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2020-11-03Merge release-20201027.0-61-g723464ec5 (automated)gVisor bot
2020-11-03Make pipe min/max sizes match linux.Nicolas Lacasse
The default pipe size already matched linux, and is unchanged. Furthermore `atomicIOBytes` is made a proper constant (as it is in Linux). We were plumbing usermem.PageSize everywhere, so this is no functional change. PiperOrigin-RevId: 340497006
2020-11-03Merge release-20201027.0-56-g1a3f417f4 (automated)gVisor bot
2020-11-02Implement command GETZCNT for semctl.Jing Chen
PiperOrigin-RevId: 340389884
2020-10-30Merge release-20201019.0-111-g9ad864628 (automated)gVisor bot
2020-10-30Separate kernel.Task.AsCopyContext() into CopyContext() and OwnCopyContext().Jamie Liu
kernel.copyContext{t} cannot be used outside of t's task goroutine, for three reasons: - t.CopyScratchBuffer() is task-goroutine-local. - Calling t.MemoryManager() without running on t's task goroutine or locking t.mu violates t.MemoryManager()'s preconditions. - kernel.copyContext passes t as context.Context to MM IO methods, which is illegal outside of t's task goroutine (cf. kernel.Task.Value()). Fix this by splitting AsCopyContext() into CopyContext() (which takes an explicit context.Context and is usable outside of the task goroutine) and OwnCopyContext() (which uses t as context.Context, but is only usable by t's task goroutine). PiperOrigin-RevId: 339933809
2020-10-29Merge release-20201019.0-95-g3b4674ffe (automated)gVisor bot
2020-10-27Merge release-20201019.0-65-gfacb2fb9c (automated)gVisor bot
2020-10-26Implement command IPC_STAT for semctl.Jing Chen
PiperOrigin-RevId: 339166854
2020-10-24Merge release-20201019.0-51-g9f87400f0 (automated)gVisor bot
2020-10-23Support VFS2 save/restore.Jamie Liu
Inode number consistency checks are now skipped in save/restore tests for reasons described in greatest detail in StatTest.StateDoesntChangeAfterRename. They pass in VFS1 due to the bug described in new test case SimpleStatTest.DifferentFilesHaveDifferentDeviceInodeNumberPairs. Fixes #1663 PiperOrigin-RevId: 338776148
2020-10-23Merge release-20201019.0-34-g9ca66ec59 (automated)gVisor bot
2020-10-23Rewrite reference leak checker without finalizers.Dean Deng
Our current reference leak checker uses finalizers to verify whether an object has reached zero references before it is garbage collected. There are multiple problems with this mechanism, so a rewrite is in order. With finalizers, there is no way to guarantee that a finalizer will run before the program exits. When an unreachable object with a finalizer is garbage collected, its finalizer will be added to a queue and run asynchronously. The best we can do is run garbage collection upon sandbox exit to make sure that all finalizers are enqueued. Furthermore, if there is a chain of finalized objects, e.g. A points to B points to C, garbage collection needs to run multiple times before all of the finalizers are enqueued. The first GC run will register the finalizer for A but not free it. It takes another GC run to free A, at which point B's finalizer can be registered. As a result, we need to run GC as many times as the length of the longest such chain to have a somewhat reliable leak checker. Finally, a cyclical chain of structs pointing to one another will never be garbage collected if a finalizer is set. This is a well-known issue with Go finalizers (https://github.com/golang/go/issues/7358). Using leak checking on filesystem objects that produce cycles will not work and even result in memory leaks. The new leak checker stores reference counted objects in a global map when leak check is enabled and removes them once they are destroyed. At sandbox exit, any remaining objects in the map are considered as leaked. This provides a deterministic way of detecting leaks without relying on the complexities of finalizers and garbage collection. This approach has several benefits over the former, including: - Always detects leaks of objects that should be destroyed very close to sandbox exit. The old checker very rarely detected these leaks, because it relied on garbage collection to be run in a short window of time. - Panics if we forgot to enable leak check on a ref-counted object (we will try to remove it from the map when it is destroyed, but it will never have been added). - Can store extra logging information in the map values without adding to the size of the ref count struct itself. With the size of just an int64, the ref count object remains compact, meaning frequent operations like IncRef/DecRef are more cache-efficient. - Can aggregate leak results in a single report after the sandbox exits. Instead of having warnings littered in the log, which were non-deterministically triggered by garbage collection, we can print all warning messages at once. Note that this could also be a limitation--the sandbox must exit properly for leaks to be detected. Some basic benchmarking indicates that this change does not significantly affect performance when leak checking is enabled, which is understandable since registering/unregistering is only done once for each filesystem object. Updates #1486. PiperOrigin-RevId: 338685972
2020-10-22Merge release-20201019.0-28-g4e389c785 (automated)gVisor bot
2020-10-21Check for nil in kernel.FSContext functions.Dean Deng
Reported-by: syzbot+c0e175d2b10708314eb3@syzkaller.appspotmail.com PiperOrigin-RevId: 338386575
2020-10-20Merge release-20201005.0-107-gdcc1b71f1 (automated)gVisor bot
2020-10-19Fix reference counting on kcov mappings.Dean Deng
Reported-by: syzbot+078580ce5dd6d607fcd8@syzkaller.appspotmail.com Reported-by: syzbot+2096681f6891e7bf8aed@syzkaller.appspotmail.com PiperOrigin-RevId: 337973519
2020-10-20Merge release-20201005.0-104-gcd86bd493 (automated)gVisor bot
2020-10-19Fix runsc tests on VFS2 overlay.Jamie Liu
- Check the sticky bit in overlay.filesystem.UnlinkAt(). Fixes StickyTest.StickyBitPermDenied. - When configuring a VFS2 overlay in runsc, copy the lower layer's root owner/group/mode to the upper layer's root (as in the VFS1 equivalent, boot.addOverlay()). This makes the overlay root owned by UID/GID 65534 with mode 0755 rather than owned by UID/GID 0 with mode 01777. Fixes CreateTest.CreateFailsOnUnpermittedDir, which assumes that the test cannot create files in /. - MknodTest.UnimplementedTypesReturnError assumes that the creation of device special files is not supported. However, while the VFS2 gofer client still doesn't support device special files, VFS2 tmpfs does, and in the overlay test dimension mknod() targets a tmpfs upper layer. The test initially has all capabilities, including CAP_MKNOD, so its creation of these files succeeds. Constrain these tests to VFS1. - Rename overlay.nonDirectoryFD to overlay.regularFileFD and only use it for regular files, using the original FD for pipes and device special files. This is more consistent with Linux (which gets the original inode_operations, and therefore file_operations, for these file types from ovl_fill_inode() => init_special_inode()) and fixes remaining mknod and pipe tests. - Read/write 1KB at a time in PipeTest.Streaming, rather than 4 bytes. This isn't strictly necessary, but it makes the test less obnoxiously slow on ptrace. Fixes #4407 PiperOrigin-RevId: 337971042
2020-10-19Merge release-20201005.0-102-g54e989ec3 (automated)gVisor bot
2020-10-19Merge release-20201005.0-100-g63f4cef4d (automated)gVisor bot
2020-10-19[vfs2] Fix fork reference leaks.Dean Deng
PiperOrigin-RevId: 337919424
2020-10-14Merge release-20200928.0-115-ga7b7b7b98 (automated)gVisor bot
2020-10-14Fix shm reference leak.Dean Deng
All shm segments in an IPC namespace should be released once that namespace is destroyed. Add reference counting to IPCNamespace so that once the last task with a reference on it exits, we can trigger a destructor that will clean up all shm segments that have not been explicitly freed by the application. PiperOrigin-RevId: 337032977
2020-10-13Merge release-20200928.0-102-g432963dd2 (automated)gVisor bot
2020-10-13[vfs2] Don't take reference in Task.MountNamespaceVFS2 and MountNamespace.Root.Dean Deng
This fixes reference leaks related to accidentally forgetting to DecRef() after calling one or the other. PiperOrigin-RevId: 336918922
2020-10-13Merge release-20200928.0-98-gfc7df5322 (automated)gVisor bot
2020-10-13Don't leak VDSO mappings.Dean Deng
PiperOrigin-RevId: 336822021
2020-10-12Merge release-20200928.0-91-gd861cd5f1 (automated)gVisor bot
2020-10-12[vfs2] Don't leak disconnected mounts.Dean Deng
PiperOrigin-RevId: 336694658
2020-10-09Merge release-20200928.0-81-g6bbf66227 (automated)gVisor bot
2020-10-09Reduce the cost of sysinfo(2).Jamie Liu
- sysinfo(2) does not actually require a fine-grained breakdown of memory usage. Accordingly, instead of calling pgalloc.MemoryFile.UpdateUsage() to update the sentry's fine-grained memory accounting snapshot, just use pgalloc.MemoryFile.TotalUsage() (which is a single fstat(), and therefore far cheaper). - Use the number of threads in the root PID namespace (i.e. globally) rather than in the task's PID namespace for consistency with Linux (which just reads global variable nr_threads), and add a new method to kernel.PIDNamespace to allow this to be read directly from an underlying map rather than requiring the allocation and population of an intermediate slice. PiperOrigin-RevId: 336353100
2020-10-09Merge release-20200928.0-78-g743327817 (automated)gVisor bot
2020-10-08Merge release-20200928.0-66-ga55bd73d4 (automated)gVisor bot
2020-10-06Merge release-20200928.0-49-ga1df7f2ed (automated)gVisor bot
2020-10-05Simplify nil assignment in kcov.Dean Deng
PiperOrigin-RevId: 335548610
2020-10-03Merge release-20200921.0-107-ge0aaf40e3 (automated)gVisor bot
2020-10-03Fix kcov enabling and disabling procedures.Dean Deng
- When the KCOV_ENABLE_TRACE ioctl is called with the trace kind KCOV_TRACE_PC, the kcov mode should be set to KCOV_*MODE*_TRACE_PC. - When the owning task of kcov exits, the memory mapping should not be cleared so it can be used by other tasks. - Add more tests (also tested on native Linux kcov). PiperOrigin-RevId: 335202585
2020-10-02Merge release-20200921.0-102-g4f462b0ed (automated)gVisor bot
2020-10-02Convert uses of the binary package in kernel to go-marshal.Rahat Mahmood
PiperOrigin-RevId: 335077195
2020-09-30Merge release-20200921.0-74-g387501219 (automated)gVisor bot
2020-09-29Replace remaining uses of reflection-based marshalling.Rahat Mahmood
- Rewrite arch.Stack.{Push,Pop}. For the most part, stack now implements marshal.CopyContext and can be used as the target of marshal operations. Stack.Push had some extra logic for automatically null-terminating slices. This was only used for two specific types of slices, and is now handled explicitly. - Delete usermem.CopyObject{In,Out}. - Replace most remaining uses of the encoding/binary package with go-marshal. Most of these were using the binary package to compute the size of a struct, which go-marshal can directly replace. ~3 uses of the binary package remain. These aren't reasonably replaceable by go-marshal: for example one use is to construct the syscall trampoline for systrap. - Fill out remaining convenience wrappers in the primitive package. PiperOrigin-RevId: 334502375
2020-09-29Merge release-20200921.0-66-g7d64bc1fd (automated)gVisor bot
2020-09-29Merge pull request #3875 from btw616:fix/issue-3874gVisor bot
PiperOrigin-RevId: 334428344
2020-09-27Merge release-20200921.0-53-g2a60f9229 (automated)gVisor bot
2020-09-27Clean up kcov.Dean Deng
Previously, we did not check the kcov mode when performing task work. As a result, disabling kcov did not do anything. Also avoid expensive atomic RMW when consuming coverage data. We don't need the swap if the value is already zero (which is most of the time), and it is ok if there are slight inconsistencies due to a race between coverage data generation (incrementing the value) and consumption (reading a nonzero value and writing zero). PiperOrigin-RevId: 334049207
2020-09-24Merge release-20200914.0-152-g0a7075f38 (automated)gVisor bot
2020-09-24Add basic stateify annotations.Adin Scannell
Updates #1663 PiperOrigin-RevId: 333539293
2020-09-24Fix socket record leak in VFS2Tiwei Bie
VFS2 socket record is not removed from the system-wide socket table when the socket is released, which will lead to a memory leak. This patch fixes this issue. Fixes: #3874 Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
2020-09-24Rename kernel.SocketEntry to kernel.SocketRecordTiwei Bie
SocketEntry can be confusing with the template types as the 'Entry' is usually used as a suffix for list element types, e.g. socketEntry in the same package. Suggested by Dean (@dean-deng). Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>