/* * Copyright (C) 2016 National Instruments Corp. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include #include #include #include #include #include #define NIWD_CONTROL 0x01 #define NIWD_COUNTER2 0x02 #define NIWD_COUNTER1 0x03 #define NIWD_COUNTER0 0x04 #define NIWD_SEED2 0x05 #define NIWD_SEED1 0x06 #define NIWD_SEED0 0x07 #define NIWD_IO_SIZE 0x08 #define NIWD_CONTROL_MODE 0x80 #define NIWD_CONTROL_PROC_RESET 0x20 #define NIWD_CONTROL_PET 0x10 #define NIWD_CONTROL_RUNNING 0x08 #define NIWD_CONTROL_CAPTURECOUNTER 0x04 #define NIWD_CONTROL_RESET 0x02 #define NIWD_CONTROL_ALARM 0x01 #define NIWD_PERIOD_NS 30720 #define NIWD_MIN_TIMEOUT 1 #define NIWD_MAX_TIMEOUT 515 #define NIWD_DEFAULT_TIMEOUT 60 #define NIWD_NAME "ni903x_wdt" struct ni903x_wdt { struct device *dev; u16 io_base; struct watchdog_device wdd; }; static unsigned int timeout; module_param(timeout, uint, 0); MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (default=" __MODULE_STRING(NIWD_DEFAULT_TIMEOUT) ")"); static int nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, int, S_IRUGO); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); static void ni903x_start(struct ni903x_wdt *wdt) { u8 control = inb(wdt->io_base + NIWD_CONTROL); outb(control | NIWD_CONTROL_RESET, wdt->io_base + NIWD_CONTROL); outb(control | NIWD_CONTROL_PET, wdt->io_base + NIWD_CONTROL); } static int ni903x_wdd_set_timeout(struct watchdog_device *wdd, unsigned int timeout) { struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd); u32 counter = timeout * (1000000000 / NIWD_PERIOD_NS); outb(((0x00FF0000 & counter) >> 16), wdt->io_base + NIWD_SEED2); outb(((0x0000FF00 & counter) >> 8), wdt->io_base + NIWD_SEED1); outb((0x000000FF & counter), wdt->io_base + NIWD_SEED0); wdd->timeout = timeout; return 0; } static unsigned int ni903x_wdd_get_timeleft(struct watchdog_device *wdd) { struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd); u8 control, counter0, counter1, counter2; u32 counter; control = inb(wdt->io_base + NIWD_CONTROL); control |= NIWD_CONTROL_CAPTURECOUNTER; outb(control, wdt->io_base + NIWD_CONTROL); counter2 = inb(wdt->io_base + NIWD_COUNTER2); counter1 = inb(wdt->io_base + NIWD_COUNTER1); counter0 = inb(wdt->io_base + NIWD_COUNTER0); counter = (counter2 << 16) | (counter1 << 8) | counter0; return counter / (1000000000 / NIWD_PERIOD_NS); } static int ni903x_wdd_ping(struct watchdog_device *wdd) { struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd); u8 control; control = inb(wdt->io_base + NIWD_CONTROL); outb(control | NIWD_CONTROL_PET, wdt->io_base + NIWD_CONTROL); return 0; } static int ni903x_wdd_start(struct watchdog_device *wdd) { struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd); outb(NIWD_CONTROL_RESET | NIWD_CONTROL_PROC_RESET, wdt->io_base + NIWD_CONTROL); ni903x_wdd_set_timeout(wdd, wdd->timeout); ni903x_start(wdt); return 0; } static int ni903x_wdd_stop(struct watchdog_device *wdd) { struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd); outb(NIWD_CONTROL_RESET, wdt->io_base + NIWD_CONTROL); return 0; } static acpi_status ni903x_resources(struct acpi_resource *res, void *data) { struct ni903x_wdt *wdt = data; u16 io_size; switch (res->type) { case ACPI_RESOURCE_TYPE_IO: if (wdt->io_base != 0) { dev_err(wdt->dev, "too many IO resources\n"); return AE_ERROR; } wdt->io_base = res->data.io.minimum; io_size = res->data.io.address_length; if (io_size < NIWD_IO_SIZE) { dev_err(wdt->dev, "memory region too small\n"); return AE_ERROR; } if (!devm_request_region(wdt->dev, wdt->io_base, io_size, NIWD_NAME)) { dev_err(wdt->dev, "failed to get memory region\n"); return AE_ERROR; } return AE_OK; case ACPI_RESOURCE_TYPE_END_TAG: default: /* Ignore unsupported resources, e.g. IRQ */ return AE_OK; } } static const struct watchdog_info ni903x_wdd_info = { .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, .identity = "NI Watchdog", }; static const struct watchdog_ops ni903x_wdd_ops = { .owner = THIS_MODULE, .start = ni903x_wdd_start, .stop = ni903x_wdd_stop, .ping = ni903x_wdd_ping, .set_timeout = ni903x_wdd_set_timeout, .get_timeleft = ni903x_wdd_get_timeleft, }; static int ni903x_acpi_add(struct acpi_device *device) { struct device *dev = &device->dev; struct watchdog_device *wdd; struct ni903x_wdt *wdt; acpi_status status; int ret; wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); if (!wdt) return -ENOMEM; device->driver_data = wdt; wdt->dev = dev; status = acpi_walk_resources(device->handle, METHOD_NAME__CRS, ni903x_resources, wdt); if (ACPI_FAILURE(status) || wdt->io_base == 0) { dev_err(dev, "failed to get resources\n"); return -ENODEV; } wdd = &wdt->wdd; wdd->info = &ni903x_wdd_info; wdd->ops = &ni903x_wdd_ops; wdd->min_timeout = NIWD_MIN_TIMEOUT; wdd->max_timeout = NIWD_MAX_TIMEOUT; wdd->timeout = NIWD_DEFAULT_TIMEOUT; wdd->parent = dev; watchdog_set_drvdata(wdd, wdt); watchdog_set_nowayout(wdd, nowayout); ret = watchdog_init_timeout(wdd, timeout, dev); if (ret) dev_err(dev, "unable to set timeout value, using default\n"); ret = watchdog_register_device(wdd); if (ret) { dev_err(dev, "failed to register watchdog\n"); return ret; } /* Switch from boot mode to user mode */ outb(NIWD_CONTROL_RESET | NIWD_CONTROL_MODE, wdt->io_base + NIWD_CONTROL); dev_dbg(dev, "io_base=0x%04X, timeout=%d, nowayout=%d\n", wdt->io_base, timeout, nowayout); return 0; } static int ni903x_acpi_remove(struct acpi_device *device) { struct ni903x_wdt *wdt = acpi_driver_data(device); ni903x_wdd_stop(&wdt->wdd); watchdog_unregister_device(&wdt->wdd); return 0; } static const struct acpi_device_id ni903x_device_ids[] = { {"NIC775C", 0}, {"", 0}, }; MODULE_DEVICE_TABLE(acpi, ni903x_device_ids); static struct acpi_driver ni903x_acpi_driver = { .name = NIWD_NAME, .ids = ni903x_device_ids, .ops = { .add = ni903x_acpi_add, .remove = ni903x_acpi_remove, }, }; module_acpi_driver(ni903x_acpi_driver); MODULE_DESCRIPTION("NI 903x Watchdog"); MODULE_AUTHOR("Jeff Westfahl "); MODULE_AUTHOR("Kyle Roeschley "); MODULE_LICENSE("GPL"); RCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'tools/perf/util/dwarf-aux.h')