The register R12 has a special meaning when syscalls are hooked
with ptrace() in ARM that results in a dumpee context corruption
on an injected blob unmap. Note that this patch doesn't solve
the problem entirely since the compiler may corrupt the register
before issuing a call to the routine sys_munmap(); however
we assume that a sufficiently decent compiler doesn't.
Signed-off-by: Alexander Kartashov <alekskartashov@parallels.com>
Tested-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
I don't know a reason, when accept() fails once and then goes back to
normal work.
Cc: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This vma looks like VSYSCALL on x86. We don't need to dump and restore it.
Currently this vma is dumped and restored as a private vma, but it is not
remmaped in a correct place:
Restore
--- dump/pipe00/6392/1/dump.maps 2013-09-23 12:49:19.436816192 +0000
+++ dump/pipe00/6392/1/restore.maps 2013-09-23 12:49:20.276766356 +0000
@@ -6,5 +6,6 @@ e05000-e26000
4009d000-4009f000
400a0000-400aa000
400b8000-401e7000
+b6d6f000-b6d70000
be838000-be859000
ffff0000-ffff1000
ERROR: Sets of mappings differ:
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This patch detects the race, when a signal hanler could be executed
during restore.
More details are in: 5d18eca restorer: Block signals early
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Some VMA-s can be merged on restore. For example, If a process maps
VMA1, VMA2 and then VMA3 between the previous ones.
|VMA1|VMA3|VMA2|
The VMA3 will be merged only with VMA1, but all three VMA-s will be
merged on restore, because they are mmaped in a correct order VMA1,
VMA3, VMA2.
Due to this issue, we have a small script for merging continuous VMA-s.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
All process VMA-s are in "premmaped area". All restorer stuff are in
bootstap "area", so we have two areas.
So we don't need to unmap extra VMA-s one by one. We can call munmap
three times for the region before the first area, for the hole between
areas and for the region after the second area.
The old scheme didn't work, because the list of VMA-s can be changed
after collecting. It can be due to memory allocations by libc or due to
increased stack.
v2: improve readability at the expense of beautiness
v3: print return code of munmap in error messages
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This patch adds a new parasite command, which unmaps the parasite blob.
This command never returns and the criu process traps the target process
on the exit from the munmap syscall.
v2: rename the function for unmaping a parasite blob to not intersects
with criu's functions.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This patch adds a function for removing the restorer blob. This function
never returns and the process must be trapped on the exit from the
munmap syscall.
v2: * release parasite_ctl sturcture and use the new interface of
parasite_prep_ctl
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
A task is stopped here for unmaping restorer blob and restoring a state.
The method is the same as for parasite. CRIU attaches to processes via
ptrace and start to trace all syscalls.
v2: don't use a software breakpoint
v3: stop all thread on the exit from sigreturn
v4: attach to each thread
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
parse_thread allocated a buffer for threads and then it initialized read
pid for each thread.
Now we want to use it on restore and in this moment we already have
a buffer with initialized virt pid-s, so we need to initialize read
pid-s only.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It will be used in cr-restore.c for stopping threads on the exit from
sigreturn.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The munmap syscall must be executed from a process memory. The code can
be injected in memory and then removed. But we can avoid all these
actions, if the code will be in the blob and a process will be trapped
on the exit from the munmap syscall.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This feature will be used for unmaping restorer blobs. All reqired code
will be in the blob.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
All processes must be started by PTRACE_SYSCALL. The function calls wait
in a loop and if a process on the exit from the required syscall, it
is stopped, otherwise it will be reexecuted by PTRACE_SYSCALL.
The function doesn't know, which processes should be trapped, so
you should care, that wait() will not catch someone else.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This patch adds nothing new, just splits the existant function.
Currently a parasite stopped on sigreturn for unmaping a parasite blob.
The same scheme will be used for restorer blob and this function will be
used to stop on exit from the munmap syscall.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
For the root task the clone syscall returns the pid in criu's pidns,
but for other processes the clone syscall returns PID in the restored
namespace.
The /proc/self link contains the PID value of the current process, so if
we want to determing the PID in a criu's pidns, we should use criu's
/proc.
v2: readlink() does not append a null byte to buf, so we must do that
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
A pstree item will contain pid and state. Both these properties will be
determined after creating processes and will be used from the
controlling proces.
v2: fix the error path
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We was going to block a connections in both directions (v0.6-97-g0a1b70b),
but both iptable rules are added in the INPUT table. It's wrong, because
the rule must be added to the OUTPUT table to block locally-generated packets
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
SO_SNDBUF and SO_RCVBUF sets a double input value, because
"Linux reserves half of te socket buffer for metadata."
So if a process is suspended/restored many times, a socket buffer
size is doubled on each iteration and in a one moment it is overflowed.
Very likely the program hangs in such situation, because the socket with
negative buffer size is unusable.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
An error occurs when trying to build crtools on ARM systems
with perl versions earlier than 5.13.2 due to lack of /r modifier.
% make
...
GEN arch/arm/syscalls.S
Bareword found where operator expected at arch/arm/gen-syscalls.pl line 8, near "s/.*include\///gr"
Bareword found where operator expected at arch/arm/gen-syscalls.pl line 10, near "s/.*include\///gr"
Bareword found where operator expected at arch/arm/gen-syscalls.pl line 13, near "s/.*include\///gr"
Bareword found where operator expected at arch/arm/gen-syscalls.pl line 16, near "tr/.-/_/r"
Bareword found where operator expected at arch/arm/gen-syscalls.pl line 17, near "tr/.-/_/r"
syntax error at arch/arm/gen-syscalls.pl line 8, near "s/.*include\///gr"
syntax error at arch/arm/gen-syscalls.pl line 10, near "s/.*include\///gr"
syntax error at arch/arm/gen-syscalls.pl line 13, near "s/.*include\///gr"
syntax error at arch/arm/gen-syscalls.pl line 16, near "tr/.-/_/r"
syntax error at arch/arm/gen-syscalls.pl line 17, near "tr/.-/_/r"
BEGIN not safe after errors--compilation aborted at arch/arm/gen-syscalls.pl line 60.
make[1]: *** No rule to make target `arch/arm/syscalls.S', needed by `arch/arm/syscalls.o'. Stop.
Signed-off-by: Alexander Kolesen <kolesen.a@gmail.com>
Acked-by: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
When service/page server becomes daemon, we may need to know it's pid.
Signed-off-by: Ruslan Kuprieiev<kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Now we don't have generic criu_msg thing -- instead, we have
explicit request (with per-type args) and explicit responce
(yet again -- with per-type args).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The most of fields are to be changed to "optional", because they are
optional in fact.
Signed-off-by: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
If criu is built from git repo print git commit id, convenient for debug.
For example
| $ ./criu -V
| Version: 0.7
| GitID: 7985251
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Defining it as static char is a bad idea especially
if it get included and never used -- we will get
"unused" variable error.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
-vv...v must increase logging level on a number of the 'v' symbols.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
