IPTables.connections contains a sync.RWMutex. Copying it will trigger copylocks
analysis. Tested by manually enabling nogo tests.
sync.RWMutex is added to IPTables for the additional race condition discovered.
PiperOrigin-RevId: 314817019
- Add /tmp handling
- Apply mount options
- Enable more container_test tests
- Forward signals to child process when test respaws process
to run as root inside namespace.
Updates #1487
PiperOrigin-RevId: 314263281
Using tee instead of read to detect when a O_RDONLY|O_NONBLOCK pipe FD has a
writer circumvents the problem of what to do with the byte read from the pipe,
avoiding much of the complexity of the fdpipe package.
PiperOrigin-RevId: 314216146
SetTraceback("all") does not include all goroutines in panics (you didn't think
it was that simple, did you?). It includes all _user_ goroutines; those started
by the runtime (such as GC workers) are excluded.
Switch to "system" to additionally include runtime goroutines, which are useful
to track down bugs in the runtime itself.
PiperOrigin-RevId: 314204473
* Aggregate architecture Overview in "What is gVisor?" as it makes more sense
in one place.
* Drop "user-space kernel" and use "application kernel". The term "user-space
kernel" is confusing when some platform implementation do not run in
user-space (instead running in guest ring zero).
* Clear up the relationship between the Platform page in the user guide and the
Platform page in the architecture guide, and ensure they are cross-linked.
* Restore the call-to-action quick start link in the main page, and drop the
GitHub link (which also appears in the top-right).
* Improve image formatting by centering all doc and blog images, and move the
image captions to the alt text.
PiperOrigin-RevId: 311845158
Linux 4.18 and later make reads and writes coherent between pre-copy-up and
post-copy-up FDs representing the same file on an overlay filesystem. However,
memory mappings remain incoherent:
- Documentation/filesystems/overlayfs.rst, "Non-standard behavior": "If a file
residing on a lower layer is opened for read-only and then memory mapped with
MAP_SHARED, then subsequent changes to the file are not reflected in the
memory mapping."
- fs/overlay/file.c:ovl_mmap() passes through to the underlying FD without any
management of coherence in the overlay.
- Experimentally on Linux 5.2:
```
$ cat mmap_cat_page.c
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <sys/mman.h>
#include <unistd.h>
int main(int argc, char **argv) {
if (argc < 2) {
errx(1, "syntax: %s [FILE]", argv[0]);
}
const int fd = open(argv[1], O_RDONLY);
if (fd < 0) {
err(1, "open(%s)", argv[1]);
}
const size_t page_size = sysconf(_SC_PAGE_SIZE);
void* page = mmap(NULL, page_size, PROT_READ, MAP_SHARED, fd, 0);
if (page == MAP_FAILED) {
err(1, "mmap");
}
for (;;) {
write(1, page, strnlen(page, page_size));
if (getc(stdin) == EOF) {
break;
}
}
return 0;
}
$ gcc -O2 -o mmap_cat_page mmap_cat_page.c
$ mkdir lowerdir upperdir workdir overlaydir
$ echo old > lowerdir/file
$ sudo mount -t overlay -o "lowerdir=lowerdir,upperdir=upperdir,workdir=workdir" none overlaydir
$ ./mmap_cat_page overlaydir/file
old
^Z
[1]+ Stopped ./mmap_cat_page overlaydir/file
$ echo new > overlaydir/file
$ cat overlaydir/file
new
$ fg
./mmap_cat_page overlaydir/file
old
```
Therefore, while the VFS1 gofer client's behavior of reopening read FDs is only
necessary pre-4.18, replacing existing memory mappings (in both sentry and
application address spaces) with mappings of the new FD is required regardless
of kernel version, and this latter behavior is common to both VFS1 and VFS2.
Re-document accordingly, and change the runsc flag to enabled by default.
New test:
- Before this CL: https://source.cloud.google.com/results/invocations/5b222d2c-e918-4bae-afc4-407f5bac509b
- After this CL: https://source.cloud.google.com/results/invocations/f28c747e-d89c-4d8c-a461-602b33e71aab
PiperOrigin-RevId: 311361267
Some code paths needed these syscalls anyways, so they should be included in
the filters. Given that we depend on these syscalls in some cases, there's no
real reason to avoid them any more.
PiperOrigin-RevId: 310829126
Synthetic sockets do not have the race condition issue in VFS2, and we will
get rid of privateunixsocket as well.
Fixes#1200.
PiperOrigin-RevId: 310386474
We can register any number of tables with any number of architectures, and
need not limit the definitions to the architecture in question. This allows
runsc to generate documentation for all architectures simultaneously.
Similarly, this simplifies the VFSv2 patching process.
PiperOrigin-RevId: 310224827
Previously we unconditionally failed to cleanup the networking files
(hostname, resolve.conf, hosts), and failed to cleanup the netns, etc on
partial setup failure.
We can drop the iptables commands from cleanup, as the routes
automatically go away when the device is deleted. Those commands were
failing previously.
Forward signals to the container, allowing it to exit normally when a
signal is received, and then for runsc to run the cleanup. This doesn't
cover cleanup when runsc is signalled before the container start, it
covers the most common case.
Fixes#2539Fixes#2540
Several tests are passing after getting TestAppExitStatus (run /bin/true)
changes. Make versions that run via VFS2 so that we know what is and isn't
working.
In addition, fix bug in VFSFile ReadFull. For the TestExePath test in
container_test.go, the case "unmasked" will return 0 bytes read with no
EOF err, causing the ReadFull call to spin.
PiperOrigin-RevId: 308428126
This change includes:
- Modifications to loader_test.go to get TestCreateMountNamespace to
pass with VFS2.
- Changes necessary to get TestHelloWorld in image tests to pass with
VFS2. This means runsc can run the hello-world container with docker
on VSF2.
Note: Containers that use sockets will not run with these changes.
See "//test/image/...". Any tests here with sockets currently fail
(which is all of them but HelloWorld).
PiperOrigin-RevId: 308363072
This is needed to set up host fds passed through a Unix socket. Note that
the host package depends on kernel, so we cannot set up the hostfs mount
directly in Kernel.Init as we do for sockfs and pipefs.
Also, adjust sockfs to make its setup look more like hostfs's and pipefs's.
PiperOrigin-RevId: 308274053
This change adds a layer of abstraction around the internal Docker APIs,
and eliminates all direct dependencies on Dockerfiles in the infrastructure.
A subsequent change will automated the generation of local images (with
efficient caching). Note that this change drops the use of bazel container
rules, as that experiment does not seem to be viable.
PiperOrigin-RevId: 308095430
This change renames the tools/images directory to tools/vm for clarity, and
adds a functional vm_test. Sharding is also added to the same test, and some
documentation added around key flags & variables to describe how they work.
Subsequent changes will add vm_tests for other cases, such as the runtime tests.
PiperOrigin-RevId: 307492245
Included:
- loader_test.go RunTest and TestStartSignal VFS2
- container_test.go TestAppExitStatus on VFS2
- experimental flag added to runsc to turn on VFS2
Note: shared mounts are not yet supported.
PiperOrigin-RevId: 307070753
Ting-Yu Wang
Fabricio Voznika
Jamie Liu
Michael Pratt
Nicolas Lacasse
gVisor bot
Mikael Mello
Adin Scannell
Bhasker Hariharan
Dean Deng
kevin.xu
moricho
Zach Koopmans
Andrei Vagin