There were multiple copy of the same code spread over the different
architectures handling the vDSO.
This patch is merging the duplicated code in arch/*/vdso-pie.c and
arch/*/include/asm/vdso.h in the common files and let only the architecture
specific part in the arch/*/* files.
The file are now organized this way:
include/asm-generic/vdso.h
contains basic definition which could be overwritten by
architectures.
arch/*/include/asm/vdso.h
contains per architecture definitions.
It may includes include/asm-generic/vdso.h
pie/util-vdso.c
include/util-vdso.h
These files contains code and definitions common to both criu and
the parasite code.
The file include/util-vdso.h includes arch/*/include/asm/vdso.h.
pie/parsite-vdso.c
include/parasite-vdso.h
contains code and definition specific to the parasite code handling
the vDSO.
The file include/parasite-vdso.h includes include/util-vdso.h.
arch/*/vdso-pie.c
contains the architecture specific code installing the vDSO
trampoline.
vdso.c
include/vdso.h
contains code and definition specific to the criu code handling the
vDSO.
The file include/vdso.h includes include/util-vdso.h.
CC: Christopher Covington <cov@codeaurora.org>
CC: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Acked-by: Cyrill Gorcunov <gorcunov@gmail.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>
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>
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>
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>
This patch moves the enum VDSO_SYMBOL_* and macros VDSO_SYMBOL_*_NAME
to the x86 specific header since different architectures export
different symbols from their vDSOs.
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>
In commit 2f5df09da5
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>
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>
Instead of opencoded mark injection provide
a helper for easier grepability.
[xemul: Go ahead and remove the INIT_VDSO_MARK at all]
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
In case if we have created vdso proxy the rt-vdso should
not be dumped because it will be re-created on next restore
anyway. Thus with help of parasite service routine find
the rt-vdso and tear it off from VMAs list.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
In case if we need vdso proxy there is a need
to recognize it somehow on further checkpoint
action. But such vdso won't be recognized by
the kernel and [vdso] mark won't appear in
procfs output. Thus we put own mark on it.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We will need it in parasite code to detect run time vdso area.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
During criu startup we need to fill symbol table of own
run-time vdso provided by the kernel. We will need this
data for vdso proxy.
Because this functions are not used in restorer code,
we move them out of PIE (since PIE code must remain
as small as possible).
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It's quite minimal at moment and provides only two helpers
- vdso_redirect_calls, to patch vdso area redirectling
calls to some new place.
- vdso_fill_symtable, to parse vma area as vdso library
and fill symbols table with offsets and names.
Because these routines will be needed in both regular criu
code and restorer code -- we compile it in pie format.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
