- 27 Mar, 2020 4 commits
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Lukas Wunner authored
Commit 7f980307 ("serial: 8250: Support console on software emulated rs485 ports") amended serial8250_console_write() with rs485 support, but positioned the invocation of ->rs485_stop_tx() after re-enablement of interrupts. The irq handler and ->console_write() are serialized with the port spinlock, so no problem there, but due to the rs485 delay, the irq handler may unnecessarily spin for a while. Avoid that by moving ->rs485_stop_tx() before re-enablement of interrupts, which also mirrors the order at the beginning of serial8250_console_write(). Signed-off-by:
Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/019839cb1f61b01210b6ff9ac9f9079ca77f8411.1585319447.git.lukas@wunner.deSigned-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Lukas Wunner authored
Due to a silly copy-paste mistake, commit 7f980307 ("serial: 8250: Support console on software emulated rs485 ports") erroneously pauses for the duration of delay_rts_before_send after writing to the console, instead of delay_rts_after_send. Mea culpa. Fixes: 7f980307 ("serial: 8250: Support console on software emulated rs485 ports") Signed-off-by:
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Eric Biggers authored
vt_in_use() dereferences console_driver->ttys[i] without proper locking. This is broken because the tty can be closed and freed concurrently. We could fix this by using 'READ_ONCE(console_driver->ttys[i]) != NULL' and skipping the check of tty_struct::count. But, looking at console_driver->ttys[i] isn't really appropriate anyway because even if it is NULL the tty can still be in the process of being closed. Instead, fix it by making vt_in_use() require console_lock() and check whether the vt is allocated and has port refcount > 1. This works since following the patch "vt: vt_ioctl: fix VT_DISALLOCATE freeing in-use virtual console" the port refcount is incremented while the vt is open. Reproducer (very unreliable, but it worked for me after a few minutes): #include <fcntl.h> #include <linux/vt.h> int main() { int fd, nproc; struct vt_stat state; char ttyname[16]; fd = open("/dev/tty10", O_RDONLY); for (nproc = 1; nproc < 8; nproc *= 2) fork(); for (;;) { sprintf(ttyname, "/dev/tty%d", rand() % 8); close(open(ttyname, O_RDONLY)); ioctl(fd, VT_GETSTATE, &state); } } KASAN report: BUG: KASAN: use-after-free in vt_in_use drivers/tty/vt/vt_ioctl.c:48 [inline] BUG: KASAN: use-after-free in vt_ioctl+0x1ad3/0x1d70 drivers/tty/vt/vt_ioctl.c:657 Read of size 4 at addr ffff888065722468 by task syz-vt2/132 CPU: 0 PID: 132 Comm: syz-vt2 Not tainted 5.6.0-rc5-00130-g089b6d36 #13 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20191223_100556-anatol 04/01/2014 Call Trace: [...] vt_in_use drivers/tty/vt/vt_ioctl.c:48 [inline] vt_ioctl+0x1ad3/0x1d70 drivers/tty/vt/vt_ioctl.c:657 tty_ioctl+0x9db/0x11b0 drivers/tty/tty_io.c:2660 [...] Allocated by task 136: [...] kzalloc include/linux/slab.h:669 [inline] alloc_tty_struct+0x96/0x8a0 drivers/tty/tty_io.c:2982 tty_init_dev+0x23/0x350 drivers/tty/tty_io.c:1334 tty_open_by_driver drivers/tty/tty_io.c:1987 [inline] tty_open+0x3ca/0xb30 drivers/tty/tty_io.c:2035 [...] Freed by task 41: [...] kfree+0xbf/0x200 mm/slab.c:3757 free_tty_struct+0x8d/0xb0 drivers/tty/tty_io.c:177 release_one_tty+0x22d/0x2f0 drivers/tty/tty_io.c:1468 process_one_work+0x7f1/0x14b0 kernel/workqueue.c:2264 worker_thread+0x8b/0xc80 kernel/workqueue.c:2410 [...] Fixes: 4001d7b7 ("vt: push down the tty lock so we can see what is left to tackle") Cc: <stable@vger.kernel.org> # v3.4+ Acked-by:Jiri Slaby <jslaby@suse.cz> Signed-off-by:
Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20200322034305.210082-3-ebiggers@kernel.orgSigned-off-by:
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Eric Biggers authored
The VT_DISALLOCATE ioctl can free a virtual console while tty_release() is still running, causing a use-after-free in con_shutdown(). This occurs because VT_DISALLOCATE considers a virtual console's 'struct vc_data' to be unused as soon as the corresponding tty's refcount hits 0. But actually it may be still being closed. Fix this by making vc_data be reference-counted via the embedded 'struct tty_port'. A newly allocated virtual console has refcount 1. Opening it for the first time increments the refcount to 2. Closing it for the last time decrements the refcount (in tty_operations::cleanup() so that it happens late enough), as does VT_DISALLOCATE. Reproducer: #include <fcntl.h> #include <linux/vt.h> #include <sys/ioctl.h> #include <unistd.h> int main() { if (fork()) { for (;;) close(open("/dev/tty5", O_RDWR)); } else { int fd = open("/dev/tty10", O_RDWR); for (;;) ioctl(fd, VT_DISALLOCATE, 5); } } KASAN report: BUG: KASAN: use-after-free in con_shutdown+0x76/0x80 drivers/tty/vt/vt.c:3278 Write of size 8 at addr ffff88806a4ec108 by task syz_vt/129 CPU: 0 PID: 129 Comm: syz_vt Not tainted 5.6.0-rc2 #11 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20191223_100556-anatol 04/01/2014 Call Trace: [...] con_shutdown+0x76/0x80 drivers/tty/vt/vt.c:3278 release_tty+0xa8/0x410 drivers/tty/tty_io.c:1514 tty_release_struct+0x34/0x50 drivers/tty/tty_io.c:1629 tty_release+0x984/0xed0 drivers/tty/tty_io.c:1789 [...] Allocated by task 129: [...] kzalloc include/linux/slab.h:669 [inline] vc_allocate drivers/tty/vt/vt.c:1085 [inline] vc_allocate+0x1ac/0x680 drivers/tty/vt/vt.c:1066 con_install+0x4d/0x3f0 drivers/tty/vt/vt.c:3229 tty_driver_install_tty drivers/tty/tty_io.c:1228 [inline] tty_init_dev+0x94/0x350 drivers/tty/tty_io.c:1341 tty_open_by_driver drivers/tty/tty_io.c:1987 [inline] tty_open+0x3ca/0xb30 drivers/tty/tty_io.c:2035 [...] Freed by task 130: [...] kfree+0xbf/0x1e0 mm/slab.c:3757 vt_disallocate drivers/tty/vt/vt_ioctl.c:300 [inline] vt_ioctl+0x16dc/0x1e30 drivers/tty/vt/vt_ioctl.c:818 tty_ioctl+0x9db/0x11b0 drivers/tty/tty_io.c:2660 [...] Fixes: 4001d7b7 ("vt: push down the tty lock so we can see what is left to tackle") Cc: <stable@vger.kernel.org> # v3.4+ Reported-by: syzbot+522643ab5729b0421998@syzkaller.appspotmail.com Acked-by:
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- 26 Mar, 2020 3 commits
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Chunyan Zhang authored
kbuild-test reported an error: config: mips-randconfig-a001-20200321 ... >> drivers/tty/serial/sprd_serial.c:1175: undefined reference to `clk_set_parent' Because some mips Kconfig selects HAVE_CLK but not COMMON_CLK and no clk_set_parent implemented, so the error was exposed. So adding dependence on COMMON_CLK can fix this issue. Fixes: 7ba87cfe ("tty: serial: make SERIAL_SPRD not depend on ARCH_SPRD") Reported-by:
kbuild test robot <lkp@intel.com> Signed-off-by:
Chunyan Zhang <chunyan.zhang@unisoc.com> Link: https://lore.kernel.org/r/20200325081427.20312-1-zhang.lyra@gmail.comSigned-off-by:
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Michael Walle authored
The return value of lpuart_dma_tx_request() is an negative errno on failure and zero on success. Fixes: 159381df ("tty: serial: fsl_lpuart: fix DMA operation when using IOMMU") Reported-by:
Leonard Crestez <leonard.crestez@nxp.com> Signed-off-by:
Michael Walle <michael@walle.cc> Reviewed-by:
Fugang Duan <fugang.duan@nxp.com> Link: https://lore.kernel.org/r/20200325090658.25967-2-michael@walle.ccSigned-off-by:
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Michael Walle authored
Move dma_request_chan() out of the atomic context. First this call should not be in the atomic context at all and second the dev_info_once() may cause a hang because because the console takes this spinlock, too. Fixes: 159381df ("tty: serial: fsl_lpuart: fix DMA operation when using IOMMU") Reported-by:
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- 24 Mar, 2020 19 commits
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Lubomir Rintel authored
ralink,rt2880-uart is compatible with ns16550a and all other instances of RT2880 UART nodes include it in the compatible property. Add it also here, to make the binding schema simpler. Signed-off-by:
Lubomir Rintel <lkundrak@v3.sk> Reviewed-by:
Rob Herring <robh@kernel.org> Acked-by:
Mans Rullgard <mans@mansr.com> Link: https://lore.kernel.org/r/20200320174107.29406-8-lkundrak@v3.skSigned-off-by:
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Lubomir Rintel authored
XScale serial port driver is perfectly capable of supporting this hardware. A separate compatible string is probably a historical mess. Signed-off-by:
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Lubomir Rintel authored
A preferred node name for serial ports is "serial": mmp2-olpc-xo-1-75.dt.yaml: uart@d4030000: $nodename:0: 'uart@d4030000' does not match '^serial(@[0-9a-f,]+)*$' ... Signed-off-by: -
Lubomir Rintel authored
Extend the nodes by their phandle references instead of recreating the tree and declaring references of the same names. Signed-off-by:
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Lubomir Rintel authored
Some drivers that claim to support mrvl,mmp-uart default to a reg-shift of two, some don't. Be explicit to be on a safe side. With that in place, a XScale serial port driver is perfectly capable of supporting the MMP serial port. Add a compatible string. Signed-off-by:
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Lubomir Rintel authored
There's a preferred node name for serial ports, and it's not "uart": pxa910-dkb.dt.yaml: uart@d4017000: $nodename:0: 'uart@d4017000' does not match '^serial(@[0-9a-f,]+)*$' ... Signed-off-by: -
Lubomir Rintel authored
Extend the nodes by their phandle references instead of recreating the tree and declaring references of the same names. Signed-off-by:
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Uwe Kleine-König authored
The definitons in the dt-binding's gpio header only contains some constants to be used in device trees. It is not relevant for omap-serial (as the gpio API hides the details) and in fact unused so it can just be dropped. Signed-off-by:
Uwe Kleine-König <uwe@kleine-koenig.org> Link: https://lore.kernel.org/r/20200321204031.30369-1-uwe@kleine-koenig.orgSigned-off-by:
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Vignesh Raghavendra authored
UART on K3 SoCs has configurable RX timeout behavior (controlled via EFR2) and better DMA integration. This allows to transfer as larger amount data per DMA transfer compared to older SoCs. Add support for the same. Signed-off-by:
Vignesh Raghavendra <vigneshr@ti.com> Link: https://lore.kernel.org/r/20200319110344.21348-7-vigneshr@ti.comSigned-off-by:
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Vignesh Raghavendra authored
As per Advisory 27 of AM437x Silicon errata document, Spurious UART interrupts may occur when DMA mode (FCR.DMA_MODE) is enabled. The Interrupt Controller flags that a UART interrupt has occurred; however, the associated IT_PENDING bit remains set to 1, indicating that no interrupt is pending. Acknowledge the spurious interrupts for every occurrence as workaround. Errata is applicable to all TI SoCs with this IP. Signed-off-by:
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Vignesh Raghavendra authored
Although same 8250 compliant UART IP is reused across different SoC, their integration wrt DMA varies greatly across SoCs. Therefore, different SoC may need to use different FIFO trigger level for DMA event and DMA configuration parameters. Provide a way to pass this information via driver data. This is required to support UART DMA on AM654/J721e SoCs. Signed-off-by:
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Peter Ujfalusi authored
Caller functions of __dma_rx_do_complete() already hold rx_dma_lock. Therefore move locking out of the function to avoid need to release and reacquire lock. Signed-off-by:
Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by:
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Vignesh Raghavendra authored
Take into account data stuck in DMA internal buffers before pushing data to higher layer. dma_tx_state has "in_flight_bytes" member that provides this information. Signed-off-by:
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Vignesh Raghavendra authored
Terminate and flush DMA internal buffers, before pushing RX data to higher layer. Otherwise, this will lead to data corruption, as driver would end up pushing stale buffer data to higher layer while actual data is still stuck inside DMA hardware and has yet not arrived at the memory. While at that, replace deprecated dmaengine_terminate_all() with dmaengine_terminate_async(). Signed-off-by:
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Peter Ujfalusi authored
When booting j721e the following bug is printed: [ 1.154821] BUG: sleeping function called from invalid context at kernel/sched/completion.c:99 [ 1.154827] in_atomic(): 0, irqs_disabled(): 128, non_block: 0, pid: 12, name: kworker/0:1 [ 1.154832] 3 locks held by kworker/0:1/12: [ 1.154836] #0: ffff000840030728 ((wq_completion)events){+.+.}, at: process_one_work+0x1d4/0x6e8 [ 1.154852] #1: ffff80001214fdd8 (deferred_probe_work){+.+.}, at: process_one_work+0x1d4/0x6e8 [ 1.154860] #2: ffff00084060b170 (&dev->mutex){....}, at: __device_attach+0x38/0x138 [ 1.154872] irq event stamp: 63096 [ 1.154881] hardirqs last enabled at (63095): [<ffff800010b74318>] _raw_spin_unlock_irqrestore+0x70/0x78 [ 1.154887] hardirqs last disabled at (63096): [<ffff800010b740d8>] _raw_spin_lock_irqsave+0x28/0x80 [ 1.154893] softirqs last enabled at (62254): [<ffff800010080c88>] _stext+0x488/0x564 [ 1.154899] softirqs last disabled at (62247): [<ffff8000100fdb3c>] irq_exit+0x114/0x140 [ 1.154906] CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.6.0-rc6-next-20200318-00094-g45e4089b0bd3 #221 [ 1.154911] Hardware name: Texas Instruments K3 J721E SoC (DT) [ 1.154917] Workqueue: events deferred_probe_work_func [ 1.154923] Call trace: [ 1.154928] dump_backtrace+0x0/0x190 [ 1.154933] show_stack+0x14/0x20 [ 1.154940] dump_stack+0xe0/0x148 [ 1.154946] ___might_sleep+0x150/0x1f0 [ 1.154952] __might_sleep+0x4c/0x80 [ 1.154957] wait_for_completion_timeout+0x40/0x140 [ 1.154964] ti_sci_set_device_state+0xa0/0x158 [ 1.154969] ti_sci_cmd_get_device_exclusive+0x14/0x20 [ 1.154977] ti_sci_dev_start+0x34/0x50 [ 1.154984] genpd_runtime_resume+0x78/0x1f8 [ 1.154991] __rpm_callback+0x3c/0x140 [ 1.154996] rpm_callback+0x20/0x80 [ 1.155001] rpm_resume+0x568/0x758 [ 1.155007] __pm_runtime_resume+0x44/0xb0 [ 1.155013] omap8250_probe+0x2b4/0x508 [ 1.155019] platform_drv_probe+0x50/0xa0 [ 1.155023] really_probe+0xd4/0x318 [ 1.155028] driver_probe_device+0x54/0xe8 [ 1.155033] __device_attach_driver+0x80/0xb8 [ 1.155039] bus_for_each_drv+0x74/0xc0 [ 1.155044] __device_attach+0xdc/0x138 [ 1.155049] device_initial_probe+0x10/0x18 [ 1.155053] bus_probe_device+0x98/0xa0 [ 1.155058] deferred_probe_work_func+0x74/0xb0 [ 1.155063] process_one_work+0x280/0x6e8 [ 1.155068] worker_thread+0x48/0x430 [ 1.155073] kthread+0x108/0x138 [ 1.155079] ret_from_fork+0x10/0x18 To fix the bug we need to first call pm_runtime_enable() prior to any pm_runtime calls. Reported-by:Tomi Valkeinen <tomi.valkeinen@ti.com> Signed-off-by:
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Vignesh Raghavendra authored
Call stop_rx() to halt reception when throttle is requested. Update unthrottle callback to restart reception. Signed-off-by:
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Vignesh Raghavendra authored
When port's throttle callback is called, it should stop pushing any more data into TTY buffer to avoid buffer overflow. This means driver has to stop HW from receiving more data and assert the HW flow control. For UARTs with auto HW flow control (such as 8250_omap) manual assertion of flow control line is not possible and only way is to allow RX FIFO to fill up, thus trigger auto HW flow control logic. Therefore make sure that 8250 generic IRQ handler does not drain data when port is stopped (i.e UART_LSR_DR is unset in read_status_mask). Not servicing, RX FIFO would trigger auto HW flow control when FIFO occupancy reaches preset threshold, thus halting RX. Since, error conditions in UART_LSR register are cleared just by reading the register, data has to be drained in case there are FIFO errors, else error information will lost. Signed-off-by:
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Raviteja Narayanam authored
Make sure that all bytes are transmitted out of Uart by monitoring CDNS_UART_SR_TACTIVE bit as well. Signed-off-by:
Raviteja Narayanam <raviteja.narayanam@xilinx.com> Signed-off-by:
Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> Acked-by:
Maarten Brock <m.brock@vanmierlo.com> Link: https://lore.kernel.org/r/e2514818af5973be291cc117d07739f068b71639.1584610774.git.shubhrajyoti.datta@xilinx.comSigned-off-by:
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Raviteja Narayanam authored
set_termios function should not wait for the transmit FIFO empty (CDNS_UART_SR_TXEMPTY) unconditionally. The tty layer takes care of it based on the parameter passed (TCSANOW/TCSADRAIN/TCSAFLUSH). Signed-off-by:
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- 23 Mar, 2020 2 commits
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Greg Kroah-Hartman authored
We need the tty fixes in here as well. Signed-off-by: -
Linus Torvalds authored
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- 22 Mar, 2020 12 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linuxLinus Torvalds authored
Pull btrfs fixes from David Sterba: "Two fixes. The first is a regression: when dropping some incompat bits the conditions were reversed. The other is a fix for rename whiteout potentially leaving stack memory linked to a list" * tag 'for-5.6-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix removal of raid[56|1c34} incompat flags after removing block group btrfs: fix log context list corruption after rename whiteout error
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Linus Torvalds authored
Merge misc fixes from Andrew Morton: "10 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: x86/mm: split vmalloc_sync_all() mm, slub: prevent kmalloc_node crashes and memory leaks mm/mmu_notifier: silence PROVE_RCU_LIST warnings epoll: fix possible lost wakeup on epoll_ctl() path mm: do not allow MADV_PAGEOUT for CoW pages mm, memcg: throttle allocators based on ancestral memory.high mm, memcg: fix corruption on 64-bit divisor in memory.high throttling page-flags: fix a crash at SetPageError(THP_SWAP) mm/hotplug: fix hot remove failure in SPARSEMEM|!VMEMMAP case memcg: fix NULL pointer dereference in __mem_cgroup_usage_unregister_event
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Joerg Roedel authored
Commit 3f8fd02b ("mm/vmalloc: Sync unmappings in __purge_vmap_area_lazy()") introduced a call to vmalloc_sync_all() in the vunmap() code-path. While this change was necessary to maintain correctness on x86-32-pae kernels, it also adds additional cycles for architectures that don't need it. Specifically on x86-64 with CONFIG_VMAP_STACK=y some people reported severe performance regressions in micro-benchmarks because it now also calls the x86-64 implementation of vmalloc_sync_all() on vunmap(). But the vmalloc_sync_all() implementation on x86-64 is only needed for newly created mappings. To avoid the unnecessary work on x86-64 and to gain the performance back, split up vmalloc_sync_all() into two functions: * vmalloc_sync_mappings(), and * vmalloc_sync_unmappings() Most call-sites to vmalloc_sync_all() only care about new mappings being synchronized. The only exception is the new call-site added in the above mentioned commit. Shile Zhang directed us to a report of an 80% regression in reaim throughput. Fixes: 3f8fd02b ("mm/vmalloc: Sync unmappings in __purge_vmap_area_lazy()") Reported-by:
kernel test robot <oliver.sang@intel.com> Reported-by:
Shile Zhang <shile.zhang@linux.alibaba.com> Signed-off-by:
Joerg Roedel <jroedel@suse.de> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Tested-by:
Borislav Petkov <bp@suse.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [GHES] Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20191009124418.8286-1-joro@8bytes.org Link: https://lists.01.org/hyperkitty/list/lkp@lists.01.org/thread/4D3JPPHBNOSPFK2KEPC6KGKS6J25AIDB/ Link: http://lkml.kernel.org/r/20191113095530.228959-1-shile.zhang@linux.alibaba.comSigned-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Vlastimil Babka authored
Sachin reports [1] a crash in SLUB __slab_alloc(): BUG: Kernel NULL pointer dereference on read at 0x000073b0 Faulting instruction address: 0xc0000000003d55f4 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: CPU: 19 PID: 1 Comm: systemd Not tainted 5.6.0-rc2-next-20200218-autotest #1 NIP: c0000000003d55f4 LR: c0000000003d5b94 CTR: 0000000000000000 REGS: c0000008b37836d0 TRAP: 0300 Not tainted (5.6.0-rc2-next-20200218-autotest) MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 24004844 XER: 00000000 CFAR: c00000000000dec4 DAR: 00000000000073b0 DSISR: 40000000 IRQMASK: 1 GPR00: c0000000003d5b94 c0000008b3783960 c00000000155d400 c0000008b301f500 GPR04: 0000000000000dc0 0000000000000002 c0000000003443d8 c0000008bb398620 GPR08: 00000008ba2f0000 0000000000000001 0000000000000000 0000000000000000 GPR12: 0000000024004844 c00000001ec52a00 0000000000000000 0000000000000000 GPR16: c0000008a1b20048 c000000001595898 c000000001750c18 0000000000000002 GPR20: c000000001750c28 c000000001624470 0000000fffffffe0 5deadbeef0000122 GPR24: 0000000000000001 0000000000000dc0 0000000000000002 c0000000003443d8 GPR28: c0000008b301f500 c0000008bb398620 0000000000000000 c00c000002287180 NIP ___slab_alloc+0x1f4/0x760 LR __slab_alloc+0x34/0x60 Call Trace: ___slab_alloc+0x334/0x760 (unreliable) __slab_alloc+0x34/0x60 __kmalloc_node+0x110/0x490 kvmalloc_node+0x58/0x110 mem_cgroup_css_online+0x108/0x270 online_css+0x48/0xd0 cgroup_apply_control_enable+0x2ec/0x4d0 cgroup_mkdir+0x228/0x5f0 kernfs_iop_mkdir+0x90/0xf0 vfs_mkdir+0x110/0x230 do_mkdirat+0xb0/0x1a0 system_call+0x5c/0x68 This is a PowerPC platform with following NUMA topology: available: 2 nodes (0-1) node 0 cpus: node 0 size: 0 MB node 0 free: 0 MB node 1 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 node 1 size: 35247 MB node 1 free: 30907 MB node distances: node 0 1 0: 10 40 1: 40 10 possible numa nodes: 0-31 This only happens with a mmotm patch "mm/memcontrol.c: allocate shrinker_map on appropriate NUMA node" [2] which effectively calls kmalloc_node for each possible node. SLUB however only allocates kmem_cache_node on online N_NORMAL_MEMORY nodes, and relies on node_to_mem_node to return such valid node for other nodes since commit a561ce00 ("slub: fall back to node_to_mem_node() node if allocating on memoryless node"). This is however not true in this configuration where the _node_numa_mem_ array is not initialized for nodes 0 and 2-31, thus it contains zeroes and get_partial() ends up accessing non-allocated kmem_cache_node. A related issue was reported by Bharata (originally by Ramachandran) [3] where a similar PowerPC configuration, but with mainline kernel without patch [2] ends up allocating large amounts of pages by kmalloc-1k kmalloc-512. This seems to have the same underlying issue with node_to_mem_node() not behaving as expected, and might probably also lead to an infinite loop with CONFIG_SLUB_CPU_PARTIAL [4]. This patch should fix both issues by not relying on node_to_mem_node() anymore and instead simply falling back to NUMA_NO_NODE, when kmalloc_node(node) is attempted for a node that's not online, or has no usable memory. The "usable memory" condition is also changed from node_present_pages() to N_NORMAL_MEMORY node state, as that is exactly the condition that SLUB uses to allocate kmem_cache_node structures. The check in get_partial() is removed completely, as the checks in ___slab_alloc() are now sufficient to prevent get_partial() being reached with an invalid node. [1] https://lore.kernel.org/linux-next/3381CD91-AB3D-4773-BA04-E7A072A63968@linux.vnet.ibm.com/ [2] https://lore.kernel.org/linux-mm/fff0e636-4c36-ed10-281c-8cdb0687c839@virtuozzo.com/ [3] https://lore.kernel.org/linux-mm/20200317092624.GB22538@in.ibm.com/ [4] https://lore.kernel.org/linux-mm/088b5996-faae-8a56-ef9c-5b567125ae54@suse.cz/ Fixes: a561ce00 ("slub: fall back to node_to_mem_node() node if allocating on memoryless node") Reported-by:Sachin Sant <sachinp@linux.vnet.ibm.com> Reported-by:
PUVICHAKRAVARTHY RAMACHANDRAN <puvichakravarthy@in.ibm.com> Signed-off-by:
Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
Bharata B Rao <bharata@linux.ibm.com> Reviewed-by:
Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@kernel.org> Cc: Christopher Lameter <cl@linux.com> Cc: linuxppc-dev@lists.ozlabs.org Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Nathan Lynch <nathanl@linux.ibm.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20200320115533.9604-1-vbabka@suse.czDebugged-by:
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Qian Cai authored
It is safe to traverse mm->notifier_subscriptions->list either under SRCU read lock or mm->notifier_subscriptions->lock using hlist_for_each_entry_rcu(). Silence the PROVE_RCU_LIST false positives, for example, WARNING: suspicious RCU usage ----------------------------- mm/mmu_notifier.c:484 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 3 locks held by libvirtd/802: #0: ffff9321e3f58148 (&mm->mmap_sem#2){++++}, at: do_mprotect_pkey+0xe1/0x3e0 #1: ffffffff91ae6160 (mmu_notifier_invalidate_range_start){+.+.}, at: change_p4d_range+0x5fa/0x800 #2: ffffffff91ae6e08 (srcu){....}, at: __mmu_notifier_invalidate_range_start+0x178/0x460 stack backtrace: CPU: 7 PID: 802 Comm: libvirtd Tainted: G I 5.6.0-rc6-next-20200317+ #2 Hardware name: HP ProLiant BL460c Gen8, BIOS I31 11/02/2014 Call Trace: dump_stack+0xa4/0xfe lockdep_rcu_suspicious+0xeb/0xf5 __mmu_notifier_invalidate_range_start+0x3ff/0x460 change_p4d_range+0x746/0x800 change_protection+0x1df/0x300 mprotect_fixup+0x245/0x3e0 do_mprotect_pkey+0x23b/0x3e0 __x64_sys_mprotect+0x51/0x70 do_syscall_64+0x91/0xae8 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Signed-off-by:Qian Cai <cai@lca.pw> Signed-off-by:
Paul E. McKenney <paulmck@kernel.org> Reviewed-by:
Jason Gunthorpe <jgg@mellanox.com> Link: http://lkml.kernel.org/r/20200317175640.2047-1-cai@lca.pwSigned-off-by:
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Roman Penyaev authored
This fixes possible lost wakeup introduced by commit a218cc49. Originally modifications to ep->wq were serialized by ep->wq.lock, but in commit a218cc49 ("epoll: use rwlock in order to reduce ep_poll_callback() contention") a new rw lock was introduced in order to relax fd event path, i.e. callers of ep_poll_callback() function. After the change ep_modify and ep_insert (both are called on epoll_ctl() path) were switched to ep->lock, but ep_poll (epoll_wait) was using ep->wq.lock on wqueue list modification. The bug doesn't lead to any wqueue list corruptions, because wake up path and list modifications were serialized by ep->wq.lock internally, but actual waitqueue_active() check prior wake_up() call can be reordered with modifications of ep ready list, thus wake up can be lost. And yes, can be healed by explicit smp_mb(): list_add_tail(&epi->rdlink, &ep->rdllist); smp_mb(); if (waitqueue_active(&ep->wq)) wake_up(&ep->wp); But let's make it simple, thus current patch replaces ep->wq.lock with the ep->lock for wqueue modifications, thus wake up path always observes activeness of the wqueue correcty. Fixes: a218cc49 ("epoll: use rwlock in order to reduce ep_poll_callback() contention") Reported-by:
Max Neunhoeffer <max@arangodb.com> Signed-off-by:
Roman Penyaev <rpenyaev@suse.de> Signed-off-by:
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Michal Hocko authored
Jann has brought up a very interesting point [1]. While shared pages are excluded from MADV_PAGEOUT normally, CoW pages can be easily reclaimed that way. This can lead to all sorts of hard to debug problems. E.g. performance problems outlined by Daniel [2]. There are runtime environments where there is a substantial memory shared among security domains via CoW memory and a easy to reclaim way of that memory, which MADV_{COLD,PAGEOUT} offers, can lead to either performance degradation in for the parent process which might be more privileged or even open side channel attacks. The feasibility of the latter is not really clear to me TBH but there is no real reason for exposure at this stage. It seems there is no real use case to depend on reclaiming CoW memory via madvise at this stage so it is much easier to simply disallow it and this is what this patch does. Put it simply MADV_{PAGEOUT,COLD} can operate only on the exclusively owned memory which is a straightforward semantic. [1] http://lkml.kernel.org/r/CAG48ez0G3JkMq61gUmyQAaCq=_TwHbi1XKzWRooxZkv08PQKuw@mail.gmail.com [2] http://lkml.kernel.org/r/CAKOZueua_v8jHCpmEtTB6f3i9e2YnmX4mqdYVWhV4E=Z-n+zRQ@mail.gmail.com Fixes: 9c276cc6 ("mm: introduce MADV_COLD") Reported-by:Jann Horn <jannh@google.com> Signed-off-by:
Michal Hocko <mhocko@suse.com> Signed-off-by:
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Chris Down authored
Prior to this commit, we only directly check the affected cgroup's memory.high against its usage. However, it's possible that we are being reclaimed as a result of hitting an ancestor memory.high and should be penalised based on that, instead. This patch changes memory.high overage throttling to use the largest overage in its ancestors when considering how many penalty jiffies to charge. This makes sure that we penalise poorly behaving cgroups in the same way regardless of at what level of the hierarchy memory.high was breached. Fixes: 0e4b01df ("mm, memcg: throttle allocators when failing reclaim over memory.high") Reported-by:
Johannes Weiner <hannes@cmpxchg.org> Signed-off-by:
Chris Down <chris@chrisdown.name> Signed-off-by:
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Chris Down authored
Commit 0e4b01df had a bunch of fixups to use the right division method. However, it seems that after all that it still wasn't right -- div_u64 takes a 32-bit divisor. The headroom is still large (2^32 pages), so on mundane systems you won't hit this, but this should definitely be fixed. Fixes: 0e4b01df ("mm, memcg: throttle allocators when failing reclaim over memory.high") Reported-by:
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Qian Cai authored
Commit bd4c82c2 ("mm, THP, swap: delay splitting THP after swapped out") supported writing THP to a swap device but forgot to upgrade an older commit df8c94d1 ("page-flags: define behavior of FS/IO-related flags on compound pages") which could trigger a crash during THP swapping out with DEBUG_VM_PGFLAGS=y, kernel BUG at include/linux/page-flags.h:317! page dumped because: VM_BUG_ON_PAGE(1 && PageCompound(page)) page:fffff3b2ec3a8000 refcount:512 mapcount:0 mapping:000000009eb0338c index:0x7f6e58200 head:fffff3b2ec3a8000 order:9 compound_mapcount:0 compound_pincount:0 anon flags: 0x45fffe0000d8454(uptodate|lru|workingset|owner_priv_1|writeback|head|reclaim|swapbacked) end_swap_bio_write() SetPageError(page) VM_BUG_ON_PAGE(1 && PageCompound(page)) <IRQ> bio_endio+0x297/0x560 dec_pending+0x218/0x430 [dm_mod] clone_endio+0xe4/0x2c0 [dm_mod] bio_endio+0x297/0x560 blk_update_request+0x201/0x920 scsi_end_request+0x6b/0x4b0 scsi_io_completion+0x509/0x7e0 scsi_finish_command+0x1ed/0x2a0 scsi_softirq_done+0x1c9/0x1d0 __blk_mqnterrupt+0xf/0x20 </IRQ> Fix by checking PF_NO_TAIL in those places instead. Fixes: bd4c82c2 ("mm, THP, swap: delay splitting THP after swapped out") Signed-off-by:
David Hildenbrand <david@redhat.com> Acked-by:
"Huang, Ying" <ying.huang@intel.com> Acked-by:
Rafael Aquini <aquini@redhat.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20200310235846.1319-1-cai@lca.pwSigned-off-by:
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Baoquan He authored
In section_deactivate(), pfn_to_page() doesn't work any more after ms->section_mem_map is resetting to NULL in SPARSEMEM|!VMEMMAP case. It causes a hot remove failure: kernel BUG at mm/page_alloc.c:4806! invalid opcode: 0000 [#1] SMP PTI CPU: 3 PID: 8 Comm: kworker/u16:0 Tainted: G W 5.5.0-next-20200205+ #340 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 Workqueue: kacpi_hotplug acpi_hotplug_work_fn RIP: 0010:free_pages+0x85/0xa0 Call Trace: __remove_pages+0x99/0xc0 arch_remove_memory+0x23/0x4d try_remove_memory+0xc8/0x130 __remove_memory+0xa/0x11 acpi_memory_device_remove+0x72/0x100 acpi_bus_trim+0x55/0x90 acpi_device_hotplug+0x2eb/0x3d0 acpi_hotplug_work_fn+0x1a/0x30 process_one_work+0x1a7/0x370 worker_thread+0x30/0x380 kthread+0x112/0x130 ret_from_fork+0x35/0x40 Let's move the ->section_mem_map resetting after depopulate_section_memmap() to fix it. [akpm@linux-foundation.org: remove unneeded initialization, per David] Fixes: ba72b4c8 ("mm/sparsemem: support sub-section hotplug") Signed-off-by:
Baoquan He <bhe@redhat.com> Signed-off-by:
Pankaj Gupta <pankaj.gupta.linux@gmail.com> Reviewed-by:
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Chunguang Xu authored
An eventfd monitors multiple memory thresholds of the cgroup, closes them, the kernel deletes all events related to this eventfd. Before all events are deleted, another eventfd monitors the memory threshold of this cgroup, leading to a crash: BUG: kernel NULL pointer dereference, address: 0000000000000004 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 800000033058e067 P4D 800000033058e067 PUD 3355ce067 PMD 0 Oops: 0002 [#1] SMP PTI CPU: 2 PID: 14012 Comm: kworker/2:6 Kdump: loaded Not tainted 5.6.0-rc4 #3 Hardware name: LENOVO 20AWS01K00/20AWS01K00, BIOS GLET70WW (2.24 ) 05/21/2014 Workqueue: events memcg_event_remove RIP: 0010:__mem_cgroup_usage_unregister_event+0xb3/0x190 RSP: 0018:ffffb47e01c4fe18 EFLAGS: 00010202 RAX: 0000000000000001 RBX: ffff8bb223a8a000 RCX: 0000000000000001 RDX: 0000000000000001 RSI: ffff8bb22fb83540 RDI: 0000000000000001 RBP: ffffb47e01c4fe48 R08: 0000000000000000 R09: 0000000000000010 R10: 000000000000000c R11: 071c71c71c71c71c R12: ffff8bb226aba880 R13: ffff8bb223a8a480 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8bb242680000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000004 CR3: 000000032c29c003 CR4: 00000000001606e0 Call Trace: memcg_event_remove+0x32/0x90 process_one_work+0x172/0x380 worker_thread+0x49/0x3f0 kthread+0xf8/0x130 ret_from_fork+0x35/0x40 CR2: 0000000000000004 We can reproduce this problem in the following ways: 1. We create a new cgroup subdirectory and a new eventfd, and then we monitor multiple memory thresholds of the cgroup through this eventfd. 2. closing this eventfd, and __mem_cgroup_usage_unregister_event () will be called multiple times to delete all events related to this eventfd. The first time __mem_cgroup_usage_unregister_event() is called, the kernel will clear all items related to this eventfd in thresholds-> primary. Since there is currently only one eventfd, thresholds-> primary becomes empty, so the kernel will set thresholds-> primary and hresholds-> spare to NULL. If at this time, the user creates a new eventfd and monitor the memory threshold of this cgroup, kernel will re-initialize thresholds-> primary. Then when __mem_cgroup_usage_unregister_event () is called for the second time, because thresholds-> primary is not empty, the system will access thresholds-> spare, but thresholds-> spare is NULL, which will trigger a crash. In general, the longer it takes to delete all events related to this eventfd, the easier it is to trigger this problem. The solution is to check whether the thresholds associated with the eventfd has been cleared when deleting the event. If so, we do nothing. [akpm@linux-foundation.org: fix comment, per Kirill] Fixes: 907860ed ("cgroups: make cftype.unregister_event() void-returning") Signed-off-by:Chunguang Xu <brookxu@tencent.com> Signed-off-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/077a6f67-aefa-4591-efec-f2f3af2b0b02@gmail.comSigned-off-by:
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