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Looks like it's essentially unused and has been replaced by better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>
After my patch there is CONFIG_ATA defined twice.
Remove the duplicate one.
Same problem for CONFIG_HAPPYMEAL, except I added as builtin for boot
test with NFS.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: a57cdeb369 ("sparc: sparc64_defconfig: add necessary configs for qemu")
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull sparc updates from David Miller:
"A host of mall cleanups and adjustments that have accumulated while I
was away, nothing major"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc: (26 commits)
sparc: make xchg() into a statement expression
sparc64: Use arch_validate_flags() to validate ADI flag
sparc32: Fix comparing pointer to 0 coccicheck warning
sparc: fix led.c driver when PROC_FS is not enabled
sparc: Fix handling of page table constructor failure
sparc64: only select COMPAT_BINFMT_ELF if BINFMT_ELF is set
tty: hvcs: Drop unnecessary if block
tty: vcc: Drop unnecessary if block
tty: vcc: Drop impossible to hit WARN_ON
sparc: sparc64_defconfig: add necessary configs for qemu
sparc64: switch defconfig from the legacy ide driver to libata
sparc32: Preserve clone syscall flags argument for restarts due to signals
sparc32: Limit memblock allocation to low memory
sparc: Replace test_ti_thread_flag() with test_tsk_thread_flag()
sbus: char: Remove meaningless jump label out_free
sparc32: signal: Fix stack trampoline for RT signals
sparc: remove SA_STATIC_ALLOC macro definition
sparc: use for_each_child_of_node() macro
sparc: Use fallthrough pseudo-keyword
sparc32: srmmu: improve type safety of __nocache_fix()
...
The sparc64 qemu machines uses sunhme network hardware by default, so for
simple NFS boot testing using qemu, having CONFIG_HAPPYMEAL is useful.
And so we need also IP_PNP_DHCP for NFS boot.
For the same reason we need to enable its storage which is a PATA_CMD64.
And finally, we need CONFIG_DEVTMPFS for handling recent udev/systemd.
All those options will permit to enable boot testing in both kernelCI
and gentoo's kernelCI.
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace the ide options with the equivalent libata options. This has
been carried by various downstreams like the linux-build-test repo
for years already.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The "oprofile" user-space tools don't use the kernel OPROFILE support
any more, and haven't in a long time. User-space has been converted to
the perf interfaces.
Remove the old oprofile's architecture specific support.
Suggested-by: Christoph Hellwig <hch@infradead.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Robert Richter <rric@kernel.org>
Acked-by: William Cohen <wcohen@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
This kernel configuration is basically enabling/disabling sr driver quirks
detection. While these quirks are for fairly rare devices (very old CD
burners, and a glucometer), the additional detection of these models is a
very minimal amount of code.
The logic behind the quirks is always built into the sr driver.
This also removes the config from all the defconfig files that are enabling
this already.
Link: https://lore.kernel.org/r/20200223191144.726-1-flameeyes@flameeyes.com
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Diego Elio Pettenò <flameeyes@flameeyes.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
This Kconfig option was removed during v4.19 development in commit
771c035372 ("deprecate the '__deprecated' attribute warnings entirely
and for good") so there's no point to keep it in defconfigs any longer.
FWIW defconfigs were patched with:
--------------------------->8----------------------
find . -name *_defconfig -exec sed -i '/CONFIG_ENABLE_WARN_DEPRECATED/d' {} \;
--------------------------->8----------------------
Link: http://lkml.kernel.org/r/20190128152434.41969-1-abrodkin@synopsys.com
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Enables the Virtual Console Concentrator (VCC) module
in linux kernel
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Remove old, dead Kconfig options (in order appearing in this commit):
- EXPERIMENTAL is gone since v3.9;
- INET_LRO: commit 7bbf3cae65 ("ipv4: Remove inet_lro library");
- AUTOFS_FS: commit 561c5cf923 ("staging: Remove autofs3");
- RCU_CPU_STALL_DETECTOR: commit a00e0d714f ("rcu: Remove conditional
compilation for RCU CPU stall warnings");
- USB_DEVICE_CLASS: commit 007bab9132 ("USB: remove
CONFIG_USB_DEVICE_CLASS");
- SYSCTL_SYSCALL_CHECK: commit 7c60c48f58 ("sysctl: Improve the
sysctl sanity checks");
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Eric Saint Etienne <eric.saint.etienne@oracle.com>
Signed-off-by: Allen Pais <allen.pais@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Option is long gone, see
5d9efa7ee9 ("ipv6: Remove privacy config option.")
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: sparclinux@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Add ldmvsw.c driver
Details:
The ldmvsw driver very closely follows the sunvnet.c code and makes
use of the sunvnet_common.c code for core functionality.
A significant difference between sunvnet and ldmvsw driver is
sunvnet creates a network interface for each vnet-port *parent*
node in the MD while the ldmvsw driver creates a network interface
for every vsw-port node in the Machine Description (MD).
Therefore the netdev_priv() for sunvnet is a vnet structure while
the netdev_priv() for ldmvsw is a vnet_port structure.
Vnet_port structures allocated by ldmvsw have the vsw bit set.
When finding the net_device associated with a port, the common code keys
off this bit to use either the net_device found in the vnet_port or the
net_device in the vnet structure (see the VNET_PORT_TO_NET_DEVICE() macro in
sunvnet_common.h). This scheme allows the common code to work with
both drivers with minimal changes.
Similar to Xen, network interfaces created by the ldmvsw driver will always
have a HW Addr (i.e. mac address) of FE:FF:FF:FF:FF:FF and each will be
assigned the devname "vif<cfg_handle>.<port_id>" - where <cfg_handle> and
<port_id> are a unique handle/port pair assigned to the associated
vsw-port node in the MD.
Signed-off-by: Aaron Young <aaron.young@oracle.com>
Signed-off-by: Rashmi Narasimhan <rashmi.narasimhan@oracle.com>
Reviewed-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Reviewed-by: Alexandre Chartre <Alexandre.Chartre@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 5d6be6a5 ("scsi_netlink : Make SCSI_NETLINK dependent on NET
instead of selecting NET") removed what happened to be the only instance
of 'select NET'. Defconfigs that were relying on the select now lack
networking support.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: sparclinux@vger.kernel.org
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Renaming remaining PERF_COUNTERS options into PERF_EVENTS.
Think we can get rid of PERF_COUNTERS now.
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1333643084-26776-5-git-send-email-robert.richter@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Move from SLUB to SLAB, as this is what the world plans to align
to, every distribution enables, and thus is what everyone actually
is testing.
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
To unify Makefile for sparc and sparc64 a few other steps was needed:
1) separate defconfig files for sparc and sparc64 is required,
so locate these in arch/sparc/configs
2) removoval of hack in toplevel Makefile to deal with that
headers was in a separate directory compared to the rest
The unification of the Makefile required usage of several
foo-$(CONFIG_SPARCnn) +=
due to a few directories pending unification.
This will be cleaned up when we unify the remaining directories.
Included in this patch are the deletion of a few files in
sparc64 as they are no longer needed: Makefile + Kconfig.
arch/sparc64/ will after this patch is applied only
have four directories (prom, lib, kernel, boot)
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
David Hildenbrand