- 04 Oct, 2017 40 commits
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Stafford Horne authored
Currently running checkpatch on a directory with a cover-letter.patch file reports the following error: ----------------------------------------- patches/smp-v2/v2-0000-cover-letter.patch ----------------------------------------- ERROR: Does not appear to be a unified-diff format patch The logic to suppress the unified-diff check for cover letters is there but is checking $file instead of $filename. Fix the variable to use the correct one. Link: http://lkml.kernel.org/r/20170909090406.31523-1-shorne@gmail.comSigned-off-by:
Stafford Horne <shorne@gmail.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>
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Sudip Mukherjee authored
The allmodconfig build of m32r is failing with the error: lib/mpi/mpih-div.o: In function 'mpihelp_divrem': mpih-div.c:(.text+0x40): undefined reference to 'abort' mpih-div.c:(.text+0x40): relocation truncated to fit: R_M32R_26_PCREL_RELA against undefined symbol 'abort' The function 'abort' was never defined for the m32r architecture. Create 'abort' as is done in other arch like 'arm' and 'unicore32'. Link: http://lkml.kernel.org/r/1506727220-6108-1-git-send-email-sudip.mukherjee@codethink.co.ukSigned-off-by:
Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by:
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Sergey Senozhatsky authored
printk_ratelimit() invokes ___ratelimit() which may invoke a normal printk() (pr_warn() in this particular case) to warn about suppressed output. Given that printk_ratelimit() may be called from anywhere, that pr_warn() is dangerous - it may end up deadlocking the system. Fix ___ratelimit() by using deferred printk(). Sasha reported the following lockdep error: : Unregister pv shared memory for cpu 8 : select_fallback_rq: 3 callbacks suppressed : process 8583 (trinity-c78) no longer affine to cpu8 : : ====================================================== : WARNING: possible circular locking dependency detected : 4.14.0-rc2-next-20170927+ #252 Not tainted : ------------------------------------------------------ : migration/8/62 is trying to acquire lock: : (&port_lock_key){-.-.}, at: serial8250_console_write() : : but task is already holding lock: : (&rq->lock){-.-.}, at: sched_cpu_dying() : : which lock already depends on the new lock. : : : the existing dependency chain (in reverse order) is: : : -> #3 (&rq->lock){-.-.}: : __lock_acquire() : lock_acquire() : _raw_spin_lock() : task_fork_fair() : sched_fork() : copy_process.part.31() : _do_fork() : kernel_thread() : rest_init() : start_kernel() : x86_64_start_reservations() : x86_64_start_kernel() : verify_cpu() : : -> #2 (&p->pi_lock){-.-.}: : __lock_acquire() : lock_acquire() : _raw_spin_lock_irqsave() : try_to_wake_up() : default_wake_function() : woken_wake_function() : __wake_up_common() : __wake_up_common_lock() : __wake_up() : tty_wakeup() : tty_port_default_wakeup() : tty_port_tty_wakeup() : uart_write_wakeup() : serial8250_tx_chars() : serial8250_handle_irq.part.25() : serial8250_default_handle_irq() : serial8250_interrupt() : __handle_irq_event_percpu() : handle_irq_event_percpu() : handle_irq_event() : handle_level_irq() : handle_irq() : do_IRQ() : ret_from_intr() : native_safe_halt() : default_idle() : arch_cpu_idle() : default_idle_call() : do_idle() : cpu_startup_entry() : rest_init() : start_kernel() : x86_64_start_reservations() : x86_64_start_kernel() : verify_cpu() : : -> #1 (&tty->write_wait){-.-.}: : __lock_acquire() : lock_acquire() : _raw_spin_lock_irqsave() : __wake_up_common_lock() : __wake_up() : tty_wakeup() : tty_port_default_wakeup() : tty_port_tty_wakeup() : uart_write_wakeup() : serial8250_tx_chars() : serial8250_handle_irq.part.25() : serial8250_default_handle_irq() : serial8250_interrupt() : __handle_irq_event_percpu() : handle_irq_event_percpu() : handle_irq_event() : handle_level_irq() : handle_irq() : do_IRQ() : ret_from_intr() : native_safe_halt() : default_idle() : arch_cpu_idle() : default_idle_call() : do_idle() : cpu_startup_entry() : rest_init() : start_kernel() : x86_64_start_reservations() : x86_64_start_kernel() : verify_cpu() : : -> #0 (&port_lock_key){-.-.}: : check_prev_add() : __lock_acquire() : lock_acquire() : _raw_spin_lock_irqsave() : serial8250_console_write() : univ8250_console_write() : console_unlock() : vprintk_emit() : vprintk_default() : vprintk_func() : printk() : ___ratelimit() : __printk_ratelimit() : select_fallback_rq() : sched_cpu_dying() : cpuhp_invoke_callback() : take_cpu_down() : multi_cpu_stop() : cpu_stopper_thread() : smpboot_thread_fn() : kthread() : ret_from_fork() : : other info that might help us debug this: : : Chain exists of: : &port_lock_key --> &p->pi_lock --> &rq->lock : : Possible unsafe locking scenario: : : CPU0 CPU1 : ---- ---- : lock(&rq->lock); : lock(&p->pi_lock); : lock(&rq->lock); : lock(&port_lock_key); : : *** DEADLOCK *** : : 4 locks held by migration/8/62: : #0: (&p->pi_lock){-.-.}, at: sched_cpu_dying() : #1: (&rq->lock){-.-.}, at: sched_cpu_dying() : #2: (printk_ratelimit_state.lock){....}, at: ___ratelimit() : #3: (console_lock){+.+.}, at: vprintk_emit() : : stack backtrace: : CPU: 8 PID: 62 Comm: migration/8 Not tainted 4.14.0-rc2-next-20170927+ #252 : Call Trace: : dump_stack() : print_circular_bug() : check_prev_add() : ? add_lock_to_list.isra.26() : ? check_usage() : ? kvm_clock_read() : ? kvm_sched_clock_read() : ? sched_clock() : ? check_preemption_disabled() : __lock_acquire() : ? __lock_acquire() : ? add_lock_to_list.isra.26() : ? debug_check_no_locks_freed() : ? memcpy() : lock_acquire() : ? serial8250_console_write() : _raw_spin_lock_irqsave() : ? serial8250_console_write() : serial8250_console_write() : ? serial8250_start_tx() : ? lock_acquire() : ? memcpy() : univ8250_console_write() : console_unlock() : ? __down_trylock_console_sem() : vprintk_emit() : vprintk_default() : vprintk_func() : printk() : ? show_regs_print_info() : ? lock_acquire() : ___ratelimit() : __printk_ratelimit() : select_fallback_rq() : sched_cpu_dying() : ? sched_cpu_starting() : ? rcutree_dying_cpu() : ? sched_cpu_starting() : cpuhp_invoke_callback() : ? cpu_disable_common() : take_cpu_down() : ? trace_hardirqs_off_caller() : ? cpuhp_invoke_callback() : multi_cpu_stop() : ? __this_cpu_preempt_check() : ? cpu_stop_queue_work() : cpu_stopper_thread() : ? cpu_stop_create() : smpboot_thread_fn() : ? sort_range() : ? schedule() : ? __kthread_parkme() : kthread() : ? sort_range() : ? kthread_create_on_node() : ret_from_fork() : process 9121 (trinity-c78) no longer affine to cpu8 : smpboot: CPU 8 is now offline Link: http://lkml.kernel.org/r/20170928120405.18273-1-sergey.senozhatsky@gmail.com Fixes: 6b1d174b ("ratelimit: extend to print suppressed messages on release") Signed-off-by:Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by:
Sasha Levin <levinsasha928@gmail.com> Reviewed-by:
Petr Mladek <pmladek@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Borislav Petkov <bp@suse.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: <stable@vger.kernel.org> Signed-off-by:
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Jean Delvare authored
Align the parameters passed to STANDARD_PARAM_DEF for clarity. Link: http://lkml.kernel.org/r/20170928162728.756143cc@endymionSigned-off-by:
Jean Delvare <jdelvare@suse.de> Suggested-by:
Ingo Molnar <mingo@kernel.org> Acked-by:
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Jean Delvare authored
Function param_attr_show could overflow the buffer it is operating on. The buffer size is PAGE_SIZE, and the string returned by attribute->param->ops->get is generated by scnprintf(buffer, PAGE_SIZE, ...) so it could be PAGE_SIZE - 1 long, with the terminating '\0' at the very end of the buffer. Calling strcat(..., "\n") on this isn't safe, as the '\0' will be replaced by '\n' (OK) and then another '\0' will be added past the end of the buffer (not OK.) Simply add the trailing '\n' when writing the attribute contents to the buffer originally. This is safe, and also faster. Credits to Teradata for discovering this issue. Link: http://lkml.kernel.org/r/20170928162602.60c379c7@endymionSigned-off-by:
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Jean Delvare authored
The length parameter of strlcpy() is supposed to reflect the size of the target buffer, not of the source string. Harmless in this case as the buffer is PAGE_SIZE long and the source string is always much shorter than this, but conceptually wrong, so let's fix it. Link: http://lkml.kernel.org/r/20170928162515.24846b4f@endymionSigned-off-by:
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YASUAKI ISHIMATSU authored
find_{smallest|biggest}_section_pfn()s find the smallest/biggest section and return the pfn of the section. But the functions are defined as int. So the functions always return 0x00000000 - 0xffffffff. It means if memory address is over 16TB, the functions does not work correctly. To handle 64 bit value, the patch defines find_{smallest|biggest}_section_pfn() as unsigned long. Fixes: 815121d2 ("memory_hotplug: clear zone when removing the memory") Link: http://lkml.kernel.org/r/d9d5593a-d0a4-c4be-ab08-493df59a85c6@gmail.comSigned-off-by:Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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YASUAKI ISHIMATSU authored
pfn_to_section_nr() and section_nr_to_pfn() are defined as macro. pfn_to_section_nr() has no issue even if it is defined as macro. But section_nr_to_pfn() has overflow issue if sec is defined as int. section_nr_to_pfn() just shifts sec by PFN_SECTION_SHIFT. If sec is defined as unsigned long, section_nr_to_pfn() returns pfn as 64 bit value. But if sec is defined as int, section_nr_to_pfn() returns pfn as 32 bit value. __remove_section() calculates start_pfn using section_nr_to_pfn() and scn_nr defined as int. So if hot-removed memory address is over 16TB, overflow issue occurs and section_nr_to_pfn() does not calculate correct pfn. To make callers use proper arg, the patch changes the macros to inline functions. Fixes: 815121d2 ("memory_hotplug: clear zone when removing the memory") Link: http://lkml.kernel.org/r/e643a387-e573-6bbf-d418-c60c8ee3d15e@gmail.comSigned-off-by:
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Cyrill Gorcunov authored
The else branch been left over and escaped the source code refresh. Not a problem but better clean it up. Fixes: 0791e364 ("kcmp: add KCMP_EPOLL_TFD mode to compare epoll target files") Link: http://lkml.kernel.org/r/20170917165838.GA1887@uranus.lanReported-by:
Eugene Syromiatnikov <esyr@redhat.com> Signed-off-by:
Cyrill Gorcunov <gorcunov@openvz.org> Acked-by:
Andrei Vagin <avagin@virtuozzo.com> Cc: Pavel Emelyanov <xemul@virtuozzo.com> Signed-off-by:
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Michal Hocko authored
devm_memremap_pages is initializing struct pages in for_each_device_pfn and that can take quite some time. We have even seen a soft lockup triggering on a non preemptive kernel NMI watchdog: BUG: soft lockup - CPU#61 stuck for 22s! [kworker/u641:11:1808] [...] RIP: 0010:[<ffffffff8118b6b7>] [<ffffffff8118b6b7>] devm_memremap_pages+0x327/0x430 [...] Call Trace: pmem_attach_disk+0x2fd/0x3f0 [nd_pmem] nvdimm_bus_probe+0x64/0x110 [libnvdimm] driver_probe_device+0x1f7/0x420 bus_for_each_drv+0x52/0x80 __device_attach+0xb0/0x130 bus_probe_device+0x87/0xa0 device_add+0x3fc/0x5f0 nd_async_device_register+0xe/0x40 [libnvdimm] async_run_entry_fn+0x43/0x150 process_one_work+0x14e/0x410 worker_thread+0x116/0x490 kthread+0xc7/0xe0 ret_from_fork+0x3f/0x70 fix this by adding cond_resched every 1024 pages. Link: http://lkml.kernel.org/r/20170918121410.24466-4-mhocko@kernel.orgSigned-off-by:Johannes Thumshirn <jthumshirn@suse.de> Tested-by:
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Michal Hocko authored
memmap_init_zone gets a pfn range to initialize and it can be really large resulting in a soft lockup on non-preemptible kernels NMI watchdog: BUG: soft lockup - CPU#31 stuck for 23s! [kworker/u642:5:1720] [...] task: ffff88ecd7e902c0 ti: ffff88eca4e50000 task.ti: ffff88eca4e50000 RIP: move_pfn_range_to_zone+0x185/0x1d0 [...] Call Trace: devm_memremap_pages+0x2c7/0x430 pmem_attach_disk+0x2fd/0x3f0 [nd_pmem] nvdimm_bus_probe+0x64/0x110 [libnvdimm] driver_probe_device+0x1f7/0x420 bus_for_each_drv+0x52/0x80 __device_attach+0xb0/0x130 bus_probe_device+0x87/0xa0 device_add+0x3fc/0x5f0 nd_async_device_register+0xe/0x40 [libnvdimm] async_run_entry_fn+0x43/0x150 process_one_work+0x14e/0x410 worker_thread+0x116/0x490 kthread+0xc7/0xe0 ret_from_fork+0x3f/0x70 Fix this by adding a scheduling point once per page block. Link: http://lkml.kernel.org/r/20170918121410.24466-3-mhocko@kernel.orgSigned-off-by: -
Michal Hocko authored
Patch series "mm, memory_hotplug: fix few soft lockups in memory hotadd". Johannes has noticed few soft lockups when adding a large nvdimm device. All of them were caused by a long loop without any explicit cond_resched which is a problem for !PREEMPT kernels. The fix is quite straightforward. Just make sure that cond_resched gets called from time to time. This patch (of 3): __add_pages gets a pfn range to add and there is no upper bound for a single call. This is usually a memory block aligned size for the regular memory hotplug - smaller sizes are usual for memory balloning drivers, or the whole NUMA node for physical memory online. There is no explicit scheduling point in that code path though. This can lead to long latencies while __add_pages is executed and we have even seen a soft lockup report during nvdimm initialization with !PREEMPT kernel NMI watchdog: BUG: soft lockup - CPU#11 stuck for 23s! [kworker/u641:3:832] [...] Workqueue: events_unbound async_run_entry_fn task: ffff881809270f40 ti: ffff881809274000 task.ti: ffff881809274000 RIP: _raw_spin_unlock_irqrestore+0x11/0x20 RSP: 0018:ffff881809277b10 EFLAGS: 00000286 [...] Call Trace: sparse_add_one_section+0x13d/0x18e __add_pages+0x10a/0x1d0 arch_add_memory+0x4a/0xc0 devm_memremap_pages+0x29d/0x430 pmem_attach_disk+0x2fd/0x3f0 [nd_pmem] nvdimm_bus_probe+0x64/0x110 [libnvdimm] driver_probe_device+0x1f7/0x420 bus_for_each_drv+0x52/0x80 __device_attach+0xb0/0x130 bus_probe_device+0x87/0xa0 device_add+0x3fc/0x5f0 nd_async_device_register+0xe/0x40 [libnvdimm] async_run_entry_fn+0x43/0x150 process_one_work+0x14e/0x410 worker_thread+0x116/0x490 kthread+0xc7/0xe0 ret_from_fork+0x3f/0x70 DWARF2 unwinder stuck at ret_from_fork+0x3f/0x70 Fix this by adding cond_resched once per each memory section in the given pfn range. Each section is constant amount of work which itself is not too expensive but many of them will just add up. Link: http://lkml.kernel.org/r/20170918121410.24466-2-mhocko@kernel.orgSigned-off-by: -
Eric Biggers authored
idr_replace() returns the old value on success, not 0. Link: http://lkml.kernel.org/r/20170918162642.37511-1-ebiggers3@gmail.comSigned-off-by:
Eric Biggers <ebiggers@google.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by:
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Johannes Weiner authored
For quick per-memcg indexing, slab caches and list_lru structures maintain linear arrays of descriptors. As the number of concurrent memory cgroups in the system goes up, this requires large contiguous allocations (8k cgroups = order-5, 16k cgroups = order-6 etc.) for every existing slab cache and list_lru, which can easily fail on loaded systems. E.g.: mkdir: page allocation failure: order:5, mode:0x14040c0(GFP_KERNEL|__GFP_COMP), nodemask=(null) CPU: 1 PID: 6399 Comm: mkdir Not tainted 4.13.0-mm1-00065-g720bbe532b7c-dirty #481 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-20170228_101828-anatol 04/01/2014 Call Trace: ? __alloc_pages_direct_compact+0x4c/0x110 __alloc_pages_nodemask+0xf50/0x1430 alloc_pages_current+0x60/0xc0 kmalloc_order_trace+0x29/0x1b0 __kmalloc+0x1f4/0x320 memcg_update_all_list_lrus+0xca/0x2e0 mem_cgroup_css_alloc+0x612/0x670 cgroup_apply_control_enable+0x19e/0x360 cgroup_mkdir+0x322/0x490 kernfs_iop_mkdir+0x55/0x80 vfs_mkdir+0xd0/0x120 SyS_mkdirat+0x6c/0xe0 SyS_mkdir+0x14/0x20 entry_SYSCALL_64_fastpath+0x18/0xad Mem-Info: active_anon:2965 inactive_anon:19 isolated_anon:0 active_file:100270 inactive_file:98846 isolated_file:0 unevictable:0 dirty:0 writeback:0 unstable:0 slab_reclaimable:7328 slab_unreclaimable:16402 mapped:771 shmem:52 pagetables:278 bounce:0 free:13718 free_pcp:0 free_cma:0 This output is from an artificial reproducer, but we have repeatedly observed order-7 failures in production in the Facebook fleet. These systems become useless as they cannot run more jobs, even though there is plenty of memory to allocate 128 individual pages. Use kvmalloc and kvzalloc to fall back to vmalloc space if these arrays prove too large for allocating them physically contiguous. Link: http://lkml.kernel.org/r/20170918184919.20644-1-hannes@cmpxchg.orgSigned-off-by:
Johannes Weiner <hannes@cmpxchg.org> Reviewed-by:
Josef Bacik <jbacik@fb.com> Acked-by:
Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by:
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Luis R. Rodriguez authored
do_proc_douintvec_conv() has two UINT_MAX checks, we can remove one. This has no functional changes other than fixing a compiler warning: kernel/sysctl.c:2190]: (warning) Identical condition '*lvalp>UINT_MAX', second condition is always false Fixes: 4f2fec00 ("sysctl: simplify unsigned int support") Link: http://lkml.kernel.org/r/20170919072918.12066-1-mcgrof@kernel.orgSigned-off-by:
Luis R. Rodriguez <mcgrof@kernel.org> Reported-by:
David Binderman <dcb314@hotmail.com> Acked-by:
Kees Cook <keescook@chromium.org> Signed-off-by:
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Masahiro Yamada authored
I do not see anything that restricts this macro to 32 bit width. Link: http://lkml.kernel.org/r/1505921975-23379-1-git-send-email-yamada.masahiro@socionext.comSigned-off-by:
Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by:
Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by:
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Colin Ian King authored
Don't populate the read-only arrays dec32table and dec64table on the stack, instead make them both static const. Makes the object code smaller by over 10K bytes: Before: text data bss dec hex filename 31500 0 0 31500 7b0c lib/lz4/lz4_decompress.o After: text data bss dec hex filename 20237 176 0 20413 4fbd lib/lz4/lz4_decompress.o (gcc version 7.2.0 x86_64) Link: http://lkml.kernel.org/r/20170921221939.20820-1-colin.king@canonical.comSigned-off-by:Colin Ian King <colin.king@canonical.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Sven Schmidt <4sschmid@informatik.uni-hamburg.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Joe Perches <joe@perches.com> Signed-off-by:
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Oleg Nesterov authored
After the previous change "fmt" can't go away, we can kill iname/iname_addr and use fmt->interpreter. Link: http://lkml.kernel.org/r/20170922143653.GA17232@redhat.comSigned-off-by:
Oleg Nesterov <oleg@redhat.com> Acked-by:
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Oleg Nesterov authored
load_misc_binary() makes a local copy of fmt->interpreter under entries_lock to avoid the race with kill_node() but this is not enough; the whole Node can be freed after we drop entries_lock, not only the ->interpreter string. Add dget/dput(fmt->dentry) to ensure bm_evict_inode() can't destroy/free this Node. Link: http://lkml.kernel.org/r/20170922143650.GA17227@redhat.comSigned-off-by:
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Oleg Nesterov authored
If MISC_FMT_OPEN_FILE flag is set e->interp_file must be valid or we have a bug which should not be silently ignored. Link: http://lkml.kernel.org/r/20170922143647.GA17222@redhat.comSigned-off-by:
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Oleg Nesterov authored
To ensure that load_misc_binary() can't use the partially destroyed Node, see also the next patch. The current logic looks wrong in any case, once we close interp_file it doesn't make any sense to delay kfree(inode->i_private), this Node is no longer valid. Even if the MISC_FMT_OPEN_FILE/interp_file checks were not racy (they are), load_misc_binary() should not try to reopen ->interpreter if MISC_FMT_OPEN_FILE is set but ->interp_file is NULL. And I can't understand why do we use filp_close(), not fput(). Link: http://lkml.kernel.org/r/20170922143644.GA17216@redhat.comSigned-off-by:
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Oleg Nesterov authored
kill_node() nullifies/checks Node->dentry to avoid double free. This complicates the next changes and this is very confusing: - we do not need to check dentry != NULL under entries_lock, kill_node() is always called under inode_lock(d_inode(root)) and we rely on this inode_lock() anyway, without this lock the MISC_FMT_OPEN_FILE cleanup could race with itself. - if kill_inode() was already called and ->dentry == NULL we should not even try to close e->interp_file. We can change bm_entry_write() to simply check !list_empty(list) before kill_node. Again, we rely on inode_lock(), in particular it saves us from the race with bm_status_write(), another caller of kill_node(). Link: http://lkml.kernel.org/r/20170922143641.GA17210@redhat.comSigned-off-by:
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Oleg Nesterov authored
Patch series "exec: binfmt_misc: fix use-after-free, kill iname[BINPRM_BUF_SIZE]". It looks like this code was always wrong, then commit 948b701a ("binfmt_misc: add persistent opened binary handler for containers") added more problems. This patch (of 6): load_script() can simply use i_name instead, it points into bprm->buf[] and nobody can change this memory until we call prepare_binprm(). The only complication is that we need to also change the signature of bprm_change_interp() but this change looks good too. While at it, do whitespace/style cleanups. NOTE: the real motivation for this change is that people want to increase BINPRM_BUF_SIZE, we need to change load_misc_binary() too but this looks more complicated because afaics it is very buggy. Link: http://lkml.kernel.org/r/20170918163446.GA26793@redhat.comSigned-off-by:
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Andrea Arcangeli authored
When reading the event from the uffd, we put it on a temporary fork_event list to detect if we can still access it after releasing and retaking the event_wqh.lock. If fork aborts and removes the event from the fork_event all is fine as long as we're still in the userfault read context and fork_event head is still alive. We've to put the event allocated in the fork kernel stack, back from fork_event list-head to the event_wqh head, before returning from userfaultfd_ctx_read, because the fork_event head lifetime is limited to the userfaultfd_ctx_read stack lifetime. Forgetting to move the event back to its event_wqh place then results in __remove_wait_queue(&ctx->event_wqh, &ewq->wq); in userfaultfd_event_wait_completion to remove it from a head that has been already freed from the reader stack. This could only happen if resolve_userfault_fork failed (for example if there are no file descriptors available to allocate the fork uffd). If it succeeded it was put back correctly. Furthermore, after find_userfault_evt receives a fork event, the forked userfault context in fork_nctx and uwq->msg.arg.reserved.reserved1 can be released by the fork thread as soon as the event_wqh.lock is released. Taking a reference on the fork_nctx before dropping the lock prevents an use after free in resolve_userfault_fork(). If the fork side aborted and it already released everything, we still try to succeed resolve_userfault_fork(), if possible. Fixes: 893e26e6 ("userfaultfd: non-cooperative: Add fork() event") Link: http://lkml.kernel.org/r/20170920180413.26713-1-aarcange@redhat.comSigned-off-by:
Andrea Arcangeli <aarcange@redhat.com> Reported-by:
Mark Rutland <mark.rutland@arm.com> Tested-by:
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Reza Arbab authored
With device public pages at the end of my memory space, I'm getting output from _vm_normal_page(): BUG: Bad page map in process migrate_pages pte:c0800001ffff0d06 pmd:f95d3000 addr:00007fff89330000 vm_flags:00100073 anon_vma:c0000000fa899320 mapping: (null) index:7fff8933 file: (null) fault: (null) mmap: (null) readpage: (null) CPU: 0 PID: 13963 Comm: migrate_pages Tainted: P B OE 4.14.0-rc1-wip #155 Call Trace: dump_stack+0xb0/0xf4 (unreliable) print_bad_pte+0x28c/0x340 _vm_normal_page+0xc0/0x140 zap_pte_range+0x664/0xc10 unmap_page_range+0x318/0x670 unmap_vmas+0x74/0xe0 exit_mmap+0xe8/0x1f0 mmput+0xac/0x1f0 do_exit+0x348/0xcd0 do_group_exit+0x5c/0xf0 SyS_exit_group+0x1c/0x20 system_call+0x58/0x6c The pfn causing this is the very last one. Correct the bounds check accordingly. Fixes: df6ad698 ("mm/device-public-memory: device memory cache coherent with CPU") Link: http://lkml.kernel.org/r/1506092178-20351-1-git-send-email-arbab@linux.vnet.ibm.comSigned-off-by:Reza Arbab <arbab@linux.vnet.ibm.com> Reviewed-by:
Jérôme Glisse <jglisse@redhat.com> Reviewed-by:
Balbir Singh <bsingharora@gmail.com> Signed-off-by:
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Shaohua Li authored
MADV_FREE clears pte dirty bit and then marks the page lazyfree (clear SwapBacked). There is no lock to prevent the page is added to swap cache between these two steps by page reclaim. If page reclaim finds such page, it will simply add the page to swap cache without pageout the page to swap because the page is marked as clean. Next time, page fault will read data from the swap slot which doesn't have the original data, so we have a data corruption. To fix issue, we mark the page dirty and pageout the page. However, we shouldn't dirty all pages which is clean and in swap cache. swapin page is swap cache and clean too. So we only dirty page which is added into swap cache in page reclaim, which shouldn't be swapin page. As Minchan suggested, simply dirty the page in add_to_swap can do the job. Fixes: 802a3a92 ("mm: reclaim MADV_FREE pages") Link: http://lkml.kernel.org/r/08c84256b007bf3f63c91d94383bd9eb6fee2daa.1506446061.git.shli@fb.comSigned-off-by:
Shaohua Li <shli@fb.com> Reported-by:
Artem Savkov <asavkov@redhat.com> Acked-by:
Minchan Kim <minchan@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Hillf Danton <hdanton@sina.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: <stable@vger.kernel.org> [4.12+] Signed-off-by:
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Shaohua Li authored
MADV_FREE clears pte dirty bit and then marks the page lazyfree (clear SwapBacked). There is no lock to prevent the page is added to swap cache between these two steps by page reclaim. Page reclaim could add the page to swap cache and unmap the page. After page reclaim, the page is added back to lru. At that time, we probably start draining per-cpu pagevec and mark the page lazyfree. So the page could be in a state with SwapBacked cleared and PG_swapcache set. Next time there is a refault in the virtual address, do_swap_page can find the page from swap cache but the page has PageSwapCache false because SwapBacked isn't set, so do_swap_page will bail out and do nothing. The task will keep running into fault handler. Fixes: 802a3a92 ("mm: reclaim MADV_FREE pages") Link: http://lkml.kernel.org/r/6537ef3814398c0073630b03f176263bc81f0902.1506446061.git.shli@fb.comSigned-off-by:
Rik van Riel <riel@redhat.com> Acked-by:
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Jeff Layton authored
Eryu noticed that he could sometimes get a leftover error reported when it shouldn't be on fsync with ext2 and non-journalled ext4. The problem is that writeback_single_inode still uses filemap_fdatawait. That picks up a previously set AS_EIO flag, which would ordinarily have been cleared before. Since we're mostly using this function as a replacement for filemap_check_errors, have filemap_check_and_advance_wb_err clear AS_EIO and AS_ENOSPC when reporting an error. That should allow the new function to better emulate the behavior of the old with respect to these flags. Link: http://lkml.kernel.org/r/20170922133331.28812-1-jlayton@kernel.orgSigned-off-by:
Jeff Layton <jlayton@redhat.com> Reported-by:
Eryu Guan <eguan@redhat.com> Reviewed-by:
Jan Kara <jack@suse.cz> Signed-off-by:
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Sudip Mukherjee authored
The build of m32r allmodconfig is giving lots of build warnings about: include/linux/byteorder/big_endian.h:7:2: warning: #warning inconsistent configuration, needs CONFIG_CPU_BIG_ENDIAN [-Wcpp] #warning inconsistent configuration, needs CONFIG_CPU_BIG_ENDIAN Define CPU_BIG_ENDIAN like the way CPU_LITTLE_ENDIAN is defined. Link: http://lkml.kernel.org/r/1505678083-10320-1-git-send-email-sudipm.mukherjee@gmail.comSigned-off-by:
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Minchan Kim authored
In testing I found handle passed to zs_map_object in __zram_bvec_read is NULL so eh kernel goes oops in pin_object(). The reason is there is no routine to check the slot's freeing after getting the slot's lock. This patch fixes it. [minchan@kernel.org: v2] Link: http://lkml.kernel.org/r/1505887347-10881-1-git-send-email-minchan@kernel.org Link: http://lkml.kernel.org/r/1505788488-26723-1-git-send-email-minchan@kernel.org Fixes: 1f7319c7 ("zram: partial IO refactoring") Signed-off-by:
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Christophe Leroy authored
On powerpc, RODATA_TEST fails with message the following messages: Freeing unused kernel memory: 528K rodata_test: test data was not read only This is because GCC allocates it to .data section: c0695034 g O .data 00000004 rodata_test_data Since commit 056b9d8a ("mm: remove rodata_test_data export, add pr_fmt"), rodata_test_data is used only inside rodata_test.c By declaring it static, it gets properly allocated into .rodata section instead of .data: c04df710 l O .rodata 00000004 rodata_test_data Fixes: 056b9d8a ("mm: remove rodata_test_data export, add pr_fmt") Link: http://lkml.kernel.org/r/20170921093729.1080368AC1@po15668-vm-win7.idsi0.si.c-s.frSigned-off-by:
Christophe Leroy <christophe.leroy@c-s.fr> Cc: Kees Cook <keescook@chromium.org> Cc: Jinbum Park <jinb.park7@gmail.com> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: David Laight <David.Laight@ACULAB.COM> Cc: <stable@vger.kernel.org> Signed-off-by:
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Ioan Nicu authored
Locking of config and doorbell operations should be done only if the underlying hardware requires it. This patch removes the global spinlocks from the rapidio subsystem and moves them to the mport drivers (fsl_rio and tsi721), only to the necessary places. For example, local config space read and write operations (lcread/lcwrite) are atomic in all existing drivers, so there should be no need for locking, while the cread/cwrite operations which generate maintenance transactions need to be synchronized with a lock. Later, each driver could chose to use a per-port lock instead of a global one, or even more granular locking. Link: http://lkml.kernel.org/r/20170824113023.GD50104@nokia.comSigned-off-by:
Ioan Nicu <ioan.nicu.ext@nokia.com> Signed-off-by:
Frank Kunz <frank.kunz@nokia.com> Acked-by:
Alexandre Bounine <alexandre.bounine@idt.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by:
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Arnd Bergmann authored
The function is called from __meminit context and calls other __meminit functions but isn't it self mark as such today: WARNING: vmlinux.o(.text.unlikely+0x4516): Section mismatch in reference from the function init_reserved_page() to the function .meminit.text:early_pfn_to_nid() The function init_reserved_page() references the function __meminit early_pfn_to_nid(). This is often because init_reserved_page lacks a __meminit annotation or the annotation of early_pfn_to_nid is wrong. On most compilers, we don't notice this because the function gets inlined all the time. Adding __meminit here fixes the harmless warning for the old versions and is generally the correct annotation. Link: http://lkml.kernel.org/r/20170915193149.901180-1-arnd@arndb.de Fixes: 7e18adb4 ("mm: meminit: initialise remaining struct pages in parallel with kswapd") Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Acked-by:
Mel Gorman <mgorman@techsingularity.net> Signed-off-by:
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Vitaly Wool authored
Fix the situation when clear_bit() is called for page->private before the page pointer is actually assigned. While at it, remove work_busy() check because it is costly and does not give 100% guarantee anyway. Signed-off-by:
Vitaly Wool <vitalywool@gmail.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: <Oleksiy.Avramchenko@sony.com> Signed-off-by:
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Davidlohr Bueso authored
Andrea brought to my attention that the L->{L,S} guarantees are completely bogus for this case. I was looking at the diagram, from the offending commit, when that _is_ the race, we had the load reordered already. What we need is at least S->L semantics, thus simply use wq_has_sleeper() to serialize the call for good. Link: http://lkml.kernel.org/r/20170914175313.GB811@linux-80c1.suse Fixes: 46acef04 (mm,compaction: serialize waitqueue_active() checks) Signed-off-by:Davidlohr Bueso <dbueso@suse.de> Reported-by:
Andrea Parri <parri.andrea@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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Sherry Yang authored
Drop the global lru lock in isolate callback before calling zap_page_range which calls cond_resched, and re-acquire the global lru lock before returning. Also change return code to LRU_REMOVED_RETRY. Use mmput_async when fail to acquire mmap sem in an atomic context. Fix "BUG: sleeping function called from invalid context" errors when CONFIG_DEBUG_ATOMIC_SLEEP is enabled. Also restore mmput_async, which was initially introduced in commit ec8d7c14 ("mm, oom_reaper: do not mmput synchronously from the oom reaper context"), and was removed in commit 21292580 ("mm: oom: let oom_reap_task and exit_mmap run concurrently"). Link: http://lkml.kernel.org/r/20170914182231.90908-1-sherryy@android.com Fixes: f2517eb7 ("android: binder: Add global lru shrinker to binder") Signed-off-by:
Sherry Yang <sherryy@android.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reported-by:
Kyle Yan <kyan@codeaurora.org> Acked-by:
Arve Hjønnevåg <arve@android.com> Acked-by:
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Jérôme Glisse authored
Fix for 4.14, zone device page always have an elevated refcount of one and thus page count sanity check in uncharge_page() is inappropriate for them. [mhocko@suse.com: nano-optimize VM_BUG_ON in uncharge_page] Link: http://lkml.kernel.org/r/20170914190011.5217-1-jglisse@redhat.comSigned-off-by:
Evgeny Baskakov <ebaskakov@nvidia.com> Acked-by:
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Michal Hocko authored
The following lockdep splat has been noticed during LTP testing ====================================================== WARNING: possible circular locking dependency detected 4.13.0-rc3-next-20170807 #12 Not tainted ------------------------------------------------------ a.out/4771 is trying to acquire lock: (cpu_hotplug_lock.rw_sem){++++++}, at: [<ffffffff812b4668>] drain_all_stock.part.35+0x18/0x140 but task is already holding lock: (&mm->mmap_sem){++++++}, at: [<ffffffff8106eb35>] __do_page_fault+0x175/0x530 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&mm->mmap_sem){++++++}: lock_acquire+0xc9/0x230 __might_fault+0x70/0xa0 _copy_to_user+0x23/0x70 filldir+0xa7/0x110 xfs_dir2_sf_getdents.isra.10+0x20c/0x2c0 [xfs] xfs_readdir+0x1fa/0x2c0 [xfs] xfs_file_readdir+0x30/0x40 [xfs] iterate_dir+0x17a/0x1a0 SyS_getdents+0xb0/0x160 entry_SYSCALL_64_fastpath+0x1f/0xbe -> #2 (&type->i_mutex_dir_key#3){++++++}: lock_acquire+0xc9/0x230 down_read+0x51/0xb0 lookup_slow+0xde/0x210 walk_component+0x160/0x250 link_path_walk+0x1a6/0x610 path_openat+0xe4/0xd50 do_filp_open+0x91/0x100 file_open_name+0xf5/0x130 filp_open+0x33/0x50 kernel_read_file_from_path+0x39/0x80 _request_firmware+0x39f/0x880 request_firmware_direct+0x37/0x50 request_microcode_fw+0x64/0xe0 reload_store+0xf7/0x180 dev_attr_store+0x18/0x30 sysfs_kf_write+0x44/0x60 kernfs_fop_write+0x113/0x1a0 __vfs_write+0x37/0x170 vfs_write+0xc7/0x1c0 SyS_write+0x58/0xc0 do_syscall_64+0x6c/0x1f0 return_from_SYSCALL_64+0x0/0x7a -> #1 (microcode_mutex){+.+.+.}: lock_acquire+0xc9/0x230 __mutex_lock+0x88/0x960 mutex_lock_nested+0x1b/0x20 microcode_init+0xbb/0x208 do_one_initcall+0x51/0x1a9 kernel_init_freeable+0x208/0x2a7 kernel_init+0xe/0x104 ret_from_fork+0x2a/0x40 -> #0 (cpu_hotplug_lock.rw_sem){++++++}: __lock_acquire+0x153c/0x1550 lock_acquire+0xc9/0x230 cpus_read_lock+0x4b/0x90 drain_all_stock.part.35+0x18/0x140 try_charge+0x3ab/0x6e0 mem_cgroup_try_charge+0x7f/0x2c0 shmem_getpage_gfp+0x25f/0x1050 shmem_fault+0x96/0x200 __do_fault+0x1e/0xa0 __handle_mm_fault+0x9c3/0xe00 handle_mm_fault+0x16e/0x380 __do_page_fault+0x24a/0x530 do_page_fault+0x30/0x80 page_fault+0x28/0x30 other info that might help us debug this: Chain exists of: cpu_hotplug_lock.rw_sem --> &type->i_mutex_dir_key#3 --> &mm->mmap_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&mm->mmap_sem); lock(&type->i_mutex_dir_key#3); lock(&mm->mmap_sem); lock(cpu_hotplug_lock.rw_sem); *** DEADLOCK *** 2 locks held by a.out/4771: #0: (&mm->mmap_sem){++++++}, at: [<ffffffff8106eb35>] __do_page_fault+0x175/0x530 #1: (percpu_charge_mutex){+.+...}, at: [<ffffffff812b4c97>] try_charge+0x397/0x6e0 The problem is very similar to the one fixed by commit a459eeb7 ("mm, page_alloc: do not depend on cpu hotplug locks inside the allocator"). We are taking hotplug locks while we can be sitting on top of basically arbitrary locks. This just calls for problems. We can get rid of {get,put}_online_cpus, fortunately. We do not have to be worried about races with memory hotplug because drain_local_stock, which is called from both the WQ draining and the memory hotplug contexts, is always operating on the local cpu stock with IRQs disabled. The only thing to be careful about is that the target memcg doesn't vanish while we are still in drain_all_stock so take a reference on it. Link: http://lkml.kernel.org/r/20170913090023.28322-1-mhocko@kernel.orgSigned-off-by: -
Michal Hocko authored
Andrea has noticed that the oom_reaper doesn't invalidate the range via mmu notifiers (mmu_notifier_invalidate_range_start/end) and that can corrupt the memory of the kvm guest for example. tlb_flush_mmu_tlbonly already invokes mmu notifiers but that is not sufficient as per Andrea: "mmu_notifier_invalidate_range cannot be used in replacement of mmu_notifier_invalidate_range_start/end. For KVM mmu_notifier_invalidate_range is a noop and rightfully so. A MMU notifier implementation has to implement either ->invalidate_range method or the invalidate_range_start/end methods, not both. And if you implement invalidate_range_start/end like KVM is forced to do, calling mmu_notifier_invalidate_range in common code is a noop for KVM. For those MMU notifiers that can get away only implementing ->invalidate_range, the ->invalidate_range is implicitly called by mmu_notifier_invalidate_range_end(). And only those secondary MMUs that share the same pagetable with the primary MMU (like AMD iommuv2) can get away only implementing ->invalidate_range" As the callback is allowed to sleep and the implementation is out of hand of the MM it is safer to simply bail out if there is an mmu notifier registered. In order to not fail too early make the mm_has_notifiers check under the oom_lock and have a little nap before failing to give the current oom victim some more time to exit. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20170913113427.2291-1-mhocko@kernel.org Fixes: aac45363 ("mm, oom: introduce oom reaper") Signed-off-by:
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Vitaly Wool authored
It is possible that on a (partially) unsuccessful page reclaim, kref_put() called in z3fold_reclaim_page() does not yield page release, but the page is released shortly afterwards by another thread. Then z3fold_reclaim_page() would try to list_add() that (released) page again which is obviously a bug. To avoid that, spin_lock() has to be taken earlier, before the kref_put() call mentioned earlier. Link: http://lkml.kernel.org/r/20170913162937.bfff21c7d12b12a5f47639fd@gmail.comSigned-off-by:
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