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path: root/pkg/sentry/kernel/threads.go
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2021-04-02Implement cgroupfs.Rahat Mahmood
A skeleton implementation of cgroupfs. It supports trivial cpu and memory controllers with no support for hierarchies. PiperOrigin-RevId: 366561126
2021-02-24Add YAMA security module restrictions on ptrace(2).Dean Deng
Restrict ptrace(2) according to the default configurations of the YAMA security module (mode 1), which is a common default among various Linux distributions. The new access checks only permit the tracer to proceed if one of the following conditions is met: a) The tracer is already attached to the tracee. b) The target is a descendant of the tracer. c) The target has explicitly given permission to the tracer through the PR_SET_PTRACER prctl. d) The tracer has CAP_SYS_PTRACE. See security/yama/yama_lsm.c for more details. Note that these checks are added to CanTrace, which is checked for PTRACE_ATTACH as well as some other operations, e.g., checking a process' memory layout through /proc/[pid]/mem. Since this patch adds restrictions to ptrace, it may break compatibility for applications run by non-root users that, for instance, rely on being able to trace processes that are not descended from the tracer (e.g., `gdb -p`). YAMA restrictions can be turned off by setting /proc/sys/kernel/yama/ptrace_scope to 0, or exceptions can be made on a per-process basis with the PR_SET_PTRACER prctl. Reported-by: syzbot+622822d8bca08c99e8c8@syzkaller.appspotmail.com PiperOrigin-RevId: 359237723
2021-01-22Implement F_GETLK fcntl.Dean Deng
Fixes #5113. PiperOrigin-RevId: 353313374
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
2020-09-15Enable automated marshalling for the syscall package.Rahat Mahmood
PiperOrigin-RevId: 331940975
2020-06-16Port aio to VFS2.Nicolas Lacasse
In order to make sure all aio goroutines have stopped during S/R, a new WaitGroup was added to TaskSet, analagous to runningGoroutines. This WaitGroup is incremented with each aio goroutine, and waited on during kernel.Pause. The old VFS1 aio code was changed to use this new WaitGroup, rather than fs.Async. The only uses of fs.Async are now inode and mount Release operations, which do not call fs.Async recursively. This fixes a lock-ordering violation that can cause deadlocks. Updates #1035. PiperOrigin-RevId: 316689380
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
2019-07-26Merge pull request #452 from zhangningdlut:chris_test_pidnsgVisor bot
PiperOrigin-RevId: 260220279
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
2019-04-29Change 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
2019-04-04Remove defer from trivial ThreadID methodsMichael Pratt
In particular, ns.IDOfTask and tg.ID are used for gettid and getpid, respectively, where removing defer saves ~100ns. This may be a small improvement to application logging, which may call gettid/getpid frequently. PiperOrigin-RevId: 242039616 Change-Id: I860beb62db3fe077519835e6bafa7c74cba6ca80
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
2018-10-19Use correct company name in copyright headerIan Gudger
PiperOrigin-RevId: 217951017 Change-Id: Ie08bf6987f98467d07457bcf35b5f1ff6e43c035
2018-10-17Check thread group CPU timers in the CPU clock ticker.Jamie Liu
This reduces the number of goroutines and runtime timers when ITIMER_VIRTUAL or ITIMER_PROF are enabled, or when RLIMIT_CPU is set. This also ensures that thread group CPU timers only advance if running tasks are observed at the time the CPU clock advances, mostly eliminating the possibility that a CPU timer expiration observes no running tasks and falls back to the group leader. PiperOrigin-RevId: 217603396 Change-Id: Ia24ce934d5574334857d9afb5ad8ca0b6a6e65f4
2018-08-07Hold TaskSet.mu in Task.Parent.Jamie Liu
PiperOrigin-RevId: 207766238 Change-Id: Id3b66d8fe1f44c3570f67fa5ae7ba16021e35be1
2018-08-02Automated rollback of changelist 207037226Zhaozhong Ni
PiperOrigin-RevId: 207125440 Change-Id: I6c572afb4d693ee72a0c458a988b0e96d191cd49
2018-08-01Automated rollback of changelist 207007153Michael Pratt
PiperOrigin-RevId: 207037226 Change-Id: I8b5f1a056d4f3eab17846f2e0193bb737ecb5428
2018-08-01stateify: convert all packages to use explicit mode.Zhaozhong Ni
PiperOrigin-RevId: 207007153 Change-Id: Ifedf1cc3758dc18be16647a4ece9c840c1c636c9
2018-04-28Check in gVisor.Googler
PiperOrigin-RevId: 194583126 Change-Id: Ica1d8821a90f74e7e745962d71801c598c652463