Dmitry Safonov d4c02f2eb1 compel: kill self-unmap in parasite ... Why should we have self-unmapping code in parasite? It looks like, we can drop this code using simple sys_unmap() injection (like that I did for `criu exec` action and for cases where we failed to insert parasite by some reason, but still need to unmap remotes). It's an RFC, so just a suggestion - maybe I miss something you have in mind - please, describe that/those things. My motivation is: - less code, defined commands for PIE, one BUG() less, one jump to PIE less - I'm making one 64-bit parasite on x86 instead of two 32 and 64 bit. It works (branch 32-one-parasite) with long-jump in the beginning to 64-bit code from 32-bit task. On parasite curing it sig-returns from 64-bit parasite to 32-bit task, this point we're trapping in CRIU. After that we command parasite to unmap itself, so it long-jumps again to parasite 64-bit code, unmaps, we caught task after sys_unmap and the task is with 64-bit CS. We can't set 32-bit registers after this - kernel checks that registers set is the same on PTRACE_SETREGSET: > > static int ptrace_regset(struct task_struct *task, int req, unsigned int type, > > struct iovec *kiov) ... > > if (!regset || (kiov->iov_len % regset->size) != 0) > > return -EINVAL; So, to return again to 32-bit task I need sigreturn() again or add long-jump with 32-bit CS. I've disable that for 32-bit testing with (in compel_cure_remote): - if (ctl->addr_cmd) { + if (ctl->addr_cmd && user_regs_native(&ctl->orig.regs)) { And it works. It also works for native tasks, so why should we keep it? travis-ci: success for compel: kill self-unmap in parasite Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@virtuozzo.com> Cc: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com> Acked-by: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com> Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>		2017-03-15 00:06:14 +03:00
..
fds.c	compel: plugins -- Merge fds plugin into std	2017-03-15 00:06:13 +03:00
infect.c	compel: kill self-unmap in parasite	2017-03-15 00:06:14 +03:00
log.c	compel: plugins,std -- Move in log engine from criu pie	2017-03-15 00:06:09 +03:00
std.c	compel: Remove criu's int.h from infect	2017-03-15 00:06:02 +03:00
string.c	compel: plugins,std -- Implement generic std_memcpy	2017-03-15 00:06:07 +03:00