On Arm platform, "setMemoryRegion" has extra permission checks.
In virt/kvm/arm/mmu.c: kvm_arch_prepare_memory_region()
....
if (writable && !(vma->vm_flags & VM_WRITE)) {
ret = -EPERM;
break;
}
....
So, for Arm platform, the "flags" for kvm_memory_region is required.
And on x86 platform, the "flags" can be always set as '0'.
Signed-off-by: Bin Lu <bin.lu@arm.com>
COPYBARA_INTEGRATE_REVIEW=https://github.com/google/gvisor/pull/810 from lubinszARM:pr_setregion 8c99b19cfb0c859c6630a1cfff951db65fcf87ac
PiperOrigin-RevId: 277602603
This patch enabled the basic framework for arm64 guest.
Serveral jobs were finished in this patch:
1, ring0.Vectors()
2, switchToUser()
3, basic framwork for Arm64 guest.
Signed-off-by: Bin Lu <bin.lu@arm.com>
Before https://golang.org/cl/173160 syscall.RawSyscall would zero out
the last three register arguments to the system call. That no longer happens.
For system calls that take more than three arguments, use RawSyscall6 to
ensure that we pass zero, not random data, for the additional arguments.
PiperOrigin-RevId: 271062527
enable kvm/testutil to support arm64
The Arm64 user-mode execution stat consists of:
1, X0- X30
2, PC, SP, PSTATE
3, TPIDR_EL0, used for TLS
4, V0-V31: 32 128-bit registers for floating point and simd
5, FPSR
Currently, we first try to achieve goals 1 and 2.
This patch provids basic test utils for goals 1 & 2
Signed-off-by: Bin Lu <bin.lu@arm.com>
The simple test script has gotten out of control. Shard this script into
different pieces and attempt to impose order on overall test structure. This
change helps lay some of the foundations for future improvements.
* The runsc/test directories are moved into just test/.
* The runsc/test/testutil package is split into logical pieces.
* The scripts/ directory contains new top-level targets.
* Each test is now responsible for building targets it requires.
* The install functionality is moved into `runsc` itself for simplicity.
* The existing kokoro run_tests.sh file now just calls all (can be split).
After this change is merged, I will create multiple distinct workflows for
Kokoro, one for each of the scripts currently targeted by `run_tests.sh` today,
which should dramatically reduce the time-to-run for the Kokoro tests, and
provides a better foundation for further improvements to the infrastructure.
PiperOrigin-RevId: 267081397
m.available.Signal() has to be called under m.mu.RLock, otherwise it can
race with machine.Get:
m.Get | m.Put
-------------------------------------
m.mu.Lock() |
Seatching available vcpu|
| m.available.Signal()
m.available.Wait |
PiperOrigin-RevId: 259394051
Now we call FUTEX_WAKE with ^uintptr(0) of waiters, but in this case only one
waiter will be waked up. If we want to wake up all of them, the number of
waiters has to be set to math.MaxInt32.
PiperOrigin-RevId: 258285286
A userspace process (CPL=3) can access an i/o port if the bit corresponding to
the port is set to 0 in the I/O permission bitmap.
Configure the I/O permission bitmap address beyond the last valid byte in the
TSS so access to all i/o ports is blocked.
Signed-off-by: Liu Hua <sdu.liu@huawei.com>
Change-Id: I3df76980c3735491db768f7210e71703f86bb989
PiperOrigin-RevId: 257336518
BounceToKernel will make vCPU quit from guest ring3 to guest ring0, but
vCPUWaiter is not cleared when we unlock the vCPU, when next time this vCPU
enter guest mode ring3, vCPU may enter guest mode with vCPUWaiter bit setted,
this will cause the following BounceToKernel to this vCPU hangs at
waitUntilNot.
Halt may workaroud this issue, because halt process will reset vCPU status into
vCPUUser, and notify all waiter for vCPU state change, but if there is no
exception or syscall in this period, BounceToKernel will hang at waitUntilNot.
PiperOrigin-RevId: 256299660
Right now, if we can't create a stub process, we will see this error:
panic: unable to activate mm: resource temporarily unavailable
It would be better to know the root cause of this "resource temporarily
unavailable".
PiperOrigin-RevId: 255656831
Addresses obvious typos, in the documentation only.
COPYBARA_INTEGRATE_REVIEW=https://github.com/google/gvisor/pull/443 from Pixep:fix/documentation-spelling 4d0688164eafaf0b3010e5f4824b35d1e7176d65
PiperOrigin-RevId: 255477779
The tracee is stopped early during process exit, when registers are still
available, allowing the tracer to see where the exit occurred, whereas the
normal exit notifi? cation is done after the process is finished exiting.
Without this option, dumpAndPanic fails to get registers.
PiperOrigin-RevId: 254852917
Funcion signatures are not validated during compilation. Since
they are not exported, they can change at any time. The guard
ensures that they are verified at least on every version upgrade.
PiperOrigin-RevId: 250733742
Based on the guidelines at
https://opensource.google.com/docs/releasing/authors/.
1. $ rg -l "Google LLC" | xargs sed -i 's/Google LLC.*/The gVisor Authors./'
2. Manual fixup of "Google Inc" references.
3. Add AUTHORS file. Authors may request to be added to this file.
4. Point netstack AUTHORS to gVisor AUTHORS. Drop CONTRIBUTORS.
Fixes#209
PiperOrigin-RevId: 245823212
Change-Id: I64530b24ad021a7d683137459cafc510f5ee1de9
Change the DPL from 0 to 3 for Breakpoint and Overflow,
then user space could trigger Breakpoint and Overflow
as excepected.
Change-Id: Ibead65fb8c98b32b7737f316db93b3a8d9dcd648
PiperOrigin-RevId: 239736648
This is in preparation for improved page cache reclaim, which requires
greater integration between the page cache and page allocator.
PiperOrigin-RevId: 238444706
Change-Id: Id24141b3678d96c7d7dc24baddd9be555bffafe4
- Redefine some memmap.Mappable, platform.File, and platform.Memory
semantics in terms of File reference counts (no functional change).
- Make AddressSpace.MapFile take a platform.File instead of a raw FD,
and replace platform.File.MapInto with platform.File.FD. This allows
kvm.AddressSpace.MapFile to always use platform.File.MapInternal instead
of maintaining its own (redundant) cache of file mappings in the sentry
address space.
PiperOrigin-RevId: 238044504
Change-Id: Ib73a11e4275c0da0126d0194aa6c6017a9cef64f
It is Implemented without the priority inheritance part given
that gVisor defers scheduling decisions to Go runtime and doesn't
have control over it.
PiperOrigin-RevId: 236989545
Change-Id: I714c8ca0798743ecf3167b14ffeb5cd834302560
The globalPool uses a sync.Once mechanism for initialization,
and no cleanup is strictly required. It's not really feasible
to have the platform implement a full creation -> destruction
cycle (due to the way filters are assumed to be installed), so
drop the FIXME.
PiperOrigin-RevId: 236385278
Change-Id: I98ac660ed58cc688d8a07147d16074a3e8181314
- Fix CopyIn/CopyOut/ZeroOut range checks.
- Include the faulting signal number in the panic message.
PiperOrigin-RevId: 233829501
Change-Id: I8959ead12d05dbd4cd63c2b908cddeb2a27eb513
Nothing reads them and they can simply get stale.
Generated with:
$ sed -i "s/licenses(\(.*\)).*/licenses(\1)/" **/BUILD
PiperOrigin-RevId: 231818945
Change-Id: Ibc3f9838546b7e94f13f217060d31f4ada9d4bf0
arch_prctl already verified that the new FS_BASE was canonical, but
Task.Clone did not. Centralize these checks in the arch packages.
Failure to validate could cause an error in PTRACE_SET_REGS when we try
to switch to the app.
PiperOrigin-RevId: 224862398
Change-Id: Iefe63b3f9aa6c4810326b8936e501be3ec407f14
RET_KILL_THREAD doesn't work well for Go because it will
kill only the offending thread and leave the process hanging.
RET_TRAP can be masked out and it's not guaranteed to kill
the process. RET_KILL_PROCESS is available since 4.14.
For older kernel, continue to use RET_TRAP as this is the
best option (likely to kill process, easy to debug).
PiperOrigin-RevId: 222357867
Change-Id: Icc1d7d731274b16c2125b7a1ba4f7883fbdb2cbd
This reduces the number of floating point save/restore cycles required (since
we don't need to restore immediately following the switch, this always happens
in a known context) and allows the kernel hooks to capture state. This lets us
remove calls like "Current()".
PiperOrigin-RevId: 219552844
Change-Id: I7676fa2f6c18b9919718458aa888b832a7db8cab
Use private futexes for performance and to align with other runtime uses.
PiperOrigin-RevId: 219422634
Change-Id: Ief2af5e8302847ea6dc246e8d1ee4d64684ca9dd
Pseudoterminal job control signals are meant to be received and handled by the
sandbox process, but if the ptrace stubs are running in the same process group,
they will receive the signals as well and inject then into the sentry kernel.
This can result in duplicate signals being delivered (often to the wrong
process), or a sentry panic if the ptrace stub is inactive.
This CL makes the ptrace stub run in a new session.
PiperOrigin-RevId: 218536851
Change-Id: Ie593c5687439bbfbf690ada3b2197ea71ed60a0e
This change also adds extensive testing to the p9 package via mocks. The sanity
checks and type checks are moved from the gofer into the core package, where
they can be more easily validated.
PiperOrigin-RevId: 218296768
Change-Id: I4fc3c326e7bf1e0e140a454cbacbcc6fd617ab55
This is a defense-in-depth measure. If the sentry is compromised, this prevents
system call injection to the stubs. There is some complexity with respect to
ptrace and seccomp interactions, so this protection is not really available
for kernel versions < 4.8; this is detected dynamically.
Note that this also solves the vsyscall emulation issue by adding in
appropriate trapping for those system calls. It does mean that a compromised
sentry could theoretically inject these into the stub (ignoring the trap and
resume, thereby allowing execution), but they are harmless.
PiperOrigin-RevId: 216647581
Change-Id: Id06c232cbac1f9489b1803ec97f83097fcba8eb8
runApp.execute -> Task.SendSignal -> sendSignalLocked -> sendSignalTimerLocked
-> pendingSignals.enqueue assumes that it owns the arch.SignalInfo returned
from platform.Context.Switch.
On the other hand, ptrace.context.Switch assumes that it owns the returned
SignalInfo and can safely reuse it on the next call to Switch. The KVM platform
always returns a unique SignalInfo.
This becomes a problem when the returned signal is not immediately delivered,
allowing a future signal in Switch to change the previous pending SignalInfo.
This is noticeable in #38 when external SIGINTs are delivered from the PTY
slave FD. Note that the ptrace stubs are in the same process group as the
sentry, so they are eligible to receive the PTY signals. This should probably
change, but is not the only possible cause of this bug.
Updates #38
Original change by newmanwang <wcs1011@gmail.com>, updated by Michael Pratt
<mpratt@google.com>.
Change-Id: I5383840272309df70a29f67b25e8221f933622cd
PiperOrigin-RevId: 213071072
The old kernel version, such as 4.4, only support 255 vcpus.
While gvisor is ran on these kernels, it could panic because the
vcpu id and vcpu number beyond max_vcpus.
Use ioctl(vmfd, _KVM_CHECK_EXTENSION, _KVM_CAP_MAX_VCPUS) to get max
vcpus number dynamically.
Change-Id: I50dd859a11b1c2cea854a8e27d4bf11a411aa45c
PiperOrigin-RevId: 212929704
We were previously openining the platform device (i.e. /dev/kvm) inside the
platfrom constructor (i.e. kvm.New). This requires that we have RW access to
the platform device when constructing the platform.
However, now that the runsc sandbox process runs as user "nobody", it is not
able to open the platform device.
This CL changes the kvm constructor to take the platform device FD, rather than
opening the device file itself. The device file is opened outside of the
sandbox and passed to the sandbox process.
PiperOrigin-RevId: 212505804
Change-Id: I427e1d9de5eb84c84f19d513356e1bb148a52910
Because the Drop method may be called across vCPUs, it is necessary to protect
the PCID database with a mutex to prevent concurrent modification. The PCID is
assigned prior to entersyscall, so it's safe to block.
PiperOrigin-RevId: 207992864
Change-Id: I8b36d55106981f51e30dcf03e12886330bb79d67
Store the new assigned pcid in p.cache[pt].
Signed-off-by: ShiruRen <renshiru2000@gmail.com>
Change-Id: I4aee4e06559e429fb5e90cb9fe28b36139e3b4b6
PiperOrigin-RevId: 207563833
We have been unnecessarily creating too many savable types implicitly.
PiperOrigin-RevId: 206334201
Change-Id: Idc5a3a14bfb7ee125c4f2bb2b1c53164e46f29a8
Per the doc, usage must be kept maximally merged. Beyond that, it is simply a
good idea to keep fragmentation in usage to a minimum.
The glibc malloc allocator allocates one page at a time, potentially causing
lots of fragmentation. However, those pages are likely to have the same number
of references, often making it possible to merge ranges.
PiperOrigin-RevId: 204960339
Change-Id: I03a050cf771c29a4f05b36eaf75b1a09c9465e14
If usageSet is heavily fragmented, findUnallocatedRange and findReclaimable
can spend excessive cycles linearly scanning the set for unallocated/free
pages.
Improve common cases by beginning the scan only at the first page that could
possibly contain an unallocated/free page. This metadata only guarantees that
there is no lower unallocated/free page, but a scan may still be required
(especially for multi-page allocations).
That said, this heuristic can still provide significant performance
improvements for certain applications.
PiperOrigin-RevId: 204841833
Change-Id: Ic41ad33bf9537ecd673a6f5852ab353bf63ea1e6
If the child stubs are killed by any unmaskable signal (e.g. SIGKILL), then
the parent process will similarly be killed, resulting in the death of all
other stubs.
The effect of this is that if the OOM killer selects and kills a stub, the
effect is the same as though the OOM killer selected and killed the sentry.
PiperOrigin-RevId: 202219984
Change-Id: I0b638ce7e59e0a0f4d5cde12a7d05242673049d7
Instead, CPUs will be created dynamically. We also allow a relatively
efficient mechanism for stealing and notifying when a vCPU becomes
available via unlock.
Since the number of vCPUs is no longer fixed at machine creation time,
we make the dirtySet packing more efficient. This has the pleasant side
effect of cutting out the unsafe address space code.
PiperOrigin-RevId: 201266691
Change-Id: I275c73525a4f38e3714b9ac0fd88731c26adfe66
There are circumstances under which the redpill call will not generate
the appropriate action and notification. Replace this call with an
explicit notification, which is guaranteed to transition as well as
perform the futex wake.
PiperOrigin-RevId: 200726934
Change-Id: Ie19e008a6007692dd7335a31a8b59f0af6e54aaa
In order to minimize the likelihood of exit during page table
modifications, make the full set of page table functions split-safe.
This is not strictly necessary (and you may still incur splits due to
allocations from the allocator pool) but should make retries a very rare
occurance.
PiperOrigin-RevId: 200146688
Change-Id: I8fa36aa16b807beda2f0b057be60038258e8d597
Because of the KVM shadow page table implementation, modifications made
to guest page tables from host mode may not be syncronized correctly,
resulting in undefined behavior. This is a KVM bug: page table pages
should also be tracked for host modifications and resynced appropriately
(e.g. the guest could "DMA" into a page table page in theory).
However, since we can't rely on this being fixed everywhere, workaround
the issue by forcing page table modifications to be in guest mode. This
will generally be the case anyways, but now if an exit occurs during
modifications, we will re-enter and perform the modifications again.
PiperOrigin-RevId: 199587895
Change-Id: I83c20b4cf2a9f9fa56f59f34939601dd34538fb0
Instead of associating a single PCID with each set of page tables (which
will reach the maximum quickly), allow a dynamic pool for each vCPU.
This is the same way that Linux operates. We also split management of
PCIDs out of the page tables themselves for simplicity.
PiperOrigin-RevId: 199585631
Change-Id: I42f3486ada3cb2a26f623c65ac279b473ae63201
In order to prevent possible garbage collection and reuse of page table
pages prior to invalidation, introduce a former allocator abstraction
that can ensure entries are held during a single traversal. This also
cleans up the abstraction and splits it out of the machine itself.
PiperOrigin-RevId: 199581636
Change-Id: I2257d5d7ffd9c36f9b7ecd42f769261baeaf115c
This is necessary to prevent races with invalidation. It is currently
possible that page tables are garbage collected while paging caches
refer to them. We must ensure that pages are held until caches can be
invalidated. This is not achieved by this goal alone, but moving locking
to outside the page tables themselves is a requisite.
PiperOrigin-RevId: 198920784
Change-Id: I66fffecd49cb14aa2e676a84a68cabfc0c8b3e9a
Previously, the vCPU FS was always correct because it relied on the
reset coming out of the switch. When that doesn't occur, for example,
using bluepill directly, the FS value can be incorrect leading to
strange corruption.
This change is necessary for a subsequent change that enforces guest
mode for page table modifications, and it may reduce test flakiness.
(The problematic path may occur in tests, but does not occur in the
actual platform.)
PiperOrigin-RevId: 198648137
Change-Id: I513910a973dd8666c9a1d18cf78990964d6a644d
This is a refactor of ring0 and ring0/pagetables that changes from
individual arguments to opts structures. This should involve no
functional changes, but sets the stage for subsequent changes.
PiperOrigin-RevId: 198627556
Change-Id: Id4460340f6a73f0c793cd879324398139cd58ae9
Especially in situations with small numbers of vCPUs, the existing
system resulted in excessive thrashing. Now, execution contexts
co-ordinate as smoothly as they can to share a small number of cores.
PiperOrigin-RevId: 197483323
Change-Id: I0afc0c5363ea9386994355baf3904bf5fe08c56c
gVisor bot
Andrei Vagin
lubinszARM
Michael Pratt
Bin Lu
Kevin Krakauer
Adin Scannell
Haibo Xu
Liu Hua
Yong He
Jamie Liu
Fabricio Voznika
Nicolas Lacasse
Ruidong Cao
Ian Gudger
newmanwang
Chenggang
ShiruRen
Zhaozhong Ni