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Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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This reverts commit 04e35f4495dd560db30c25efca4eecae8ec8c375.
SELinux runs with secureexec for all non-"noatsecure" domain transitions,
which means lots of processes end up hitting the stack hard-limit change
that was introduced in order to fix a race with prlimit(). That race fix
will need to be redesigned.
Reported-by: Laura Abbott <labbott@redhat.com>
Reported-by: Tomáš Trnka <trnka@scm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull Page Table Isolation (PTI) v4.14 backporting base tree from Ingo Molnar:
"This tree contains the v4.14 PTI backport preparatory tree, which
consists of four merges of upstream trees and 7 cherry-picked commits,
which the upcoming PTI work depends on"
NOTE! The resulting tree is exactly the same as the original base tree
(ie the diff between this commit and its immediate first parent is
empty).
The only reason for this merge is literally to have a common point for
the actual PTI changes so that the commits can be shared in both the
4.15 and 4.14 trees.
* 'WIP.x86-pti.base-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm/kasan: Don't use vmemmap_populate() to initialize shadow
locking/barriers: Convert users of lockless_dereference() to READ_ONCE()
locking/barriers: Add implicit smp_read_barrier_depends() to READ_ONCE()
bpf: fix build issues on um due to mising bpf_perf_event.h
perf/x86: Enable free running PEBS for REGS_USER/INTR
x86: Make X86_BUG_FXSAVE_LEAK detectable in CPUID on AMD
x86/cpufeature: Add User-Mode Instruction Prevention definitions
Pull Page Table Isolation (PTI) preparatory tree from Ingo Molnar:
"This does a rename to free up linux/pti.h to be used by the upcoming
page table isolation feature"
* 'WIP.x86-pti.base.prep-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
drivers/misc/intel/pti: Rename the header file to free up the namespace
[ Note, this is a Git cherry-pick of the following commit:
d17a1d97dc20: ("x86/mm/kasan: don't use vmemmap_populate() to initialize shadow")
... for easier x86 PTI code testing and back-porting. ]
The KASAN shadow is currently mapped using vmemmap_populate() since that
provides a semi-convenient way to map pages into init_top_pgt. However,
since that no longer zeroes the mapped pages, it is not suitable for
KASAN, which requires zeroed shadow memory.
Add kasan_populate_shadow() interface and use it instead of
vmemmap_populate(). Besides, this allows us to take advantage of
gigantic pages and use them to populate the shadow, which should save us
some memory wasted on page tables and reduce TLB pressure.
Link: http://lkml.kernel.org/r/20171103185147.2688-2-pasha.tatashin@oracle.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Bob Picco <bob.picco@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull timer fix from Thomas Gleixner:
"A single bugfix which prevents arbitrary sigev_notify values in
posix-timers"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
posix-timer: Properly check sigevent->sigev_notify
We'd like to use the 'PTI' acronym for 'Page Table Isolation' - free up the
namespace by renaming the <linux/pti.h> driver header to <linux/intel-pti.h>.
(Also standardize the header guard name while at it.)
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: J Freyensee <james_p_freyensee@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[ Note, this is a Git cherry-pick of the following commit:
506458efaf15 ("locking/barriers: Convert users of lockless_dereference() to READ_ONCE()")
... for easier x86 PTI code testing and back-porting. ]
READ_ONCE() now has an implicit smp_read_barrier_depends() call, so it
can be used instead of lockless_dereference() without any change in
semantics.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1508840570-22169-4-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull dmaengine fixes from Vinod Koul:
"This time consisting of fixes in a bunch of drivers and the dmatest
module:
- Fix for disable clk on error path in fsl-edma driver
- Disable clk fail fix in jz4740 driver
- Fix long pending bug in dmatest driver for dangling pointer
- Fix potential NULL pointer dereference in at_hdmac driver
- Error handling path in ioat driver"
* tag 'dmaengine-fix-4.15-rc4' of git://git.infradead.org/users/vkoul/slave-dma:
dmaengine: fsl-edma: disable clks on all error paths
dmaengine: jz4740: disable/unprepare clk if probe fails
dmaengine: dmatest: move callback wait queue to thread context
dmaengine: at_hdmac: fix potential NULL pointer dereference in atc_prep_dma_interleaved
dmaengine: ioat: Fix error handling path
timer_create() specifies via sigevent->sigev_notify the signal delivery for
the new timer. The valid modes are SIGEV_NONE, SIGEV_SIGNAL, SIGEV_THREAD
and (SIGEV_SIGNAL | SIGEV_THREAD_ID).
The sanity check in good_sigevent() is only checking the valid combination
for the SIGEV_THREAD_ID bit, i.e. SIGEV_SIGNAL, but if SIGEV_THREAD_ID is
not set it accepts any random value.
This has no real effects on the posix timer and signal delivery code, but
it affects show_timer() which handles the output of /proc/$PID/timers. That
function uses a string array to pretty print sigev_notify. The access to
that array has no bound checks, so random sigev_notify cause access beyond
the array bounds.
Add proper checks for the valid notify modes and remove the SIGEV_THREAD_ID
masking from various code pathes as SIGEV_NONE can never be set in
combination with SIGEV_THREAD_ID.
Reported-by: Eric Biggers <ebiggers3@gmail.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: stable@vger.kernel.org
[ Note, this is a Git cherry-pick of the following commit:
76ebbe78f739 ("locking/barriers: Add implicit smp_read_barrier_depends() to READ_ONCE()")
... for easier x86 PTI code testing and back-porting. ]
In preparation for the removal of lockless_dereference(), which is the
same as READ_ONCE() on all architectures other than Alpha, add an
implicit smp_read_barrier_depends() to READ_ONCE() so that it can be
used to head dependency chains on all architectures.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1508840570-22169-3-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With CONFIG_MTD=m and CONFIG_CRAMFS=y, we now get a link failure:
fs/cramfs/inode.o: In function `cramfs_mount': inode.c:(.text+0x220): undefined reference to `mount_mtd'
fs/cramfs/inode.o: In function `cramfs_mtd_fill_super':
inode.c:(.text+0x6d8): undefined reference to `mtd_point'
inode.c:(.text+0xae4): undefined reference to `mtd_unpoint'
This adds a more specific Kconfig dependency to avoid the broken
configuration.
Alternatively we could make CRAMFS itself depend on "MTD || !MTD" with a
similar result.
Fixes: 99c18ce580c6 ("cramfs: direct memory access support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Previously enabled clks are only disabled if clk_prepare_enable() fails.
However, there are other error paths were the previously enabled
clocks are not disabled.
To fix the problem, fsl_disable_clocks() now takes the number of clocks
that shall be disabled + unprepared. For existing calls were all clocks
were already successfully prepared + enabled, DMAMUX_NR is passed to
disable + unprepare all clocks.
In error paths were only some clocks were successfully prepared +
enabled the loop counter is passed, in order to disable + unprepare
all successfully prepared + enabled clocks.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Andreas Platschek <andreas.platschek@opentech.at>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
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