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path: root/pkg/sentry/kernel/kernel.go
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2020-04-24Move hostfs mount to Kernel struct.Dean Deng
This is needed to set up host fds passed through a Unix socket. Note that the host package depends on kernel, so we cannot set up the hostfs mount directly in Kernel.Init as we do for sockfs and pipefs. Also, adjust sockfs to make its setup look more like hostfs's and pipefs's. PiperOrigin-RevId: 308274053
2020-04-16Implement pipe(2) and pipe2(2) for VFS2.Jamie Liu
Updates #1035 PiperOrigin-RevId: 306968644
2020-04-06Port timerfd to VFS2.Nicolas Lacasse
PiperOrigin-RevId: 305067208
2020-04-04Record VFS2 sockets in global socket map.Dean Deng
Updates #1476, #1478, #1484, #1485. PiperOrigin-RevId: 304845354
2020-04-03Refactor software GSO code.Bhasker Hariharan
Software GSO implementation currently has a complicated code path with implicit assumptions that all packets to WritePackets carry same Data and it does this to avoid allocations on the path etc. But this makes it hard to reuse the WritePackets API. This change breaks all such assumptions by introducing a new Vectorised View API ReadToVV which can be used to cleanly split a VV into multiple independent VVs. Further this change also makes packet buffers linkable to form an intrusive list. This allows us to get rid of the array of packet buffers that are passed in the WritePackets API call and replace it with a list of packet buffers. While this code does introduce some more allocations in the benchmarks it doesn't cause any degradation. Updates #231 PiperOrigin-RevId: 304731742
2020-03-31Add socket filesystem and global disconnected socket mount for VFS2.Dean Deng
A socket mount where anonymous sockets will reside is added to the VirtualFilesystem. Socketfs is built on top of kernfs. Updates #1476, #1478, #1484, #1485. PiperOrigin-RevId: 304095251
2020-03-14Plumb VFS2 imported fds into virtual filesystem.Dean Deng
- When setting up the virtual filesystem, mount a host.filesystem to contain all files that need to be imported. - Make read/preadv syscalls to the host in cases where preadv2 may not be supported yet (likewise for writing). - Make save/restore functions in kernel/kernel.go return early if vfs2 is enabled. PiperOrigin-RevId: 300922353
2020-02-28Hide /dev/net/tun when using hostinet.Ting-Yu Wang
/dev/net/tun does not currently work with hostinet. This has caused some program starts failing because it thinks the feature exists. PiperOrigin-RevId: 297876196
2020-02-25Add option to skip stuck tasks waiting for address spaceFabricio Voznika
PiperOrigin-RevId: 297192390
2020-02-20Initial network namespace support.gVisor bot
TCP/IP will work with netstack networking. hostinet doesn't work, and sockets will have the same behavior as it is now. Before the userspace is able to create device, the default loopback device can be used to test. /proc/net and /sys/net will still be connected to the root network stack; this is the same behavior now. Issue #1833 PiperOrigin-RevId: 296309389
2020-02-14Synchronize signalling with S/RgVisor bot
This is to fix a data race between sending an external signal to a ThreadGroup and kernel saving state for S/R. PiperOrigin-RevId: 295244281
2020-02-14Inline vfs.VirtualFilesystem in Kernel structgVisor bot
This saves one pointer dereference per VFS access. Updates #1623 PiperOrigin-RevId: 295216176
2020-02-14Plumb VFS2 inside the SentrygVisor bot
- Added fsbridge package with interface that can be used to open and read from VFS1 and VFS2 files. - Converted ELF loader to use fsbridge - Added VFS2 types to FSContext - Added vfs.MountNamespace to ThreadGroup Updates #1623 PiperOrigin-RevId: 295183950
2020-02-05Add notes to relevant tests.Adin Scannell
These were out-of-band notes that can help provide additional context and simplify automated imports. PiperOrigin-RevId: 293525915
2020-01-28Add vfs.FileDescription to FD tableFabricio Voznika
FD table now holds both VFS1 and VFS2 types and uses the correct one based on what's set. Parts of this CL are just initial changes (e.g. sys_read.go, runsc/main.go) to serve as a template for the remaining changes. Updates #1487 Updates #1623 PiperOrigin-RevId: 292023223
2020-01-27Update package locations.Adin Scannell
Because the abi will depend on the core types for marshalling (usermem, context, safemem, safecopy), these need to be flattened from the sentry directory. These packages contain no sentry-specific details. PiperOrigin-RevId: 291811289
2020-01-09New sync package.Ian Gudger
* Rename syncutil to sync. * Add aliases to sync types. * Replace existing usage of standard library sync package. This will make it easier to swap out synchronization primitives. For example, this will allow us to use primitives from github.com/sasha-s/go-deadlock to check for lock ordering violations. Updates #1472 PiperOrigin-RevId: 289033387
2019-12-26Initial procfs implementation in VFSv2Fabricio Voznika
Updates #1195 PiperOrigin-RevId: 287227722
2019-12-06Add runtime tracing.Adin Scannell
This adds meaningful annotations to the trace generated by the runtime/trace package. PiperOrigin-RevId: 284290115
2019-10-31Add context to state.Adin Scannell
PiperOrigin-RevId: 277840416
2019-10-29Disallow execveat on interpreter scripts with fd opened with O_CLOEXEC.Dean Deng
When an interpreter script is opened with O_CLOEXEC and the resulting fd is passed into execveat, an ENOENT error should occur (the script would otherwise be inaccessible to the interpreter). This matches the actual behavior of Linux's execveat. PiperOrigin-RevId: 277306680
2019-10-25Aggregate arguments for loading executables into a single struct.Dean Deng
This change simplifies the function signatures of functions related to loading executables, such as LoadTaskImage, Load, loadBinary. PiperOrigin-RevId: 276821187
2019-10-24Handle AT_SYMLINK_NOFOLLOW flag for execveat.Dean Deng
PiperOrigin-RevId: 276441249
2019-10-01Disable cpuClockTicker when app is idleMichael Pratt
Kernel.cpuClockTicker increments kernel.cpuClock, which tasks use as a clock to track their CPU usage. This improves latency in the syscall path by avoid expensive monotonic clock calls on every syscall entry/exit. However, this timer fires every 10ms. Thus, when all tasks are idle (i.e., blocked or stopped), this forces a sentry wakeup every 10ms, when we may otherwise be able to sleep until the next app-relevant event. These wakeups cause the sentry to utilize approximately 2% CPU when the application is otherwise idle. Updates to clock are not strictly necessary when the app is idle, as there are no readers of cpuClock. This commit reduces idle CPU by disabling the timer when tasks are completely idle, and computing its effects at the next wakeup. Rather than disabling the timer as soon as the app goes idle, we wait until the next tick, which provides a window for short sleeps to sleep and wakeup without doing the (relatively) expensive work of disabling and enabling the timer. PiperOrigin-RevId: 272265822
2019-08-08netstack: Don't start endpoint goroutines too soon on restore.Rahat Mahmood
Endpoint protocol goroutines were previously started as part of loading the endpoint. This is potentially too soon, as resources used by these goroutine may not have been loaded. Protocol goroutines may perform meaningful work as soon as they're started (ex: incoming connect) which can cause them to indirectly access resources that haven't been loaded yet. This CL defers resuming all protocol goroutines until the end of restore. PiperOrigin-RevId: 262409429
2019-08-02Remove kernel.mounts.Nicolas Lacasse
We can get the mount namespace from the CreateProcessArgs in all cases where we need it. This also gets rid of kernel.Destroy method, since the only thing it was doing was DecRefing the mounts. Removing the need to call kernel.SetRootMountNamespace also allowed for some more simplifications in the container fs setup code. PiperOrigin-RevId: 261357060
2019-07-31Initialize kernel.unimplementedSyscallEmitter with a sync.Once.Nicolas Lacasse
This is initialized lazily on the first unimplemented syscall. Without the sync.Once, this is racy. PiperOrigin-RevId: 260971758
2019-07-30Add feature to launch Sentry from an open host FD.Zach Koopmans
Adds feature to launch from an open host FD instead of a binary_path. The FD should point to a valid executable and most likely be statically compiled. If the executable is not statically compiled, the loader will search along the interpreter paths, which must be able to be resolved in the Sandbox's file system or start will fail. PiperOrigin-RevId: 260756825
2019-07-29Rate limit the unimplemented syscall event handler.Nicolas Lacasse
This introduces two new types of Emitters: 1. MultiEmitter, which will forward events to other registered Emitters, and 2. RateLimitedEmitter, which will forward events to a wrapped Emitter, subject to given rate limits. The methods in the eventchannel package itself act like a multiEmitter, but is not actually an Emitter. Now we have a DefaultEmitter, and the methods in eventchannel simply forward calls to the DefaultEmitter. The unimplemented syscall handler now uses a RateLimetedEmitter that wraps the DefaultEmitter. PiperOrigin-RevId: 260612770
2019-07-26Merge pull request #452 from zhangningdlut:chris_test_pidnsgVisor bot
PiperOrigin-RevId: 260220279
2019-07-24Use different pidns among different containerschris.zn
The different containers in a sandbox used only one pid namespace before. This results in that a container can see the processes in another container in the same sandbox. This patch use different pid namespace for different containers. Signed-off-by: chris.zn <chris.zn@antfin.com>
2019-07-02Remove map from fd_map, change to fd_table.Adin Scannell
This renames FDMap to FDTable and drops the kernel.FD type, which had an entire package to itself and didn't serve much use (it was freely cast between types, and served as more of an annoyance than providing any protection.) Based on BenchmarkFDLookupAndDecRef-12, we can expect 5-10 ns per lookup operation, and 10-15 ns per concurrent lookup operation of savings. This also fixes two tangential usage issues with the FDMap. Namely, non-atomic use of NewFDFrom and associated calls to Remove (that are both racy and fail to drop the reference on the underlying file.) PiperOrigin-RevId: 256285890
2019-06-27Fix various spelling issues in the documentationMichael Pratt
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
2019-06-19Add MountNamespace to task.Nicolas Lacasse
This allows tasks to have distinct mount namespace, instead of all sharing the kernel's root mount namespace. Currently, the only way for a task to get a different mount namespace than the kernel's root is by explicitly setting a different MountNamespace in CreateProcessArgs, and nothing does this (yet). In a follow-up CL, we will set CreateProcessArgs.MountNamespace when creating a new container inside runsc. Note that "MountNamespace" is a poor term for this thing. It's more like a distinct VFS tree. When we get around to adding real mount namespaces, this will need a better naem. PiperOrigin-RevId: 254009310
2019-06-13Update canonical repository.Adin Scannell
This can be merged after: https://github.com/google/gvisor-website/pull/77 or https://github.com/google/gvisor-website/pull/78 PiperOrigin-RevId: 253132620
2019-06-10Store more information in the kernel socket table.Rahat Mahmood
Store enough information in the kernel socket table to distinguish between different types of sockets. Previously we were only storing the socket family, but this isn't enough to classify sockets. For example, TCPv4 and UDPv4 sockets are both AF_INET, and ICMP sockets are SOCK_DGRAM sockets with a particular protocol. Instead of creating more sub-tables, flatten the socket table and provide a filtering mechanism based on the socket entry. Also generate and store a socket entry index ("sl" in linux) which allows us to output entries in a stable order from procfs. PiperOrigin-RevId: 252495895
2019-05-10Add pgalloc.DelayedEvictionManual.Jamie Liu
PiperOrigin-RevId: 247667272 Change-Id: I16b04e11bb93f50b7e05e888992303f730e4a877
2019-04-30Implement async MemoryFile eviction, and use it in CachingInodeOperations.Jamie Liu
This feature allows MemoryFile to delay eviction of "optional" allocations, such as unused cached file pages. Note that this incidentally makes CachingInodeOperations writeback asynchronous, in the sense that it doesn't occur until eviction; this is necessary because between when a cached page becomes evictable and when it's evicted, file writes (via CachingInodeOperations.Write) may dirty the page. As currently implemented, this feature won't meaningfully impact steady-state memory usage or caching; the reclaimer goroutine will schedule eviction as soon as it runs out of other work to do. Future CLs increase caching by adding constraints on when eviction is scheduled. PiperOrigin-RevId: 246014822 Change-Id: Ia85feb25a2de92a48359eb84434b6ec6f9bea2cb
2019-04-29Change copyright notice to "The gVisor Authors"Michael Pratt
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
2019-04-25Perform explicit CPUID and FP state compatibility checks on restoreMichael Pratt
PiperOrigin-RevId: 245341004 Change-Id: Ic4d581039d034a8ae944b43e45e84eb2c3973657
2019-04-22Clean up state error handlingMichael Pratt
PiperOrigin-RevId: 244773836 Change-Id: I32223f79d2314fe1ac4ddfc63004fc22ff634adf
2019-04-17Use FD limit and file size limit from hostFabricio Voznika
FD limit and file size limit is read from the host, instead of using hard-coded defaults, given that they effect the sandbox process. Also limit the direct cache to use no more than half if the available FDs. PiperOrigin-RevId: 244050323 Change-Id: I787ad0fdf07c49d589e51aebfeae477324fe26e6
2019-04-10Fix uses of RootFromContext.Nicolas Lacasse
RootFromContext can return a dirent with reference taken, or nil. We must call DecRef if (and only if) a real dirent is returned. PiperOrigin-RevId: 242965515 Change-Id: Ie2b7b4cb19ee09b6ccf788b71f3fd7efcdf35a11
2019-04-10Start saving MountSource.DirentCache.Nicolas Lacasse
DirentCache is already a savable type, and it ensures that it is empty at the point of Save. There is no reason not to save it along with the MountSource. This did uncover an issue where not all MountSources were properly flushed before Save. If a mount point has an open file and is then unmounted, we save the MountSource without flushing it first. This CL also fixes that by flushing all MountSources for all open FDs on Save. PiperOrigin-RevId: 242906637 Change-Id: I3acd9d52b6ce6b8c989f835a408016cb3e67018f
2019-04-03Cache ThreadGroups in PIDNamespaceMichael Pratt
If there are thousands of threads, ThreadGroupsAppend becomes very expensive as it must iterate over all Tasks to find the ThreadGroup leaders. Reduce the cost by maintaining a map of ThreadGroups which can be used to grab them all directly. The one somewhat visible change is to convert PID namespace init children zapping to a group-directed SIGKILL, as Linux did in 82058d668465 "signal: Use group_send_sig_info to kill all processes in a pid namespace". In a benchmark that creates N threads which sleep for two minutes, we see approximately this much CPU time in ThreadGroupsAppend: Before: 1 thread: 0ms 1024 threads: 30ms - 9130ms 4096 threads: 50ms - 2000ms 8192 threads: 18160ms 16384 threads: 17210ms After: 1 thread: 0ms 1024 threads: 0ms 4096 threads: 0ms 8192 threads: 0ms 16384 threads: 0ms The profiling is actually extremely noisy (likely due to cache effects), as some runs show almost no samples at 1024, 4096 threads, but obviously this does not scale to lots of threads. PiperOrigin-RevId: 241828039 Change-Id: I17827c90045df4b3c49b3174f3a05bca3026a72c
2019-04-01Save/restore simple devices.Rahat Mahmood
We weren't saving simple devices' last allocated inode numbers, which caused inode number reuse across S/R. PiperOrigin-RevId: 241414245 Change-Id: I964289978841ef0a57d2fa48daf8eab7633c1284
2019-03-29Treat fsync errors during save as SaveRejection errors.Nicolas Lacasse
PiperOrigin-RevId: 241055485 Change-Id: I70259e9fef59bdf9733b35a2cd3319359449dd45
2019-03-29Treat ENOSPC as a state-file error during save.Nicolas Lacasse
PiperOrigin-RevId: 241028806 Change-Id: I770bf751a2740869a93c3ab50370a727ae580470
2019-03-14Decouple filemem from platform and move it to pgalloc.MemoryFile.Jamie Liu
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
2019-02-14Don't allow writing or reading to TTY unless process group is in foreground.Nicolas Lacasse
If a background process tries to read from a TTY, linux sends it a SIGTTIN unless the signal is blocked or ignored, or the process group is an orphan, in which case the syscall returns EIO. See drivers/tty/n_tty.c:n_tty_read()=>job_control(). If a background process tries to write a TTY, set the termios, or set the foreground process group, linux then sends a SIGTTOU. If the signal is ignored or blocked, linux allows the write. If the process group is an orphan, the syscall returns EIO. See drivers/tty/tty_io.c:tty_check_change(). PiperOrigin-RevId: 234044367 Change-Id: I009461352ac4f3f11c5d42c43ac36bb0caa580f9