The task_entries is a small structure used to coordinate the
processes restore stages. Currentl we allocate one page for
it and handle one separately. No need in this complexity, actually.
The rst_mem engine is already capable to controll this small object.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Needed for future user namespace support. Capabilities will have to be
dumped from the parasite, ie from inside the namespace since there is no
obvious way to 'translate' capabilities from the global namespace (unlike
with uids and gids, where the id mappings can be used for translation).
[ additional explanation from Andrew Vagin:
"capabilities" are not translated between namespaces. They can exist
only in one userns, where a process lives. If a process is created in a
new userns, it gets a full set of capabilities in this userns, and
loses all caps in a parent userns.
So if capabilities are not shown in /proc/pid/stat, we have no way to
get it except of using parasite code. ]
Signed-off-by: Sophie Blee-Goldman <ableegoldman@google.com>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This modifies the x86 VDSO code to work on AArch64.
Signed-off-by: Christopher Covington <cov@codeaurora.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Otherwise we might take a look on last vma from previous
cycle not running vdso analisys at all.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
In worst case we might be tryin to proxify vdso zone
when vvar only is remmaped but vdso itself is not yet
(left and right zones shifting). Thus vdso_proxify
will complain that vdso is not yet mapped refusing
to restore.
Thus wait until everything is re-mapped then call
for proxification helper.
Reported: Mr. Jenkins
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
In latest linux-next the vdso zone is placed _after_ vvar
zone so eventually we need to handle any combination of
the following cases
- no vvar zone
- vvar before vdso
- vvar after vdso
Here we address all them.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Since we might have a several vDSO zones lets hide
handling in arch-specific routines.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The implementation is pretty straightforward. When dumping per-thread
misc data with parasite, collect one, then write in thread_core_info.
On restore wait for creds restore and put the value back (some creds
changes drop it to zero).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Otherwise we're meeting somehow corrupted mark and
must abort dumping.
Reported-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
New kernel 3.16 will have old vDSO zone splitted into the two vmas:
one for vdso code itself and second that named vvar for data been
referenced from vdso code.
Because I can't do 'dump' and 'restore' parts of the code separately
(otherwise test would fail) the commit is pretty big one and hard to
read so here is detailed explanation what's going on.
1) When start dumping we detect vvar zone by reading /proc/pid/smap
and looking up for "[vvar]" token. Note the vvar zone is mapped
by a kernel with PF/IO flags so we should not fail here.
Also it's assumed that at least for now kernel won't be changed
much and [vvar] zone always follows the [vdso] zone, otherwise
criu will print error.
2) In previous commits we disabled dumping vvar area contents so
the restorer code never try to read vvar data but still we need
to map vvar zone thus vma entry remains in image.
3) As with previous vdso format we might have 2 cases
a) Dump and restore is happening on same kernel
b) Dump and restore are done on different kernels
To detect which case we have we parse vdso data from image
and find symbols offsets then compare their values with runtime
symbols provided us by a kernel. If they match and (!!!) the
size of vvar zone is the same -- we simply remap both zones
from runtime kernel into the positions dumpee had at checkpoint
time. This is that named "inplace" remap (a).
If this happens the vdso_proxify() routine drops VMA_AREA_REGULAR
from vvar area provided by a caller code and restorer won't try
to handle this vma. It looks somehow strange and probably should
be reworked but for now I left it as is to minimize the patch.
In case of (b) we need to generate a proxy. We do that in same
way as we were before just include vvar zone into proxy and save
vvar proxy address inside vdso mark injected into vdso area. Thus
on subsequent checkpoint we can detect proxy vvar zone and rip
it off the list of vmas to handle.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Because of new vvar area we need to carry the
address of vvar proxy inside the mark. Thus
add members needed and update routines.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Commit d5bb7e9748 started to preserve the dumpable flag across migration by
using prctl to get the value on dump and set it back on restore.
On some situations, the dumpable flag can be set to 2. This happens when it is
not reset (with prctl) after using setuid() or after using execv() on a binary
that has executable but not read permissions, when the fs.suid_dumpable sysctl
is also set to 2. However, it is not possible to set it to 2 using prctl,
which would make criu restore fail.
Fix this by checking for the value before passing it to prctl. In case the
value of the dumpable flag was 2 at the source, check whether it is already 2
at the destination, which is likely to happen if the fs.suid_dumpable sysctl is
also set to 2 where restore is running. In that case, preserve the value,
otherwise reset it to 0 which is the most secure fallback.
Fixes: d5bb7e9748
Tested:
- Using dumpable02 zdtm test after setting fs.suid_dumpable to 2.
# sysctl -w fs.suid_dumpable=2
# test/zdtm.sh ns/static/dumpable02
4: DEBUG: before dump: dumpable=2
4: DEBUG: after restore: dumpable=2
4: PASS
Test: zdtm/live/static/dumpable02, Result: PASS
Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This reverts commit 8870aa1e4f.
Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Otherwise I see on 3.16-rc1 and higher
| [ 100.851730] futex wrote to ns_last_pid when file position was not 0!
| This will not be supported in the future. To silence this
| warning, set kernel.sysctl_writes_strict = -1
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
[ xemul: It's a temporary workaround not to lock the -rc2 release.
Once we have some better solution, this will be rolled back. ]
Signed-off-by: Saied Kazemi <saied@google.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Currently we build vDSO handling code for all archs provided
in the source code having some "common" parts inside pie/vdso.c,
pie/vdso-stub.c, vdso-stub.c and vdso.c. This were more or
less well but in new linux kernels (starting from 3.16 presumably)
the vDSO has been significantly reworked so every architecture
must have own vDSO handling engine (just like the kernel does).
So in this patch we move vDSO code to arch specific and because
aarch64 actually doesn't implement proxification yet due to
kernel restrictions -- we drops it out. When there will be
kernel support we bring it back in proper arch/aarch64
implementation.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Guard vDSO code with CONFIG_VDSO, no need to even build it
on archs which do not support vDSO handling.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Preserve the dumpable flag, which affects whether a core dump will be
generated, but also affects the ownership of the virtual files under
/proc/$pid after restoring a process.
Tested: Restored a process with a criu including this patch and looked
at /proc/$pid to confirm that the virtual files were no longer all owned
by root:root.
zdtm tests pass except for cow01 which seems to be broken.
(see https://bugzilla.openvz.org/show_bug.cgi?id=2967 for details.)
This patch fixes https://bugzilla.openvz.org/show_bug.cgi?id=2968
Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Change-Id: I8c386508448a84368a86666f2d7500b252a78bbf
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This patch splits the file arch/x86/vdso-pie.c into machine-dependent
and machine-independent parts by moving the routines vdso_fill_symtable(),
vdso_proxify(), and vdso_remap() to the file pie/vdso.c.
The ARM version of the routines is moved to the source pie/vdso-stub.c
to provide the vDSO proxy stub implementation for architectures
that don't provide the vDSO.
Signed-off-by: Alexander Kartashov <alekskartashov@parallels.com>
Looks-good-to: Cyrill Gorcunov <gorcunov@openvz.org>
Reviewed-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Supported machine architectures provide TLS stogares of different sizes:
the size of the TLS storage in x86-64 is 24 bytes, ARM --- 4 bytes
and upcoming AArch64 --- 8 bytes. This means every supported architecture
needs a specific type to store the value of the TLS register.
This patch reworks the insterface of the routines arch_get_tls()
and restore_tls() passing them the TLS storage by pointer
rather than by value to simplify the TLS stub for x86.
Signed-off-by: Alexander Kartashov <alekskartashov@parallels.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Reviewed-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The pie.lds.S.in needs two minor changes to work with the gold (/usr/bin/gold)
linker. These changes are compatible with /usr/bin/ld and make linker script
more portable.
The first change is adding a comma before /DISCARD/ so that the grammar
won't be ambiguous. A Otherwise, gold treats it as a part of the assignment
and would generate a syntax error about the "unexpected ':'".
The second change is moving initialization of __export_parasite_args
to inside the SECTIONS command because it references the dot symbol.
Otherwise, gold would generate the error "invalid reference to dot
symbol outside of SECTIONS clause.
Signed-off-by: Saied Kazemi <saied@google.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
To be able to profile CRIU with gprof support we need a special flag
passed to the compiler and linker. But same time we can't build parasite
code with prof support because it'll call for mcount() service routine
for which we don't have any stub yet (and even if we had there are
other tech details involved). Thus PIE code won't be profiled.
To compile with prof support make it as
make DEBUG=1 GMON=1
The idea to run gprof then over criu sources. Once you've it
compiled with the flags mentioned above -- simply run it (test or whatever,
I've been running sh test/zdtm.st static.maps00).
Then run gprof ./criu gmon.out
Note the gmon.out file lays in directory where criu were running, thus
in case of sh test/zdtm.st static.maps00 the output file will be in test/
directory.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
make engine will be reworked to clean up only those
files which were generated with implicit rules. Thus
anything generated in specific way must be cleaned
up explicitly.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Remove space before tab characters.
Found by git grep ' ' (Space, Ctrl-V, Tab in shell).
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Remove whitespace at EOL (found by git grep ' $')
To people using vim, I'd suggest adding the following code to ~/.vimrc:
let c_space_errors = 1
highlight FormatError ctermbg=darkred guibg=darkred
match FormatError /\s\+$\|\ \+\t\|\%80v.\|\ \{8\}/
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Move prctl constants into own header. They are
arch independent.
The x86 specific ARCH_SET_GS should be fetched from <asm/prctl.h>
(instead of defining own ones).
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This limit is not exported by a kernel, so no need
to "explicitly" define it pretending that it's immutable.
Still I kept this name in comment just to give reader
a tip where CR_SCM_MAX_FD came from.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
fcntl data is arch independent, so move it out of include/asm/type.h
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This actually fixes a bug -- memory for shmem info was
not allocated dynamically, thus we were limited in the
amount of shmems to be restored.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
In case if we need to use vdso proxy the memory area
which holds restorer also has a place for vdso proxy
code itself, so on final pass we should not unmap it,
otherwise any call to vdso function will cause sigsegv.
IOW, the memory before final "cleanup" pass of restorer
might look as
+-----------+---------+ +-------------+------+
| bootstrap | rt-vdso | ... | application | vdso |
+-----------+---------+ +-------------+------+
^ |
`-------------------------+
and we have redirected "vdso" code to jump to "rt-vdso".
After final pass the memory must look as
+---------+ +-------------+------+
| rt-vdso | ... | application | vdso |
+---------+ +-------------+------+
^ |
`-------------------------+
I noticed this problem during container migration
testing, the container itself was suspended on 2.6.32
OpenVZ kernel with apache running inside, and any attempt
to connect to apache caused apache to crash.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
In case if we hit error returned from syscall, better
to print error code for easier understanding of the
protblem.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
