History log of /linux-6.15/drivers/char/Kconfig (Results 1 – 25 of 248)
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Revision tags: v6.15, v6.15-rc7, v6.15-rc6, v6.15-rc5, v6.15-rc4, v6.15-rc3, v6.15-rc2, v6.15-rc1, v6.14, v6.14-rc7, v6.14-rc6, v6.14-rc5, v6.14-rc4, v6.14-rc3, v6.14-rc2, v6.14-rc1, v6.13, v6.13-rc7, v6.13-rc6, v6.13-rc5, v6.13-rc4, v6.13-rc3, v6.13-rc2, v6.13-rc1, v6.12, v6.12-rc7, v6.12-rc6, v6.12-rc5, v6.12-rc4, v6.12-rc3
# a6021aa2 11-Oct-2024 Arnd Bergmann <[email protected]>

ACPI: EC: make EC support compile-time conditional

The embedded controller code is mainly used on x86 laptops and cannot
work without PC style I/O port access.

Make this a user-visible configuratio

ACPI: EC: make EC support compile-time conditional

The embedded controller code is mainly used on x86 laptops and cannot
work without PC style I/O port access.

Make this a user-visible configuration option that is default enabled
on x86 but otherwise disabled, and that can never be enabled unless
CONFIG_HAS_IOPORT is also available.

The empty stubs in internal.h help ignore the EC code in configurations
that don't support it. In order to see those stubs, the sbshc code also
has to include this header and drop duplicate declarations.

All the direct callers of ec_read/ec_write already had an x86
dependency and now also need to depend on APCI_EC.

Signed-off-by: Arnd Bergmann <[email protected]>
Acked-by: Guenter Roeck <[email protected]>
Acked-by: Hans de Goede <[email protected]>
Link: https://patch.msgid.link/[email protected]
[ rjw: Subject edits ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

show more ...


Revision tags: v6.12-rc2, v6.12-rc1, v6.11, v6.11-rc7, v6.11-rc6, v6.11-rc5, v6.11-rc4, v6.11-rc3, v6.11-rc2, v6.11-rc1, v6.10, v6.10-rc7, v6.10-rc6, v6.10-rc5, v6.10-rc4, v6.10-rc3, v6.10-rc2, v6.10-rc1, v6.9, v6.9-rc7, v6.9-rc6, v6.9-rc5, v6.9-rc4, v6.9-rc3, v6.9-rc2, v6.9-rc1, v6.8, v6.8-rc7, v6.8-rc6, v6.8-rc5, v6.8-rc4, v6.8-rc3, v6.8-rc2, v6.8-rc1, v6.7, v6.7-rc8, v6.7-rc7, v6.7-rc6, v6.7-rc5, v6.7-rc4, v6.7-rc3, v6.7-rc2, v6.7-rc1, v6.6, v6.6-rc7, v6.6-rc6, v6.6-rc5, v6.6-rc4, v6.6-rc3, v6.6-rc2, v6.6-rc1, v6.5, v6.5-rc7, v6.5-rc6, v6.5-rc5, v6.5-rc4, v6.5-rc3, v6.5-rc2, v6.5-rc1, v6.4, v6.4-rc7, v6.4-rc6, v6.4-rc5, v6.4-rc4, v6.4-rc3, v6.4-rc2, v6.4-rc1, v6.3, v6.3-rc7, v6.3-rc6, v6.3-rc5, v6.3-rc4, v6.3-rc3, v6.3-rc2, v6.3-rc1, v6.2, v6.2-rc8, v6.2-rc7, v6.2-rc6, v6.2-rc5, v6.2-rc4, v6.2-rc3, v6.2-rc2, v6.2-rc1, v6.1, v6.1-rc8, v6.1-rc7, v6.1-rc6, v6.1-rc5, v6.1-rc4, v6.1-rc3, v6.1-rc2
# cf8e8658 20-Oct-2022 Ard Biesheuvel <[email protected]>

arch: Remove Itanium (IA-64) architecture

The Itanium architecture is obsolete, and an informal survey [0] reveals
that any residual use of Itanium hardware in production is mostly HP-UX
or OpenVMS

arch: Remove Itanium (IA-64) architecture

The Itanium architecture is obsolete, and an informal survey [0] reveals
that any residual use of Itanium hardware in production is mostly HP-UX
or OpenVMS based. The use of Linux on Itanium appears to be limited to
enthusiasts that occasionally boot a fresh Linux kernel to see whether
things are still working as intended, and perhaps to churn out some
distro packages that are rarely used in practice.

None of the original companies behind Itanium still produce or support
any hardware or software for the architecture, and it is listed as
'Orphaned' in the MAINTAINERS file, as apparently, none of the engineers
that contributed on behalf of those companies (nor anyone else, for that
matter) have been willing to support or maintain the architecture
upstream or even be responsible for applying the odd fix. The Intel
firmware team removed all IA-64 support from the Tianocore/EDK2
reference implementation of EFI in 2018. (Itanium is the original
architecture for which EFI was developed, and the way Linux supports it
deviates significantly from other architectures.) Some distros, such as
Debian and Gentoo, still maintain [unofficial] ia64 ports, but many have
dropped support years ago.

While the argument is being made [1] that there is a 'for the common
good' angle to being able to build and run existing projects such as the
Grid Community Toolkit [2] on Itanium for interoperability testing, the
fact remains that none of those projects are known to be deployed on
Linux/ia64, and very few people actually have access to such a system in
the first place. Even if there were ways imaginable in which Linux/ia64
could be put to good use today, what matters is whether anyone is
actually doing that, and this does not appear to be the case.

There are no emulators widely available, and so boot testing Itanium is
generally infeasible for ordinary contributors. GCC still supports IA-64
but its compile farm [3] no longer has any IA-64 machines. GLIBC would
like to get rid of IA-64 [4] too because it would permit some overdue
code cleanups. In summary, the benefits to the ecosystem of having IA-64
be part of it are mostly theoretical, whereas the maintenance overhead
of keeping it supported is real.

So let's rip off the band aid, and remove the IA-64 arch code entirely.
This follows the timeline proposed by the Debian/ia64 maintainer [5],
which removes support in a controlled manner, leaving IA-64 in a known
good state in the most recent LTS release. Other projects will follow
once the kernel support is removed.

[0] https://lore.kernel.org/all/CAMj1kXFCMh_578jniKpUtx_j8ByHnt=s7S+yQ+vGbKt9ud7+kQ@mail.gmail.com/
[1] https://lore.kernel.org/all/[email protected]/
[2] https://gridcf.org/gct-docs/latest/index.html
[3] https://cfarm.tetaneutral.net/machines/list/
[4] https://lore.kernel.org/all/[email protected]/
[5] https://lore.kernel.org/all/ff58a3e76e5102c94bb5946d99187b358def688a.camel@physik.fu-berlin.de/

Acked-by: Tony Luck <[email protected]>
Signed-off-by: Ard Biesheuvel <[email protected]>

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# 1fbb0b20 22-May-2023 Niklas Schnelle <[email protected]>

char: add HAS_IOPORT dependencies

In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
not being declared. We thus need to add HAS_IOPORT as dependency for
those drivers using them

char: add HAS_IOPORT dependencies

In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
not being declared. We thus need to add HAS_IOPORT as dependency for
those drivers using them.

Co-developed-by: Arnd Bergmann <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Niklas Schnelle <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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# 9b12f050 22-Feb-2023 Jiri Slaby <[email protected]>

char: pcmcia: remove all the drivers

These char PCMCIA drivers are buggy[1] and receive only minimal care. It
was concluded[2], that we should try to remove most pcmcia drivers
completely. Let's sta

char: pcmcia: remove all the drivers

These char PCMCIA drivers are buggy[1] and receive only minimal care. It
was concluded[2], that we should try to remove most pcmcia drivers
completely. Let's start with these char broken one.

Note that I also removed a UAPI header: include/uapi/linux/cm4000_cs.h.
I found only coccinelle tests mentioning some ioctl constants from that
file. But they are not actually used. Anyway, should someone complain,
we may reintroduce the header (or its parts).

[1] https://lore.kernel.org/all/[email protected]/
[2] https://lore.kernel.org/all/[email protected]/

Signed-off-by: Jiri Slaby (SUSE) <[email protected]>
Cc: "Hyunwoo Kim" <[email protected]>
Cc: Harald Welte <[email protected]>
Cc: Lubomir Rintel <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Acked-by: Dominik Brodowski <[email protected]>
Reviewed-by: Arnd Bergmann <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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# b9b01a56 01-Nov-2022 Jason A. Donenfeld <[email protected]>

random: use random.trust_{bootloader,cpu} command line option only

It's very unusual to have both a command line option and a compile time
option, and apparently that's confusing to people. Also, ba

random: use random.trust_{bootloader,cpu} command line option only

It's very unusual to have both a command line option and a compile time
option, and apparently that's confusing to people. Also, basically
everybody enables the compile time option now, which means people who
want to disable this wind up having to use the command line option to
ensure that anyway. So just reduce the number of moving pieces and nix
the compile time option in favor of the more versatile command line
option.

Signed-off-by: Jason A. Donenfeld <[email protected]>

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Revision tags: v6.1-rc1, v6.0, v6.0-rc7, v6.0-rc6, v6.0-rc5, v6.0-rc4, v6.0-rc3, v6.0-rc2, v6.0-rc1, v5.19, v5.19-rc8, v5.19-rc7
# 1208ec59 16-Jul-2022 Thomas Bogendoerfer <[email protected]>

char: remove VR41XX related char driver

Commit d3164e2f3b0a ("MIPS: Remove VR41xx support") removed support
for MIPS VR41xx platform, so remove exclusive drivers for this
platform, too.

Signed-off-

char: remove VR41XX related char driver

Commit d3164e2f3b0a ("MIPS: Remove VR41xx support") removed support
for MIPS VR41xx platform, so remove exclusive drivers for this
platform, too.

Signed-off-by: Thomas Bogendoerfer <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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Revision tags: v5.19-rc6
# 9592eef7 05-Jul-2022 Jason A. Donenfeld <[email protected]>

random: remove CONFIG_ARCH_RANDOM

When RDRAND was introduced, there was much discussion on whether it
should be trusted and how the kernel should handle that. Initially, two
mechanisms cropped up, C

random: remove CONFIG_ARCH_RANDOM

When RDRAND was introduced, there was much discussion on whether it
should be trusted and how the kernel should handle that. Initially, two
mechanisms cropped up, CONFIG_ARCH_RANDOM, a compile time switch, and
"nordrand", a boot-time switch.

Later the thinking evolved. With a properly designed RNG, using RDRAND
values alone won't harm anything, even if the outputs are malicious.
Rather, the issue is whether those values are being *trusted* to be good
or not. And so a new set of options were introduced as the real
ones that people use -- CONFIG_RANDOM_TRUST_CPU and "random.trust_cpu".
With these options, RDRAND is used, but it's not always credited. So in
the worst case, it does nothing, and in the best case, maybe it helps.

Along the way, CONFIG_ARCH_RANDOM's meaning got sort of pulled into the
center and became something certain platforms force-select.

The old options don't really help with much, and it's a bit odd to have
special handling for these instructions when the kernel can deal fine
with the existence or untrusted existence or broken existence or
non-existence of that CPU capability.

Simplify the situation by removing CONFIG_ARCH_RANDOM and using the
ordinary asm-generic fallback pattern instead, keeping the two options
that are actually used. For now it leaves "nordrand" for now, as the
removal of that will take a different route.

Acked-by: Michael Ellerman <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Acked-by: Borislav Petkov <[email protected]>
Acked-by: Heiko Carstens <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Jason A. Donenfeld <[email protected]>

show more ...


Revision tags: v5.19-rc5, v5.19-rc4, v5.19-rc3, v5.19-rc2, v5.19-rc1
# 846bb97e 05-Jun-2022 Jason A. Donenfeld <[email protected]>

random: credit cpu and bootloader seeds by default

This commit changes the default Kconfig values of RANDOM_TRUST_CPU and
RANDOM_TRUST_BOOTLOADER to be Y by default. It does not change any
existing

random: credit cpu and bootloader seeds by default

This commit changes the default Kconfig values of RANDOM_TRUST_CPU and
RANDOM_TRUST_BOOTLOADER to be Y by default. It does not change any
existing configs or change any kernel behavior. The reason for this is
several fold.

As background, I recently had an email thread with the kernel
maintainers of Fedora/RHEL, Debian, Ubuntu, Gentoo, Arch, NixOS, Alpine,
SUSE, and Void as recipients. I noted that some distros trust RDRAND,
some trust EFI, and some trust both, and I asked why or why not. There
wasn't really much of a "debate" but rather an interesting discussion of
what the historical reasons have been for this, and it came up that some
distros just missed the introduction of the bootloader Kconfig knob,
while another didn't want to enable it until there was a boot time
switch to turn it off for more concerned users (which has since been
added). The result of the rather uneventful discussion is that every
major Linux distro enables these two options by default.

While I didn't have really too strong of an opinion going into this
thread -- and I mostly wanted to learn what the distros' thinking was
one way or another -- ultimately I think their choice was a decent
enough one for a default option (which can be disabled at boot time).
I'll try to summarize the pros and cons:

Pros:

- The RNG machinery gets initialized super quickly, and there's no
messing around with subsequent blocking behavior.

- The bootloader mechanism is used by kexec in order for the prior
kernel to initialize the RNG of the next kernel, which increases
the entropy available to early boot daemons of the next kernel.

- Previous objections related to backdoors centered around
Dual_EC_DRBG-like kleptographic systems, in which observing some
amount of the output stream enables an adversary holding the right key
to determine the entire output stream.

This used to be a partially justified concern, because RDRAND output
was mixed into the output stream in varying ways, some of which may
have lacked pre-image resistance (e.g. XOR or an LFSR).

But this is no longer the case. Now, all usage of RDRAND and
bootloader seeds go through a cryptographic hash function. This means
that the CPU would have to compute a hash pre-image, which is not
considered to be feasible (otherwise the hash function would be
terribly broken).

- More generally, if the CPU is backdoored, the RNG is probably not the
realistic vector of choice for an attacker.

- These CPU or bootloader seeds are far from being the only source of
entropy. Rather, there is generally a pretty huge amount of entropy,
not all of which is credited, especially on CPUs that support
instructions like RDRAND. In other words, assuming RDRAND outputs all
zeros, an attacker would *still* have to accurately model every single
other entropy source also in use.

- The RNG now reseeds itself quite rapidly during boot, starting at 2
seconds, then 4, then 8, then 16, and so forth, so that other sources
of entropy get used without much delay.

- Paranoid users can set random.trust_{cpu,bootloader}=no in the kernel
command line, and paranoid system builders can set the Kconfig options
to N, so there's no reduction or restriction of optionality.

- It's a practical default.

- All the distros have it set this way. Microsoft and Apple trust it
too. Bandwagon.

Cons:

- RDRAND *could* still be backdoored with something like a fixed key or
limited space serial number seed or another indexable scheme like
that. (However, it's hard to imagine threat models where the CPU is
backdoored like this, yet people are still okay making *any*
computations with it or connecting it to networks, etc.)

- RDRAND *could* be defective, rather than backdoored, and produce
garbage that is in one way or another insufficient for crypto.

- Suggesting a *reduction* in paranoia, as this commit effectively does,
may cause some to question my personal integrity as a "security
person".

- Bootloader seeds and RDRAND are generally very difficult if not all
together impossible to audit.

Keep in mind that this doesn't actually change any behavior. This
is just a change in the default Kconfig value. The distros already are
shipping kernels that set things this way.

Ard made an additional argument in [1]:

We're at the mercy of firmware and micro-architecture anyway, given
that we are also relying on it to ensure that every instruction in
the kernel's executable image has been faithfully copied to memory,
and that the CPU implements those instructions as documented. So I
don't think firmware or ISA bugs related to RNGs deserve special
treatment - if they are broken, we should quirk around them like we
usually do. So enabling these by default is a step in the right
direction IMHO.

In [2], Phil pointed out that having this disabled masked a bug that CI
otherwise would have caught:

A clean 5.15.45 boots cleanly, whereas a downstream kernel shows the
static key warning (but it does go on to boot). The significant
difference is that our defconfigs set CONFIG_RANDOM_TRUST_BOOTLOADER=y
defining that on top of multi_v7_defconfig demonstrates the issue on
a clean 5.15.45. Conversely, not setting that option in a
downstream kernel build avoids the warning

[1] https://lore.kernel.org/lkml/CAMj1kXGi+ieviFjXv9zQBSaGyyzeGW_VpMpTLJK8PJb2QHEQ-w@mail.gmail.com/
[2] https://lore.kernel.org/lkml/[email protected]/

Cc: Theodore Ts'o <[email protected]>
Reviewed-by: Ard Biesheuvel <[email protected]>
Signed-off-by: Jason A. Donenfeld <[email protected]>

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Revision tags: v5.18, v5.18-rc7, v5.18-rc6, v5.18-rc5, v5.18-rc4, v5.18-rc3, v5.18-rc2, v5.18-rc1, v5.17, v5.17-rc8, v5.17-rc7, v5.17-rc6, v5.17-rc5
# 7ea4aa70 15-Feb-2022 Vincent Whitchurch <[email protected]>

char: ttyprintk: register console

Register a console in the ttyprintk driver so that it can be selected
for /dev/console with console=ttyprintk on the kernel command line,
similar to other console d

char: ttyprintk: register console

Register a console in the ttyprintk driver so that it can be selected
for /dev/console with console=ttyprintk on the kernel command line,
similar to other console drivers.

Signed-off-by: Vincent Whitchurch <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...


# d97c68d1 23-Mar-2022 Jason A. Donenfeld <[email protected]>

random: treat bootloader trust toggle the same way as cpu trust toggle

If CONFIG_RANDOM_TRUST_CPU is set, the RNG initializes using RDRAND.
But, the user can disable (or enable) this behavior by set

random: treat bootloader trust toggle the same way as cpu trust toggle

If CONFIG_RANDOM_TRUST_CPU is set, the RNG initializes using RDRAND.
But, the user can disable (or enable) this behavior by setting
`random.trust_cpu=0/1` on the kernel command line. This allows system
builders to do reasonable things while avoiding howls from tinfoil
hatters. (Or vice versa.)

CONFIG_RANDOM_TRUST_BOOTLOADER is basically the same thing, but regards
the seed passed via EFI or device tree, which might come from RDRAND or
a TPM or somewhere else. In order to allow distros to more easily enable
this while avoiding those same howls (or vice versa), this commit adds
the corresponding `random.trust_bootloader=0/1` toggle.

Cc: Theodore Ts'o <[email protected]>
Cc: Graham Christensen <[email protected]>
Reviewed-by: Ard Biesheuvel <[email protected]>
Reviewed-by: Dominik Brodowski <[email protected]>
Link: https://github.com/NixOS/nixpkgs/pull/165355
Signed-off-by: Jason A. Donenfeld <[email protected]>

show more ...


Revision tags: v5.17-rc4, v5.17-rc3, v5.17-rc2, v5.17-rc1, v5.16, v5.16-rc8, v5.16-rc7, v5.16-rc6, v5.16-rc5, v5.16-rc4, v5.16-rc3, v5.16-rc2, v5.16-rc1, v5.15, v5.15-rc7, v5.15-rc6, v5.15-rc5, v5.15-rc4, v5.15-rc3, v5.15-rc2, v5.15-rc1, v5.14, v5.14-rc7
# 9e1b28b7 16-Aug-2021 Randy Dunlap <[email protected]>

char: move RANDOM_TRUST_CPU & RANDOM_TRUST_BOOTLOADER into the Character devices menu

Include RANDOM_TRUST_CPU and RANDOM_TRUST_BOOTLOADER inside the
"Character devices" menu so that they are listed

char: move RANDOM_TRUST_CPU & RANDOM_TRUST_BOOTLOADER into the Character devices menu

Include RANDOM_TRUST_CPU and RANDOM_TRUST_BOOTLOADER inside the
"Character devices" menu so that they are listed (presented)
with other Character devices.

Cc: Arnd Bergmann <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Hsin-Yi Wang <[email protected]>
Cc: Theodore Ts'o <[email protected]>
Signed-off-by: Randy Dunlap <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...


Revision tags: v5.14-rc6, v5.14-rc5, v5.14-rc4, v5.14-rc3, v5.14-rc2, v5.14-rc1, v5.13, v5.13-rc7, v5.13-rc6, v5.13-rc5
# 603e4922 31-May-2021 Christoph Hellwig <[email protected]>

remove the raw driver

The raw driver used to provide direct unbuffered access to block devices
before O_DIRECT was invented. It has been obsolete for more than a
decade.

Acked-by: Greg Kroah-Hartm

remove the raw driver

The raw driver used to provide direct unbuffered access to block devices
before O_DIRECT was invented. It has been obsolete for more than a
decade.

Acked-by: Greg Kroah-Hartman <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Link: https://lore.kernel.org/lkml/Pine.LNX.4.64.0703180754060.6605@CPE00045a9c397f-CM001225dbafb6/
Signed-off-by: Christoph Hellwig <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...


Revision tags: v5.13-rc4, v5.13-rc3, v5.13-rc2, v5.13-rc1
# ed5aecd3 05-May-2021 Jiri Slaby <[email protected]>

tty: remove broken r3964 line discipline

Noone stepped up in the past two years since it was marked as BROKEN by
commit c7084edc3f6d (tty: mark Siemens R3964 line discipline as BROKEN).
Remove the l

tty: remove broken r3964 line discipline

Noone stepped up in the past two years since it was marked as BROKEN by
commit c7084edc3f6d (tty: mark Siemens R3964 line discipline as BROKEN).
Remove the line discipline for good.

Three remarks:
* we remove also the uapi header (as noone is able to use that interface
anyway)
* we do *not* remove the N_R3964 constant definition from tty.h, so it
remains reserved.
* in_interrupt() check is now removed from vt's con_put_char. Noone else
calls tty_operations::put_char from interrupt context.

Signed-off-by: Jiri Slaby <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...


# bbcd53c9 07-May-2021 David Hildenbrand <[email protected]>

drivers/char: remove /dev/kmem for good

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 starte

drivers/char: remove /dev/kmem for good

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/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Acked-by: Kees Cook <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: "Alexander A. Klimov" <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Alexandre Belloni <[email protected]>
Cc: Andrew Lunn <[email protected]>
Cc: Andrey Zhizhikin <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Brian Cain <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Chris Zankel <[email protected]>
Cc: Corentin Labbe <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Greentime Hu <[email protected]>
Cc: Gregory Clement <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Hillf Danton <[email protected]>
Cc: huang ying <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Ivan Kokshaysky <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: James Troup <[email protected]>
Cc: Jiaxun Yang <[email protected]>
Cc: Jonas Bonn <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Kairui Song <[email protected]>
Cc: Krzysztof Kozlowski <[email protected]>
Cc: Kuninori Morimoto <[email protected]>
Cc: Liviu Dudau <[email protected]>
Cc: Lorenzo Pieralisi <[email protected]>
Cc: Luc Van Oostenryck <[email protected]>
Cc: Luis Chamberlain <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Max Filippov <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Mikulas Patocka <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Niklas Schnelle <[email protected]>
Cc: Oleksiy Avramchenko <[email protected]>
Cc: [email protected]
Cc: Palmer Dabbelt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: "Pavel Machek (CIP)" <[email protected]>
Cc: Pavel Machek <[email protected]>
Cc: "Peter Zijlstra (Intel)" <[email protected]>
Cc: Pierre Morel <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Robert Richter <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Russell King <[email protected]>
Cc: Sam Ravnborg <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Sebastian Hesselbarth <[email protected]>
Cc: [email protected]
Cc: Stafford Horne <[email protected]>
Cc: Stefan Kristiansson <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Sudeep Holla <[email protected]>
Cc: Theodore Dubois <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Viresh Kumar <[email protected]>
Cc: William Cohen <[email protected]>
Cc: Xiaoming Ni <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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Revision tags: v5.12, v5.12-rc8, v5.12-rc7, v5.12-rc6, v5.12-rc5, v5.12-rc4, v5.12-rc3, v5.12-rc2, v5.12-rc1, v5.12-rc1-dontuse, v5.11, v5.11-rc7, v5.11-rc6, v5.11-rc5, v5.11-rc4, v5.11-rc3, v5.11-rc2, v5.11-rc1, v5.10, v5.10-rc7, v5.10-rc6, v5.10-rc5, v5.10-rc4, v5.10-rc3, v5.10-rc2, v5.10-rc1, v5.9, v5.9-rc8, v5.9-rc7, v5.9-rc6, v5.9-rc5, v5.9-rc4
# 9f30eb29 31-Aug-2020 Michal Suchanek <[email protected]>

char: virtio: Select VIRTIO from VIRTIO_CONSOLE.

Make it possible to have virtio console built-in when
other virtio drivers are modular.

Signed-off-by: Michal Suchanek <[email protected]>
Reviewed-

char: virtio: Select VIRTIO from VIRTIO_CONSOLE.

Make it possible to have virtio console built-in when
other virtio drivers are modular.

Signed-off-by: Michal Suchanek <[email protected]>
Reviewed-by: Amit Shah <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...


Revision tags: v5.9-rc3, v5.9-rc2, v5.9-rc1, v5.8, v5.8-rc7, v5.8-rc6
# 4e74eeb2 13-Jul-2020 Alexander A. Klimov <[email protected]>

char: Replace HTTP links with HTTPS ones

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each

char: Replace HTTP links with HTTPS ones

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...


Revision tags: v5.8-rc5, v5.8-rc4, v5.8-rc3, v5.8-rc2, v5.8-rc1
# a7f7f624 13-Jun-2020 Masahiro Yamada <[email protected]>

treewide: replace '---help---' in Kconfig files with 'help'

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasi

treewide: replace '---help---' in Kconfig files with 'help'

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

a) 4 spaces + '---help---'
b) 7 spaces + '---help---'
c) 8 spaces + '---help---'
d) 1 space + 1 tab + '---help---'
e) 1 tab + '---help---' (correct indentation)
f) 1 tab + 1 space + '---help---'
g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

$ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada <[email protected]>

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Revision tags: v5.7, v5.7-rc7
# 7ade8495 21-May-2020 Michal Simek <[email protected]>

powerpc: Remove Xilinx PPC405/PPC440 support

The latest Xilinx design tools called ISE and EDK has been released in
October 2013. New tool doesn't support any PPC405/PPC440 new designs.
These platfo

powerpc: Remove Xilinx PPC405/PPC440 support

The latest Xilinx design tools called ISE and EDK has been released in
October 2013. New tool doesn't support any PPC405/PPC440 new designs.
These platforms are no longer supported and tested.

PowerPC 405/440 port is orphan from 2013 by
commit cdeb89943bfc ("MAINTAINERS: Fix incorrect status tag") and
commit 19624236cce1 ("MAINTAINERS: Update Grant's email address and maintainership")
that's why it is time to remove the support fot these platforms.

Signed-off-by: Michal Simek <[email protected]>
Signed-off-by: Christophe Leroy <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/8c593895e2cb57d232d85ce4d8c3a1aa7f0869cc.1590079968.git.christophe.leroy@csgroup.eu

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Revision tags: v5.7-rc6, v5.7-rc5, v5.7-rc4, v5.7-rc3, v5.7-rc2, v5.7-rc1, v5.6, v5.6-rc7, v5.6-rc6, v5.6-rc5, v5.6-rc4
# f52ef24b 26-Feb-2020 Arnd Bergmann <[email protected]>

rtc/alpha: remove legacy rtc driver

The old drivers/char/rtc.c driver was originally the implementation
for x86 PCs but got subsequently replaced by the rtc class driver
on all architectures except

rtc/alpha: remove legacy rtc driver

The old drivers/char/rtc.c driver was originally the implementation
for x86 PCs but got subsequently replaced by the rtc class driver
on all architectures except alpha.

Move alpha over to the portable driver and remove the old one
for good.

The CONFIG_JS_RTC option was only ever used on SPARC32 but
has not been available for many years, this was used to build
the same rtc driver with a different module name.

Cc: Richard Henderson <[email protected]>
Cc: Ivan Kokshaysky <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: [email protected]
Cc: Paul Gortmaker <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...


# 8067c0b0 26-Feb-2020 Arnd Bergmann <[email protected]>

rtc/ia64: remove legacy efirtc driver

There are two EFI RTC drivers, the original drivers/char/efirtc.c
driver and the more modern drivers/rtc/rtc-efi.c.

Both implement the same interface, but the

rtc/ia64: remove legacy efirtc driver

There are two EFI RTC drivers, the original drivers/char/efirtc.c
driver and the more modern drivers/rtc/rtc-efi.c.

Both implement the same interface, but the new one does so
in a more portable way.

Move everything over to that one and remove the old one.

Cc: [email protected]
Cc: Fenghua Yu <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Stephane Eranian <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...


# 00e37543 11-Mar-2020 Randy Dunlap <[email protected]>

tty: source all tty Kconfig files in one place

'source' (include) all of the tty/*/Kconfig files from
drivers/tty/Kconfig instead of from drivers/char/Kconfig.
This consolidates them both in source

tty: source all tty Kconfig files in one place

'source' (include) all of the tty/*/Kconfig files from
drivers/tty/Kconfig instead of from drivers/char/Kconfig.
This consolidates them both in source code and in menu
presentation to the user.

Move hvc/Kconfig and serial/Kconfig 'source' lines into the
if TTY/endif block and remove the if TTY/endif blocks from
those 2 files.

Cc: [email protected]
Cc: Jiri Slaby <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Suggested-by: Jiri Slaby <[email protected]>
Suggested-by: Arnd Bergmann <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Signed-off-by: Randy Dunlap <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...


# 8d7dc56e 11-Mar-2020 Randy Dunlap <[email protected]>

char: group dev configs togther

Group /dev/{mem,kmem,nvram,raw,port} driver configs together.
This also means that tty configs are now grouped together instead
of being split up.

This just moves Kc

char: group dev configs togther

Group /dev/{mem,kmem,nvram,raw,port} driver configs together.
This also means that tty configs are now grouped together instead
of being split up.

This just moves Kconfig lines around. There are no other changes.

Cc: [email protected]
Cc: Jiri Slaby <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Signed-off-by: Randy Dunlap <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...


Revision tags: v5.6-rc3, v5.6-rc2
# 23ae0c17 10-Feb-2020 Richard Henderson <[email protected]>

random: Make RANDOM_TRUST_CPU depend on ARCH_RANDOM

Listing the set of host architectures does not scale.
Depend instead on the existence of the architecture rng.

This will allow RANDOM_TRUST_CPU t

random: Make RANDOM_TRUST_CPU depend on ARCH_RANDOM

Listing the set of host architectures does not scale.
Depend instead on the existence of the architecture rng.

This will allow RANDOM_TRUST_CPU to be selected on arm64. Today
ARCH_RANDOM is only selected by x86, s390, and powerpc, so this does not
adversely affect other architectures.

Signed-off-by: Richard Henderson <[email protected]>
Signed-off-by: Mark Rutland <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

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Revision tags: v5.6-rc1, v5.5, v5.5-rc7, v5.5-rc6, v5.5-rc5, v5.5-rc4, v5.5-rc3, v5.5-rc2, v5.5-rc1, v5.4
# c8175bd1 20-Nov-2019 Krzysztof Kozlowski <[email protected]>

char: Fix Kconfig indentation

Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
$ sed -e 's/^ /\t/' -i */Kconfig

Signed-off-by: Krzysztof Ko

char: Fix Kconfig indentation

Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
$ sed -e 's/^ /\t/' -i */Kconfig

Signed-off-by: Krzysztof Kozlowski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...


Revision tags: v5.4-rc8, v5.4-rc7, v5.4-rc6, v5.4-rc5, v5.4-rc4, v5.4-rc3, v5.4-rc2, v5.4-rc1, v5.3, v5.3-rc8, v5.3-rc7, v5.3-rc6
# 428826f5 23-Aug-2019 Hsin-Yi Wang <[email protected]>

fdt: add support for rng-seed

Introducing a chosen node, rng-seed, which is an entropy that can be
passed to kernel called very early to increase initial device
randomness. Bootloader should provide

fdt: add support for rng-seed

Introducing a chosen node, rng-seed, which is an entropy that can be
passed to kernel called very early to increase initial device
randomness. Bootloader should provide this entropy and the value is
read from /chosen/rng-seed in DT.

Obtain of_fdt_crc32 for CRC check after early_init_dt_scan_nodes(),
since early_init_dt_scan_chosen() would modify fdt to erase rng-seed.

Add a new interface add_bootloader_randomness() for rng-seed use case.
Depends on whether the seed is trustworthy, rng seed would be passed to
add_hwgenerator_randomness(). Otherwise it would be passed to
add_device_randomness(). Decision is controlled by kernel config
RANDOM_TRUST_BOOTLOADER.

Signed-off-by: Hsin-Yi Wang <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
Reviewed-by: Theodore Ts'o <[email protected]> # drivers/char/random.c
Signed-off-by: Will Deacon <[email protected]>

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