Add "get_rseq_conf" feature corresponding to the
ptrace(PTRACE_GET_RSEQ_CONFIGURATION) support.
Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
CRIU has a few places where it creates unix sockets and their names have to be
unique for each criu run.
Fixes: #1798
Signed-off-by: Andrei Vagin <avagin@google.com>
This is the workaround for #1429.
The parasite code contains instructions that trigger SIGTRAP to stop at
certain points. In such cases, the kernel sends a force SIGTRAP that
can't be ignore and if it is blocked, the kernel resets its signal
handler to a default one and unblocks it. It means that if we want to
save the origin signal handle
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Arch-dependend way to restore extended registers set.
Use it straight-away to restore per-thread registers.
Signed-off-by: Dmitry Safonov <dima@arista.com>
Extended registers set for task is restored with rt_sigreturn() through
prepared sigframe. For threads it's currently lost.
Preserve it inside thread context to restore on thread curing.
Signed-off-by: Dmitry Safonov <dima@arista.com>
With pseudo-random garbage, the seed is printed with pr_err().
get_task_regs() is called during seizing the task and also for each
thread.
At this moment only for x86.
Signed-off-by: Dmitry Safonov <dima@arista.com>
To minimize things done in parasite, PTRACE_GET_THREAD_AREA can be
used to get remote tls. That also removes an additional compat stack
(de)allocation in the parasite (also asm-coded syscall).
In order to use PTRACE_GET_THREAD_AREA, the dumpee should be stopped.
So, let's move this from criu to compel to non-seized state and put tls
into thread info on x86.
Signed-off-by: Dmitry Safonov <dima@arista.com>
Some kernels have W^X mitigation, which means they won't execute memory
blocks if that memory block is also writable or ever was writable. This
patch enables CRIU to run on such kernels.
1. Align .data section to a page.
2. mmap a memory block for parasite as RX.
3. mprotect everything after .text as RW.
Signed-off-by: Michał Cłapiński <mclapinski@google.com>
Previously, the GOT table was using the same memory location as the
args region, leading to difficult to debug memory corruption bugs.
We allocate the GOT table between the parasite blob and the args region.
The reason this is a good placement is:
1) Putting it after the args region is possible but a bit combersome as
the args region has a variable size
2) The cr-restore.c code maps the parasite code without the args region,
as it does not do RPC.
Another option is to rely on the linker to generate a GOT section, but I
failed to do so despite my best attempts.
Signed-off-by: Nicolas Viennot <Nicolas.Viennot@twosigma.com>
Previously, __export_parasite_cmd was located in parasite-head.S, and
__export_parasite_args located exactly at the end of the parasite blob.
This is not ideal for various reasons:
1) These two variables work together. It would be preferrable to have
them in the same location
2) This prevent us from allocating another section betweeen the parasite
blob and the args area. We'll need this to allocate a GOT table
This commit changes the allocation of these symbols from assembly/linker
script to a C file.
Moreover, the assembly entry points that invoke parasite_service()
prepares arguments with hand crafted assembly. This is unecessary.
This commit rewrite this logic with regular C code.
Note: if it wasn't for the x86 compat mode, we could remove all
parasite-head.S files and directly jump to parasite_service() via
ptrace. An int3 architecture specific equivalent could be called at the
end of parasite_service() with an inline asm statement.
Signed-off-by: Nicolas Viennot <Nicolas.Viennot@twosigma.com>
It removes the potential confusion when it comes to virtual address vs
offsets. Further, doing so makes naming more consistent with the rest of
the parasite_blob_desc struct.
Signed-off-by: Nicolas Viennot <Nicolas.Viennot@twosigma.com>
compel_relocs_apply() was taking arguments mostly from the struct
parasite_blob_desc. Instead of passing all the arguments, we pass a
pointer to the struct itself.
This makes the code safer, as cr-restore.c calls compel_relocs_apply().
It previously needed to poke into what can be considered private
variables of the restorer-pie.h file.
To allow the parasite_blob_desc struct to be populated without a
parasite_ctl struct, we expand the compel API to export a
parasite_setup_c_header_desc() in the generated pie.h.
Signed-off-by: Nicolas Viennot <Nicolas.Viennot@twosigma.com>
The file only includes other headers (which may be not needed).
If we aim for one-include-for-compel, we could instead paste all
subheaders into "compel.h".
Rather, I think it's worth to migrate to more fine-grained compel
headers than follow the strategy 'one header to rule them all'.
Further, the header creates problems for cross-compilation: it's
included in files, those are used by host-compel. Which rightfully
confuses compiler/linker as host's definitions for fpu regs/other
platform details get drained into host's compel.
Signed-off-by: Dmitry Safonov <dima@arista.com>
All those compel functions can fail by various reasons.
It may be status of the system, interruption by user or anything else.
It's really desired to handle as many PIE related errors as possible
otherwise it's hard to analyze statuses of parasite/restorer
and the C/R process.
At least warning for logs should be produced or even C/R stopped.
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
There are a few places where spaces have been used instead of tabs for
indentation. This patch converts the spaces to tabs for consistency
with the rest of the code base.
Signed-off-by: Radostin Stoyanov <rstoyanov1@gmail.com>
with Android P's Clang versoin: 6.0.2, and Android NDK's Clang version 8.0.2
Clang will report below error:
criu/compel/include/uapi/compel/sigframe-common.h:55:34: error: expected member name or ';' after declaration specifiers
int __unused[32 - (sizeof (k_rtsigset_t) / sizeof (int))];
~~~ ^
it takes __unused as an attribute, not a varible, chang to _unused, pass compile.
Cc: Chen Hu <hu1.chen@intel.com>
Signed-off-by: Zhang Ning <ning.a.zhang@intel.com>
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
We need to know what are stack pointers of every thread to ensure that the
current stack page will not be treated as lazy.
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Alice Frosi <alice@linux.vnet.ibm.com>
Reviewed-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Will need them to mask some of the features from
command line options.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
On fedora rawhide seccomp_metadata for some
reason is not defined (while in kernel it introduced
together with PTRACE_SECCOMP_GET_METADATA). So
lets do a trick for a while -- define own alias.
Once system headers get settled down we might find
more suitable solution. Because it's a part of kernel
API we're on the safe side.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
We will use it to figure out if filter log target is used.
Metadata associated with seccomp filter is relatively new
feature which allows userspace to get and set it back.
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
For architectures like aarch64/ppc64 it's needed to propagate the size
of page inside PIEs. For the parasite page size will be defined during
seizing, and for restorer during early initialization.
Afterward we can use PAGE_SIZE in PIEs like we did before.
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Ugh, I've spent 25 mins at 4 A.M. to figure out why the tests are failing.
And the reason is stupied me, who defined a new flag after 0x8
as 0x16, not as 0x10. Simplify those definitions for such simple-minded
living creatures like Dima.
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
On Skylake processors and kernel older than v4.14
ptrace(PTRACE_GETREGSET, pid, NT_X86_XSTATE, iov)
may return not full xstate, ommiting FP part (that is XFEATURE_MASK_FP).
There is a patch which describes this bug:
https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1318800.html
Anyway, it's fixed in v4.14 kernel by (what we believe with Andrey) this:
https://patchwork.kernel.org/patch/9567939/
As we still support kernels from v3.10 and newer, we need to have a
workaround for this kernel bug on Skylake CPUs.
Big thanks to Shlomi for the reports, the effort and for providing an
Amazon VM to test this. I wish more bug reporters were like you.
Reported-by: Shlomi Matichin <shlomi@binaris.com>
Provided-test-env: Shlomi Matichin <shlomi@binaris.com>
Investigated-with: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
get_task_regs() needs to know if it needs to use workaround
for a Skylake ptrace() bug. The next patch will introduce a
new flag for that.
I also thought about making 3 versions of get_task_regs() and
adding them to ictx->get_task_regs() depending on the flags..
But get_task_regs() is a private function and infect_ctx is
a uapi.. So, let's just pass context flags to get_task_regs().
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
As we anyway define save_regs_t for other purposes,
use it in the function declaration.
To unify infect_ctx style, add make_sigframe_t.
Mere cleanup.
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Some get_status() methods may allocate data, because
not all of the fields in /proc/[pid]/status file
have the fixed size. For example, NSpid, which
size may vary.
Introduce new method free_status() in counterweight
for such type get_status() methods. it will be called
in case of we go to try_again and need to free allocated
data.
Also, introduce data parameter for a use in the future.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
The goal of this function is to compare everything except caps,
but caps size is took to compare. It's wrong, there must be
used offsetof(struct proc_status_creds, cap_inh) instead.
Also, sigpnd may be different too.
v3: Move excluding sigpnd from comparation in this patch (was in another patch).
Reorder fields in seize_task_status().
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
This naming is left from the first compatible kernel patches.
At that time to return to 32-bit task rt_sigreturn was used with
a special flag.
Now it's not true anymore, the naming doesn't relate.
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
These helpers are valuable and can be used outside.
Signed-off-by: Stanislav Kinsburskiy <skinsbursky@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
When infecting victim we construct sigframe to
be able to self-rectore it in case if something
goes wrong. But in case is a targer been using
alternative stack for signal handling it will
be missed in sigframe since we don't fetch it.
Thus add fetching sas on infection stage and
put it into signal frame early.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
CID 73371 (#1 of 1): Big parameter passed by value (PASS_BY_VALUE)
pass_by_value: Passing parameter regs of type user_regs_struct_t
(size 224 bytes) by value.
Suggesting to do this until compel is released and API is cut in stone.
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Found by Coverity error:
> CID 172193 (#1 of 1): Bad bit shift operation (BAD_SHIFT)
> 1. large_shift: In expression 1 << sig % 64, left shifting
> by more than 31 bits has undefined behavior. The shift amount,
> sig % 64, is as much as 63.
That is:
1. yes, UB
2. while adding a signal to mask, this has flushed all other
signals from mask.
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
This function works like printf, and it helps the compiler
to know that, so it can check whether arguments fit the
format string.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
These are part of compel UAPI so should be prefixed with COMPEL_
in order to not pollute the namespace. While at it, move from
set of defines to an enum, which looks a bit cleaner.
Also, kill LOG_UNDEF as it's not used anywhere.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Those macros look twice as long as they should be on my 80-columns
terminal. As there is nothing here to justify such width, go ahead
and remove the extra tabs, keeping the code within 80 cols.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
It's now obsoleted by compel library.
Maybe-TODO: Add compel tool exec action?
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
