newsoft / ldt_test Goto Github PK

Unfortunately modify_ldt typically isn't enabled on Linux anymore: https://lkml.org/lkml/2015/7/21/759

As a workaround, arch_prctl also exists for the use-case (modifying GS base) shown in ldt64.c.

There is also set_thread_area but it can't be used to change the code segment size since Linux 3.19 (see http://man7.org/linux/man-pages/man2/set_thread_area.2.html). I believe this means it is impossible to run 32 bit code in a 64 bit process now Running 32 bit code can apparently still be done by using existing segments 0x23 / 0x2B: https://stackoverflow.com/questions/41921711/running-32-bit-code-in-64-bit-process-on-linux-memory-access.