Patch series "drivers/char: remove /dev/kmem for good".
Exploring /dev/kmem and /dev/mem in the context of memory hot(un)plug and
memory ballooning, I started questioning the existence of /dev/kmem.
Comparing it with the /proc/kcore implementation, it does not seem to be
able to deal with things like
a) Pages unmapped from the direct mapping (e.g., to be used by secretmem)
-> kern_addr_valid(). virt_addr_valid() is not sufficient.
b) Special cases like gart aperture memory that is not to be touched
-> mem_pfn_is_ram()
Unless I am missing something, it's at least broken in some cases and might
fault/crash the machine.
Looks like its existence has been questioned before in 2005 and 2010 [1],
after ~11 additional years, it might make sense to revive the discussion.
CONFIG_DEVKMEM is only enabled in a single defconfig (on purpose or by
mistake?). All distributions disable it: in Ubuntu it has been disabled
for more than 10 years, in Debian since 2.6.31, in Fedora at least
starting with FC3, in RHEL starting with RHEL4, in SUSE starting from
15sp2, and OpenSUSE has it disabled as well.
1) /dev/kmem was popular for rootkits [2] before it got disabled
basically everywhere. Ubuntu documents [3] "There is no modern user of
/dev/kmem any more beyond attackers using it to load kernel rootkits.".
RHEL documents in a BZ [5] "it served no practical purpose other than to
serve as a potential security problem or to enable binary module drivers
to access structures/functions they shouldn't be touching"
2) /proc/kcore is a decent interface to have a controlled way to read
kernel memory for debugging puposes. (will need some extensions to
deal with memory offlining/unplug, memory ballooning, and poisoned
pages, though)
3) It might be useful for corner case debugging [1]. KDB/KGDB might be a
better fit, especially, to write random memory; harder to shoot
yourself into the foot.
4) "Kernel Memory Editor" [4] hasn't seen any updates since 2000 and seems
to be incompatible with 64bit [1]. For educational purposes,
/proc/kcore might be used to monitor value updates -- or older
kernels can be used.
5) It's broken on arm64, and therefore, completely disabled there.
Looks like it's essentially unused and has been replaced by better
suited interfaces for individual tasks (/proc/kcore, KDB/KGDB). Let's
just remove it.
[1] https://lwn.net/Articles/147901/
[2] https://www.linuxjournal.com/article/10505
[3] https://wiki.ubuntu.com/Security/Features#A.2Fdev.2Fkmem_disabled
[4] https://sourceforge.net/projects/kme/
[5] https://bugzilla.redhat.com/show_bug.cgi?id=154796
Link: https://lkml.kernel.org/r/20210324102351.6932-1-david@redhat.com
Link: https://lkml.kernel.org/r/20210324102351.6932-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Alexander A. Klimov" <grandmaster@al2klimov.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Andrey Zhizhikin <andrey.zhizhikin@leica-geosystems.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Chris Zankel <chris@zankel.net>
Cc: Corentin Labbe <clabbe@baylibre.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Gregory Clement <gregory.clement@bootlin.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Hillf Danton <hdanton@sina.com>
Cc: huang ying <huang.ying.caritas@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: James Troup <james.troup@canonical.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kairui Song <kasong@redhat.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: openrisc@lists.librecores.org
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Pavel Machek (CIP)" <pavel@denx.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Pierre Morel <pmorel@linux.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: sparclinux@vger.kernel.org
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Theodore Dubois <tblodt@icloud.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: William Cohen <wcohen@redhat.com>
Cc: Xiaoming Ni <nixiaoming@huawei.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 7ecdea4a02 ("backlight: generic_bl: Remove this driver as it is
unused") removed geenric_bl driver from the tree, together with
corresponding config option.
Remove BACKLIGHT_GENERIC config item from all ARM configurations.
Fixes: 7ecdea4a02 ("backlight: generic_bl: Remove this driver as it is unused")
Signed-off-by: Andrey Zhizhikin <andrey.zhizhikin@leica-geosystems.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Link: https://lore.kernel.org/r/20201201222922.3183-2-andrey.zhizhikin@leica-geosystems.com'
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
CONFIG_MMC_BLOCK_BOUNCE is gone since commit c3dccb74be ("mmc: core:
Delete bounce buffer Kconfig option").
CONFIG_LBDAF is gone since commit 72deb455b5 ("block: remove
CONFIG_LBDAF").
CONFIG_IOSCHED_DEADLINE and CONFIG_IOSCHED_CFQ are gone since
commit f382fb0bce ("block: remove legacy IO schedulers").
The IOSCHED_DEADLINE was replaced by MQ_IOSCHED_DEADLINE and it will be
now enabled by default (along with MQ_IOSCHED_KYBER).
The IOSCHED_BFQ seems to replace IOSCHED_CFQ so select it in configs
previously choosing the latter.
CONFIG_CROSS_COMPILE is gone since commit f1089c92da ("kbuild: remove
CONFIG_CROSS_COMPILE support").
Link: https://lore.kernel.org/r/20200130195525.4525-2-krzk@kernel.org
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Olof Johansson <olof@lixom.net>
Remove the CONFIG_UEVENT_HELPER_PATH because:
1. It is disabled since commit 1be01d4a57 ("driver: base: Disable
CONFIG_UEVENT_HELPER by default") as its dependency (UEVENT_HELPER) was
made default to 'n',
2. It is not recommended (help message: "This should not be used today
[...] creates a high system load") and was kept only for ancient
userland,
3. Certain userland specifically requests it to be disabled (systemd
README: "Legacy hotplug slows down the system and confuses udev").
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Andrew Jeffery <andrew@aj.id.au>
Acked-by: Shawn Guo <shawnguo@kernel.org>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
The CONFIG_BACKLIGHT_LCD_SUPPORT was removed in commit 8c5dc8d9f1
("video: backlight: Remove useless BACKLIGHT_LCD_SUPPORT kernel
symbol"). Options protected by CONFIG_BACKLIGHT_LCD_SUPPORT are now
available directly.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
It doesn't actually do anything. Merge its help text into
EXTRA_FIRMWARE.
Fixes: 5620a0d1aa ("firmware: delete in-kernel firmware")
Fixes: 0946b2fb38 ("firmware: cleanup FIRMWARE_IN_KERNEL message")
Signed-off-by: Benjamin Gilbert <benjamin.gilbert@coreos.com>
Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With the SA1100 and PXA RTC drivers be mutually exclusive and no
longer sharing hardware, PXA27x/PXA3xx platforms must use the PXA RTC
driver as the SA1100 platform device is no longer registered.
This change should be almost transparent to userspace. Former users of
pxa-rtc should be aware that 2 RTCs will be available on their kernels,
rtc0 being sa1100-rtc and rtc1 being pxa-rtc. Any userspace relying on
the fact that rtc0 was pxa-rtc should be fixed.
As a consequence:
- the first reboot after the switch will have the wrong time,
- on dual boot platform where the other OS programs some logic into the
sa1100 rtc IP, a lack of fix in userspace, ie. a kernel changing
sa1100-rtc thinking it is pxa-rtc could have dire consequence, such
as wiping the other OS data partition.
(Thanks to Robert Jarmik for help on the above commit text.)
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Daniel Mack <daniel@zonque.org>
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: Sergey Lapin <slapin@ossfans.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Mike Rapoport <mike@compulab.co.il>
Cc: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
The File-backed Storage Gadget (g_file_storage) is being removed, since
it has been replaced by Mass Storage Gadget (g_mass_storage). This commit
changes defconfigs point to the new gadget.
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> (AT91)
Acked-by: Tony Lindgren <tony@atomide.com> (OMAP1)
Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no> (AVR32)
Signed-off-by: Felipe Balbi <balbi@ti.com>
The bq24022 on these machines is a very simple regulator using gpios.
One provides the on/off functionality and a second one is used to
change the current between 100 and 500 mA.
This functionality can also be provided by the more generic gpio-regulator.
Therefore convert both machines which makes it possible to remove the
bq24022 driver later on.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Paul Parsons <lost.distance@yahoo.com>
Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Since CONFIG_USB_GADGET_PXA27X and other macros are renamed to
CONFIG_USB_PXA27X. Update them in arch/arm/mach-pxa and arch/arm/configs
to keep consistent.
Cc: stable@kernel.org
Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option
is used to configure any non-standard kernel with a much larger scope than
only small devices.
This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes
references to the option throughout the kernel. A new CONFIG_EMBEDDED
option is added that automatically selects CONFIG_EXPERT when enabled and
can be used in the future to isolate options that should only be
considered for embedded systems (RISC architectures, SLOB, etc).
Calling the option "EXPERT" more accurately represents its intention: only
expert users who understand the impact of the configuration changes they
are making should enable it.
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: David Woodhouse <david.woodhouse@intel.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Greg KH <gregkh@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Robin Holt <holt@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
26-bit ARM support was removed a long time ago, and this symbol has
been defined to be 'y' ever since. As it's never disabled anymore,
we can kill it without any side effects.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
I'm not going to maintain separate defconfigs for magician and hx4700.
This should probably be renamed to htcpxa_defconfig.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Eric Miao <eric.miao@marvell.com>
With this patch, the bq24022 battery charger is controlled by the USB
gadget framework (via gpio_vbus) when connected to USB.
To compile, this patch depends on the "regulator: Allow init data to be
supplied for bq24022" patch (queued for next in the regulator tree) to
add the init_data field to struct bq24022_mach_info.
It also depends on the "add optional OTG transceiver and voltage
regulator support to pda_power" patch (queued for next in the power
supply tree) to enable charging when connected to the AC charger.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Eric Miao <eric.miao@marvell.com>
This patch depends on otg_transceiver support in pxa27x_udc
(which is queued via linux-usb) to work.
It compiles also without it.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Eric Miao <eric.miao@marvell.com>
Now that all EEPROM drivers live in the same place, let's harmonize
their symbol names.
Also fix eeprom's dependencies, it definitely needs sysfs, and is no
longer experimental after many years in the kernel tree.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Magician uses the generic PWM backlight driver,
so select HAVE_PWM.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Eric Miao <eric.miao@marvell.com>
This is the touched up result of make magician_defconfig in 2.6.29-rc2.
- Enabled USB host and bluetooth: magician has a CSR BlueCore3 connected
to the PXA27x OHCI internally.
- Made I2C built-in.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Eric Miao <eric.miao@marvell.com>
This patch enables LEDs and the 1-wire bus (connected to
a DS2760 battery monitor) on the magician.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This enables rootfs on StrataFlash if the bootloader supplies the
partition list.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
needed for power management (audio, BT, charging, GSM, LCD, SD), GSM, flash and SD operation and audio routing.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
David Hildenbrand
Andrey Zhizhikin
Krzysztof Kozlowski
Benjamin Gilbert
Rob Herring
Michal Nazarewicz
Heiko Stübner
Haojian Zhuang
David Rientjes
Uwe Kleine-König
Russell King
Philipp Zabel
Russell King
Jean Delvare