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
Readdir of /proc/x/task/ will get direntry entries
from tasks of specified taskgroup. Now the tasks
slice is unsorted, use sort.SearchInts search entry
from the slice may cause infinity loops.
The fix is sort the slice before search.
This issue could be easily reproduced via following
steps, revise Readdir in pkg/sentry/fs/proc/task.go,
force set taskInts into test slice
[]int{1, 11, 7, 5, 10, 6, 8, 3, 9, 2, 4},
then run docker image and run ls /proc/1/task, the
command will cause infinity loops.
There will be a deadloop when we use getdents to read /proc/{pid}/task
of an exited process
Like this:
Process A is running
Process B: open /proc/{pid of A}/task
Process A exits
Process B: getdents /proc/{pid of A}/task
Then, process B will fall into deadloop, and return "." and ".."
in loops and never ends.
This patch returns ENOENT when use getdents to read /proc/{pid}/task
if the process is just exited.
Signed-off-by: chris.zn <chris.zn@antfin.com>
We don't actually support core dumps, but some applications want to
get/set dumpability, which still has an effect in procfs.
Lack of support for set-uid binaries or fs creds simplifies things a
bit.
As-is, processes started via CreateProcess (i.e., init and sentryctl
exec) have normal dumpability. I'm a bit torn on whether sentryctl exec
tasks should be dumpable, but at least since they have no parent normal
UID/GID checks should protect them.
PiperOrigin-RevId: 251712714
VmData is the size of private data segments.
It has the same meaning as in Linux.
Change-Id: Iebf1ae85940a810524a6cde9c2e767d4233ddb2a
PiperOrigin-RevId: 250593739
This does not actually implement an efficient splice or sendfile. Rather, it
adds a generic plumbing to the file internals so that this can be added. All
file implementations use the stub fileutil.NoSplice implementation, which
causes sendfile and splice to fall back to an internal copy.
A basic splice system call interface is added, along with a test.
PiperOrigin-RevId: 249335960
Change-Id: Ic5568be2af0a505c19e7aec66d5af2480ab0939b
Based on the guidelines at
https://opensource.google.com/docs/releasing/authors/.
1. $ rg -l "Google LLC" | xargs sed -i 's/Google LLC.*/The gVisor Authors./'
2. Manual fixup of "Google Inc" references.
3. Add AUTHORS file. Authors may request to be added to this file.
4. Point netstack AUTHORS to gVisor AUTHORS. Drop CONTRIBUTORS.
Fixes#209
PiperOrigin-RevId: 245823212
Change-Id: I64530b24ad021a7d683137459cafc510f5ee1de9
RootFromContext can return a dirent with reference taken, or nil. We must call
DecRef if (and only if) a real dirent is returned.
PiperOrigin-RevId: 242965515
Change-Id: Ie2b7b4cb19ee09b6ccf788b71f3fd7efcdf35a11
The start time is the number of clock ticks between the boot time and
application start time.
PiperOrigin-RevId: 240619475
Change-Id: Ic8bd7a73e36627ed563988864b0c551c052492a5
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
Create syscall stubs for missing syscalls upto Linux 4.4 and advertise
a kernel version of 4.4.
PiperOrigin-RevId: 220667680
Change-Id: Idbdccde538faabf16debc22f492dd053a8af0ba7
Zach Koopmans
gVisor bot
Adin Scannell
Yong He
chris.zn
Ian Gudger
Michael Pratt
chris.zn
Nicolas Lacasse
Jamie Liu
Zhaozhong Ni
Rahat Mahmood
Googler