We use two commands to get task registers safely. The first command
blocked signals, then crtools dumped registers and all per-thread data
and the the second command unblocks signals.
Currently signals can be blocked with help SETSIGMASK, so we need only
one command to dump per-thread data.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Pending signals should be saved, so signals should be blocked.
Signals are blocked for EACH command, because a chance of destroying a
process state should be a small as possible.
At the end there will only two "trapped" commands -- to dump thread
and to start daemon in parasite, so this doesn't add significant
overheads.
If crtools is killed between two commands, a dumped process will run
continue.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The initilization stage is not good for that, because it can fail.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
tcp_repair_off implicitly modifies SO_REUSEADDR option
inside the kernel (thanks avagin@ for pointing this
feature out) thus if we are to rollback and restore
the former settings of socket -- don't forget to
repair this particular one.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
CC: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
To restore SAS we have two ways:
- call for sigaltstack explicitly in restorer.c right before we call for sigreturn
- pass stack value to sigreturn call and allow the kernel to restore stack for us
Since second way is a simplier one -- we stick with it.
[alekskartashov@: use RT_SIGFRAME_UC]
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
CC: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
[alekskartashov@: use encode_pointer]
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
CC: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
- include "protobuf/core.pb-c.h" for CoreEntry definition
- gather structure predeclaration on top
- move general comment on top as well
- add extern for construct_sigframe helper
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Number of rlimits may vary depending on system version
criu is compiled against. So we use rst-allocator to
carry all limits read from file.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
1st stage is -- creating the timers. It may fail if kernel
allocated IDs in a manner we don't expect or runs out of
memory.
2nd stage is -- arm the timers. It cannot fail, since we've
validated the timespecs in advance and should happen after
we've waited for all the other tasks to complete the restore.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Since *all* of them just call do_dump_gen_file with proper ops,
just call one directly. Compacts the code.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
In commit 2f5df09da587d3dd4002b25fccc39bf1255b1d0a
we included asm/type.h for bool definition. This
is fine in terms of CRIU but makes cpt2 converter
to carry the whole asm/type.h, sometimes causing
error due to confilicting definitions.
So lets be simplier and include <stdbool.h> instead.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
After creating namespaces we may need to apply some configuration.
For example uid and gid maps should be applied in this moment.
This script should be executed from crtools, but namespaces are created
in a root process, so we need to add a new stage for synchronizing.
v2: use a separate stage instead of socketpair.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
- gather structs at top
- add externs
- align arguments in declarations
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Tested-by: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It will be needed in x86/ code.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Tested-by: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
because we want to know when one of the sides closed its point.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This patch fixes build error due to lack of bool type. It can be fixed adding
include file.
In file included from arch/arm/vdso-pie.c:3:0:
include/vdso.h:41:1: error: unknown type name ‘bool’
include/vdso.h:93:1: error: unknown type name ‘bool’
Signed-off-by: Chanho Park <chanho61.park@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>
Acked-by: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
While being extracting common part of image descriptors to separate file
this declaration escaped me.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Move image object descriptors to own image-desc
file(s). This allow to reuse the code in other tools.
I had to move show declarations to cr-show.h as well.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Move protobuf object descriptors to own protobuf-desc
file(s). This allow to reuse the code in other tools.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We're about to implement functionality to allow parasite to
return to dumpee via sigreturn in case crtools suddenly detached
from it. Thus, we need a space for sigframe in shared area.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This mask should be put into sigframe (used by parasite, coming
soon) thus we have to pull one from dumpee early.
Plus, check that signals are blocked for each thread separately
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Parasite daemon mode it quite tricky. One may consider
it as consisting of two parts
- daemon mode for thread leader
- daemon mode for regular threads
Thread leader daemon
--------------------
Once thread leader parasite code switched initialized,
it starts spinning on socket listening for commands
to handle.
If the command destination is the thread leader itself it
handles it and replies back the ack to the caller (iow
the main crtools code).
If the recepient is not thread leader but one of threads,
then thread leader wakes up the thread by futex and makes
it to handle the command waiting on futex for result. Once
result obtained, the ack is being sending back to caller.
Thread daemon
-------------
On initialization thread daemon starts waiting a command on futex.
The futex is triggered by thread leader daemon when command received.
Once command is received and handled, the result is reported back to
the thread leader daemon, which in turn send ack message.
Both thread-leader and regular threads require own stack to operate
on since they all are present in memory simultaneously. Thus we use
call_daemon_thread() helper which takes care of providing stack
to the callee.
TODO:
- ARM requires own wrappers on damonize/trap low-level code,
at moment x86-64 is only covered
v2: remove PARASITE_CMD_DAEMONIZED and s->ack
parasite: use a propper command for getting ack
Fixed-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Parasite daemon mode might be considered as a series
of network messages sent from main crtools module to
parasite daemon which spins on a socket waiting for
command to handle.
Simple command handling session might look as
crtools daemon
| | |
| ---> command message ---> | |
| | ---> receive command ---> |
| | .... |
| | handle command |
| | .... |
| | <--- send ack <--- |
| <--- receive ack <--- | |
| | |
v v v
time
where, in case of multithread application [handle command] stage
includes waking up of children threads via futexes, wait until
handling complete and only then send ack back to ctrools module.
This patch brings in description of command message as
struct ctl_msg {
unsigned int id; /* command recipient */
unsigned int cmd; /* command itself */
unsigned int ack; /* ack on command */
int err; /* error code on reply */
};
For example, in case of dumpee being with pid 2 and acquiring
to handle PARASITE_CMD_DUMP_MISC, the command/ack series will look
as
cmd-msg
-------
.id = 2,
.cmd = PARASITE_CMD_DUMP_MISC,
.ack = 0,
.err = 0,
ack-msg
-------
.id = 2,
.cmd = PARASITE_CMD_DUMP_MISC,
.ack = PARASITE_CMD_DUMP_MISC,
.err = 0
in case if error happened in parasite, the @err field set accordingly.
For convenience ctl_msg_cmd()/ctl_msg_ack() macros are provided
for control message generations.
v2: delete futex_t ack from tid_state_s
Fixed-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
They are relying on trap being issued at the end of execution
so to distinguish it with future daemon mode add "trap" postfix
to them.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
When we try to execute a parasite code, a signal can be started
handling, so we need to update a task registers, which will be saved in
a core file.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It will be used for executed parasite as a daemon.
What we have previously -- the stack has been preallocated in parasite
blob itself and bootstrap procedure calculated the value needed for %rsp.
With this patch applied we provide every thread own stack as:
- find out how many threads are present
- calculate the summary size of all stacks
- when we ask dumpee to provide us memory area needed to run
parasite code, we pass summary size needed for everything
- when parasite code is asked to run we calculate %rsp needed
taking into account the thread number (ie offsets) and then
setup proper %rsp via ptrace call, instead of calculating it
in bootstrap parasite code
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Now we restore thread registers immediately after a command,
but when we will execute a parasite, it will be impossible.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We have three arrays for thread related data: item->threads,
parasite_ctl->thread and tid_state in parasite.
With this patch a thread will have the same index in all arrays.
The zero index is used for a thread leader.
In this case we don't need to search thread_state in parasite.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
When parasite daemon mode will be implemented we get deprived of ability
to fetch registers at the late moment of dumping as we were, thus just
bind CoreEntry to pstree item and allocate CoreEntry'ies for every
thread found, once process tree is in seized state.
Then immediately fill CoreEntry'ies with registers. We use prctl
opcode for that but fetch a complete set of registers including
FPU state, and convert them into protobuf format.
Zombie tasks remains untouched, we allocate CoreEntry for them
right at moment of dumping becuase we don't need registers there
to be written on disk.
This way get_task_regs no longer need parasite_ctl argument
and it's zapped.
Still parasite_ctl has own copy of general registers set but
this is because we need them to be in cpu native format unlike
ones kept in CoreEntry.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
