Debian Bug report logs - #851427
sysvinit makes /dev/shm a symlink to /run/shm, should be other way round

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Message #5 received at submit@bugs.debian.org (full text, mbox, reply):

From: Simon McVittie <smcv@debian.org>

To: submit@bugs.debian.org

Subject: sysvinit makes /dev/shm a symlink to /run/shm, should be other way round

Date: Sat, 14 Jan 2017 21:15:42 +0000

Package: initscripts
Version: 2.88dsf-59.8
Severity: normal

On Sat, 14 Jan 2017 at 11:00:51 -0800, Steve Langasek wrote:
> On Fri, Jan 13, 2017 at 03:54:30PM +0000, Simon McVittie wrote:
> > If I'm reading the initscripts code correctly, sysvinit does the reverse
> > by default, for some reason (/run/shm is the mount point and /dev/shm the
> > symlink). I think the motivation might have been to be able to use the
> > same tmpfs for /run and /run/shm,
> 
> I recall this being a misguided attempt to move it out of /dev "because it's
> not a device".  The migration did not go well, especially in the face of
> chroots that need to have it mounted, and since systemd did not handle this
> the same way sysvinit had, we effectively now have a mess in the other
> direction.
> 
> We should fix it so that everything again treats /dev/shm as the mountpoint.

Let's have a bug number for that, then. Please escalate its severity if you
think that's correct.

Steps to reproduce:

* install Debian (I used vmdebootstrap according to autopkgtest-virt-qemu(1))
* apt install sysvinit-core
* reboot
* mount
* ls -al /dev/shm /root/shm

Expected result:

* /dev/shm is a tmpfs
* /run/shm is a symlink with target /dev/shm

Actual result:

* /dev/shm is a symlink with target /run/shm
* /run/shm is a tmpfs

----

This might also be related to #697003, #818442.

Message #10 received at 851427@bugs.debian.org (full text, mbox, reply):

From: Holger Levsen <holger@layer-acht.org>

To: Simon McVittie <smcv@debian.org>, 851427@bugs.debian.org

Subject: Re: Bug#851427: sysvinit makes /dev/shm a symlink to /run/shm, should be other way round

Date: Sat, 14 Jan 2017 21:50:43 +0000

[Message part 1 (text/plain, inline)]

Hi Simon,

thanks for this bug report, much appreciated!

On Sat, Jan 14, 2017 at 09:15:42PM +0000, Simon McVittie wrote:
> Expected result:
> 
> * /dev/shm is a tmpfs

and /dev/shm is owned by root:root and has perms 1755?


-- 
cheers,
	Holger

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Message #15 received at 851427@bugs.debian.org (full text, mbox, reply):

From: Holger Levsen <holger@layer-acht.org>

To: Simon McVittie <smcv@debian.org>, 851427@bugs.debian.org

Subject: Re: Bug#851427: sysvinit makes /dev/shm a symlink to /run/shm, should be other way round

Date: Sat, 14 Jan 2017 22:04:16 +0000

[Message part 1 (text/plain, inline)]

On Sat, Jan 14, 2017 at 09:50:43PM +0000, Holger Levsen wrote:
> and /dev/shm is owned by root:root and has perms 1755?

actually I have both 1777 and 0755 here, which of the two is correct or
are both fine??


-- 
cheers,
	Holger

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Message #20 received at 851427@bugs.debian.org (full text, mbox, reply):

From: Henrique de Moraes Holschuh <hmh@debian.org>

To: Holger Levsen <holger@layer-acht.org>, 851427@bugs.debian.org

Cc: Simon McVittie <smcv@debian.org>

Subject: Re: [Pkg-sysvinit-devel] Bug#851427: sysvinit makes /dev/shm a symlink to /run/shm, should be other way round

Date: Sat, 14 Jan 2017 20:24:15 -0200

On Sat, 14 Jan 2017, Holger Levsen wrote:
> On Sat, Jan 14, 2017 at 09:50:43PM +0000, Holger Levsen wrote:
> > and /dev/shm is owned by root:root and has perms 1755?
> 
> actually I have both 1777 and 0755 here, which of the two is correct or
> are both fine??

It has to be mode 01777, read+write.  Otherwise, it breaks glibc's shm_*
and SuS/POSIX compliance, and you get to keep the pieces of everthing
that will fail in both subtle, and very non-subtle ways.

Such as Google Chrome / chromium.

-- 
  Henrique Holschuh

Message #25 received at 851427@bugs.debian.org (full text, mbox, reply):

From: Simon McVittie <smcv@debian.org>

To: Holger Levsen <holger@layer-acht.org>

Cc: 851427@bugs.debian.org

Subject: Re: Bug#851427: sysvinit makes /dev/shm a symlink to /run/shm, should be other way round

Date: Sat, 14 Jan 2017 23:13:30 +0000

On Sat, 14 Jan 2017 at 21:50:43 +0000, Holger Levsen wrote:
> On Sat, Jan 14, 2017 at 09:15:42PM +0000, Simon McVittie wrote:
> > Expected result:
> > 
> > * /dev/shm is a tmpfs
> 
> and /dev/shm is owned by root:root and has perms 1755?

No, it should have the ownership and permissions that are the default
for tmpfs filesystems (root:root 01777), the same as a correctly
configured /tmp or /var/tmp.

$ ls -ld /dev/shm
drwxrwxrwt 2 root root 220 Jan 14 20:44 /dev/shm

Regards,
    S

Message #30 received at 851427@bugs.debian.org (full text, mbox, reply):

From: Holger Levsen <holger@layer-acht.org>

To: Simon McVittie <smcv@debian.org>, Henrique de Moraes Holschuh <hmh@debian.org>

Cc: 851427@bugs.debian.org

Subject: Re: Bug#851427: sysvinit makes /dev/shm a symlink to /run/shm, should be other way round

Date: Sun, 15 Jan 2017 12:14:54 +0000

[Message part 1 (text/plain, inline)]

Simon, Henrique,

thank you both for clarifying and explaining why!

On Sat, Jan 14, 2017 at 11:13:30PM +0000, Simon McVittie wrote:
> No, it should have the ownership and permissions that are the default
> for tmpfs filesystems (root:root 01777)…


-- 
cheers,
	Holger

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Message #35 received at 851427@bugs.debian.org (full text, mbox, reply):

From: Dolphin Oracle <dolphinoracle@gmail.com>

To: 851427@bugs.debian.org

Subject: Re: Bug#851427: sysvinit makes /dev/shm a symlink to /run/shm, should be other way round

Date: Thu, 10 Jan 2019 10:54:06 -0500

[Message part 1 (text/plain, inline)]

the buster version of sysvinit initscripts still mounts the with /run/shm
as the mount point for the tmpfs and /dev/shm as a symlink.

just adding on to the discussion...the situation actually prevents running
certain flatpak applications.

modifying mount-functions.sh per the attached will reverse the situation,
although there is still some migration code in there that strictly speaking
isn't necessary.

[Message part 2 (text/html, inline)]

[mount-functions.sh-testing-antix-rev1.tar.gz (application/x-gzip, attachment)]

Message #40 received at 851427@bugs.debian.org (full text, mbox, reply):

From: Dmitry Bogatov <KAction@debian.org>

To: Dolphin Oracle <dolphinoracle@gmail.com>, 851427@bugs.debian.org

Subject: Re: Bug#851427: sysvinit makes /dev/shm a symlink to /run/shm, should be other way round

Date: Sat, 12 Jan 2019 12:41:38 +0000

[ Please, next time attach patch, not whole file. Much more convenient
  for review ]

[2019-01-10 10:54] Dolphin Oracle <dolphinoracle@gmail.com>
> the buster version of sysvinit initscripts still mounts the with /run/shm
> as the mount point for the tmpfs and /dev/shm as a symlink.
>
> just adding on to the discussion...the situation actually prevents running
> certain flatpak applications.
> 
> modifying mount-functions.sh per the attached will reverse the situation,

Works fine to me, I intend to accept it. Dear co-maintainers,
any objections?

> although there is still some migration code in there that strictly speaking
> isn't necessary.

Further patches are welcome. Just remember, that not only fresh installs
must work fine, but also upgrade from stable must be smooth and painless.

Here is patch for convenience of other developers:

diff --git a/debian/src/initscripts/lib/init/mount-functions.sh b/debian/src/initscripts/lib/init/mount-functions.sh
index 7511761c..98f53a86 100644
--- a/debian/src/initscripts/lib/init/mount-functions.sh
+++ b/debian/src/initscripts/lib/init/mount-functions.sh
@@ -436,7 +436,7 @@ post_mountall ()
 	# directory.  The migration logic will then take care of the
 	# rest.  Note that it will take a second boot to fully
 	# migrate; it should only ever be needed on broken systems.
-	RAMSHM_ON_DEV_SHM="no"
+	RAMSHM_ON_DEV_SHM="yes"
 	if read_fstab_entry "/dev/shm"; then
 	    RAMSHM_ON_DEV_SHM="yes"
 	fi
@@ -559,8 +559,8 @@ mount_shm ()
 {
 	MNTMODE="$1"
 
-	RAMSHM_ON_DEV_SHM="no"
-	SHMDIR="/run/shm"
+	RAMSHM_ON_DEV_SHM="yes"
+	SHMDIR="/dev/shm"
 	if read_fstab_entry "/dev/shm"; then
 		if [ "$MNTMODE" = "mount_noupdate" ]; then
 			log_warning_msg "Warning: fstab entry for /dev/shm; should probably be for /run/shm unless working around a bug in the Oracle database"
@@ -706,13 +706,3 @@ is_fastboot_active() {
 	done
 	return 1
 }

Message #45 received at 851427@bugs.debian.org (full text, mbox, reply):

From: Dolphin Oracle <dolphinoracle@gmail.com>

To: Dmitry Bogatov <KAction@debian.org>

Cc: 851427@bugs.debian.org

Subject: Re: Bug#851427: sysvinit makes /dev/shm a symlink to /run/shm, should be other way round

Date: Sat, 12 Jan 2019 08:02:35 -0500

[Message part 1 (text/plain, inline)]

Thank you.  I will make sure to use a patch in the future.


On Jan 12, 2019 7:41 AM, "Dmitry Bogatov" <KAction@debian.org> wrote:


[ Please, next time attach patch, not whole file. Much more convenient
  for review ]

[2019-01-10 10:54] Dolphin Oracle <dolphinoracle@gmail.com>

> the buster version of sysvinit initscripts still mounts the with /run/shm
> as the mount point for the tmpfs and /dev/shm as a symlink.
>
> just adding on to the discussion...the situation actually prevents running
> certain flatpak applications.
>
> modifying mount-functions.sh per the attached will reverse the situation,

Works fine to me, I intend to accept it. Dear co-maintainers,
any objections?


> although there is still some migration code in there that strictly
speaking
> isn't necessary.

Further patches are welcome. Just remember, that not only fresh installs
must work fine, but also upgrade from stable must be smooth and painless.

Here is patch for convenience of other developers:

diff --git a/debian/src/initscripts/lib/init/mount-functions.sh
b/debian/src/initscripts/lib/init/mount-functions.sh
index 7511761c..98f53a86 100644
--- a/debian/src/initscripts/lib/init/mount-functions.sh
+++ b/debian/src/initscripts/lib/init/mount-functions.sh
@@ -436,7 +436,7 @@ post_mountall ()
        # directory.  The migration logic will then take care of the
        # rest.  Note that it will take a second boot to fully
        # migrate; it should only ever be needed on broken systems.
-       RAMSHM_ON_DEV_SHM="no"
+       RAMSHM_ON_DEV_SHM="yes"
        if read_fstab_entry "/dev/shm"; then
            RAMSHM_ON_DEV_SHM="yes"
        fi
@@ -559,8 +559,8 @@ mount_shm ()
 {
        MNTMODE="$1"

-       RAMSHM_ON_DEV_SHM="no"
-       SHMDIR="/run/shm"
+       RAMSHM_ON_DEV_SHM="yes"
+       SHMDIR="/dev/shm"
        if read_fstab_entry "/dev/shm"; then
                if [ "$MNTMODE" = "mount_noupdate" ]; then
                        log_warning_msg "Warning: fstab entry for /dev/shm;
should probably be for /run/shm unless working around a bug in the Oracle
database"
@@ -706,13 +706,3 @@ is_fastboot_active() {
        done
        return 1
 }

[Message part 2 (text/html, inline)]

Message #50 received at 851427-close@bugs.debian.org (full text, mbox, reply):

From: Dmitry Bogatov <KAction@debian.org>

To: 851427-close@bugs.debian.org

Subject: Bug#851427: fixed in sysvinit 2.93-4

Date: Sat, 19 Jan 2019 21:50:01 +0000

Source: sysvinit
Source-Version: 2.93-4

We believe that the bug you reported is fixed in the latest version of
sysvinit, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 851427@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Dmitry Bogatov <KAction@debian.org> (supplier of updated sysvinit package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

Format: 1.8
Date: Sat, 19 Jan 2019 21:32:52 +0000
Source: sysvinit
Binary: sysvinit-core sysvinit-utils sysv-rc initscripts bootlogd
Architecture: source
Version: 2.93-4
Distribution: unstable
Urgency: medium
Maintainer: Debian sysvinit maintainers <debian-init-diversity@chiark.greenend.org.uk>
Changed-By: Dmitry Bogatov <KAction@debian.org>
Description:
 bootlogd   - daemon to log boot messages
 initscripts - scripts for initializing and shutting down the system
 sysv-rc    - System-V-like runlevel change mechanism
 sysvinit-core - System-V-like init utilities
 sysvinit-utils - System-V-like utilities
Closes: 851427 918966
Changes:
 sysvinit (2.93-4) unstable; urgency=medium
 .
   * Drop unneeded `40_multiarch_libcrypt.patch': upstream Makefile
     correctly supplies -lcrypt flag by itself.
   * Make debian/upstream/signing-key.asc minimal
   * Check for presence of backlight-related virtual files in `brightness'
     initscript (Closes: #918966)
   * Make /run/shm symlink to /dev/shm, not other way around (Closes: #851427)
     + Thanks: Dolphin Oracle <dolphinoracle@gmail.com>
   * Replace `debian/deps-mount' script with more straightforward dependency
     on `mount [linux-any]'.
   * Move {rc, rcS} scripts from /usr/libexec to /lib for convenience of
     non-users of initramfs.
   * Drop per-binary-package copyright files, superseded by dep5
     `debian/copyright'.
Checksums-Sha1:
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 8c8476822f617be2f48d2308c702eec4a569332f 127088 sysvinit_2.93-4.debian.tar.xz
 a98ab0e58e2ff36b2d648be52e501c2c73b86d49 5680 sysvinit_2.93-4_source.buildinfo
Checksums-Sha256:
 2d0d434b8468f1ba17e7c1f45585357d303650bd5b41343dbcffb25a267a04bb 2657 sysvinit_2.93-4.dsc
 39eeb895132e89364cfd02309aa61bcf708c781ad48ed8cd3ef551b9dbdeb50d 127088 sysvinit_2.93-4.debian.tar.xz
 badeb0df140dcedbef0d7f7483a61658147dc3d56bcd037cfa08287d78de1100 5680 sysvinit_2.93-4_source.buildinfo
Files:
 4f8a3386ed5d12f09b1d104de8802fdb 2657 admin optional sysvinit_2.93-4.dsc
 01285337a60192d801e6b66a163f19f9 127088 admin optional sysvinit_2.93-4.debian.tar.xz
 d7bf9cb3c228e497ffe20d622112969c 5680 admin optional sysvinit_2.93-4_source.buildinfo

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