On Thu, February 9, 2012 17:00, H.J. Lu wrote: > GDB uses CS value to tell ia32 process from x86-64 process. Are there any cases when this doesn't work? Someone said Xen can have different CS values, but looking at the source it seems it's using the same ones, at least with a Linux hypervisor. So perhaps it was KVM. Looking at the header it seems paravirtualisation uses different cs values. On the upside, it seems we can just use that user_64bit_mode() to know whether it is 32 or 64 bit mode, so adding a bit telling the process mode is easier than I thought. Currently there is a need to tell if the 32 or 64-bit syscall path is being taken, which is independent of the process mode. > At minimum, we need a bit in CS for GDB. But any changes > will break old GDB. Would adding bits to the upper 32-bit of rflags break GDB? Do you also need a way to know whether the kernel was entered via int 0x80, SYSCALL32/64 or SYSENTER? Greetings, Indan -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
