openwrt/staging/blogic.git
7 years agoinitramfs: use time64_t timestamps
Arnd Bergmann [Fri, 17 Nov 2017 23:31:04 +0000 (15:31 -0800)]
initramfs: use time64_t timestamps

The cpio format uses a 32-bit number to encode file timestamps, which
breaks initramfs support in 2038.  This reinterprets the timestamp as
unsigned, to give us another 68 years and avoids breaking until 2106.

Link: http://lkml.kernel.org/r/20171019095536.801199-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Lokesh Vutla <lokeshvutla@ti.com>
Cc: Stafford Horne <shorne@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agodrivers/watchdog: make use of devm_register_reboot_notifier()
Andrey Smirnov [Fri, 17 Nov 2017 23:31:01 +0000 (15:31 -0800)]
drivers/watchdog: make use of devm_register_reboot_notifier()

Save a bit of cleanup code by leveraging newly added
devm_register_reboot_notifier().

[akpm@linux-foundation.org: small cleanup: avoid 80-col tricks]
Link: http://lkml.kernel.org/r/20170411160615.9784-1-andrew.smirnov@gmail.com
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Cc: Chris Healy <cphealy@gmail.com>
Cc: Wim Van Sebroeck <wim@iguana.be>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agokernel/reboot.c: add devm_register_reboot_notifier()
Andrey Smirnov [Fri, 17 Nov 2017 23:30:57 +0000 (15:30 -0800)]
kernel/reboot.c: add devm_register_reboot_notifier()

Add devm_* wrapper around register_reboot_notifier to simplify device
specific reboot notifier registration/unregistration.

[akpm@linux-foundation.org: move `struct device' forward decl to top-of-file]
Link: http://lkml.kernel.org/r/20170320171753.1705-1-andrew.smirnov@gmail.com
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agokcov: update documentation
Victor Chibotaru [Fri, 17 Nov 2017 23:30:53 +0000 (15:30 -0800)]
kcov: update documentation

The updated documentation describes new KCOV mode for collecting
comparison operands.

Link: http://lkml.kernel.org/r/20171011095459.70721-3-glider@google.com
Signed-off-by: Victor Chibotaru <tchibo@google.com>
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: <syzkaller@googlegroups.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoMakefile: support flag -fsanitizer-coverage=trace-cmp
Victor Chibotaru [Fri, 17 Nov 2017 23:30:50 +0000 (15:30 -0800)]
Makefile: support flag -fsanitizer-coverage=trace-cmp

The flag enables Clang instrumentation of comparison operations
(currently not supported by GCC).  This instrumentation is needed by the
new KCOV device to collect comparison operands.

Link: http://lkml.kernel.org/r/20171011095459.70721-2-glider@google.com
Signed-off-by: Victor Chibotaru <tchibo@google.com>
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: <syzkaller@googlegroups.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agokcov: support comparison operands collection
Victor Chibotaru [Fri, 17 Nov 2017 23:30:46 +0000 (15:30 -0800)]
kcov: support comparison operands collection

Enables kcov to collect comparison operands from instrumented code.
This is done by using Clang's -fsanitize=trace-cmp instrumentation
(currently not available for GCC).

The comparison operands help a lot in fuzz testing.  E.g.  they are used
in Syzkaller to cover the interiors of conditional statements with way
less attempts and thus make previously unreachable code reachable.

To allow separate collection of coverage and comparison operands two
different work modes are implemented.  Mode selection is now done via a
KCOV_ENABLE ioctl call with corresponding argument value.

Link: http://lkml.kernel.org/r/20171011095459.70721-1-glider@google.com
Signed-off-by: Victor Chibotaru <tchibo@google.com>
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: <syzkaller@googlegroups.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agokcov: remove pointless current != NULL check
Andrey Ryabinin [Fri, 17 Nov 2017 23:30:42 +0000 (15:30 -0800)]
kcov: remove pointless current != NULL check

__sanitizer_cov_trace_pc() is a hot code, so it's worth to remove
pointless '!current' check.  Current is never NULL.

Link: http://lkml.kernel.org/r/20170929162221.32500-1-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agokernel/panic.c: add TAINT_AUX
Borislav Petkov [Fri, 17 Nov 2017 23:30:38 +0000 (15:30 -0800)]
kernel/panic.c: add TAINT_AUX

This is the gist of a patch which we've been forward-porting in our
kernels for a long time now and it probably would make a good sense to
have such TAINT_AUX flag upstream which can be used by each distro etc,
how they see fit.  This way, we won't need to forward-port a distro-only
version indefinitely.

Add an auxiliary taint flag to be used by distros and others.  This
obviates the need to forward-port whatever internal solutions people
have in favor of a single flag which they can map arbitrarily to a
definition of their pleasing.

The "X" mnemonic could also mean eXternal, which would be taint from a
distro or something else but not the upstream kernel.  We will use it to
mark modules for which we don't provide support.  I.e., a really
eXternal module.

Link: http://lkml.kernel.org/r/20170911134533.dp5mtyku5bongx4c@pd.tnic
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agopid: remove pidhash
Gargi Sharma [Fri, 17 Nov 2017 23:30:34 +0000 (15:30 -0800)]
pid: remove pidhash

pidhash is no longer required as all the information can be looked up
from idr tree.  nr_hashed represented the number of pids that had been
hashed.  Since, nr_hashed and PIDNS_HASH_ADDING are no longer relevant,
it has been renamed to pid_allocated and PIDNS_ADDING respectively.

[gs051095@gmail.com: v6]
Link: http://lkml.kernel.org/r/1507760379-21662-3-git-send-email-gs051095@gmail.com
Link: http://lkml.kernel.org/r/1507583624-22146-3-git-send-email-gs051095@gmail.com
Signed-off-by: Gargi Sharma <gs051095@gmail.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Tested-by: Tony Luck <tony.luck@intel.com> [ia64]
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agopid: replace pid bitmap implementation with IDR API
Gargi Sharma [Fri, 17 Nov 2017 23:30:30 +0000 (15:30 -0800)]
pid: replace pid bitmap implementation with IDR API

Patch series "Replacing PID bitmap implementation with IDR API", v4.

This series replaces kernel bitmap implementation of PID allocation with
IDR API.  These patches are written to simplify the kernel by replacing
custom code with calls to generic code.

The following are the stats for pid and pid_namespace object files
before and after the replacement.  There is a noteworthy change between
the IDR and bitmap implementation.

Before
   text       data        bss        dec        hex    filename
   8447       3894         64      12405       3075    kernel/pid.o
After
   text       data        bss        dec        hex    filename
   3397        304          0       3701        e75    kernel/pid.o

Before
   text       data        bss        dec        hex    filename
   5692       1842        192       7726       1e2e    kernel/pid_namespace.o
After
   text       data        bss        dec        hex    filename
   2854        216         16       3086        c0e    kernel/pid_namespace.o

The following are the stats for ps, pstree and calling readdir on /proc
for 10,000 processes.

ps:
        With IDR API    With bitmap
real    0m1.479s        0m2.319s
user    0m0.070s        0m0.060s
sys     0m0.289s        0m0.516s

pstree:
        With IDR API    With bitmap
real    0m1.024s        0m1.794s
user    0m0.348s        0m0.612s
sys     0m0.184s        0m0.264s

proc:
        With IDR API    With bitmap
real    0m0.059s        0m0.074s
user    0m0.000s        0m0.004s
sys     0m0.016s        0m0.016s

This patch (of 2):

Replace the current bitmap implementation for Process ID allocation.
Functions that are no longer required, for example, free_pidmap(),
alloc_pidmap(), etc.  are removed.  The rest of the functions are
modified to use the IDR API.  The change was made to make the PID
allocation less complex by replacing custom code with calls to generic
API.

[gs051095@gmail.com: v6]
Link: http://lkml.kernel.org/r/1507760379-21662-2-git-send-email-gs051095@gmail.com
[avagin@openvz.org: restore the old behaviour of the ns_last_pid sysctl]
Link: http://lkml.kernel.org/r/20171106183144.16368-1-avagin@openvz.org
Link: http://lkml.kernel.org/r/1507583624-22146-2-git-send-email-gs051095@gmail.com
Signed-off-by: Gargi Sharma <gs051095@gmail.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agokernel/sysctl.c: code cleanups
Ola N. Kaldestad [Fri, 17 Nov 2017 23:30:26 +0000 (15:30 -0800)]
kernel/sysctl.c: code cleanups

Remove unnecessary else block, remove redundant return and call to kfree
in if block.

Link: http://lkml.kernel.org/r/1510238435-1655-1-git-send-email-mail@okal.no
Signed-off-by: Ola N. Kaldestad <mail@okal.no>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoDocumentation/sysctl/vm.txt: fix typo
Kangmin Park [Fri, 17 Nov 2017 23:30:23 +0000 (15:30 -0800)]
Documentation/sysctl/vm.txt: fix typo

Link: http://lkml.kernel.org/r/CAKW4uUyCi=PnKf3epgFVz8z=1tMtHSOHNm+fdNxrNw3-THvRCA@mail.gmail.com
Signed-off-by: Kangmin Park <l4stpr0gr4m@gmail.com>
Cc: Jiri Kosina <trivial@kernel.org>
Cc: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agodrivers/rapidio/devices/rio_mport_cdev.c: fix error handling in 'rio_dma_transfer()'
Christophe JAILLET [Fri, 17 Nov 2017 23:38:03 +0000 (15:38 -0800)]
drivers/rapidio/devices/rio_mport_cdev.c: fix error handling in 'rio_dma_transfer()'

In case of error, 'dma_map_sg()' returns 0, not a negative value.  There
is BUG_ON() in 'dma_map_sg_attrs()' which makes sure of that.

Link: http://lkml.kernel.org/r/d4235bd2b9274e99f6c86ea71b1fa1c7bd8d0c08.1505687047.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Christian K_nig <christian.koenig@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agodrivers/rapidio/devices/rio_mport_cdev.c: fix resource leak in error handling path...
Christophe JAILLET [Fri, 17 Nov 2017 23:37:57 +0000 (15:37 -0800)]
drivers/rapidio/devices/rio_mport_cdev.c: fix resource leak in error handling path in 'rio_dma_transfer()'

If 'dma_map_sg()', we should branch to the existing error handling path
to free some resources before returning.

Link: http://lkml.kernel.org/r/61292a4f369229eee03394247385e955027283f8.1505687047.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Christian K_nig <christian.koenig@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agorapidio: constify rio_device_id
Arvind Yadav [Fri, 17 Nov 2017 23:30:15 +0000 (15:30 -0800)]
rapidio: constify rio_device_id

rio_device_id are not supposed to change at runtime.  rio driver is
working with const 'id_table'.  So mark the non-const rio_device_id
structs as const.

Link: http://lkml.kernel.org/r/1503734627-6058-2-git-send-email-arvind.yadav.cs@gmail.com
Link: http://lkml.kernel.org/r/1503734627-6058-3-git-send-email-arvind.yadav.cs@gmail.com
Link: http://lkml.kernel.org/r/1503734627-6058-4-git-send-email-arvind.yadav.cs@gmail.com
Link: http://lkml.kernel.org/r/1503734627-6058-5-git-send-email-arvind.yadav.cs@gmail.com
Link: http://lkml.kernel.org/r/1503734627-6058-6-git-send-email-arvind.yadav.cs@gmail.com
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Acked-by: Alexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agokdump: print a message in case parse_crashkernel_mem resulted in zero bytes
Dave Young [Fri, 17 Nov 2017 23:30:12 +0000 (15:30 -0800)]
kdump: print a message in case parse_crashkernel_mem resulted in zero bytes

parse_crashkernel_mem() silently returns if we get zero bytes in the
parsing function.  It is useful for debugging to add a message,
especially if the kernel cannot boot correctly.

Add a pr_info instead of pr_warn because it is expected behavior for
size = 0, eg.  crashkernel=2G-4G:128M, size will be 0 in case system
memory is less than 2G.

Link: http://lkml.kernel.org/r/20171114080129.GA6115@dhcp-128-65.nay.redhat.com
Signed-off-by: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agokernel/signal.c: remove the no longer needed SIGNAL_UNKILLABLE check in complete_signal()
Oleg Nesterov [Fri, 17 Nov 2017 23:30:08 +0000 (15:30 -0800)]
kernel/signal.c: remove the no longer needed SIGNAL_UNKILLABLE check in complete_signal()

complete_signal() checks SIGNAL_UNKILLABLE before it starts to destroy
the thread group, today this is wrong in many ways.

If nothing else, fatal_signal_pending() should always imply that the
whole thread group (except ->group_exit_task if it is not NULL) is
killed, this check breaks the rule.

After the previous changes we can rely on sig_task_ignored();
sig_fatal(sig) && SIGNAL_UNKILLABLE can only be true if we actually want
to kill this task and sig == SIGKILL OR it is traced and debugger can
intercept the signal.

This should hopefully fix the problem reported by Dmitry.  This
test-case

static int init(void *arg)
{
for (;;)
pause();
}

int main(void)
{
char stack[16 * 1024];

for (;;) {
int pid = clone(init, stack + sizeof(stack)/2,
CLONE_NEWPID | SIGCHLD, NULL);
assert(pid > 0);

assert(ptrace(PTRACE_ATTACH, pid, 0, 0) == 0);
assert(waitpid(-1, NULL, WSTOPPED) == pid);

assert(ptrace(PTRACE_DETACH, pid, 0, SIGSTOP) == 0);
assert(syscall(__NR_tkill, pid, SIGKILL) == 0);
assert(pid == wait(NULL));
}
}

triggers the WARN_ON_ONCE(!(task->jobctl & JOBCTL_STOP_PENDING)) in
task_participate_group_stop().  do_signal_stop()->signal_group_exit()
checks SIGNAL_GROUP_EXIT and return false, but task_set_jobctl_pending()
checks fatal_signal_pending() and does not set JOBCTL_STOP_PENDING.

And his should fix the minor security problem reported by Kyle,
SECCOMP_RET_TRACE can miss fatal_signal_pending() the same way if the
task is the root of a pid namespace.

Link: http://lkml.kernel.org/r/20171103184246.GD21036@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Kyle Huey <me@kylehuey.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kyle Huey <me@kylehuey.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agokernel/signal.c: protect the SIGNAL_UNKILLABLE tasks from !sig_kernel_only() signals
Oleg Nesterov [Fri, 17 Nov 2017 23:30:04 +0000 (15:30 -0800)]
kernel/signal.c: protect the SIGNAL_UNKILLABLE tasks from !sig_kernel_only() signals

Change sig_task_ignored() to drop the SIG_DFL && !sig_kernel_only()
signals even if force == T.  This simplifies the next change and this
matches the same check in get_signal() which will drop these signals
anyway.

Link: http://lkml.kernel.org/r/20171103184227.GC21036@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Kyle Huey <me@kylehuey.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agokernel/signal.c: protect the traced SIGNAL_UNKILLABLE tasks from SIGKILL
Oleg Nesterov [Fri, 17 Nov 2017 23:30:01 +0000 (15:30 -0800)]
kernel/signal.c: protect the traced SIGNAL_UNKILLABLE tasks from SIGKILL

The comment in sig_ignored() says "Tracers may want to know about even
ignored signals" but SIGKILL can not be reported to debugger and it is
just wrong to return 0 in this case: SIGKILL should only kill the
SIGNAL_UNKILLABLE task if it comes from the parent ns.

Change sig_ignored() to ignore ->ptrace if sig == SIGKILL and rely on
sig_task_ignored().

SISGTOP coming from within the namespace is not really right too but at
least debugger can intercept it, and we can't drop it here because this
will break "gdb -p 1": ptrace_attach() won't work.  Perhaps we will add
another ->ptrace check later, we will see.

Link: http://lkml.kernel.org/r/20171103184206.GB21036@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Kyle Huey <me@kylehuey.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agofat: remove redundant assignment of 0 to slots
Colin Ian King [Fri, 17 Nov 2017 23:29:57 +0000 (15:29 -0800)]
fat: remove redundant assignment of 0 to slots

The variable slots is being assigned a value of zero that is never read,
slots is being updated again a few lines later.  Remove this redundant
assignment.

Cleans clang warning: Value stored to 'slots' is never read

Link: http://lkml.kernel.org/r/20171017140258.22536-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agohfs/hfsplus: clean up unused variables in bnode.c
Christos Gkekas [Fri, 17 Nov 2017 23:29:54 +0000 (15:29 -0800)]
hfs/hfsplus: clean up unused variables in bnode.c

Delete variables 'tree' and 'sb', which are set but never used.

Link: http://lkml.kernel.org/r/1507977146-15875-1-git-send-email-chris.gekas@gmail.com
Signed-off-by: Christos Gkekas <chris.gekas@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agonilfs2: remove inode->i_version initialization
Jeff Layton [Fri, 17 Nov 2017 23:29:50 +0000 (15:29 -0800)]
nilfs2: remove inode->i_version initialization

It's never used in nilfs2.

Link: http://lkml.kernel.org/r/1510064486-1728-2-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agonilfs2: use octal for unreadable permission macro
Ryusuke Konishi [Fri, 17 Nov 2017 23:29:46 +0000 (15:29 -0800)]
nilfs2: use octal for unreadable permission macro

Replace S_IRWXUGO with 0777 because symbolic permissions are considered
harmful:

 https://lwn.net/Articles/696229/

Link: http://lkml.kernel.org/r/1509367935-3086-5-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agonilfs2: align block comments of nilfs_sufile_truncate_range() at *
Ryusuke Konishi [Fri, 17 Nov 2017 23:29:43 +0000 (15:29 -0800)]
nilfs2: align block comments of nilfs_sufile_truncate_range() at *

Fix the following checkpatch warning:

 WARNING: Block comments should align the * on each line
 #633: FILE: sufile.c:633:
 +/**
 +  * nilfs_sufile_truncate_range - truncate range of segment array

Link: http://lkml.kernel.org/r/1509367935-3086-4-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agofs, nilfs: convert nilfs_root.count from atomic_t to refcount_t
Elena Reshetova [Fri, 17 Nov 2017 23:29:39 +0000 (15:29 -0800)]
fs, nilfs: convert nilfs_root.count from atomic_t to refcount_t

atomic_t variables are currently used to implement reference counters
with the following properties:

 - counter is initialized to 1 using atomic_set()
 - a resource is freed upon counter reaching zero
 - once counter reaches zero, its further
   increments aren't allowed
 - counter schema uses basic atomic operations
   (set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided refcount_t
type and API that prevents accidental counter overflows and underflows.
This is important since overflows and underflows can lead to
use-after-free situation and be exploitable.

The variable nilfs_root.count is used as pure reference counter.
Convert it to refcount_t and fix up the operations.

Link: http://lkml.kernel.org/r/1509367935-3086-3-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agonilfs2: fix race condition that causes file system corruption
Andreas Rohner [Fri, 17 Nov 2017 23:29:35 +0000 (15:29 -0800)]
nilfs2: fix race condition that causes file system corruption

There is a race condition between nilfs_dirty_inode() and
nilfs_set_file_dirty().

When a file is opened, nilfs_dirty_inode() is called to update the
access timestamp in the inode.  It calls __nilfs_mark_inode_dirty() in a
separate transaction.  __nilfs_mark_inode_dirty() caches the ifile
buffer_head in the i_bh field of the inode info structure and marks it
as dirty.

After some data was written to the file in another transaction, the
function nilfs_set_file_dirty() is called, which adds the inode to the
ns_dirty_files list.

Then the segment construction calls nilfs_segctor_collect_dirty_files(),
which goes through the ns_dirty_files list and checks the i_bh field.
If there is a cached buffer_head in i_bh it is not marked as dirty
again.

Since nilfs_dirty_inode() and nilfs_set_file_dirty() use separate
transactions, it is possible that a segment construction that writes out
the ifile occurs in-between the two.  If this happens the inode is not
on the ns_dirty_files list, but its ifile block is still marked as dirty
and written out.

In the next segment construction, the data for the file is written out
and nilfs_bmap_propagate() updates the b-tree.  Eventually the bmap root
is written into the i_bh block, which is not dirty, because it was
written out in another segment construction.

As a result the bmap update can be lost, which leads to file system
corruption.  Either the virtual block address points to an unallocated
DAT block, or the DAT entry will be reused for something different.

The error can remain undetected for a long time.  A typical error
message would be one of the "bad btree" errors or a warning that a DAT
entry could not be found.

This bug can be reproduced reliably by a simple benchmark that creates
and overwrites millions of 4k files.

Link: http://lkml.kernel.org/r/1509367935-3086-2-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Andreas Rohner <andreas.rohner@gmx.net>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Andreas Rohner <andreas.rohner@gmx.net>
Tested-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agofs/nilfs2: convert timers to use timer_setup()
Kees Cook [Fri, 17 Nov 2017 23:29:32 +0000 (15:29 -0800)]
fs/nilfs2: convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer
to all timer callbacks, switch to using the new timer_setup() and
from_timer() to pass the timer pointer explicitly.  This requires adding
a pointer to hold the timer's target task, as the lifetime of sc_task
doesn't appear to match the timer's task.

Link: http://lkml.kernel.org/r/20171016235900.GA102729@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agosysctl: check for UINT_MAX before unsigned int min/max
Joe Lawrence [Fri, 17 Nov 2017 23:29:28 +0000 (15:29 -0800)]
sysctl: check for UINT_MAX before unsigned int min/max

Mikulas noticed in the existing do_proc_douintvec_minmax_conv() and
do_proc_dopipe_max_size_conv() introduced in this patchset, that they
inconsistently handle overflow and min/max range inputs:

For example:

  0 ... param->min - 1 ---> ERANGE
  param->min ... param->max ---> the value is accepted
  param->max + 1 ... 0x100000000L + param->min - 1 ---> ERANGE
  0x100000000L + param->min ... 0x100000000L + param->max ---> EINVAL
  0x100000000L + param->max + 1, 0x200000000L + param->min - 1 ---> ERANGE
  0x200000000L + param->min ... 0x200000000L + param->max ---> EINVAL
  0x200000000L + param->max + 1, 0x300000000L + param->min - 1 ---> ERANGE

In do_proc_do*() routines which store values into unsigned int variables
(4 bytes wide for 64-bit builds), first validate that the input unsigned
long value (8 bytes wide for 64-bit builds) will fit inside the smaller
unsigned int variable.  Then check that the unsigned int value falls
inside the specified parameter min, max range.  Otherwise the unsigned
long -> unsigned int conversion drops leading bits from the input value,
leading to the inconsistent pattern Mikulas documented above.

Link: http://lkml.kernel.org/r/1507658689-11669-5-git-send-email-joe.lawrence@redhat.com
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agopipe: add proc_dopipe_max_size() to safely assign pipe_max_size
Joe Lawrence [Fri, 17 Nov 2017 23:29:24 +0000 (15:29 -0800)]
pipe: add proc_dopipe_max_size() to safely assign pipe_max_size

pipe_max_size is assigned directly via procfs sysctl:

  static struct ctl_table fs_table[] = {
          ...
          {
                  .procname       = "pipe-max-size",
                  .data           = &pipe_max_size,
                  .maxlen         = sizeof(int),
                  .mode           = 0644,
                  .proc_handler   = &pipe_proc_fn,
                  .extra1         = &pipe_min_size,
          },
          ...

  int pipe_proc_fn(struct ctl_table *table, int write, void __user *buf,
                   size_t *lenp, loff_t *ppos)
  {
          ...
          ret = proc_dointvec_minmax(table, write, buf, lenp, ppos)
          ...

and then later rounded in-place a few statements later:

          ...
          pipe_max_size = round_pipe_size(pipe_max_size);
          ...

This leaves a window of time between initial assignment and rounding
that may be visible to other threads.  (For example, one thread sets a
non-rounded value to pipe_max_size while another reads its value.)

Similar reads of pipe_max_size are potentially racy:

  pipe.c :: alloc_pipe_info()
  pipe.c :: pipe_set_size()

Add a new proc_dopipe_max_size() that consolidates reading the new value
from the user buffer, verifying bounds, and calling round_pipe_size()
with a single assignment to pipe_max_size.

Link: http://lkml.kernel.org/r/1507658689-11669-4-git-send-email-joe.lawrence@redhat.com
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agopipe: avoid round_pipe_size() nr_pages overflow on 32-bit
Joe Lawrence [Fri, 17 Nov 2017 23:29:21 +0000 (15:29 -0800)]
pipe: avoid round_pipe_size() nr_pages overflow on 32-bit

round_pipe_size() contains a right-bit-shift expression which may
overflow, which would cause undefined results in a subsequent
roundup_pow_of_two() call.

  static inline unsigned int round_pipe_size(unsigned int size)
  {
          unsigned long nr_pages;

          nr_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
          return roundup_pow_of_two(nr_pages) << PAGE_SHIFT;
  }

PAGE_SIZE is defined as (1UL << PAGE_SHIFT), so:
  - 4 bytes wide on 32-bit (0 to 0xffffffff)
  - 8 bytes wide on 64-bit (0 to 0xffffffffffffffff)

That means that 32-bit round_pipe_size(), nr_pages may overflow to 0:

  size=0x00000000    nr_pages=0x0
  size=0x00000001    nr_pages=0x1
  size=0xfffff000    nr_pages=0xfffff
  size=0xfffff001    nr_pages=0x0         << !
  size=0xffffffff    nr_pages=0x0         << !

This is bad because roundup_pow_of_two(n) is undefined when n == 0!

64-bit is not a problem as the unsigned int size is 4 bytes wide
(similar to 32-bit) and the larger, 8 byte wide unsigned long, is
sufficient to handle the largest value of the bit shift expression:

  size=0xffffffff    nr_pages=100000

Modify round_pipe_size() to return 0 if n == 0 and updates its callers to
handle accordingly.

Link: http://lkml.kernel.org/r/1507658689-11669-3-git-send-email-joe.lawrence@redhat.com
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agopipe: match pipe_max_size data type with procfs
Joe Lawrence [Fri, 17 Nov 2017 23:29:17 +0000 (15:29 -0800)]
pipe: match pipe_max_size data type with procfs

Patch series "A few round_pipe_size() and pipe-max-size fixups", v3.

While backporting Michael's "pipe: fix limit handling" patchset to a
distro-kernel, Mikulas noticed that current upstream pipe limit handling
contains a few problems:

  1 - procfs signed wrap: echo'ing a large number into
      /proc/sys/fs/pipe-max-size and then cat'ing it back out shows a
      negative value.

  2 - round_pipe_size() nr_pages overflow on 32bit:  this would
      subsequently try roundup_pow_of_two(0), which is undefined.

  3 - visible non-rounded pipe-max-size value: there is no mutual
      exclusion or protection between the time pipe_max_size is assigned
      a raw value from proc_dointvec_minmax() and when it is rounded.

  4 - unsigned long -> unsigned int conversion makes for potential odd
      return errors from do_proc_douintvec_minmax_conv() and
      do_proc_dopipe_max_size_conv().

This version underwent the same testing as v1:
https://marc.info/?l=linux-kernel&m=150643571406022&w=2

This patch (of 4):

pipe_max_size is defined as an unsigned int:

  unsigned int pipe_max_size = 1048576;

but its procfs/sysctl representation is an integer:

  static struct ctl_table fs_table[] = {
          ...
          {
                  .procname       = "pipe-max-size",
                  .data           = &pipe_max_size,
                  .maxlen         = sizeof(int),
                  .mode           = 0644,
                  .proc_handler   = &pipe_proc_fn,
                  .extra1         = &pipe_min_size,
          },
          ...

that is signed:

  int pipe_proc_fn(struct ctl_table *table, int write, void __user *buf,
                   size_t *lenp, loff_t *ppos)
  {
          ...
          ret = proc_dointvec_minmax(table, write, buf, lenp, ppos)

This leads to signed results via procfs for large values of pipe_max_size:

  % echo 2147483647 >/proc/sys/fs/pipe-max-size
  % cat /proc/sys/fs/pipe-max-size
  -2147483648

Use unsigned operations on this variable to avoid such negative values.

Link: http://lkml.kernel.org/r/1507658689-11669-2-git-send-email-joe.lawrence@redhat.com
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoautofs: don't fail mount for transient error
NeilBrown [Fri, 17 Nov 2017 23:29:13 +0000 (15:29 -0800)]
autofs: don't fail mount for transient error

Currently if the autofs kernel module gets an error when writing to the
pipe which links to the daemon, then it marks the whole moutpoint as
catatonic, and it will stop working.

It is possible that the error is transient.  This can happen if the
daemon is slow and more than 16 requests queue up.  If a subsequent
process tries to queue a request, and is then signalled, the write to
the pipe will return -ERESTARTSYS and autofs will take that as total
failure.

So change the code to assess -ERESTARTSYS and -ENOMEM as transient
failures which only abort the current request, not the whole mountpoint.

It isn't a crash or a data corruption, but having autofs mountpoints
suddenly stop working is rather inconvenient.

Ian said:

: And given the problems with a half dozen (or so) user space applications
: consuming large amounts of CPU under heavy mount and umount activity this
: could happen more easily than we expect.

Link: http://lkml.kernel.org/r/87y3norvgp.fsf@notabene.neil.brown.name
Signed-off-by: NeilBrown <neilb@suse.com>
Acked-by: Ian Kent <raven@themaw.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoinit/version.c: include <linux/export.h> instead of <linux/module.h>
Masahiro Yamada [Fri, 17 Nov 2017 23:29:10 +0000 (15:29 -0800)]
init/version.c: include <linux/export.h> instead of <linux/module.h>

init/version.c has nothing to do with modules, so remove the
<linux/modude.h>.

Instead, include <linux/export.h> for EXPORT_SYMBOL_GPL.

This cuts off a lot of unnecessary header parsing.

Link: http://lkml.kernel.org/r/1505920984-8523-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoepoll: remove ep_call_nested() from ep_eventpoll_poll()
Jason Baron [Fri, 17 Nov 2017 23:29:06 +0000 (15:29 -0800)]
epoll: remove ep_call_nested() from ep_eventpoll_poll()

The use of ep_call_nested() in ep_eventpoll_poll(), which is the .poll
routine for an epoll fd, is used to prevent excessively deep epoll
nesting, and to prevent circular paths.

However, we are already preventing these conditions during
EPOLL_CTL_ADD.  In terms of too deep epoll chains, we do in fact allow
deep nesting of the epoll fds themselves (deeper than EP_MAX_NESTS),
however we don't allow more than EP_MAX_NESTS when an epoll file
descriptor is actually connected to a wakeup source.  Thus, we do not
require the use of ep_call_nested(), since ep_eventpoll_poll(), which is
called via ep_scan_ready_list() only continues nesting if there are
events available.

Since ep_call_nested() is implemented using a global lock, applications
that make use of nested epoll can see large performance improvements
with this change.

Davidlohr said:

: Improvements are quite obscene actually, such as for the following
: epoll_wait() benchmark with 2 level nesting on a 80 core IvyBridge:
:
: ncpus  vanilla     dirty     delta
: 1      2447092     3028315   +23.75%
: 4      231265      2986954   +1191.57%
: 8      121631      2898796   +2283.27%
: 16     59749       2902056   +4757.07%
: 32     26837      2326314   +8568.30%
: 64     12926       1341281   +10276.61%
:
: (http://linux-scalability.org/epoll/epoll-test.c)

Link: http://lkml.kernel.org/r/1509430214-5599-1-git-send-email-jbaron@akamai.com
Signed-off-by: Jason Baron <jbaron@akamai.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Salman Qazi <sqazi@google.com>
Cc: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoepoll: avoid calling ep_call_nested() from ep_poll_safewake()
Jason Baron [Fri, 17 Nov 2017 23:29:02 +0000 (15:29 -0800)]
epoll: avoid calling ep_call_nested() from ep_poll_safewake()

ep_poll_safewake() is used to wakeup potentially nested epoll file
descriptors.  The function uses ep_call_nested() to prevent entering the
same wake up queue more than once, and to prevent excessively deep
wakeup paths (deeper than EP_MAX_NESTS).  However, this is not necessary
since we are already preventing these conditions during EPOLL_CTL_ADD.
This saves extra function calls, and avoids taking a global lock during
the ep_call_nested() calls.

I have, however, left ep_call_nested() for the CONFIG_DEBUG_LOCK_ALLOC
case, since ep_call_nested() keeps track of the nesting level, and this
is required by the call to spin_lock_irqsave_nested().  It would be nice
to remove the ep_call_nested() calls for the CONFIG_DEBUG_LOCK_ALLOC
case as well, however its not clear how to simply pass the nesting level
through multiple wake_up() levels without more surgery.  In any case, I
don't think CONFIG_DEBUG_LOCK_ALLOC is generally used for production.
This patch, also apparently fixes a workload at Google that Salman Qazi
reported by completely removing the poll_safewake_ncalls->lock from
wakeup paths.

Link: http://lkml.kernel.org/r/1507920533-8812-1-git-send-email-jbaron@akamai.com
Signed-off-by: Jason Baron <jbaron@akamai.com>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Salman Qazi <sqazi@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoepoll: account epitem and eppoll_entry to kmemcg
Shakeel Butt [Fri, 17 Nov 2017 23:28:59 +0000 (15:28 -0800)]
epoll: account epitem and eppoll_entry to kmemcg

A userspace application can directly trigger the allocations from
eventpoll_epi and eventpoll_pwq slabs.  A buggy or malicious application
can consume a significant amount of system memory by triggering such
allocations.  Indeed we have seen in production where a buggy
application was leaking the epoll references and causing a burst of
eventpoll_epi and eventpoll_pwq slab allocations.  This patch opt-in the
charging of eventpoll_epi and eventpoll_pwq slabs.

There is a per-user limit (~4% of total memory if no highmem) on these
caches.  I think it is too generous particularly in the scenario where
jobs of multiple users are running on the system and the administrator
is reducing cost by overcomitting the memory.  This is unaccounted
kernel memory and will not be considered by the oom-killer.  I think by
accounting it to kmemcg, for systems with kmem accounting enabled, we
can provide better isolation between jobs of different users.

Link: http://lkml.kernel.org/r/20171003021519.23907-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agocheckpatch: do not check missing blank line before builtin_*_driver
Masahiro Yamada [Fri, 17 Nov 2017 23:28:55 +0000 (15:28 -0800)]
checkpatch: do not check missing blank line before builtin_*_driver

checkpatch.pl does not check missing blank line before module_*_driver.
I want it to behave likewise for builtin_*_driver.

Link: http://lkml.kernel.org/r/1505700081-12854-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agocheckpatch: add --strict test for lines ending in [ or (
Joe Perches [Fri, 17 Nov 2017 23:28:52 +0000 (15:28 -0800)]
checkpatch: add --strict test for lines ending in [ or (

Lines that end in an open bracket or open parenthesis are generally hard
to follow.  Lines following those ending with open parenthesis are also
rarely aligned to that open parenthesis.

Suggest not ending lines with '[' or '('

Link: http://lkml.kernel.org/r/8fd0b2b4a7482064254e37931eb9302a81d5aa2f.1508340786.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Suggested-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agocheckpatch: add TP_printk to list of logging functions
Joe Perches [Fri, 17 Nov 2017 23:28:48 +0000 (15:28 -0800)]
checkpatch: add TP_printk to list of logging functions

So the line length check can be bypassed by its callers.

Link: http://lkml.kernel.org/r/7de542c08a6e79f2ebe7c1416c9f403c23fdcc09.1508282823.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Song Liu <songliubraving@fb.com>
Tested-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agocheckpatch: allow DEFINE_PER_CPU definitions to exceed line length
Joe Perches [Fri, 17 Nov 2017 23:28:44 +0000 (15:28 -0800)]
checkpatch: allow DEFINE_PER_CPU definitions to exceed line length

Some of the definitions are very long and can't be split into multiple
lines because ctags is limited.

Exempt these lines from the line length checks.

See commit 25528213fe9f ("tags: Fix DEFINE_PER_CPU expansions") for more
details.

Link: http://lkml.kernel.org/r/1508170320.6530.15.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agocheckpatch: printks always need a KERN_<LEVEL>
Joe Perches [Fri, 17 Nov 2017 23:28:41 +0000 (15:28 -0800)]
checkpatch: printks always need a KERN_<LEVEL>

There was code in checkpatch that allowed continuation printks to be
used without KERN_CONT.  Remove the continuation check and always
require a KERN_<LEVEL>.

Link: http://lkml.kernel.org/r/61980ef41d5b9b6543da1c49055042e0ab74d308.1507047008.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoscripts/checkpatch.pl: avoid false warning missing break
Heinrich Schuchardt [Fri, 17 Nov 2017 23:28:38 +0000 (15:28 -0800)]
scripts/checkpatch.pl: avoid false warning missing break

void foo(int a)
switch (a) {
case 'h':
fun1();
exit(1);
default:
}

creates a warning "Possible switch case/default not preceded by break or
fallthrough comment".

exit( should be treated like return.

Link: http://lkml.kernel.org/r/20170910154618.25819-1-xypron.glpk@gmx.de
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agocheckpatch: support function pointers for unnamed function definition arguments
Miles Chen [Fri, 17 Nov 2017 23:28:34 +0000 (15:28 -0800)]
checkpatch: support function pointers for unnamed function definition arguments

Current unnamed function definition argument does not include function
pointer cases and it reports something like:

  WARNING: function definition argument 'void' should also have an identifier name
  +unsigned int (*dummy)(void);

Support function pointers for unnamed function arguments

Link: http://lkml.kernel.org/r/1505389925-31087-1-git-send-email-miles.chen@mediatek.com
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agolib: test module for find_*_bit() functions
Yury Norov [Fri, 17 Nov 2017 23:28:31 +0000 (15:28 -0800)]
lib: test module for find_*_bit() functions

find_bit functions are widely used in the kernel, including hot paths.
This module tests performance of those functions in 2 typical scenarios:
randomly filled bitmap with relatively equal distribution of set and
cleared bits, and sparse bitmap which has 1 set bit for 500 cleared
bits.

On ThunderX machine:

 Start testing find_bit() with random-filled bitmap
find_next_bit:          240043 cycles,  164062 iterations
find_next_zero_bit:     312848 cycles,  163619 iterations
find_last_bit:          193748 cycles,  164062 iterations
find_first_bit:      177720874 cycles,  164062 iterations

 Start testing find_bit() with sparse bitmap
find_next_bit:            3633 cycles,     656 iterations
find_next_zero_bit:     620399 cycles,  327025 iterations
find_last_bit:            3038 cycles,     656 iterations
find_first_bit:         691407 cycles,     656 iterations

[arnd@arndb.de: use correct format string for find-bit tests]
Link: http://lkml.kernel.org/r/20171113135605.3166307-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/20171109140714.13168-1-ynorov@caviumnetworks.com
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Clement Courbet <courbet@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agolib/rbtree-test: lower default params
Davidlohr Bueso [Fri, 17 Nov 2017 23:28:27 +0000 (15:28 -0800)]
lib/rbtree-test: lower default params

Fengguang reported soft lockups while running the rbtree and interval
tree test modules.  The logic for these tests all occur in init phase,
and we currently are pounding with the default values for number of
nodes and number of iterations of each test.  Reduce the latter by two
orders of magnitude.  This does not influence the value of the tests in
that one thousand times by default is enough to get the picture.

Link: http://lkml.kernel.org/r/20171109161715.xai2dtwqw2frhkcm@linux-n805
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agotools/lib/traceevent/parse-filter.c: clean up clang build warning
Cheng Jian [Fri, 17 Nov 2017 23:28:23 +0000 (15:28 -0800)]
tools/lib/traceevent/parse-filter.c: clean up clang build warning

The uniform structure filter_arg sets its union based on the difference
of enum filter_arg_type, However, some functions use implicit type
conversion obviously.

warning: implicit conversion from enumeration type 'enum filter_exp_type'
 to different enumeration type 'enum filter_op_type'

warning: implicit conversion from enumeration type 'enum filter_cmp_type'
 to different enumeration type 'enum filter_exp_type'

Link: http://lkml.kernel.org/r/1509938415-113825-1-git-send-email-cj.chengjian@huawei.com
Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Xie XiuQi <xiexiuqi@huawei.com>
Cc: Li Bin <huawei.libin@huawei.com>
Cc: Steven Rostedt (Red Hat) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agolib/nmi_backtrace.c: fix kernel text address leak
Liu, Changcheng [Fri, 17 Nov 2017 23:28:20 +0000 (15:28 -0800)]
lib/nmi_backtrace.c: fix kernel text address leak

Don't leak idle function address in NMI backtrace.

Link: http://lkml.kernel.org/r/20171106165648.GA95243@sofia
Signed-off-by: Liu Changcheng <changcheng.liu@intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agolib/genalloc.c: make the avail variable an atomic_long_t
Stephen Bates [Fri, 17 Nov 2017 23:28:16 +0000 (15:28 -0800)]
lib/genalloc.c: make the avail variable an atomic_long_t

If the amount of resources allocated to a gen_pool exceeds 2^32 then the
avail atomic overflows and this causes problems when clients try and
borrow resources from the pool.  This is only expected to be an issue on
64 bit systems.

Add the <linux/atomic.h> header to pull in atomic_long* operations.  So
that 32 bit systems continue to use atomic32_t but 64 bit systems can
use atomic64_t.

Link: http://lkml.kernel.org/r/1509033843-25667-1-git-send-email-sbates@raithlin.com
Signed-off-by: Stephen Bates <sbates@raithlin.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Daniel Mentz <danielmentz@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
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>
7 years agolib/int_sqrt: adjust comments
Peter Zijlstra [Fri, 17 Nov 2017 23:28:12 +0000 (15:28 -0800)]
lib/int_sqrt: adjust comments

Our current int_sqrt() is not rough nor any approximation; it calculates
the exact value of: floor(sqrt()).  Document this.

Link: http://lkml.kernel.org/r/20171020164645.001652117@infradead.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Anshul Garg <aksgarg1989@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Michael Davidson <md@google.com>
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>
7 years agolib/int_sqrt: optimize initial value compute
Peter Zijlstra [Fri, 17 Nov 2017 23:28:08 +0000 (15:28 -0800)]
lib/int_sqrt: optimize initial value compute

The initial value (@m) compute is:

m = 1UL << (BITS_PER_LONG - 2);
while (m > x)
m >>= 2;

Which is a linear search for the highest even bit smaller or equal to @x
We can implement this using a binary search using __fls() (or better when
its hardware implemented).

m = 1UL << (__fls(x) & ~1UL);

Especially for small values of @x; which are the more common arguments
when doing a CDF on idle times; the linear search is near to worst case,
while the binary search of __fls() is a constant 6 (or 5 on 32bit)
branches.

      cycles:                 branches:              branch-misses:

PRE:

hot:   43.633557 +- 0.034373  45.333132 +- 0.002277  0.023529 +- 0.000681
cold: 207.438411 +- 0.125840  45.333132 +- 0.002277  6.976486 +- 0.004219

SOFTWARE FLS:

hot:   29.576176 +- 0.028850  26.666730 +- 0.004511  0.019463 +- 0.000663
cold: 165.947136 +- 0.188406  26.666746 +- 0.004511  6.133897 +- 0.004386

HARDWARE FLS:

hot:   24.720922 +- 0.025161  20.666784 +- 0.004509  0.020836 +- 0.000677
cold: 132.777197 +- 0.127471  20.666776 +- 0.004509  5.080285 +- 0.003874

Averages computed over all values <128k using a LFSR to generate order.
Cold numbers have a LFSR based branch trace buffer 'confuser' ran between
each int_sqrt() invocation.

Link: http://lkml.kernel.org/r/20171020164644.936577234@infradead.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Suggested-by: Joe Perches <joe@perches.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Anshul Garg <aksgarg1989@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Michael Davidson <md@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agolib/int_sqrt: optimize small argument
Peter Zijlstra [Fri, 17 Nov 2017 23:28:04 +0000 (15:28 -0800)]
lib/int_sqrt: optimize small argument

The current int_sqrt() computation is sub-optimal for the case of small
@x.  Which is the interesting case when we're going to do cumulative
distribution functions on idle times, which we assume to be a random
variable, where the target residency of the deepest idle state gives an
upper bound on the variable (5e6ns on recent Intel chips).

In the case of small @x, the compute loop:

while (m != 0) {
b = y + m;
y >>= 1;

if (x >= b) {
x -= b;
y += m;
}
m >>= 2;
}

can be reduced to:

while (m > x)
m >>= 2;

Because y==0, b==m and until x>=m y will remain 0.

And while this is computationally equivalent, it runs much faster
because there's less code, in particular less branches.

      cycles:                 branches:              branch-misses:

OLD:

hot:   45.109444 +- 0.044117  44.333392 +- 0.002254  0.018723 +- 0.000593
cold: 187.737379 +- 0.156678  44.333407 +- 0.002254  6.272844 +- 0.004305

PRE:

hot:   67.937492 +- 0.064124  66.999535 +- 0.000488  0.066720 +- 0.001113
cold: 232.004379 +- 0.332811  66.999527 +- 0.000488  6.914634 +- 0.006568

POST:

hot:   43.633557 +- 0.034373  45.333132 +- 0.002277  0.023529 +- 0.000681
cold: 207.438411 +- 0.125840  45.333132 +- 0.002277  6.976486 +- 0.004219

Averages computed over all values <128k using a LFSR to generate order.
Cold numbers have a LFSR based branch trace buffer 'confuser' ran between
each int_sqrt() invocation.

Link: http://lkml.kernel.org/r/20171020164644.876503355@infradead.org
Fixes: 30493cc9dddb ("lib/int_sqrt.c: optimize square root algorithm")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Suggested-by: Anshul Garg <aksgarg1989@gmail.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Joe Perches <joe@perches.com>
Cc: David Miller <davem@davemloft.net>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michael Davidson <md@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agolib/test: delete five error messages for failed memory allocations
Markus Elfring [Fri, 17 Nov 2017 23:28:00 +0000 (15:28 -0800)]
lib/test: delete five error messages for failed memory allocations

Omit extra messages for a memory allocation failure in these functions.

This issue was detected by using the Coccinelle software.

Link: http://lkml.kernel.org/r/410a4c5a-4ee0-6fcc-969c-103d8e496b78@users.sourceforge.net
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agolib: add module support to string tests
Geert Uytterhoeven [Fri, 17 Nov 2017 23:27:56 +0000 (15:27 -0800)]
lib: add module support to string tests

Extract the string test code into its own source file, to allow
compiling it either to a loadable module, or built into the kernel.

Fixes: 03270c13c5ffaa6a ("lib/string.c: add testcases for memset16/32/64")
Link: http://lkml.kernel.org/r/1505397744-3387-1-git-send-email-geert@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoinclude/linux/radix-tree.h: remove unneeded #include <linux/bug.h>
Masahiro Yamada [Fri, 17 Nov 2017 23:27:53 +0000 (15:27 -0800)]
include/linux/radix-tree.h: remove unneeded #include <linux/bug.h>

This include was added by commit 187f1882b5b0 ("BUG: headers with
BUG/BUG_ON etc. need linux/bug.h") because BUG_ON() was used in this
header at that time.

Some time later, commit 6d75f366b924 ("lib: radix-tree: check accounting
of existing slot replacement users") removed the use of BUG_ON() from
this header.

Since then, there is no reason to include <linux/bug.h>.

Link: http://lkml.kernel.org/r/1505660151-4383-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Chris Mi <chrism@mellanox.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoinclude/linux/bitfield.h: include <linux/build_bug.h> instead of <linux/bug.h>
Masahiro Yamada [Fri, 17 Nov 2017 23:27:49 +0000 (15:27 -0800)]
include/linux/bitfield.h: include <linux/build_bug.h> instead of <linux/bug.h>

Since commit bc6245e5efd7 ("bug: split BUILD_BUG stuff out into
<linux/build_bug.h>"), #include <linux/build_bug.h> is better to pull
minimal headers needed for BUILG_BUG() family.

Link: http://lkml.kernel.org/r/1505700775-19826-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Dinan Gunawardena <dinan.gunawardena@netronome.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoget_maintainer: add more --self-test options
Joe Perches [Fri, 17 Nov 2017 23:27:46 +0000 (15:27 -0800)]
get_maintainer: add more --self-test options

Add tests for duplicate section headers, missing section content, link and
scm reachability.

Miscellanea:

o Add --self-test=<foo> options
  (a comma separated list of any of sections, patterns, links or scm)
  where the default without options is all tests
o Rename check_maintainers_patterns to self_test
o Rename self_test_pattern_info to self_test_info

[tom.saeger@oracle.com: improvements]
Link: http://lkml.kernel.org/r/13e3986c374902fcf08ae947e36c5c608bbe3b79.1510075301.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Tom Saeger <tom.saeger@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoget_maintainer: add --self-test for internal consistency tests
Tom Saeger [Fri, 17 Nov 2017 23:27:42 +0000 (15:27 -0800)]
get_maintainer: add --self-test for internal consistency tests

Add "--self-test" option to get_maintainer.pl to show potential
issues in MAINTAINERS file(s) content.

Pattern check warnings are shown for "F" and "X" patterns found in
MAINTAINERS file(s) which do not match any files known by git.

Link: http://lkml.kernel.org/r/64994f911b3510d0f4c8ac2e113501dfcec1f3c9.1509559540.git.tom.saeger@oracle.com
Signed-off-by: Tom Saeger <tom.saeger@oracle.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agodynamic_debug documentation: minor fixes
Randy Dunlap [Fri, 17 Nov 2017 23:27:39 +0000 (15:27 -0800)]
dynamic_debug documentation: minor fixes

Fix minor typo.

Fix missing words in explaining parsing of last line number.

Link: http://lkml.kernel.org/r/ebb7ff42-4945-103f-d5b4-f07a6f3343a7@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jason Baron <jbaron@akamai.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agodynamic-debug-howto: fix optional/omitted ending line number to be LARGE instead...
Randy Dunlap [Fri, 17 Nov 2017 23:27:35 +0000 (15:27 -0800)]
dynamic-debug-howto: fix optional/omitted ending line number to be LARGE instead of 0

line-range is supposed to treat "1-" as "1-endoffile", so
handle the special case by setting last_lineno to UINT_MAX.

Fixes this error:

  dynamic_debug:ddebug_parse_query: last-line:0 < 1st-line:1
  dynamic_debug:ddebug_exec_query: query parse failed

Link: http://lkml.kernel.org/r/10a6a101-e2be-209f-1f41-54637824788e@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agokernel/umh.c: optimize 'proc_cap_handler()'
Christophe JAILLET [Fri, 17 Nov 2017 23:27:32 +0000 (15:27 -0800)]
kernel/umh.c: optimize 'proc_cap_handler()'

If 'write' is 0, we can avoid a call to spin_lock/spin_unlock.

Link: http://lkml.kernel.org/r/20171020193331.7233-1-christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoinclude/linux/compiler-clang.h: handle randomizable anonymous structs
Sandipan Das [Fri, 17 Nov 2017 23:27:28 +0000 (15:27 -0800)]
include/linux/compiler-clang.h: handle randomizable anonymous structs

The GCC randomize layout plugin can randomize the member offsets of
sensitive kernel data structures.  To use this feature, certain
annotations and members are added to the structures which affect the
member offsets even if this plugin is not used.

All of these structures are completely randomized, except for task_struct
which leaves out some of its members.  All the other members are wrapped
within an anonymous struct with the __randomize_layout attribute.  This is
done using the randomized_struct_fields_start and
randomized_struct_fields_end defines.

When the plugin is disabled, the behaviour of this attribute can vary
based on the GCC version.  For GCC 5.1+, this attribute maps to
__designated_init otherwise it is just an empty define but the anonymous
structure is still present.  For other compilers, both
randomized_struct_fields_start and randomized_struct_fields_end default
to empty defines meaning the anonymous structure is not introduced at
all.

So, if a module compiled with Clang, such as a BPF program, needs to
access task_struct fields such as pid and comm, the offsets of these
members as recognized by Clang are different from those recognized by
modules compiled with GCC.  If GCC 4.6+ is used to build the kernel,
this can be solved by introducing appropriate defines for Clang so that
the anonymous structure is seen when determining the offsets for the
members.

Link: http://lkml.kernel.org/r/20171109064645.25581-1-sandipan@linux.vnet.ibm.com
Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agobug: fix "cut here" location for __WARN_TAINT architectures
Kees Cook [Fri, 17 Nov 2017 23:27:24 +0000 (15:27 -0800)]
bug: fix "cut here" location for __WARN_TAINT architectures

Prior to v4.11, x86 used warn_slowpath_fmt() for handling WARN()s.
After WARN() was moved to using UD0 on x86, the warning text started
appearing _before_ the "cut here" line.  This appears to have been a
long-standing bug on architectures that used __WARN_TAINT, but it didn't
get fixed.

v4.11 and earlier on x86:

  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 2956 at drivers/misc/lkdtm_bugs.c:65 lkdtm_WARNING+0x21/0x30
  This is a warning message
  Modules linked in:

v4.12 and later on x86:

  This is a warning message
  ------------[ cut here ]------------
  WARNING: CPU: 1 PID: 2982 at drivers/misc/lkdtm_bugs.c:68 lkdtm_WARNING+0x15/0x20
  Modules linked in:

With this fix:

  ------------[ cut here ]------------
  This is a warning message
  WARNING: CPU: 3 PID: 3009 at drivers/misc/lkdtm_bugs.c:67 lkdtm_WARNING+0x15/0x20

Since the __FILE__ reporting happens as part of the UD0 handler, it
isn't trivial to move the message to after the WARNING line, but at
least we can fix the position of the "cut here" line so all the various
logging tools will start including the actual runtime warning message
again, when they follow the instruction and "cut here".

Link: http://lkml.kernel.org/r/1510100869-73751-4-git-send-email-keescook@chromium.org
Fixes: 9a93848fe787 ("x86/debug: Implement __WARN() using UD0")
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agobug: define the "cut here" string in a single place
Kees Cook [Fri, 17 Nov 2017 23:27:21 +0000 (15:27 -0800)]
bug: define the "cut here" string in a single place

The "cut here" string is used in a few paths.  Define it in a single
place.

Link: http://lkml.kernel.org/r/1510100869-73751-3-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agolkdtm: include WARN format string
Kees Cook [Fri, 17 Nov 2017 23:27:17 +0000 (15:27 -0800)]
lkdtm: include WARN format string

In order to test the ordering of WARN format strings, actually include
one in LKDTM.

Link: http://lkml.kernel.org/r/1510100869-73751-2-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoiopoll: avoid -Wint-in-bool-context warning
Arnd Bergmann [Fri, 17 Nov 2017 23:27:13 +0000 (15:27 -0800)]
iopoll: avoid -Wint-in-bool-context warning

When we pass the result of a multiplication as the timeout or the delay,
we can get a warning from gcc-7:

  drivers/mmc/host/bcm2835.c:596:149: error: '*' in boolean context, suggest '&&' instead [-Werror=int-in-bool-context]
  drivers/mfd/arizona-core.c:247:195: error: '*' in boolean context, suggest '&&' instead [-Werror=int-in-bool-context]
  drivers/gpu/drm/sun4i/sun4i_hdmi_i2c.c:49:27: error: '*' in boolean context, suggest '&&' instead [-Werror=int-in-bool-context]

The warning is a bit questionable inside of a macro, but this is
intentional on the side of the gcc developers.  It is also an indication
of another problem: we evaluate the timeout and sleep arguments multiple
times, which can have undesired side-effects when those are complex
expressions.

This changes the two iopoll variants to use local variables for storing
copies of the timeouts.  This adds some more type safety, and avoids
both the double-evaluation and the gcc warning.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81484
Link: http://lkml.kernel.org/r/20170726133756.2161367-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/20171102114048.1526955-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoparse-maintainers: add ability to specify filenames
Joe Perches [Fri, 17 Nov 2017 23:27:10 +0000 (15:27 -0800)]
parse-maintainers: add ability to specify filenames

parse-maintainers.pl is convenient, but currently hard-codes the
filenames that are used.

Allow user-specified filenames to simplify the use of the script.

Link: http://lkml.kernel.org/r/48703c068b3235223ffa3b2eb268fa0a125b25e0.1502251549.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agokernel debug: support resetting WARN_ONCE for all architectures
Andi Kleen [Fri, 17 Nov 2017 23:27:06 +0000 (15:27 -0800)]
kernel debug: support resetting WARN_ONCE for all architectures

Some architectures store the WARN_ONCE state in the flags field of the
bug_entry.  Clear that one too when resetting once state through
/sys/kernel/debug/clear_warn_once

Pointed out by Michael Ellerman

Improves the earlier patch that add clear_warn_once.

[ak@linux.intel.com: add a missing ifdef CONFIG_MODULES]
Link: http://lkml.kernel.org/r/20171020170633.9593-1-andi@firstfloor.org
[akpm@linux-foundation.org: fix unused var warning]
[akpm@linux-foundation.org: Use 0200 for clear_warn_once file, per mpe]
[akpm@linux-foundation.org: clear BUGFLAG_DONE in clear_once_table(), per mpe]
Link: http://lkml.kernel.org/r/20171019204642.7404-1-andi@firstfloor.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agokernel debug: support resetting WARN*_ONCE
Andi Kleen [Fri, 17 Nov 2017 23:27:03 +0000 (15:27 -0800)]
kernel debug: support resetting WARN*_ONCE

I like _ONCE warnings because it's guaranteed that they don't flood the
log.

During testing I find it useful to reset the state of the once warnings,
so that I can rerun tests and see if they trigger again, or can
guarantee that a test run always hits the same warnings.

This patch adds a debugfs interface to reset all the _ONCE warnings so
that they appear again:

  echo 1 > /sys/kernel/debug/clear_warn_once

This is implemented by putting all the warning booleans into a special
section, and clearing it.

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20171017221455.6740-1-andi@firstfloor.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agosh/boot: add static stack-protector to pre-kernel
Kees Cook [Fri, 17 Nov 2017 23:26:59 +0000 (15:26 -0800)]
sh/boot: add static stack-protector to pre-kernel

The sh decompressor code triggers stack-protector code generation when
using CONFIG_CC_STACKPROTECTOR_STRONG.  As done for arm and mips, add a
simple static stack-protector canary.  As this wasn't protected before,
the risk of using a weak canary is minimized.  Once the kernel is
actually up, a better canary is chosen.

Link: http://lkml.kernel.org/r/1506972007-80614-2-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <mmarek@suse.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agospelling.txt: add "unnecessary" typo variants
Joe Perches [Fri, 17 Nov 2017 23:26:55 +0000 (15:26 -0800)]
spelling.txt: add "unnecessary" typo variants

Add unnecessary typos by copying the necessary typos.

Link: http://lkml.kernel.org/r/1505074722.22023.6.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoproc: use do-while in name_to_int()
Alexey Dobriyan [Fri, 17 Nov 2017 23:26:52 +0000 (15:26 -0800)]
proc: use do-while in name_to_int()

Gcc doesn't know that "len" is guaranteed to be >=1 by dcache and
generates standard while-loop prologue duplicating loop condition.

add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-27 (-27)
function                                     old     new   delta
name_to_int                                  104      77     -27

Link: http://lkml.kernel.org/r/20170912195213.GB17730@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoproc: : uninline name_to_int()
Alexey Dobriyan [Fri, 17 Nov 2017 23:26:49 +0000 (15:26 -0800)]
proc: : uninline name_to_int()

Save ~360 bytes.

add/remove: 1/0 grow/shrink: 0/4 up/down: 104/-463 (-359)
function                                     old     new   delta
name_to_int                                    -     104    +104
proc_pid_lookup                              217     126     -91
proc_lookupfd_common                         212     121     -91
proc_task_lookup                             289     194     -95
__proc_create                                588     402    -186

Link: http://lkml.kernel.org/r/20170912194850.GA17730@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoproc, coredump: add CoreDumping flag to /proc/pid/status
Roman Gushchin [Fri, 17 Nov 2017 23:26:45 +0000 (15:26 -0800)]
proc, coredump: add CoreDumping flag to /proc/pid/status

Right now there is no convenient way to check if a process is being
coredumped at the moment.

It might be necessary to recognize such state to prevent killing the
process and getting a broken coredump.  Writing a large core might take
significant time, and the process is unresponsive during it, so it might
be killed by timeout, if another process is monitoring and
killing/restarting hanging tasks.

We're getting a significant number of corrupted coredump files on
machines in our fleet, just because processes are being killed by
timeout in the middle of the core writing process.

We do have a process health check, and some agent is responsible for
restarting processes which are not responding for health check requests.
Writing a large coredump to the disk can easily exceed the reasonable
timeout (especially on an overloaded machine).

This flag will allow the agent to distinguish processes which are being
coredumped, extend the timeout for them, and let them produce a full
coredump file.

To provide an ability to detect if a process is in the state of being
coredumped, we can expose a boolean CoreDumping flag in
/proc/pid/status.

Example:
$ cat core.sh
  #!/bin/sh

  echo "|/usr/bin/sleep 10" > /proc/sys/kernel/core_pattern
  sleep 1000 &
  PID=$!

  cat /proc/$PID/status | grep CoreDumping
  kill -ABRT $PID
  sleep 1
  cat /proc/$PID/status | grep CoreDumping

$ ./core.sh
  CoreDumping: 0
  CoreDumping: 1

[guro@fb.com: document CoreDumping flag in /proc/<pid>/status]
Link: http://lkml.kernel.org/r/20170928135357.GA8470@castle.DHCP.thefacebook.com
Link: http://lkml.kernel.org/r/20170920230634.31572-1-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agomm, compaction: remove unneeded pageblock_skip_persistent() checks
Vlastimil Babka [Fri, 17 Nov 2017 23:26:41 +0000 (15:26 -0800)]
mm, compaction: remove unneeded pageblock_skip_persistent() checks

Commit f3c931633a59 ("mm, compaction: persistently skip hugetlbfs
pageblocks") has introduced pageblock_skip_persistent() checks into
migration and free scanners, to make sure pageblocks that should be
persistently skipped are marked as such, regardless of the
ignore_skip_hint flag.

Since the previous patch introduced a new no_set_skip_hint flag, the
ignore flag no longer prevents marking pageblocks as skipped.  Therefore
we can remove the special cases.  The relevant pageblocks will be marked
as skipped by the common logic which marks each pageblock where no page
could be isolated.  This makes the code simpler.

Link: http://lkml.kernel.org/r/20171102121706.21504-3-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agomm, compaction: split off flag for not updating skip hints
Vlastimil Babka [Fri, 17 Nov 2017 23:26:38 +0000 (15:26 -0800)]
mm, compaction: split off flag for not updating skip hints

Pageblock skip hints were added as a heuristic for compaction, which
shares core code with CMA.  Since CMA reliability would suffer from the
heuristics, compact_control flag ignore_skip_hint was added for the CMA
use case.  Since 6815bf3f233e ("mm/compaction: respect ignore_skip_hint
in update_pageblock_skip") the flag also means that CMA won't *update*
the skip hints in addition to ignoring them.

Today, direct compaction can also ignore the skip hints in the last
resort attempt, but there's no reason not to set them when isolation
fails in such case.  Thus, this patch splits off a new no_set_skip_hint
flag to avoid the updating, which only CMA sets.  This should improve
the heuristics a bit, and allow us to simplify the persistent skip bit
handling as the next step.

Link: http://lkml.kernel.org/r/20171102121706.21504-2-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agomm, compaction: extend pageblock_skip_persistent() to all compound pages
Vlastimil Babka [Fri, 17 Nov 2017 23:26:34 +0000 (15:26 -0800)]
mm, compaction: extend pageblock_skip_persistent() to all compound pages

pageblock_skip_persistent() checks for HugeTLB pages of pageblock order.
When clearing pageblock skip bits for compaction, the bits are not
cleared for such pageblocks, because they cannot contain base pages
suitable for migration, nor free pages to use as migration targets.

This optimization can be simply extended to all compound pages of order
equal or larger than pageblock order, because migrating such pages (if
they support it) cannot help sub-pageblock fragmentation.  This includes
THP's and also gigantic HugeTLB pages, which the current implementation
doesn't persistently skip due to a strict pageblock_order equality check
and not recognizing tail pages.

While THP pages are generally less "persistent" than HugeTLB, we can
still expect that if a THP exists at the point of
__reset_isolation_suitable(), it will exist also during the subsequent
compaction run.  The time difference here could be actually smaller than
between a compaction run that sets a (non-persistent) skip bit on a THP,
and the next compaction run that observes it.

Link: http://lkml.kernel.org/r/20171102121706.21504-1-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agomm, compaction: persistently skip hugetlbfs pageblocks
David Rientjes [Fri, 17 Nov 2017 23:26:30 +0000 (15:26 -0800)]
mm, compaction: persistently skip hugetlbfs pageblocks

It is pointless to migrate hugetlb memory as part of memory compaction
if the hugetlb size is equal to the pageblock order.  No defragmentation
is occurring in this condition.

It is also pointless to for the freeing scanner to scan a pageblock
where a hugetlb page is pinned.  Unconditionally skip these pageblocks,
and do so peristently so that they are not rescanned until it is
observed that these hugepages are no longer pinned.

It would also be possible to do this by involving the hugetlb subsystem
in marking pageblocks to no longer be skipped when they hugetlb pages
are freed.  This is a simple solution that doesn't involve any
additional subsystems in pageblock skip manipulation.

[rientjes@google.com: fix build]
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1708201734390.117182@chino.kir.corp.google.com
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1708151639130.106658@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Tested-by: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agomm, compaction: kcompactd should not ignore pageblock skip
David Rientjes [Fri, 17 Nov 2017 23:26:27 +0000 (15:26 -0800)]
mm, compaction: kcompactd should not ignore pageblock skip

Kcompactd is needlessly ignoring pageblock skip information.  It is
doing MIGRATE_SYNC_LIGHT compaction, which is no more powerful than
MIGRATE_SYNC compaction.

If compaction recently failed to isolate memory from a set of
pageblocks, there is nothing to indicate that kcompactd will be able to
do so, or that it is beneficial from attempting to isolate memory.

Use the pageblock skip hint to avoid rescanning pageblocks needlessly
until that information is reset.

Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1708151638550.106658@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agomm: shmem: remove unused info variable
Corentin Labbe [Fri, 17 Nov 2017 23:26:23 +0000 (15:26 -0800)]
mm: shmem: remove unused info variable

Fix the following warning by removing the unused variable:

  mm/shmem.c:3205:27: warning: variable 'info' set but not used [-Wunused-but-set-variable]

Link: http://lkml.kernel.org/r/1510774029-30652-1-git-send-email-clabbe@baylibre.com
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agolib/dma-debug.c: fix incorrect pfn calculation
Miles Chen [Fri, 17 Nov 2017 23:26:19 +0000 (15:26 -0800)]
lib/dma-debug.c: fix incorrect pfn calculation

dma-debug reports the following warning:

  WARNING: CPU: 3 PID: 298 at kernel-4.4/lib/dma-debug.c:604
  debug _dma_assert_idle+0x1a8/0x230()
  DMA-API: cpu touching an active dma mapped cacheline [cln=0x00000882300]
  CPU: 3 PID: 298 Comm: vold Tainted: G        W  O    4.4.22+ #1
  Hardware name: MT6739 (DT)
  Call trace:
    debug_dma_assert_idle+0x1a8/0x230
    wp_page_copy.isra.96+0x118/0x520
    do_wp_page+0x4fc/0x534
    handle_mm_fault+0xd4c/0x1310
    do_page_fault+0x1c8/0x394
    do_mem_abort+0x50/0xec

I found that debug_dma_alloc_coherent() and debug_dma_free_coherent()
assume that dma_alloc_coherent() always returns a linear address.

However it's possible that dma_alloc_coherent() returns a non-linear
address.  In this case, page_to_pfn(virt_to_page(virt)) will return an
incorrect pfn.  If the pfn is valid and mapped as a COW page, we will
hit the warning when doing wp_page_copy().

Fix this by calculating pfn for linear and non-linear addresses.

[miles.chen@mediatek.com: v4]
Link: http://lkml.kernel.org/r/1510872972-23919-1-git-send-email-miles.chen@mediatek.com
Link: http://lkml.kernel.org/r/1506484087-1177-1-git-send-email-miles.chen@mediatek.com
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agomm/z3fold.c: use kref to prevent page free/compact race
Vitaly Wool [Fri, 17 Nov 2017 23:26:16 +0000 (15:26 -0800)]
mm/z3fold.c: use kref to prevent page free/compact race

There is a race in the current z3fold implementation between
do_compact() called in a work queue context and the page release
procedure when page's kref goes to 0.

do_compact() may be waiting for page lock, which is released by
release_z3fold_page_locked right before putting the page onto the
"stale" list, and then the page may be freed as do_compact() modifies
its contents.

The mechanism currently implemented to handle that (checking the
PAGE_STALE flag) is not reliable enough.  Instead, we'll use page's kref
counter to guarantee that the page is not released if its compaction is
scheduled.  It then becomes compaction function's responsibility to
decrease the counter and quit immediately if the page was actually
freed.

Link: http://lkml.kernel.org/r/20171117092032.00ea56f42affbed19f4fcc6c@gmail.com
Signed-off-by: Vitaly Wool <vitaly.wool@sonymobile.com>
Cc: <Oleksiy.Avramchenko@sony.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agomm: fix nodemask printing
Arnd Bergmann [Fri, 17 Nov 2017 23:26:12 +0000 (15:26 -0800)]
mm: fix nodemask printing

The cleanup caused build warnings for constant mask pointers:

  mm/mempolicy.c: In function `mpol_to_str':
  ./include/linux/nodemask.h:108:11: warning: the comparison will always evaluate as `true' for the address of `nodes' will never be NULL [-Waddress]

An earlier workaround I suggested was incorporated in the version that
got merged, but that only solved the problem for gcc-7 and higher, while
gcc-4.6 through gcc-6.x still warn.

This changes the printing again to use inline functions that make it
clear to the compiler that the line that does the NULL check has no idea
whether the argument is a constant NULL.

Link: http://lkml.kernel.org/r/20171117101545.119689-1-arnd@arndb.de
Fixes: 0205f75571e3 ("mm: simplify nodemask printing")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Zhangshaokun <zhangshaokun@hisilicon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7 years agoMerge tag 'libnvdimm-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdim...
Linus Torvalds [Fri, 17 Nov 2017 17:51:57 +0000 (09:51 -0800)]
Merge tag 'libnvdimm-for-4.15' of git://git./linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm and dax updates from Dan Williams:
 "Save for a few late fixes, all of these commits have shipped in -next
  releases since before the merge window opened, and 0day has given a
  build success notification.

  The ext4 touches came from Jan, and the xfs touches have Darrick's
  reviewed-by. An xfstest for the MAP_SYNC feature has been through
  a few round of reviews and is on track to be merged.

   - Introduce MAP_SYNC and MAP_SHARED_VALIDATE, a mechanism to enable
     'userspace flush' of persistent memory updates via filesystem-dax
     mappings. It arranges for any filesystem metadata updates that may
     be required to satisfy a write fault to also be flushed ("on disk")
     before the kernel returns to userspace from the fault handler.
     Effectively every write-fault that dirties metadata completes an
     fsync() before returning from the fault handler. The new
     MAP_SHARED_VALIDATE mapping type guarantees that the MAP_SYNC flag
     is validated as supported by the filesystem's ->mmap() file
     operation.

   - Add support for the standard ACPI 6.2 label access methods that
     replace the NVDIMM_FAMILY_INTEL (vendor specific) label methods.
     This enables interoperability with environments that only implement
     the standardized methods.

   - Add support for the ACPI 6.2 NVDIMM media error injection methods.

   - Add support for the NVDIMM_FAMILY_INTEL v1.6 DIMM commands for
     latch last shutdown status, firmware update, SMART error injection,
     and SMART alarm threshold control.

   - Cleanup physical address information disclosures to be root-only.

   - Fix revalidation of the DIMM "locked label area" status to support
     dynamic unlock of the label area.

   - Expand unit test infrastructure to mock the ACPI 6.2 Translate SPA
     (system-physical-address) command and error injection commands.

  Acknowledgements that came after the commits were pushed to -next:

   - 957ac8c421ad ("dax: fix PMD faults on zero-length files"):
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
   - a39e596baa07 ("xfs: support for synchronous DAX faults") and
     7b565c9f965b ("xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()")
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>"
* tag 'libnvdimm-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (49 commits)
  acpi, nfit: add 'Enable Latch System Shutdown Status' command support
  dax: fix general protection fault in dax_alloc_inode
  dax: fix PMD faults on zero-length files
  dax: stop requiring a live device for dax_flush()
  brd: remove dax support
  dax: quiet bdev_dax_supported()
  fs, dax: unify IOMAP_F_DIRTY read vs write handling policy in the dax core
  tools/testing/nvdimm: unit test clear-error commands
  acpi, nfit: validate commands against the device type
  tools/testing/nvdimm: stricter bounds checking for error injection commands
  xfs: support for synchronous DAX faults
  xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()
  ext4: Support for synchronous DAX faults
  ext4: Simplify error handling in ext4_dax_huge_fault()
  dax: Implement dax_finish_sync_fault()
  dax, iomap: Add support for synchronous faults
  mm: Define MAP_SYNC and VM_SYNC flags
  dax: Allow tuning whether dax_insert_mapping_entry() dirties entry
  dax: Allow dax_iomap_fault() to return pfn
  dax: Fix comment describing dax_iomap_fault()
  ...

7 years agoMerge tag 'for-4.15/dm-changes-2' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Fri, 17 Nov 2017 17:40:12 +0000 (09:40 -0800)]
Merge tag 'for-4.15/dm-changes-2' of git://git./linux/kernel/git/device-mapper/linux-dm

Pull  more device mapper updates from Mike Snitzer:
 "Given your expected travel I figured I'd get these fixes to you sooner
  rather than later.

   - a DM multipath stable@ fix to silence an annoying error message
     that isn't _really_ an error

   - a DM core @stable fix for discard support that was enabled for an
     entire DM device despite only having partial support for discards
     due to a mix of discard capabilities across the underlying devices.

   - a couple other DM core discard fixes.

   - a DM bufio @stable fix that resolves a 32-bit overflow"

* tag 'for-4.15/dm-changes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm bufio: fix integer overflow when limiting maximum cache size
  dm: clear all discard attributes in queue_limits when discards are disabled
  dm: do not set 'discards_supported' in targets that do not need it
  dm: discard support requires all targets in a table support discards
  dm mpath: remove annoying message of 'blk_get_request() returned -11'

7 years agoMerge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma
Linus Torvalds [Fri, 17 Nov 2017 17:36:18 +0000 (09:36 -0800)]
Merge tag 'for-linus' of git://git./linux/kernel/git/dledford/rdma

Pull rdma maintainership update from Doug Ledford:
 "Add Jason Gunthorpe as co-maintainer of the RDMA stack.

  The change is simply to add Jason Gunthorpe to the MAINTAINERS file
  for the RDMA stack (and update him in the .mailmap). Jason and I have
  talked offline, and Jason will be filing a ticket with the k.o
  helpdesk to get an account on k.o, and then we will likely move the
  rdma tree to an area where we can both access it and use a shared repo
  + individual topic branches + merged up for-next branch as the staging
  basis for each release.

  Timing here is nice because in the US we are headed into a holiday
  period whereas Jason will be around to keep the patch flow progressing
  (I guess Canadians do their equivalent to Thanksgiving in October, so
  he doesn't have an excuse to ignore email for the next week ;-))"

[ .. and Konstantin already got Jason his kernel.org account between the
  pull request and this actual pull    - Linus ]

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma:
  RDMA: Add Jason Gunthorpe as a co-maintainer

7 years agoMerge tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Linus Torvalds [Fri, 17 Nov 2017 00:05:01 +0000 (16:05 -0800)]
Merge tag 'armsoc-drivers' of git://git./linux/kernel/git/arm/arm-soc

Pull ARM SoC driver updates from Arnd Bergmann:
 "This branch contains platform-related driver updates for ARM and
  ARM64, these are the areas that bring the changes:

  New drivers:

   - driver support for Renesas R-Car V3M (R8A77970)

   - power management support for Amlogic GX

   - a new driver for the Tegra BPMP thermal sensor

   - a new bus driver for Technologic Systems NBUS

  Changes for subsystems that prefer to merge through arm-soc:

   - the usual updates for reset controller drivers from Philipp Zabel,
     with five added drivers for SoCs in the arc, meson, socfpa,
     uniphier and mediatek families

   - updates to the ARM SCPI and PSCI frameworks, from Sudeep Holla,
     Heiner Kallweit and Lorenzo Pieralisi

  Changes specific to some ARM-based SoC

   - the Freescale/NXP DPAA QBMan drivers from PowerPC can now work on
     ARM as well

   - several changes for power management on Broadcom SoCs

   - various improvements on Qualcomm, Broadcom, Amlogic, Atmel,
     Mediatek

   - minor Cleanups for Samsung, TI OMAP SoCs"

[ NOTE! This doesn't work without the previous ARM SoC device-tree pull,
  because the R8A77970 driver is missing a header file that came from
  that pull.

  The fact that this got merged afterwards only fixes it at this point,
  and bisection of that driver will fail if/when you walk into the
  history of that driver.           - Linus ]

* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (96 commits)
  soc: amlogic: meson-gx-pwrc-vpu: fix power-off when powered by bootloader
  bus: add driver for the Technologic Systems NBUS
  memory: omap-gpmc: Remove deprecated gpmc_update_nand_reg()
  soc: qcom: remove unused label
  soc: amlogic: gx pm domain: add PM and OF dependencies
  drivers/firmware: psci_checker: Add missing destroy_timer_on_stack()
  dt-bindings: power: add amlogic meson power domain bindings
  soc: amlogic: add Meson GX VPU Domains driver
  soc: qcom: Remote filesystem memory driver
  dt-binding: soc: qcom: Add binding for rmtfs memory
  of: reserved_mem: Accessor for acquiring reserved_mem
  of/platform: Generalize /reserved-memory handling
  soc: mediatek: pwrap: fix fatal compiler error
  soc: mediatek: pwrap: fix compiler errors
  arm64: mediatek: cleanup message for platform selection
  soc: Allow test-building of MediaTek drivers
  soc: mediatek: place Kconfig for all SoC drivers under menu
  soc: mediatek: pwrap: add support for MT7622 SoC
  soc: mediatek: pwrap: add common way for setup CS timing extenstion
  soc: mediatek: pwrap: add MediaTek MT6380 as one slave of pwrap
  ..

7 years agoMerge tag 'armsoc-dt' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Linus Torvalds [Thu, 16 Nov 2017 23:48:26 +0000 (15:48 -0800)]
Merge tag 'armsoc-dt' of git://git./linux/kernel/git/arm/arm-soc

Pull ARM device-tree updates from Arnd Bergmann:
 "We add device tree files for a couple of additional SoCs in various
  areas:

  Allwinner R40/V40 for entertainment, Broadcom Hurricane 2 for
  networking, Amlogic A113D for audio, and Renesas R-Car V3M for
  automotive.

  As usual, lots of new boards get added based on those and other SoCs:

   - Actions S500 based CubieBoard6 single-board computer

   - Amlogic Meson-AXG A113D based development board
   - Amlogic S912 based Khadas VIM2 single-board computer
   - Amlogic S912 based Tronsmart Vega S96 set-top-box

   - Allwinner H5 based NanoPi NEO Plus2 single-board computer
   - Allwinner R40 based Banana Pi M2 Ultra and Berry single-board computers
   - Allwinner A83T based TBS A711 Tablet

   - Broadcom Hurricane 2 based Ubiquiti UniFi Switch 8
   - Broadcom bcm47xx based Luxul XAP-1440/XAP-810/ABR-4500/XBR-4500
     wireless access points and routers

   - NXP i.MX51 based Zodiac Inflight Innovations RDU1 board
   - NXP i.MX53 based GE Healthcare PPD biometric monitor
   - NXP i.MX6 based Pistachio single-board computer
   - NXP i.MX6 based Vining-2000 automotive diagnostic interface
   - NXP i.MX6 based Ka-Ro TX6 Computer-on-Module in additional variants

   - Qualcomm MSM8974 (Snapdragon 800) based Fairphone 2 phone
   - Qualcomm MSM8974pro (Snapdragon 801) based Sony Xperia Z2 Tablet

   - Realtek RTD1295 based set-top-boxes MeLE V9 and PROBOX2 AVA

   - Renesas R-Car V3M (R8A77970) SoC and "Eagle" reference board
   - Renesas H3ULCB and M3ULCB "Kingfisher" extension infotainment boards
   - Renasas r8a7745 based iWave G22D-SODIMM SoM

   - Rockchip rk3288 based Amarula Vyasa single-board computer

   - Samsung Exynos5800 based Odroid HC1 single-board computer

  For existing SoC support, there was a lot of ongoing work, as usual
  most of that concentrated on the Renesas, Rockchip, OMAP, i.MX,
  Amlogic and Allwinner platforms, but others were also active.

  Rob Herring and many others worked on reducing the number of issues
  that the latest version of 'dtc' now warns about. Unfortunately there
  is still a lot left to do.

  A rework of the ARM foundation model introduced several new files for
  common variations of the model"

* tag 'armsoc-dt' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (599 commits)
  arm64: dts: uniphier: route on-board device IRQ to GPIO controller for PXs3
  dt-bindings: bus: Add documentation for the Technologic Systems NBUS
  arm64: dts: actions: s900-bubblegum-96: Add fake uart5 clock
  ARM: dts: owl-s500: Add CubieBoard6
  dt-bindings: arm: actions: Add CubieBoard6
  ARM: dts: owl-s500-guitar-bb-rev-b: Add fake uart3 clock
  ARM: dts: owl-s500: Set power domains for CPU2 and CPU3
  arm: dts: mt7623: remove unused compatible string for pio node
  arm: dts: mt7623: update usb related nodes
  arm: dts: mt7623: update crypto node
  ARM: dts: sun8i: a711: Enable USB OTG
  ARM: dts: sun8i: a711: Add regulator support
  ARM: dts: sun8i: a83t: bananapi-m3: Enable AP6212 WiFi on mmc1
  ARM: dts: sun8i: a83t: cubietruck-plus: Enable AP6330 WiFi on mmc1
  ARM: dts: sun8i: a83t: Move mmc1 pinctrl setting to dtsi file
  ARM: dts: sun8i: a83t: allwinner-h8homlet-v2: Add AXP818 regulator nodes
  ARM: dts: sun8i: a83t: bananapi-m3: Add AXP813 regulator nodes
  ARM: dts: sun8i: a83t: cubietruck-plus: Add AXP818 regulator nodes
  ARM: dts: sunxi: Add dtsi for AXP81x PMIC
  arm64: dts: allwinner: H5: Restore EMAC changes
  ...

7 years agoMerge tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Linus Torvalds [Thu, 16 Nov 2017 22:05:12 +0000 (14:05 -0800)]
Merge tag 'armsoc-soc' of git://git./linux/kernel/git/arm/arm-soc

Pull ARM SoC platform updates from Arnd Bergmann:
 "Most of the commits are for defconfig changes, to enable newly added
  drivers or features that people have started using. For the changed
  lines lines, we have mostly cleanups, the affected platforms are OMAP,
  Versatile, EP93xx, Samsung, Broadcom, i.MX, and Actions.

  The largest single change is the introduction of the TI "sysc" bus
  driver, with the intention of cleaning up more legacy code.

  Two new SoC platforms get added this time:

   - Allwinner R40 is a modernized version of the A20 chip, now with a
     Quad-Core ARM Cortex-A7. According to the manufacturer, it is
     intended for "Smart Hardware"

   - Broadcom Hurricane 2 (Aka Strataconnect BCM5334X) is a family of
     chips meant for managed gigabit ethernet switches, based around a
     Cortex-A9 CPU.

  Finally, we gain SMP support for two platforms: Renesas R-Car E2 and
  Amlogic Meson8/8b, which were previously added but only supported
  uniprocessor operation"

* tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (118 commits)
  ARM: multi_v7_defconfig: Select RPMSG_VIRTIO as module
  ARM: multi_v7_defconfig: enable CONFIG_GPIO_UNIPHIER
  arm64: defconfig: enable CONFIG_GPIO_UNIPHIER
  ARM: meson: enable MESON_IRQ_GPIO in Kconfig for meson8b
  ARM: meson: Add SMP bringup code for Meson8 and Meson8b
  ARM: smp_scu: allow the platform code to read the SCU CPU status
  ARM: smp_scu: add a helper for powering on a specific CPU
  dt-bindings: Amlogic: Add Meson8 and Meson8b SMP related documentation
  ARM: OMAP3: Delete an unnecessary variable initialisation in omap3xxx_hwmod_init()
  ARM: OMAP3: Use common error handling code in omap3xxx_hwmod_init()
  ARM: defconfig: select the right SX150X driver
  arm64: defconfig: Enable QCOM_IOMMU
  arm64: Add ThunderX drivers to defconfig
  arm64: defconfig: Enable Tegra PCI controller
  cpufreq: imx6q: Move speed grading check to cpufreq driver
  arm64: defconfig: re-enable Qualcomm DB410c USB
  ARM: configs: stm32: Add MDMA support in STM32 defconfig
  ARM: imx: Enable cpuidle for i.MX6DL starting at 1.1
  bus: ti-sysc: Fix unbalanced pm_runtime_enable by adding remove
  bus: ti-sysc: mark PM functions as __maybe_unused
  ...

7 years agodm bufio: fix integer overflow when limiting maximum cache size
Eric Biggers [Thu, 16 Nov 2017 00:38:09 +0000 (16:38 -0800)]
dm bufio: fix integer overflow when limiting maximum cache size

The default max_cache_size_bytes for dm-bufio is meant to be the lesser
of 25% of the size of the vmalloc area and 2% of the size of lowmem.
However, on 32-bit systems the intermediate result in the expression

    (VMALLOC_END - VMALLOC_START) * DM_BUFIO_VMALLOC_PERCENT / 100

overflows, causing the wrong result to be computed.  For example, on a
32-bit system where the vmalloc area is 520093696 bytes, the result is
1174405 rather than the expected 130023424, which makes the maximum
cache size much too small (far less than 2% of lowmem).  This causes
severe performance problems for dm-verity users on affected systems.

Fix this by using mult_frac() to correctly multiply by a percentage.  Do
this for all places in dm-bufio that multiply by a percentage.  Also
replace (VMALLOC_END - VMALLOC_START) with VMALLOC_TOTAL, which contrary
to the comment is now defined in include/linux/vmalloc.h.

Depends-on: 9993bc635 ("sched/x86: Fix overflow in cyc2ns_offset")
Fixes: 95d402f057f2 ("dm: add bufio")
Cc: <stable@vger.kernel.org> # v3.2+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm: clear all discard attributes in queue_limits when discards are disabled
Mike Snitzer [Thu, 16 Nov 2017 20:42:26 +0000 (15:42 -0500)]
dm: clear all discard attributes in queue_limits when discards are disabled

Otherwise, it can happen that the QUEUE_FLAG_DISCARD isn't set but the
various discard attributes (which get exposed via sysfs) may be set.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm: do not set 'discards_supported' in targets that do not need it
Mike Snitzer [Thu, 16 Nov 2017 15:22:42 +0000 (10:22 -0500)]
dm: do not set 'discards_supported' in targets that do not need it

The DM target's 'discards_supported' flag is intended to act as an
override.  Meaning, even if the underlying storage doesn't support
discards the DM target will.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm: discard support requires all targets in a table support discards
Mike Snitzer [Tue, 14 Nov 2017 20:40:52 +0000 (15:40 -0500)]
dm: discard support requires all targets in a table support discards

A DM device with a mix of discard capabilities (due to some underlying
devices not having discard support) _should_ just return -EOPNOTSUPP for
the region of the device that doesn't support discards (even if only by
way of the underlying driver formally not supporting discards).  BUT,
that does ask the underlying driver to handle something that it never
advertised support for.  In doing so we're exposing users to the
potential for a underlying disk driver hanging if/when a discard is
issued a the device that is incapable and never claimed to support
discards.

Fix this by requiring that each DM target in a DM table provide discard
support as a prereq for a DM device to advertise support for discards.

This may cause some configurations that were happily supporting discards
(even in the face of a mix of discard support) to stop supporting
discards -- but the risk of users hitting driver hangs, and forced
reboots, outweighs supporting those fringe mixed discard
configurations.

Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agodm mpath: remove annoying message of 'blk_get_request() returned -11'
Ming Lei [Sat, 30 Sep 2017 11:46:48 +0000 (19:46 +0800)]
dm mpath: remove annoying message of 'blk_get_request() returned -11'

It is very normal to see allocation failure, especially with blk-mq
request_queues, so it's unnecessary to report this error and annoy
people.

In practice this 'blk_get_request() returned -11' error gets logged
quite frequently when a blk-mq DM multipath device sees heavy IO.

This change is marked for stable@ because the annoying message in
question was included in stable@ commit 7083abbbf.

Fixes: 7083abbbf ("dm mpath: avoid that path removal can trigger an infinite loop")
Cc: stable@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
7 years agoMerge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Linus Torvalds [Thu, 16 Nov 2017 21:14:46 +0000 (13:14 -0800)]
Merge tag 'for_linus' of git://git./linux/kernel/git/mst/vhost

Pull virtio updates from Michael Tsirkin:
 "Fixes in qemu, vhost and virtio"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  fw_cfg: fix the command line module name
  vhost/vsock: fix uninitialized vhost_vsock->guest_cid
  vhost: fix end of range for access_ok
  vhost/scsi: Use safe iteration in vhost_scsi_complete_cmd_work()
  virtio_balloon: fix deadlock on OOM

7 years agoMerge tag 'for-linus-4.15-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Thu, 16 Nov 2017 21:06:27 +0000 (13:06 -0800)]
Merge tag 'for-linus-4.15-rc1-tag' of git://git./linux/kernel/git/xen/tip

Pull xen updates from Juergen Gross:
 "Xen features and fixes for v4.15-rc1

  Apart from several small fixes it contains the following features:

   - a series by Joao Martins to add vdso support of the pv clock
     interface

   - a series by Juergen Gross to add support for Xen pv guests to be
     able to run on 5 level paging hosts

   - a series by Stefano Stabellini adding the Xen pvcalls frontend
     driver using a paravirtualized socket interface"

* tag 'for-linus-4.15-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (34 commits)
  xen/pvcalls: fix potential endless loop in pvcalls-front.c
  xen/pvcalls: Add MODULE_LICENSE()
  MAINTAINERS: xen, kvm: track pvclock-abi.h changes
  x86/xen/time: setup vcpu 0 time info page
  x86/xen/time: set pvclock flags on xen_time_init()
  x86/pvclock: add setter for pvclock_pvti_cpu0_va
  ptp_kvm: probe for kvm guest availability
  xen/privcmd: remove unused variable pageidx
  xen: select grant interface version
  xen: update arch/x86/include/asm/xen/cpuid.h
  xen: add grant interface version dependent constants to gnttab_ops
  xen: limit grant v2 interface to the v1 functionality
  xen: re-introduce support for grant v2 interface
  xen: support priv-mapping in an HVM tools domain
  xen/pvcalls: remove redundant check for irq >= 0
  xen/pvcalls: fix unsigned less than zero error check
  xen/time: Return -ENODEV from xen_get_wallclock()
  xen/pvcalls-front: mark expected switch fall-through
  xen: xenbus_probe_frontend: mark expected switch fall-throughs
  xen/time: do not decrease steal time after live migration on xen
  ...

7 years agoMerge tag 'kvm-4.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Linus Torvalds [Thu, 16 Nov 2017 21:00:24 +0000 (13:00 -0800)]
Merge tag 'kvm-4.15-1' of git://git./virt/kvm/kvm

Pull KVM updates from Radim Krčmář:
 "First batch of KVM changes for 4.15

  Common:
   - Python 3 support in kvm_stat
   - Accounting of slabs to kmemcg

  ARM:
   - Optimized arch timer handling for KVM/ARM
   - Improvements to the VGIC ITS code and introduction of an ITS reset
     ioctl
   - Unification of the 32-bit fault injection logic
   - More exact external abort matching logic

  PPC:
   - Support for running hashed page table (HPT) MMU mode on a host that
     is using the radix MMU mode; single threaded mode on POWER 9 is
     added as a pre-requisite
   - Resolution of merge conflicts with the last second 4.14 HPT fixes
   - Fixes and cleanups

  s390:
   - Some initial preparation patches for exitless interrupts and crypto
   - New capability for AIS migration
   - Fixes

  x86:
   - Improved emulation of LAPIC timer mode changes, MCi_STATUS MSRs,
     and after-reset state
   - Refined dependencies for VMX features
   - Fixes for nested SMI injection
   - A lot of cleanups"

* tag 'kvm-4.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (89 commits)
  KVM: s390: provide a capability for AIS state migration
  KVM: s390: clear_io_irq() requests are not expected for adapter interrupts
  KVM: s390: abstract conversion between isc and enum irq_types
  KVM: s390: vsie: use common code functions for pinning
  KVM: s390: SIE considerations for AP Queue virtualization
  KVM: s390: document memory ordering for kvm_s390_vcpu_wakeup
  KVM: PPC: Book3S HV: Cosmetic post-merge cleanups
  KVM: arm/arm64: fix the incompatible matching for external abort
  KVM: arm/arm64: Unify 32bit fault injection
  KVM: arm/arm64: vgic-its: Implement KVM_DEV_ARM_ITS_CTRL_RESET
  KVM: arm/arm64: Document KVM_DEV_ARM_ITS_CTRL_RESET
  KVM: arm/arm64: vgic-its: Free caches when GITS_BASER Valid bit is cleared
  KVM: arm/arm64: vgic-its: New helper functions to free the caches
  KVM: arm/arm64: vgic-its: Remove kvm_its_unmap_device
  arm/arm64: KVM: Load the timer state when enabling the timer
  KVM: arm/arm64: Rework kvm_timer_should_fire
  KVM: arm/arm64: Get rid of kvm_timer_flush_hwstate
  KVM: arm/arm64: Avoid phys timer emulation in vcpu entry/exit
  KVM: arm/arm64: Move phys_timer_emulate function
  KVM: arm/arm64: Use kvm_arm_timer_set/get_reg for guest register traps
  ...

7 years agoRDMA: Add Jason Gunthorpe as a co-maintainer
Jason Gunthorpe [Thu, 16 Nov 2017 20:44:00 +0000 (13:44 -0700)]
RDMA: Add Jason Gunthorpe as a co-maintainer

As was discussed in September and October, add Jason along with
Doug to have a team maintainership model for the RDMA subystem.

Mellanox Technologies will be funding Jason's independent work on
the maintainership.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
7 years agoMerge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm
Linus Torvalds [Thu, 16 Nov 2017 20:50:35 +0000 (12:50 -0800)]
Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

Pull ARM updates from Russell King:

 - add support for ELF fdpic binaries on both MMU and noMMU platforms

 - linker script cleanups

 - support for compressed .data section for XIP images

 - discard memblock arrays when possible

 - various cleanups

 - atomic DMA pool updates

 - better diagnostics of missing/corrupt device tree

 - export information to allow userspace kexec tool to place images more
   inteligently, so that the device tree isn't overwritten by the
   booting kernel

 - make early_printk more efficient on semihosted systems

 - noMMU cleanups

 - SA1111 PCMCIA update in preparation for further cleanups

* 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (38 commits)
  ARM: 8719/1: NOMMU: work around maybe-uninitialized warning
  ARM: 8717/2: debug printch/printascii: translate '\n' to "\r\n" not "\n\r"
  ARM: 8713/1: NOMMU: Support MPU in XIP configuration
  ARM: 8712/1: NOMMU: Use more MPU regions to cover memory
  ARM: 8711/1: V7M: Add support for MPU to M-class
  ARM: 8710/1: Kconfig: Kill CONFIG_VECTORS_BASE
  ARM: 8709/1: NOMMU: Disallow MPU for XIP
  ARM: 8708/1: NOMMU: Rework MPU to be mostly done in C
  ARM: 8707/1: NOMMU: Update MPU accessors to use cp15 helpers
  ARM: 8706/1: NOMMU: Move out MPU setup in separate module
  ARM: 8702/1: head-common.S: Clear lr before jumping to start_kernel()
  ARM: 8705/1: early_printk: use printascii() rather than printch()
  ARM: 8703/1: debug.S: move hexbuf to a writable section
  ARM: add additional table to compressed kernel
  ARM: decompressor: fix BSS size calculation
  pcmcia: sa1111: remove special sa1111 mmio accessors
  pcmcia: sa1111: use sa1111_get_irq() to obtain IRQ resources
  ARM: better diagnostics with missing/corrupt dtb
  ARM: 8699/1: dma-mapping: Remove init_dma_coherent_pool_size()
  ARM: 8698/1: dma-mapping: Mark atomic_pool as __ro_after_init
  ..

7 years agoMerge tag 'powerpc-4.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc...
Linus Torvalds [Thu, 16 Nov 2017 20:47:46 +0000 (12:47 -0800)]
Merge tag 'powerpc-4.15-1' of git://git./linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "A bit of a small release, I suspect in part due to me travelling for
  KS. But my backlog of patches to review is smaller than usual, so I
  think in part folks just didn't send as much this cycle.

  Non-highlights:

   - Five fixes for the >128T address space handling, both to fix bugs
     in our implementation and to bring the semantics exactly into line
     with x86.

  Highlights:

   - Support for a new OPAL call on bare metal machines which gives us a
     true NMI (ie. is not masked by MSR[EE]=0) for debugging etc.

   - Support for Power9 DD2 in the CXL driver.

   - Improvements to machine check handling so that uncorrectable errors
     can be reported into the generic memory_failure() machinery.

   - Some fixes and improvements for VPHN, which is used under PowerVM
     to notify the Linux partition of topology changes.

   - Plumbing to enable TM (transactional memory) without suspend on
     some Power9 processors (PPC_FEATURE2_HTM_NO_SUSPEND).

   - Support for emulating vector loads form cache-inhibited memory, on
     some Power9 revisions.

   - Disable the fast-endian switch "syscall" by default (behind a
     CONFIG), we believe it has never had any users.

   - A major rework of the API drivers use when initiating and waiting
     for long running operations performed by OPAL firmware, and changes
     to the powernv_flash driver to use the new API.

   - Several fixes for the handling of FP/VMX/VSX while processes are
     using transactional memory.

   - Optimisations of TLB range flushes when using the radix MMU on
     Power9.

   - Improvements to the VAS facility used to access coprocessors on
     Power9, and related improvements to the way the NX crypto driver
     handles requests.

   - Implementation of PMEM_API and UACCESS_FLUSHCACHE for 64-bit.

  Thanks to: Alexey Kardashevskiy, Alistair Popple, Allen Pais, Andrew
  Donnellan, Aneesh Kumar K.V, Arnd Bergmann, Balbir Singh, Benjamin
  Herrenschmidt, Breno Leitao, Christophe Leroy, Christophe Lombard,
  Cyril Bur, Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven,
  Guilherme G. Piccoli, Gustavo Romero, Haren Myneni, Joel Stanley,
  Kamalesh Babulal, Kautuk Consul, Markus Elfring, Masami Hiramatsu,
  Michael Bringmann, Michael Neuling, Michal Suchanek, Naveen N. Rao,
  Nicholas Piggin, Oliver O'Halloran, Paul Mackerras, Pedro Miraglia
  Franco de Carvalho, Philippe Bergheaud, Sandipan Das, Seth Forshee,
  Shriya, Stephen Rothwell, Stewart Smith, Sukadev Bhattiprolu, Tyrel
  Datwyler, Vaibhav Jain, Vaidyanathan Srinivasan, and William A.
  Kennington III"

* tag 'powerpc-4.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (151 commits)
  powerpc/64s: Fix Power9 DD2.0 workarounds by adding DD2.1 feature
  powerpc/64s: Fix masking of SRR1 bits on instruction fault
  powerpc/64s: mm_context.addr_limit is only used on hash
  powerpc/64s/radix: Fix 128TB-512TB virtual address boundary case allocation
  powerpc/64s/hash: Allow MAP_FIXED allocations to cross 128TB boundary
  powerpc/64s/hash: Fix fork() with 512TB process address space
  powerpc/64s/hash: Fix 128TB-512TB virtual address boundary case allocation
  powerpc/64s/hash: Fix 512T hint detection to use >= 128T
  powerpc: Fix DABR match on hash based systems
  powerpc/signal: Properly handle return value from uprobe_deny_signal()
  powerpc/fadump: use kstrtoint to handle sysfs store
  powerpc/lib: Implement UACCESS_FLUSHCACHE API
  powerpc/lib: Implement PMEM API
  powerpc/powernv/npu: Don't explicitly flush nmmu tlb
  powerpc/powernv/npu: Use flush_all_mm() instead of flush_tlb_mm()
  powerpc/powernv/idle: Round up latency and residency values
  powerpc/kprobes: refactor kprobe_lookup_name for safer string operations
  powerpc/kprobes: Blacklist emulate_update_regs() from kprobes
  powerpc/kprobes: Do not disable interrupts for optprobes and kprobes_on_ftrace
  powerpc/kprobes: Disable preemption before invoking probe handler for optprobes
  ...

7 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm...
Linus Torvalds [Thu, 16 Nov 2017 20:20:15 +0000 (12:20 -0800)]
Merge branch 'for-linus' of git://git./linux/kernel/git/ebiederm/user-namespace

Pull user namespace update from Eric Biederman:
 "The only change that is production ready this round is the work to
  increase the number of uid and gid mappings a user namespace can
  support from 5 to 340.

  This code was carefully benchmarked and it was confirmed that in the
  existing cases the performance remains the same. In the worst case
  with 340 mappings an cache cold stat times go from 158ns to 248ns.
  That is noticable but still quite small, and only the people who are
  doing crazy things pay the cost.

  This work uncovered some documentation and cleanup opportunities in
  the mapping code, and patches to make those cleanups and improve the
  documentation will be coming in the next merge window"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  userns: Simplify insert_extent
  userns: Make map_id_down a wrapper for map_id_range_down
  userns: Don't read extents twice in m_start
  userns: Simplify the user and group mapping functions
  userns: Don't special case a count of 0
  userns: bump idmap limits to 340
  userns: use union in {g,u}idmap struct