MM.insertPMAsLocked() passes vma.maxPerms to memmap.Mappable.Translate
(although it unsets AccessType.Write if the vma is private). This
somewhat simplifies handling of pmas, since it means only COW-break
needs to replace existing pmas. However, it also means that a MAP_SHARED
mapping of a file opened O_RDWR dirties the file, regardless of the
mapping's permissions and whether or not the mapping is ever actually
written to with I/O that ignores permissions (e.g.
ptrace(PTRACE_POKEDATA)).
To fix this:
- Change the pma-getting path to request only the permissions that are
required for the calling access.
- Change memmap.Mappable.Translate to take requested permissions, and
return allowed permissions. This preserves the existing behavior in the
common cases where the memmap.Mappable isn't
fsutil.CachingInodeOperations and doesn't care if the translated
platform.File pages are written to.
- Change the MM.getPMAsLocked path to support permission upgrading of
pmas outside of copy-on-write.
PiperOrigin-RevId: 240196979
Change-Id: Ie0147c62c1fbc409467a6fa16269a413f3d7d571
ilist:generic_list works faster than ilist:ilist.
Here is a beanchmark test to measure performance of epoll_wait, when readyList
isn't empty. It shows about 30% better performance with these changes.
Benchmark Time(ns) CPU(ns) Iterations
Before:
BM_EpollAllEvents 46725 46899 14286
After:
BM_EpollAllEvents 33167 33300 18919
PiperOrigin-RevId: 240185278
Change-Id: I3e33f9b214db13ab840b91613400525de5b58d18
Change the DPL from 0 to 3 for Breakpoint and Overflow,
then user space could trigger Breakpoint and Overflow
as excepected.
Change-Id: Ibead65fb8c98b32b7737f316db93b3a8d9dcd648
PiperOrigin-RevId: 239736648
Also, changing queue.writeBuf from a buffer.Bytes to a [][]byte should reduce
copying and reallocating of slices.
PiperOrigin-RevId: 239713547
Change-Id: I6ee5ff19c3ee2662f1af5749cae7b73db0569e96
.net sets these flags to -1 and then uses their result, especting it to be
zero.
Does not set actual flags (e.g. MSG_TRUNC), but setting to zero is more correct
than what we did before.
PiperOrigin-RevId: 239657951
Change-Id: I89c5f84bc9b94a2cd8ff84e8ecfea09e01142030
A credential object is immutable, so we don't need to copy it for a new
task.
PiperOrigin-RevId: 239519266
Change-Id: I0632f641fdea9554779ac25d84bee4231d0d18f2
Track new sockets created during accept(2) in the socket table for all
families. Previously we were only doing this for unix domain sockets.
PiperOrigin-RevId: 239475550
Change-Id: I16f009f24a06245bfd1d72ffd2175200f837c6ac
In the case of a rename replacing an existing destination inode, ramfs
Rename failed to first remove the replaced inode. This caused:
1. A leak of a reference to the inode (making it live indefinitely).
2. For directories, a leak of the replaced directory's .. link to the
parent. This would cause the parent's link count to incorrectly
increase.
(2) is much simpler to test than (1), so that's what I've done.
agentfs has a similar bug with link count only, so the Dirent layer
informs the Inode if this is a replacing rename.
Fixes#133
PiperOrigin-RevId: 239105698
Change-Id: I4450af2462d8ae3339def812287213d2cbeebde0
This is in preparation for improved page cache reclaim, which requires
greater integration between the page cache and page allocator.
PiperOrigin-RevId: 238444706
Change-Id: Id24141b3678d96c7d7dc24baddd9be555bffafe4
p9.Twalk.handle() with a non-empty path also stats the walked-to path
anyway, so the preceding GetAttr is completely wasted.
PiperOrigin-RevId: 238440645
Change-Id: I7fbc7536f46b8157639d0d1f491e6aaa9ab688a3
- Redefine some memmap.Mappable, platform.File, and platform.Memory
semantics in terms of File reference counts (no functional change).
- Make AddressSpace.MapFile take a platform.File instead of a raw FD,
and replace platform.File.MapInto with platform.File.FD. This allows
kvm.AddressSpace.MapFile to always use platform.File.MapInternal instead
of maintaining its own (redundant) cache of file mappings in the sentry
address space.
PiperOrigin-RevId: 238044504
Change-Id: Ib73a11e4275c0da0126d0194aa6c6017a9cef64f
getsockopt(IP_MULTICAST_IF) only supports struct in_addr.
Also adds support for setsockopt(IP_MULTICAST_IF) with struct in_addr.
PiperOrigin-RevId: 237620230
Change-Id: I75e7b5b3e08972164eb1906f43ddd67aedffc27c
IP_MULTICAST_LOOP controls whether or not multicast packets sent on the default
route are looped back. In order to implement this switch, support for sending
and looping back multicast packets on the default route had to be implemented.
For now we only support IPv4 multicast.
PiperOrigin-RevId: 237534603
Change-Id: I490ac7ff8e8ebef417c7eb049a919c29d156ac1c
It is Implemented without the priority inheritance part given
that gVisor defers scheduling decisions to Go runtime and doesn't
have control over it.
PiperOrigin-RevId: 236989545
Change-Id: I714c8ca0798743ecf3167b14ffeb5cd834302560
The globalPool uses a sync.Once mechanism for initialization,
and no cleanup is strictly required. It's not really feasible
to have the platform implement a full creation -> destruction
cycle (due to the way filters are assumed to be installed), so
drop the FIXME.
PiperOrigin-RevId: 236385278
Change-Id: I98ac660ed58cc688d8a07147d16074a3e8181314
Current procfs has some bugs. After executing ls twice, many dirs come
out with same name like "1" or ".". Files like "cpuinfo" disappear.
Here variable names is a slice with cap() > len(). Sort after appending
to it will not alloc a new space and impact orignal slice. Same to m.
Signed-off-by: Ruidong Cao <crdfrank@gmail.com>
Change-Id: I83e5cd1c7968c6fe28c35ea4fee497488d4f9eef
PiperOrigin-RevId: 236222270
Broadly, this change:
* Enables sockets to be created via `socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)`.
* Passes the network-layer (IP) header up the stack to the transport endpoint,
which can pass it up to the socket layer. This allows a raw socket to return
the entire IP packet to users.
* Adds functions to stack.TransportProtocol, stack.Stack, stack.transportDemuxer
that enable incoming packets to be delivered to raw endpoints. New raw sockets
of other protocols (not ICMP) just need to register with the stack.
* Enables ping.endpoint to return IP headers when created via SOCK_RAW.
PiperOrigin-RevId: 235993280
Change-Id: I60ed994f5ff18b2cbd79f063a7fdf15d093d845a
This change adds support for the SO_BROADCAST socket option in gVisor Netstack.
This support includes getsockopt()/setsockopt() functionality for both UDP and
TCP endpoints (the latter being a NOOP), dispatching broadcast messages up and
down the stack, and route finding/creation for broadcast packets. Finally, a
suite of tests have been implemented, exercising this functionality through the
Linux syscall API.
PiperOrigin-RevId: 234850781
Change-Id: If3e666666917d39f55083741c78314a06defb26c
- Use new user namespace for namespace creation checks.
- Ensure userns is never nil since it's used by other namespaces.
PiperOrigin-RevId: 234673175
Change-Id: I4b9d9d1e63ce4e24362089793961a996f7540cd9
In addition to simplifying the implementation, this fixes two bugs:
- seqfile.NewSeqFile unconditionally creates an inode with mode 0444,
but {uid,gid}_map have mode 0644.
- idMapSeqFile.Write implements fs.FileOperations.Write ... but it
doesn't implement any other fs.FileOperations methods and is never
used as fs.FileOperations. idMapSeqFile.GetFile() =>
seqfile.SeqFile.GetFile() uses seqfile.seqFileOperations instead,
which rejects all writes.
PiperOrigin-RevId: 234638212
Change-Id: I4568f741ab07929273a009d7e468c8205a8541bc
This allows setting a default send interface for IPv4 multicast. IPv6 support
will come later.
PiperOrigin-RevId: 234251379
Change-Id: I65922341cd8b8880f690fae3eeb7ddfa47c8c173
SO_TIMESTAMP is reimplemented in ping and UDP sockets (and needs to be added for
TCP), but can just be implemented in epsocket for simplicity. This will also
make SIOCGSTAMP easier to implement.
PiperOrigin-RevId: 234179300
Change-Id: Ib5ea0b1261dc218c1a8b15a65775de0050fe3230
If a background process tries to read from a TTY, linux sends it a SIGTTIN
unless the signal is blocked or ignored, or the process group is an orphan, in
which case the syscall returns EIO.
See drivers/tty/n_tty.c:n_tty_read()=>job_control().
If a background process tries to write a TTY, set the termios, or set the
foreground process group, linux then sends a SIGTTOU. If the signal is ignored
or blocked, linux allows the write. If the process group is an orphan, the
syscall returns EIO.
See drivers/tty/tty_io.c:tty_check_change().
PiperOrigin-RevId: 234044367
Change-Id: I009461352ac4f3f11c5d42c43ac36bb0caa580f9
- Fix CopyIn/CopyOut/ZeroOut range checks.
- Include the faulting signal number in the panic message.
PiperOrigin-RevId: 233829501
Change-Id: I8959ead12d05dbd4cd63c2b908cddeb2a27eb513
fs/gofer/inodeOperations.Release does some asynchronous work. Previously it
was calling fs.Async with an anonymous function, which caused the function to
be allocated on the heap. Because Release is relatively hot, this results in a
lot of small allocations and increased GC pressure, noticeable in perf profiles.
This CL adds a new function, AsyncWithContext, which is just like Async, but
passes a context to the async function. It avoids the need for an extra
anonymous function in fs/gofer/inodeOperations.Release. The Async function
itself still requires a single anonymous function.
PiperOrigin-RevId: 233141763
Change-Id: I1dce4a883a7be9a8a5b884db01e654655f16d19c
CopyObjectOut grows its destination byte slice incrementally, causing
many small slice allocations on the heap. This leads to increased GC and
noticeably slower stat calls.
PiperOrigin-RevId: 233140904
Change-Id: Ieb90295dd8dd45b3e56506fef9d7f86c92e97d97
This adds an extra Reflection call to CopyObjectOut, but avoids many small
slice allocations if the object is large, since without this we grow the
backing slice incrementally as we encode more data.
PiperOrigin-RevId: 233110960
Change-Id: I93569af55912391e5471277f779139c23f040147
Also includes a few fixes for IPv4 multicast support. IPv6 support is coming in
a followup CL.
PiperOrigin-RevId: 233008638
Change-Id: If7dae6222fef43fda48033f0292af77832d95e82
It currently allocates a new context on the heap each time it is called. Some
of these are in relatively hot paths like signal delivery and releasing gofer
inodes. It is also called very commonly in afterLoad. All of these should
benefit from fewer heap allocations.
PiperOrigin-RevId: 232938873
Change-Id: I53cec0ca299f56dcd4866b0b4fd2ec4938526849
- Change proc to return envp on overwrite of argv with limitations from
upstream.
- Add unit tests
- Change layout of argv/envp on the stack so that end of argv is contiguous with
beginning of envp.
PiperOrigin-RevId: 232506107
Change-Id: I993880499ab2c1220f6dc456a922235c49304dec
Dirty should be set only when the attribute is changed in the cache
only. Instances where the change was also sent to the backing file
doesn't need to dirty the attribute.
Also remove size update during WriteOut as writing dirty page would
naturaly grow the file if needed.
RELNOTES: relnotes is needed for the parent CL.
PiperOrigin-RevId: 232068978
Change-Id: I00ba54693a2c7adc06efa9e030faf8f2e8e7f188
This changed required making fsutil.HostMappable use
a backing file to ensure the correct FD would be used
for read/write operations.
RELNOTES: relnotes is needed for the parent CL.
PiperOrigin-RevId: 231836164
Change-Id: I8ae9639715529874ea7d80a65e2c711a5b4ce254
Nothing reads them and they can simply get stale.
Generated with:
$ sed -i "s/licenses(\(.*\)).*/licenses(\1)/" **/BUILD
PiperOrigin-RevId: 231818945
Change-Id: Ibc3f9838546b7e94f13f217060d31f4ada9d4bf0
We were modifying InodeSimpleAttributes.Unstable.AccessTime without holding
the necessary lock. Luckily for us, InodeSimpleAttributes already has a
NotifyAccess method that will do the update while holding the lock.
In addition, we were holding dfo.dir.mu.Lock while setting AccessTime, which
is unnecessary, so that lock has been removed.
PiperOrigin-RevId: 231278447
Change-Id: I81ed6d3dbc0b18e3f90c1df5e5a9c06132761769
It never actually should have applied to environ (the relevant change in
Linux 4.2 is c2c0bb44620d "proc: fix PAGE_SIZE limit of
/proc/$PID/cmdline"), and we claim to be Linux 4.4 now anyway.
PiperOrigin-RevId: 231250661
Change-Id: I37f9c4280a533d1bcb3eebb7803373ac3c7b9f15
When file size changes outside the sandbox, page cache was not
refreshing file size which is required for cacheRemoteRevalidating.
In fact, cacheRemoteRevalidating should be skipping the cache
completely since it's not really benefiting from it. The cache is
cache is already bypassed for unstable attributes (see
cachePolicy.cacheUAttrs). And althought the cache is called to
map pages, they will always miss the cache and map directly from
the host.
Created a HostMappable struct that maps directly to the host and
use it for files with cacheRemoteRevalidating.
Closes#124
PiperOrigin-RevId: 230998440
Change-Id: Ic5f632eabe33b47241e05e98c95e9b2090ae08fc
Most of the entries are stubbed out at the moment, but even those were
only displayed if IPv6 support was enabled. The entries should be
displayed with IPv4-support only, and with only loopback devices.
PiperOrigin-RevId: 229946441
Change-Id: I18afaa3af386322787f91bf9d168ab66c01d5a4c
More helper structs have been added to the fsutil package to make it easier to
implement fs.InodeOperations and fs.FileOperations.
PiperOrigin-RevId: 229305982
Change-Id: Ib6f8d3862f4216745116857913dbfa351530223b
Removing check to RLIMIT_NOFILE in select call.
Adding unit test to select suite to document behavior.
Moving setrlimit class from mlock to a util file for reuse.
Fixing flaky test based on comments from Jamie.
PiperOrigin-RevId: 228726131
Change-Id: Ie9dbe970bbf835ba2cca6e17eec7c2ee6fadf459
- Call MemoryEvents.done.Add(1) outside of MemoryEvents.run() so that if
MemoryEvents.Stop() => MemoryEvents.done.Wait() is called before the
goroutine starts running, it still waits for the goroutine to stop.
- Use defer to call MemoryEvents.done.Done() in MemoryEvents.run() so that it's
called even if the goroutine panics.
PiperOrigin-RevId: 228623307
Change-Id: I1b0459e7999606c1a1a271b16092b1ca87005015
overlayFileOperations.Readdir was holding overlay.copyMu while calling
DirentReaddir, which then attempts to take take the corresponding Dirent.mu,
causing a lock order violation. (See lock order documentation in
fs/copy_up.go.)
We only actually need to hold copyMu during readdirEntries(), so holding the
lock is moved in there, thus avoiding the lock order violation.
A new lock was added to protect overlayFileOperations.dirCache. We were
inadvertently relying on copyMu to protect this. There is no reason it should
not have its own lock.
PiperOrigin-RevId: 228542473
Change-Id: I03c3a368c8cbc0b5a79d50cc486fc94adaddc1c2
See modified comment in auth.NewUserCredentials(); compare to the
behavior of setresuid(2) as implemented by
//pkg/sentry/kernel/task_identity.go:kernel.Task.setKUIDsUncheckedLocked().
PiperOrigin-RevId: 228381765
Change-Id: I45238777c8f63fcf41b99fce3969caaf682fe408
This option allows multiple sockets to be bound to the same port.
Incoming packets are distributed to sockets using a hash based on source and
destination addresses. This means that all packets from one sender will be
received by the same server socket.
PiperOrigin-RevId: 227153413
Change-Id: I59b6edda9c2209d5b8968671e9129adb675920cf
epoll_wait acquires EventPoll.listsMu (in EventPoll.ReadEvents) and
then calls Inotify.Readiness which tries to acquire Inotify.evMu.
getdents acquires Inotify.evMu (in Inotify.queueEvent) and then calls
readyCallback.Callback which tries to acquire EventPoll.listsMu.
The fix is to release Inotify.evMu before calling Queue.Notify. Queue
is thread-safe and doesn't require Inotify.evMu to be held.
Closes#121
PiperOrigin-RevId: 227066695
Change-Id: Id29364bb940d1727f33a5dff9a3c52f390c15761
We don't explicitly support out-of-band data and treat it like normal in-band
data. This is equilivent to SO_OOBINLINE being enabled, so always report that
it is enabled.
PiperOrigin-RevId: 226572742
Change-Id: I4c30ccb83265e76c30dea631cbf86822e6ee1c1b
Within gVisor, plumb new socket options to netstack.
Within netstack, fix GetSockOpt and SetSockOpt return value logic.
PiperOrigin-RevId: 226532229
Change-Id: If40734e119eed633335f40b4c26facbebc791c74
The code that matches the event being published with events watchers
was wronly matching all watchers in case any of the control event bits
were set.
Issue #121
PiperOrigin-RevId: 226521230
Change-Id: Ie2c42bc4366faaf59fbf80a74e9297499bd93f9e
We must wait for all lazy resources to be released before closing the rootFile.
PiperOrigin-RevId: 226419499
Change-Id: I1d4d961a92b3816e02690cf3eaf0a88944d730cc
"RLIMIT_MEMLOCK: This is the maximum number of bytes of memory that may
be locked into RAM." - getrlimit(2)
PiperOrigin-RevId: 226384346
Change-Id: Iefac4a1bb69f7714dc813b5b871226a8344dc800
Implement pwritev2 and associated unit tests.
Clean up preadv2 unit tests.
Tag RWF_ flags in both preadv2 and pwritev2 with associated bug tickets.
PiperOrigin-RevId: 226222119
Change-Id: Ieb22672418812894ba114bbc88e67f1dd50de620
Connectionless Unix sockets (DGRAM Unix sockets created with the socket system
call) inherently only have a read queue. They do not establish bidirectional
connections, instead, the connect system call only sets a default send
location. Writes give the data to the other endpoint which has its own read
queue.
To simplify the code, connectionless Unix sockets still get read and write
queues, but the write queue is a dummy and never waited on. The read queue is
the connectionless endpoint's queue. This change fixes a bug where the dummy
queue was incorrectly set as the read queue and the endpoint's queue was
incorrectly set as the write queue. This meant that read notifications went
to the dummy queue and were black holed.
PiperOrigin-RevId: 225921042
Change-Id: I8d9059def787a2c3c305185b92d05093fbd2be2a
The old overlayBoundEndpoint assumed that the lower is not an overlay. It
should check if the lower is an overlay and handle that case.
PiperOrigin-RevId: 225882303
Change-Id: I60660c587d91db2826e0719da0983ec8ad024cb8
Currently mlock() and friends do nothing whatsoever. However, mlocking
is directly application-visible in a number of ways; for example,
madvise(MADV_DONTNEED) and msync(MS_INVALIDATE) both fail on mlocked
regions. We handle this inconsistently: MADV_DONTNEED is too important
to not work, but MS_INVALIDATE is rejected.
Change MM to track mlocked regions in a manner consistent with Linux.
It still will not actually pin pages into host physical memory, but:
- mlock() will now cause sentry memory management to precommit mlocked
pages.
- MADV_DONTNEED and MS_INVALIDATE will interact with mlocked pages as
described above.
PiperOrigin-RevId: 225861605
Change-Id: Iee187204979ac9a4d15d0e037c152c0902c8d0ee
Platform objects are not savable, storing references to them in
filesystem datastructures would cause save to fail if someone actually
passed in a Platform.
Current implementations work because everywhere a Platform is
expected, we currently pass in a Kernel object which embeds Platform
and thus satisfies the interface.
Eliminate this indirection and save pointers to Kernel directly.
PiperOrigin-RevId: 225288336
Change-Id: Ica399ff43f425e15bc150a0d7102196c3d54a2ab
unshare actually takes a subset of clone flags, but has no unique flags,
so formatting as clone flags is close enough.
PiperOrigin-RevId: 225082774
Change-Id: I5b580f18607c7785f323e37809094115520a17c0
MSG_WAITALL requests that recv family calls do not perform short reads. It only
has an effect for SOCK_STREAM sockets, other types ignore it.
PiperOrigin-RevId: 224918540
Change-Id: Id97fbf972f1f7cbd4e08eec0138f8cbdf1c94fe7
arch_prctl already verified that the new FS_BASE was canonical, but
Task.Clone did not. Centralize these checks in the arch packages.
Failure to validate could cause an error in PTRACE_SET_REGS when we try
to switch to the app.
PiperOrigin-RevId: 224862398
Change-Id: Iefe63b3f9aa6c4810326b8936e501be3ec407f14
Unlike FlagSet, order doesn't matter here, so it can simply be a map.
PiperOrigin-RevId: 224377910
Change-Id: I15810c698a7f02d8614bf09b59583ab73cba0514
By Walking before checking that the directory is writable and
executable, MayDelete may return the Walk error (e.g., ENOENT) which
would normally be masked by a permission error (EACCES).
PiperOrigin-RevId: 224222453
Change-Id: I108a7f730e6bdaa7f277eaddb776267c00805475
If sys_prctl is called with PR_SET_MM without CAP_SYS_RESOURCE,
the syscall should return failure with errno set to EPERM.
See: http://man7.org/linux/man-pages/man2/prctl.2.html
PiperOrigin-RevId: 224182874
Change-Id: I630d1dd44af8b444dd16e8e58a0764a0cf1ad9a3
FileOperations.Write should return ErrWouldBlock to allow the upper
layer to loop and sendmsg should continue writing where it left off
on a partial write.
PiperOrigin-RevId: 224081631
Change-Id: Ic61f6943ea6b7abbd82e4279decea215347eac48
The number of symbolic links that are allowed to be followed
are for a full path and not just a chain of symbolic links.
PiperOrigin-RevId: 224047321
Change-Id: I5e3c4caf66a93c17eeddcc7f046d1e8bb9434a40
Bazel runs multiple test cases on the same thread. Some of the test
cases rely on the test thread starting with the default memory policy,
while other tests modify the test thread's memory policy. This
obviously breaks when the test framework doesn't run each test case on
a new thread.
Also fixing an incompatibility where set_mempolicy(2) was prevented
from specifying an empty nodemask, which is allowed for some modes.
PiperOrigin-RevId: 224038957
Change-Id: Ibf780766f2706ebc9b129dbc8cf1b85c2a275074
Untyped integer constants default to type int and the binary package will panic
if one tries to encode an int.
PiperOrigin-RevId: 223890001
Change-Id: Iccc3afd6d74bad24c35d764508e450fd317b76ec
Replaces the WaitGroup with a RWMutex. Calls to Async hold the mutex for
reading, while AsyncBarrier takes the lock for writing. This ensures that all
executing Async work finishes before AsyncBarrier returns.
Also pushes the Async() call from Inode.Release into
gofer/InodeOperations.Release(). This removes a recursive Async call which
should not have been allowed in the first place. The gofer Release call is the
slow one (since it may make RPCs to the gofer), so putting the Async call there
makes sense.
PiperOrigin-RevId: 223093067
Change-Id: I116da7b20fce5ebab8d99c2ab0f27db7c89d890e
With rpcinet if shutdown flags are not saved before making
the rpc a race is possible where blocked threads are woken
up before the flags have been persisted. This would mean
that threads can block indefinitely in a recvmsg after a
shutdown(SHUT_RD) has happened.
PiperOrigin-RevId: 223089783
Change-Id: If595e7add12aece54bcdf668ab64c570910d061a
RET_KILL_THREAD doesn't work well for Go because it will
kill only the offending thread and leave the process hanging.
RET_TRAP can be masked out and it's not guaranteed to kill
the process. RET_KILL_PROCESS is available since 4.14.
For older kernel, continue to use RET_TRAP as this is the
best option (likely to kill process, easy to debug).
PiperOrigin-RevId: 222357867
Change-Id: Icc1d7d731274b16c2125b7a1ba4f7883fbdb2cbd
SyncSyscallFiltersToThreadGroup and Task.TheadID() both acquired TaskSet RWLock
in R mode and could deadlock if a writer comes in between.
PiperOrigin-RevId: 222313551
Change-Id: I4221057d8d46fec544cbfa55765c9a284fe7ebfa
Also update test utilities for probing vsyscall support and add a
metric to see if vsyscalls are actually used in sandboxes.
PiperOrigin-RevId: 221698834
Change-Id: I57870ecc33ea8c864bd7437833f21aa1e8117477
Previously, TCP_NODELAY was always enabled and we would lie about it being
configurable. TCP_NODELAY is now disabled by default (to match Linux) in the
socket layer so that non-gVisor users don't automatically start using this
questionable optimization.
PiperOrigin-RevId: 221368472
Change-Id: Ib0240f66d94455081f4e0ca94f09d9338b2c1356
sync_file_range - sync a file segment with disk
In Linux, sync_file_range() accepts three flags:
SYNC_FILE_RANGE_WAIT_BEFORE
Wait upon write-out of all pages in the specified range that
have already been submitted to the device driver for write-out
before performing any write.
SYNC_FILE_RANGE_WRITE
Initiate write-out of all dirty pages in the specified range
which are not presently submitted write-out. Note that even
this may block if you attempt to write more than request queue
size.
SYNC_FILE_RANGE_WAIT_AFTER
Wait upon write-out of all pages in the range after performing
any write.
In this implementation:
SYNC_FILE_RANGE_WAIT_BEFORE without SYNC_FILE_RANGE_WAIT_AFTER isn't
supported right now.
SYNC_FILE_RANGE_WRITE is skipped. It should initiate write-out of all
dirty pages, but it doesn't wait, so it should be safe to do nothing
while nobody uses SYNC_FILE_RANGE_WAIT_BEFORE.
SYNC_FILE_RANGE_WAIT_AFTER is equal to fdatasync(). In Linux,
sync_file_range() doesn't writes out the file's meta-data, but
fdatasync() does if a file size is changed.
PiperOrigin-RevId: 220730840
Change-Id: Iae5dfb23c2c916967d67cf1a1ad32f25eb3f6286
Create syscall stubs for missing syscalls upto Linux 4.4 and advertise
a kernel version of 4.4.
PiperOrigin-RevId: 220667680
Change-Id: Idbdccde538faabf16debc22f492dd053a8af0ba7
Updated error messages so that it doesn't print full Go struct representations
when running a new container in a sandbox. For example, this occurs frequently
when commands are not found when doing a 'kubectl exec'.
PiperOrigin-RevId: 219729141
Change-Id: Ic3a7bc84cd7b2167f495d48a1da241d621d3ca09
Shm segments can be marked for lazy destruction via shmctl(IPC_RMID),
which destroys a segment once it is no longer attached to any
processes. We were unconditionally decrementing the segment refcount
on shmctl(IPC_RMID) which allowed a user to force a segment to be
destroyed by repeatedly calling shmctl(IPC_RMID), with outstanding
memory maps to the segment.
This is problematic because the memory released by a segment destroyed
this way can be reused by a different process while remaining
accessible by the process with outstanding maps to the segment.
PiperOrigin-RevId: 219713660
Change-Id: I443ab838322b4fb418ed87b2722c3413ead21845
https://github.com/containerd/containerd/blob/master/oci/spec.go#L206, the mode=755
didn't match the pattern modeRegexp = regexp.MustCompile("0[0-7][0-7][0-7]").
Closes#112
Signed-off-by: Juan <xionghuan.cn@gmail.com>
Change-Id: I469e0a68160a1278e34c9e1dbe4b7784c6f97e5a
PiperOrigin-RevId: 219672525
This reduces the number of floating point save/restore cycles required (since
we don't need to restore immediately following the switch, this always happens
in a known context) and allows the kernel hooks to capture state. This lets us
remove calls like "Current()".
PiperOrigin-RevId: 219552844
Change-Id: I7676fa2f6c18b9919718458aa888b832a7db8cab
Use private futexes for performance and to align with other runtime uses.
PiperOrigin-RevId: 219422634
Change-Id: Ief2af5e8302847ea6dc246e8d1ee4d64684ca9dd
Previously this code used the tcpip error space. Since it is no longer part of
netstack, it can use the sentry's error space (except for a few cases where
there is still some shared code. This reduces the number of error space
conversions required for hot Unix socket operations.
PiperOrigin-RevId: 218541611
Change-Id: I3d13047006a8245b5dfda73364d37b8a453784bb
Pseudoterminal job control signals are meant to be received and handled by the
sandbox process, but if the ptrace stubs are running in the same process group,
they will receive the signals as well and inject then into the sentry kernel.
This can result in duplicate signals being delivered (often to the wrong
process), or a sentry panic if the ptrace stub is inactive.
This CL makes the ptrace stub run in a new session.
PiperOrigin-RevId: 218536851
Change-Id: Ie593c5687439bbfbf690ada3b2197ea71ed60a0e
Attempting to create a zero-len shm segment causes a panic since we
try to allocate a zero-len filemem region. The existing code had a
guard to disallow this, but the check didn't encode the fact that
requesting a private segment implies a segment creation regardless of
whether IPC_CREAT is explicitly specified.
PiperOrigin-RevId: 218405743
Change-Id: I30aef1232b2125ebba50333a73352c2f907977da
This change also adds extensive testing to the p9 package via mocks. The sanity
checks and type checks are moved from the gofer into the core package, where
they can be more easily validated.
PiperOrigin-RevId: 218296768
Change-Id: I4fc3c326e7bf1e0e140a454cbacbcc6fd617ab55
This allows us to release messages in the queue when all users close.
PiperOrigin-RevId: 218033550
Change-Id: I2f6e87650fced87a3977e3b74c64775c7b885c1b
Added events for *ctl syscalls that may have multiple different commands.
For runsc, each syscall event is only logged once. For *ctl syscalls, use
the cmd as identifier, not only the syscall number.
PiperOrigin-RevId: 218015941
Change-Id: Ie3c19131ae36124861e9b492a7dbe1765d9e5e59
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
This queue only has a single user, so there is no need for it to use an
interface. Merging it into the same package as its sole user allows us to avoid
a circular dependency.
This simplifies the code and should slightly improve performance.
PiperOrigin-RevId: 217595889
Change-Id: Iabbd5164240b935f79933618c61581bc8dcd2822
Now containers run with "docker run -it" support control characters like ^C and
^Z.
This required refactoring our signal handling a bit. Signals delivered to the
"runsc boot" process are turned into loader.Signal calls with the appropriate
delivery mode. Previously they were always sent directly to PID 1.
PiperOrigin-RevId: 217566770
Change-Id: I5b7220d9a0f2b591a56335479454a200c6de8732
The existing logic is backwards and writes iov_len == 0 for a full write.
PiperOrigin-RevId: 217560377
Change-Id: I5a39c31bf0ba9063a8495993bfef58dc8ab7c5fa
* Integrate recvMsg and sendMsg functions into Recv and Send respectively as
they are no longer shared.
* Clean up partial read/write error handling code.
* Re-order code to make sense given that there is no longer a host.endpoint
type.
PiperOrigin-RevId: 217255072
Change-Id: Ib43fe9286452f813b8309d969be11f5fa40694cd
host.endpoint contained duplicated logic from the sockerpair implementation and
host.ConnectedEndpoint. Remove host.endpoint in favor of a
host.ConnectedEndpoint wrapped in a socketpair end.
PiperOrigin-RevId: 217240096
Change-Id: I4a3d51e3fe82bdf30e2d0152458b8499ab4c987c
- Change Dirent.Busy => Dirent.isMountPoint. The function body is unchanged,
and it is no longer exported.
- fs.MayDelete now checks that the victim is not the process root. This aligns
with Linux's namei.c:may_delete().
- Fix "is-ancestor" checks to actually compare all ancestors, not just the
parents.
- Fix handling of paths that end in dots, which are handled differently in
Rename vs. Unlink.
PiperOrigin-RevId: 217239274
Change-Id: I7a0eb768e70a1b2915017ce54f7f95cbf8edf1fb
This is a defense-in-depth measure. If the sentry is compromised, this prevents
system call injection to the stubs. There is some complexity with respect to
ptrace and seccomp interactions, so this protection is not really available
for kernel versions < 4.8; this is detected dynamically.
Note that this also solves the vsyscall emulation issue by adding in
appropriate trapping for those system calls. It does mean that a compromised
sentry could theoretically inject these into the stub (ignoring the trap and
resume, thereby allowing execution), but they are harmless.
PiperOrigin-RevId: 216647581
Change-Id: Id06c232cbac1f9489b1803ec97f83097fcba8eb8
Currently, in the face of FileMem fragmentation and a large sendmsg or
recvmsg call, host sockets may pass > 1024 iovecs to the host, which
will immediately cause the host to return EMSGSIZE.
When we detect this case, use a single intermediate buffer to pass to
the kernel, copying to/from the src/dst buffer.
To avoid creating unbounded intermediate buffers, enforce message size
checks and truncation w.r.t. the send buffer size. The same
functionality is added to netstack unix sockets for feature parity.
PiperOrigin-RevId: 216590198
Change-Id: I719a32e71c7b1098d5097f35e6daf7dd5190eff7
Also properly add padding after Procs in the linux.Sysinfo
structure. This will be implicitly padded to 64bits so we
need to do the same.
PiperOrigin-RevId: 216372907
Change-Id: I6eb6a27800da61d8f7b7b6e87bf0391a48fdb475
We accidentally set the wrong maximum. I've also added PATH_MAX and
NAME_MAX to the linux abi package.
PiperOrigin-RevId: 216221311
Change-Id: I44805fcf21508831809692184a0eba4cee469633
- Shared futex objects on shared mappings are represented by Mappable +
offset, analogous to Linux's use of inode + offset. Add type
futex.Key, and change the futex.Manager bucket API to use futex.Keys
instead of addresses.
- Extend the futex.Checker interface to be able to return Keys for
memory mappings. It returns Keys rather than just mappings because
whether the address or the target of the mapping is used in the Key
depends on whether the mapping is MAP_SHARED or MAP_PRIVATE; this
matters because using mapping target for a futex on a MAP_PRIVATE
mapping causes it to stop working across COW-breaking.
- futex.Manager.WaitComplete depends on atomic updates to
futex.Waiter.addr to determine when it has locked the right bucket,
which is much less straightforward for struct futex.Waiter.key. Switch
to an atomically-accessed futex.Waiter.bucket pointer.
- futex.Manager.Wake now needs to take a futex.Checker to resolve
addresses for shared futexes. CLONE_CHILD_CLEARTID requires the exit
path to perform a shared futex wakeup (Linux:
kernel/fork.c:mm_release() => sys_futex(tsk->clear_child_tid,
FUTEX_WAKE, ...)). This is a problem because futexChecker is in the
syscalls/linux package. Move it to kernel.
PiperOrigin-RevId: 216207039
Change-Id: I708d68e2d1f47e526d9afd95e7fed410c84afccf
Terminal support in runsc relies on host tty file descriptors that are imported
into the sandbox. Application tty ioctls are sent directly to the host fd.
However, those host tty ioctls are associated in the host kernel with a host
process (in this case runsc), and the host kernel intercepts job control
characters like ^C and send signals to the host process. Thus, typing ^C into a
"runsc exec" shell will send a SIGINT to the runsc process.
This change makes "runsc exec" handle all signals, and forward them into the
sandbox via the "ContainerSignal" urpc method. Since the "runsc exec" is
associated with a particular container process in the sandbox, the signal must
be associated with the same container process.
One big difficulty is that the signal should not necessarily be sent to the
sandbox process started by "exec", but instead must be sent to the foreground
process group for the tty. For example, we may exec "bash", and from bash call
"sleep 100". A ^C at this point should SIGINT sleep, not bash.
To handle this, tty files inside the sandbox must keep track of their
foreground process group, which is set/get via ioctls. When an incoming
ContainerSignal urpc comes in, we look up the foreground process group via the
tty file. Unfortunately, this means we have to expose and cache the tty file in
the Loader.
Note that "runsc exec" now handles signals properly, but "runs run" does not.
That will come in a later CL, as this one is complex enough already.
Example:
root@:/usr/local/apache2# sleep 100
^C
root@:/usr/local/apache2# sleep 100
^Z
[1]+ Stopped sleep 100
root@:/usr/local/apache2# fg
sleep 100
^C
root@:/usr/local/apache2#
PiperOrigin-RevId: 215334554
Change-Id: I53cdce39653027908510a5ba8d08c49f9cf24f39
There was a race where we checked task.Parent() != nil, and then later called
task.Parent() again, assuming that it is not nil. If the task is exiting, the
parent may have been set to nil in between the two calls, causing a panic.
This CL changes the code to only call task.Parent() once.
PiperOrigin-RevId: 215274456
Change-Id: Ib5a537312c917773265ec72016014f7bc59a5f59
host.endpoint already has the check, but it is missing from
host.ConnectedEndpoint.
PiperOrigin-RevId: 214962762
Change-Id: I88bb13a5c5871775e4e7bf2608433df8a3d348e6
Previously, if address resolution for UDP or Ping sockets required sending
packets using Write in Transport layer, Resolve would return ErrWouldBlock
and Write would return ErrNoLinkAddress. Meanwhile startAddressResolution
would run in background. Further calls to Write using same address would also
return ErrNoLinkAddress until resolution has been completed successfully.
Since Write is not allowed to block and System Calls need to be
interruptible in System Call layer, the caller to Write is responsible for
blocking upon return of ErrWouldBlock.
Now, when startAddressResolution is called a notification channel for
the completion of the address resolution is returned.
The channel will traverse up to the calling function of Write as well as
ErrNoLinkAddress. Once address resolution is complete (success or not) the
channel is closed. The caller would call Write again to send packets and
check if address resolution was compeleted successfully or not.
Fixesgoogle/gvisor#5
Change-Id: Idafaf31982bee1915ca084da39ae7bd468cebd93
PiperOrigin-RevId: 214962200
We already forward TCSETS and TCSETSW. TCSETSF is roughly equivalent but
discards pending input.
The filters were relaxed to allow host ioctls with TCSETSF argument.
This fixes programs like "passwd" that prevent user input from being displayed
on the terminal.
Before:
root@b8a0240fc836:/# passwd
Enter new UNIX password: 123
Retype new UNIX password: 123
passwd: password updated successfully
After:
root@ae6f5dabe402:/# passwd
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
PiperOrigin-RevId: 214869788
Change-Id: I31b4d1373c1388f7b51d0f2f45ce40aa8e8b0b58
In order to implement kill --all correctly, the Sentry needs
to track all tasks that belong to a given container. This change
introduces ContainerID to the task, that gets inherited by all
children. 'kill --all' then iterates over all tasks comparing the
ContainerID field to find all processes that need to be signalled.
PiperOrigin-RevId: 214841768
Change-Id: I693b2374be8692d88cc441ef13a0ae34abf73ac6
Old code was returning ID of the thread that created
the child process. It should be returning the ID of
the parent process instead.
PiperOrigin-RevId: 214720910
Change-Id: I95715c535bcf468ecf1ae771cccd04a4cd345b36
If we have an overlay file whose corresponding Dirent is frozen, then we should
not bother calling Readdir on the upper or lower files, since DirentReaddir
will calculate children based on the frozen Dirent tree.
A test was added that fails without this change.
PiperOrigin-RevId: 213531215
Change-Id: I4d6c98f1416541a476a34418f664ba58f936a81d
This makes `runsc wait` behave more like waitpid()/wait4() in that:
- Once a process has run to completion, you can wait on it and get its exit
code.
- Processes not waited on will consume memory (like a zombie process)
PiperOrigin-RevId: 213358916
Change-Id: I5b5eca41ce71eea68e447380df8c38361a4d1558
runApp.execute -> Task.SendSignal -> sendSignalLocked -> sendSignalTimerLocked
-> pendingSignals.enqueue assumes that it owns the arch.SignalInfo returned
from platform.Context.Switch.
On the other hand, ptrace.context.Switch assumes that it owns the returned
SignalInfo and can safely reuse it on the next call to Switch. The KVM platform
always returns a unique SignalInfo.
This becomes a problem when the returned signal is not immediately delivered,
allowing a future signal in Switch to change the previous pending SignalInfo.
This is noticeable in #38 when external SIGINTs are delivered from the PTY
slave FD. Note that the ptrace stubs are in the same process group as the
sentry, so they are eligible to receive the PTY signals. This should probably
change, but is not the only possible cause of this bug.
Updates #38
Original change by newmanwang <wcs1011@gmail.com>, updated by Michael Pratt
<mpratt@google.com>.
Change-Id: I5383840272309df70a29f67b25e8221f933622cd
PiperOrigin-RevId: 213071072
Linux permits hard-linking if the target is owned by the user OR the target has
Read+Write permission.
PiperOrigin-RevId: 213024613
Change-Id: If642066317b568b99084edd33ee4e8822ec9cbb3
The old kernel version, such as 4.4, only support 255 vcpus.
While gvisor is ran on these kernels, it could panic because the
vcpu id and vcpu number beyond max_vcpus.
Use ioctl(vmfd, _KVM_CHECK_EXTENSION, _KVM_CAP_MAX_VCPUS) to get max
vcpus number dynamically.
Change-Id: I50dd859a11b1c2cea854a8e27d4bf11a411aa45c
PiperOrigin-RevId: 212929704
Netstack needs to be portable, so this seems to be preferable to using raw
system calls.
PiperOrigin-RevId: 212917409
Change-Id: I7b2073e7db4b4bf75300717ca23aea4c15be944c
The contract in ExecArgs says that a reference on ExecArgs.Root must be held
for the lifetime of the struct, but the caller is free to drop the ref after
that.
As a result, proc.Exec must take an additional ref on Root when it constructs
the CreateProcessArgs, since that holds a pointer to Root as well. That ref is
dropped in CreateProcess.
PiperOrigin-RevId: 212828348
Change-Id: I7f44a612f337ff51a02b873b8a845d3119408707
This is different from the existing -pid-file flag, which saves a host pid.
PiperOrigin-RevId: 212713968
Change-Id: I2c486de8dd5cfd9b923fb0970165ef7c5fc597f0
We were previously openining the platform device (i.e. /dev/kvm) inside the
platfrom constructor (i.e. kvm.New). This requires that we have RW access to
the platform device when constructing the platform.
However, now that the runsc sandbox process runs as user "nobody", it is not
able to open the platform device.
This CL changes the kvm constructor to take the platform device FD, rather than
opening the device file itself. The device file is opened outside of the
sandbox and passed to the sandbox process.
PiperOrigin-RevId: 212505804
Change-Id: I427e1d9de5eb84c84f19d513356e1bb148a52910
We must use a context.Context with a Root Dirent that corresponds to the
container's chroot. Previously we were using the root context, which does not
have a chroot.
Getting the correct context required refactoring some of the path-lookup code.
We can't lookup the path without a context.Context, which requires
kernel.CreateProcArgs, which we only get inside control.Execute. So we have to
do the path lookup much later than we previously were.
PiperOrigin-RevId: 212064734
Change-Id: I84a5cfadacb21fd9c3ab9c393f7e308a40b9b537
This allows applications to verify they are running with gVisor. It
also helps debugging when running with a mix of container runtimes.
Closes#54
PiperOrigin-RevId: 212059457
Change-Id: I51d9595ee742b58c1f83f3902ab2e2ecbd5cedec
Before destroying the Kernel, we disable signal forwarding,
relinquishing control to the Go runtime. External signals that arrive
after disabling forwarding but before the sandbox exits thus may use
runtime.raise (i.e., tkill(2)) and violate the syscall filters.
Adjust forwardSignals to handle signals received after disabling
forwarding the same way they are handled before starting forwarding.
i.e., by implementing the standard Go runtime behavior using tgkill(2)
instead of tkill(2).
This also makes the stop callback block until forwarding actually stops.
This isn't required to avoid tkill(2) but is a saner interface.
PiperOrigin-RevId: 211995946
Change-Id: I3585841644409260eec23435cf65681ad41f5f03
It was always returning the MountNamespace root, which may be different from
the process Root if the process is in a chroot environment.
PiperOrigin-RevId: 211862181
Change-Id: I63bfeb610e2b0affa9fdbdd8147eba3c39014480
Furthermore, allow for the specification of an ElementMapper. This allows a
single "Element" type to exist on multiple inline lists, and work without
having to embed the entry type.
This is a requisite change for supporting a per-Inode list of Dirents.
PiperOrigin-RevId: 211467497
Change-Id: If2768999b43e03fdaecf8ed15f435fe37518d163
Task.creds can only be changed by the task's own set*id and execve
syscalls, and Task namespaces can only be changed by the task's own
unshare/setns syscalls.
PiperOrigin-RevId: 211156279
Change-Id: I94d57105d34e8739d964400995a8a5d76306b2a0
From //pkg/sentry/context/context.go:
// - It is *not safe* to retain a Context passed to a function beyond the scope
// of that function call.
Passing a stored kernel.Task as a context.Context to
fs.FileOwnerFromContext violates this requirement.
PiperOrigin-RevId: 211143021
Change-Id: I4c5b02bd941407be4c9cfdbcbdfe5a26acaec037
This allows us to call kernel.FDMap.DecRef without holding mutexes
cleanly.
PiperOrigin-RevId: 211139657
Change-Id: Ie59d5210fb9282e1950e2e40323df7264a01bcec
dirent.walk() takes renameMu, but is often called with renameMu already held,
which can lead to a deadlock.
Fix this by requiring renameMu to be held for reading when dirent.walk() is
called. This causes walks and existence checks to block while a rename
operation takes place, but that is what we were already trying to enforce by
taking renameMu in walk() anyways.
PiperOrigin-RevId: 210760780
Change-Id: Id61018e6e4adbeac53b9c1b3aa24ab77f75d8a54
dirent.go:Rename() walks to the file being replaced and defers
replaced.DecRef(). After the rename, the reference is dropped, triggering a
writeout and SettAttr call to the gofer. Because of lazyOpenForWrite, the gofer
opens the replaced file BY ITS OLD NAME and calls ftruncate on it.
This CL changes Remove to drop the reference on replaced (and thus trigger
writeout) before the actual rename call.
PiperOrigin-RevId: 210756097
Change-Id: I01ea09a5ee6c2e2d464560362f09943641638e0f
Weak references save / restore involves multiple interface indirection
and cause material latency overhead when there are lots of dirents, each
containing a weak reference map. The nil entries in the map should also
be purged.
PiperOrigin-RevId: 210593727
Change-Id: Ied6f4c3c0726fcc53a24b983d9b3a79121b6b758
This is to troubleshoot problems with a hung process that is
not responding to 'runsc debug --stack' command.
PiperOrigin-RevId: 210483513
Change-Id: I4377b210b4e51bc8a281ad34fd94f3df13d9187d
When revalidating a Dirent, if the inode id is the same, then we don't need to
throw away the entire Dirent. We can just update the unstable attributes in
place.
If the inode id has changed, then the remote file has been deleted or moved,
and we have no choice but to throw away the dirent we have a look up another.
In this case, we may still end up losing a mounted dirent that is a child of
the revalidated dirent. However, that seems appropriate here because the entire
mount point has been pulled out from underneath us.
Because gVisor's overlay is at the Inode level rather than the Dirent level, we
must pass the parent Inode and name along with the Inode that is being
revalidated.
PiperOrigin-RevId: 210431270
Change-Id: I705caef9c68900234972d5aac4ae3a78c61c7d42
Jamie Liu
Andrei Vagin
Nicolas Lacasse
Yong He
Kevin Krakauer
Ian Gudger
Rahat Mahmood
Fabricio Voznika
Michael Pratt
Adin Scannell
Bhasker Hariharan
Ruidong Cao
Googler
Haibo Xu
Amanda Tait
Zach Koopmans
Zhaozhong Ni
Adin Scannell
Brian Geffon
Christopher Koch
Ian Lewis
Juan
Sepehr Raissian
newmanwang
Chenggang