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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
2020-10-19Fix 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
2020-10-19[vfs2] Fix fork reference leaks.Dean Deng
PiperOrigin-RevId: 337919424
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
2020-10-13[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
2020-10-13Don't leak VDSO mappings.Dean Deng
PiperOrigin-RevId: 336822021
2020-10-12[vfs2] Don't leak disconnected mounts.Dean Deng
PiperOrigin-RevId: 336694658
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
2020-10-05Simplify nil assignment in kcov.Dean Deng
PiperOrigin-RevId: 335548610
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
2020-10-02Convert uses of the binary package in kernel to go-marshal.Rahat Mahmood
PiperOrigin-RevId: 335077195
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 pull request #3875 from btw616:fix/issue-3874gVisor bot
PiperOrigin-RevId: 334428344
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
2020-09-24Add 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>
2020-09-22Handle EOF properly in splice/sendfile.Dean Deng
Use HandleIOErrorVFS2 instead of custom error handling. PiperOrigin-RevId: 333227581
2020-09-17Complete vfs2 implementation of fallocate.Dean Deng
This change includes overlay, special regular gofer files, and hostfs. Fixes #3589. PiperOrigin-RevId: 332330860
2020-09-16Rename marshal.Task to marshal.CopyContext.Rahat Mahmood
CopyContext is a better name for the interface because from go-marshal's perspective, the interface has nothing to do with a task. A kernel.Task happens to implement the interface, but so can other things like MemoryManager and IO sequences. PiperOrigin-RevId: 331959678
2020-09-15Enable automated marshalling for the syscall package.Rahat Mahmood
PiperOrigin-RevId: 331940975
2020-09-15Add support for OCI seccomp filters in the sandbox.Ian Lewis
OCI configuration includes support for specifying seccomp filters. In runc, these filter configurations are converted into seccomp BPF programs and loaded into the kernel via libseccomp. runsc needs to be a static binary so, for runsc, we cannot rely on a C library and need to implement the functionality in Go. The generator added here implements basic support for taking OCI seccomp configuration and converting it into a seccomp BPF program with the same behavior as a program generated by libseccomp. - New conditional operations were added to pkg/seccomp to support operations available in OCI. - AllowAny and AllowValue were renamed to MatchAny and EqualTo to better reflect that syscalls matching the conditionals result in the provided action not simply SCMP_RET_ALLOW. - BuildProgram in pkg/seccomp no longer panics if provided an empty list of rules. It now builds a program with the architecture sanity check only. - ProgramBuilder now allows adding labels that are unused. However, backwards jumps are still not permitted. Fixes #510 PiperOrigin-RevId: 331938697
2020-09-15Release FDTable lock before dropping the fds.Nayana Bidari
This is needed for SO_LINGER, where close() is blocked for linger timeout and we are holding the FDTable lock for the entire timeout which will not allow us to create/delete other fds. We have to release the locks and then drop the fds. PiperOrigin-RevId: 331844185
2020-09-14Correct FDSize in /proc/[pid]/status.Jamie Liu
In Linux, FDSize is fs/proc/array.c:task_state() => struct fdtable::max_fds, which is set to the underlying array's length in fs/file.c:alloc_fdtable(). Follow-up changes: - Remove FDTable.GetRefs() and FDTable.GetRefsVFS2(), which are unused. - Reset FDTable.used to 0 during restore, since the subsequent calls to FDTable.setAll() increment it again, causing its value to be doubled. (After this CL, FDTable.used is only used to avoid reallocation in FDTable.GetFDs(), so this fix is not very visible.) PiperOrigin-RevId: 331588190
2020-09-11Move the 'marshal' and 'primitive' packages to the 'pkg' directory.Rahat Mahmood
PiperOrigin-RevId: 331256608
2020-09-08Fix the use after nil check on args.MountNamespaceVFS2Tiwei Bie
The args.MountNamespaceVFS2 is used again after the nil check, instead, mntnsVFS2 which holds the expected reference should be used. This patch fixes this issue. Fixes: #3855 Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
2020-09-01Fix panic when calling dup2().Nayana Bidari
PiperOrigin-RevId: 329572337
2020-08-27Fix vfs2 pipe behavior when splicing to a non-pipe.Dean Deng
Fixes *.sh Java runtime tests, where splice()-ing from a pipe to /dev/zero would not actually empty the pipe. There was no guarantee that the data would actually be consumed on a splice operation unless the output file's implementation of Write/PWrite actually called VFSPipeFD.CopyIn. Now, whatever bytes are "written" are consumed regardless of whether CopyIn is called or not. Furthermore, the number of bytes in the IOSequence for reads is now capped at the amount of data actually available. Before, splicing to /dev/zero would always return the requested splice size without taking the actual available data into account. This change also refactors the case where an input file is spliced into an output pipe so that it follows a similar pattern, which is arguably cleaner anyway. Updates #3576. PiperOrigin-RevId: 328843954
2020-08-27[go-marshal] Support for usermem.IOOpts.Ayush Ranjan
PiperOrigin-RevId: 328839759
2020-08-25Use new reference count utility throughout gvisor.Dean Deng
This uses the refs_vfs2 template in vfs2 as well as objects common to vfs1 and vfs2. Note that vfs1-only refcounts are not replaced, since vfs1 will be deleted soon anyway. The following structs now use the new tool, with leak check enabled: devpts:rootInode fuse:inode kernfs:Dentry kernfs:dir kernfs:readonlyDir kernfs:StaticDirectory proc:fdDirInode proc:fdInfoDirInode proc:subtasksInode proc:taskInode proc:tasksInode vfs:FileDescription vfs:MountNamespace vfs:Filesystem sys:dir kernel:FSContext kernel:ProcessGroup kernel:Session shm:Shm mm:aioMappable mm:SpecialMappable transport:queue And the following use the template, but because they currently are not leak checked, a TODO is left instead of enabling leak check in this patch: kernel:FDTable tun:tunEndpoint Updates #1486. PiperOrigin-RevId: 328460377
2020-08-25Expose basic coverage information to userspace through kcov interface.Dean Deng
In Linux, a kernel configuration is set that compiles the kernel with a custom function that is called at the beginning of every basic block, which updates the memory-mapped coverage information. The Go coverage tool does not allow us to inject arbitrary instructions into basic blocks, but it does provide data that we can convert to a kcov-like format and transfer them to userspace through a memory mapping. Note that this is not a strict implementation of kcov, which is especially tricky to do because we do not have the same coverage tools available in Go that that are available for the actual Linux kernel. In Linux, a kernel configuration is set that compiles the kernel with a custom function that is called at the beginning of every basic block to write program counters to the kcov memory mapping. In Go, however, coverage tools only give us a count of basic blocks as they are executed. Every time we return to userspace, we collect the coverage information and write out PCs for each block that was executed, providing userspace with the illusion that the kcov data is always up to date. For convenience, we also generate a unique synthetic PC for each block instead of using actual PCs. Finally, we do not provide thread-specific coverage data (each kcov instance only contains PCs executed by the thread owning it); instead, we will supply data for any file specified by -- instrumentation_filter. Also, fix issue in nogo that was causing pkg/coverage:coverage_nogo compilation to fail. PiperOrigin-RevId: 328426526
2020-08-21Pass overlay credentials via context in copy up.Nicolas Lacasse
Some VFS operations (those which operate on FDs) get their credentials via the context instead of via an explicit creds param. For these cases, we must pass the overlay credentials on the context. PiperOrigin-RevId: 327881259
2020-08-20Consistent precondition formattingMichael Pratt
Our "Preconditions:" blocks are very useful to determine the input invariants, but they are bit inconsistent throughout the codebase, which makes them harder to read (particularly cases with 5+ conditions in a single paragraph). I've reformatted all of the cases to fit in simple rules: 1. Cases with a single condition are placed on a single line. 2. Cases with multiple conditions are placed in a bulleted list. This format has been added to the style guide. I've also mentioned "Postconditions:", though those are much less frequently used, and all uses already match this style. PiperOrigin-RevId: 327687465
2020-08-18Move ERESTART* error definitions to syserror package.Dean Deng
This is needed to avoid circular dependencies between the vfs and kernel packages. PiperOrigin-RevId: 327355524
2020-08-17Remove weak references from unix sockets.Dean Deng
The abstract socket namespace no longer holds any references on sockets. Instead, TryIncRef() is used when a socket is being retrieved in BoundEndpoint(). Abstract sockets are now responsible for removing themselves from the namespace they are in, when they are destroyed. Updates #1486. PiperOrigin-RevId: 327064173
2020-08-07Add context.FullStateChanged()Andrei Vagin
It indicates that the Sentry has changed the state of the thread and next calls of PullFullState() has to do nothing. PiperOrigin-RevId: 325567415
2020-08-03Add callbacks to support lazy loading/restoring thread statesAndrei Vagin
PiperOrigin-RevId: 324748508
2020-08-03Plumbing context.Context to DecRef() and Release().Nayana Bidari
context is passed to DecRef() and Release() which is needed for SO_LINGER implementation. PiperOrigin-RevId: 324672584
2020-07-27Move platform.File in memmapAndrei Vagin
The subsequent systrap changes will need to import memmap from the platform package. PiperOrigin-RevId: 323409486
2020-07-23Add AfterFunc to tcpip.ClockSam Balana
Changes the API of tcpip.Clock to also provide a method for scheduling and rescheduling work after a specified duration. This change also implements the AfterFunc method for existing implementations of tcpip.Clock. This is the groundwork required to mock time within tests. All references to CancellableTimer has been replaced with the tcpip.Job interface, allowing for custom implementations of scheduling work. This is a BREAKING CHANGE for clients that implement their own tcpip.Clock or use tcpip.CancellableTimer. Migration plan: 1. Add AfterFunc(d, f) to tcpip.Clock 2. Replace references of tcpip.CancellableTimer with tcpip.Job 3. Replace calls to tcpip.CancellableTimer#StopLocked with tcpip.Job#Cancel 4. Replace calls to tcpip.CancellableTimer#Reset with tcpip.Job#Schedule 5. Replace calls to tcpip.NewCancellableTimer with tcpip.NewJob. PiperOrigin-RevId: 322906897
2020-07-23Implement get/set_robust_list.Nicolas Lacasse
PiperOrigin-RevId: 322904430
2020-07-23Add task work mechanism.Dean Deng
Like task_work in Linux, this allows us to register callbacks to be executed before returning to userspace. This is needed for kcov support, which requires coverage information to be up-to-date whenever we are in user mode. We will provide coverage data through the kcov interface to enable coverage-directed fuzzing in syzkaller. One difference from Linux is that task work cannot queue work before the transition to userspace that it precedes; queued work will be picked up before the next transition. PiperOrigin-RevId: 322889984
2020-07-15Merge pull request #3165 from ridwanmsharif:ridwanmsharif/fuse-off-by-defaultgVisor bot
PiperOrigin-RevId: 321411758
2020-07-13Disable debug time adjustment loggingFabricio Voznika
When --debug is enabled, the following log messages are printed every second filling up the log: D0430 18:04:42.823775 129561 parameters.go:238] Clock(Monotonic): error: 46 ns, adjusted frequency from 3591713733 Hz to 3591714196 Hz D0430 18:04:42.823870 129561 parameters.go:238] Clock(Realtime): error: 36 ns, adjusted frequency from 3591714003 Hz to 3591714169 Hz D0430 18:04:42.823892 129561 timekeeper.go:209] Updating VDSO parameters: {monotonicReady:1 monotonicBaseCycles:15758797714254696 monotonicBaseRef:29000233837 monotonicFrequency:3591714196 realtimeReady:1 realtimeBaseCycles:15758797714610880 realtimeBaseRef:1588269882823867374 realtimeFrequency:3591714169} Info and warning messages for larger changes are kept the same. PiperOrigin-RevId: 321048523
2020-07-09Gate FUSE behind a runsc flagRidwan Sharif
This change gates all FUSE commands (by gating /dev/fuse) behind a runsc flag. In order to use FUSE commands, use the --fuse flag with the --vfs2 flag. Check if FUSE is enabled by running dmesg in the sandbox.
2020-07-01Port fallocate to VFS2.Zach Koopmans
PiperOrigin-RevId: 319283715
2020-07-01Complete async signal delivery support in vfs2.Dean Deng
- Support FIOASYNC, FIO{SET,GET}OWN, SIOC{G,S}PGRP (refactor getting/setting owner in the process). - Unset signal recipient when setting owner with pid == 0 and valid owner type. Updates #2923. PiperOrigin-RevId: 319231420
2020-06-27Port GETOWN, SETOWN fcntls to vfs2.Dean Deng
Also make some fixes to vfs1's F_SETOWN. The fcntl test now entirely passes on vfs2. Fixes #2920. PiperOrigin-RevId: 318669529
2020-06-26Require CAP_SYS_ADMIN in the root user namespace for TTY theftKevin Krakauer
PiperOrigin-RevId: 318563543
2020-06-25Avoid an allocation in epollTamir Duberstein
PiperOrigin-RevId: 318346153