Fixes#9932.
When Go is able to detect `io.Copy()` from a TCP socket or `AF_UNIX` stream
socket to a TCP socket, it attempts to implement the copy as a `splice(2)` from
the source to a pipe, followed by a `splice(2)` from the pipe to the
destination [1] (since `splice(2)` requires that one of the endpoints be a
pipe); the size of the pipe is set to 1 MB [2] (from a default of 64 KB [3]) to
reduce the number of splice syscalls required. In gVisor, a bug causes each
splice syscall from pipe to TCP socket to repeatedly read the *first* 64 KB [4]
of the pipe's data (when it contains more than 64 KB of data) rather than
*successive* chunks of 64 KB.
To fix this, advance pipe state by calling `Pipe.consumeLocked()` immediately
after `Pipe.peekLocked()`. Also defensively check that such FDs call
`Pipe.(usermem.IO)` methods on sequential addresses, and change
`fuse.deviceFD.Write()` to have this property.
[1] Go: `net/tcpsock_posix.go:TCPConn.readFrom()` =>
`net/splice_linux.go:splice()` => `internal/poll/splice_linux.go:Splice()`
[2] Go: `internal/poll/splice_linux.go:newPipe()` => `maxSpliceSize`
[3] `pkg/kernel/pipe/pipe.go:DefaultPipeSize`
[4] `pkg/tcpip/transport/tcp/endpoint.go:endpoint.Write()` =>
`endpoint.queueSegment()` => `endpoint.readFromPayloader()` =>
`pkg/buffer/buffer.go:Buffer.WriteFromReader()` =>
`pkg/buffer/chunk.go:MaxChunkSize`
PiperOrigin-RevId: 603151951
This CL does the following:
- Add the ability for nested locks to have names.
- Give names to all current uses of nested locks in the codebase.
- Truncate `lockdep` debug stack traces to avoid the clutter from the
`lockdep` code itself
- Simplify `lockdep` to not longer require `classMap`.
PiperOrigin-RevId: 491486620
This change adapts the existing context to use more suitable non-channel-based
methods. This is a requisite for migrating the kernel internals to a
sleeper-based notification mechanism.
The last uses of amutex outside those migrated as part of this change were
dropped in a previous change. Since amutex depends on the channel-based
implementation, this package is also deleted as part of this change.
PiperOrigin-RevId: 415189675
Removes package syserror and moves still relevant code to either linuxerr
or to syserr (to be later removed).
Internal errors are converted from random types to *errors.Error types used
in linuxerr. Internal errors are in linuxerr/internal.go.
PiperOrigin-RevId: 390724202
Remove three syserror entries duplicated in linuxerr. Because of the
linuxerr.Equals method, this is a mere change of return values from
syserror to linuxerr definitions.
Done with only these three errnos as CLs removing all grow to a significantly
large size.
PiperOrigin-RevId: 382173835
Add Equals method to compare syserror and unix.Errno errors to linuxerr errors.
This will facilitate removal of syserror definitions in a followup, and
finding needed conversions from unix.Errno to linuxerr.
PiperOrigin-RevId: 380909667
Split usermem package to help remove syserror dependency in go_marshal.
New hostarch package contains code not dependent on syserror.
PiperOrigin-RevId: 365651233
The syscall package has been deprecated in favor of golang.org/x/sys.
Note that syscall is still used in the following places:
- pkg/sentry/socket/hostinet/stack.go: some netlink related functionalities
are not yet available in golang.org/x/sys.
- syscall.Stat_t is still used in some places because os.FileInfo.Sys() still
returns it and not unix.Stat_t.
Updates #214
PiperOrigin-RevId: 360701387
- Remove the pipe package's dependence on the buffer package, which becomes
unused as a result. The buffer package is currently intended to serve two use
cases, pipes and temporary buffers, and does neither optimally as a result;
this change facilitates retooling the buffer package to better serve the
latter.
- Pass callbacks taking safemem.BlockSeq to the internal pipe I/O methods,
which makes most callbacks trivial.
- Fix VFS1's splice() and tee() to immediately return if a pipe returns a
partial write.
PiperOrigin-RevId: 351911375
- 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
- Change FileDescriptionImpl Lock/UnlockPOSIX signature to
take {start,length,whence}, so the correct offset can be
calculated in the implementations.
- Create PosixLocker interface to make it possible to share
the same locking code from different implementations.
Closes#1480
PiperOrigin-RevId: 316910286
LockFD is the generic implementation that can be embedded in
FileDescriptionImpl implementations. Unique lock ID is
maintained in vfs.FileDescription and is created on demand.
Updates #1480
PiperOrigin-RevId: 315604825
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
* 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
* Pulls common functionality (IO and locking on open) into pipe_util.go.
* Adds pipe/vfs.go, which implements a subset of vfs.FileDescriptionImpl.
A subsequent change will add support for pipes in memfs.
PiperOrigin-RevId: 275322385
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