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
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
Adds support level documentation for all syscalls. Removes the Undocumented
utility function to discourage usage while leaving SupportUndocumented as the
default support level for Syscall structs.
PiperOrigin-RevId: 256281927
fileOpAt holds references on the Dirents passed as arguments to the callback,
and drops refs when finished, so we don't need to DecRef those Dirents
ourselves
However, all Dirents that we get from FindInode/FindLink must be DecRef'd.
This CL cleans up the ref-counting logic, and fixes some refcount issues in the
process.
PiperOrigin-RevId: 256220882
Fix two leaks for connectionless Unix sockets:
* Double connect: Subsequent connects would leak a reference on the previously
connected endpoint.
* Close unconnected: Sockets which were not connected at the time of closure
would leak a reference on their receiver.
PiperOrigin-RevId: 256070451
These syscalls require filesystem support that gVisor does not provide, and is
not planning to implement. Their absense should not trigger an event.
PiperOrigin-RevId: 255692871
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
Get/Set pipe size and ioctl support were missing from
overlayfs. It required moving the pipe.Sizer interface
to fs so that overlay could get access.
Fixes#318
PiperOrigin-RevId: 255511125
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
Currently, the overlay dirCache is only used for a single logical use of
getdents. i.e., it is discard when the FD is closed or seeked back to
the beginning.
But the initial work of getting the directory contents can be quite
expensive (particularly sorting large directories), so we should keep it
as long as possible.
This is very similar to the readdirCache in fs/gofer.
Since the upper filesystem does not have to allow caching readdir
entries, the new CacheReaddir MountSourceOperations method controls this
behavior.
This caching should be trivially movable to all Inodes if desired,
though that adds an additional copy step for non-overlay Inodes.
(Overlay Inodes already do the extra copy).
PiperOrigin-RevId: 255477592
The code was wrongly assuming that only read access was
required from the lower overlay when checking for permissions.
This allowed non-writable files to be writable in the overlay.
Fixes#316
PiperOrigin-RevId: 255263686
If we have a symlink whose target does not exist, creating the symlink (either
via 'creat' or 'open' with O_CREAT flag) should create the target of the
symlink. Previously, gVisor would error with EEXIST in this case
PiperOrigin-RevId: 255232944
Go was going to change the behavior of SysProcAttr.Ctty such that it must be an
FD in the *parent* FD table:
https://go-review.googlesource.com/c/go/+/178919/
However, after some debate, it was decided that this change was too
backwards-incompatible, and so it was reverted.
https://github.com/golang/go/issues/29458
The behavior going forward is unchanged: the Ctty FD must be an FD in the
*child* FD table.
PiperOrigin-RevId: 255228476
An upcoming change in Go 1.13 [1] changes the semantics of the SysProcAttr.Ctty
field. Prior to the change, the FD must be an FD in the child process's FD
table (aka "post-shuffle"). After the change, the FD must be an FD in the
current process's FD table (aka "pre-shuffle").
To be compatible with both versions this CL introduces a new boolean
"CttyFdIsPostShuffle" which indicates whether a pre- or post-shuffle FD should
be provided. We use build tags to chose the correct one.
1: https://go-review.googlesource.com/c/go/+/178919/
PiperOrigin-RevId: 255015303
Credentials are immutable and even before these changes we could read them
without locks, but we needed to take a task lock to get a credential object
from a task object.
It is possible to avoid this lock, if we will guarantee that a credential
object will not be changed after setting it on a task.
PiperOrigin-RevId: 254989492
When we reopen file by path, we can't be sure that
we will open exactly the same file. The file can be
deleted and another one with the same name can be
created.
PiperOrigin-RevId: 254898594
For files with O_APPEND, a file write operation gets a file size and uses it as
offset to call an inode write operation. This means that all other operations
which can change a file size should be blocked while the write operation doesn't
complete.
PiperOrigin-RevId: 254873771
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
The previous number was for the arm architecture.
Also change the statx tests to force them to run on gVisor, which would have
caught this issue.
PiperOrigin-RevId: 254846831
Tests run at HEAD (35719d52):
```
$ bazel test $(bazel query 'filter(".*getdents.*", //test/syscalls:all)')
<snip>
//test/syscalls:getdents_test_native PASSED in 0.3s
//test/syscalls:getdents_test_runsc_ptrace PASSED in 4.9s
//test/syscalls:getdents_test_runsc_ptrace_overlay PASSED in 4.7s
//test/syscalls:getdents_test_runsc_ptrace_shared PASSED in 5.2s
//test/syscalls:getdents_test_runsc_kvm FAILED in 4.0s
```
Tests run at ab6774ce~1 (6f933a93):
```
$ bazel test $(bazel query 'filter(".*getdents.*", //test/syscalls:all)')
//test/syscalls:getdents_test_native PASSED in 0.2s
//test/syscalls:getdents_test_runsc_kvm FAILED in 4.2s
/usr/local/google/home/brb/.cache/bazel/_bazel_brb/967240a6aae7d353a221d73f4375e038/execroot/__main__/bazel-out/k8-fastbuild/testlogs/test/syscalls/getdents_test_runsc_kvm/test.log
//test/syscalls:getdents_test_runsc_ptrace FAILED in 5.3s
/usr/local/google/home/brb/.cache/bazel/_bazel_brb/967240a6aae7d353a221d73f4375e038/execroot/__main__/bazel-out/k8-fastbuild/testlogs/test/syscalls/getdents_test_runsc_ptrace/test.log
//test/syscalls:getdents_test_runsc_ptrace_overlay FAILED in 4.9s
/usr/local/google/home/brb/.cache/bazel/_bazel_brb/967240a6aae7d353a221d73f4375e038/execroot/__main__/bazel-out/k8-fastbuild/testlogs/test/syscalls/getdents_test_runsc_ptrace_overlay/test.log
//test/syscalls:getdents_test_runsc_ptrace_shared FAILED in 5.2s
/usr/local/google/home/brb/.cache/bazel/_bazel_brb/967240a6aae7d353a221d73f4375e038/execroot/__main__/bazel-out/k8-fastbuild/testlogs/test/syscalls/getdents_test_runsc_ptrace_shared/test.log
```
(I think all runsc_kvm tests are broken on my machine -- I'll rerun them
if you can point me at the documentation to set it up)
We don't have the plumbing for btime yet, so that field is left off. The
returned mask indicates that btime is absent.
Fixes#343
PiperOrigin-RevId: 254575752
Today we have the logic split in two places between endpoint Read() and the
worker goroutine which actually sends a zero window. This change makes it so
that when a zero window ACK is sent we set a flag in the endpoint which can be
read by the endpoint to decide if it should notify the worker to send a
nonZeroWindow update.
The worker now does not do the check again but instead sends an ACK and flips
the flag right away.
Similarly today when SO_RECVBUF is set the SetSockOpt call has logic
to decide if a zero window update is required. Rather than do that we move
the logic to the worker goroutine and it can check the zeroWindow flag
and send an update if required.
PiperOrigin-RevId: 254505447
Currently, the path tracking in the gofer involves an O(n) lookup of
child fidRefs. This causes a significant overhead on unlinks in
directories with lots of child fidRefs (<4k).
In this transition, pathNode moves from sync.Map to normal synchronized
maps. There is a small chance of contention in walk, but the lock is
held for a very short time (and sync.Map also had a chance of requiring
locking).
OTOH, sync.Map makes it very difficult to add a fidRef reverse map.
PiperOrigin-RevId: 254489952
Ian Lewis
Neel Natu
Andrei Vagin
gVisor bot
Yong He
Adin Scannell
Ayush Ranjan
Nicolas Lacasse
Ahmet Alp Balkan
Ian Gudger
Fabricio Voznika
Michael Pratt
Jamie Liu
Rahat Mahmood
brb-g
Bhasker Hariharan