Pull asm-generic updates from Arnd Bergmann:
"There are three sets of updates for 5.18 in the asm-generic tree:
- The set_fs()/get_fs() infrastructure gets removed for good.
This was already gone from all major architectures, but now we can
finally remove it everywhere, which loses some particularly tricky
and error-prone code. There is a small merge conflict against a
parisc cleanup, the solution is to use their new version.
- The nds32 architecture ends its tenure in the Linux kernel.
The hardware is still used and the code is in reasonable shape, but
the mainline port is not actively maintained any more, as all
remaining users are thought to run vendor kernels that would never
be updated to a future release.
- A series from Masahiro Yamada cleans up some of the uapi header
files to pass the compile-time checks"
* tag 'asm-generic-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (27 commits)
nds32: Remove the architecture
uaccess: remove CONFIG_SET_FS
ia64: remove CONFIG_SET_FS support
sh: remove CONFIG_SET_FS support
sparc64: remove CONFIG_SET_FS support
lib/test_lockup: fix kernel pointer check for separate address spaces
uaccess: generalize access_ok()
uaccess: fix type mismatch warnings from access_ok()
arm64: simplify access_ok()
m68k: fix access_ok for coldfire
MIPS: use simpler access_ok()
MIPS: Handle address errors for accesses above CPU max virtual user address
uaccess: add generic __{get,put}_kernel_nofault
nios2: drop access_ok() check from __put_user()
x86: use more conventional access_ok() definition
x86: remove __range_not_ok()
sparc64: add __{get,put}_kernel_nofault()
nds32: fix access_ok() checks in get/put_user
uaccess: fix nios2 and microblaze get_user_8()
sparc64: fix building assembly files
...
One of the things that CONFIG_HARDENED_USERCOPY sanity-checks is whether
an object that is about to be copied to/from userspace is overlapping
the stack at all. If it is, it performs a number of inexpensive
bounds checks. One of the finer-grained checks is whether an object
crosses stack frames within the stack region. Doing this on x86 with
CONFIG_FRAME_POINTER was cheap/easy. Doing it with ORC was deemed too
heavy, and was left out (a while ago), leaving the courser whole-stack
check.
The LKDTM tests USERCOPY_STACK_FRAME_TO and USERCOPY_STACK_FRAME_FROM
try to exercise these cross-frame cases to validate the defense is
working. They have been failing ever since ORC was added (which was
expected). While Muhammad was investigating various LKDTM failures[1],
he asked me for additional details on them, and I realized that when
exact stack frame boundary checking is not available (i.e. everything
except x86 with FRAME_POINTER), it could check if a stack object is at
least "current depth valid", in the sense that any object within the
stack region but not between start-of-stack and current_stack_pointer
should be considered unavailable (i.e. its lifetime is from a call no
longer present on the stack).
Introduce ARCH_HAS_CURRENT_STACK_POINTER to track which architectures
have actually implemented the common global register alias.
Additionally report usercopy bounds checking failures with an offset
from current_stack_pointer, which may assist with diagnosing failures.
The LKDTM USERCOPY_STACK_FRAME_TO and USERCOPY_STACK_FRAME_FROM tests
(once slightly adjusted in a separate patch) pass again with this fixed.
[1] https://github.com/kernelci/kernelci-project/issues/84
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Reported-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
v1: https://lore.kernel.org/lkml/20220216201449.2087956-1-keescook@chromium.org
v2: https://lore.kernel.org/lkml/20220224060342.1855457-1-keescook@chromium.org
v3: https://lore.kernel.org/lkml/20220225173345.3358109-1-keescook@chromium.org
v4: - improve commit log (akpm)
sh uses set_fs/get_fs only in one file, to handle address
errors in both user and kernel memory.
It already has an abstraction to differentiate between I/O
and memory, so adding a third class for kernel memory fits
into the same scheme and lets us kill off CONFIG_SET_FS.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Pull tracing updates from Steven Rostedt:
- simplify the Kconfig use of FTRACE and TRACE_IRQFLAGS_SUPPORT
- bootconfig can now start histograms
- bootconfig supports group/all enabling
- histograms now can put values in linear size buckets
- execnames can be passed to synthetic events
- introduce "event probes" that attach to other events and can retrieve
data from pointers of fields, or record fields as different types (a
pointer to a string as a string instead of just a hex number)
- various fixes and clean ups
* tag 'trace-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (35 commits)
tracing/doc: Fix table format in histogram code
selftests/ftrace: Add selftest for testing duplicate eprobes and kprobes
selftests/ftrace: Add selftest for testing eprobe events on synthetic events
selftests/ftrace: Add test case to test adding and removing of event probe
selftests/ftrace: Fix requirement check of README file
selftests/ftrace: Add clear_dynamic_events() to test cases
tracing: Add a probe that attaches to trace events
tracing/probes: Reject events which have the same name of existing one
tracing/probes: Have process_fetch_insn() take a void * instead of pt_regs
tracing/probe: Change traceprobe_set_print_fmt() to take a type
tracing/probes: Use struct_size() instead of defining custom macros
tracing/probes: Allow for dot delimiter as well as slash for system names
tracing/probe: Have traceprobe_parse_probe_arg() take a const arg
tracing: Have dynamic events have a ref counter
tracing: Add DYNAMIC flag for dynamic events
tracing: Replace deprecated CPU-hotplug functions.
MAINTAINERS: Add an entry for os noise/latency
tracepoint: Fix kerneldoc comments
bootconfig/tracing/ktest: Update ktest example for boot-time tracing
tools/bootconfig: Use per-group/all enable option in ftrace2bconf script
...
Pull asm-generic updates from Arnd Bergmann:
"The main content for 5.15 is a series that cleans up the handling of
strncpy_from_user() and strnlen_user(), removing a lot of slightly
incorrect versions of these in favor of the lib/strn*.c helpers that
implement these correctly and more efficiently.
The only architectures that retain a private version now are mips,
ia64, um and parisc. I had offered to convert those at all, but Thomas
Bogendoerfer wanted to keep the mips version for the moment until he
had a chance to do regression testing.
The branch also contains two patches for bitops and for ffs()"
* tag 'asm-generic-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
bitops/non-atomic: make @nr unsigned to avoid any DIV
asm-generic: ffs: Drop bogus reference to ffz location
asm-generic: reverse GENERIC_{STRNCPY_FROM,STRNLEN}_USER symbols
asm-generic: remove extra strn{cpy_from,len}_user declarations
asm-generic: uaccess: remove inline strncpy_from_user/strnlen_user
s390: use generic strncpy/strnlen from_user
microblaze: use generic strncpy/strnlen from_user
csky: use generic strncpy/strnlen from_user
arc: use generic strncpy/strnlen from_user
hexagon: use generic strncpy/strnlen from_user
h8300: remove stale strncpy_from_user
asm-generic/uaccess.h: remove __strncpy_from_user/__strnlen_user
This option is now synonymous with CONFIG_HAVE_CLK, so use
the latter globally. Any out-of-tree platform ports that
still use a private clk_get()/clk_put() implementation should
move to CONFIG_COMMON_CLK.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Pull x86 irq entry updates from Thomas Gleixner:
"The irq stack switching was moved out of the ASM entry code in course
of the entry code consolidation. It ended up being suboptimal in
various ways.
This reworks the X86 irq stack handling:
- Make the stack switching inline so the stackpointer manipulation is
not longer at an easy to find place.
- Get rid of the unnecessary indirect call.
- Avoid the double stack switching in interrupt return and reuse the
interrupt stack for softirq handling.
- A objtool fix for CONFIG_FRAME_POINTER=y builds where it got
confused about the stack pointer manipulation"
* tag 'x86-entry-2021-02-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool: Fix stack-swizzle for FRAME_POINTER=y
um: Enforce the usage of asm-generic/softirq_stack.h
x86/softirq/64: Inline do_softirq_own_stack()
softirq: Move do_softirq_own_stack() to generic asm header
softirq: Move __ARCH_HAS_DO_SOFTIRQ to Kconfig
x86: Select CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK
x86/softirq: Remove indirection in do_softirq_own_stack()
x86/entry: Use run_sysvec_on_irqstack_cond() for XEN upcall
x86/entry: Convert device interrupts to inline stack switching
x86/entry: Convert system vectors to irq stack macro
x86/irq: Provide macro for inlining irq stack switching
x86/apic: Split out spurious handling code
x86/irq/64: Adjust the per CPU irq stack pointer by 8
x86/irq: Sanitize irq stack tracking
x86/entry: Fix instrumentation annotation
Pull oprofile and dcookies removal from Viresh Kumar:
"Remove oprofile and dcookies support
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.
The dcookies stuff is only used by the oprofile code. Now that
oprofile's support is getting removed from the kernel, there is no
need for dcookies as well.
Remove kernel's old oprofile and dcookies support"
* tag 'oprofile-removal-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/linux:
fs: Remove dcookies support
drivers: Remove CONFIG_OPROFILE support
arch: xtensa: Remove CONFIG_OPROFILE support
arch: x86: Remove CONFIG_OPROFILE support
arch: sparc: Remove CONFIG_OPROFILE support
arch: sh: Remove CONFIG_OPROFILE support
arch: s390: Remove CONFIG_OPROFILE support
arch: powerpc: Remove oprofile
arch: powerpc: Stop building and using oprofile
arch: parisc: Remove CONFIG_OPROFILE support
arch: mips: Remove CONFIG_OPROFILE support
arch: microblaze: Remove CONFIG_OPROFILE support
arch: ia64: Remove rest of perfmon support
arch: ia64: Remove CONFIG_OPROFILE support
arch: hexagon: Don't select HAVE_OPROFILE
arch: arc: Remove CONFIG_OPROFILE support
arch: arm: Remove CONFIG_OPROFILE support
arch: alpha: Remove CONFIG_OPROFILE support
Merge in the recent paravirt changes to resolve conflicts caused
by objtool annotations.
Conflicts:
arch/x86/xen/xen-asm.S
Signed-off-by: Ingo Molnar <mingo@kernel.org>
To prepare for inlining do_softirq_own_stack() replace
__ARCH_HAS_DO_SOFTIRQ with a Kconfig switch and select it in the affected
architectures.
This allows in the next step to move the function prototype and the inline
stub into a seperate asm-generic header file which is required to avoid
include recursion.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210210002513.181713427@linutronix.de
Almost all machines use GENERIC_CLOCKEVENTS, so it feels wrong to
require each one to select that symbol manually.
Instead, enable it whenever CONFIG_LEGACY_TIMER_TICK is disabled as
a simplification. It should be possible to select both
GENERIC_CLOCKEVENTS and LEGACY_TIMER_TICK from an architecture now
and decide at runtime between the two.
For the clockevents arch-support.txt file, this means that additional
architectures are marked as TODO when they have at least one machine
that still uses LEGACY_TIMER_TICK, rather than being marked 'ok' when
at least one machine has been converted. This means that both m68k and
arm (for riscpc) revert to TODO.
At this point, we could just always enable CONFIG_GENERIC_CLOCKEVENTS
rather than leaving it off when not needed. I built an m68k
defconfig kernel (using gcc-10.1.0) and found that this would add
around 5.5KB in kernel image size:
text data bss dec hex filename
3861936 1092236 196656 5150828 4e986c obj-m68k/vmlinux-no-clockevent
3866201 1093832 196184 5156217 4ead79 obj-m68k/vmlinux-clockevent
On Arm (MACH_RPC), that difference appears to be twice as large,
around 11KB on top of an 6MB vmlinux.
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Pull initial set_fs() removal from Al Viro:
"Christoph's set_fs base series + fixups"
* 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: Allow a NULL pos pointer to __kernel_read
fs: Allow a NULL pos pointer to __kernel_write
powerpc: remove address space overrides using set_fs()
powerpc: use non-set_fs based maccess routines
x86: remove address space overrides using set_fs()
x86: make TASK_SIZE_MAX usable from assembly code
x86: move PAGE_OFFSET, TASK_SIZE & friends to page_{32,64}_types.h
lkdtm: remove set_fs-based tests
test_bitmap: remove user bitmap tests
uaccess: add infrastructure for kernel builds with set_fs()
fs: don't allow splice read/write without explicit ops
fs: don't allow kernel reads and writes without iter ops
sysctl: Convert to iter interfaces
proc: add a read_iter method to proc proc_ops
proc: cleanup the compat vs no compat file ops
proc: remove a level of indentation in proc_get_inode
In order to make adding configurable features into seccomp easier,
it's better to have the options at one single location, considering
especially that the bulk of seccomp code is arch-independent. An quick
look also show that many SECCOMP descriptions are outdated; they talk
about /proc rather than prctl.
As a result of moving the config option and keeping it default on,
architectures arm, arm64, csky, riscv, sh, and xtensa did not have SECCOMP
on by default prior to this and SECCOMP will be default in this change.
Architectures microblaze, mips, powerpc, s390, sh, and sparc have an
outdated depend on PROC_FS and this dependency is removed in this change.
Suggested-by: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/lkml/CAG48ez1YWz9cnp08UZgeieYRhHdqh-ch7aNwc4JRBnGyrmgfMg@mail.gmail.com/
Signed-off-by: YiFei Zhu <yifeifz2@illinois.edu>
[kees: added HAVE_ARCH_SECCOMP help text, tweaked wording]
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/9ede6ef35c847e58d61e476c6a39540520066613.1600951211.git.yifeifz2@illinois.edu
Add a CONFIG_SET_FS option that is selected by architecturess that
implement set_fs, which is all of them initially. If the option is not
set stubs for routines related to overriding the address space are
provided so that architectures can start to opt out of providing set_fs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This switches to using common code for the DMA allocations, including
potential use of the CMA allocator if configured.
Switching to the generic code enables DMA allocations from atomic
context, which is required by the DMA API documentation, and also
adds various other minor features drivers start relying upon. It
also makes sure we have on tested code base for all architectures
that require uncached pte bits for coherent DMA allocations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rich Felker <dalias@libc.org>
The code handling non-coherent DMA depends on being able to remap code
as non-cached. But that can't be done without an MMU, so using this
option on NOMMU builds is broken.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rich Felker <dalias@libc.org>
Ensure there is an order for the selects. Also remove a duplicate
one.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rich Felker <dalias@libc.org>
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 <grandmaster@al2klimov.de>
Signed-off-by: Rich Felker <dalias@libc.org>
Since the removal of core support for SH5, Cayman support can no longer
be selected.
Fixes: 37744feebc ("sh: remove sh5 support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rich Felker <dalias@libc.org>
Since commit 84af7a6194 ("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 <masahiroy@kernel.org>
Pull arch/sh updates from Rich Felker:
"Fix for arch/sh build regression with newer binutils, removal of SH5,
fixes for module exports, and misc cleanup"
* tag 'sh-for-5.8' of git://git.libc.org/linux-sh:
sh: remove sh5 support
sh: add missing EXPORT_SYMBOL() for __delay
sh: Convert ins[bwl]/outs[bwl] macros to inline functions
sh: Convert iounmap() macros to inline functions
sh: Add missing DECLARE_EXPORT() for __ashiftrt_r4_xx
sh: configs: Cleanup old Kconfig IO scheduler options
arch/sh: vmlinux.scr
sh: Replace CONFIG_MTD_M25P80 with CONFIG_MTD_SPI_NOR in sh7757lcr_defconfig
sh: sh4a: Bring back tmu3_device early device
sh5 never became a product and has probably never really worked.
Remove it by recursively deleting all associated Kconfig options
and all corresponding files.
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rich Felker <dalias@libc.org>
Most of the Kconfig commands (except defconfig and all*config) read
the .config file as a base set of CONFIG options.
When it does not exist, the files in DEFCONFIG_LIST are searched in
this order and loaded if found.
I do not see much sense in the last two lines in DEFCONFIG_LIST.
[1] ARCH_DEFCONFIG
The entry for DEFCONFIG_LIST is guarded by 'depends on !UML'. So, the
ARCH_DEFCONFIG definition in arch/x86/um/Kconfig is meaningless.
arch/{sh,sparc,x86}/Kconfig define ARCH_DEFCONFIG depending on 32 or
64 bit variant symbols. This is a little bit strange; ARCH_DEFCONFIG
should be a fixed string because the base config file is loaded before
the symbol evaluation stage.
Using KBUILD_DEFCONFIG makes more sense because it is fixed before
Kconfig is invoked. Fortunately, arch/{sh,sparc,x86}/Makefile define it
in the same way, and it works as expected. Hence, replace ARCH_DEFCONFIG
with "arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)".
[2] arch/$(ARCH)/defconfig
This file path is no longer valid. The defconfig files are always located
in the arch configs/ directories.
$ find arch -name defconfig | sort
arch/alpha/configs/defconfig
arch/arm64/configs/defconfig
arch/csky/configs/defconfig
arch/nds32/configs/defconfig
arch/riscv/configs/defconfig
arch/s390/configs/defconfig
arch/unicore32/configs/defconfig
The path arch/*/configs/defconfig is already covered by
"arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)". So, this file path is
not necessary.
I moved the default KBUILD_DEFCONFIG to the top Makefile. Otherwise,
the 7 architectures listed above would end up with endless loop of
syncconfig.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
CONFIG_ARCH_NO_COHERENT_DMA_MMAP is now functionally identical to
!CONFIG_MMU, so remove the separate symbol. The only difference is that
arm did not set it for !CONFIG_MMU, but arm uses a separate dma mapping
implementation including its own mmap method, which is handled by moving
the CONFIG_MMU check in dma_can_mmap so that is only applies to the
dma-direct case, just as the other ifdefs for it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
There are lots of documents that belong to the admin-guide but
are on random places (most under Documentation root dir).
Move them to the admin guide.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
The Kdump documentation describes procedures with admins use
in order to solve issues on their systems.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Pull m68nommu updates from Greg Ungerer:
"A series of cleanups for the FLAT format binary loader, binfmt_flat,
from Christoph.
The end goal is to support no-MMU on RISC-V, and the last patch
enables that"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
riscv: add binfmt_flat support
binfmt_flat: don't offset the data start
binfmt_flat: move the MAX_SHARED_LIBS definition to binfmt_flat.c
binfmt_flat: remove the persistent argument from flat_get_addr_from_rp
binfmt_flat: provide an asm-generic/flat.h
binfmt_flat: make support for old format binaries optional
binfmt_flat: add a ARCH_HAS_BINFMT_FLAT option
binfmt_flat: add endianess annotations
binfmt_flat: use fixed size type for the on-disk format
binfmt_flat: consolidate two version of flat_v2_reloc_t
binfmt_flat: remove the unused OLD_FLAT_FLAG_RAM definition
binfmt_flat: remove the uapi <linux/flat.h> header
binfmt_flat: replace flat_argvp_envp_on_stack with a Kconfig variable
binfmt_flat: remove flat_old_ram_flag
binfmt_flat: provide a default version of flat_get_relocate_addr
binfmt_flat: remove flat_set_persistent
binfmt_flat: remove flat_reloc_valid
Allow architectures to opt into ARCH_HAS_BINFMT_FLAT support instead of
assuming that all nommu ports support the format.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
Convert kdump documentation to ReST and add it to the
user faced manual, as the documents are mainly focused on
sysadmins that would be enabling kdump.
Note: the vmcoreinfo.rst has one very long title on one of its
sub-sections:
PG_lru|PG_private|PG_swapcache|PG_swapbacked|PG_slab|PG_hwpoision|PG_head_mask|PAGE_BUDDY_MAPCOUNT_VALUE(~PG_buddy)|PAGE_OFFLINE_MAPCOUNT_VALUE(~PG_offline)
I opted to break this one, into two entries with the same content,
in order to make it easier to display after being parsed in html and PDF.
The conversion is actually:
- add blank lines and identation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;
- mark literal blocks;
- adjust title markups.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
