A few of our functions use buffer and string functions.
All these functions require that a string contains '\0' at the end.
Before this patch we didn't guarantee that.
I've seen segmentation fault in parse_pid_stat_small.
v2: simplify code
v3: remove assignment, because it's redundant and a size of object file
become bigger.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This test is very basic :( Need more work on it.
One note about --close arg to crtools -- bash leaves all
fds open when laucnhing progams, and for restore this is
critical, as one of them can be busy. Iterating over all
the possibel fds and closing them is "do not want" thing.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
What it does is uses the tcp repair engine from the kernel.
On dump the connection is locked with netfilter, socket is put
in the repair state and then its internals are dumped.
On restore we create a socket, put it into repair, dress it up
and then unlock all the connections at the very end.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
When dump finished with error we should unlock all locked
previously connections.
When restoring we should collect connctions and unlock them
all at the end.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Between dump and restore of a tcp conn we have to keep the connection
blocked, since the socket doesn't exists in the kernel at this time
and any packet from peer will result in RST. Thus, add the -j DROP rule
for every connection we're about to repair.
Later, when we support containers, this will be extended to stop the
whole networking in a CT instead of cherry-peeking connections.
It does system("iptables ...") for this, but I'd prefer using the
libnetfilter-devel sometime in the future.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
First of all -- to make crtools dump/restore established tcp sockets
you have to specify the --tcp-established options. By doing so you
inform crtools that
a) you know, that after dump there will be a netfilter rules blocking
the dumped connections
b) you guarantee, that before restore this netfilter block is still
there
What else this patch does is simple -- collects establised sockets and
calls the dump/restore tcp function (now empty) where appropriate.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Funny, but after this git thinks, that I've renamed the sockets.c
file into sk-unix.c one and fixed it a little bit %)
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Collect all unix sockets in a list while dumping to check
whether we've missed something early (at the restore time
it can be already late for roll-back).
Plus, fix the checks for external stream sockets.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This is common, that opened fd fix its fowner and flags. Make
a cuntion for this. Those that obtain fd with open() don't need
to restore flags though.
A thought -- do we need yet another abstraction between fdinfo and
type-d files?
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The conn job misses fowner restoratio. Other places are ok, but toss
the code for easier next patching.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The kernel patch titled
c/r: prctl: Simplify PR_SET_MM on mm::code/data assignment
(which now in linux-next) allows us to setup code/data addresses
without requirement of underlied VMA. So revert commit
090513d5fd and make code
more simplier
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Kernel 3.4-rc4 has two formats for stack
"[stack]" and "[stack:%d]" (for threads)
so adopt our parsing routine for both.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
To reflect the change in kernel v3.4-rc4
update PR_GET_TID_ADDR and rename it to
PR_GET_TID_ADDRESS as it named in kernel.
[xemul: this fixes futex test broken with 3.4 rebase]
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Some of them (FC12 I debug on) doesn't have fown_ex stuff in their
libc. Add the missing declarations.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Since 3.4-rc the seize-devel flag is removed, the stop event
is renamed (great) and the way si_code should be parsed has
been fixed.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
printf() has standard flag for adding "0x" prefix before hexadecimal integer.
MOD='[-+]\?[0-9]*.\?[0-9]*[lL]*'
git grep -l "0x%${MOD}x" | xargs -n1 sed -e "s/0x%\(${MOD}\)x/%#\1x/g" -i
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Easier to read.
[ xemul: There's a silent change in how sk buffer is read in -- before
the patch there was a static buffer for data, now this thing is
xrealloc-ed ]
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This allows to have more detailed control over files
generated and might be extended in future.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Should be -fpie (actually it's not a problem
at moment since asm files have simple code
and work even without -fpie passed, but better
to fix it anyaway).
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
In case if dgram socket peer is not connected back
we can try to resolve peer by name.
For security reason this happens only if '-x' option
is passed at checkpoint and restore time.
In particular this is needed for programs which do
use dgram socket to send messages to /dev/log.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
At early days we've been using only a few syscalls
which together with debug compiler options always
produce relative addresses for memory variables used
in parasite and restorer blobs. Thus it came in unnoticed
that there is something worng with syscalls declarations
we use.
Basically all our syscalls are just a wrappers over inline
assembly code in form of
static long syscall2(int nr, long arg0, long arg1)
{
long ret;
asm volatile(
"movl %1, %%eax \t\n"
"movq %2, %%rdi \t\n"
"movq %3, %%rsi \t\n"
"syscall \t\n"
"movq %%rax, %0 \t\n"
: "=r"(ret)
: "g" ((int)nr), "g" (arg0), "g" (arg1)
: "rax", "rdi", "rsi", "memory");
return ret;
}
so every argument treated to be plain long (even if the call
sematics implies it's a memory address passed but not some
integer direct value) and transferred via general purpose
register.
As being mentioned it caused no problems when debug options
specified at compile time, the compiler do not tries to optimize
addressing but generates code which always compute them.
The situation is changed if one is building crtools with
optimization enabled -- the compiler finds that arguments
are rather plain long numbers and might pass direct addresses
of variables, instead of generating relative addresses
(because function declarations have no pointers and 'g' in cope
with 'mov' is used, which is of course wrong).
To fix all this -- now syscalls declarations are generated from
syscall.def file and function arguments are passed in conform
with x86-64 ABI.
This shrinks amount of source code needed to declare syscalls
and opens a way to use optimization.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Inline assembly is very convenient if a couple of
instructions is used but when it grows better to
move it out of wrapper C code and write in plain
assembly, after all we need a very precise control
in bootstrap code.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Since the blob files are generated a different way
in compare with plain compiling we use for regular
*.c files -- add own Makefile.pie for this target.
This increases readability of general Makefile
and Makefile.pie itself.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Instead of generating offsets from early compiled
object files (one day the offsets obtained from
there might be changed during linkage stage) better
to get them from a final stage where all object
files involved are linked into complete binary blob.
That happened that at early stage we indeed were using
only single file per parasite and restorer but at present
there a couple of file involved (and will be more in
future) so we need a safe approach.
Also note the symbols being exported are prefixed as
"__export_". This is easier approach for now. Putting
such symbols into separate section requires a way
more efforts to handle.
The main reason of having two files (Elf object
and binary blob) is to get 1:1 mapping between
symbols definition and their position in binary
target.
The exported symbols name addresses are obtained
from object file and used as offsets in binary
target.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Build one "section for all" only. This reflects
what we really do runtime with generated parasite
and restorer blobs.
Signle section is named as ".crblob".
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Don't re-read fdinfo image 4 times on restore, just use those collected
on me pstree_entry instance.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
