Commit graph

485 commits

Author SHA1 Message Date
Linus Torvalds
8f3207c7ea TTY/Serial patches for 4.12-rc1
Here is the "big" TTY/Serial patch updates for 4.12-rc1
 
 Not a lot of new things here, the normal number of serial driver updates
 and additions, tiny bugs fixed, and some core files split up to make
 future changes a bit easier for Nicolas's "tiny-tty" work.
 
 All of these have been in linux-next for a while.  There will be a merge
 conflict with include/linux/serdev.h coming from the bluetooth tree
 merge, which we knew about, as we wanted some of the serdev changes to
 go in through that tree.  I'll send the expected merge result as a
 follow-on message.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial updates from Greg KH:
 "Here is the "big" TTY/Serial patch updates for 4.12-rc1

  Not a lot of new things here, the normal number of serial driver
  updates and additions, tiny bugs fixed, and some core files split up
  to make future changes a bit easier for Nicolas's "tiny-tty" work.

  All of these have been in linux-next for a while"

* tag 'tty-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (62 commits)
  serial: small Makefile reordering
  tty: split job control support into a file of its own
  tty: move baudrate handling code to a file of its own
  console: move console_init() out of tty_io.c
  serial: 8250_early: Add earlycon support for Palmchip UART
  tty: pl011: use "qdf2400_e44" as the earlycon name for QDF2400 E44
  vt: make mouse selection of non-ASCII consistent
  vt: set mouse selection word-chars to gpm's default
  imx-serial: Reduce RX DMA startup latency when opening for reading
  serial: omap: suspend device on probe errors
  serial: omap: fix runtime-pm handling on unbind
  tty: serial: omap: add UPF_BOOT_AUTOCONF flag for DT init
  serial: samsung: Remove useless spinlock
  serial: samsung: Add missing checks for dma_map_single failure
  serial: samsung: Use right device for DMA-mapping calls
  serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off
  tty: fix comment typo s/repsonsible/responsible/
  tty: amba-pl011: Fix spurious TX interrupts
  serial: xuartps: Enable clocks in the pm disable case also
  serial: core: Re-use struct uart_port {name} field
  ...
2017-05-08 18:49:23 -07:00
Linus Torvalds
4c174688ee New features for this release:
o Pretty much a full rewrite of the processing of function plugins.
    i.e. echo do_IRQ:stacktrace > set_ftrace_filter
 
  o The rewrite was needed to add plugins to be unique to tracing instances.
    i.e. mkdir instance/foo; cd instances/foo; echo do_IRQ:stacktrace > set_ftrace_filter
    The old way was written very hacky. This removes a lot of those hacks.
 
  o New "function-fork" tracing option. When set, pids in the set_ftrace_pid
    will have their children added when the processes with their pids
    listed in the set_ftrace_pid file forks.
 
  o Exposure of "maxactive" for kretprobe in kprobe_events
 
  o Allow for builtin init functions to be traced by the function tracer
    (via the kernel command line). Module init function tracing will come
    in the next release.
 
  o Added more selftests, and have selftests also test in an instance.
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Merge tag 'trace-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "New features for this release:

   - Pretty much a full rewrite of the processing of function plugins.
     i.e. echo do_IRQ:stacktrace > set_ftrace_filter

   - The rewrite was needed to add plugins to be unique to tracing
     instances. i.e. mkdir instance/foo; cd instances/foo; echo
     do_IRQ:stacktrace > set_ftrace_filter The old way was written very
     hacky. This removes a lot of those hacks.

   - New "function-fork" tracing option. When set, pids in the
     set_ftrace_pid will have their children added when the processes
     with their pids listed in the set_ftrace_pid file forks.

   - Exposure of "maxactive" for kretprobe in kprobe_events

   - Allow for builtin init functions to be traced by the function
     tracer (via the kernel command line). Module init function tracing
     will come in the next release.

   - Added more selftests, and have selftests also test in an instance"

* tag 'trace-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (60 commits)
  ring-buffer: Return reader page back into existing ring buffer
  selftests: ftrace: Allow some event trigger tests to run in an instance
  selftests: ftrace: Have some basic tests run in a tracing instance too
  selftests: ftrace: Have event tests also run in an tracing instance
  selftests: ftrace: Make func_event_triggers and func_traceonoff_triggers tests do instances
  selftests: ftrace: Allow some tests to be run in a tracing instance
  tracing/ftrace: Allow for instances to trigger their own stacktrace probes
  tracing/ftrace: Allow for the traceonoff probe be unique to instances
  tracing/ftrace: Enable snapshot function trigger to work with instances
  tracing/ftrace: Allow instances to have their own function probes
  tracing/ftrace: Add a better way to pass data via the probe functions
  ftrace: Dynamically create the probe ftrace_ops for the trace_array
  tracing: Pass the trace_array into ftrace_probe_ops functions
  tracing: Have the trace_array hold the list of registered func probes
  ftrace: If the hash for a probe fails to update then free what was initialized
  ftrace: Have the function probes call their own function
  ftrace: Have each function probe use its own ftrace_ops
  ftrace: Have unregister_ftrace_function_probe_func() return a value
  ftrace: Add helper function ftrace_hash_move_and_update_ops()
  ftrace: Remove data field from ftrace_func_probe structure
  ...
2017-05-03 18:41:21 -07:00
Linus Torvalds
89c9fea3c8 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
  tty: fix comment for __tty_alloc_driver()
  init/main: properly align the multi-line comment
  init/main: Fix double "the" in comment
  Fix dead URLs to ftp.kernel.org
  drivers: Clean up duplicated email address
  treewide: Fix typo in xml/driver-api/basics.xml
  tools/testing/selftests/powerpc: remove redundant CFLAGS in Makefile: "-Wall -O2 -Wall" -> "-O2 -Wall"
  selftests/timers: Spelling s/privledges/privileges/
  HID: picoLCD: Spelling s/REPORT_WRTIE_MEMORY/REPORT_WRITE_MEMORY/
  net: phy: dp83848: Fix Typo
  UBI: Fix typos
  Documentation: ftrace.txt: Correct nice value of 120 priority
  net: fec: Fix typo in error msg and comment
  treewide: Fix typos in printk
2017-05-02 19:09:35 -07:00
Viresh Kumar
1b3b3b49b9 init/main: properly align the multi-line comment
Add a tab before it to follow standard practices. Also add the missing
full stop '.'.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-04-24 13:14:21 +02:00
Viresh Kumar
6623f1c615 init/main: Fix double "the" in comment
s/the\ the/the

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-04-24 13:14:21 +02:00
Nicolas Pitre
0c688614dc console: move console_init() out of tty_io.c
All the console driver handling code lives in printk.c.
Move console_init() there as well so console support can still be used
when the TTY code is configured out. No logical changes from this patch.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-18 18:01:52 +02:00
Steven Rostedt (VMware)
b80f0f6c9e ftrace: Have init/main.c call ftrace directly to free init memory
Relying on free_reserved_area() to call ftrace to free init memory proved to
not be sufficient. The issue is that on x86, when debug_pagealloc is
enabled, the init memory is not freed, but simply set as not present. Since
ftrace was uninformed of this, starting function tracing still tries to
update pages that are not present according to the page tables, causing
ftrace to bug, as well as killing the kernel itself.

Instead of relying on free_reserved_area(), have init/main.c call ftrace
directly just before it frees the init memory. Then it needs to use
__init_begin and __init_end to know where the init memory location is.
Looking at all archs (and testing what I can), it appears that this should
work for each of them.

Reported-by: kernel test robot <xiaolong.ye@intel.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-04-03 14:04:00 -04:00
Michal Hocko
597b7305dd mm: move mm_percpu_wq initialization earlier
Yang Li has reported that drain_all_pages triggers a WARN_ON which means
that this function is called earlier than the mm_percpu_wq is
initialized on arm64 with CMA configured:

  WARNING: CPU: 2 PID: 1 at mm/page_alloc.c:2423 drain_all_pages+0x244/0x25c
  Modules linked in:
  CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.11.0-rc1-next-20170310-00027-g64dfbc5 #127
  Hardware name: Freescale Layerscape 2088A RDB Board (DT)
  task: ffffffc07c4a6d00 task.stack: ffffffc07c4a8000
  PC is at drain_all_pages+0x244/0x25c
  LR is at start_isolate_page_range+0x14c/0x1f0
  [...]
   drain_all_pages+0x244/0x25c
   start_isolate_page_range+0x14c/0x1f0
   alloc_contig_range+0xec/0x354
   cma_alloc+0x100/0x1fc
   dma_alloc_from_contiguous+0x3c/0x44
   atomic_pool_init+0x7c/0x208
   arm64_dma_init+0x44/0x4c
   do_one_initcall+0x38/0x128
   kernel_init_freeable+0x1a0/0x240
   kernel_init+0x10/0xfc
   ret_from_fork+0x10/0x20

Fix this by moving the whole setup_vmstat which is an initcall right now
to init_mm_internals which will be called right after the WQ subsystem
is initialized.

Link: http://lkml.kernel.org/r/20170315164021.28532-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Yang Li <pku.leo@gmail.com>
Tested-by: Yang Li <pku.leo@gmail.com>
Tested-by: Xiaolong Ye <xiaolong.ye@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-31 17:13:30 -07:00
Steven Rostedt (VMware)
f631718de3 ftrace: Move ftrace_init() to right after memory initialization
Initialize the ftrace records immediately after memory initialization, as
that is all that is required for the records to be created. This will allow
for future work to get function tracing started earlier in the boot process.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-03-24 13:08:44 -04:00
Steven Rostedt (VMware)
e725c731e3 tracing: Split tracing initialization into two for early initialization
Create an early_trace_init() function that will initialize the buffers and
allow for ealier use of trace_printk(). This will also allow for future work
to have function tracing start earlier at boot up.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-03-24 13:08:43 -04:00
Linus Torvalds
84c37c168c Change get_random_{int,log} to use the CRNG used by /dev/urandom and
getrandom(2).  It's faster and arguably more secure than cut-down MD5
 that we had been using.
 
 Also do some code cleanup.
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Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random

Pull random updates from Ted Ts'o:
 "Change get_random_{int,log} to use the CRNG used by /dev/urandom and
  getrandom(2). It's faster and arguably more secure than cut-down MD5
  that we had been using.

  Also do some code cleanup"

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  random: move random_min_urandom_seed into CONFIG_SYSCTL ifdef block
  random: convert get_random_int/long into get_random_u32/u64
  random: use chacha20 for get_random_int/long
  random: fix comment for unused random_min_urandom_seed
  random: remove variable limit
  random: remove stale urandom_init_wait
  random: remove stale maybe_reseed_primary_crng
2017-03-11 09:08:47 -08:00
Ingo Molnar
1777e46355 sched/headers: Prepare to move _init() prototypes from <linux/sched.h> to <linux/sched/init.h>
But first introduce a trivial header and update usage sites.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:40 +01:00
Ingo Molnar
5c2c5c5514 sched/headers, vfs/execve: Prepare to move the do_execve*() prototypes from <linux/sched.h> to <linux/binfmts.h>
But first update the usage sites with the new header dependency.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:39 +01:00
Ingo Molnar
68db0cf106 sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h>
We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/task_stack.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:36 +01:00
Ingo Molnar
299300258d sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>
We are going to split <linux/sched/task.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/task.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:35 +01:00
Ingo Molnar
38b8d208a4 sched/headers: Prepare for new header dependencies before moving code to <linux/sched/nmi.h>
We are going to move softlockup APIs out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

<linux/nmi.h> already includes <linux/sched.h>.

Include the <linux/nmi.h> header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:30 +01:00
Linus Torvalds
cf393195c3 Merge branch 'idr-4.11' of git://git.infradead.org/users/willy/linux-dax
Pull IDR rewrite from Matthew Wilcox:
 "The most significant part of the following is the patch to rewrite the
  IDR & IDA to be clients of the radix tree. But there's much more,
  including an enhancement of the IDA to be significantly more space
  efficient, an IDR & IDA test suite, some improvements to the IDR API
  (and driver changes to take advantage of those improvements), several
  improvements to the radix tree test suite and RCU annotations.

  The IDR & IDA rewrite had a good spin in linux-next and Andrew's tree
  for most of the last cycle. Coupled with the IDR test suite, I feel
  pretty confident that any remaining bugs are quite hard to hit. 0-day
  did a great job of watching my git tree and pointing out problems; as
  it hit them, I added new test-cases to be sure not to be caught the
  same way twice"

Willy goes on to expand a bit on the IDR rewrite rationale:
 "The radix tree and the IDR use very similar data structures.

  Merging the two codebases lets us share the memory allocation pools,
  and results in a net deletion of 500 lines of code. It also opens up
  the possibility of exposing more of the features of the radix tree to
  users of the IDR (and I have some interesting patches along those
  lines waiting for 4.12)

  It also shrinks the size of the 'struct idr' from 40 bytes to 24 which
  will shrink a fair few data structures that embed an IDR"

* 'idr-4.11' of git://git.infradead.org/users/willy/linux-dax: (32 commits)
  radix tree test suite: Add config option for map shift
  idr: Add missing __rcu annotations
  radix-tree: Fix __rcu annotations
  radix-tree: Add rcu_dereference and rcu_assign_pointer calls
  radix tree test suite: Run iteration tests for longer
  radix tree test suite: Fix split/join memory leaks
  radix tree test suite: Fix leaks in regression2.c
  radix tree test suite: Fix leaky tests
  radix tree test suite: Enable address sanitizer
  radix_tree_iter_resume: Fix out of bounds error
  radix-tree: Store a pointer to the root in each node
  radix-tree: Chain preallocated nodes through ->parent
  radix tree test suite: Dial down verbosity with -v
  radix tree test suite: Introduce kmalloc_verbose
  idr: Return the deleted entry from idr_remove
  radix tree test suite: Build separate binaries for some tests
  ida: Use exceptional entries for small IDAs
  ida: Move ida_bitmap to a percpu variable
  Reimplement IDR and IDA using the radix tree
  radix-tree: Add radix_tree_iter_delete
  ...
2017-02-28 20:29:41 -08:00
Jinbum Park
2959a5f726 mm: add arch-independent testcases for RODATA
This patch makes arch-independent testcases for RODATA.  Both x86 and
x86_64 already have testcases for RODATA, But they are arch-specific
because using inline assembly directly.

And cacheflush.h is not a suitable location for rodata-test related
things.  Since they were in cacheflush.h, If someone change the state of
CONFIG_DEBUG_RODATA_TEST, It cause overhead of kernel build.

To solve the above issues, write arch-independent testcases and move it
to shared location.

[jinb.park7@gmail.com: fix config dependency]
  Link: http://lkml.kernel.org/r/20170209131625.GA16954@pjb1027-Latitude-E5410
Link: http://lkml.kernel.org/r/20170129105436.GA9303@pjb1027-Latitude-E5410
Signed-off-by: Jinbum Park <jinb.park7@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Valentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-27 18:43:48 -08:00
Lokesh Vutla
0886551480 initramfs: finish fput() before accessing any binary from initramfs
Commit 4a9d4b024a ("switch fput to task_work_add") implements a
schedule_work() for completing fput(), but did not guarantee calling
__fput() after unpacking initramfs.  Because of this, there is a
possibility that during boot a driver can see ETXTBSY when it tries to
load a binary from initramfs as fput() is still pending on that binary.

This patch makes sure that fput() is completed after unpacking initramfs
and removes the call to flush_delayed_fput() in kernel_init() which
happens very late after unpacking initramfs.

Link: http://lkml.kernel.org/r/20170201140540.22051-1-lokeshvutla@ti.com
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Reported-by: Murali Karicheri <m-karicheri2@ti.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tero Kristo <t-kristo@ti.com>
Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Nishanth Menon <nm@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-27 18:43:46 -08:00
Linus Torvalds
7d91de7443 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk
Pull printk updates from Petr Mladek:

 - Add Petr Mladek, Sergey Senozhatsky as printk maintainers, and Steven
   Rostedt as the printk reviewer. This idea came up after the
   discussion about printk issues at Kernel Summit. It was formulated
   and discussed at lkml[1].

 - Extend a lock-less NMI per-cpu buffers idea to handle recursive
   printk() calls by Sergey Senozhatsky[2]. It is the first step in
   sanitizing printk as discussed at Kernel Summit.

   The change allows to see messages that would normally get ignored or
   would cause a deadlock.

   Also it allows to enable lockdep in printk(). This already paid off.
   The testing in linux-next helped to discover two old problems that
   were hidden before[3][4].

 - Remove unused parameter by Sergey Senozhatsky. Clean up after a past
   change.

[1] http://lkml.kernel.org/r/1481798878-31898-1-git-send-email-pmladek@suse.com
[2] http://lkml.kernel.org/r/20161227141611.940-1-sergey.senozhatsky@gmail.com
[3] http://lkml.kernel.org/r/20170215044332.30449-1-sergey.senozhatsky@gmail.com
[4] http://lkml.kernel.org/r/20170217015932.11898-1-sergey.senozhatsky@gmail.com

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
  printk: drop call_console_drivers() unused param
  printk: convert the rest to printk-safe
  printk: remove zap_locks() function
  printk: use printk_safe buffers in printk
  printk: report lost messages in printk safe/nmi contexts
  printk: always use deferred printk when flush printk_safe lines
  printk: introduce per-cpu safe_print seq buffer
  printk: rename nmi.c and exported api
  printk: use vprintk_func in vprintk()
  MAINTAINERS: Add printk maintainers
2017-02-22 17:33:34 -08:00
Linus Torvalds
7bb033829e This renames the (now inaccurate) CONFIG_DEBUG_RODATA and related config
CONFIG_SET_MODULE_RONX to the more sensible CONFIG_STRICT_KERNEL_RWX and
 CONFIG_STRICT_MODULE_RWX.
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Merge tag 'rodata-v4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull rodata updates from Kees Cook:
 "This renames the (now inaccurate) DEBUG_RODATA and related
  SET_MODULE_RONX configs to the more sensible STRICT_KERNEL_RWX and
  STRICT_MODULE_RWX"

* tag 'rodata-v4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  arch: Rename CONFIG_DEBUG_RODATA and CONFIG_DEBUG_MODULE_RONX
  arch: Move CONFIG_DEBUG_RODATA and CONFIG_SET_MODULE_RONX to be common
2017-02-21 17:56:45 -08:00
Linus Torvalds
6d1c42d9b9 Final extable.h related changes.
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Merge tag 'extable-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

Pull exception table module split from Paul Gortmaker:
 "Final extable.h related changes.

  This completes the separation of exception table content from the
  module.h header file. This is achieved with the final commit that
  removes the one line back compatible change that sourced extable.h
  into the module.h file.

  The commits are unchanged since January, with the exception of a
  couple Acks that came in for the last two commits a bit later. The
  changes have been in linux-next for quite some time[1] and have got
  widespread arch coverage via toolchains I have and also from
  additional ones the kbuild bot has.

  Maintaners of the various arch were Cc'd during the postings to
  lkml[2] and informed that the intention was to take the remaining arch
  specific changes and lump them together with the final two non-arch
  specific changes and submit for this merge window.

  The ia64 diffstat stands out and probably warrants a mention. In an
  earlier review, Al Viro made a valid comment that the original header
  separation of content left something to be desired, and that it get
  fixed as a part of this change, hence the larger diffstat"

* tag 'extable-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (21 commits)
  module.h: remove extable.h include now users have migrated
  core: migrate exception table users off module.h and onto extable.h
  cris: migrate exception table users off module.h and onto extable.h
  hexagon: migrate exception table users off module.h and onto extable.h
  microblaze: migrate exception table users off module.h and onto extable.h
  unicore32: migrate exception table users off module.h and onto extable.h
  score: migrate exception table users off module.h and onto extable.h
  metag: migrate exception table users off module.h and onto extable.h
  arc: migrate exception table users off module.h and onto extable.h
  nios2: migrate exception table users off module.h and onto extable.h
  sparc: migrate exception table users onto extable.h
  openrisc: migrate exception table users off module.h and onto extable.h
  frv: migrate exception table users off module.h and onto extable.h
  sh: migrate exception table users off module.h and onto extable.h
  xtensa: migrate exception table users off module.h and onto extable.h
  mn10300: migrate exception table users off module.h and onto extable.h
  alpha: migrate exception table users off module.h and onto extable.h
  arm: migrate exception table users off module.h and onto extable.h
  m32r: migrate exception table users off module.h and onto extable.h
  ia64: ensure exception table search users include extable.h
  ...
2017-02-21 14:28:55 -08:00
Linus Torvalds
828cad8ea0 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
 "The main changes in this (fairly busy) cycle were:

   - There was a class of scheduler bugs related to forgetting to update
     the rq-clock timestamp which can cause weird and hard to debug
     problems, so there's a new debug facility for this: which uncovered
     a whole lot of bugs which convinced us that we want to keep the
     debug facility.

     (Peter Zijlstra, Matt Fleming)

   - Various cputime related updates: eliminate cputime and use u64
     nanoseconds directly, simplify and improve the arch interfaces,
     implement delayed accounting more widely, etc. - (Frederic
     Weisbecker)

   - Move code around for better structure plus cleanups (Ingo Molnar)

   - Move IO schedule accounting deeper into the scheduler plus related
     changes to improve the situation (Tejun Heo)

   - ... plus a round of sched/rt and sched/deadline fixes, plus other
     fixes, updats and cleanups"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (85 commits)
  sched/core: Remove unlikely() annotation from sched_move_task()
  sched/autogroup: Rename auto_group.[ch] to autogroup.[ch]
  sched/topology: Split out scheduler topology code from core.c into topology.c
  sched/core: Remove unnecessary #include headers
  sched/rq_clock: Consolidate the ordering of the rq_clock methods
  delayacct: Include <uapi/linux/taskstats.h>
  sched/core: Clean up comments
  sched/rt: Show the 'sched_rr_timeslice' SCHED_RR timeslice tuning knob in milliseconds
  sched/clock: Add dummy clear_sched_clock_stable() stub function
  sched/cputime: Remove generic asm headers
  sched/cputime: Remove unused nsec_to_cputime()
  s390, sched/cputime: Remove unused cputime definitions
  powerpc, sched/cputime: Remove unused cputime definitions
  s390, sched/cputime: Make arch_cpu_idle_time() to return nsecs
  ia64, sched/cputime: Remove unused cputime definitions
  ia64: Convert vtime to use nsec units directly
  ia64, sched/cputime: Move the nsecs based cputime headers to the last arch using it
  sched/cputime: Remove jiffies based cputime
  sched/cputime, vtime: Return nsecs instead of cputime_t to account
  sched/cputime: Complete nsec conversion of tick based accounting
  ...
2017-02-20 12:52:55 -08:00
Matthew Wilcox
0a835c4f09 Reimplement IDR and IDA using the radix tree
The IDR is very similar to the radix tree.  It has some functionality that
the radix tree did not have (alloc next free, cyclic allocation, a
callback-based for_each, destroy tree), which is readily implementable on
top of the radix tree.  A few small changes were needed in order to use a
tag to represent nodes with free space below them.  More extensive
changes were needed to support storing NULL as a valid entry in an IDR.
Plain radix trees still interpret NULL as a not-present entry.

The IDA is reimplemented as a client of the newly enhanced radix tree.  As
in the current implementation, it uses a bitmap at the last level of the
tree.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2017-02-13 21:44:01 -05:00
Paul Gortmaker
8a293be0d6 core: migrate exception table users off module.h and onto extable.h
These files were including module.h for exception table related
functions.  We've now separated that content out into its own file
"extable.h" so now move over to that and where possible, avoid all
the extra header content in module.h that we don't really need to
compile these non-modular files.

Note:
   init/main.c still needs module.h for __init_or_module
   kernel/extable.c still needs module.h for is_module_text_address

...and so we don't get the benefit of removing module.h from the cpp
feed for these two files, unlike the almost universal 1:1 exchange
of module.h for extable.h we were able to do in the arch dirs.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Jessica Yu <jeyu@redhat.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2017-02-09 16:38:53 -05:00
Sergey Senozhatsky
f92bac3b14 printk: rename nmi.c and exported api
A preparation patch for printk_safe work. No functional change.
- rename nmi.c to print_safe.c
- add `printk_safe' prefix to some (which used both by printk-safe
  and printk-nmi) of the exported functions.

Link: http://lkml.kernel.org/r/20161227141611.940-3-sergey.senozhatsky@gmail.com
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Tejun Heo <tj@kernel.org>
Cc: Calvin Owens <calvinowens@fb.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2017-02-08 11:02:33 +01:00
Laura Abbott
0f5bf6d0af arch: Rename CONFIG_DEBUG_RODATA and CONFIG_DEBUG_MODULE_RONX
Both of these options are poorly named. The features they provide are
necessary for system security and should not be considered debug only.
Change the names to CONFIG_STRICT_KERNEL_RWX and
CONFIG_STRICT_MODULE_RWX to better describe what these options do.

Signed-off-by: Laura Abbott <labbott@redhat.com>
Acked-by: Jessica Yu <jeyu@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2017-02-07 12:32:52 -08:00
Dave Young
7b0a911478 efi/x86: Move the EFI BGRT init code to early init code
Before invoking the arch specific handler, efi_mem_reserve() reserves
the given memory region through memblock.

efi_bgrt_init() will call efi_mem_reserve() after mm_init(), at which
time memblock is dead and should not be used anymore.

The EFI BGRT code depends on ACPI initialization to get the BGRT ACPI
table, so move parsing of the BGRT table to ACPI early boot code to
ensure that efi_mem_reserve() in EFI BGRT code still use memblock safely.

Tested-by: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-acpi@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1485868902-20401-9-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-01 08:45:46 +01:00
Jason A. Donenfeld
f5b98461cb random: use chacha20 for get_random_int/long
Now that our crng uses chacha20, we can rely on its speedy
characteristics for replacing MD5, while simultaneously achieving a
higher security guarantee. Before the idea was to use these functions if
you wanted random integers that aren't stupidly insecure but aren't
necessarily secure either, a vague gray zone, that hopefully was "good
enough" for its users. With chacha20, we can strengthen this claim,
since either we're using an rdrand-like instruction, or we're using the
same crng as /dev/urandom. And it's faster than what was before.

We could have chosen to replace this with a SipHash-derived function,
which might be slightly faster, but at the cost of having yet another
RNG construction in the kernel. By moving to chacha20, we have a single
RNG to analyze and verify, and we also already get good performance
improvements on all platforms.

Implementation-wise, rather than use a generic buffer for both
get_random_int/long and memcpy based on the size needs, we use a
specific buffer for 32-bit reads and for 64-bit reads. This way, we're
guaranteed to always have aligned accesses on all platforms. While
slightly more verbose in C, the assembly this generates is a lot
simpler than otherwise.

Finally, on 32-bit platforms where longs and ints are the same size,
we simply alias get_random_int to get_random_long.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Suggested-by: Theodore Ts'o <tytso@mit.edu>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-01-27 14:25:06 -05:00
Peter Zijlstra
9881b024b7 sched/clock: Delay switching sched_clock to stable
Currently we switch to the stable sched_clock if we guess the TSC is
usable, and then switch back to the unstable path if it turns out TSC
isn't stable during SMP bringup after all.

Delay switching to the stable path until after SMP bringup is
complete. This way we'll avoid switching during the time we detect the
worst of the TSC offences.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14 11:29:59 +01:00
Nicholas Piggin
6290602709 mm: add PageWaiters indicating tasks are waiting for a page bit
Add a new page flag, PageWaiters, to indicate the page waitqueue has
tasks waiting. This can be tested rather than testing waitqueue_active
which requires another cacheline load.

This bit is always set when the page has tasks on page_waitqueue(page),
and is set and cleared under the waitqueue lock. It may be set when
there are no tasks on the waitqueue, which will cause a harmless extra
wakeup check that will clears the bit.

The generic bit-waitqueue infrastructure is no longer used for pages.
Instead, waitqueues are used directly with a custom key type. The
generic code was not flexible enough to have PageWaiters manipulation
under the waitqueue lock (which simplifies concurrency).

This improves the performance of page lock intensive microbenchmarks by
2-3%.

Putting two bits in the same word opens the opportunity to remove the
memory barrier between clearing the lock bit and testing the waiters
bit, after some work on the arch primitives (e.g., ensuring memory
operand widths match and cover both bits).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Lutomirski <luto@kernel.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-25 11:54:48 -08:00
Linus Torvalds
4d98ead183 Modules updates for v4.10
Summary of modules changes for the 4.10 merge window:
 
 * The rodata= cmdline parameter has been extended to additionally
   apply to module mappings
 
 * Fix a hard to hit race between module loader error/clean up
   handling and ftrace registration
 
 * Some code cleanups, notably panic.c and modules code use a
   unified taint_flags table now. This is much cleaner than
   duplicating the taint flag code in modules.c
 
 Signed-off-by: Jessica Yu <jeyu@redhat.com>
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Merge tag 'modules-for-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux

Pull modules updates from Jessica Yu:
 "Summary of modules changes for the 4.10 merge window:

   - The rodata= cmdline parameter has been extended to additionally
     apply to module mappings

   - Fix a hard to hit race between module loader error/clean up
     handling and ftrace registration

   - Some code cleanups, notably panic.c and modules code use a unified
     taint_flags table now. This is much cleaner than duplicating the
     taint flag code in modules.c"

* tag 'modules-for-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  module: fix DEBUG_SET_MODULE_RONX typo
  module: extend 'rodata=off' boot cmdline parameter to module mappings
  module: Fix a comment above strong_try_module_get()
  module: When modifying a module's text ignore modules which are going away too
  module: Ensure a module's state is set accordingly during module coming cleanup code
  module: remove trailing whitespace
  taint/module: Clean up global and module taint flags handling
  modpost: free allocated memory
2016-12-14 20:12:43 -08:00
Linus Torvalds
c11a6cfb01 Merge branch 'for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue updates from Tejun Heo:
 "Mostly patches to initialize workqueue subsystem earlier and get rid
  of keventd_up().

  The patches were headed for the last merge cycle but got delayed due
  to a bug found late minute, which is fixed now.

  Also, to help debugging, destroy_workqueue() is more chatty now on a
  sanity check failure."

* 'for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: move wq_numa_init() to workqueue_init()
  workqueue: remove keventd_up()
  debugobj, workqueue: remove keventd_up() usage
  slab, workqueue: remove keventd_up() usage
  power, workqueue: remove keventd_up() usage
  tty, workqueue: remove keventd_up() usage
  mce, workqueue: remove keventd_up() usage
  workqueue: make workqueue available early during boot
  workqueue: dump workqueue state on sanity check failures in destroy_workqueue()
2016-12-13 12:59:57 -08:00
Linus Torvalds
e7aa8c2eb1 These are the documentation changes for 4.10.
It's another busy cycle for the docs tree, as the sphinx conversion
 continues.  Highlights include:
 
  - Further work on PDF output, which remains a bit of a pain but should be
    more solid now.
 
  - Five more DocBook template files converted to Sphinx.  Only 27 to go...
    Lots of plain-text files have also been converted and integrated.
 
  - Images in binary formats have been replaced with more source-friendly
    versions.
 
  - Various bits of organizational work, including the renaming of various
    files discussed at the kernel summit.
 
  - New documentation for the device_link mechanism.
 
 ...and, of course, lots of typo fixes and small updates.
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Merge tag 'docs-4.10' of git://git.lwn.net/linux

Pull documentation update from Jonathan Corbet:
 "These are the documentation changes for 4.10.

  It's another busy cycle for the docs tree, as the sphinx conversion
  continues. Highlights include:

   - Further work on PDF output, which remains a bit of a pain but
     should be more solid now.

   - Five more DocBook template files converted to Sphinx. Only 27 to
     go... Lots of plain-text files have also been converted and
     integrated.

   - Images in binary formats have been replaced with more
     source-friendly versions.

   - Various bits of organizational work, including the renaming of
     various files discussed at the kernel summit.

   - New documentation for the device_link mechanism.

  ... and, of course, lots of typo fixes and small updates"

* tag 'docs-4.10' of git://git.lwn.net/linux: (193 commits)
  dma-buf: Extract dma-buf.rst
  Update Documentation/00-INDEX
  docs: 00-INDEX: document directories/files with no docs
  docs: 00-INDEX: remove non-existing entries
  docs: 00-INDEX: add missing entries for documentation files/dirs
  docs: 00-INDEX: consolidate process/ and admin-guide/ description
  scripts: add a script to check if Documentation/00-INDEX is sane
  Docs: change sh -> awk in REPORTING-BUGS
  Documentation/core-api/device_link: Add initial documentation
  core-api: remove an unexpected unident
  ppc/idle: Add documentation for powersave=off
  Doc: Correct typo, "Introdution" => "Introduction"
  Documentation/atomic_ops.txt: convert to ReST markup
  Documentation/local_ops.txt: convert to ReST markup
  Documentation/assoc_array.txt: convert to ReST markup
  docs-rst: parse-headers.pl: cleanup the documentation
  docs-rst: fix media cleandocs target
  docs-rst: media/Makefile: reorganize the rules
  docs-rst: media: build SVG from graphviz files
  docs-rst: replace bayer.png by a SVG image
  ...
2016-12-12 21:58:13 -08:00
Thomas Gleixner
e7ff3a4763 x86/amd: Check for the C1E bug post ACPI subsystem init
AMD CPUs affected by the E400 erratum suffer from the issue that the
local APIC timer stops when the CPU goes into C1E. Unfortunately there
is no way to detect the affected CPUs on early boot. It's only possible
to determine the range of possibly affected CPUs from the family/model
range.

The actual decision whether to enter C1E and thus cause the bug is done
by the firmware and we need to detect that case late, after ACPI has
been initialized.

The current solution is to check in the idle routine whether the CPU is
affected by reading the MSR_K8_INT_PENDING_MSG MSR and checking for the
K8_INTP_C1E_ACTIVE_MASK bits. If one of the bits is set then the CPU is
affected and the system is switched into forced broadcast mode.

This is ineffective and on non-affected CPUs every entry to idle does
the extra RDMSR.

After doing some research it turns out that the bits are visible on the
boot CPU right after the ACPI subsystem is initialized in the early
boot process. So instead of polling for the bits in the idle loop, add
a detection function after acpi_subsystem_init() and check for the MSR
bits. If set, then the X86_BUG_AMD_APIC_C1E is set on the boot CPU and
the TSC is marked unstable when X86_FEATURE_NONSTOP_TSC is not set as it
will stop in C1E state as well.

The switch to broadcast mode cannot be done at this point because the
boot CPU still uses HPET as a clockevent device and the local APIC timer
is not yet calibrated and installed. The switch to broadcast mode on the
affected CPUs needs to be done when the local APIC timer is actually set
up.

This allows to cleanup the amd_e400_idle() function in the next step.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20161209182912.2726-4-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-09 21:23:21 +01:00
Arnd Bergmann
4d217a5adc module: fix DEBUG_SET_MODULE_RONX typo
The newly added 'rodata_enabled' global variable is protected by
the wrong #ifdef, leading to a link error when CONFIG_DEBUG_SET_MODULE_RONX
is turned on:

kernel/module.o: In function `disable_ro_nx':
module.c:(.text.unlikely.disable_ro_nx+0x88): undefined reference to `rodata_enabled'
kernel/module.o: In function `module_disable_ro':
module.c:(.text.module_disable_ro+0x8c): undefined reference to `rodata_enabled'
kernel/module.o: In function `module_enable_ro':
module.c:(.text.module_enable_ro+0xb0): undefined reference to `rodata_enabled'

CONFIG_SET_MODULE_RONX does not exist, so use the correct one instead.

Fixes: 39290b389e ("module: extend 'rodata=off' boot cmdline parameter to module mappings")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jessica Yu <jeyu@redhat.com>
2016-11-28 11:37:57 -08:00
AKASHI Takahiro
39290b389e module: extend 'rodata=off' boot cmdline parameter to module mappings
The current "rodata=off" parameter disables read-only kernel mappings
under CONFIG_DEBUG_RODATA:
    commit d2aa1acad2 ("mm/init: Add 'rodata=off' boot cmdline parameter
    to disable read-only kernel mappings")

This patch is a logical extension to module mappings ie. read-only mappings
at module loading can be disabled even if CONFIG_DEBUG_SET_MODULE_RONX
(mainly for debug use). Please note, however, that it only affects RO/RW
permissions, keeping NX set.

This is the first step to make CONFIG_DEBUG_SET_MODULE_RONX mandatory
(always-on) in the future as CONFIG_DEBUG_RODATA on x86 and arm64.

Suggested-by: and Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Link: http://lkml.kernel.org/r/20161114061505.15238-1-takahiro.akashi@linaro.org
Signed-off-by: Jessica Yu <jeyu@redhat.com>
2016-11-27 16:15:33 -08:00
Mauro Carvalho Chehab
8c27ceff36 docs: fix locations of several documents that got moved
The previous patch renamed several files that are cross-referenced
along the Kernel documentation. Adjust the links to point to
the right places.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-10-24 08:12:35 -02:00
Tejun Heo
8bc4a04455 Merge branch 'for-4.9' into for-4.10 2016-10-19 12:12:40 -04:00
Emese Revfy
38addce8b6 gcc-plugins: Add latent_entropy plugin
This adds a new gcc plugin named "latent_entropy". It is designed to
extract as much possible uncertainty from a running system at boot time as
possible, hoping to capitalize on any possible variation in CPU operation
(due to runtime data differences, hardware differences, SMP ordering,
thermal timing variation, cache behavior, etc).

At the very least, this plugin is a much more comprehensive example for
how to manipulate kernel code using the gcc plugin internals.

The need for very-early boot entropy tends to be very architecture or
system design specific, so this plugin is more suited for those sorts
of special cases. The existing kernel RNG already attempts to extract
entropy from reliable runtime variation, but this plugin takes the idea to
a logical extreme by permuting a global variable based on any variation
in code execution (e.g. a different value (and permutation function)
is used to permute the global based on loop count, case statement,
if/then/else branching, etc).

To do this, the plugin starts by inserting a local variable in every
marked function. The plugin then adds logic so that the value of this
variable is modified by randomly chosen operations (add, xor and rol) and
random values (gcc generates separate static values for each location at
compile time and also injects the stack pointer at runtime). The resulting
value depends on the control flow path (e.g., loops and branches taken).

Before the function returns, the plugin mixes this local variable into
the latent_entropy global variable. The value of this global variable
is added to the kernel entropy pool in do_one_initcall() and _do_fork(),
though it does not credit any bytes of entropy to the pool; the contents
of the global are just used to mix the pool.

Additionally, the plugin can pre-initialize arrays with build-time
random contents, so that two different kernel builds running on identical
hardware will not have the same starting values.

Signed-off-by: Emese Revfy <re.emese@gmail.com>
[kees: expanded commit message and code comments]
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-10-10 14:51:44 -07:00
Tejun Heo
3347fa0928 workqueue: make workqueue available early during boot
Workqueue is currently initialized in an early init call; however,
there are cases where early boot code has to be split and reordered to
come after workqueue initialization or the same code path which makes
use of workqueues is used both before workqueue initailization and
after.  The latter cases have to gate workqueue usages with
keventd_up() tests, which is nasty and easy to get wrong.

Workqueue usages have become widespread and it'd be a lot more
convenient if it can be used very early from boot.  This patch splits
workqueue initialization into two steps.  workqueue_init_early() which
sets up the basic data structures so that workqueues can be created
and work items queued, and workqueue_init() which actually brings up
workqueues online and starts executing queued work items.  The former
step can be done very early during boot once memory allocation,
cpumasks and idr are initialized.  The latter right after kthreads
become available.

This allows work item queueing and canceling from very early boot
which is what most of these use cases want.

* As systemd_wq being initialized doesn't indicate that workqueue is
  fully online anymore, update keventd_up() to test wq_online instead.
  The follow-up patches will get rid of all its usages and the
  function itself.

* Flushing doesn't make sense before workqueue is fully initialized.
  The flush functions trigger WARN and return immediately before fully
  online.

* Work items are never in-flight before fully online.  Canceling can
  always succeed by skipping the flush step.

* Some code paths can no longer assume to be called with irq enabled
  as irq is disabled during early boot.  Use irqsave/restore
  operations instead.

v2: Watchdog init, which requires timer to be running, moved from
    workqueue_init_early() to workqueue_init().

Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/CA+55aFx0vPuMuxn00rBSM192n-Du5uxy+4AvKa0SBSOVJeuCGg@mail.gmail.com
2016-09-17 13:18:21 -04:00
Prarit Bhargava
841c06d71e init: allow blacklisting of module_init functions
sprint_symbol_no_offset() returns the string "function_name
[module_name]" where [module_name] is not printed for built in kernel
functions.  This means that the blacklisting code will fail when
comparing module function names with the extended string.

This patch adds the functionality to block a module's module_init()
function by finding the space in the string and truncating the
comparison to that length.

Link: http://lkml.kernel.org/r/1466124387-20446-1-git-send-email-prarit@redhat.com
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yang Shi <yang.shi@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:40 -04:00
Fabian Frederick
bd721ea73e treewide: replace obsolete _refok by __ref
There was only one use of __initdata_refok and __exit_refok

__init_refok was used 46 times against 82 for __ref.

Those definitions are obsolete since commit 312b1485fb ("Introduce new
section reference annotations tags: __ref, __refdata, __refconst")

This patch removes the following compatibility definitions and replaces
them treewide.

/* compatibility defines */
#define __init_refok     __ref
#define __initdata_refok __refdata
#define __exit_refok     __ref

I can also provide separate patches if necessary.
(One patch per tree and check in 1 month or 2 to remove old definitions)

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/1466796271-3043-1-git-send-email-fabf@skynet.be
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Linus Torvalds
086e3eb65e Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "Two weeks worth of fixes here"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (41 commits)
  init/main.c: fix initcall_blacklisted on ia64, ppc64 and parisc64
  autofs: don't get stuck in a loop if vfs_write() returns an error
  mm/page_owner: avoid null pointer dereference
  tools/vm/slabinfo: fix spelling mistake: "Ocurrences" -> "Occurrences"
  fs/nilfs2: fix potential underflow in call to crc32_le
  oom, suspend: fix oom_reaper vs. oom_killer_disable race
  ocfs2: disable BUG assertions in reading blocks
  mm, compaction: abort free scanner if split fails
  mm: prevent KASAN false positives in kmemleak
  mm/hugetlb: clear compound_mapcount when freeing gigantic pages
  mm/swap.c: flush lru pvecs on compound page arrival
  memcg: css_alloc should return an ERR_PTR value on error
  memcg: mem_cgroup_migrate() may be called with irq disabled
  hugetlb: fix nr_pmds accounting with shared page tables
  Revert "mm: disable fault around on emulated access bit architecture"
  Revert "mm: make faultaround produce old ptes"
  mailmap: add Boris Brezillon's email
  mailmap: add Antoine Tenart's email
  mm, sl[au]b: add __GFP_ATOMIC to the GFP reclaim mask
  mm: mempool: kasan: don't poot mempool objects in quarantine
  ...
2016-06-24 19:08:33 -07:00
Rasmus Villemoes
0fd5ed8d89 init/main.c: fix initcall_blacklisted on ia64, ppc64 and parisc64
When I replaced kasprintf("%pf") with a direct call to
sprint_symbol_no_offset I must have broken the initcall blacklisting
feature on the arches where dereference_function_descriptor() is
non-trivial.

Fixes: c8cdd2be21 (init/main.c: simplify initcall_blacklisted())
Link: http://lkml.kernel.org/r/1466027283-4065-1-git-send-email-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Yang Shi <yang.shi@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Petr Mladek <pmladek@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-24 17:23:52 -07:00
Linus Torvalds
b235beea9e Clarify naming of thread info/stack allocators
We've had the thread info allocated together with the thread stack for
most architectures for a long time (since the thread_info was split off
from the task struct), but that is about to change.

But the patches that move the thread info to be off-stack (and a part of
the task struct instead) made it clear how confused the allocator and
freeing functions are.

Because the common case was that we share an allocation with the thread
stack and the thread_info, the two pointers were identical.  That
identity then meant that we would have things like

	ti = alloc_thread_info_node(tsk, node);
	...
	tsk->stack = ti;

which certainly _worked_ (since stack and thread_info have the same
value), but is rather confusing: why are we assigning a thread_info to
the stack? And if we move the thread_info away, the "confusing" code
just gets to be entirely bogus.

So remove all this confusion, and make it clear that we are doing the
stack allocation by renaming and clarifying the function names to be
about the stack.  The fact that the thread_info then shares the
allocation is an implementation detail, and not really about the
allocation itself.

This is a pure renaming and type fix: we pass in the same pointer, it's
just that we clarify what the pointer means.

The ia64 code that actually only has one single allocation (for all of
task_struct, thread_info and kernel thread stack) now looks a bit odd,
but since "tsk->stack" is actually not even used there, that oddity
doesn't matter.  It would be a separate thing to clean that up, I
intentionally left the ia64 changes as a pure brute-force renaming and
type change.

Acked-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-24 15:09:37 -07:00
Yang Shi
fe53ca5427 mm: use early_pfn_to_nid in page_ext_init
page_ext_init() checks suitable pages with pfn_to_nid(), but
pfn_to_nid() depends on memmap which will not be setup fully until
page_alloc_init_late() is done.  Use early_pfn_to_nid() instead of
pfn_to_nid() so that page extension could be still used early even
though CONFIG_ DEFERRED_STRUCT_PAGE_INIT is enabled and catch early page
allocation call sites.

Suggested by Joonsoo Kim [1], this fix basically undoes the change
introduced by commit b8f1a75d61 ("mm: call page_ext_init() after all
struct pages are initialized") and fixes the same problem with a better
approach.

[1] http://lkml.kernel.org/r/CAAmzW4OUmyPwQjvd7QUfc6W1Aic__TyAuH80MLRZNMxKy0-wPQ@mail.gmail.com

Link: http://lkml.kernel.org/r/1464198689-23458-1-git-send-email-yang.shi@linaro.org
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-27 14:49:37 -07:00
Rasmus Villemoes
c8cdd2be21 init/main.c: simplify initcall_blacklisted()
Using kasprintf to get the function name makes us look up the name
twice, along with all the vsnprintf overhead of parsing the format
string etc.  It also means there is an allocation failure case to deal
with.  Since symbol_string in vsprintf.c would anyway allocate an array
of size KSYM_SYMBOL_LEN on the stack, that might as well be done up
here.

Moreover, since this is a debug feature and the blacklisted_initcalls
list is usually empty, we might as well test that and thus avoid looking
up the symbol name even once in the common case.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Prarit Bhargava <prarit@redhat.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>
2016-05-20 17:58:30 -07:00
Petr Mladek
42a0bb3f71 printk/nmi: generic solution for safe printk in NMI
printk() takes some locks and could not be used a safe way in NMI
context.

The chance of a deadlock is real especially when printing stacks from
all CPUs.  This particular problem has been addressed on x86 by the
commit a9edc88093 ("x86/nmi: Perform a safe NMI stack trace on all
CPUs").

The patchset brings two big advantages.  First, it makes the NMI
backtraces safe on all architectures for free.  Second, it makes all NMI
messages almost safe on all architectures (the temporary buffer is
limited.  We still should keep the number of messages in NMI context at
minimum).

Note that there already are several messages printed in NMI context:
WARN_ON(in_nmi()), BUG_ON(in_nmi()), anything being printed out from MCE
handlers.  These are not easy to avoid.

This patch reuses most of the code and makes it generic.  It is useful
for all messages and architectures that support NMI.

The alternative printk_func is set when entering and is reseted when
leaving NMI context.  It queues IRQ work to copy the messages into the
main ring buffer in a safe context.

__printk_nmi_flush() copies all available messages and reset the buffer.
Then we could use a simple cmpxchg operations to get synchronized with
writers.  There is also used a spinlock to get synchronized with other
flushers.

We do not longer use seq_buf because it depends on external lock.  It
would be hard to make all supported operations safe for a lockless use.
It would be confusing and error prone to make only some operations safe.

The code is put into separate printk/nmi.c as suggested by Steven
Rostedt.  It needs a per-CPU buffer and is compiled only on
architectures that call nmi_enter().  This is achieved by the new
HAVE_NMI Kconfig flag.

The are MN10300 and Xtensa architectures.  We need to clean up NMI
handling there first.  Let's do it separately.

The patch is heavily based on the draft from Peter Zijlstra, see

  https://lkml.org/lkml/2015/6/10/327

[arnd@arndb.de: printk-nmi: use %zu format string for size_t]
[akpm@linux-foundation.org: min_t->min - all types are size_t here]
Signed-off-by: Petr Mladek <pmladek@suse.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Jan Kara <jack@suse.cz>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>	[arm part]
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jiri Kosina <jkosina@suse.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: David Miller <davem@davemloft.net>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-20 17:58:30 -07:00
Yang Shi
b8f1a75d61 mm: call page_ext_init() after all struct pages are initialized
When DEFERRED_STRUCT_PAGE_INIT is enabled, just a subset of memmap at
boot are initialized, then the rest are initialized in parallel by
starting one-off "pgdatinitX" kernel thread for each node X.

If page_ext_init is called before it, some pages will not have valid
extension, this may lead the below kernel oops when booting up kernel:

  BUG: unable to handle kernel NULL pointer dereference at           (null)
  IP: [<ffffffff8118d982>] free_pcppages_bulk+0x2d2/0x8d0
  PGD 0
  Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
  Modules linked in:
  CPU: 11 PID: 106 Comm: pgdatinit1 Not tainted 4.6.0-rc5-next-20160427 #26
  Hardware name: Intel Corporation S5520HC/S5520HC, BIOS S5500.86B.01.10.0025.030220091519 03/02/2009
  task: ffff88017c080040 ti: ffff88017c084000 task.ti: ffff88017c084000
  RIP: 0010:[<ffffffff8118d982>]  [<ffffffff8118d982>] free_pcppages_bulk+0x2d2/0x8d0
  RSP: 0000:ffff88017c087c48  EFLAGS: 00010046
  RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001
  RDX: 0000000000000980 RSI: 0000000000000080 RDI: 0000000000660401
  RBP: ffff88017c087cd0 R08: 0000000000000401 R09: 0000000000000009
  R10: ffff88017c080040 R11: 000000000000000a R12: 0000000000000400
  R13: ffffea0019810000 R14: ffffea0019810040 R15: ffff88066cfe6080
  FS:  0000000000000000(0000) GS:ffff88066cd40000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000000 CR3: 0000000002406000 CR4: 00000000000006e0
  Call Trace:
    free_hot_cold_page+0x192/0x1d0
    __free_pages+0x5c/0x90
    __free_pages_boot_core+0x11a/0x14e
    deferred_free_range+0x50/0x62
    deferred_init_memmap+0x220/0x3c3
    kthread+0xf8/0x110
    ret_from_fork+0x22/0x40
  Code: 49 89 d4 48 c1 e0 06 49 01 c5 e9 de fe ff ff 4c 89 f7 44 89 4d b8 4c 89 45 c0 44 89 5d c8 48 89 4d d0 e8 62 c7 07 00 48 8b 4d d0 <48> 8b 00 44 8b 5d c8 4c 8b 45 c0 44 8b 4d b8 a8 02 0f 84 05 ff
  RIP  [<ffffffff8118d982>] free_pcppages_bulk+0x2d2/0x8d0
   RSP <ffff88017c087c48>
  CR2: 0000000000000000

Move page_ext_init() after page_alloc_init_late() to make sure page extension
is setup for all pages.

Link: http://lkml.kernel.org/r/1463696006-31360-1-git-send-email-yang.shi@linaro.org
Signed-off-by: Yang Shi <yang.shi@linaro.org>
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>
2016-05-20 17:58:30 -07:00