| Message ID | 20191209151256.2497534-4-arnd@arndb.de |
|---|---|
| State | RFC |
| Delegated to: | David Miller |
| Headers | show |
| Series | [1/4,net-next] wan: remove stale Kconfig entries | expand |
On Mon, Dec 09, 2019 at 04:12:56PM +0100, Arnd Bergmann wrote: > syzbot keeps finding issues in the X.25 implementation that nobody is > interested in fixing. Given that all the x25 patches of the past years > that are not global cleanups tend to fix user-triggered oopses, is it > time to just retire the subsystem? > > I looked a bit closer and found: > > - we used to support x25 hardware in linux, but with WAN_ROUTER > removed in linux-3.9 and isdn4linux removed in 5.3, there is only hdlc, > ethernet and the N_X25 tty ldisc left. Out of these, only HDLC_X25 made > it beyond the experimental stage, so this is probably what everyone > uses if there are users at all. > > - The most common hdlc hardware that people seem to be using are > the "farsync" PCIe and USB adapters. Linux only has drivers for the > older PCI devices from that series, but no hardware that works on > modern systems. > > - The manufacturer still updates their own kernel drivers and provides > support, but ships that with a fork or rewrite of the subsystem > code now. Kevin Curtis is also listed as maintainer, but appears to > have given up in 2013 after [1]. > > - The most popular software implementation appears to be X25 over TCP > (XOT), which is supported by Farsite and other out-of-tree stacks but > never had an implementation in mainline. > > - Most other supported HDLC hardware that we supoprt is for the ISA or > PCI buses. There are newer PCIe or USB devices, but those all require > a custom device driver and often a custom subsystem, none of which got > submitted for mainline inclusion. This includes hardware from Microgate > (SyncLink), Comtrol (RocketPort Express) and Sealevel (SeaMAC). > > - The X.25 subsystem is listed as "odd fixes", but the last reply on > the netdev mailing list from the maintainer was also in 2013[2]. > > - The HDLC subsystem itself is listed as maintained by Krzysztof Halasa, > and there were new drivers merged for SoC based devices as late as > 2016 by Zhao Qiang: Freescale/NXP QUICC Engine and Maxim ds26522. > There has not been much work on HDLC or drivers/net/wan recently, > but both developers are still responsive on the mailing list and > work on other parts of the kernel. > > Based on the above, I would conclude that X.25 can probably get moved > to staging as keeping it in the kernel seems to do more harm than good, > but HDLC below it should probably stay as there it seems there are still > users of a small subset of the mainline drivers. > > Move all of X.25 into drivers/staging for now, with a projected removal > date set for Linux-5.8. > > Cc: Eric Biggers <ebiggers@kernel.org> > Cc: Andrew Hendry <andrew.hendry@gmail.com> > Cc: linux-x25@vger.kernel.org > Cc: Kevin Curtis <kevin.curtis@farsite.com> > Cc: "R.J.Dunlop" <bob.dunlop@farsite.com> > Cc: Zhao Qiang <qiang.zhao@nxp.com> > Cc: Krzysztof Halasa <khc@pm.waw.pl> > Reported-by: syzbot+429c200ffc8772bfe070@syzkaller.appspotmail.com > Reported-by: syzbot+eec0c87f31a7c3b66f7b@syzkaller.appspotmail.com > Link: https://syzkaller.appspot.com/bug?id=5b0ecf0386f56be7fe7210a14d0f62df765c0c39 > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > ---- > > If anyone has different views or additional information, let us know. > > If you agree with the above, please Ack. ACK! Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
From: Arnd Bergmann <arnd@arndb.de> Date: Mon, 9 Dec 2019 16:12:56 +0100 > syzbot keeps finding issues in the X.25 implementation that nobody is > interested in fixing. Given that all the x25 patches of the past years > that are not global cleanups tend to fix user-triggered oopses, is it > time to just retire the subsystem? I have a bug fix that I'm currently applying to 'net' right now actually: https://patchwork.ozlabs.org/patch/1205973/ So your proposal might be a bit premature.
On Mon, Dec 9, 2019 at 7:29 PM David Miller <davem@davemloft.net> wrote: > > From: Arnd Bergmann <arnd@arndb.de> > Date: Mon, 9 Dec 2019 16:12:56 +0100 > > > syzbot keeps finding issues in the X.25 implementation that nobody is > > interested in fixing. Given that all the x25 patches of the past years > > that are not global cleanups tend to fix user-triggered oopses, is it > > time to just retire the subsystem? > > I have a bug fix that I'm currently applying to 'net' right now actually: > > https://patchwork.ozlabs.org/patch/1205973/ > > So your proposal might be a bit premature. Ok, makes sense. Looking back in the history, I also see other bugfixes from the same author. Adding Martin Schiller to Cc: for a few questions: - What hardware are you using for X.25? - Would you be available to be listed in the MAINTAINERS file as a contact for net/x25? - Does your bug fix address the latest issue found by syzbot[1], or do you have an idea to fix it if not? Arnd [1] https://lore.kernel.org/netdev/CAK8P3a0LdF+aQ1hnZrVKkNBQaum0WqW1jyR7_Eb+JRiwyHWr6Q@mail.gmail.com/
On 2019-12-09 20:26, Arnd Bergmann wrote: > On Mon, Dec 9, 2019 at 7:29 PM David Miller <davem@davemloft.net> > wrote: >> >> From: Arnd Bergmann <arnd@arndb.de> >> Date: Mon, 9 Dec 2019 16:12:56 +0100 >> >> > syzbot keeps finding issues in the X.25 implementation that nobody is >> > interested in fixing. Given that all the x25 patches of the past years >> > that are not global cleanups tend to fix user-triggered oopses, is it >> > time to just retire the subsystem? >> >> I have a bug fix that I'm currently applying to 'net' right now >> actually: >> >> https://patchwork.ozlabs.org/patch/1205973/ >> >> So your proposal might be a bit premature. > > Ok, makes sense. Looking back in the history, I also see other bugfixes > from the same author. > > Adding Martin Schiller to Cc: for a few questions: > > - What hardware are you using for X.25? I would say that X.25 is (at least in Germany) not dead yet. For example, it is still used in the railway network of the Deutsche Bahn AG in many different areas. [1] We deliver products for this and use the Linux X.25 stack with some bugfixes and extensions that I would like to get upstream. As hardware/interfaces we use X.21bis/G.703 adapters, which are connected via HDLC_X25 and LAPB. Also for this there are extensions and bugfixes, which I would like to include in the kernel. > - Would you be available to be listed in the MAINTAINERS file > as a contact for net/x25? Yes, you can add me to the MAINTAINERS file. I have only limited time, but I will try to follow all requests concerning this subsystem. > - Does your bug fix address the latest issue found by syzbot[1], > or do you have an idea to fix it if not? I don't have a direct solution for the concrete problem mentioned above, but at first sight I would say that the commit 95d6ebd53c79 ("net/x25: fix use-after-free in x25_device_event()") holds the wrong lock (&x25_list_lock). Shouldn't this be the lock &x25_neigh_list_lock as in x25_get_neigh(), where x25_neigh_hold() is called? > > Arnd > > [1] > https://lore.kernel.org/netdev/CAK8P3a0LdF+aQ1hnZrVKkNBQaum0WqW1jyR7_Eb+JRiwyHWr6Q@mail.gmail.com/
On Tue, Dec 10, 2019 at 9:59 AM Martin Schiller <ms@dev.tdt.de> wrote: > On 2019-12-09 20:26, Arnd Bergmann wrote: > > On Mon, Dec 9, 2019 at 7:29 PM David Miller <davem@davemloft.net> > > wrote: > >> > >> From: Arnd Bergmann <arnd@arndb.de> > >> Date: Mon, 9 Dec 2019 16:12:56 +0100 > >> > >> > syzbot keeps finding issues in the X.25 implementation that nobody is > >> > interested in fixing. Given that all the x25 patches of the past years > >> > that are not global cleanups tend to fix user-triggered oopses, is it > >> > time to just retire the subsystem? > >> > >> I have a bug fix that I'm currently applying to 'net' right now > >> actually: > >> > >> https://patchwork.ozlabs.org/patch/1205973/ > >> > >> So your proposal might be a bit premature. > > > > Ok, makes sense. Looking back in the history, I also see other bugfixes > > from the same author. > > > > Adding Martin Schiller to Cc: for a few questions: > > > > - What hardware are you using for X.25? > > I would say that X.25 is (at least in Germany) not dead yet. For > example, it is still used in the railway network of the Deutsche Bahn AG > in many different areas. [1] > > We deliver products for this and use the Linux X.25 stack with some > bugfixes and extensions that I would like to get upstream. Right, when I looked for possible users, I found several examples where X.25 is still relevant, my impression was just that none of those were using the mainline Linux network stack. Thank you for clarifying that. > As hardware/interfaces we use X.21bis/G.703 adapters, which are > connected via > HDLC_X25 and LAPB. Also for this there are extensions and bugfixes, > which I would like to include in the kernel. > > - Would you be available to be listed in the MAINTAINERS file > > as a contact for net/x25? > > Yes, you can add me to the MAINTAINERS file. > I have only limited time, but I will try to follow all requests > concerning this subsystem. Great! I don't expect there to be a lot of work, but it definitely helps to have someone who can look at the occasional build failure or code cleanup patch. If this works for everyone, I'd submit the following patch: commit b63caa9a8d86a5bfc64052bf9aab9b22181120fd (HEAD) Author: Arnd Bergmann <arnd@arndb.de> Date: Tue Dec 10 14:28:39 2019 +0100 MAINTAINERS: add new X.25 maintainer Martin Schiller is using the Linux X.25 stack on top of HDLC and X.21 networks. He agreed to be listed as a maintainer to take care of odd fixes. Add him as the primary contact for net/x25 and net/lapb, as well as a reviewer for drivers/net/wan, which contains the HDLC code. Cc: Martin Schiller <ms@dev.tdt.de> Cc: Andrew Hendry <andrew.hendry@gmail.com> Cc: Krzysztof Halasa <khc@pm.waw.pl> Link: https://lore.kernel.org/netdev/407acd92c92c3ba04578da89b1a0f191@dev.tdt.de/ Signed-off-by: Arnd Bergmann <arnd@arndb.de> diff --git a/MAINTAINERS b/MAINTAINERS index 8e58410a799a..00b624b96103 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -6889,6 +6889,7 @@ F: Documentation/i2c/muxes/i2c-mux-gpio.rst GENERIC HDLC (WAN) DRIVERS M: Krzysztof Halasa <khc@pm.waw.pl> +R: Martin Schiller <ms@dev.tdt.de> W: http://www.kernel.org/pub/linux/utils/net/hdlc/ S: Maintained F: drivers/net/wan/c101.c @@ -9255,13 +9256,6 @@ S: Maintained F: arch/mips/lantiq F: drivers/soc/lantiq -LAPB module -L: linux-x25@vger.kernel.org -S: Orphan -F: Documentation/networking/lapb-module.txt -F: include/*/lapb.h -F: net/lapb/ - LASI 53c700 driver for PARISC M: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> L: linux-scsi@vger.kernel.org @@ -17911,11 +17905,16 @@ S: Maintained N: axp[128] X.25 NETWORK LAYER +M: Martin Schiller <ms@dev.tdt.de> M: Andrew Hendry <andrew.hendry@gmail.com> L: linux-x25@vger.kernel.org S: Odd Fixes F: Documentation/networking/x25* +F: Documentation/networking/lapb-module.txt +F: include/linux/lapb.h F: include/net/x25* +F: include/uapi/linux/x25.h +F: net/lapb/ F: net/x25/ X86 ARCHITECTURE (32-BIT AND 64-BIT) ----- > > - Does your bug fix address the latest issue found by syzbot[1], > > or do you have an idea to fix it if not? > > I don't have a direct solution for the concrete problem mentioned above, > but at > first sight I would say that the commit 95d6ebd53c79 ("net/x25: fix > use-after-free in x25_device_event()") holds the wrong lock > (&x25_list_lock). > Shouldn't this be the lock &x25_neigh_list_lock as in x25_get_neigh(), > where x25_neigh_hold() is called? After looking at it again, my best guess is something else: x25_wait_for_connection_establishment() calls release_sock()/lock_sock() while waiting. At this point, a concurrent x25_connect() can overwrite the x25->neighbour variable, which needs to be checked again before calling x25_neigh_put(). Arnd
On 2019-12-10 14:51, Arnd Bergmann wrote: > On Tue, Dec 10, 2019 at 9:59 AM Martin Schiller <ms@dev.tdt.de> wrote: >> On 2019-12-09 20:26, Arnd Bergmann wrote: >> > On Mon, Dec 9, 2019 at 7:29 PM David Miller <davem@davemloft.net> >> > wrote: >> >> >> >> From: Arnd Bergmann <arnd@arndb.de> >> >> Date: Mon, 9 Dec 2019 16:12:56 +0100 >> >> >> >> > syzbot keeps finding issues in the X.25 implementation that nobody is >> >> > interested in fixing. Given that all the x25 patches of the past years >> >> > that are not global cleanups tend to fix user-triggered oopses, is it >> >> > time to just retire the subsystem? >> >> >> >> I have a bug fix that I'm currently applying to 'net' right now >> >> actually: >> >> >> >> https://patchwork.ozlabs.org/patch/1205973/ >> >> >> >> So your proposal might be a bit premature. >> > >> > Ok, makes sense. Looking back in the history, I also see other bugfixes >> > from the same author. >> > >> > Adding Martin Schiller to Cc: for a few questions: >> > >> > - What hardware are you using for X.25? >> >> I would say that X.25 is (at least in Germany) not dead yet. For >> example, it is still used in the railway network of the Deutsche Bahn >> AG >> in many different areas. [1] >> >> We deliver products for this and use the Linux X.25 stack with some >> bugfixes and extensions that I would like to get upstream. > > Right, when I looked for possible users, I found several examples > where X.25 is still relevant, my impression was just that none of those > were using the mainline Linux network stack. > > Thank you for clarifying that. > >> As hardware/interfaces we use X.21bis/G.703 adapters, which are >> connected via >> HDLC_X25 and LAPB. Also for this there are extensions and bugfixes, >> which I would like to include in the kernel. > >> > - Would you be available to be listed in the MAINTAINERS file >> > as a contact for net/x25? >> >> Yes, you can add me to the MAINTAINERS file. >> I have only limited time, but I will try to follow all requests >> concerning this subsystem. > > Great! I don't expect there to be a lot of work, but it definitely > helps > to have someone who can look at the occasional build failure or > code cleanup patch. > > If this works for everyone, I'd submit the following patch: > > commit b63caa9a8d86a5bfc64052bf9aab9b22181120fd (HEAD) > Author: Arnd Bergmann <arnd@arndb.de> > Date: Tue Dec 10 14:28:39 2019 +0100 > > MAINTAINERS: add new X.25 maintainer > > Martin Schiller is using the Linux X.25 stack on top of HDLC and > X.21 networks. He agreed to be listed as a maintainer to take > care of odd fixes. > > Add him as the primary contact for net/x25 and net/lapb, as well > as a reviewer for drivers/net/wan, which contains the HDLC code. > > Cc: Martin Schiller <ms@dev.tdt.de> > Cc: Andrew Hendry <andrew.hendry@gmail.com> > Cc: Krzysztof Halasa <khc@pm.waw.pl> > Link: > https://lore.kernel.org/netdev/407acd92c92c3ba04578da89b1a0f191@dev.tdt.de/ > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > ACK! Acked-by: Martin Schiller <ms@dev.tdt.de> > diff --git a/MAINTAINERS b/MAINTAINERS > index 8e58410a799a..00b624b96103 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -6889,6 +6889,7 @@ F: > Documentation/i2c/muxes/i2c-mux-gpio.rst > > GENERIC HDLC (WAN) DRIVERS > M: Krzysztof Halasa <khc@pm.waw.pl> > +R: Martin Schiller <ms@dev.tdt.de> > W: http://www.kernel.org/pub/linux/utils/net/hdlc/ > S: Maintained > F: drivers/net/wan/c101.c > @@ -9255,13 +9256,6 @@ S: Maintained > F: arch/mips/lantiq > F: drivers/soc/lantiq > > -LAPB module > -L: linux-x25@vger.kernel.org > -S: Orphan > -F: Documentation/networking/lapb-module.txt > -F: include/*/lapb.h > -F: net/lapb/ > - > LASI 53c700 driver for PARISC > M: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> > L: linux-scsi@vger.kernel.org > @@ -17911,11 +17905,16 @@ S: Maintained > N: axp[128] > > X.25 NETWORK LAYER > +M: Martin Schiller <ms@dev.tdt.de> > M: Andrew Hendry <andrew.hendry@gmail.com> > L: linux-x25@vger.kernel.org > S: Odd Fixes > F: Documentation/networking/x25* > +F: Documentation/networking/lapb-module.txt > +F: include/linux/lapb.h > F: include/net/x25* > +F: include/uapi/linux/x25.h > +F: net/lapb/ > F: net/x25/ > > X86 ARCHITECTURE (32-BIT AND 64-BIT) > > ----- >> > - Does your bug fix address the latest issue found by syzbot[1], >> > or do you have an idea to fix it if not? >> >> I don't have a direct solution for the concrete problem mentioned >> above, >> but at >> first sight I would say that the commit 95d6ebd53c79 ("net/x25: fix >> use-after-free in x25_device_event()") holds the wrong lock >> (&x25_list_lock). >> Shouldn't this be the lock &x25_neigh_list_lock as in x25_get_neigh(), >> where x25_neigh_hold() is called? > > After looking at it again, my best guess is something else: > x25_wait_for_connection_establishment() calls > release_sock()/lock_sock() > while waiting. At this point, a concurrent x25_connect() can > overwrite the x25->neighbour variable, which needs to be checked > again before calling x25_neigh_put(). > That's a good point. I wonder why any further call to x25_connect() on the same socket isn't simply returning (EALREADY) as long as sock->state == SS_CONNECTING? Martin
Arnd, Arnd Bergmann <arnd@arndb.de> writes: > - Most other supported HDLC hardware that we supoprt is for the ISA or > PCI buses. I would be surprised if there is anybody left with ISA sync serial stuff, but the PCI hardware still has some users - these machines don't need to be upgraded yearly. Most people have migrated away, though.
On Wed, Dec 11, 2019 at 08:10:34AM +0100, Krzysztof Hałasa wrote: > Arnd, > > Arnd Bergmann <arnd@arndb.de> writes: > > > - Most other supported HDLC hardware that we supoprt is for the ISA or > > PCI buses. > > I would be surprised if there is anybody left with ISA sync serial > stuff, but the PCI hardware still has some users - these machines don't > need to be upgraded yearly. Most people have migrated away, though. Hi Krzysztof, Arnd I have a use case for hdlc_cisco and hdlc_raw_eth. But it uses a lot of out of tree code, the DAHDI driver framework for E1 cards, and an E1 card which is not part of DAHDI. Given how much of this is out of tree, i would understand if you eventually decide to remove this HDLC code. Andrew
diff --git a/MAINTAINERS b/MAINTAINERS index 32fab6fbd301..5f0786bd8e22 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -9155,9 +9155,7 @@ F: drivers/soc/lantiq LAPB module L: linux-x25@vger.kernel.org S: Orphan -F: Documentation/networking/lapb-module.txt -F: include/*/lapb.h -F: net/lapb/ +F: drivers/staging/x25/ LASI 53c700 driver for PARISC M: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> @@ -17645,9 +17643,7 @@ X.25 NETWORK LAYER M: Andrew Hendry <andrew.hendry@gmail.com> L: linux-x25@vger.kernel.org S: Odd Fixes -F: Documentation/networking/x25* -F: include/net/x25* -F: net/x25/ +F: drivers/staging/x25/ X86 ARCHITECTURE (32-BIT AND 64-BIT) M: Thomas Gleixner <tglx@linutronix.de> diff --git a/drivers/net/wan/Kconfig b/drivers/net/wan/Kconfig index 74f2bd639b07..931457129b3b 100644 --- a/drivers/net/wan/Kconfig +++ b/drivers/net/wan/Kconfig @@ -156,17 +156,6 @@ config HDLC_PPP If unsure, say N. -config HDLC_X25 - tristate "X.25 protocol support" - depends on HDLC && (LAPB=m && HDLC=m || LAPB=y) - help - Generic HDLC driver supporting X.25 over WAN connections. - - If unsure, say N. - -comment "X.25/LAPB support is disabled" - depends on HDLC && (LAPB!=m || HDLC!=m) && LAPB!=y - config PCI200SYN tristate "Goramo PCI200SYN support" depends on HDLC && PCI @@ -297,36 +286,4 @@ config IXP4XX_HSS Say Y here if you want to use built-in HSS ports on IXP4xx processor. -# X.25 network drivers -config LAPBETHER - tristate "LAPB over Ethernet driver" - depends on LAPB && X25 - ---help--- - Driver for a pseudo device (typically called /dev/lapb0) which allows - you to open an LAPB point-to-point connection to some other computer - on your Ethernet network. - - In order to do this, you need to say Y or M to the driver for your - Ethernet card as well as to "LAPB Data Link Driver". - - To compile this driver as a module, choose M here: the - module will be called lapbether. - - If unsure, say N. - -config X25_ASY - tristate "X.25 async driver" - depends on LAPB && X25 && TTY - ---help--- - Send and receive X.25 frames over regular asynchronous serial - lines such as telephone lines equipped with ordinary modems. - - Experts should note that this driver doesn't currently comply with - the asynchronous HDLS framing protocols in CCITT recommendation X.25. - - To compile this driver as a module, choose M here: the - module will be called x25_asy. - - If unsure, say N. - endif # WAN diff --git a/drivers/net/wan/Makefile b/drivers/net/wan/Makefile index 4438a0c4a272..1eb30941a445 100644 --- a/drivers/net/wan/Makefile +++ b/drivers/net/wan/Makefile @@ -12,17 +12,14 @@ obj-$(CONFIG_HDLC_RAW_ETH) += hdlc_raw_eth.o obj-$(CONFIG_HDLC_CISCO) += hdlc_cisco.o obj-$(CONFIG_HDLC_FR) += hdlc_fr.o obj-$(CONFIG_HDLC_PPP) += hdlc_ppp.o -obj-$(CONFIG_HDLC_X25) += hdlc_x25.o obj-$(CONFIG_HOSTESS_SV11) += z85230.o hostess_sv11.o obj-$(CONFIG_SEALEVEL_4021) += z85230.o sealevel.o obj-$(CONFIG_COSA) += cosa.o obj-$(CONFIG_FARSYNC) += farsync.o -obj-$(CONFIG_X25_ASY) += x25_asy.o obj-$(CONFIG_LANMEDIA) += lmc/ -obj-$(CONFIG_LAPBETHER) += lapbether.o obj-$(CONFIG_N2) += n2.o obj-$(CONFIG_C101) += c101.o obj-$(CONFIG_WANXL) += wanxl.o diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig index ab83326f4b7e..e2edb29ccb42 100644 --- a/drivers/staging/Kconfig +++ b/drivers/staging/Kconfig @@ -123,4 +123,6 @@ source "drivers/staging/exfat/Kconfig" source "drivers/staging/qlge/Kconfig" +source "drivers/staging/x25/Kconfig" + endif # STAGING diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile index dfddb9864b2e..0576784f1f11 100644 --- a/drivers/staging/Makefile +++ b/drivers/staging/Makefile @@ -52,3 +52,5 @@ obj-$(CONFIG_UWB) += uwb/ obj-$(CONFIG_USB_WUSB) += wusbcore/ obj-$(CONFIG_EXFAT_FS) += exfat/ obj-$(CONFIG_QLGE) += qlge/ +obj-$(CONFIG_X25) += x25/ +obj-$(CONFIG_LAPB) += x25/ diff --git a/Documentation/networking/lapb-module.txt b/drivers/staging/x25/Documentation/lapb-module.txt similarity index 100% rename from Documentation/networking/lapb-module.txt rename to drivers/staging/x25/Documentation/lapb-module.txt diff --git a/Documentation/networking/x25-iface.txt b/drivers/staging/x25/Documentation/x25-iface.txt similarity index 100% rename from Documentation/networking/x25-iface.txt rename to drivers/staging/x25/Documentation/x25-iface.txt diff --git a/Documentation/networking/x25.txt b/drivers/staging/x25/Documentation/x25.txt similarity index 100% rename from Documentation/networking/x25.txt rename to drivers/staging/x25/Documentation/x25.txt diff --git a/drivers/staging/x25/Kconfig b/drivers/staging/x25/Kconfig new file mode 100644 index 000000000000..18724b747a9e --- /dev/null +++ b/drivers/staging/x25/Kconfig @@ -0,0 +1,97 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# CCITT X.25 Packet Layer +# + +config X25 + tristate "CCITT X.25 Packet Layer" + depends on NET + ---help--- + X.25 is a set of standardized network protocols, similar in scope to + frame relay; the one physical line from your box to the X.25 network + entry point can carry several logical point-to-point connections + (called "virtual circuits") to other computers connected to the X.25 + network. Governments, banks, and other organizations tend to use it + to connect to each other or to form Wide Area Networks (WANs). Many + countries have public X.25 networks. X.25 consists of two + protocols: the higher level Packet Layer Protocol (PLP) (say Y here + if you want that) and the lower level data link layer protocol LAPB + (say Y to "LAPB Data Link Driver" below if you want that). + + You can read more about X.25 at <http://www.sangoma.com/tutorials/x25/> and + <http://docwiki.cisco.com/wiki/X.25>. + Information about X.25 for Linux is contained in the files + <file:Documentation/networking/x25.txt> and + <file:Documentation/networking/x25-iface.txt>. + + One connects to an X.25 network either with a dedicated network card + using the X.21 protocol (not yet supported by Linux) or one can do + X.25 over a standard telephone line using an ordinary modem (say Y + to "X.25 async driver" below) or over Ethernet using an ordinary + Ethernet card and the LAPB over Ethernet (say Y to "LAPB Data Link + Driver" and "LAPB over Ethernet driver" below). + + To compile this driver as a module, choose M here: the module + will be called x25. If unsure, say N. + +config LAPB + tristate "LAPB Data Link Driver" + depends on NET + ---help--- + Link Access Procedure, Balanced (LAPB) is the data link layer (i.e. + the lower) part of the X.25 protocol. It offers a reliable + connection service to exchange data frames with one other host, and + it is used to transport higher level protocols (mostly X.25 Packet + Layer, the higher part of X.25, but others are possible as well). + Usually, LAPB is used with specialized X.21 network cards, but Linux + currently supports LAPB only over Ethernet connections. If you want + to use LAPB connections over Ethernet, say Y here and to "LAPB over + Ethernet driver" below. Read + <file:Documentation/networking/lapb-module.txt> for technical + details. + + To compile this driver as a module, choose M here: the + module will be called lapb. If unsure, say N. + +config HDLC_X25 + tristate "X.25 protocol support" + depends on HDLC && (LAPB=m && HDLC=m || LAPB=y) + help + Generic HDLC driver supporting X.25 over WAN connections. + + If unsure, say N. + +comment "X.25/LAPB support is disabled" + depends on HDLC && (LAPB!=m || HDLC!=m) && LAPB!=y + +# X.25 network drivers +config LAPBETHER + tristate "LAPB over Ethernet driver" + depends on LAPB && X25 + ---help--- + Driver for a pseudo device (typically called /dev/lapb0) which allows + you to open an LAPB point-to-point connection to some other computer + on your Ethernet network. + + In order to do this, you need to say Y or M to the driver for your + Ethernet card as well as to "LAPB Data Link Driver". + + To compile this driver as a module, choose M here: the + module will be called lapbether. + + If unsure, say N. + +config X25_ASY + tristate "X.25 async driver" + depends on LAPB && X25 && TTY + ---help--- + Send and receive X.25 frames over regular asynchronous serial + lines such as telephone lines equipped with ordinary modems. + + Experts should note that this driver doesn't currently comply with + the asynchronous HDLS framing protocols in CCITT recommendation X.25. + + To compile this driver as a module, choose M here: the + module will be called x25_asy. + + If unsure, say N. diff --git a/net/x25/Makefile b/drivers/staging/x25/Makefile similarity index 58% rename from net/x25/Makefile rename to drivers/staging/x25/Makefile index 5dd544a231f2..d8235ac6b015 100644 --- a/net/x25/Makefile +++ b/drivers/staging/x25/Makefile @@ -9,3 +9,11 @@ x25-y := af_x25.o x25_dev.o x25_facilities.o x25_in.o \ x25_link.o x25_out.o x25_route.o x25_subr.o \ x25_timer.o x25_proc.o x25_forward.o x25-$(CONFIG_SYSCTL) += sysctl_net_x25.o + +obj-$(CONFIG_LAPB) += lapb.o + +lapb-y := lapb_in.o lapb_out.o lapb_subr.o lapb_timer.o lapb_iface.o + +obj-$(CONFIG_HDLC_X25) += hdlc_x25.o +obj-$(CONFIG_X25_ASY) += x25_asy.o +obj-$(CONFIG_LAPBETHER) += lapbether.o diff --git a/drivers/staging/x25/TODO b/drivers/staging/x25/TODO new file mode 100644 index 000000000000..bb42cf474ca1 --- /dev/null +++ b/drivers/staging/x25/TODO @@ -0,0 +1,15 @@ +Staging out of X.25 +=================== + +It appears that the X.25 socket family is not used any more with the +mainline kernel, and the git log shows a series of user-triggerable +Oopses. + +https://www.farsite.com/ still makes hardware that is being used in the +field, but that uses a custom out of tree protocol stack in place of +the kernel's AF_X25. + +If there are remaining users of this code that I missed, it can be moved +out back out of staging, otherwise it will be removed in linux-5.8. + + Arnd Bergmann <arnd@arndb.de> diff --git a/net/x25/af_x25.c b/drivers/staging/x25/af_x25.c similarity index 99% rename from net/x25/af_x25.c rename to drivers/staging/x25/af_x25.c index 6aee9f5e8e71..be950682209d 100644 --- a/net/x25/af_x25.c +++ b/drivers/staging/x25/af_x25.c @@ -54,7 +54,7 @@ #include <linux/compat.h> #include <linux/ctype.h> -#include <net/x25.h> +#include "x25.h" #include <net/compat.h> int sysctl_x25_restart_request_timeout = X25_DEFAULT_T20; diff --git a/drivers/net/wan/hdlc_x25.c b/drivers/staging/x25/hdlc_x25.c similarity index 99% rename from drivers/net/wan/hdlc_x25.c rename to drivers/staging/x25/hdlc_x25.c index 5643675ff724..32ccf0c8e040 100644 --- a/drivers/net/wan/hdlc_x25.c +++ b/drivers/staging/x25/hdlc_x25.c @@ -13,7 +13,7 @@ #include <linux/inetdevice.h> #include <linux/init.h> #include <linux/kernel.h> -#include <linux/lapb.h> +#include "linux-lapb.h" #include <linux/module.h> #include <linux/pkt_sched.h> #include <linux/poll.h> diff --git a/include/net/lapb.h b/drivers/staging/x25/lapb.h similarity index 99% rename from include/net/lapb.h rename to drivers/staging/x25/lapb.h index ccc3d1f020b0..2abab6266caf 100644 --- a/include/net/lapb.h +++ b/drivers/staging/x25/lapb.h @@ -1,8 +1,8 @@ /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LAPB_H #define _LAPB_H -#include <linux/lapb.h> #include <linux/refcount.h> +#include "linux-lapb.h" #define LAPB_HEADER_LEN 20 /* LAPB over Ethernet + a bit more */ diff --git a/net/lapb/lapb_iface.c b/drivers/staging/x25/lapb_iface.c similarity index 99% rename from net/lapb/lapb_iface.c rename to drivers/staging/x25/lapb_iface.c index 3c03f6512c5f..1231ae28ec64 100644 --- a/net/lapb/lapb_iface.c +++ b/drivers/staging/x25/lapb_iface.c @@ -34,7 +34,7 @@ #include <linux/interrupt.h> #include <linux/stat.h> #include <linux/init.h> -#include <net/lapb.h> +#include "lapb.h" static LIST_HEAD(lapb_list); static DEFINE_RWLOCK(lapb_list_lock); diff --git a/net/lapb/lapb_in.c b/drivers/staging/x25/lapb_in.c similarity index 99% rename from net/lapb/lapb_in.c rename to drivers/staging/x25/lapb_in.c index 38ae23c09e83..210f8c743b39 100644 --- a/net/lapb/lapb_in.c +++ b/drivers/staging/x25/lapb_in.c @@ -30,7 +30,7 @@ #include <linux/fcntl.h> #include <linux/mm.h> #include <linux/interrupt.h> -#include <net/lapb.h> +#include "lapb.h" /* * State machine for state 0, Disconnected State. diff --git a/net/lapb/lapb_out.c b/drivers/staging/x25/lapb_out.c similarity index 99% rename from net/lapb/lapb_out.c rename to drivers/staging/x25/lapb_out.c index 7a4d0715d1c3..d4ba7a5ebd33 100644 --- a/net/lapb/lapb_out.c +++ b/drivers/staging/x25/lapb_out.c @@ -28,7 +28,7 @@ #include <linux/fcntl.h> #include <linux/mm.h> #include <linux/interrupt.h> -#include <net/lapb.h> +#include "lapb.h" /* * This procedure is passed a buffer descriptor for an iframe. It builds diff --git a/net/lapb/lapb_subr.c b/drivers/staging/x25/lapb_subr.c similarity index 99% rename from net/lapb/lapb_subr.c rename to drivers/staging/x25/lapb_subr.c index 592a22d86a97..f5ec7868c5a4 100644 --- a/net/lapb/lapb_subr.c +++ b/drivers/staging/x25/lapb_subr.c @@ -27,7 +27,7 @@ #include <linux/fcntl.h> #include <linux/mm.h> #include <linux/interrupt.h> -#include <net/lapb.h> +#include "lapb.h" /* * This routine purges all the queues of frames. diff --git a/net/lapb/lapb_timer.c b/drivers/staging/x25/lapb_timer.c similarity index 99% rename from net/lapb/lapb_timer.c rename to drivers/staging/x25/lapb_timer.c index 8f5b17001a07..0b46163593e5 100644 --- a/net/lapb/lapb_timer.c +++ b/drivers/staging/x25/lapb_timer.c @@ -28,7 +28,7 @@ #include <linux/fcntl.h> #include <linux/mm.h> #include <linux/interrupt.h> -#include <net/lapb.h> +#include "lapb.h" static void lapb_t1timer_expiry(struct timer_list *); static void lapb_t2timer_expiry(struct timer_list *); diff --git a/drivers/net/wan/lapbether.c b/drivers/staging/x25/lapbether.c similarity index 99% rename from drivers/net/wan/lapbether.c rename to drivers/staging/x25/lapbether.c index 0f1217b506ad..6ff971705dca 100644 --- a/drivers/net/wan/lapbether.c +++ b/drivers/staging/x25/lapbether.c @@ -36,7 +36,7 @@ #include <linux/notifier.h> #include <linux/stat.h> #include <linux/module.h> -#include <linux/lapb.h> +#include "linux-lapb.h" #include <linux/init.h> #include <net/x25device.h> diff --git a/include/linux/lapb.h b/drivers/staging/x25/linux-lapb.h similarity index 100% rename from include/linux/lapb.h rename to drivers/staging/x25/linux-lapb.h diff --git a/net/x25/sysctl_net_x25.c b/drivers/staging/x25/sysctl_net_x25.c similarity index 98% rename from net/x25/sysctl_net_x25.c rename to drivers/staging/x25/sysctl_net_x25.c index e9802afa43d0..e8530a4e4856 100644 --- a/net/x25/sysctl_net_x25.c +++ b/drivers/staging/x25/sysctl_net_x25.c @@ -11,7 +11,7 @@ #include <linux/socket.h> #include <linux/netdevice.h> #include <linux/init.h> -#include <net/x25.h> +#include "x25.h" static int min_timer[] = { 1 * HZ }; static int max_timer[] = { 300 * HZ }; diff --git a/include/uapi/linux/x25.h b/drivers/staging/x25/uapi-x25.h similarity index 100% rename from include/uapi/linux/x25.h rename to drivers/staging/x25/uapi-x25.h diff --git a/include/net/x25.h b/drivers/staging/x25/x25.h similarity index 99% rename from include/net/x25.h rename to drivers/staging/x25/x25.h index ed1acc3044ac..dfbc0188e47d 100644 --- a/include/net/x25.h +++ b/drivers/staging/x25/x25.h @@ -10,10 +10,10 @@ #ifndef _X25_H #define _X25_H -#include <linux/x25.h> #include <linux/slab.h> #include <linux/refcount.h> #include <net/sock.h> +#include "uapi-x25.h" #define X25_ADDR_LEN 16 diff --git a/drivers/net/wan/x25_asy.c b/drivers/staging/x25/x25_asy.c similarity index 99% rename from drivers/net/wan/x25_asy.c rename to drivers/staging/x25/x25_asy.c index 914be5847386..3986a1160fc1 100644 --- a/drivers/net/wan/x25_asy.c +++ b/drivers/staging/x25/x25_asy.c @@ -31,7 +31,7 @@ #include <linux/etherdevice.h> #include <linux/skbuff.h> #include <linux/if_arp.h> -#include <linux/lapb.h> +#include "linux-lapb.h" #include <linux/init.h> #include <linux/rtnetlink.h> #include <linux/slab.h> diff --git a/drivers/net/wan/x25_asy.h b/drivers/staging/x25/x25_asy.h similarity index 100% rename from drivers/net/wan/x25_asy.h rename to drivers/staging/x25/x25_asy.h diff --git a/net/x25/x25_dev.c b/drivers/staging/x25/x25_dev.c similarity index 99% rename from net/x25/x25_dev.c rename to drivers/staging/x25/x25_dev.c index 00e782335cb0..dbdce9c62abd 100644 --- a/net/x25/x25_dev.c +++ b/drivers/staging/x25/x25_dev.c @@ -20,7 +20,7 @@ #include <linux/slab.h> #include <net/sock.h> #include <linux/if_arp.h> -#include <net/x25.h> +#include "x25.h" #include <net/x25device.h> static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb) diff --git a/net/x25/x25_facilities.c b/drivers/staging/x25/x25_facilities.c similarity index 99% rename from net/x25/x25_facilities.c rename to drivers/staging/x25/x25_facilities.c index 7fb327632272..17e41049cb2b 100644 --- a/net/x25/x25_facilities.c +++ b/drivers/staging/x25/x25_facilities.c @@ -22,7 +22,7 @@ #include <linux/string.h> #include <linux/skbuff.h> #include <net/sock.h> -#include <net/x25.h> +#include "x25.h" /** * x25_parse_facilities - Parse facilities from skb into the facilities structs diff --git a/net/x25/x25_forward.c b/drivers/staging/x25/x25_forward.c similarity index 99% rename from net/x25/x25_forward.c rename to drivers/staging/x25/x25_forward.c index c82999941d3f..4328f0e31482 100644 --- a/net/x25/x25_forward.c +++ b/drivers/staging/x25/x25_forward.c @@ -9,7 +9,7 @@ #include <linux/if_arp.h> #include <linux/init.h> #include <linux/slab.h> -#include <net/x25.h> +#include "x25.h" LIST_HEAD(x25_forward_list); DEFINE_RWLOCK(x25_forward_list_lock); diff --git a/net/x25/x25_in.c b/drivers/staging/x25/x25_in.c similarity index 99% rename from net/x25/x25_in.c rename to drivers/staging/x25/x25_in.c index f97c43344e95..e0c1f1484d8c 100644 --- a/net/x25/x25_in.c +++ b/drivers/staging/x25/x25_in.c @@ -27,7 +27,7 @@ #include <linux/skbuff.h> #include <net/sock.h> #include <net/tcp_states.h> -#include <net/x25.h> +#include "x25.h" static int x25_queue_rx_frame(struct sock *sk, struct sk_buff *skb, int more) { diff --git a/net/x25/x25_link.c b/drivers/staging/x25/x25_link.c similarity index 99% rename from net/x25/x25_link.c rename to drivers/staging/x25/x25_link.c index 7d02532aad0d..5c07143e557d 100644 --- a/net/x25/x25_link.c +++ b/drivers/staging/x25/x25_link.c @@ -26,7 +26,7 @@ #include <linux/skbuff.h> #include <linux/uaccess.h> #include <linux/init.h> -#include <net/x25.h> +#include "x25.h" LIST_HEAD(x25_neigh_list); DEFINE_RWLOCK(x25_neigh_list_lock); diff --git a/net/x25/x25_out.c b/drivers/staging/x25/x25_out.c similarity index 99% rename from net/x25/x25_out.c rename to drivers/staging/x25/x25_out.c index dbc0940bf35f..8f4d55e378ee 100644 --- a/net/x25/x25_out.c +++ b/drivers/staging/x25/x25_out.c @@ -23,7 +23,7 @@ #include <linux/string.h> #include <linux/skbuff.h> #include <net/sock.h> -#include <net/x25.h> +#include "x25.h" static int x25_pacsize_to_bytes(unsigned int pacsize) { diff --git a/net/x25/x25_proc.c b/drivers/staging/x25/x25_proc.c similarity index 99% rename from net/x25/x25_proc.c rename to drivers/staging/x25/x25_proc.c index 3bddcbdf2e40..4c36e64a719a 100644 --- a/net/x25/x25_proc.c +++ b/drivers/staging/x25/x25_proc.c @@ -18,7 +18,7 @@ #include <linux/export.h> #include <net/net_namespace.h> #include <net/sock.h> -#include <net/x25.h> +#include "x25.h" #ifdef CONFIG_PROC_FS diff --git a/net/x25/x25_route.c b/drivers/staging/x25/x25_route.c similarity index 99% rename from net/x25/x25_route.c rename to drivers/staging/x25/x25_route.c index b8e94d58d0f1..60f18964be0f 100644 --- a/net/x25/x25_route.c +++ b/drivers/staging/x25/x25_route.c @@ -15,7 +15,7 @@ #include <linux/if_arp.h> #include <linux/init.h> #include <linux/slab.h> -#include <net/x25.h> +#include "x25.h" LIST_HEAD(x25_route_list); DEFINE_RWLOCK(x25_route_list_lock); diff --git a/net/x25/x25_subr.c b/drivers/staging/x25/x25_subr.c similarity index 99% rename from net/x25/x25_subr.c rename to drivers/staging/x25/x25_subr.c index 8aa415a38814..7004ee53a6b0 100644 --- a/net/x25/x25_subr.c +++ b/drivers/staging/x25/x25_subr.c @@ -26,7 +26,7 @@ #include <linux/skbuff.h> #include <net/sock.h> #include <net/tcp_states.h> -#include <net/x25.h> +#include "x25.h" /* * This routine purges all of the queues of frames. diff --git a/net/x25/x25_timer.c b/drivers/staging/x25/x25_timer.c similarity index 99% rename from net/x25/x25_timer.c rename to drivers/staging/x25/x25_timer.c index 9376365cdcc9..3edcae15f897 100644 --- a/net/x25/x25_timer.c +++ b/drivers/staging/x25/x25_timer.c @@ -19,7 +19,7 @@ #include <linux/timer.h> #include <net/sock.h> #include <net/tcp_states.h> -#include <net/x25.h> +#include "x25.h" static void x25_heartbeat_expiry(struct timer_list *t); static void x25_timer_expiry(struct timer_list *t); diff --git a/include/Kbuild b/include/Kbuild index 64ab3aac7379..e26750d6ec96 100644 --- a/include/Kbuild +++ b/include/Kbuild @@ -276,7 +276,6 @@ header-test- += linux/kvm_host.h header-test- += linux/kvm_irqfd.h header-test- += linux/kvm_para.h header-test- += linux/lantiq.h -header-test- += linux/lapb.h header-test- += linux/latencytop.h header-test- += linux/led-lm3530.h header-test- += linux/leds-bd2802.h @@ -835,7 +834,6 @@ header-test- += net/ipcomp.h header-test- += net/ipconfig.h header-test- += net/iucv/af_iucv.h header-test- += net/iucv/iucv.h -header-test- += net/lapb.h header-test- += net/llc_c_ac.h header-test- += net/llc_c_st.h header-test- += net/llc_s_ac.h diff --git a/net/Kconfig b/net/Kconfig index 3101bfcbdd7a..50681046ec03 100644 --- a/net/Kconfig +++ b/net/Kconfig @@ -220,8 +220,6 @@ source "net/8021q/Kconfig" source "net/decnet/Kconfig" source "net/llc/Kconfig" source "drivers/net/appletalk/Kconfig" -source "net/x25/Kconfig" -source "net/lapb/Kconfig" source "net/phonet/Kconfig" source "net/6lowpan/Kconfig" source "net/ieee802154/Kconfig" diff --git a/net/Makefile b/net/Makefile index 449fc0b221f8..3473e68e7abe 100644 --- a/net/Makefile +++ b/net/Makefile @@ -26,8 +26,6 @@ obj-$(CONFIG_NET_KEY) += key/ obj-$(CONFIG_BRIDGE) += bridge/ obj-$(CONFIG_NET_DSA) += dsa/ obj-$(CONFIG_ATALK) += appletalk/ -obj-$(CONFIG_X25) += x25/ -obj-$(CONFIG_LAPB) += lapb/ obj-$(CONFIG_NETROM) += netrom/ obj-$(CONFIG_ROSE) += rose/ obj-$(CONFIG_AX25) += ax25/ diff --git a/net/lapb/Kconfig b/net/lapb/Kconfig deleted file mode 100644 index 6acfc999c952..000000000000 --- a/net/lapb/Kconfig +++ /dev/null @@ -1,22 +0,0 @@ -# SPDX-License-Identifier: GPL-2.0-only -# -# LAPB Data Link Drive -# - -config LAPB - tristate "LAPB Data Link Driver" - ---help--- - Link Access Procedure, Balanced (LAPB) is the data link layer (i.e. - the lower) part of the X.25 protocol. It offers a reliable - connection service to exchange data frames with one other host, and - it is used to transport higher level protocols (mostly X.25 Packet - Layer, the higher part of X.25, but others are possible as well). - Usually, LAPB is used with specialized X.21 network cards, but Linux - currently supports LAPB only over Ethernet connections. If you want - to use LAPB connections over Ethernet, say Y here and to "LAPB over - Ethernet driver" below. Read - <file:Documentation/networking/lapb-module.txt> for technical - details. - - To compile this driver as a module, choose M here: the - module will be called lapb. If unsure, say N. diff --git a/net/lapb/Makefile b/net/lapb/Makefile deleted file mode 100644 index 7be91b4c0ca0..000000000000 --- a/net/lapb/Makefile +++ /dev/null @@ -1,8 +0,0 @@ -# SPDX-License-Identifier: GPL-2.0-only -# -# Makefile for the Linux LAPB layer. -# - -obj-$(CONFIG_LAPB) += lapb.o - -lapb-y := lapb_in.o lapb_out.o lapb_subr.o lapb_timer.o lapb_iface.o diff --git a/net/x25/Kconfig b/net/x25/Kconfig deleted file mode 100644 index 2ecb2e5e241e..000000000000 --- a/net/x25/Kconfig +++ /dev/null @@ -1,34 +0,0 @@ -# SPDX-License-Identifier: GPL-2.0-only -# -# CCITT X.25 Packet Layer -# - -config X25 - tristate "CCITT X.25 Packet Layer" - ---help--- - X.25 is a set of standardized network protocols, similar in scope to - frame relay; the one physical line from your box to the X.25 network - entry point can carry several logical point-to-point connections - (called "virtual circuits") to other computers connected to the X.25 - network. Governments, banks, and other organizations tend to use it - to connect to each other or to form Wide Area Networks (WANs). Many - countries have public X.25 networks. X.25 consists of two - protocols: the higher level Packet Layer Protocol (PLP) (say Y here - if you want that) and the lower level data link layer protocol LAPB - (say Y to "LAPB Data Link Driver" below if you want that). - - You can read more about X.25 at <http://www.sangoma.com/tutorials/x25/> and - <http://docwiki.cisco.com/wiki/X.25>. - Information about X.25 for Linux is contained in the files - <file:Documentation/networking/x25.txt> and - <file:Documentation/networking/x25-iface.txt>. - - One connects to an X.25 network either with a dedicated network card - using the X.21 protocol (not yet supported by Linux) or one can do - X.25 over a standard telephone line using an ordinary modem (say Y - to "X.25 async driver" below) or over Ethernet using an ordinary - Ethernet card and the LAPB over Ethernet (say Y to "LAPB Data Link - Driver" and "LAPB over Ethernet driver" below). - - To compile this driver as a module, choose M here: the module - will be called x25. If unsure, say N.
syzbot keeps finding issues in the X.25 implementation that nobody is interested in fixing. Given that all the x25 patches of the past years that are not global cleanups tend to fix user-triggered oopses, is it time to just retire the subsystem? I looked a bit closer and found: - we used to support x25 hardware in linux, but with WAN_ROUTER removed in linux-3.9 and isdn4linux removed in 5.3, there is only hdlc, ethernet and the N_X25 tty ldisc left. Out of these, only HDLC_X25 made it beyond the experimental stage, so this is probably what everyone uses if there are users at all. - The most common hdlc hardware that people seem to be using are the "farsync" PCIe and USB adapters. Linux only has drivers for the older PCI devices from that series, but no hardware that works on modern systems. - The manufacturer still updates their own kernel drivers and provides support, but ships that with a fork or rewrite of the subsystem code now. Kevin Curtis is also listed as maintainer, but appears to have given up in 2013 after [1]. - The most popular software implementation appears to be X25 over TCP (XOT), which is supported by Farsite and other out-of-tree stacks but never had an implementation in mainline. - Most other supported HDLC hardware that we supoprt is for the ISA or PCI buses. There are newer PCIe or USB devices, but those all require a custom device driver and often a custom subsystem, none of which got submitted for mainline inclusion. This includes hardware from Microgate (SyncLink), Comtrol (RocketPort Express) and Sealevel (SeaMAC). - The X.25 subsystem is listed as "odd fixes", but the last reply on the netdev mailing list from the maintainer was also in 2013[2]. - The HDLC subsystem itself is listed as maintained by Krzysztof Halasa, and there were new drivers merged for SoC based devices as late as 2016 by Zhao Qiang: Freescale/NXP QUICC Engine and Maxim ds26522. There has not been much work on HDLC or drivers/net/wan recently, but both developers are still responsive on the mailing list and work on other parts of the kernel. Based on the above, I would conclude that X.25 can probably get moved to staging as keeping it in the kernel seems to do more harm than good, but HDLC below it should probably stay as there it seems there are still users of a small subset of the mainline drivers. Move all of X.25 into drivers/staging for now, with a projected removal date set for Linux-5.8. Cc: Eric Biggers <ebiggers@kernel.org> Cc: Andrew Hendry <andrew.hendry@gmail.com> Cc: linux-x25@vger.kernel.org Cc: Kevin Curtis <kevin.curtis@farsite.com> Cc: "R.J.Dunlop" <bob.dunlop@farsite.com> Cc: Zhao Qiang <qiang.zhao@nxp.com> Cc: Krzysztof Halasa <khc@pm.waw.pl> Reported-by: syzbot+429c200ffc8772bfe070@syzkaller.appspotmail.com Reported-by: syzbot+eec0c87f31a7c3b66f7b@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=5b0ecf0386f56be7fe7210a14d0f62df765c0c39 Signed-off-by: Arnd Bergmann <arnd@arndb.de> ---- If anyone has different views or additional information, let us know. If you agree with the above, please Ack. --- MAINTAINERS | 8 +- drivers/net/wan/Kconfig | 43 -------- drivers/net/wan/Makefile | 3 - drivers/staging/Kconfig | 2 + drivers/staging/Makefile | 2 + .../x25/Documentation}/lapb-module.txt | 0 .../staging/x25/Documentation}/x25-iface.txt | 0 .../staging/x25/Documentation}/x25.txt | 0 drivers/staging/x25/Kconfig | 97 +++++++++++++++++++ {net => drivers/staging}/x25/Makefile | 8 ++ drivers/staging/x25/TODO | 15 +++ {net => drivers/staging}/x25/af_x25.c | 2 +- drivers/{net/wan => staging/x25}/hdlc_x25.c | 2 +- {include/net => drivers/staging/x25}/lapb.h | 2 +- .../lapb => drivers/staging/x25}/lapb_iface.c | 2 +- {net/lapb => drivers/staging/x25}/lapb_in.c | 2 +- {net/lapb => drivers/staging/x25}/lapb_out.c | 2 +- {net/lapb => drivers/staging/x25}/lapb_subr.c | 2 +- .../lapb => drivers/staging/x25}/lapb_timer.c | 2 +- drivers/{net/wan => staging/x25}/lapbether.c | 2 +- .../staging/x25/linux-lapb.h | 0 {net => drivers/staging}/x25/sysctl_net_x25.c | 2 +- .../x25.h => drivers/staging/x25/uapi-x25.h | 0 {include/net => drivers/staging/x25}/x25.h | 2 +- drivers/{net/wan => staging/x25}/x25_asy.c | 2 +- drivers/{net/wan => staging/x25}/x25_asy.h | 0 {net => drivers/staging}/x25/x25_dev.c | 2 +- {net => drivers/staging}/x25/x25_facilities.c | 2 +- {net => drivers/staging}/x25/x25_forward.c | 2 +- {net => drivers/staging}/x25/x25_in.c | 2 +- {net => drivers/staging}/x25/x25_link.c | 2 +- {net => drivers/staging}/x25/x25_out.c | 2 +- {net => drivers/staging}/x25/x25_proc.c | 2 +- {net => drivers/staging}/x25/x25_route.c | 2 +- {net => drivers/staging}/x25/x25_subr.c | 2 +- {net => drivers/staging}/x25/x25_timer.c | 2 +- include/Kbuild | 2 - net/Kconfig | 2 - net/Makefile | 2 - net/lapb/Kconfig | 22 ----- net/lapb/Makefile | 8 -- net/x25/Kconfig | 34 ------- 42 files changed, 148 insertions(+), 144 deletions(-) rename {Documentation/networking => drivers/staging/x25/Documentation}/lapb-module.txt (100%) rename {Documentation/networking => drivers/staging/x25/Documentation}/x25-iface.txt (100%) rename {Documentation/networking => drivers/staging/x25/Documentation}/x25.txt (100%) create mode 100644 drivers/staging/x25/Kconfig rename {net => drivers/staging}/x25/Makefile (58%) create mode 100644 drivers/staging/x25/TODO rename {net => drivers/staging}/x25/af_x25.c (99%) rename drivers/{net/wan => staging/x25}/hdlc_x25.c (99%) rename {include/net => drivers/staging/x25}/lapb.h (99%) rename {net/lapb => drivers/staging/x25}/lapb_iface.c (99%) rename {net/lapb => drivers/staging/x25}/lapb_in.c (99%) rename {net/lapb => drivers/staging/x25}/lapb_out.c (99%) rename {net/lapb => drivers/staging/x25}/lapb_subr.c (99%) rename {net/lapb => drivers/staging/x25}/lapb_timer.c (99%) rename drivers/{net/wan => staging/x25}/lapbether.c (99%) rename include/linux/lapb.h => drivers/staging/x25/linux-lapb.h (100%) rename {net => drivers/staging}/x25/sysctl_net_x25.c (98%) rename include/uapi/linux/x25.h => drivers/staging/x25/uapi-x25.h (100%) rename {include/net => drivers/staging/x25}/x25.h (99%) rename drivers/{net/wan => staging/x25}/x25_asy.c (99%) rename drivers/{net/wan => staging/x25}/x25_asy.h (100%) rename {net => drivers/staging}/x25/x25_dev.c (99%) rename {net => drivers/staging}/x25/x25_facilities.c (99%) rename {net => drivers/staging}/x25/x25_forward.c (99%) rename {net => drivers/staging}/x25/x25_in.c (99%) rename {net => drivers/staging}/x25/x25_link.c (99%) rename {net => drivers/staging}/x25/x25_out.c (99%) rename {net => drivers/staging}/x25/x25_proc.c (99%) rename {net => drivers/staging}/x25/x25_route.c (99%) rename {net => drivers/staging}/x25/x25_subr.c (99%) rename {net => drivers/staging}/x25/x25_timer.c (99%) delete mode 100644 net/lapb/Kconfig delete mode 100644 net/lapb/Makefile delete mode 100644 net/x25/Kconfig