| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Corey Minyard | 4414 | 91.96% | 28 | 43.75% |
| Rusty Russell | 75 | 1.56% | 1 | 1.56% |
| Arnd Bergmann | 64 | 1.33% | 4 | 6.25% |
| Andrew Morton | 38 | 0.79% | 1 | 1.56% |
| Don Zickus | 31 | 0.65% | 1 | 1.56% |
| Al Viro | 27 | 0.56% | 4 | 6.25% |
| Randy Dunlap | 27 | 0.56% | 1 | 1.56% |
| Jean-Yves Faye | 22 | 0.46% | 1 | 1.56% |
| Arkadiusz Miskiewicz | 21 | 0.44% | 1 | 1.56% |
| Sébastien Dugué | 17 | 0.35% | 1 | 1.56% |
| Linus Torvalds | 11 | 0.23% | 4 | 6.25% |
| Joe Perches | 10 | 0.21% | 1 | 1.56% |
| Pekka J Enberg | 7 | 0.15% | 1 | 1.56% |
| Valentin Vidic | 7 | 0.15% | 1 | 1.56% |
| Robert Lippert | 4 | 0.08% | 1 | 1.56% |
| Ingo Molnar | 4 | 0.08% | 2 | 3.12% |
| Thomas Gleixner | 4 | 0.08% | 1 | 1.56% |
| Hidehiro Kawai | 3 | 0.06% | 1 | 1.56% |
| Christoph Hellwig | 3 | 0.06% | 1 | 1.56% |
| Luis R. Rodriguez | 3 | 0.06% | 1 | 1.56% |
| Wim Van Sebroeck | 2 | 0.04% | 1 | 1.56% |
| Wei Yongjun | 1 | 0.02% | 1 | 1.56% |
| Arjan van de Ven | 1 | 0.02% | 1 | 1.56% |
| Andrey Panin | 1 | 0.02% | 1 | 1.56% |
| Mark D Rustad | 1 | 0.02% | 1 | 1.56% |
| Xiongfeng Wang | 1 | 0.02% | 1 | 1.56% |
| Arun Sharma | 1 | 0.02% | 1 | 1.56% |
| Total | 4800 | 64 |
// SPDX-License-Identifier: GPL-2.0+ /* * ipmi_watchdog.c * * A watchdog timer based upon the IPMI interface. * * Author: MontaVista Software, Inc. * Corey Minyard <minyard@mvista.com> * source@mvista.com * * Copyright 2002 MontaVista Software Inc. */ #define pr_fmt(fmt) "IPMI Watchdog: " fmt #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/ipmi.h> #include <linux/ipmi_smi.h> #include <linux/mutex.h> #include <linux/watchdog.h> #include <linux/miscdevice.h> #include <linux/init.h> #include <linux/completion.h> #include <linux/kdebug.h> #include <linux/rwsem.h> #include <linux/errno.h> #include <linux/uaccess.h> #include <linux/notifier.h> #include <linux/nmi.h> #include <linux/reboot.h> #include <linux/wait.h> #include <linux/poll.h> #include <linux/string.h> #include <linux/ctype.h> #include <linux/delay.h> #include <linux/atomic.h> #include <linux/sched/signal.h> #ifdef CONFIG_X86 /* * This is ugly, but I've determined that x86 is the only architecture * that can reasonably support the IPMI NMI watchdog timeout at this * time. If another architecture adds this capability somehow, it * will have to be a somewhat different mechanism and I have no idea * how it will work. So in the unlikely event that another * architecture supports this, we can figure out a good generic * mechanism for it at that time. */ #include <asm/kdebug.h> #include <asm/nmi.h> #define HAVE_DIE_NMI #endif /* * The IPMI command/response information for the watchdog timer. */ /* values for byte 1 of the set command, byte 2 of the get response. */ #define WDOG_DONT_LOG (1 << 7) #define WDOG_DONT_STOP_ON_SET (1 << 6) #define WDOG_SET_TIMER_USE(byte, use) \ byte = ((byte) & 0xf8) | ((use) & 0x7) #define WDOG_GET_TIMER_USE(byte) ((byte) & 0x7) #define WDOG_TIMER_USE_BIOS_FRB2 1 #define WDOG_TIMER_USE_BIOS_POST 2 #define WDOG_TIMER_USE_OS_LOAD 3 #define WDOG_TIMER_USE_SMS_OS 4 #define WDOG_TIMER_USE_OEM 5 /* values for byte 2 of the set command, byte 3 of the get response. */ #define WDOG_SET_PRETIMEOUT_ACT(byte, use) \ byte = ((byte) & 0x8f) | (((use) & 0x7) << 4) #define WDOG_GET_PRETIMEOUT_ACT(byte) (((byte) >> 4) & 0x7) #define WDOG_PRETIMEOUT_NONE 0 #define WDOG_PRETIMEOUT_SMI 1 #define WDOG_PRETIMEOUT_NMI 2 #define WDOG_PRETIMEOUT_MSG_INT 3 /* Operations that can be performed on a pretimout. */ #define WDOG_PREOP_NONE 0 #define WDOG_PREOP_PANIC 1 /* Cause data to be available to read. Doesn't work in NMI mode. */ #define WDOG_PREOP_GIVE_DATA 2 /* Actions to perform on a full timeout. */ #define WDOG_SET_TIMEOUT_ACT(byte, use) \ byte = ((byte) & 0xf8) | ((use) & 0x7) #define WDOG_GET_TIMEOUT_ACT(byte) ((byte) & 0x7) #define WDOG_TIMEOUT_NONE 0 #define WDOG_TIMEOUT_RESET 1 #define WDOG_TIMEOUT_POWER_DOWN 2 #define WDOG_TIMEOUT_POWER_CYCLE 3 /* * Byte 3 of the get command, byte 4 of the get response is the * pre-timeout in seconds. */ /* Bits for setting byte 4 of the set command, byte 5 of the get response. */ #define WDOG_EXPIRE_CLEAR_BIOS_FRB2 (1 << 1) #define WDOG_EXPIRE_CLEAR_BIOS_POST (1 << 2) #define WDOG_EXPIRE_CLEAR_OS_LOAD (1 << 3) #define WDOG_EXPIRE_CLEAR_SMS_OS (1 << 4) #define WDOG_EXPIRE_CLEAR_OEM (1 << 5) /* * Setting/getting the watchdog timer value. This is for bytes 5 and * 6 (the timeout time) of the set command, and bytes 6 and 7 (the * timeout time) and 8 and 9 (the current countdown value) of the * response. The timeout value is given in seconds (in the command it * is 100ms intervals). */ #define WDOG_SET_TIMEOUT(byte1, byte2, val) \ (byte1) = (((val) * 10) & 0xff), (byte2) = (((val) * 10) >> 8) #define WDOG_GET_TIMEOUT(byte1, byte2) \ (((byte1) | ((byte2) << 8)) / 10) #define IPMI_WDOG_RESET_TIMER 0x22 #define IPMI_WDOG_SET_TIMER 0x24 #define IPMI_WDOG_GET_TIMER 0x25 #define IPMI_WDOG_TIMER_NOT_INIT_RESP 0x80 static DEFINE_MUTEX(ipmi_watchdog_mutex); static bool nowayout = WATCHDOG_NOWAYOUT; static struct ipmi_user *watchdog_user; static int watchdog_ifnum; /* Default the timeout to 10 seconds. */ static int timeout = 10; /* The pre-timeout is disabled by default. */ static int pretimeout; /* Default timeout to set on panic */ static int panic_wdt_timeout = 255; /* Default action is to reset the board on a timeout. */ static unsigned char action_val = WDOG_TIMEOUT_RESET; static char action[16] = "reset"; static unsigned char preaction_val = WDOG_PRETIMEOUT_NONE; static char preaction[16] = "pre_none"; static unsigned char preop_val = WDOG_PREOP_NONE; static char preop[16] = "preop_none"; static DEFINE_SPINLOCK(ipmi_read_lock); static char data_to_read; static DECLARE_WAIT_QUEUE_HEAD(read_q); static struct fasync_struct *fasync_q; static atomic_t pretimeout_since_last_heartbeat; static char expect_close; static int ifnum_to_use = -1; /* Parameters to ipmi_set_timeout */ #define IPMI_SET_TIMEOUT_NO_HB 0 #define IPMI_SET_TIMEOUT_HB_IF_NECESSARY 1 #define IPMI_SET_TIMEOUT_FORCE_HB 2 static int ipmi_set_timeout(int do_heartbeat); static void ipmi_register_watchdog(int ipmi_intf); static void ipmi_unregister_watchdog(int ipmi_intf); /* * If true, the driver will start running as soon as it is configured * and ready. */ static int start_now; static int set_param_timeout(const char *val, const struct kernel_param *kp) { char *endp; int l; int rv = 0; if (!val) return -EINVAL; l = simple_strtoul(val, &endp, 0); if (endp == val) return -EINVAL; *((int *)kp->arg) = l; if (watchdog_user) rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); return rv; } static const struct kernel_param_ops param_ops_timeout = { .set = set_param_timeout, .get = param_get_int, }; #define param_check_timeout param_check_int typedef int (*action_fn)(const char *intval, char *outval); static int action_op(const char *inval, char *outval); static int preaction_op(const char *inval, char *outval); static int preop_op(const char *inval, char *outval); static void check_parms(void); static int set_param_str(const char *val, const struct kernel_param *kp) { action_fn fn = (action_fn) kp->arg; int rv = 0; char valcp[16]; char *s; strncpy(valcp, val, 15); valcp[15] = '\0'; s = strstrip(valcp); rv = fn(s, NULL); if (rv) goto out; check_parms(); if (watchdog_user) rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); out: return rv; } static int get_param_str(char *buffer, const struct kernel_param *kp) { action_fn fn = (action_fn) kp->arg; int rv; rv = fn(NULL, buffer); if (rv) return rv; return strlen(buffer); } static int set_param_wdog_ifnum(const char *val, const struct kernel_param *kp) { int rv = param_set_int(val, kp); if (rv) return rv; if ((ifnum_to_use < 0) || (ifnum_to_use == watchdog_ifnum)) return 0; ipmi_unregister_watchdog(watchdog_ifnum); ipmi_register_watchdog(ifnum_to_use); return 0; } static const struct kernel_param_ops param_ops_wdog_ifnum = { .set = set_param_wdog_ifnum, .get = param_get_int, }; #define param_check_wdog_ifnum param_check_int static const struct kernel_param_ops param_ops_str = { .set = set_param_str, .get = get_param_str, }; module_param(ifnum_to_use, wdog_ifnum, 0644); MODULE_PARM_DESC(ifnum_to_use, "The interface number to use for the watchdog " "timer. Setting to -1 defaults to the first registered " "interface"); module_param(timeout, timeout, 0644); MODULE_PARM_DESC(timeout, "Timeout value in seconds."); module_param(pretimeout, timeout, 0644); MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds."); module_param(panic_wdt_timeout, timeout, 0644); MODULE_PARM_DESC(panic_wdt_timeout, "Timeout value on kernel panic in seconds."); module_param_cb(action, ¶m_ops_str, action_op, 0644); MODULE_PARM_DESC(action, "Timeout action. One of: " "reset, none, power_cycle, power_off."); module_param_cb(preaction, ¶m_ops_str, preaction_op, 0644); MODULE_PARM_DESC(preaction, "Pretimeout action. One of: " "pre_none, pre_smi, pre_nmi, pre_int."); module_param_cb(preop, ¶m_ops_str, preop_op, 0644); MODULE_PARM_DESC(preop, "Pretimeout driver operation. One of: " "preop_none, preop_panic, preop_give_data."); module_param(start_now, int, 0444); MODULE_PARM_DESC(start_now, "Set to 1 to start the watchdog as" "soon as the driver is loaded."); module_param(nowayout, bool, 0644); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " "(default=CONFIG_WATCHDOG_NOWAYOUT)"); /* Default state of the timer. */ static unsigned char ipmi_watchdog_state = WDOG_TIMEOUT_NONE; /* Is someone using the watchdog? Only one user is allowed. */ static unsigned long ipmi_wdog_open; /* * If set to 1, the heartbeat command will set the state to reset and * start the timer. The timer doesn't normally run when the driver is * first opened until the heartbeat is set the first time, this * variable is used to accomplish this. */ static int ipmi_start_timer_on_heartbeat; /* IPMI version of the BMC. */ static unsigned char ipmi_version_major; static unsigned char ipmi_version_minor; /* If a pretimeout occurs, this is used to allow only one panic to happen. */ static atomic_t preop_panic_excl = ATOMIC_INIT(-1); #ifdef HAVE_DIE_NMI static int testing_nmi; static int nmi_handler_registered; #endif static int __ipmi_heartbeat(void); /* * We use a mutex to make sure that only one thing can send a set a * message at one time. The mutex is claimed when a message is sent * and freed when both the send and receive messages are free. */ static atomic_t msg_tofree = ATOMIC_INIT(0); static DECLARE_COMPLETION(msg_wait); static void msg_free_smi(struct ipmi_smi_msg *msg) { if (atomic_dec_and_test(&msg_tofree)) complete(&msg_wait); } static void msg_free_recv(struct ipmi_recv_msg *msg) { if (atomic_dec_and_test(&msg_tofree)) complete(&msg_wait); } static struct ipmi_smi_msg smi_msg = { .done = msg_free_smi }; static struct ipmi_recv_msg recv_msg = { .done = msg_free_recv }; static int __ipmi_set_timeout(struct ipmi_smi_msg *smi_msg, struct ipmi_recv_msg *recv_msg, int *send_heartbeat_now) { struct kernel_ipmi_msg msg; unsigned char data[6]; int rv; struct ipmi_system_interface_addr addr; int hbnow = 0; data[0] = 0; WDOG_SET_TIMER_USE(data[0], WDOG_TIMER_USE_SMS_OS); if ((ipmi_version_major > 1) || ((ipmi_version_major == 1) && (ipmi_version_minor >= 5))) { /* This is an IPMI 1.5-only feature. */ data[0] |= WDOG_DONT_STOP_ON_SET; } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) { /* * In ipmi 1.0, setting the timer stops the watchdog, we * need to start it back up again. */ hbnow = 1; } data[1] = 0; WDOG_SET_TIMEOUT_ACT(data[1], ipmi_watchdog_state); if ((pretimeout > 0) && (ipmi_watchdog_state != WDOG_TIMEOUT_NONE)) { WDOG_SET_PRETIMEOUT_ACT(data[1], preaction_val); data[2] = pretimeout; } else { WDOG_SET_PRETIMEOUT_ACT(data[1], WDOG_PRETIMEOUT_NONE); data[2] = 0; /* No pretimeout. */ } data[3] = 0; WDOG_SET_TIMEOUT(data[4], data[5], timeout); addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; addr.channel = IPMI_BMC_CHANNEL; addr.lun = 0; msg.netfn = 0x06; msg.cmd = IPMI_WDOG_SET_TIMER; msg.data = data; msg.data_len = sizeof(data); rv = ipmi_request_supply_msgs(watchdog_user, (struct ipmi_addr *) &addr, 0, &msg, NULL, smi_msg, recv_msg, 1); if (rv) pr_warn("set timeout error: %d\n", rv); else if (send_heartbeat_now) *send_heartbeat_now = hbnow; return rv; } static int _ipmi_set_timeout(int do_heartbeat) { int send_heartbeat_now; int rv; if (!watchdog_user) return -ENODEV; atomic_set(&msg_tofree, 2); rv = __ipmi_set_timeout(&smi_msg, &recv_msg, &send_heartbeat_now); if (rv) return rv; wait_for_completion(&msg_wait); if ((do_heartbeat == IPMI_SET_TIMEOUT_FORCE_HB) || ((send_heartbeat_now) && (do_heartbeat == IPMI_SET_TIMEOUT_HB_IF_NECESSARY))) rv = __ipmi_heartbeat(); return rv; } static int ipmi_set_timeout(int do_heartbeat) { int rv; mutex_lock(&ipmi_watchdog_mutex); rv = _ipmi_set_timeout(do_heartbeat); mutex_unlock(&ipmi_watchdog_mutex); return rv; } static atomic_t panic_done_count = ATOMIC_INIT(0); static void panic_smi_free(struct ipmi_smi_msg *msg) { atomic_dec(&panic_done_count); } static void panic_recv_free(struct ipmi_recv_msg *msg) { atomic_dec(&panic_done_count); } static struct ipmi_smi_msg panic_halt_heartbeat_smi_msg = { .done = panic_smi_free }; static struct ipmi_recv_msg panic_halt_heartbeat_recv_msg = { .done = panic_recv_free }; static void panic_halt_ipmi_heartbeat(void) { struct kernel_ipmi_msg msg; struct ipmi_system_interface_addr addr; int rv; /* * Don't reset the timer if we have the timer turned off, that * re-enables the watchdog. */ if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) return; addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; addr.channel = IPMI_BMC_CHANNEL; addr.lun = 0; msg.netfn = 0x06; msg.cmd = IPMI_WDOG_RESET_TIMER; msg.data = NULL; msg.data_len = 0; atomic_add(1, &panic_done_count); rv = ipmi_request_supply_msgs(watchdog_user, (struct ipmi_addr *) &addr, 0, &msg, NULL, &panic_halt_heartbeat_smi_msg, &panic_halt_heartbeat_recv_msg, 1); if (rv) atomic_sub(1, &panic_done_count); } static struct ipmi_smi_msg panic_halt_smi_msg = { .done = panic_smi_free }; static struct ipmi_recv_msg panic_halt_recv_msg = { .done = panic_recv_free }; /* * Special call, doesn't claim any locks. This is only to be called * at panic or halt time, in run-to-completion mode, when the caller * is the only CPU and the only thing that will be going is these IPMI * calls. */ static void panic_halt_ipmi_set_timeout(void) { int send_heartbeat_now; int rv; /* Wait for the messages to be free. */ while (atomic_read(&panic_done_count) != 0) ipmi_poll_interface(watchdog_user); atomic_add(1, &panic_done_count); rv = __ipmi_set_timeout(&panic_halt_smi_msg, &panic_halt_recv_msg, &send_heartbeat_now); if (rv) { atomic_sub(1, &panic_done_count); pr_warn("Unable to extend the watchdog timeout\n"); } else { if (send_heartbeat_now) panic_halt_ipmi_heartbeat(); } while (atomic_read(&panic_done_count) != 0) ipmi_poll_interface(watchdog_user); } static int __ipmi_heartbeat(void) { struct kernel_ipmi_msg msg; int rv; struct ipmi_system_interface_addr addr; int timeout_retries = 0; restart: /* * Don't reset the timer if we have the timer turned off, that * re-enables the watchdog. */ if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) return 0; atomic_set(&msg_tofree, 2); addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; addr.channel = IPMI_BMC_CHANNEL; addr.lun = 0; msg.netfn = 0x06; msg.cmd = IPMI_WDOG_RESET_TIMER; msg.data = NULL; msg.data_len = 0; rv = ipmi_request_supply_msgs(watchdog_user, (struct ipmi_addr *) &addr, 0, &msg, NULL, &smi_msg, &recv_msg, 1); if (rv) { pr_warn("heartbeat send failure: %d\n", rv); return rv; } /* Wait for the heartbeat to be sent. */ wait_for_completion(&msg_wait); if (recv_msg.msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP) { timeout_retries++; if (timeout_retries > 3) { pr_err("Unable to restore the IPMI watchdog's settings, giving up\n"); rv = -EIO; goto out; } /* * The timer was not initialized, that means the BMC was * probably reset and lost the watchdog information. Attempt * to restore the timer's info. Note that we still hold * the heartbeat lock, to keep a heartbeat from happening * in this process, so must say no heartbeat to avoid a * deadlock on this mutex */ rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); if (rv) { pr_err("Unable to send the command to set the watchdog's settings, giving up\n"); goto out; } /* Might need a heartbeat send, go ahead and do it. */ goto restart; } else if (recv_msg.msg.data[0] != 0) { /* * Got an error in the heartbeat response. It was already * reported in ipmi_wdog_msg_handler, but we should return * an error here. */ rv = -EINVAL; } out: return rv; } static int _ipmi_heartbeat(void) { int rv; if (!watchdog_user) return -ENODEV; if (ipmi_start_timer_on_heartbeat) { ipmi_start_timer_on_heartbeat = 0; ipmi_watchdog_state = action_val; rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); } else if (atomic_cmpxchg(&pretimeout_since_last_heartbeat, 1, 0)) { /* * A pretimeout occurred, make sure we set the timeout. * We don't want to set the action, though, we want to * leave that alone (thus it can't be combined with the * above operation. */ rv = _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); } else { rv = __ipmi_heartbeat(); } return rv; } static int ipmi_heartbeat(void) { int rv; mutex_lock(&ipmi_watchdog_mutex); rv = _ipmi_heartbeat(); mutex_unlock(&ipmi_watchdog_mutex); return rv; } static struct watchdog_info ident = { .options = 0, /* WDIOF_SETTIMEOUT, */ .firmware_version = 1, .identity = "IPMI" }; static int ipmi_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { void __user *argp = (void __user *)arg; int i; int val; switch (cmd) { case WDIOC_GETSUPPORT: i = copy_to_user(argp, &ident, sizeof(ident)); return i ? -EFAULT : 0; case WDIOC_SETTIMEOUT: i = copy_from_user(&val, argp, sizeof(int)); if (i) return -EFAULT; timeout = val; return _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); case WDIOC_GETTIMEOUT: i = copy_to_user(argp, &timeout, sizeof(timeout)); if (i) return -EFAULT; return 0; case WDIOC_SETPRETIMEOUT: i = copy_from_user(&val, argp, sizeof(int)); if (i) return -EFAULT; pretimeout = val; return _ipmi_set_timeout(IPMI_SET_TIMEOUT_HB_IF_NECESSARY); case WDIOC_GETPRETIMEOUT: i = copy_to_user(argp, &pretimeout, sizeof(pretimeout)); if (i) return -EFAULT; return 0; case WDIOC_KEEPALIVE: return _ipmi_heartbeat(); case WDIOC_SETOPTIONS: i = copy_from_user(&val, argp, sizeof(int)); if (i) return -EFAULT; if (val & WDIOS_DISABLECARD) { ipmi_watchdog_state = WDOG_TIMEOUT_NONE; _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); ipmi_start_timer_on_heartbeat = 0; } if (val & WDIOS_ENABLECARD) { ipmi_watchdog_state = action_val; _ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); } return 0; case WDIOC_GETSTATUS: val = 0; i = copy_to_user(argp, &val, sizeof(val)); if (i) return -EFAULT; return 0; default: return -ENOIOCTLCMD; } } static long ipmi_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { int ret; mutex_lock(&ipmi_watchdog_mutex); ret = ipmi_ioctl(file, cmd, arg); mutex_unlock(&ipmi_watchdog_mutex); return ret; } static ssize_t ipmi_write(struct file *file, const char __user *buf, size_t len, loff_t *ppos) { int rv; if (len) { if (!nowayout) { size_t i; /* In case it was set long ago */ expect_close = 0; for (i = 0; i != len; i++) { char c; if (get_user(c, buf + i)) return -EFAULT; if (c == 'V') expect_close = 42; } } rv = ipmi_heartbeat(); if (rv) return rv; } return len; } static ssize_t ipmi_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { int rv = 0; wait_queue_entry_t wait; if (count <= 0) return 0; /* * Reading returns if the pretimeout has gone off, and it only does * it once per pretimeout. */ spin_lock_irq(&ipmi_read_lock); if (!data_to_read) { if (file->f_flags & O_NONBLOCK) { rv = -EAGAIN; goto out; } init_waitqueue_entry(&wait, current); add_wait_queue(&read_q, &wait); while (!data_to_read) { set_current_state(TASK_INTERRUPTIBLE); spin_unlock_irq(&ipmi_read_lock); schedule(); spin_lock_irq(&ipmi_read_lock); } remove_wait_queue(&read_q, &wait); if (signal_pending(current)) { rv = -ERESTARTSYS; goto out; } } data_to_read = 0; out: spin_unlock_irq(&ipmi_read_lock); if (rv == 0) { if (copy_to_user(buf, &data_to_read, 1)) rv = -EFAULT; else rv = 1; } return rv; } static int ipmi_open(struct inode *ino, struct file *filep) { switch (iminor(ino)) { case WATCHDOG_MINOR: if (test_and_set_bit(0, &ipmi_wdog_open)) return -EBUSY; /* * Don't start the timer now, let it start on the * first heartbeat. */ ipmi_start_timer_on_heartbeat = 1; return nonseekable_open(ino, filep); default: return (-ENODEV); } } static __poll_t ipmi_poll(struct file *file, poll_table *wait) { __poll_t mask = 0; poll_wait(file, &read_q, wait); spin_lock_irq(&ipmi_read_lock); if (data_to_read) mask |= (EPOLLIN | EPOLLRDNORM); spin_unlock_irq(&ipmi_read_lock); return mask; } static int ipmi_fasync(int fd, struct file *file, int on) { int result; result = fasync_helper(fd, file, on, &fasync_q); return (result); } static int ipmi_close(struct inode *ino, struct file *filep) { if (iminor(ino) == WATCHDOG_MINOR) { if (expect_close == 42) { mutex_lock(&ipmi_watchdog_mutex); ipmi_watchdog_state = WDOG_TIMEOUT_NONE; _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); mutex_unlock(&ipmi_watchdog_mutex); } else { pr_crit("Unexpected close, not stopping watchdog!\n"); ipmi_heartbeat(); } clear_bit(0, &ipmi_wdog_open); } expect_close = 0; return 0; } static const struct file_operations ipmi_wdog_fops = { .owner = THIS_MODULE, .read = ipmi_read, .poll = ipmi_poll, .write = ipmi_write, .unlocked_ioctl = ipmi_unlocked_ioctl, .open = ipmi_open, .release = ipmi_close, .fasync = ipmi_fasync, .llseek = no_llseek, }; static struct miscdevice ipmi_wdog_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &ipmi_wdog_fops }; static void ipmi_wdog_msg_handler(struct ipmi_recv_msg *msg, void *handler_data) { if (msg->msg.cmd == IPMI_WDOG_RESET_TIMER && msg->msg.data[0] == IPMI_WDOG_TIMER_NOT_INIT_RESP) pr_info("response: The IPMI controller appears to have been reset, will attempt to reinitialize the watchdog timer\n"); else if (msg->msg.data[0] != 0) pr_err("response: Error %x on cmd %x\n", msg->msg.data[0], msg->msg.cmd); ipmi_free_recv_msg(msg); } static void ipmi_wdog_pretimeout_handler(void *handler_data) { if (preaction_val != WDOG_PRETIMEOUT_NONE) { if (preop_val == WDOG_PREOP_PANIC) { if (atomic_inc_and_test(&preop_panic_excl)) panic("Watchdog pre-timeout"); } else if (preop_val == WDOG_PREOP_GIVE_DATA) { unsigned long flags; spin_lock_irqsave(&ipmi_read_lock, flags); data_to_read = 1; wake_up_interruptible(&read_q); kill_fasync(&fasync_q, SIGIO, POLL_IN); spin_unlock_irqrestore(&ipmi_read_lock, flags); } } /* * On some machines, the heartbeat will give an error and not * work unless we re-enable the timer. So do so. */ atomic_set(&pretimeout_since_last_heartbeat, 1); } static void ipmi_wdog_panic_handler(void *user_data) { static int panic_event_handled; /* * On a panic, if we have a panic timeout, make sure to extend * the watchdog timer to a reasonable value to complete the * panic, if the watchdog timer is running. Plus the * pretimeout is meaningless at panic time. */ if (watchdog_user && !panic_event_handled && ipmi_watchdog_state != WDOG_TIMEOUT_NONE) { /* Make sure we do this only once. */ panic_event_handled = 1; timeout = panic_wdt_timeout; pretimeout = 0; panic_halt_ipmi_set_timeout(); } } static const struct ipmi_user_hndl ipmi_hndlrs = { .ipmi_recv_hndl = ipmi_wdog_msg_handler, .ipmi_watchdog_pretimeout = ipmi_wdog_pretimeout_handler, .ipmi_panic_handler = ipmi_wdog_panic_handler }; static void ipmi_register_watchdog(int ipmi_intf) { int rv = -EBUSY; if (watchdog_user) goto out; if ((ifnum_to_use >= 0) && (ifnum_to_use != ipmi_intf)) goto out; watchdog_ifnum = ipmi_intf; rv = ipmi_create_user(ipmi_intf, &ipmi_hndlrs, NULL, &watchdog_user); if (rv < 0) { pr_crit("Unable to register with ipmi\n"); goto out; } rv = ipmi_get_version(watchdog_user, &ipmi_version_major, &ipmi_version_minor); if (rv) { pr_warn("Unable to get IPMI version, assuming 1.0\n"); ipmi_version_major = 1; ipmi_version_minor = 0; } rv = misc_register(&ipmi_wdog_miscdev); if (rv < 0) { ipmi_destroy_user(watchdog_user); watchdog_user = NULL; pr_crit("Unable to register misc device\n"); } #ifdef HAVE_DIE_NMI if (nmi_handler_registered) { int old_pretimeout = pretimeout; int old_timeout = timeout; int old_preop_val = preop_val; /* * Set the pretimeout to go off in a second and give * ourselves plenty of time to stop the timer. */ ipmi_watchdog_state = WDOG_TIMEOUT_RESET; preop_val = WDOG_PREOP_NONE; /* Make sure nothing happens */ pretimeout = 99; timeout = 100; testing_nmi = 1; rv = ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); if (rv) { pr_warn("Error starting timer to test NMI: 0x%x. The NMI pretimeout will likely not work\n", rv); rv = 0; goto out_restore; } msleep(1500); if (testing_nmi != 2) { pr_warn("IPMI NMI didn't seem to occur. The NMI pretimeout will likely not work\n"); } out_restore: testing_nmi = 0; preop_val = old_preop_val; pretimeout = old_pretimeout; timeout = old_timeout; } #endif out: if ((start_now) && (rv == 0)) { /* Run from startup, so start the timer now. */ start_now = 0; /* Disable this function after first startup. */ ipmi_watchdog_state = action_val; ipmi_set_timeout(IPMI_SET_TIMEOUT_FORCE_HB); pr_info("Starting now!\n"); } else { /* Stop the timer now. */ ipmi_watchdog_state = WDOG_TIMEOUT_NONE; ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); } } static void ipmi_unregister_watchdog(int ipmi_intf) { int rv; struct ipmi_user *loc_user = watchdog_user; if (!loc_user) return; if (watchdog_ifnum != ipmi_intf) return; /* Make sure no one can call us any more. */ misc_deregister(&ipmi_wdog_miscdev); watchdog_user = NULL; /* * Wait to make sure the message makes it out. The lower layer has * pointers to our buffers, we want to make sure they are done before * we release our memory. */ while (atomic_read(&msg_tofree)) msg_free_smi(NULL); mutex_lock(&ipmi_watchdog_mutex); /* Disconnect from IPMI. */ rv = ipmi_destroy_user(loc_user); if (rv) pr_warn("error unlinking from IPMI: %d\n", rv); /* If it comes back, restart it properly. */ ipmi_start_timer_on_heartbeat = 1; mutex_unlock(&ipmi_watchdog_mutex); } #ifdef HAVE_DIE_NMI static int ipmi_nmi(unsigned int val, struct pt_regs *regs) { /* * If we get here, it's an NMI that's not a memory or I/O * error. We can't truly tell if it's from IPMI or not * without sending a message, and sending a message is almost * impossible because of locking. */ if (testing_nmi) { testing_nmi = 2; return NMI_HANDLED; } /* If we are not expecting a timeout, ignore it. */ if (ipmi_watchdog_state == WDOG_TIMEOUT_NONE) return NMI_DONE; if (preaction_val != WDOG_PRETIMEOUT_NMI) return NMI_DONE; /* * If no one else handled the NMI, we assume it was the IPMI * watchdog. */ if (preop_val == WDOG_PREOP_PANIC) { /* On some machines, the heartbeat will give an error and not work unless we re-enable the timer. So do so. */ atomic_set(&pretimeout_since_last_heartbeat, 1); if (atomic_inc_and_test(&preop_panic_excl)) nmi_panic(regs, "pre-timeout"); } return NMI_HANDLED; } #endif static int wdog_reboot_handler(struct notifier_block *this, unsigned long code, void *unused) { static int reboot_event_handled; if ((watchdog_user) && (!reboot_event_handled)) { /* Make sure we only do this once. */ reboot_event_handled = 1; if (code == SYS_POWER_OFF || code == SYS_HALT) { /* Disable the WDT if we are shutting down. */ ipmi_watchdog_state = WDOG_TIMEOUT_NONE; ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); } else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) { /* Set a long timer to let the reboot happen or reset if it hangs, but only if the watchdog timer was already running. */ if (timeout < 120) timeout = 120; pretimeout = 0; ipmi_watchdog_state = WDOG_TIMEOUT_RESET; ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB); } } return NOTIFY_OK; } static struct notifier_block wdog_reboot_notifier = { .notifier_call = wdog_reboot_handler, .next = NULL, .priority = 0 }; static void ipmi_new_smi(int if_num, struct device *device) { ipmi_register_watchdog(if_num); } static void ipmi_smi_gone(int if_num) { ipmi_unregister_watchdog(if_num); } static struct ipmi_smi_watcher smi_watcher = { .owner = THIS_MODULE, .new_smi = ipmi_new_smi, .smi_gone = ipmi_smi_gone }; static int action_op(const char *inval, char *outval) { if (outval) strcpy(outval, action); if (!inval) return 0; if (strcmp(inval, "reset") == 0) action_val = WDOG_TIMEOUT_RESET; else if (strcmp(inval, "none") == 0) action_val = WDOG_TIMEOUT_NONE; else if (strcmp(inval, "power_cycle") == 0) action_val = WDOG_TIMEOUT_POWER_CYCLE; else if (strcmp(inval, "power_off") == 0) action_val = WDOG_TIMEOUT_POWER_DOWN; else return -EINVAL; strcpy(action, inval); return 0; } static int preaction_op(const char *inval, char *outval) { if (outval) strcpy(outval, preaction); if (!inval) return 0; if (strcmp(inval, "pre_none") == 0) preaction_val = WDOG_PRETIMEOUT_NONE; else if (strcmp(inval, "pre_smi") == 0) preaction_val = WDOG_PRETIMEOUT_SMI; #ifdef HAVE_DIE_NMI else if (strcmp(inval, "pre_nmi") == 0) preaction_val = WDOG_PRETIMEOUT_NMI; #endif else if (strcmp(inval, "pre_int") == 0) preaction_val = WDOG_PRETIMEOUT_MSG_INT; else return -EINVAL; strcpy(preaction, inval); return 0; } static int preop_op(const char *inval, char *outval) { if (outval) strcpy(outval, preop); if (!inval) return 0; if (strcmp(inval, "preop_none") == 0) preop_val = WDOG_PREOP_NONE; else if (strcmp(inval, "preop_panic") == 0) preop_val = WDOG_PREOP_PANIC; else if (strcmp(inval, "preop_give_data") == 0) preop_val = WDOG_PREOP_GIVE_DATA; else return -EINVAL; strcpy(preop, inval); return 0; } static void check_parms(void) { #ifdef HAVE_DIE_NMI int do_nmi = 0; int rv; if (preaction_val == WDOG_PRETIMEOUT_NMI) { do_nmi = 1; if (preop_val == WDOG_PREOP_GIVE_DATA) { pr_warn("Pretimeout op is to give data but NMI pretimeout is enabled, setting pretimeout op to none\n"); preop_op("preop_none", NULL); do_nmi = 0; } } if (do_nmi && !nmi_handler_registered) { rv = register_nmi_handler(NMI_UNKNOWN, ipmi_nmi, 0, "ipmi"); if (rv) { pr_warn("Can't register nmi handler\n"); return; } else nmi_handler_registered = 1; } else if (!do_nmi && nmi_handler_registered) { unregister_nmi_handler(NMI_UNKNOWN, "ipmi"); nmi_handler_registered = 0; } #endif } static int __init ipmi_wdog_init(void) { int rv; if (action_op(action, NULL)) { action_op("reset", NULL); pr_info("Unknown action '%s', defaulting to reset\n", action); } if (preaction_op(preaction, NULL)) { preaction_op("pre_none", NULL); pr_info("Unknown preaction '%s', defaulting to none\n", preaction); } if (preop_op(preop, NULL)) { preop_op("preop_none", NULL); pr_info("Unknown preop '%s', defaulting to none\n", preop); } check_parms(); register_reboot_notifier(&wdog_reboot_notifier); rv = ipmi_smi_watcher_register(&smi_watcher); if (rv) { #ifdef HAVE_DIE_NMI if (nmi_handler_registered) unregister_nmi_handler(NMI_UNKNOWN, "ipmi"); #endif unregister_reboot_notifier(&wdog_reboot_notifier); pr_warn("can't register smi watcher\n"); return rv; } pr_info("driver initialized\n"); return 0; } static void __exit ipmi_wdog_exit(void) { ipmi_smi_watcher_unregister(&smi_watcher); ipmi_unregister_watchdog(watchdog_ifnum); #ifdef HAVE_DIE_NMI if (nmi_handler_registered) unregister_nmi_handler(NMI_UNKNOWN, "ipmi"); #endif unregister_reboot_notifier(&wdog_reboot_notifier); } module_exit(ipmi_wdog_exit); module_init(ipmi_wdog_init); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>"); MODULE_DESCRIPTION("watchdog timer based upon the IPMI interface.");
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