Added syscall annotations for unimplemented syscalls for later generation into
reference docs. Annotations are of the form:
@Syscall(<name>, <key:value>, ...)
Supported args and values are:
- arg: A syscall option. This entry only applies to the syscall when given this
option.
- support: Indicates support level
- UNIMPLEMENTED: Unimplemented (implies returns:ENOSYS)
- PARTIAL: Partial support. Details should be provided in note.
- FULL: Full support
- returns: Indicates a known return value. Values are
syscall errors. This is treated as a string so you can use something
like "returns:EPERM or ENOSYS".
- issue: A Github issue number.
- note: A note
Example:
// @Syscall(mmap, arg:MAP_PRIVATE, support:FULL, note:Private memory fully supported)
// @Syscall(mmap, arg:MAP_SHARED, support:UNIMPLEMENTED, issue:123, note:Shared memory not supported)
// @Syscall(setxattr, returns:ENOTSUP, note:Requires file system support)
Annotations should be placed as close to their implementation as possible
(preferrably as part of a supporting function's Godoc) and should be updated as
syscall support changes.
PiperOrigin-RevId: 241697482
Change-Id: I7a846135db124e1271dc5057d788cba82ca312d4
Memfds are simply anonymous tmpfs files with no associated
mounts. Also implementing file seals, which Linux only implements for
memfds at the moment.
PiperOrigin-RevId: 240450031
Change-Id: I31de78b950101ae8d7a13d0e93fe52d98ea06f2f
.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
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
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
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
Nothing reads them and they can simply get stale.
Generated with:
$ sed -i "s/licenses(\(.*\)).*/licenses(\1)/" **/BUILD
PiperOrigin-RevId: 231818945
Change-Id: Ibc3f9838546b7e94f13f217060d31f4ada9d4bf0
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
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
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
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
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
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
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
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
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
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
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
- 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
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
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
Currently the implementation matches the behavior of moving data
between two file descriptors. However, it does not implement this
through zero-copy movement. Thus, this code is a starting point
to build the more complex implementation.
PiperOrigin-RevId: 208284483
Change-Id: Ibde79520a3d50bc26aead7ad4f128d2be31db14e
Add support for the seccomp syscall and the flag SECCOMP_FILTER_FLAG_TSYNC.
PiperOrigin-RevId: 207101507
Change-Id: I5eb8ba9d5ef71b0e683930a6429182726dc23175
Currently, there is an attempt to print FD flags, but
they are not decoded into a number, so we see something like this:
/criu # cat /proc/self/fdinfo/0
flags: {%!o(bool=000false)}
Actually, fdinfo has to contain file flags.
Change-Id: Idcbb7db908067447eb9ae6f2c3cfb861f2be1a97
PiperOrigin-RevId: 206794498
We have been unnecessarily creating too many savable types implicitly.
PiperOrigin-RevId: 206334201
Change-Id: Idc5a3a14bfb7ee125c4f2bb2b1c53164e46f29a8
FIOASYNC and friends are used to send signals when a file is ready for IO.
This may or may not be needed by Nginx. While Nginx does use it, it is unclear
if the code that uses it has any effect.
PiperOrigin-RevId: 201550828
Change-Id: I7ba05a7db4eb2dfffde11e9bd9a35b65b98d7f50
Walking off the bottom of the sigaltstack, for example with recursive faults,
results in forced signal delivery, not resetting the stack or pushing signal
stack to whatever happens to lie below the signal stack.
PiperOrigin-RevId: 199856085
Change-Id: I0004d2523f0df35d18714de2685b3eaa147837e0
Kernel before 2.6.16 return EINVAL, but later return ESPIPE for this case.
Also change type of "length" from Uint(uint32) to Int64.
Because C header uses type "size_t" (unsigned long) or "off_t" (long) for length.
And it makes more sense to check length < 0 with Int64 because Uint cannot be negative.
Change-Id: Ifd7fea2dcded7577a30760558d0d31f479f074c4
PiperOrigin-RevId: 197616743
When the amount of data read is more than the amount written, sendfile would not
adjust 'in file' position and would resume from the wrong location.
Closes#33
PiperOrigin-RevId: 196731287
Change-Id: Ia219895dd765016ed9e571fd5b366963c99afb27
Ian Lewis
Jamie Liu
Nicolas Lacasse
Rahat Mahmood
Ian Gudger
Fabricio Voznika
Michael Pratt
Zach Koopmans
Brian Geffon
Googler
Adin Scannell
Andrei Vagin
Justine Olshan
Neel Natu
Zhaozhong Ni
Andrei Vagin
Chanwit Kaewkasi