Despite what the man page says, linux will return EINVAL when calling
getdents() an a /proc/[tid]/net file corresponding to a zombie task. This
causes readdir() to return a null pointer AND errno=EINVAL.
See fs/proc/proc_net.c:proc_tgid_net_readdir() for where this occurs.
We have tests that recursively read /proc, and are likely to hit this when
running natively, so we must catch and handle this case.
PiperOrigin-RevId: 317674168
The test was expecting that the root mount pathname was "/", but it doesn't
need to be. Only the mount point actually should be "/" (otherwise it is not
the root).
PiperOrigin-RevId: 316968025
There is the known issue of the linux procfs, that two consequent calls of
readdir can return the same entry twice if between these calls one or more
entries have been removed from this directory.
PiperOrigin-RevId: 309803066
Adds an oom_score_adj and oom_score proc file stub. oom_score_adj accepts
writes of values -1000 to 1000 and persists the value with the task. New tasks
inherit the parent's oom_score_adj.
oom_score is a read-only stub that always returns the value '0'.
Issue #202
PiperOrigin-RevId: 299245355
gVisor does not currently implement the functionality that would result in
AT_SECURE = 1, but Linux includes AT_SECURE = 0 in the normal case, so we
should do the same.
PiperOrigin-RevId: 272311488
TestNoDuplicates is racy as it tries to read the /proc file system
while the test is running. But it's possible that from the time a
directory entries are read and each entry processed something could
change and in some cases the entry being processed could have been
deleted. In such cases we should not fail the test but just
ignore the error and move on.
PiperOrigin-RevId: 267483094
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
Dean Deng
Ting-Yu Wang
Nicolas Lacasse
Andrei Vagin
Jamie Liu
Fabricio Voznika
Ian Lewis
Adin Scannell
gVisor bot
Haibo Xu
Bin Lu
Zach Koopmans
Michael Pratt
Bhasker Hariharan
chris.zn