE and MSR_GS_BASE ? > (I thought they were filled with "gdt[fs_entry].base") ehm just guessing, they were looked up when a process does SYSENTER/SYSCALL? regards, Mulyadi. -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
