/***************************************************************************** 函数名称 : mlog_print 功能描述 : 输入参数 : 输出参数 : 返 回 值 : No 修改历史 : *****************************************************************************/ asmlinkage void mlog_print(char *module, mlog_lv_eum loglv,const char *fmt,...) { int printed_len = 0; unsigned long flags; char *p ; unsigned wake_up = 0; va_list args; struct timespec uptime; if((NULL == module) || ( NULL == fmt)) { return; } /*PROC未创建成功,返回*/ if(FALSE == proc_init_ok) { return; } local_irq_save(flags); if (!raw_spin_trylock(&mlog_log_buf_lock)) { local_irq_restore(flags); return; } do_posix_clock_monotonic_gettime(&uptime); monotonic_to_bootbased(&uptime); snprintf(print_buf, MLOG_MAX_HEAD_LEN , "[%011lu][%s][%s]:", ((uptime.tv_sec * 1000) + (uptime.tv_nsec / 1000000)),/*将秒和纳秒转换成毫秒*/ module,mlog_get_log_lv_string(loglv)); printed_len = strlen(print_buf); va_start(args, fmt); vsnprintf(print_buf + printed_len , MLOG_MAX_LOG_LEN - 1, fmt, args); printed_len = strlen(print_buf); va_end(args); //若调用者log行尾未未增加换行,帮其增加 if('\n' != print_buf[printed_len - 1]) { print_buf[printed_len] = '\n'; printed_len++; print_buf[printed_len] = '\0'; } printed_len++; p = print_buf; for (; *p; p++) { mlog_log_write_char(*p); } wake_up = (log_wr_off == log_rd_off); if (!wake_up) { wake_up_interruptible(&mlog_log_wait); } raw_spin_unlock(&mlog_log_buf_lock); local_irq_restore(flags); return; }
/* Check if this is a system NMI event */ static int uv_check_nmi(struct uv_hub_nmi_s *hub_nmi) { int cpu = smp_processor_id(); int nmi = 0; local64_inc(&uv_nmi_count); uv_cpu_nmi.queries++; do { nmi = atomic_read(&hub_nmi->in_nmi); if (nmi) break; if (raw_spin_trylock(&hub_nmi->nmi_lock)) { /* check hub MMR NMI flag */ if (uv_nmi_test_mmr(hub_nmi)) { uv_set_in_nmi(cpu, hub_nmi); nmi = 1; break; } /* MMR NMI flag is clear */ raw_spin_unlock(&hub_nmi->nmi_lock); } else { /* wait a moment for the hub nmi locker to set flag */ cpu_relax(); udelay(uv_nmi_slave_delay); /* re-check hub in_nmi flag */ nmi = atomic_read(&hub_nmi->in_nmi); if (nmi) break; } /* check if this BMC missed setting the MMR NMI flag */ if (!nmi) { nmi = atomic_read(&uv_in_nmi); if (nmi) uv_set_in_nmi(cpu, hub_nmi); } } while (0); if (!nmi) local64_inc(&uv_nmi_misses); return nmi; }
/* * Adjust the priority chain. Also used for deadlock detection. * Decreases task's usage by one - may thus free the task. * Returns 0 or -EDEADLK. */ static int rt_mutex_adjust_prio_chain(struct task_struct *task, int deadlock_detect, struct rt_mutex *orig_lock, struct rt_mutex_waiter *orig_waiter, struct task_struct *top_task) { struct rt_mutex *lock; struct rt_mutex_waiter *waiter, *top_waiter = orig_waiter; int detect_deadlock, ret = 0, depth = 0; unsigned long flags; detect_deadlock = debug_rt_mutex_detect_deadlock(orig_waiter, deadlock_detect); /* * The (de)boosting is a step by step approach with a lot of * pitfalls. We want this to be preemptible and we want hold a * maximum of two locks per step. So we have to check * carefully whether things change under us. */ again: if (++depth > max_lock_depth) { static int prev_max; /* * Print this only once. If the admin changes the limit, * print a new message when reaching the limit again. */ if (prev_max != max_lock_depth) { prev_max = max_lock_depth; printk(KERN_WARNING "Maximum lock depth %d reached " "task: %s (%d)\n", max_lock_depth, top_task->comm, task_pid_nr(top_task)); } put_task_struct(task); return deadlock_detect ? -EDEADLK : 0; } retry: /* * Task can not go away as we did a get_task() before ! */ raw_spin_lock_irqsave(&task->pi_lock, flags); waiter = task->pi_blocked_on; /* * Check whether the end of the boosting chain has been * reached or the state of the chain has changed while we * dropped the locks. */ if (!waiter) goto out_unlock_pi; /* * Check the orig_waiter state. After we dropped the locks, * the previous owner of the lock might have released the lock. */ if (orig_waiter && !rt_mutex_owner(orig_lock)) goto out_unlock_pi; /* * Drop out, when the task has no waiters. Note, * top_waiter can be NULL, when we are in the deboosting * mode! */ if (top_waiter && (!task_has_pi_waiters(task) || top_waiter != task_top_pi_waiter(task))) goto out_unlock_pi; /* * When deadlock detection is off then we check, if further * priority adjustment is necessary. */ if (!detect_deadlock && waiter->list_entry.prio == task->prio) goto out_unlock_pi; lock = waiter->lock; if (!raw_spin_trylock(&lock->wait_lock)) { raw_spin_unlock_irqrestore(&task->pi_lock, flags); cpu_relax(); goto retry; } /* Deadlock detection */ if (lock == orig_lock || rt_mutex_owner(lock) == top_task) { debug_rt_mutex_deadlock(deadlock_detect, orig_waiter, lock); raw_spin_unlock(&lock->wait_lock); ret = deadlock_detect ? -EDEADLK : 0; goto out_unlock_pi; } top_waiter = rt_mutex_top_waiter(lock); /* Requeue the waiter */ plist_del(&waiter->list_entry, &lock->wait_list); waiter->list_entry.prio = task->prio; plist_add(&waiter->list_entry, &lock->wait_list); /* Release the task */ raw_spin_unlock_irqrestore(&task->pi_lock, flags); if (!rt_mutex_owner(lock)) { /* * If the requeue above changed the top waiter, then we need * to wake the new top waiter up to try to get the lock. */ if (top_waiter != rt_mutex_top_waiter(lock)) wake_up_process(rt_mutex_top_waiter(lock)->task); raw_spin_unlock(&lock->wait_lock); goto out_put_task; } put_task_struct(task); /* Grab the next task */ task = rt_mutex_owner(lock); get_task_struct(task); raw_spin_lock_irqsave(&task->pi_lock, flags); if (waiter == rt_mutex_top_waiter(lock)) { /* Boost the owner */ plist_del(&top_waiter->pi_list_entry, &task->pi_waiters); waiter->pi_list_entry.prio = waiter->list_entry.prio; plist_add(&waiter->pi_list_entry, &task->pi_waiters); __rt_mutex_adjust_prio(task); } else if (top_waiter == waiter) { /* Deboost the owner */ plist_del(&waiter->pi_list_entry, &task->pi_waiters); waiter = rt_mutex_top_waiter(lock); waiter->pi_list_entry.prio = waiter->list_entry.prio; plist_add(&waiter->pi_list_entry, &task->pi_waiters); __rt_mutex_adjust_prio(task); } raw_spin_unlock_irqrestore(&task->pi_lock, flags); top_waiter = rt_mutex_top_waiter(lock); raw_spin_unlock(&lock->wait_lock); if (!detect_deadlock && waiter != top_waiter) goto out_put_task; goto again; out_unlock_pi: raw_spin_unlock_irqrestore(&task->pi_lock, flags); out_put_task: put_task_struct(task); return ret; }
static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs, int exception_state) { unsigned long flags; int sstep_tries = 100; int error; int cpu; int trace_on = 0; int online_cpus = num_online_cpus(); #ifdef CONFIG_KGDB_KDB if (force_panic) /* Force panic in previous KDB, so skip this time */ return NOTIFY_DONE; #endif kgdb_info[ks->cpu].enter_kgdb++; kgdb_info[ks->cpu].exception_state |= exception_state; if (exception_state == DCPU_WANT_MASTER) atomic_inc(&masters_in_kgdb); else atomic_inc(&slaves_in_kgdb); if (arch_kgdb_ops.disable_hw_break) arch_kgdb_ops.disable_hw_break(regs); acquirelock: /* * Interrupts will be restored by the 'trap return' code, except when * single stepping. */ local_irq_save(flags); cpu = ks->cpu; kgdb_info[cpu].debuggerinfo = regs; kgdb_info[cpu].task = current; kgdb_info[cpu].ret_state = 0; kgdb_info[cpu].irq_depth = hardirq_count() >> HARDIRQ_SHIFT; /* Make sure the above info reaches the primary CPU */ smp_mb(); if (exception_level == 1) { if (raw_spin_trylock(&dbg_master_lock)) atomic_xchg(&kgdb_active, cpu); goto cpu_master_loop; } /* * CPU will loop if it is a slave or request to become a kgdb * master cpu and acquire the kgdb_active lock: */ while (1) { cpu_loop: if (kgdb_info[cpu].exception_state & DCPU_NEXT_MASTER) { kgdb_info[cpu].exception_state &= ~DCPU_NEXT_MASTER; goto cpu_master_loop; } else if (kgdb_info[cpu].exception_state & DCPU_WANT_MASTER) { if (raw_spin_trylock(&dbg_master_lock)) { atomic_xchg(&kgdb_active, cpu); break; } } else if (kgdb_info[cpu].exception_state & DCPU_IS_SLAVE) { if (!raw_spin_is_locked(&dbg_slave_lock)) goto return_normal; } else { return_normal: /* Return to normal operation by executing any * hw breakpoint fixup. */ if (arch_kgdb_ops.correct_hw_break) arch_kgdb_ops.correct_hw_break(); if (trace_on) tracing_on(); kgdb_info[cpu].exception_state &= ~(DCPU_WANT_MASTER | DCPU_IS_SLAVE); kgdb_info[cpu].enter_kgdb--; smp_mb__before_atomic_dec(); atomic_dec(&slaves_in_kgdb); dbg_touch_watchdogs(); local_irq_restore(flags); return 0; } cpu_relax(); } /* * For single stepping, try to only enter on the processor * that was single stepping. To guard against a deadlock, the * kernel will only try for the value of sstep_tries before * giving up and continuing on. */ if (atomic_read(&kgdb_cpu_doing_single_step) != -1 && (kgdb_info[cpu].task && kgdb_info[cpu].task->pid != kgdb_sstep_pid) && --sstep_tries) { atomic_set(&kgdb_active, -1); raw_spin_unlock(&dbg_master_lock); dbg_touch_watchdogs(); local_irq_restore(flags); goto acquirelock; } if (!kgdb_io_ready(1)) { kgdb_info[cpu].ret_state = 1; goto kgdb_restore; /* No I/O connection, resume the system */ } /* * Don't enter if we have hit a removed breakpoint. */ if (kgdb_skipexception(ks->ex_vector, ks->linux_regs)) goto kgdb_restore; /* Call the I/O driver's pre_exception routine */ if (dbg_io_ops->pre_exception) dbg_io_ops->pre_exception(); /* * Get the passive CPU lock which will hold all the non-primary * CPU in a spin state while the debugger is active */ if (!kgdb_single_step) raw_spin_lock(&dbg_slave_lock); #ifdef CONFIG_SMP /* Signal the other CPUs to enter kgdb_wait() */ if ((!kgdb_single_step) && kgdb_do_roundup) kgdb_roundup_cpus(flags); #endif /* * Wait for the other CPUs to be notified and be waiting for us: */ while (kgdb_do_roundup && (atomic_read(&masters_in_kgdb) + atomic_read(&slaves_in_kgdb)) != online_cpus) cpu_relax(); /* * At this point the primary processor is completely * in the debugger and all secondary CPUs are quiescent */ dbg_deactivate_sw_breakpoints(); kgdb_single_step = 0; kgdb_contthread = current; exception_level = 0; trace_on = tracing_is_on(); if (trace_on) tracing_off(); while (1) { cpu_master_loop: if (dbg_kdb_mode) { kgdb_connected = 1; error = kdb_stub(ks); if (error == -1) continue; kgdb_connected = 0; } else { error = gdb_serial_stub(ks); } if (error == DBG_PASS_EVENT) { dbg_kdb_mode = !dbg_kdb_mode; } else if (error == DBG_SWITCH_CPU_EVENT) { kgdb_info[dbg_switch_cpu].exception_state |= DCPU_NEXT_MASTER; goto cpu_loop; } else { kgdb_info[cpu].ret_state = error; break; } } /* Call the I/O driver's post_exception routine */ if (dbg_io_ops->post_exception) dbg_io_ops->post_exception(); if (!kgdb_single_step) { raw_spin_unlock(&dbg_slave_lock); /* Wait till all the CPUs have quit from the debugger. */ while (kgdb_do_roundup && atomic_read(&slaves_in_kgdb)) cpu_relax(); } kgdb_restore: if (atomic_read(&kgdb_cpu_doing_single_step) != -1) { int sstep_cpu = atomic_read(&kgdb_cpu_doing_single_step); if (kgdb_info[sstep_cpu].task) kgdb_sstep_pid = kgdb_info[sstep_cpu].task->pid; else kgdb_sstep_pid = 0; } if (arch_kgdb_ops.correct_hw_break) arch_kgdb_ops.correct_hw_break(); if (trace_on) tracing_on(); kgdb_info[cpu].exception_state &= ~(DCPU_WANT_MASTER | DCPU_IS_SLAVE); kgdb_info[cpu].enter_kgdb--; smp_mb__before_atomic_dec(); atomic_dec(&masters_in_kgdb); /* Free kgdb_active */ atomic_set(&kgdb_active, -1); raw_spin_unlock(&dbg_master_lock); dbg_touch_watchdogs(); local_irq_restore(flags); #ifdef CONFIG_KGDB_KDB /* If no user input, force trigger kernel panic here */ if (force_panic) { printk("KDB : Force Kernal Panic ! \n"); do { *(volatile int *)0 = 0; } while (1); } #endif return kgdb_info[cpu].ret_state; }