xavi/android_kernel_m2note/drivers/tty, branch ng-7.1.2

mm/oom_kill: squashed reverts to a stable state

2019-07-18T22:08:32+00:00

Revert "mm, oom: fix use-after-free in oom_kill_process" This reverts commit e1bebdeedb497f03d426c85a89c3807c7e75268d. Signed-off-by: Corinna Vinschen Revert "mm,oom: make oom_killer_disable() killable" This reverts commit 65a7400a432639aa8d5e572f30687fbca204b6f8. Signed-off-by: Corinna Vinschen Revert "mm: oom_kill: don't ignore oom score on exiting tasks" This reverts commit d60dae46b27a8f381e4a7ad9dde870faa49fa5f1. Signed-off-by: Corinna Vinschen Revert "mm/oom_kill.c: avoid attempting to kill init sharing same memory" This reverts commit 10773c0325259d6640b93c0694b5598ddf84939f. Signed-off-by: Corinna Vinschen Revert "CHROMIUM: DROP: mm/oom_kill: Double-check before killing a child in our place" This reverts commit 2bdd9a2042a0e12d96c545773d9d8038c920f813. Revert "mm/oom_kill: fix the wrong task->mm == mm checks in oom_kill_process()" This reverts commit 419a313435b31821e4d045ca4b7ea1cc5fa02035. Signed-off-by: Corinna Vinschen Revert "mm/oom_kill: cleanup the "kill sharing same memory" loop" This reverts commit afda78c6de38f9f66eba0955153b380d540d8276. Revert "mm/oom_kill: remove the wrong fatal_signal_pending() check in oom_kill_process()" This reverts commit acde9c2ace298b249c06ec5b0b971c333449dc09. Signed-off-by: Corinna Vinschen Revert "mm, oom: remove task_lock protecting comm printing" This reverts commit 9a9ca142d250ec9de1215284857f4528c6ddb080. Signed-off-by: Corinna Vinschen Revert "mm/oom_kill.c: suppress unnecessary "sharing same memory" message" This reverts commit 1aa2960f7c70d65b1481f805ac73b988faff6747. Signed-off-by: Corinna Vinschen Revert "mm/oom_kill.c: reverse the order of setting TIF_MEMDIE and sending SIGKILL" This reverts commit f028aedfcfd2e2bb98921b98d3ae183387ab8fed. Revert "mm, oom: remove unnecessary variable" This reverts commit 54b0b58224146d68a11bccb5e64683ab3029373a. Revert "mm/oom_kill.c: print points as unsigned int" This reverts commit 603f975a6d4f0b56c7f6df7889ef2a704eca94a3. Signed-off-by: Corinna Vinschen Revert "mm: oom_kill: simplify OOM killer locking" This reverts commit 7951a52ed35d162063fa08b27894e302fd716ccd. Revert "mm: oom_kill: remove unnecessary locking in exit_oom_victim()" This reverts commit f0739b25ac884682865d6aae7485e79489107bfb. Revert "mm: oom_kill: generalize OOM progress waitqueue" This reverts commit eb4b1243c72ba0b392bbe05dbf9f91959f70eb18. Revert "mm: oom_kill: switch test-and-clear of known TIF_MEMDIE to clear" This reverts commit e611f16275c3642cb8a6345ff2470926fef52110. Revert "mm: oom_kill: clean up victim marking and exiting interfaces" This reverts commit c6fada01b9370e3d7603b4ad8c26b56759174667. Revert "mm: oom_kill: remove unnecessary locking in oom_enable()" This reverts commit 5dd152d7351b3805f59b2b1f624722ab2f3c5fd8. Revert "oom, PM: make OOM detection in the freezer path raceless" This reverts commit 5fc5b1ddee5404a7629dd7045f54eaf8941bc11c.

mm: oom_kill: simplify OOM killer locking

2019-07-08T11:36:44+00:00

The zonelist locking and the oom_sem are two overlapping locks that are used to serialize global OOM killing against different things. The historical zonelist locking serializes OOM kills from allocations with overlapping zonelists against each other to prevent killing more tasks than necessary in the same memory domain. Only when neither tasklists nor zonelists from two concurrent OOM kills overlap (tasks in separate memcgs bound to separate nodes) are OOM kills allowed to execute in parallel. The younger oom_sem is a read-write lock to serialize OOM killing against the PM code trying to disable the OOM killer altogether. However, the OOM killer is a fairly cold error path, there is really no reason to optimize for highly performant and concurrent OOM kills. And the oom_sem is just flat-out redundant. Replace both locking schemes with a single global mutex serializing OOM kills regardless of context. Change-Id: Ieb0b621bc3a391cc0a826a3ae53bf28ea4a8dbe5 Signed-off-by: Johannes Weiner Acked-by: Michal Hocko Acked-by: David Rientjes Cc: Tetsuo Handa Cc: Andrea Arcangeli Cc: Dave Chinner Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

oom, PM: make OOM detection in the freezer path raceless

2019-07-08T11:36:44+00:00

Commit 5695be142e20 ("OOM, PM: OOM killed task shouldn't escape PM suspend") has left a race window when OOM killer manages to note_oom_kill after freeze_processes checks the counter. The race window is quite small and really unlikely and partial solution deemed sufficient at the time of submission. Tejun wasn't happy about this partial solution though and insisted on a full solution. That requires the full OOM and freezer's task freezing exclusion, though. This is done by this patch which introduces oom_sem RW lock and turns oom_killer_disable() into a full OOM barrier. oom_killer_disabled check is moved from the allocation path to the OOM level and we take oom_sem for reading for both the check and the whole OOM invocation. oom_killer_disable() takes oom_sem for writing so it waits for all currently running OOM killer invocations. Then it disable all the further OOMs by setting oom_killer_disabled and checks for any oom victims. Victims are counted via mark_tsk_oom_victim resp. unmark_oom_victim. The last victim wakes up all waiters enqueued by oom_killer_disable(). Therefore this function acts as the full OOM barrier. The page fault path is covered now as well although it was assumed to be safe before. As per Tejun, "We used to have freezing points deep in file system code which may be reacheable from page fault." so it would be better and more robust to not rely on freezing points here. Same applies to the memcg OOM killer. out_of_memory tells the caller whether the OOM was allowed to trigger and the callers are supposed to handle the situation. The page allocation path simply fails the allocation same as before. The page fault path will retry the fault (more on that later) and Sysrq OOM trigger will simply complain to the log. Normally there wouldn't be any unfrozen user tasks after try_to_freeze_tasks so the function will not block. But if there was an OOM killer racing with try_to_freeze_tasks and the OOM victim didn't finish yet then we have to wait for it. This should complete in a finite time, though, because - the victim cannot loop in the page fault handler (it would die on the way out from the exception) - it cannot loop in the page allocator because all the further allocation would fail and __GFP_NOFAIL allocations are not acceptable at this stage - it shouldn't be blocked on any locks held by frozen tasks (try_to_freeze expects lockless context) and kernel threads and work queues are not frozen yet Change-Id: Ie72c2cfc39dad6420802b873053c739e804f956f Signed-off-by: Michal Hocko Suggested-by: Tejun Heo Cc: David Rientjes Cc: Johannes Weiner Cc: Oleg Nesterov Cc: Cong Wang Cc: "Rafael J. Wysocki" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm, oom: ensure memoryless node zonelist always includes zones

2019-05-02T16:39:03+00:00

With memoryless node support being worked on, it's possible that for optimizations that a node may not have a non-NULL zonelist. When CONFIG_NUMA is enabled and node 0 is memoryless, this means the zonelist for first_online_node may become NULL. The oom killer requires a zonelist that includes all memory zones for the sysrq trigger and pagefault out of memory handler. Ensure that a non-NULL zonelist is always passed to the oom killer. [akpm@linux-foundation.org: fix non-numa build] Signed-off-by: David Rientjes Cc: "Kirill A. Shutemov" Cc: Johannes Weiner Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Change-Id: Ic93a32abbf875a331244a0f95f2a0bcd0764360b

BACKPORT: tty: Use unbound workqueue for all input workers

2019-05-02T14:58:48+00:00

The commonly accepted wisdom that scheduling work on the same cpu that handled interrupt i/o benefits from cache-locality is only true if the cpu is idle (since bound kworkers are often the highest vruntime and thus the lowest priority). Measurements of scheduling via the unbound queue show lowered worst-case latency responses of up to 5x over bound workqueue, without increase in average latency or throughput. pty i/o test measurements show >3x (!) reduced total running time; tests previously taking ~8s now complete in <2.5s. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman Change-Id: I949ba6dfa56a802bba7c03e7ddbc2bde37b868ba

Replace with globally

2018-11-29T16:49:05+00:00

This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*' sed -i -e "s!$PATT!#include !" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro Signed-off-by: Linus Torvalds Signed-off-by: Moyster

format-security: move static strings to const

2017-12-05T17:06:11+00:00

While examining output from trial builds with -Wformat-security enabled, many strings were found that should be defined as "const", or as a char array instead of char pointer. This makes some static analysis easier, by producing fewer false positives. As these are all trivial changes, it seemed best to put them all in a single patch rather than chopping them up per maintainer. Link: http://lkml.kernel.org/r/20170405214711.GA5711@beast Signed-off-by: Kees Cook Acked-by: Jes Sorensen [runner.c] Cc: Tony Lindgren Cc: Russell King Cc: "Maciej W. Rozycki" Cc: Ralf Baechle Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Viresh Kumar Cc: Daniel Vetter Cc: Jani Nikula Cc: Sean Paul Cc: David Airlie Cc: Yisen Zhuang Cc: Salil Mehta Cc: Thomas Bogendoerfer Cc: Jiri Slaby Cc: Patrice Chotard Cc: "David S. Miller" Cc: James Hogan Cc: Paul Burton Cc: Matt Redfearn Cc: Paolo Bonzini Cc: Ingo Molnar Cc: Rasmus Villemoes Cc: Mugunthan V N Cc: Felipe Balbi Cc: Jarod Wilson Cc: Florian Westphal Cc: Antonio Quartulli Cc: Dmitry Torokhov Cc: Kejian Yan Cc: Daode Huang Cc: Qianqian Xie Cc: Philippe Reynes Cc: Colin Ian King Cc: Eric Dumazet Cc: Christian Gromm Cc: Andrey Shvetsov Cc: Jason Litzinger Cc: WANG Cong Signed-off-by: Andrew Morton

serial: efm32: Fix parity management in 'efm32_uart_console_get_options()'

2017-11-06T14:30:33+00:00

commit be40597a1bc173bf9dadccdf5388b956f620ae8f upstream. UARTn_FRAME_PARITY_ODD is 0x0300 UARTn_FRAME_PARITY_EVEN is 0x0200 So if the UART is configured for EVEN parity, it would be reported as ODD. Fix it by correctly testing if the 2 bits are set. Fixes: 3afbd89c9639 ("serial/efm32: add new driver") Signed-off-by: Christophe JAILLET Acked-by: Uwe Kleine-König Signed-off-by: Greg Kroah-Hartman Signed-off-by: Willy Tarreau

serial: ifx6x60: fix use-after-free on module unload

2017-11-06T14:19:04+00:00

commit 1e948479b3d63e3ac0ecca13cbf4921c7d17c168 upstream. Make sure to deregister the SPI driver before releasing the tty driver to avoid use-after-free in the SPI remove callback where the tty devices are deregistered. Fixes: 72d4724ea54c ("serial: ifx6x60: Add modem power off function in the platform reboot process") Cc: stable # 3.8 Cc: Jun Chen Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman Signed-off-by: Willy Tarreau

vt: fix unchecked __put_user() in tioclinux ioctls

2017-08-30T23:38:20+00:00

Only read access is checked before this call. Actually, at the moment this is not an issue, as every in-tree arch does the same manual checks for VERIFY_READ vs VERIFY_WRITE, relying on the MMU to tell them apart, but this wasn't the case in the past and may happen again on some odd arch in the future. If anyone cares about 3.7 and earlier, this is a security hole (untested) on real 80386 CPUs. Signed-off-by: Adam Borowski CC: stable@vger.kernel.org # v3.7- Signed-off-by: Greg Kroah-Hartman