selftests/proc: add PROCMAP_QUERY ioctl tests

Extend existing proc-pid-vm.c tests with PROCMAP_QUERY ioctl() API. Test
a few successful and negative cases, validating querying filtering and
exact v

selftests/proc: add PROCMAP_QUERY ioctl tests

Extend existing proc-pid-vm.c tests with PROCMAP_QUERY ioctl() API. Test
a few successful and negative cases, validating querying filtering and
exact vs next VMA logic works as expected.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Andrii Nakryiko <[email protected]>
Acked-by: Liam R. Howlett <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Mike Rapoport (IBM) <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

selftests: centralize -D_GNU_SOURCE= to CFLAGS in lib.mk

Centralize the _GNU_SOURCE definition to CFLAGS in lib.mk. Remove
redundant defines from Makefiles that import lib.mk. Convert any usage of

selftests: centralize -D_GNU_SOURCE= to CFLAGS in lib.mk

Centralize the _GNU_SOURCE definition to CFLAGS in lib.mk. Remove
redundant defines from Makefiles that import lib.mk. Convert any usage of
"#define _GNU_SOURCE 1" to "#define _GNU_SOURCE".

This uses the form "-D_GNU_SOURCE=", which is equivalent to
"#define _GNU_SOURCE".

Otherwise using "-D_GNU_SOURCE" is equivalent to "-D_GNU_SOURCE=1" and
"#define _GNU_SOURCE 1", which is less commonly seen in source code and
would require many changes in selftests to avoid redefinition warnings.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Edward Liaw <[email protected]>
Suggested-by: John Hubbard <[email protected]>
Acked-by: Shuah Khan <[email protected]>
Reviewed-by: Muhammad Usama Anjum <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: André Almeida <[email protected]>
Cc: Darren Hart <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Jarkko Sakkinen <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Kevin Tian <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Paolo Abeni <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Reinette Chatre <[email protected]>
Cc: Sean Christopherson <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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proc: test "Kthread:" field

/proc/${pid}/status got Kthread field recently.

Test that userspace program is not reported as kernel thread.

Test that kernel thread is reported as kernel thread.
Use

proc: test "Kthread:" field

/proc/${pid}/status got Kthread field recently.

Test that userspace program is not reported as kernel thread.

Test that kernel thread is reported as kernel thread.
Use kthreadd with pid 2 for this.

Link: https://lkml.kernel.org/r/818c4c41-8668-4566-97a9-7254abf819ee@p183
Signed-off-by: Alexey Dobriyan <[email protected]>
Cc: Chunguang Wu <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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proc: test how it holds up with mapping'less process

Create process without mappings and check

/proc/*/maps
/proc/*/numa_maps
/proc/*/smaps
/proc/*/smaps_rollup

They must be empty (excluding v

proc: test how it holds up with mapping'less process

Create process without mappings and check

/proc/*/maps
/proc/*/numa_maps
/proc/*/smaps
/proc/*/smaps_rollup

They must be empty (excluding vsyscall page) or full of zeroes.

Retroactively this test should've caught embarassing /proc/*/smaps_rollup
oops:

[17752.703567] BUG: kernel NULL pointer dereference, address: 0000000000000000
[17752.703580] #PF: supervisor read access in kernel mode
[17752.703583] #PF: error_code(0x0000) - not-present page
[17752.703587] PGD 0 P4D 0
[17752.703593] Oops: 0000 [#1] PREEMPT SMP PTI
[17752.703598] CPU: 0 PID: 60649 Comm: cat Tainted: G W 5.19.9-100.fc35.x86_64 #1
[17752.703603] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./X99 Extreme6/3.1, BIOS P3.30 08/05/2016
[17752.703607] RIP: 0010:show_smaps_rollup+0x159/0x2e0

Note 1:
ProtectionKey field in /proc/*/smaps is optional,
so check most of its contents, not everything.

Note 2:
due to the nature of this test, child process hardly can signal
its readiness (after unmapping everything!) to parent.
I feel like "sleep(1)" is justified.
If you know how to do it without sleep please tell me.

Note 3:
/proc/*/statm is not tested but can be.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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procfs: do not list TID 0 in /proc/<pid>/task

If a task exits concurrently, task_pid_nr_ns may return 0.

[[email protected]: coding style tweaks]
[[email protected]: test that /proc/*/tas

procfs: do not list TID 0 in /proc/<pid>/task

If a task exits concurrently, task_pid_nr_ns may return 0.

[[email protected]: coding style tweaks]
[[email protected]: test that /proc/*/task doesn't contain "0"]
Link: https://lkml.kernel.org/r/[email protected]

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Florian Weimer <[email protected]>
Signed-off-by: Alexey Dobriyan <[email protected]>
Acked-by: Christian Brauner <[email protected]>
Reviewed-by: Alexey Dobriyan <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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selftests: proc: test subset=pid

Test that /proc instance mounted with

mount -t proc -o subset=pid

contains only ".", "..", "self", "thread-self" and pid directories.

Note:
Currently "subset=pid

selftests: proc: test subset=pid

Test that /proc instance mounted with

mount -t proc -o subset=pid

contains only ".", "..", "self", "thread-self" and pid directories.

Note:
Currently "subset=pid" doesn't return "." and ".." via readdir.
This must be a bug.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Alexey Dobriyan <[email protected]>
Acked-by: Alexey Gladkov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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proc: use human-readable values for hidepid

The hidepid parameter values are becoming more and more and it becomes
difficult to remember what each new magic number means.

Backward compatibility is

proc: use human-readable values for hidepid

The hidepid parameter values are becoming more and more and it becomes
difficult to remember what each new magic number means.

Backward compatibility is preserved since it is possible to specify
numerical value for the hidepid parameter. This does not break the
fsconfig since it is not possible to specify a numerical value through
it. All numeric values are converted to a string. The type
FSCONFIG_SET_BINARY cannot be used to indicate a numerical value.

Selftest has been added to verify this behavior.

Suggested-by: Andy Lutomirski <[email protected]>
Signed-off-by: Alexey Gladkov <[email protected]>
Reviewed-by: Alexey Dobriyan <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Eric W. Biederman <[email protected]>

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proc: allow to mount many instances of proc in one pid namespace

This patch allows to have multiple procfs instances inside the
same pid namespace. The aim here is lightweight sandboxes, and to allo

proc: allow to mount many instances of proc in one pid namespace

This patch allows to have multiple procfs instances inside the
same pid namespace. The aim here is lightweight sandboxes, and to allow
that we have to modernize procfs internals.

1) The main aim of this work is to have on embedded systems one
supervisor for apps. Right now we have some lightweight sandbox support,
however if we create pid namespacess we have to manages all the
processes inside too, where our goal is to be able to run a bunch of
apps each one inside its own mount namespace without being able to
notice each other. We only want to use mount namespaces, and we want
procfs to behave more like a real mount point.

2) Linux Security Modules have multiple ptrace paths inside some
subsystems, however inside procfs, the implementation does not guarantee
that the ptrace() check which triggers the security_ptrace_check() hook
will always run. We have the 'hidepid' mount option that can be used to
force the ptrace_may_access() check inside has_pid_permissions() to run.
The problem is that 'hidepid' is per pid namespace and not attached to
the mount point, any remount or modification of 'hidepid' will propagate
to all other procfs mounts.

This also does not allow to support Yama LSM easily in desktop and user
sessions. Yama ptrace scope which restricts ptrace and some other
syscalls to be allowed only on inferiors, can be updated to have a
per-task context, where the context will be inherited during fork(),
clone() and preserved across execve(). If we support multiple private
procfs instances, then we may force the ptrace_may_access() on
/proc/<pids>/ to always run inside that new procfs instances. This will
allow to specifiy on user sessions if we should populate procfs with
pids that the user can ptrace or not.

By using Yama ptrace scope, some restricted users will only be able to see
inferiors inside /proc, they won't even be able to see their other
processes. Some software like Chromium, Firefox's crash handler, Wine
and others are already using Yama to restrict which processes can be
ptracable. With this change this will give the possibility to restrict
/proc/<pids>/ but more importantly this will give desktop users a
generic and usuable way to specifiy which users should see all processes
and which users can not.

Side notes:
* This covers the lack of seccomp where it is not able to parse
arguments, it is easy to install a seccomp filter on direct syscalls
that operate on pids, however /proc/<pid>/ is a Linux ABI using
filesystem syscalls. With this change LSMs should be able to analyze
open/read/write/close...

In the new patch set version I removed the 'newinstance' option
as suggested by Eric W. Biederman.

Selftest has been added to verify new behavior.

Signed-off-by: Alexey Gladkov <[email protected]>
Reviewed-by: Alexey Dobriyan <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Eric W. Biederman <[email protected]>

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proc: test /proc/sysvipc vs setns(CLONE_NEWIPC)

I thought that /proc/sysvipc has the same bug as /proc/net

commit 1fde6f21d90f8ba5da3cb9c54ca991ed72696c43
proc: fix /proc/net/* after setns(2)

Ho

proc: test /proc/sysvipc vs setns(CLONE_NEWIPC)

I thought that /proc/sysvipc has the same bug as /proc/net

commit 1fde6f21d90f8ba5da3cb9c54ca991ed72696c43
proc: fix /proc/net/* after setns(2)

However, it doesn't! /proc/sysvipc files do

get_ipc_ns(current->nsproxy->ipc_ns);

in their open() hook and avoid the problem.

Keep the test, maybe /proc/sysvipc will become broken someday :-\

Link: http://lkml.kernel.org/r/20190706180146.GA21015@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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proc: test /proc/*/maps, smaps, smaps_rollup, statm

Start testing VM related fiels found in per-process files.

Do it by jiting small executable which brings its address space to
precisely known sta

proc: test /proc/*/maps, smaps, smaps_rollup, statm

Start testing VM related fiels found in per-process files.

Do it by jiting small executable which brings its address space to
precisely known state, then comparing /proc/*/maps, smaps, smaps_rollup,
and statm files to expected values.

Currently only x86_64 is supported.

[[email protected]: exit correctly in /proc/*/maps test]
Link: http://lkml.kernel.org/r/20190206073659.GB15311@avx2
Link: http://lkml.kernel.org/r/20190203165806.GA14568@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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proc: fix /proc/net/* after setns(2)

/proc entries under /proc/net/* can't be cached into dcache because
setns(2) can change current net namespace.

[[email protected]: coding-style fixes]
[

proc: fix /proc/net/* after setns(2)

/proc entries under /proc/net/* can't be cached into dcache because
setns(2) can change current net namespace.

[[email protected]: coding-style fixes]
[[email protected]: avoid vim miscolorization]
[[email protected]: write test, add dummy ->d_revalidate hook: necessary if /proc/net/* is pinned at setns time]
Link: http://lkml.kernel.org/r/20190108192350.GA12034@avx2
Link: http://lkml.kernel.org/r/20190107162336.GA9239@avx2
Fixes: 1da4d377f943fe4194ffb9fb9c26cc58fad4dd24 ("proc: revalidate misc dentries")
Signed-off-by: Alexey Dobriyan <[email protected]>
Reported-by: Mateusz Stępień <[email protected]>
Reported-by: Ahmad Fatoum <[email protected]>
Cc: Al Viro <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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proc: test /proc/thread-self symlink

Same story: I have WIP patch to make it faster, so better have a test
as well.

Link: http://lkml.kernel.org/r/20180627195209.GC18113@avx2
Signed-off-by: Alexey

proc: test /proc/thread-self symlink

Same story: I have WIP patch to make it faster, so better have a test
as well.

Link: http://lkml.kernel.org/r/20180627195209.GC18113@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

proc: test /proc/self symlink

There are plans to change how /proc/self result is calculated,
for that a test is necessary.

Use direct system call because of this whole getpid caching story.

Link:

proc: test /proc/self symlink

There are plans to change how /proc/self result is calculated,
for that a test is necessary.

Use direct system call because of this whole getpid caching story.

Link: http://lkml.kernel.org/r/20180627195103.GB18113@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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tools/testing/selftests/proc: test /proc/*/fd a bit (+ PF_KTHREAD is ABI!)

* Test lookup in /proc/self/fd.
"map_files" lookup story showed that lookup is not that simple.

* Test that all those sy

tools/testing/selftests/proc: test /proc/*/fd a bit (+ PF_KTHREAD is ABI!)

* Test lookup in /proc/self/fd.
"map_files" lookup story showed that lookup is not that simple.

* Test that all those symlinks open the same file.
Check with (st_dev, st_info).

* Test that kernel threads do not have anything in their /proc/*/fd/
directory.

Now this is where things get interesting.

First, kernel threads aren't pinned by /proc/self or equivalent,
thus some "atomicity" is required.

Second, ->comm can contain whitespace and ')'.
No, they are not escaped.

Third, the only reliable way to check if process is kernel thread
appears to be field #9 in /proc/*/stat.

This field is struct task_struct::flags in decimal!
Check is done by testing PF_KTHREAD flags like we do in kernel.

PF_KTREAD value is a part of userspace ABI !!!

Other methods for determining kernel threadness are not reliable:
* RSS can be 0 if everything is swapped, even while reading
from /proc/self.

* ->total_vm CAN BE ZERO if process is finishing

munmap(NULL, whole address space);

* /proc/*/maps and similar files can be empty because unmapping
everything works. Read returning 0 can't distinguish between
kernel thread and such suicide process.

Link: http://lkml.kernel.org/r/20180505000414.GA15090@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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proc: selftests: test /proc/uptime

The only tests I could come up with for /proc/uptime are:
- test that values increase monotonically for 1 second,
- bounce around CPUs and test the same thing.

proc: selftests: test /proc/uptime

The only tests I could come up with for /proc/uptime are:
- test that values increase monotonically for 1 second,
- bounce around CPUs and test the same thing.

Avoid glibc like plague for affinity given patches like this:
https://marc.info/?l=linux-kernel&m=152130031912594&w=4

Link: http://lkml.kernel.org/r/20180317165235.GB3445@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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proc: selftests: shotgun testing of read/readdir/readlink/write

Perform reads with nearly everything in /proc, and some writing as well.

Hopefully memleak checkers and KASAN will find something.

[

proc: selftests: shotgun testing of read/readdir/readlink/write

Perform reads with nearly everything in /proc, and some writing as well.

Hopefully memleak checkers and KASAN will find something.

[[email protected]: /proc/kmsg can and will block if read under root]
Link: http://lkml.kernel.org/r/20180316232147.GA20146@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
[[email protected]: /proc/sysrq-trigger lives on the ground floor]
Link: http://lkml.kernel.org/r/20180317164911.GA3445@avx2
Link: http://lkml.kernel.org/r/20180315201251.GA12396@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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proc: add selftest for last field of /proc/loadavg

Test fork counter formerly known as ->last_pid, the only part of
/proc/loadavg which can be tested.

Testing in init pid namespace is not reliable

proc: add selftest for last field of /proc/loadavg

Test fork counter formerly known as ->last_pid, the only part of
/proc/loadavg which can be tested.

Testing in init pid namespace is not reliable because of background
activity.

Link: http://lkml.kernel.org/r/20180311152241.GA26247@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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proc: fix /proc/*/map_files lookup some more

I totally forgot that _parse_integer() accepts arbitrary amount of
leading zeroes leading to the following lookups:

OK
# readlink /proc/1/map_files/5

proc: fix /proc/*/map_files lookup some more

I totally forgot that _parse_integer() accepts arbitrary amount of
leading zeroes leading to the following lookups:

OK
# readlink /proc/1/map_files/56427ecba000-56427eddc000
/lib/systemd/systemd

bogus
# readlink /proc/1/map_files/00000000000056427ecba000-56427eddc000
/lib/systemd/systemd
# readlink /proc/1/map_files/56427ecba000-00000000000056427eddc000
/lib/systemd/systemd

Link: http://lkml.kernel.org/r/20180303215130.GA23480@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Reviewed-by: Cyrill Gorcunov <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Cc: Pavel Emelyanov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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proc: test /proc/self/syscall

Read from /proc/self/syscall should yield read system call and correct
args in the output as current is reading /proc/self/syscall.

Link: http://lkml.kernel.org/r/2018

proc: test /proc/self/syscall

Read from /proc/self/syscall should yield read system call and correct
args in the output as current is reading /proc/self/syscall.

Link: http://lkml.kernel.org/r/20180226212145.GB742@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

proc: test /proc/self/wchan

This patch starts testing /proc. Many more tests to come (I promise).

Read from /proc/self/wchan should always return "0" as current is in
TASK_RUNNING state while read

proc: test /proc/self/wchan

This patch starts testing /proc. Many more tests to come (I promise).

Read from /proc/self/wchan should always return "0" as current is in
TASK_RUNNING state while reading /proc/self/wchan.

Link: http://lkml.kernel.org/r/20180226212006.GA742@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...