| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Infrastructure for profiling code inserted by 'gcc -pg'. |
| * |
| * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> |
| * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> |
| * |
| * Originally ported from the -rt patch by: |
| * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> |
| * |
| * Based on code in the latency_tracer, that is: |
| * |
| * Copyright (C) 2004-2006 Ingo Molnar |
| * Copyright (C) 2004 Nadia Yvette Chambers |
| */ |
| |
| #include <linux/stop_machine.h> |
| #include <linux/clocksource.h> |
| #include <linux/sched/task.h> |
| #include <linux/kallsyms.h> |
| #include <linux/seq_file.h> |
| #include <linux/tracefs.h> |
| #include <linux/hardirq.h> |
| #include <linux/kthread.h> |
| #include <linux/uaccess.h> |
| #include <linux/bsearch.h> |
| #include <linux/module.h> |
| #include <linux/ftrace.h> |
| #include <linux/sysctl.h> |
| #include <linux/slab.h> |
| #include <linux/ctype.h> |
| #include <linux/sort.h> |
| #include <linux/list.h> |
| #include <linux/hash.h> |
| #include <linux/rcupdate.h> |
| #include <linux/kprobes.h> |
| |
| #include <trace/events/sched.h> |
| |
| #include <asm/sections.h> |
| #include <asm/setup.h> |
| |
| #include "ftrace_internal.h" |
| #include "trace_output.h" |
| #include "trace_stat.h" |
| |
| #define FTRACE_WARN_ON(cond) \ |
| ({ \ |
| int ___r = cond; \ |
| if (WARN_ON(___r)) \ |
| ftrace_kill(); \ |
| ___r; \ |
| }) |
| |
| #define FTRACE_WARN_ON_ONCE(cond) \ |
| ({ \ |
| int ___r = cond; \ |
| if (WARN_ON_ONCE(___r)) \ |
| ftrace_kill(); \ |
| ___r; \ |
| }) |
| |
| /* hash bits for specific function selection */ |
| #define FTRACE_HASH_BITS 7 |
| #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) |
| #define FTRACE_HASH_DEFAULT_BITS 10 |
| #define FTRACE_HASH_MAX_BITS 12 |
| |
| #ifdef CONFIG_DYNAMIC_FTRACE |
| #define INIT_OPS_HASH(opsname) \ |
| .func_hash = &opsname.local_hash, \ |
| .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), |
| #define ASSIGN_OPS_HASH(opsname, val) \ |
| .func_hash = val, \ |
| .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), |
| #else |
| #define INIT_OPS_HASH(opsname) |
| #define ASSIGN_OPS_HASH(opsname, val) |
| #endif |
| |
| enum { |
| FTRACE_MODIFY_ENABLE_FL = (1 << 0), |
| FTRACE_MODIFY_MAY_SLEEP_FL = (1 << 1), |
| }; |
| |
| struct ftrace_ops ftrace_list_end __read_mostly = { |
| .func = ftrace_stub, |
| .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB, |
| INIT_OPS_HASH(ftrace_list_end) |
| }; |
| |
| /* ftrace_enabled is a method to turn ftrace on or off */ |
| int ftrace_enabled __read_mostly; |
| static int last_ftrace_enabled; |
| |
| /* Current function tracing op */ |
| struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; |
| /* What to set function_trace_op to */ |
| static struct ftrace_ops *set_function_trace_op; |
| |
| static bool ftrace_pids_enabled(struct ftrace_ops *ops) |
| { |
| struct trace_array *tr; |
| |
| if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private) |
| return false; |
| |
| tr = ops->private; |
| |
| return tr->function_pids != NULL; |
| } |
| |
| static void ftrace_update_trampoline(struct ftrace_ops *ops); |
| |
| /* |
| * ftrace_disabled is set when an anomaly is discovered. |
| * ftrace_disabled is much stronger than ftrace_enabled. |
| */ |
| static int ftrace_disabled __read_mostly; |
| |
| DEFINE_MUTEX(ftrace_lock); |
| |
| struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end; |
| ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
| struct ftrace_ops global_ops; |
| |
| #if ARCH_SUPPORTS_FTRACE_OPS |
| static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
| struct ftrace_ops *op, struct pt_regs *regs); |
| #else |
| /* See comment below, where ftrace_ops_list_func is defined */ |
| static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); |
| #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) |
| #endif |
| |
| static inline void ftrace_ops_init(struct ftrace_ops *ops) |
| { |
| #ifdef CONFIG_DYNAMIC_FTRACE |
| if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { |
| mutex_init(&ops->local_hash.regex_lock); |
| ops->func_hash = &ops->local_hash; |
| ops->flags |= FTRACE_OPS_FL_INITIALIZED; |
| } |
| #endif |
| } |
| |
| static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
| struct ftrace_ops *op, struct pt_regs *regs) |
| { |
| struct trace_array *tr = op->private; |
| |
| if (tr && this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid)) |
| return; |
| |
| op->saved_func(ip, parent_ip, op, regs); |
| } |
| |
| static void ftrace_sync(struct work_struct *work) |
| { |
| /* |
| * This function is just a stub to implement a hard force |
| * of synchronize_rcu(). This requires synchronizing |
| * tasks even in userspace and idle. |
| * |
| * Yes, function tracing is rude. |
| */ |
| } |
| |
| static void ftrace_sync_ipi(void *data) |
| { |
| /* Probably not needed, but do it anyway */ |
| smp_rmb(); |
| } |
| |
| static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops) |
| { |
| /* |
| * If this is a dynamic, RCU, or per CPU ops, or we force list func, |
| * then it needs to call the list anyway. |
| */ |
| if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) || |
| FTRACE_FORCE_LIST_FUNC) |
| return ftrace_ops_list_func; |
| |
| return ftrace_ops_get_func(ops); |
| } |
| |
| static void update_ftrace_function(void) |
| { |
| ftrace_func_t func; |
| |
| /* |
| * Prepare the ftrace_ops that the arch callback will use. |
| * If there's only one ftrace_ops registered, the ftrace_ops_list |
| * will point to the ops we want. |
| */ |
| set_function_trace_op = rcu_dereference_protected(ftrace_ops_list, |
| lockdep_is_held(&ftrace_lock)); |
| |
| /* If there's no ftrace_ops registered, just call the stub function */ |
| if (set_function_trace_op == &ftrace_list_end) { |
| func = ftrace_stub; |
| |
| /* |
| * If we are at the end of the list and this ops is |
| * recursion safe and not dynamic and the arch supports passing ops, |
| * then have the mcount trampoline call the function directly. |
| */ |
| } else if (rcu_dereference_protected(ftrace_ops_list->next, |
| lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { |
| func = ftrace_ops_get_list_func(ftrace_ops_list); |
| |
| } else { |
| /* Just use the default ftrace_ops */ |
| set_function_trace_op = &ftrace_list_end; |
| func = ftrace_ops_list_func; |
| } |
| |
| update_function_graph_func(); |
| |
| /* If there's no change, then do nothing more here */ |
| if (ftrace_trace_function == func) |
| return; |
| |
| /* |
| * If we are using the list function, it doesn't care |
| * about the function_trace_ops. |
| */ |
| if (func == ftrace_ops_list_func) { |
| ftrace_trace_function = func; |
| /* |
| * Don't even bother setting function_trace_ops, |
| * it would be racy to do so anyway. |
| */ |
| return; |
| } |
| |
| #ifndef CONFIG_DYNAMIC_FTRACE |
| /* |
| * For static tracing, we need to be a bit more careful. |
| * The function change takes affect immediately. Thus, |
| * we need to coorditate the setting of the function_trace_ops |
| * with the setting of the ftrace_trace_function. |
| * |
| * Set the function to the list ops, which will call the |
| * function we want, albeit indirectly, but it handles the |
| * ftrace_ops and doesn't depend on function_trace_op. |
| */ |
| ftrace_trace_function = ftrace_ops_list_func; |
| /* |
| * Make sure all CPUs see this. Yes this is slow, but static |
| * tracing is slow and nasty to have enabled. |
| */ |
| schedule_on_each_cpu(ftrace_sync); |
| /* Now all cpus are using the list ops. */ |
| function_trace_op = set_function_trace_op; |
| /* Make sure the function_trace_op is visible on all CPUs */ |
| smp_wmb(); |
| /* Nasty way to force a rmb on all cpus */ |
| smp_call_function(ftrace_sync_ipi, NULL, 1); |
| /* OK, we are all set to update the ftrace_trace_function now! */ |
| #endif /* !CONFIG_DYNAMIC_FTRACE */ |
| |
| ftrace_trace_function = func; |
| } |
| |
| static void add_ftrace_ops(struct ftrace_ops __rcu **list, |
| struct ftrace_ops *ops) |
| { |
| rcu_assign_pointer(ops->next, *list); |
| |
| /* |
| * We are entering ops into the list but another |
| * CPU might be walking that list. We need to make sure |
| * the ops->next pointer is valid before another CPU sees |
| * the ops pointer included into the list. |
| */ |
| rcu_assign_pointer(*list, ops); |
| } |
| |
| static int remove_ftrace_ops(struct ftrace_ops __rcu **list, |
| struct ftrace_ops *ops) |
| { |
| struct ftrace_ops **p; |
| |
| /* |
| * If we are removing the last function, then simply point |
| * to the ftrace_stub. |
| */ |
| if (rcu_dereference_protected(*list, |
| lockdep_is_held(&ftrace_lock)) == ops && |
| rcu_dereference_protected(ops->next, |
| lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { |
| *list = &ftrace_list_end; |
| return 0; |
| } |
| |
| for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
| if (*p == ops) |
| break; |
| |
| if (*p != ops) |
| return -1; |
| |
| *p = (*p)->next; |
| return 0; |
| } |
| |
| static void ftrace_update_trampoline(struct ftrace_ops *ops); |
| |
| int __register_ftrace_function(struct ftrace_ops *ops) |
| { |
| if (ops->flags & FTRACE_OPS_FL_DELETED) |
| return -EINVAL; |
| |
| if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
| return -EBUSY; |
| |
| #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
| /* |
| * If the ftrace_ops specifies SAVE_REGS, then it only can be used |
| * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. |
| * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. |
| */ |
| if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && |
| !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) |
| return -EINVAL; |
| |
| if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) |
| ops->flags |= FTRACE_OPS_FL_SAVE_REGS; |
| #endif |
| |
| if (!core_kernel_data((unsigned long)ops)) |
| ops->flags |= FTRACE_OPS_FL_DYNAMIC; |
| |
| add_ftrace_ops(&ftrace_ops_list, ops); |
| |
| /* Always save the function, and reset at unregistering */ |
| ops->saved_func = ops->func; |
| |
| if (ftrace_pids_enabled(ops)) |
| ops->func = ftrace_pid_func; |
| |
| ftrace_update_trampoline(ops); |
| |
| if (ftrace_enabled) |
| update_ftrace_function(); |
| |
| return 0; |
| } |
| |
| int __unregister_ftrace_function(struct ftrace_ops *ops) |
| { |
| int ret; |
| |
| if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
| return -EBUSY; |
| |
| ret = remove_ftrace_ops(&ftrace_ops_list, ops); |
| |
| if (ret < 0) |
| return ret; |
| |
| if (ftrace_enabled) |
| update_ftrace_function(); |
| |
| ops->func = ops->saved_func; |
| |
| return 0; |
| } |
| |
| static void ftrace_update_pid_func(void) |
| { |
| struct ftrace_ops *op; |
| |
| /* Only do something if we are tracing something */ |
| if (ftrace_trace_function == ftrace_stub) |
| return; |
| |
| do_for_each_ftrace_op(op, ftrace_ops_list) { |
| if (op->flags & FTRACE_OPS_FL_PID) { |
| op->func = ftrace_pids_enabled(op) ? |
| ftrace_pid_func : op->saved_func; |
| ftrace_update_trampoline(op); |
| } |
| } while_for_each_ftrace_op(op); |
| |
| update_ftrace_function(); |
| } |
| |
| #ifdef CONFIG_FUNCTION_PROFILER |
| struct ftrace_profile { |
| struct hlist_node node; |
| unsigned long ip; |
| unsigned long counter; |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| unsigned long long time; |
| unsigned long long time_squared; |
| #endif |
| }; |
| |
| struct ftrace_profile_page { |
| struct ftrace_profile_page *next; |
| unsigned long index; |
| struct ftrace_profile records[]; |
| }; |
| |
| struct ftrace_profile_stat { |
| atomic_t disabled; |
| struct hlist_head *hash; |
| struct ftrace_profile_page *pages; |
| struct ftrace_profile_page *start; |
| struct tracer_stat stat; |
| }; |
| |
| #define PROFILE_RECORDS_SIZE \ |
| (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) |
| |
| #define PROFILES_PER_PAGE \ |
| (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) |
| |
| static int ftrace_profile_enabled __read_mostly; |
| |
| /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ |
| static DEFINE_MUTEX(ftrace_profile_lock); |
| |
| static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
| |
| #define FTRACE_PROFILE_HASH_BITS 10 |
| #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) |
| |
| static void * |
| function_stat_next(void *v, int idx) |
| { |
| struct ftrace_profile *rec = v; |
| struct ftrace_profile_page *pg; |
| |
| pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
| |
| again: |
| if (idx != 0) |
| rec++; |
| |
| if ((void *)rec >= (void *)&pg->records[pg->index]) { |
| pg = pg->next; |
| if (!pg) |
| return NULL; |
| rec = &pg->records[0]; |
| if (!rec->counter) |
| goto again; |
| } |
| |
| return rec; |
| } |
| |
| static void *function_stat_start(struct tracer_stat *trace) |
| { |
| struct ftrace_profile_stat *stat = |
| container_of(trace, struct ftrace_profile_stat, stat); |
| |
| if (!stat || !stat->start) |
| return NULL; |
| |
| return function_stat_next(&stat->start->records[0], 0); |
| } |
| |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| /* function graph compares on total time */ |
| static int function_stat_cmp(void *p1, void *p2) |
| { |
| struct ftrace_profile *a = p1; |
| struct ftrace_profile *b = p2; |
| |
| if (a->time < b->time) |
| return -1; |
| if (a->time > b->time) |
| return 1; |
| else |
| return 0; |
| } |
| #else |
| /* not function graph compares against hits */ |
| static int function_stat_cmp(void *p1, void *p2) |
| { |
| struct ftrace_profile *a = p1; |
| struct ftrace_profile *b = p2; |
| |
| if (a->counter < b->counter) |
| return -1; |
| if (a->counter > b->counter) |
| return 1; |
| else |
| return 0; |
| } |
| #endif |
| |
| static int function_stat_headers(struct seq_file *m) |
| { |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| seq_puts(m, " Function " |
| "Hit Time Avg s^2\n" |
| " -------- " |
| "--- ---- --- ---\n"); |
| #else |
| seq_puts(m, " Function Hit\n" |
| " -------- ---\n"); |
| #endif |
| return 0; |
| } |
| |
| static int function_stat_show(struct seq_file *m, void *v) |
| { |
| struct ftrace_profile *rec = v; |
| char str[KSYM_SYMBOL_LEN]; |
| int ret = 0; |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| static struct trace_seq s; |
| unsigned long long avg; |
| unsigned long long stddev; |
| #endif |
| mutex_lock(&ftrace_profile_lock); |
| |
| /* we raced with function_profile_reset() */ |
| if (unlikely(rec->counter == 0)) { |
| ret = -EBUSY; |
| goto out; |
| } |
| |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| avg = rec->time; |
| do_div(avg, rec->counter); |
| if (tracing_thresh && (avg < tracing_thresh)) |
| goto out; |
| #endif |
| |
| kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
| seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
| |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| seq_puts(m, " "); |
| |
| /* Sample standard deviation (s^2) */ |
| if (rec->counter <= 1) |
| stddev = 0; |
| else { |
| /* |
| * Apply Welford's method: |
| * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) |
| */ |
| stddev = rec->counter * rec->time_squared - |
| rec->time * rec->time; |
| |
| /* |
| * Divide only 1000 for ns^2 -> us^2 conversion. |
| * trace_print_graph_duration will divide 1000 again. |
| */ |
| do_div(stddev, rec->counter * (rec->counter - 1) * 1000); |
| } |
| |
| trace_seq_init(&s); |
| trace_print_graph_duration(rec->time, &s); |
| trace_seq_puts(&s, " "); |
| trace_print_graph_duration(avg, &s); |
| trace_seq_puts(&s, " "); |
| trace_print_graph_duration(stddev, &s); |
| trace_print_seq(m, &s); |
| #endif |
| seq_putc(m, '\n'); |
| out: |
| mutex_unlock(&ftrace_profile_lock); |
| |
| return ret; |
| } |
| |
| static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
| { |
| struct ftrace_profile_page *pg; |
| |
| pg = stat->pages = stat->start; |
| |
| while (pg) { |
| memset(pg->records, 0, PROFILE_RECORDS_SIZE); |
| pg->index = 0; |
| pg = pg->next; |
| } |
| |
| memset(stat->hash, 0, |
| FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
| } |
| |
| int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
| { |
| struct ftrace_profile_page *pg; |
| int functions; |
| int pages; |
| int i; |
| |
| /* If we already allocated, do nothing */ |
| if (stat->pages) |
| return 0; |
| |
| stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
| if (!stat->pages) |
| return -ENOMEM; |
| |
| #ifdef CONFIG_DYNAMIC_FTRACE |
| functions = ftrace_update_tot_cnt; |
| #else |
| /* |
| * We do not know the number of functions that exist because |
| * dynamic tracing is what counts them. With past experience |
| * we have around 20K functions. That should be more than enough. |
| * It is highly unlikely we will execute every function in |
| * the kernel. |
| */ |
| functions = 20000; |
| #endif |
| |
| pg = stat->start = stat->pages; |
| |
| pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
| |
| for (i = 1; i < pages; i++) { |
| pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
| if (!pg->next) |
| goto out_free; |
| pg = pg->next; |
| } |
| |
| return 0; |
| |
| out_free: |
| pg = stat->start; |
| while (pg) { |
| unsigned long tmp = (unsigned long)pg; |
| |
| pg = pg->next; |
| free_page(tmp); |
| } |
| |
| stat->pages = NULL; |
| stat->start = NULL; |
| |
| return -ENOMEM; |
| } |
| |
| static int ftrace_profile_init_cpu(int cpu) |
| { |
| struct ftrace_profile_stat *stat; |
| int size; |
| |
| stat = &per_cpu(ftrace_profile_stats, cpu); |
| |
| if (stat->hash) { |
| /* If the profile is already created, simply reset it */ |
| ftrace_profile_reset(stat); |
| return 0; |
| } |
| |
| /* |
| * We are profiling all functions, but usually only a few thousand |
| * functions are hit. We'll make a hash of 1024 items. |
| */ |
| size = FTRACE_PROFILE_HASH_SIZE; |
| |
| stat->hash = kcalloc(size, sizeof(struct hlist_head), GFP_KERNEL); |
| |
| if (!stat->hash) |
| return -ENOMEM; |
| |
| /* Preallocate the function profiling pages */ |
| if (ftrace_profile_pages_init(stat) < 0) { |
| kfree(stat->hash); |
| stat->hash = NULL; |
| return -ENOMEM; |
| } |
| |
| return 0; |
| } |
| |
| static int ftrace_profile_init(void) |
| { |
| int cpu; |
| int ret = 0; |
| |
| for_each_possible_cpu(cpu) { |
| ret = ftrace_profile_init_cpu(cpu); |
| if (ret) |
| break; |
| } |
| |
| return ret; |
| } |
| |
| /* interrupts must be disabled */ |
| static struct ftrace_profile * |
| ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) |
| { |
| struct ftrace_profile *rec; |
| struct hlist_head *hhd; |
| unsigned long key; |
| |
| key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
| hhd = &stat->hash[key]; |
| |
| if (hlist_empty(hhd)) |
| return NULL; |
| |
| hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
| if (rec->ip == ip) |
| return rec; |
| } |
| |
| return NULL; |
| } |
| |
| static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
| struct ftrace_profile *rec) |
| { |
| unsigned long key; |
| |
| key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
| hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
| } |
| |
| /* |
| * The memory is already allocated, this simply finds a new record to use. |
| */ |
| static struct ftrace_profile * |
| ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
| { |
| struct ftrace_profile *rec = NULL; |
| |
| /* prevent recursion (from NMIs) */ |
| if (atomic_inc_return(&stat->disabled) != 1) |
| goto out; |
| |
| /* |
| * Try to find the function again since an NMI |
| * could have added it |
| */ |
| rec = ftrace_find_profiled_func(stat, ip); |
| if (rec) |
| goto out; |
| |
| if (stat->pages->index == PROFILES_PER_PAGE) { |
| if (!stat->pages->next) |
| goto out; |
| stat->pages = stat->pages->next; |
| } |
| |
| rec = &stat->pages->records[stat->pages->index++]; |
| rec->ip = ip; |
| ftrace_add_profile(stat, rec); |
| |
| out: |
| atomic_dec(&stat->disabled); |
| |
| return rec; |
| } |
| |
| static void |
| function_profile_call(unsigned long ip, unsigned long parent_ip, |
| struct ftrace_ops *ops, struct pt_regs *regs) |
| { |
| struct ftrace_profile_stat *stat; |
| struct ftrace_profile *rec; |
| unsigned long flags; |
| |
| if (!ftrace_profile_enabled) |
| return; |
| |
| local_irq_save(flags); |
| |
| stat = this_cpu_ptr(&ftrace_profile_stats); |
| if (!stat->hash || !ftrace_profile_enabled) |
| goto out; |
| |
| rec = ftrace_find_profiled_func(stat, ip); |
| if (!rec) { |
| rec = ftrace_profile_alloc(stat, ip); |
| if (!rec) |
| goto out; |
| } |
| |
| rec->counter++; |
| out: |
| local_irq_restore(flags); |
| } |
| |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| static bool fgraph_graph_time = true; |
| |
| void ftrace_graph_graph_time_control(bool enable) |
| { |
| fgraph_graph_time = enable; |
| } |
| |
| static int profile_graph_entry(struct ftrace_graph_ent *trace) |
| { |
| struct ftrace_ret_stack *ret_stack; |
| |
| function_profile_call(trace->func, 0, NULL, NULL); |
| |
| /* If function graph is shutting down, ret_stack can be NULL */ |
| if (!current->ret_stack) |
| return 0; |
| |
| ret_stack = ftrace_graph_get_ret_stack(current, 0); |
| if (ret_stack) |
| ret_stack->subtime = 0; |
| |
| return 1; |
| } |
| |
| static void profile_graph_return(struct ftrace_graph_ret *trace) |
| { |
| struct ftrace_ret_stack *ret_stack; |
| struct ftrace_profile_stat *stat; |
| unsigned long long calltime; |
| struct ftrace_profile *rec; |
| unsigned long flags; |
| |
| local_irq_save(flags); |
| stat = this_cpu_ptr(&ftrace_profile_stats); |
| if (!stat->hash || !ftrace_profile_enabled) |
| goto out; |
| |
| /* If the calltime was zero'd ignore it */ |
| if (!trace->calltime) |
| goto out; |
| |
| calltime = trace->rettime - trace->calltime; |
| |
| if (!fgraph_graph_time) { |
| |
| /* Append this call time to the parent time to subtract */ |
| ret_stack = ftrace_graph_get_ret_stack(current, 1); |
| if (ret_stack) |
| ret_stack->subtime += calltime; |
| |
| ret_stack = ftrace_graph_get_ret_stack(current, 0); |
| if (ret_stack && ret_stack->subtime < calltime) |
| calltime -= ret_stack->subtime; |
| else |
| calltime = 0; |
| } |
| |
| rec = ftrace_find_profiled_func(stat, trace->func); |
| if (rec) { |
| rec->time += calltime; |
| rec->time_squared += calltime * calltime; |
| } |
| |
| out: |
| local_irq_restore(flags); |
| } |
| |
| static struct fgraph_ops fprofiler_ops = { |
| .entryfunc = &profile_graph_entry, |
| .retfunc = &profile_graph_return, |
| }; |
| |
| static int register_ftrace_profiler(void) |
| { |
| return register_ftrace_graph(&fprofiler_ops); |
| } |
| |
| static void unregister_ftrace_profiler(void) |
| { |
| unregister_ftrace_graph(&fprofiler_ops); |
| } |
| #else |
| static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
| .func = function_profile_call, |
| .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
| INIT_OPS_HASH(ftrace_profile_ops) |
| }; |
| |
| static int register_ftrace_profiler(void) |
| { |
| return register_ftrace_function(&ftrace_profile_ops); |
| } |
| |
| static void unregister_ftrace_profiler(void) |
| { |
| unregister_ftrace_function(&ftrace_profile_ops); |
| } |
| #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
| |
| static ssize_t |
| ftrace_profile_write(struct file *filp, const char __user *ubuf, |
| size_t cnt, loff_t *ppos) |
| { |
| unsigned long val; |
| int ret; |
| |
| ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
| if (ret) |
| return ret; |
| |
| val = !!val; |
| |
| mutex_lock(&ftrace_profile_lock); |
| if (ftrace_profile_enabled ^ val) { |
| if (val) { |
| ret = ftrace_profile_init(); |
| if (ret < 0) { |
| cnt = ret; |
| goto out; |
| } |
| |
| ret = register_ftrace_profiler(); |
| if (ret < 0) { |
| cnt = ret; |
| goto out; |
| } |
| ftrace_profile_enabled = 1; |
| } else { |
| ftrace_profile_enabled = 0; |
| /* |
| * unregister_ftrace_profiler calls stop_machine |
| * so this acts like an synchronize_rcu. |
| */ |
| unregister_ftrace_profiler(); |
| } |
| } |
| out: |
| mutex_unlock(&ftrace_profile_lock); |
| |
| *ppos += cnt; |
| |
| return cnt; |
| } |
| |
| static ssize_t |
| ftrace_profile_read(struct file *filp, char __user *ubuf, |
| size_t cnt, loff_t *ppos) |
| { |
| char buf[64]; /* big enough to hold a number */ |
| int r; |
| |
| r = sprintf(buf, "%u\n", ftrace_profile_enabled); |
| return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
| } |
| |
| static const struct file_operations ftrace_profile_fops = { |
| .open = tracing_open_generic, |
| .read = ftrace_profile_read, |
| .write = ftrace_profile_write, |
| .llseek = default_llseek, |
| }; |
| |
| /* used to initialize the real stat files */ |
| static struct tracer_stat function_stats __initdata = { |
| .name = "functions", |
| .stat_start = function_stat_start, |
| .stat_next = function_stat_next, |
| .stat_cmp = function_stat_cmp, |
| .stat_headers = function_stat_headers, |
| .stat_show = function_stat_show |
| }; |
| |
| static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
| { |
| struct ftrace_profile_stat *stat; |
| struct dentry *entry; |
| char *name; |
| int ret; |
| int cpu; |
| |
| for_each_possible_cpu(cpu) { |
| stat = &per_cpu(ftrace_profile_stats, cpu); |
| |
| name = kasprintf(GFP_KERNEL, "function%d", cpu); |
| if (!name) { |
| /* |
| * The files created are permanent, if something happens |
| * we still do not free memory. |
| */ |
| WARN(1, |
| "Could not allocate stat file for cpu %d\n", |
| cpu); |
| return; |
| } |
| stat->stat = function_stats; |
| stat->stat.name = name; |
| ret = register_stat_tracer(&stat->stat); |
| if (ret) { |
| WARN(1, |
| "Could not register function stat for cpu %d\n", |
| cpu); |
| kfree(name); |
| return; |
| } |
| } |
| |
| entry = tracefs_create_file("function_profile_enabled", 0644, |
| d_tracer, NULL, &ftrace_profile_fops); |
| if (!entry) |
| pr_warn("Could not create tracefs 'function_profile_enabled' entry\n"); |
| } |
| |
| #else /* CONFIG_FUNCTION_PROFILER */ |
| static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
| { |
| } |
| #endif /* CONFIG_FUNCTION_PROFILER */ |
| |
| #ifdef CONFIG_DYNAMIC_FTRACE |
| |
| static struct ftrace_ops *removed_ops; |
| |
| /* |
| * Set when doing a global update, like enabling all recs or disabling them. |
| * It is not set when just updating a single ftrace_ops. |
| */ |
| static bool update_all_ops; |
| |
| #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
| # error Dynamic ftrace depends on MCOUNT_RECORD |
| #endif |
| |
| struct ftrace_func_entry { |
| struct hlist_node hlist; |
| unsigned long ip; |
| }; |
| |
| struct ftrace_func_probe { |
| struct ftrace_probe_ops *probe_ops; |
| struct ftrace_ops ops; |
| struct trace_array *tr; |
| struct list_head list; |
| void *data; |
| int ref; |
| }; |
| |
| /* |
| * We make these constant because no one should touch them, |
| * but they are used as the default "empty hash", to avoid allocating |
| * it all the time. These are in a read only section such that if |
| * anyone does try to modify it, it will cause an exception. |
| */ |
| static const struct hlist_head empty_buckets[1]; |
| static const struct ftrace_hash empty_hash = { |
| .buckets = (struct hlist_head *)empty_buckets, |
| }; |
| #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
| |
| struct ftrace_ops global_ops = { |
| .func = ftrace_stub, |
| .local_hash.notrace_hash = EMPTY_HASH, |
| .local_hash.filter_hash = EMPTY_HASH, |
| INIT_OPS_HASH(global_ops) |
| .flags = FTRACE_OPS_FL_RECURSION_SAFE | |
| FTRACE_OPS_FL_INITIALIZED | |
| FTRACE_OPS_FL_PID, |
| }; |
| |
| /* |
| * Used by the stack undwinder to know about dynamic ftrace trampolines. |
| */ |
| struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr) |
| { |
| struct ftrace_ops *op = NULL; |
| |
| /* |
| * Some of the ops may be dynamically allocated, |
| * they are freed after a synchronize_rcu(). |
| */ |
| preempt_disable_notrace(); |
| |
| do_for_each_ftrace_op(op, ftrace_ops_list) { |
| /* |
| * This is to check for dynamically allocated trampolines. |
| * Trampolines that are in kernel text will have |
| * core_kernel_text() return true. |
| */ |
| if (op->trampoline && op->trampoline_size) |
| if (addr >= op->trampoline && |
| addr < op->trampoline + op->trampoline_size) { |
| preempt_enable_notrace(); |
| return op; |
| } |
| } while_for_each_ftrace_op(op); |
| preempt_enable_notrace(); |
| |
| return NULL; |
| } |
| |
| /* |
| * This is used by __kernel_text_address() to return true if the |
| * address is on a dynamically allocated trampoline that would |
| * not return true for either core_kernel_text() or |
| * is_module_text_address(). |
| */ |
| bool is_ftrace_trampoline(unsigned long addr) |
| { |
| return ftrace_ops_trampoline(addr) != NULL; |
| } |
| |
| struct ftrace_page { |
| struct ftrace_page *next; |
| struct dyn_ftrace *records; |
| int index; |
| int size; |
| }; |
| |
| #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
| #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) |
| |
| /* estimate from running different kernels */ |
| #define NR_TO_INIT 10000 |
| |
| static struct ftrace_page *ftrace_pages_start; |
| static struct ftrace_page *ftrace_pages; |
| |
| static __always_inline unsigned long |
| ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip) |
| { |
| if (hash->size_bits > 0) |
| return hash_long(ip, hash->size_bits); |
| |
| return 0; |
| } |
| |
| /* Only use this function if ftrace_hash_empty() has already been tested */ |
| static __always_inline struct ftrace_func_entry * |
| __ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) |
| { |
| unsigned long key; |
| struct ftrace_func_entry *entry; |
| struct hlist_head *hhd; |
| |
| key = ftrace_hash_key(hash, ip); |
| hhd = &hash->buckets[key]; |
| |
| hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
| if (entry->ip == ip) |
| return entry; |
| } |
| return NULL; |
| } |
| |
| /** |
| * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash |
| * @hash: The hash to look at |
| * @ip: The instruction pointer to test |
| * |
| * Search a given @hash to see if a given instruction pointer (@ip) |
| * exists in it. |
| * |
| * Returns the entry that holds the @ip if found. NULL otherwise. |
| */ |
| struct ftrace_func_entry * |
| ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) |
| { |
| if (ftrace_hash_empty(hash)) |
| return NULL; |
| |
| return __ftrace_lookup_ip(hash, ip); |
| } |
| |
| static void __add_hash_entry(struct ftrace_hash *hash, |
| struct ftrace_func_entry *entry) |
| { |
| struct hlist_head *hhd; |
| unsigned long key; |
| |
| key = ftrace_hash_key(hash, entry->ip); |
| hhd = &hash->buckets[key]; |
| hlist_add_head(&entry->hlist, hhd); |
| hash->count++; |
| } |
| |
| static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) |
| { |
| struct ftrace_func_entry *entry; |
| |
| entry = kmalloc(sizeof(*entry), GFP_KERNEL); |
| if (!entry) |
| return -ENOMEM; |
| |
| entry->ip = ip; |
| __add_hash_entry(hash, entry); |
| |
| return 0; |
| } |
| |
| static void |
| free_hash_entry(struct ftrace_hash *hash, |
| struct ftrace_func_entry *entry) |
| { |
| hlist_del(&entry->hlist); |
| kfree(entry); |
| hash->count--; |
| } |
| |
| static void |
| remove_hash_entry(struct ftrace_hash *hash, |
| struct ftrace_func_entry *entry) |
| { |
| hlist_del_rcu(&entry->hlist); |
| hash->count--; |
| } |
| |
| static void ftrace_hash_clear(struct ftrace_hash *hash) |
| { |
| struct hlist_head *hhd; |
| struct hlist_node *tn; |
| struct ftrace_func_entry *entry; |
| int size = 1 << hash->size_bits; |
| int i; |
| |
| if (!hash->count) |
| return; |
| |
| for (i = 0; i < size; i++) { |
| hhd = &hash->buckets[i]; |
| hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
| free_hash_entry(hash, entry); |
| } |
| FTRACE_WARN_ON(hash->count); |
| } |
| |
| static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod) |
| { |
| list_del(&ftrace_mod->list); |
| kfree(ftrace_mod->module); |
| kfree(ftrace_mod->func); |
| kfree(ftrace_mod); |
| } |
| |
| static void clear_ftrace_mod_list(struct list_head *head) |
| { |
| struct ftrace_mod_load *p, *n; |
| |
| /* stack tracer isn't supported yet */ |
| if (!head) |
| return; |
| |
| mutex_lock(&ftrace_lock); |
| list_for_each_entry_safe(p, n, head, list) |
| free_ftrace_mod(p); |
| mutex_unlock(&ftrace_lock); |
| } |
| |
| static void free_ftrace_hash(struct ftrace_hash *hash) |
| { |
| if (!hash || hash == EMPTY_HASH) |
| return; |
| ftrace_hash_clear(hash); |
| kfree(hash->buckets); |
| kfree(hash); |
| } |
| |
| static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
| { |
| struct ftrace_hash *hash; |
| |
| hash = container_of(rcu, struct ftrace_hash, rcu); |
| free_ftrace_hash(hash); |
| } |
| |
| static void free_ftrace_hash_rcu(struct ftrace_hash *hash) |
| { |
| if (!hash || hash == EMPTY_HASH) |
| return; |
| call_rcu(&hash->rcu, __free_ftrace_hash_rcu); |
| } |
| |
| void ftrace_free_filter(struct ftrace_ops *ops) |
| { |
| ftrace_ops_init(ops); |
| free_ftrace_hash(ops->func_hash->filter_hash); |
| free_ftrace_hash(ops->func_hash->notrace_hash); |
| } |
| |
| static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
| { |
| struct ftrace_hash *hash; |
| int size; |
| |
| hash = kzalloc(sizeof(*hash), GFP_KERNEL); |
| if (!hash) |
| return NULL; |
| |
| size = 1 << size_bits; |
| hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
| |
| if (!hash->buckets) { |
| kfree(hash); |
| return NULL; |
| } |
| |
| hash->size_bits = size_bits; |
| |
| return hash; |
| } |
| |
| |
| static int ftrace_add_mod(struct trace_array *tr, |
| const char *func, const char *module, |
| int enable) |
| { |
| struct ftrace_mod_load *ftrace_mod; |
| struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace; |
| |
| ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL); |
| if (!ftrace_mod) |
| return -ENOMEM; |
| |
| ftrace_mod->func = kstrdup(func, GFP_KERNEL); |
| ftrace_mod->module = kstrdup(module, GFP_KERNEL); |
| ftrace_mod->enable = enable; |
| |
| if (!ftrace_mod->func || !ftrace_mod->module) |
| goto out_free; |
| |
| list_add(&ftrace_mod->list, mod_head); |
| |
| return 0; |
| |
| out_free: |
| free_ftrace_mod(ftrace_mod); |
| |
| return -ENOMEM; |
| } |
| |
| static struct ftrace_hash * |
| alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) |
| { |
| struct ftrace_func_entry *entry; |
| struct ftrace_hash *new_hash; |
| int size; |
| int ret; |
| int i; |
| |
| new_hash = alloc_ftrace_hash(size_bits); |
| if (!new_hash) |
| return NULL; |
| |
| if (hash) |
| new_hash->flags = hash->flags; |
| |
| /* Empty hash? */ |
| if (ftrace_hash_empty(hash)) |
| return new_hash; |
| |
| size = 1 << hash->size_bits; |
| for (i = 0; i < size; i++) { |
| hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
| ret = add_hash_entry(new_hash, entry->ip); |
| if (ret < 0) |
| goto free_hash; |
| } |
| } |
| |
| FTRACE_WARN_ON(new_hash->count != hash->count); |
| |
| return new_hash; |
| |
| free_hash: |
| free_ftrace_hash(new_hash); |
| return NULL; |
| } |
| |
| static void |
| ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash); |
| static void |
| ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash); |
| |
| static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, |
| struct ftrace_hash *new_hash); |
| |
| static struct ftrace_hash * |
| __ftrace_hash_move(struct ftrace_hash *src) |
| { |
| struct ftrace_func_entry *entry; |
| struct hlist_node *tn; |
| struct hlist_head *hhd; |
| struct ftrace_hash *new_hash; |
| int size = src->count; |
| int bits = 0; |
| int i; |
| |
| /* |
| * If the new source is empty, just return the empty_hash. |
| */ |
| if (ftrace_hash_empty(src)) |
| return EMPTY_HASH; |
| |
| /* |
| * Make the hash size about 1/2 the # found |
| */ |
| for (size /= 2; size; size >>= 1) |
| bits++; |
| |
| /* Don't allocate too much */ |
| if (bits > FTRACE_HASH_MAX_BITS) |
| bits = FTRACE_HASH_MAX_BITS; |
| |
| new_hash = alloc_ftrace_hash(bits); |
| if (!new_hash) |
| return NULL; |
| |
| new_hash->flags = src->flags; |
| |
| size = 1 << src->size_bits; |
| for (i = 0; i < size; i++) { |
| hhd = &src->buckets[i]; |
| hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
| remove_hash_entry(src, entry); |
| __add_hash_entry(new_hash, entry); |
| } |
| } |
| |
| return new_hash; |
| } |
| |
| static int |
| ftrace_hash_move(struct ftrace_ops *ops, int enable, |
| struct ftrace_hash **dst, struct ftrace_hash *src) |
| { |
| struct ftrace_hash *new_hash; |
| int ret; |
| |
| /* Reject setting notrace hash on IPMODIFY ftrace_ops */ |
| if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable) |
| return -EINVAL; |
| |
| new_hash = __ftrace_hash_move(src); |
| if (!new_hash) |
| return -ENOMEM; |
| |
| /* Make sure this can be applied if it is IPMODIFY ftrace_ops */ |
| if (enable) { |
| /* IPMODIFY should be updated only when filter_hash updating */ |
| ret = ftrace_hash_ipmodify_update(ops, new_hash); |
| if (ret < 0) { |
| free_ftrace_hash(new_hash); |
| return ret; |
| } |
| } |
| |
| /* |
| * Remove the current set, update the hash and add |
| * them back. |
| */ |
| ftrace_hash_rec_disable_modify(ops, enable); |
| |
| rcu_assign_pointer(*dst, new_hash); |
| |
| ftrace_hash_rec_enable_modify(ops, enable); |
| |
| return 0; |
| } |
| |
| static bool hash_contains_ip(unsigned long ip, |
| struct ftrace_ops_hash *hash) |
| { |
| /* |
| * The function record is a match if it exists in the filter |
| * hash and not in the notrace hash. Note, an emty hash is |
| * considered a match for the filter hash, but an empty |
| * notrace hash is considered not in the notrace hash. |
| */ |
| return (ftrace_hash_empty(hash->filter_hash) || |
| __ftrace_lookup_ip(hash->filter_hash, ip)) && |
| (ftrace_hash_empty(hash->notrace_hash) || |
| !__ftrace_lookup_ip(hash->notrace_hash, ip)); |
| } |
| |
| /* |
| * Test the hashes for this ops to see if we want to call |
| * the ops->func or not. |
| * |
| * It's a match if the ip is in the ops->filter_hash or |
| * the filter_hash does not exist or is empty, |
| * AND |
| * the ip is not in the ops->notrace_hash. |
| * |
| * This needs to be called with preemption disabled as |
| * the hashes are freed with call_rcu(). |
| */ |
| int |
| ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
| { |
| struct ftrace_ops_hash hash; |
| int ret; |
| |
| #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
| /* |
| * There's a small race when adding ops that the ftrace handler |
| * that wants regs, may be called without them. We can not |
| * allow that handler to be called if regs is NULL. |
| */ |
| if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) |
| return 0; |
| #endif |
| |
| rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash); |
| rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash); |
| |
| if (hash_contains_ip(ip, &hash)) |
| ret = 1; |
| else |
| ret = 0; |
| |
| return ret; |
| } |
| |
| /* |
| * This is a double for. Do not use 'break' to break out of the loop, |
| * you must use a goto. |
| */ |
| #define do_for_each_ftrace_rec(pg, rec) \ |
| for (pg = ftrace_pages_start; pg; pg = pg->next) { \ |
| int _____i; \ |
| for (_____i = 0; _____i < pg->index; _____i++) { \ |
| rec = &pg->records[_____i]; |
| |
| #define while_for_each_ftrace_rec() \ |
| } \ |
| } |
| |
| |
| static int ftrace_cmp_recs(const void *a, const void *b) |
| { |
| const struct dyn_ftrace *key = a; |
| const struct dyn_ftrace *rec = b; |
| |
| if (key->flags < rec->ip) |
| return -1; |
| if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
| return 1; |
| return 0; |
| } |
| |
| /** |
| * ftrace_location_range - return the first address of a traced location |
| * if it touches the given ip range |
| * @start: start of range to search. |
| * @end: end of range to search (inclusive). @end points to the last byte |
| * to check. |
| * |
| * Returns rec->ip if the related ftrace location is a least partly within |
| * the given address range. That is, the first address of the instruction |
| * that is either a NOP or call to the function tracer. It checks the ftrace |
| * internal tables to determine if the address belongs or not. |
| */ |
| unsigned long ftrace_location_range(unsigned long start, unsigned long end) |
| { |
| struct ftrace_page *pg; |
| struct dyn_ftrace *rec; |
| struct dyn_ftrace key; |
| |
| key.ip = start; |
| key.flags = end; /* overload flags, as it is unsigned long */ |
| |
| for (pg = ftrace_pages_start; pg; pg = pg->next) { |
| if (end < pg->records[0].ip || |
| start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) |
| continue; |
| rec = bsearch(&key, pg->records, pg->index, |
| sizeof(struct dyn_ftrace), |
| ftrace_cmp_recs); |
| if (rec) |
| return rec->ip; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * ftrace_location - return true if the ip giving is a traced location |
| * @ip: the instruction pointer to check |
| * |
| * Returns rec->ip if @ip given is a pointer to a ftrace location. |
| * That is, the instruction that is either a NOP or call to |
| * the function tracer. It checks the ftrace internal tables to |
| * determine if the address belongs or not. |
| */ |
| unsigned long ftrace_location(unsigned long ip) |
| { |
| return ftrace_location_range(ip, ip); |
| } |
| |
| /** |
| * ftrace_text_reserved - return true if range contains an ftrace location |
| * @start: start of range to search |
| * @end: end of range to search (inclusive). @end points to the last byte to check. |
| * |
| * Returns 1 if @start and @end contains a ftrace location. |
| * That is, the instruction that is either a NOP or call to |
| * the function tracer. It checks the ftrace internal tables to |
| * determine if the address belongs or not. |
| */ |
| int ftrace_text_reserved(const void *start, const void *end) |
| { |
| unsigned long ret; |
| |
| ret = ftrace_location_range((unsigned long)start, |
| (unsigned long)end); |
| |
| return (int)!!ret; |
| } |
| |
| /* Test if ops registered to this rec needs regs */ |
| static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec) |
| { |
| struct ftrace_ops *ops; |
| bool keep_regs = false; |
| |
| for (ops = ftrace_ops_list; |
| ops != &ftrace_list_end; ops = ops->next) { |
| /* pass rec in as regs to have non-NULL val */ |
| if (ftrace_ops_test(ops, rec->ip, rec)) { |
| if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { |
| keep_regs = true; |
| break; |
| } |
| } |
| } |
| |
| return keep_regs; |
| } |
| |
| static bool __ftrace_hash_rec_update(struct ftrace_ops *ops, |
| int filter_hash, |
| bool inc) |
| { |
| struct ftrace_hash *hash; |
| struct ftrace_hash *other_hash; |
| struct ftrace_page *pg; |
| struct dyn_ftrace *rec; |
| bool update = false; |
| int count = 0; |
| int all = false; |
| |
| /* Only update if the ops has been registered */ |
| if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) |
| return false; |
| |
| /* |
| * In the filter_hash case: |
| * If the count is zero, we update all records. |
| * Otherwise we just update the items in the hash. |
| * |
| * In the notrace_hash case: |
| * We enable the update in the hash. |
| * As disabling notrace means enabling the tracing, |
| * and enabling notrace means disabling, the inc variable |
| * gets inversed. |
| */ |
| if (filter_hash) { |
| hash = ops->func_hash->filter_hash; |
| other_hash = ops->func_hash->notrace_hash; |
| if (ftrace_hash_empty(hash)) |
| all = true; |
| } else { |
| inc = !inc; |
| hash = ops->func_hash->notrace_hash; |
| other_hash = ops->func_hash->filter_hash; |
| /* |
| * If the notrace hash has no items, |
| * then there's nothing to do. |
| */ |
| if (ftrace_hash_empty(hash)) |
| return false; |
| } |
| |
| do_for_each_ftrace_rec(pg, rec) { |
| int in_other_hash = 0; |
| int in_hash = 0; |
| int match = 0; |
| |
| if (rec->flags & FTRACE_FL_DISABLED) |
| continue; |
| |
| if (all) { |
| /* |
| * Only the filter_hash affects all records. |
| * Update if the record is not in the notrace hash. |
| */ |
| if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
| match = 1; |
| } else { |
| in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
| in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); |
| |
| /* |
| * If filter_hash is set, we want to match all functions |
| * that are in the hash but not in the other hash. |
| * |
| * If filter_hash is not set, then we are decrementing. |
| * That means we match anything that is in the hash |
| * and also in the other_hash. That is, we need to turn |
| * off functions in the other hash because they are disabled |
| * by this hash. |
| */ |
| if (filter_hash && in_hash && !in_other_hash) |
| match = 1; |
| else if (!filter_hash && in_hash && |
| (in_other_hash || ftrace_hash_empty(other_hash))) |
| match = 1; |
| } |
| if (!match) |
| continue; |
| |
| if (inc) { |
| rec->flags++; |
| if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX)) |
| return false; |
| |
| /* |
| * If there's only a single callback registered to a |
| * function, and the ops has a trampoline registered |
| * for it, then we can call it directly. |
| */ |
| if (ftrace_rec_count(rec) == 1 && ops->trampoline) |
| rec->flags |= FTRACE_FL_TRAMP; |
| else |
| /* |
| * If we are adding another function callback |
| * to this function, and the previous had a |
| * custom trampoline in use, then we need to go |
| * back to the default trampoline. |
| */ |
| rec->flags &= ~FTRACE_FL_TRAMP; |
| |
| /* |
| * If any ops wants regs saved for this function |
| * then all ops will get saved regs. |
| */ |
| if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) |
| rec->flags |= FTRACE_FL_REGS; |
| } else { |
| if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0)) |
| return false; |
| rec->flags--; |
| |
| /* |
| * If the rec had REGS enabled and the ops that is |
| * being removed had REGS set, then see if there is |
| * still any ops for this record that wants regs. |
| * If not, we can stop recording them. |
| */ |
| if (ftrace_rec_count(rec) > 0 && |
| rec->flags & FTRACE_FL_REGS && |
| ops->flags & FTRACE_OPS_FL_SAVE_REGS) { |
| if (!test_rec_ops_needs_regs(rec)) |
| rec->flags &= ~FTRACE_FL_REGS; |
| } |
| |
| /* |
| * If the rec had TRAMP enabled, then it needs to |
| * be cleared. As TRAMP can only be enabled iff |
| * there is only a single ops attached to it. |
| * In otherwords, always disable it on decrementing. |
| * In the future, we may set it if rec count is |
| * decremented to one, and the ops that is left |
| * has a trampoline. |
| */ |
| rec->flags &= ~FTRACE_FL_TRAMP; |
| |
| /* |
| * flags will be cleared in ftrace_check_record() |
| * if rec count is zero. |
| */ |
| } |
| count++; |
| |
| /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */ |
| update |= ftrace_test_record(rec, 1) != FTRACE_UPDATE_IGNORE; |
| |
| /* Shortcut, if we handled all records, we are done. */ |
| if (!all && count == hash->count) |
| return update; |
| } while_for_each_ftrace_rec(); |
| |
| return update; |
| } |
| |
| static bool ftrace_hash_rec_disable(struct ftrace_ops *ops, |
| int filter_hash) |
| { |
| return __ftrace_hash_rec_update(ops, filter_hash, 0); |
| } |
| |
| static bool ftrace_hash_rec_enable(struct ftrace_ops *ops, |
| int filter_hash) |
| { |
| return __ftrace_hash_rec_update(ops, filter_hash, 1); |
| } |
| |
| static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, |
| int filter_hash, int inc) |
| { |
| struct ftrace_ops *op; |
| |
| __ftrace_hash_rec_update(ops, filter_hash, inc); |
| |
| if (ops->func_hash != &global_ops.local_hash) |
| return; |
| |
| /* |
| * If the ops shares the global_ops hash, then we need to update |
| * all ops that are enabled and use this hash. |
| */ |
| do_for_each_ftrace_op(op, ftrace_ops_list) { |
| /* Already done */ |
| if (op == ops) |
| continue; |
| if (op->func_hash == &global_ops.local_hash) |
| __ftrace_hash_rec_update(op, filter_hash, inc); |
| } while_for_each_ftrace_op(op); |
| } |
| |
| static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, |
| int filter_hash) |
| { |
| ftrace_hash_rec_update_modify(ops, filter_hash, 0); |
| } |
| |
| static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, |
| int filter_hash) |
| { |
| ftrace_hash_rec_update_modify(ops, filter_hash, 1); |
| } |
| |
| /* |
| * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK |
| * or no-needed to update, -EBUSY if it detects a conflict of the flag |
| * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs. |
| * Note that old_hash and new_hash has below meanings |
| * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected) |
| * - If the hash is EMPTY_HASH, it hits nothing |
| * - Anything else hits the recs which match the hash entries. |
| */ |
| static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops, |
| struct ftrace_hash *old_hash, |
| struct ftrace_hash *new_hash) |
| { |
| struct ftrace_page *pg; |
| struct dyn_ftrace *rec, *end = NULL; |
| int in_old, in_new; |
| |
| /* Only update if the ops has been registered */ |
| if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) |
| return 0; |
| |
| if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) |
| return 0; |
| |
| /* |
| * Since the IPMODIFY is a very address sensitive action, we do not |
| * allow ftrace_ops to set all functions to new hash. |
| */ |
| if (!new_hash || !old_hash) |
| return -EINVAL; |
| |
| /* Update rec->flags */ |
| do_for_each_ftrace_rec(pg, rec) { |
| |
| if (rec->flags & FTRACE_FL_DISABLED) |
| continue; |
| |
| /* We need to update only differences of filter_hash */ |
| in_old = !!ftrace_lookup_ip(old_hash, rec->ip); |
| in_new = !!ftrace_lookup_ip(new_hash, rec->ip); |
| if (in_old == in_new) |
| continue; |
| |
| if (in_new) { |
| /* New entries must ensure no others are using it */ |
| if (rec->flags & FTRACE_FL_IPMODIFY) |
| goto rollback; |
| rec->flags |= FTRACE_FL_IPMODIFY; |
| } else /* Removed entry */ |
| rec->flags &= ~FTRACE_FL_IPMODIFY; |
| } while_for_each_ftrace_rec(); |
| |
| return 0; |
| |
| rollback: |
| end = rec; |
| |
| /* Roll back what we did above */ |
| do_for_each_ftrace_rec(pg, rec) { |
| |
| if (rec->flags & FTRACE_FL_DISABLED) |
| continue; |
| |
| if (rec == end) |
| goto err_out; |
| |
| in_old = !!ftrace_lookup_ip(old_hash, rec->ip); |
| in_new = !!ftrace_lookup_ip(new_hash, rec->ip); |
| if (in_old == in_new) |
| continue; |
| |
| if (in_new) |
| rec->flags &= ~FTRACE_FL_IPMODIFY; |
| else |
| rec->flags |= FTRACE_FL_IPMODIFY; |
| } while_for_each_ftrace_rec(); |
| |
| err_out: |
| return -EBUSY; |
| } |
| |
| static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops) |
| { |
| struct ftrace_hash *hash = ops->func_hash->filter_hash; |
| |
| if (ftrace_hash_empty(hash)) |
| hash = NULL; |
| |
| return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash); |
| } |
| |
| /* Disabling always succeeds */ |
| static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops) |
| { |
| struct ftrace_hash *hash = ops->func_hash->filter_hash; |
| |
| if (ftrace_hash_empty(hash)) |
| hash = NULL; |
| |
| __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH); |
| } |
| |
| static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, |
| struct ftrace_hash *new_hash) |
| { |
| struct ftrace_hash *old_hash = ops->func_hash->filter_hash; |
| |
| if (ftrace_hash_empty(old_hash)) |
| old_hash = NULL; |
| |
| if (ftrace_hash_empty(new_hash)) |
| new_hash = NULL; |
| |
| return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash); |
| } |
| |
| static void print_ip_ins(const char *fmt, const unsigned char *p) |
| { |
| int i; |
| |
| printk(KERN_CONT "%s", fmt); |
| |
| for (i = 0; i < MCOUNT_INSN_SIZE; i++) |
| printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); |
| } |
| |
| static struct ftrace_ops * |
| ftrace_find_tramp_ops_any(struct dyn_ftrace *rec); |
| static struct ftrace_ops * |
| ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops); |
| |
| enum ftrace_bug_type ftrace_bug_type; |
| const void *ftrace_expected; |
| |
| static void print_bug_type(void) |
| { |
| switch (ftrace_bug_type) { |
| case FTRACE_BUG_UNKNOWN: |
| break; |
| case FTRACE_BUG_INIT: |
| pr_info("Initializing ftrace call sites\n"); |
| break; |
| case FTRACE_BUG_NOP: |
| pr_info("Setting ftrace call site to NOP\n"); |
| break; |
| case FTRACE_BUG_CALL: |
| pr_info("Setting ftrace call site to call ftrace function\n"); |
| break; |
| case FTRACE_BUG_UPDATE: |
| pr_info("Updating ftrace call site to call a different ftrace function\n"); |
| break; |
| } |
| } |
| |
| /** |
| * ftrace_bug - report and shutdown function tracer |
| * @failed: The failed type (EFAULT, EINVAL, EPERM) |
| * @rec: The record that failed |
| * |
| * The arch code that enables or disables the function tracing |
| * can call ftrace_bug() when it has detected a problem in |
| * modifying the code. @failed should be one of either: |
| * EFAULT - if the problem happens on reading the @ip address |
| * EINVAL - if what is read at @ip is not what was expected |
| * EPERM - if the problem happens on writing to the @ip address |
| */ |
| void ftrace_bug(int failed, struct dyn_ftrace *rec) |
| { |
| unsigned long ip = rec ? rec->ip : 0; |
| |
| switch (failed) { |
| case -EFAULT: |
| FTRACE_WARN_ON_ONCE(1); |
| pr_info("ftrace faulted on modifying "); |
| print_ip_sym(ip); |
| break; |
| case -EINVAL: |
| FTRACE_WARN_ON_ONCE(1); |
| pr_info("ftrace failed to modify "); |
| print_ip_sym(ip); |
| print_ip_ins(" actual: ", (unsigned char *)ip); |
| pr_cont("\n"); |
| if (ftrace_expected) { |
| print_ip_ins(" expected: ", ftrace_expected); |
| pr_cont("\n"); |
| } |
| break; |
| case -EPERM: |
| FTRACE_WARN_ON_ONCE(1); |
| pr_info("ftrace faulted on writing "); |
| print_ip_sym(ip); |
| break; |
| default: |
| FTRACE_WARN_ON_ONCE(1); |
| pr_info("ftrace faulted on unknown error "); |
| print_ip_sym(ip); |
| } |
| print_bug_type(); |
| if (rec) { |
| struct ftrace_ops *ops = NULL; |
| |
| pr_info("ftrace record flags: %lx\n", rec->flags); |
| pr_cont(" (%ld)%s", ftrace_rec_count(rec), |
| rec->flags & FTRACE_FL_REGS ? " R" : " "); |
| if (rec->flags & FTRACE_FL_TRAMP_EN) { |
| ops = ftrace_find_tramp_ops_any(rec); |
| if (ops) { |
| do { |
| pr_cont("\ttramp: %pS (%pS)", |
| (void *)ops->trampoline, |
| (void *)ops->func); |
| ops = ftrace_find_tramp_ops_next(rec, ops); |
| } while (ops); |
| } else |
| pr_cont("\ttramp: ERROR!"); |
| |
| } |
| ip = ftrace_get_addr_curr(rec); |
| pr_cont("\n expected tramp: %lx\n", ip); |
| } |
| } |
| |
| static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) |
| { |
| unsigned long flag = 0UL; |
| |
| ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
| |
| if (rec->flags & FTRACE_FL_DISABLED) |
| return FTRACE_UPDATE_IGNORE; |
| |
| /* |
| * If we are updating calls: |
| * |
| * If the record has a ref count, then we need to enable it |
| * because someone is using it. |
| * |
| * Otherwise we make sure its disabled. |
| * |
| * If we are disabling calls, then disable all records that |
| * are enabled. |
| */ |
| if (enable && ftrace_rec_count(rec)) |
| flag = FTRACE_FL_ENABLED; |
| |
| /* |
| * If enabling and the REGS flag does not match the REGS_EN, or |
| * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore |
| * this record. Set flags to fail the compare against ENABLED. |
| */ |
| if (flag) { |
| if (!(rec->flags & FTRACE_FL_REGS) != |
| !(rec->flags & FTRACE_FL_REGS_EN)) |
| flag |= FTRACE_FL_REGS; |
| |
| if (!(rec->flags & FTRACE_FL_TRAMP) != |
| !(rec->flags & FTRACE_FL_TRAMP_EN)) |
| flag |= FTRACE_FL_TRAMP; |
| } |
| |
| /* If the state of this record hasn't changed, then do nothing */ |
| if ((rec->flags & FTRACE_FL_ENABLED) == flag) |
| return FTRACE_UPDATE_IGNORE; |
| |
| if (flag) { |
| /* Save off if rec is being enabled (for return value) */ |
| flag ^= rec->flags & FTRACE_FL_ENABLED; |
| |
| if (update) { |
| rec->flags |= FTRACE_FL_ENABLED; |
| if (flag & FTRACE_FL_REGS) { |
| if (rec->flags & FTRACE_FL_REGS) |
| rec->flags |= FTRACE_FL_REGS_EN; |
| else |
| rec->flags &= ~FTRACE_FL_REGS_EN; |
| } |
| if (flag & FTRACE_FL_TRAMP) { |
| if (rec->flags & FTRACE_FL_TRAMP) |
| rec->flags |= FTRACE_FL_TRAMP_EN; |
| else |
| rec->flags &= ~FTRACE_FL_TRAMP_EN; |
| } |
| } |
| |
| /* |
| * If this record is being updated from a nop, then |
| * return UPDATE_MAKE_CALL. |
| * Otherwise, |
| * return UPDATE_MODIFY_CALL to tell the caller to convert |
| * from the save regs, to a non-save regs function or |
| * vice versa, or from a trampoline call. |
| */ |
| if (flag & FTRACE_FL_ENABLED) { |
| ftrace_bug_type = FTRACE_BUG_CALL; |
| return FTRACE_UPDATE_MAKE_CALL; |
| } |
| |
| ftrace_bug_type = FTRACE_BUG_UPDATE; |
| return FTRACE_UPDATE_MODIFY_CALL; |
| } |
| |
| if (update) { |
| /* If there's no more users, clear all flags */ |
| if (!ftrace_rec_count(rec)) |
| rec->flags = 0; |
| else |
| /* |
| * Just disable the record, but keep the ops TRAMP |
| * and REGS states. The _EN flags must be disabled though. |
| */ |
| rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN | |
| FTRACE_FL_REGS_EN); |
| } |
| |
| ftrace_bug_type = FTRACE_BUG_NOP; |
| return FTRACE_UPDATE_MAKE_NOP; |
| } |
| |
| /** |
| * ftrace_update_record, set a record that now is tracing or not |
| * @rec: the record to update |
| * @enable: set to 1 if the record is tracing, zero to force disable |
| * |
| * The records that represent all functions that can be traced need |
| * to be updated when tracing has been enabled. |
| */ |
| int ftrace_update_record(struct dyn_ftrace *rec, int enable) |
| { |
| return ftrace_check_record(rec, enable, 1); |
| } |
| |
| /** |
| * ftrace_test_record, check if the record has been enabled or not |
| * @rec: the record to test |
| * @enable: set to 1 to check if enabled, 0 if it is disabled |
| * |
| * The arch code may need to test if a record is already set to |
| * tracing to determine how to modify the function code that it |
| * represents. |
| */ |
| int ftrace_test_record(struct dyn_ftrace *rec, int enable) |
| { |
| return ftrace_check_record(rec, enable, 0); |
| } |
| |
| static struct ftrace_ops * |
| ftrace_find_tramp_ops_any(struct dyn_ftrace *rec) |
| { |
| struct ftrace_ops *op; |
| unsigned long ip = rec->ip; |
| |
| do_for_each_ftrace_op(op, ftrace_ops_list) { |
| |
| if (!op->trampoline) |
| continue; |
| |
| if (hash_contains_ip(ip, op->func_hash)) |
| return op; |
| } while_for_each_ftrace_op(op); |
| |
| return NULL; |
| } |
| |
| static struct ftrace_ops * |
| ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, |
| struct ftrace_ops *op) |
| { |
| unsigned long ip = rec->ip; |
| |
| while_for_each_ftrace_op(op) { |
| |
| if (!op->trampoline) |
| continue; |
| |
| if (hash_contains_ip(ip, op->func_hash)) |
| return op; |
| } |
| |
| return NULL; |
| } |
| |
| static struct ftrace_ops * |
| ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) |
| { |
| struct ftrace_ops *op; |
| unsigned long ip = rec->ip; |
| |
| /* |
| * Need to check removed ops first. |
| * If they are being removed, and this rec has a tramp, |
| * and this rec is in the ops list, then it would be the |
| * one with the tramp. |
| */ |
| if (removed_ops) { |
| if (hash_contains_ip(ip, &removed_ops->old_hash)) |
| return removed_ops; |
| } |
| |
| /* |
| * Need to find the current trampoline for a rec. |
| * Now, a trampoline is only attached to a rec if there |
| * was a single 'ops' attached to it. But this can be called |
| * when we are adding another op to the rec or removing the |
| * current one. Thus, if the op is being added, we can |
| * ignore it because it hasn't attached itself to the rec |
| * yet. |
| * |
| * If an ops is being modified (hooking to different functions) |
| * then we don't care about the new functions that are being |
| * added, just the old ones (that are probably being removed). |
| * |
| * If we are adding an ops to a function that already is using |
| * a trampoline, it needs to be removed (trampolines are only |
| * for single ops connected), then an ops that is not being |
| * modified also needs to be checked. |
| */ |
| do_for_each_ftrace_op(op, ftrace_ops_list) { |
| |
| if (!op->trampoline) |
| continue; |
| |
| /* |
| * If the ops is being added, it hasn't gotten to |
| * the point to be removed from this tree yet. |
| */ |
| if (op->flags & FTRACE_OPS_FL_ADDING) |
| continue; |
| |
| |
| /* |
| * If the ops is being modified and is in the old |
| * hash, then it is probably being removed from this |
| * function. |
| */ |
| if ((op->flags & FTRACE_OPS_FL_MODIFYING) && |
| hash_contains_ip(ip, &op->old_hash)) |
| return op; |
| /* |
| * If the ops is not being added or modified, and it's |
| * in its normal filter hash, then this must be the one |
| * we want! |
| */ |
| if (!(op->flags & FTRACE_OPS_FL_MODIFYING) && |
| hash_contains_ip(ip, op->func_hash)) |
| return op; |
| |
| } while_for_each_ftrace_op(op); |
| |
| return NULL; |
| } |
| |
| static struct ftrace_ops * |
| ftrace_find_tramp_ops_new(struct dyn_ftrace *rec) |
| { |
| struct ftrace_ops *op; |
| unsigned long ip = rec->ip; |
| |
| do_for_each_ftrace_op(op, ftrace_ops_list) { |
| /* pass rec in as regs to have non-NULL val */ |
| if (hash_contains_ip(ip, op->func_hash)) |
| return op; |
| } while_for_each_ftrace_op(op); |
| |
| return NULL; |
| } |
| |
| /** |
| * ftrace_get_addr_new - Get the call address to set to |
| * @rec: The ftrace record descriptor |
| * |
| * If the record has the FTRACE_FL_REGS set, that means that it |
| * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS |
| * is not not set, then it wants to convert to the normal callback. |
| * |
| * Returns the address of the trampoline to set to |
| */ |
| unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) |
| { |
| struct ftrace_ops *ops; |
| |
| /* Trampolines take precedence over regs */ |
| if (rec->flags & FTRACE_FL_TRAMP) { |
| ops = ftrace_find_tramp_ops_new(rec); |
| if (FTRACE_WARN_ON(!ops || !ops->trampoline)) { |
| pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n", |
| (void *)rec->ip, (void *)rec->ip, rec->flags); |
| /* Ftrace is shutting down, return anything */ |
| return (unsigned long)FTRACE_ADDR; |
| } |
| return ops->trampoline; |
| } |
| |
| if (rec->flags & FTRACE_FL_REGS) |
| return (unsigned long)FTRACE_REGS_ADDR; |
| else |
| return (unsigned long)FTRACE_ADDR; |
| } |
| |
| /** |
| * ftrace_get_addr_curr - Get the call address that is already there |
| * @rec: The ftrace record descriptor |
| * |
| * The FTRACE_FL_REGS_EN is set when the record already points to |
| * a function that saves all the regs. Basically the '_EN' version |
| * represents the current state of the function. |
| * |
| * Returns the address of the trampoline that is currently being called |
| */ |
| unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) |
| { |
| struct ftrace_ops *ops; |
| |
| /* Trampolines take precedence over regs */ |
| if (rec->flags & FTRACE_FL_TRAMP_EN) { |
| ops = ftrace_find_tramp_ops_curr(rec); |
| if (FTRACE_WARN_ON(!ops)) { |
| pr_warn("Bad trampoline accounting at: %p (%pS)\n", |
| (void *)rec->ip, (void *)rec->ip); |
| /* Ftrace is shutting down, return anything */ |
| return (unsigned long)FTRACE_ADDR; |
| } |
| return ops->trampoline; |
| } |
| |
| if (rec->flags & FTRACE_FL_REGS_EN) |
| return (unsigned long)FTRACE_REGS_ADDR; |
| else |
| return (unsigned long)FTRACE_ADDR; |
| } |
| |
| static int |
| __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
| { |
| unsigned long ftrace_old_addr; |
| unsigned long ftrace_addr; |
| int ret; |
| |
| ftrace_addr = ftrace_get_addr_new(rec); |
| |
| /* This needs to be done before we call ftrace_update_record */ |
| ftrace_old_addr = ftrace_get_addr_curr(rec); |
| |
| ret = ftrace_update_record(rec, enable); |
| |
| ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
| |
| switch (ret) { |
| case FTRACE_UPDATE_IGNORE: |
| return 0; |
| |
| case FTRACE_UPDATE_MAKE_CALL: |
| ftrace_bug_type = FTRACE_BUG_CALL; |
| return ftrace_make_call(rec, ftrace_addr); |
| |
| case FTRACE_UPDATE_MAKE_NOP: |
| ftrace_bug_type = FTRACE_BUG_NOP; |
| return ftrace_make_nop(NULL, rec, ftrace_old_addr); |
| |
| case FTRACE_UPDATE_MODIFY_CALL: |
| ftrace_bug_type = FTRACE_BUG_UPDATE; |
| return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); |
| } |
| |
| return -1; /* unknown ftrace bug */ |
| } |
| |
| void __weak ftrace_replace_code(int mod_flags) |
| { |
| struct dyn_ftrace *rec; |
| struct ftrace_page *pg; |
| int enable = mod_flags & FTRACE_MODIFY_ENABLE_FL; |
| int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL; |
| int failed; |
| |
| if (unlikely(ftrace_disabled)) |
| return; |
| |
| do_for_each_ftrace_rec(pg, rec) { |
| |
| if (rec->flags & FTRACE_FL_DISABLED) |
| continue; |
| |
| failed = __ftrace_replace_code(rec, enable); |
| if (failed) { |
| ftrace_bug(failed, rec); |
| /* Stop processing */ |
| return; |
| } |
| if (schedulable) |
| cond_resched(); |
| } while_for_each_ftrace_rec(); |
| } |
| |
| struct ftrace_rec_iter { |
| struct ftrace_page *pg; |
| int index; |
| }; |
| |
| /** |
| * ftrace_rec_iter_start, start up iterating over traced functions |
| * |
| * Returns an iterator handle that is used to iterate over all |
| * the records that represent address locations where functions |
| * are traced. |
| * |
| * May return NULL if no records are available. |
| */ |
| struct ftrace_rec_iter *ftrace_rec_iter_start(void) |
| { |
| /* |
| * We only use a single iterator. |
| * Protected by the ftrace_lock mutex. |
| */ |
| static struct ftrace_rec_iter ftrace_rec_iter; |
| struct ftrace_rec_iter *iter = &ftrace_rec_iter; |
| |
| iter->pg = ftrace_pages_start; |
| iter->index = 0; |
| |
| /* Could have empty pages */ |
| while (iter->pg && !iter->pg->index) |
| iter->pg = iter->pg->next; |
| |
| if (!iter->pg) |
| return NULL; |
| |
| return iter; |
| } |
| |
| /** |
| * ftrace_rec_iter_next, get the next record to process. |
| * @iter: The handle to the iterator. |
| * |
| * Returns the next iterator after the given iterator @iter. |
| */ |
| struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) |
| { |
| iter->index++; |
| |
| if (iter->index >= iter->pg->index) { |
| iter->pg = iter->pg->next; |
| iter->index = 0; |
| |
| /* Could have empty pages */ |
| while (iter->pg && !iter->pg->index) |
| iter->pg = iter->pg->next; |
| } |
| |
| if (!iter->pg) |
| return NULL; |
| |
| return iter; |
| } |
| |
| /** |
| * ftrace_rec_iter_record, get the record at the iterator location |
| * @iter: The current iterator location |
| * |
| * Returns the record that the current @iter is at. |
| */ |
| struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) |
| { |
| return &iter->pg->records[iter->index]; |
| } |
| |
| static int |
| ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
| { |
| int ret; |
| |
| if (unlikely(ftrace_disabled)) |
| return 0; |
| |
| ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
| if (ret) { |
| ftrace_bug_type = FTRACE_BUG_INIT; |
| ftrace_bug(ret, rec); |
| return 0; |
| } |
| return 1; |
| } |
| |
| /* |
| * archs can override this function if they must do something |
| * before the modifying code is performed. |
| */ |
| int __weak ftrace_arch_code_modify_prepare(void) |
| { |
| return 0; |
| } |
| |
| /* |
| * archs can override this function if they must do something |
| * after the modifying code is performed. |
| */ |
| int __weak ftrace_arch_code_modify_post_process(void) |
| { |
| return 0; |
| } |
| |
| void ftrace_modify_all_code(int command) |
| { |
| int update = command & FTRACE_UPDATE_TRACE_FUNC; |
| int mod_flags = 0; |
| int err = 0; |
| |
| if (command & FTRACE_MAY_SLEEP) |
| mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL; |
| |
| /* |
| * If the ftrace_caller calls a ftrace_ops func directly, |
| * we need to make sure that it only traces functions it |
| * expects to trace. When doing the switch of functions, |
| * we need to update to the ftrace_ops_list_func first |
| * before the transition between old and new calls are set, |
| * as the ftrace_ops_list_func will check the ops hashes |
| * to make sure the ops are having the right functions |
| * traced. |
| */ |
| if (update) { |
| err = ftrace_update_ftrace_func(ftrace_ops_list_func); |
| if (FTRACE_WARN_ON(err)) |
| return; |
| } |
| |
| if (command & FTRACE_UPDATE_CALLS) |
| ftrace_replace_code(mod_flags | FTRACE_MODIFY_ENABLE_FL); |
| else if (command & FTRACE_DISABLE_CALLS) |
| ftrace_replace_code(mod_flags); |
| |
| if (update && ftrace_trace_function != ftrace_ops_list_func) { |
| function_trace_op = set_function_trace_op; |
| smp_wmb(); |
| /* If irqs are disabled, we are in stop machine */ |
| if (!irqs_disabled()) |
| smp_call_function(ftrace_sync_ipi, NULL, 1); |
| err = ftrace_update_ftrace_func(ftrace_trace_function); |
| if (FTRACE_WARN_ON(err)) |
| return; |
| } |
| |
| if (command & FTRACE_START_FUNC_RET) |
| err = ftrace_enable_ftrace_graph_caller(); |
| else if (command & FTRACE_STOP_FUNC_RET) |
| err = ftrace_disable_ftrace_graph_caller(); |
| FTRACE_WARN_ON(err); |
| } |
| |
| static int __ftrace_modify_code(void *data) |
| { |
| int *command = data; |
| |
| ftrace_modify_all_code(*command); |
| |
| return 0; |
| } |
| |
| /** |
| * ftrace_run_stop_machine, go back to the stop machine method |
| * @command: The command to tell ftrace what to do |
| * |
| * If an arch needs to fall back to the stop machine method, the |
| * it can call this function. |
| */ |
| void ftrace_run_stop_machine(int command) |
| { |
| stop_machine(__ftrace_modify_code, &command, NULL); |
| } |
| |
| /** |
| * arch_ftrace_update_code, modify the code to trace or not trace |
| * @command: The command that needs to be done |
| * |
| * Archs can override this function if it does not need to |
| * run stop_machine() to modify code. |
| */ |
| void __weak arch_ftrace_update_code(int command) |
| { |
| ftrace_run_stop_machine(command); |
| } |
| |
| static void ftrace_run_update_code(int command) |
| { |
| int ret; |
| |
| ret = ftrace_arch_code_modify_prepare(); |
| FTRACE_WARN_ON(ret); |
| if (ret) |
| return; |
| |
| /* |
| * By default we use stop_machine() to modify the code. |
| * But archs can do what ever they want as long as it |
| * is safe. The stop_machine() is the safest, but also |
| * produces the most overhead. |
| */ |
| arch_ftrace_update_code(command); |
| |
| ret = ftrace_arch_code_modify_post_process(); |
| FTRACE_WARN_ON(ret); |
| } |
| |
| static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, |
| struct ftrace_ops_hash *old_hash) |
| { |
| ops->flags |= FTRACE_OPS_FL_MODIFYING; |
| ops->old_hash.filter_hash = old_hash->filter_hash; |
| ops->old_hash.notrace_hash = old_hash->notrace_hash; |
| ftrace_run_update_code(command); |
| ops->old_hash.filter_hash = NULL; |
| ops->old_hash.notrace_hash = NULL; |
| ops->flags &= ~FTRACE_OPS_FL_MODIFYING; |
| } |
| |
| static ftrace_func_t saved_ftrace_func; |
| static int ftrace_start_up; |
| |
| void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops) |
| { |
| } |
| |
| static void ftrace_startup_enable(int command) |
| { |
| if (saved_ftrace_func != ftrace_trace_function) { |
| saved_ftrace_func = ftrace_trace_function; |
| command |= FTRACE_UPDATE_TRACE_FUNC; |
| } |
| |
| if (!command || !ftrace_enabled) |
| return; |
| |
| ftrace_run_update_code(command); |
| } |
| |
| static void ftrace_startup_all(int command) |
| { |
| update_all_ops = true; |
| ftrace_startup_enable(command); |
| update_all_ops = false; |
| } |
| |
| int ftrace_startup(struct ftrace_ops *ops, int command) |
| { |
| int ret; |
| |
| if (unlikely(ftrace_disabled)) |
| return -ENODEV; |
| |
| ret = __register_ftrace_function(ops); |
| if (ret) |
| return ret; |
| |
| ftrace_start_up++; |
| |
| /* |
| * Note that ftrace probes uses this to start up |
| * and modify functions it will probe. But we still |
| * set the ADDING flag for modification, as probes |
| * do not have trampolines. If they add them in the |
| * future, then the probes will need to distinguish |
| * between adding and updating probes. |
| */ |
| ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING; |
| |
| ret = ftrace_hash_ipmodify_enable(ops); |
| if (ret < 0) { |
| /* Rollback registration process */ |
| __unregister_ftrace_function(ops); |
| ftrace_start_up--; |
| ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
| return ret; |
| } |
| |
| if (ftrace_hash_rec_enable(ops, 1)) |
| command |= FTRACE_UPDATE_CALLS; |
| |
| ftrace_startup_enable(command); |
| |
| ops->flags &= ~FTRACE_OPS_FL_ADDING; |
| |
| return 0; |
| } |
| |
| int ftrace_shutdown(struct ftrace_ops *ops, int command) |
| { |
| int ret; |
| |
| if (unlikely(ftrace_disabled)) |
| return -ENODEV; |
| |
| ret = __unregister_ftrace_function(ops); |
| if (ret) |
| return ret; |
| |
| ftrace_start_up--; |
| /* |
| * Just warn in case of unbalance, no need to kill ftrace, it's not |
| * critical but the ftrace_call callers may be never nopped again after |
| * further ftrace uses. |
| */ |
| WARN_ON_ONCE(ftrace_start_up < 0); |
| |
| /* Disabling ipmodify never fails */ |
| ftrace_hash_ipmodify_disable(ops); |
| |
| if (ftrace_hash_rec_disable(ops, 1)) |
| command |= FTRACE_UPDATE_CALLS; |
| |
| ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
| |
| if (saved_ftrace_func != ftrace_trace_function) { |
| saved_ftrace_func = ftrace_trace_function; |
| command |= FTRACE_UPDATE_TRACE_FUNC; |
| } |
| |
| if (!command || !ftrace_enabled) { |
| /* |
| * If these are dynamic or per_cpu ops, they still |
| * need their data freed. Since, function tracing is |
| * not currently active, we can just free them |
| * without synchronizing all CPUs. |
| */ |
| if (ops->flags & FTRACE_OPS_FL_DYNAMIC) |
| goto free_ops; |
| |
| return 0; |
| } |
| |
| /* |
| * If the ops uses a trampoline, then it needs to be |
| * tested first on update. |
| */ |
| ops->flags |= FTRACE_OPS_FL_REMOVING; |
| removed_ops = ops; |
| |
| /* The trampoline logic checks the old hashes */ |
| ops->old_hash.filter_hash = ops->func_hash->filter_hash; |
| ops->old_hash.notrace_hash = ops->func_hash->notrace_hash; |
| |
| ftrace_run_update_code(command); |
| |
| /* |
| * If there's no more ops registered with ftrace, run a |
| * sanity check to make sure all rec flags are cleared. |
| */ |
| if (rcu_dereference_protected(ftrace_ops_list, |
| lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { |
| struct ftrace_page *pg; |
| struct dyn_ftrace *rec; |
| |
| do_for_each_ftrace_rec(pg, rec) { |
| if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED)) |
| pr_warn(" %pS flags:%lx\n", |
| (void *)rec->ip, rec->flags); |
| } while_for_each_ftrace_rec(); |
| } |
| |
| ops->old_hash.filter_hash = NULL; |
| ops->old_hash.notrace_hash = NULL; |
| |
| removed_ops = NULL; |
| ops->flags &= ~FTRACE_OPS_FL_REMOVING; |
| |
| /* |
| * Dynamic ops may be freed, we must make sure that all |
| * callers are done before leaving this function. |
| * The same goes for freeing the per_cpu data of the per_cpu |
| * ops. |
| */ |
| if (ops->flags & FTRACE_OPS_FL_DYNAMIC) { |
| /* |
| * We need to do a hard force of sched synchronization. |
| * This is because we use preempt_disable() to do RCU, but |
| * the function tracers can be called where RCU is not watching |
| * (like before user_exit()). We can not rely on the RCU |
| * infrastructure to do the synchronization, thus we must do it |
| * ourselves. |
| */ |
| schedule_on_each_cpu(ftrace_sync); |
| |
| /* |
| * When the kernel is preeptive, tasks can be preempted |
| * while on a ftrace trampoline. Just scheduling a task on |
| * a CPU is not good enough to flush them. Calling |
| * synchornize_rcu_tasks() will wait for those tasks to |
| * execute and either schedule voluntarily or enter user space. |
| */ |
| if (IS_ENABLED(CONFIG_PREEMPT)) |
| synchronize_rcu_tasks(); |
| |
| free_ops: |
| arch_ftrace_trampoline_free(ops); |
| } |
| |
| return 0; |
| } |
| |
| static void ftrace_startup_sysctl(void) |
| { |
| int command; |
| |
| if (unlikely(ftrace_disabled)) |
| return; |
| |
| /* Force update next time */ |
| saved_ftrace_func = NULL; |
| /* ftrace_start_up is true if we want ftrace running */ |
| if (ftrace_start_up) { |
| command = FTRACE_UPDATE_CALLS; |
| if (ftrace_graph_active) |
| command |= FTRACE_START_FUNC_RET; |
| ftrace_startup_enable(command); |
| } |
| } |
| |
| static void ftrace_shutdown_sysctl(void) |
| { |
| int command; |
| |
| if (unlikely(ftrace_disabled)) |
| return; |
| |
| /* ftrace_start_up is true if ftrace is running */ |
| if (ftrace_start_up) { |
| command = FTRACE_DISABLE_CALLS; |
| if (ftrace_graph_active) |
| command |= FTRACE_STOP_FUNC_RET; |
| ftrace_run_update_code(command); |
| } |
| } |
| |
| static u64 ftrace_update_time; |
| unsigned long ftrace_update_tot_cnt; |
| |
| static inline int ops_traces_mod(struct ftrace_ops *ops) |
| { |
| /* |
| * Filter_hash being empty will default to trace module. |
| * But notrace hash requires a test of individual module functions. |
| */ |
| return ftrace_hash_empty(ops->func_hash->filter_hash) && |
| ftrace_hash_empty(ops->func_hash->notrace_hash); |
| } |
| |
| /* |
| * Check if the current ops references the record. |
| * |
| * If the ops traces all functions, then it was already accounted for. |
| * If the ops does not trace the current record function, skip it. |
| * If the ops ignores the function via notrace filter, skip it. |
| */ |
| static inline bool |
| ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec) |
| { |
| /* If ops isn't enabled, ignore it */ |
| if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) |
| return false; |
| |
| /* If ops traces all then it includes this function */ |
| if (ops_traces_mod(ops)) |
| return true; |
| |
| /* The function must be in the filter */ |
| if (!ftrace_hash_empty(ops->func_hash->filter_hash) && |
| !__ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip)) |
| return false; |
| |
| /* If in notrace hash, we ignore it too */ |
| if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) |
| return false; |
| |
| return true; |
| } |
| |
| static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) |
| { |
| struct ftrace_page *pg; |
| struct dyn_ftrace *p; |
| u64 start, stop; |
| unsigned long update_cnt = 0; |
| unsigned long rec_flags = 0; |
| int i; |
| |
| start = ftrace_now(raw_smp_processor_id()); |
| |
| /* |
| * When a module is loaded, this function is called to convert |
| * the calls to mcount in its text to nops, and also to create |
| * an entry in the ftrace data. Now, if ftrace is activated |
| * after this call, but before the module sets its text to |
| * read-only, the modification of enabling ftrace can fail if |
| * the read-only is done while ftrace is converting the calls. |
| * To prevent this, the module's records are set as disabled |
| * and will be enabled after the call to set the module's text |
| * to read-only. |
| */ |
| if (mod) |
| rec_flags |= FTRACE_FL_DISABLED; |
| |
| for (pg = new_pgs; pg; pg = pg->next) { |
| |
| for (i = 0; i < pg->index; i++) { |
| |
| /* If something went wrong, bail without enabling anything */ |
| if (unlikely(ftrace_disabled)) |
| return -1; |
| |
| p = &pg->records[i]; |
| p->flags = rec_flags; |
| |
| #ifndef CC_USING_NOP_MCOUNT |
| /* |
| * Do the initial record conversion from mcount jump |
| * to the NOP instructions. |
| */ |
| if (!ftrace_code_disable(mod, p)) |
| break; |
| #endif |
| |
| update_cnt++; |
| } |
| } |
| |
| stop = ftrace_now(raw_smp_processor_id()); |
| ftrace_update_time = stop - start; |
| ftrace_update_tot_cnt += update_cnt; |
| |
| return 0; |
| } |
| |
| static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
| { |
| int order; |
| int cnt; |
| |
| if (WARN_ON(!count)) |
| return -EINVAL; |
| |
| order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); |
| |
| /* |
| * We want to fill as much as possible. No more than a page |
| * may be empty. |
| */ |
| while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) |
| order--; |
| |
| again: |
| pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); |
| |
| if (!pg->records) { |
| /* if we can't allocate this size, try something smaller */ |
| if (!order) |
| return -ENOMEM; |
| order >>= 1; |
| goto again; |
| } |
| |
| cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
| pg->size = cnt; |
| |
| if (cnt > count) |
| cnt = count; |
| |
| return cnt; |
| } |
| |
| static struct ftrace_page * |
| ftrace_allocate_pages(unsigned long num_to_init) |
| { |
| struct ftrace_page *start_pg; |
| struct ftrace_page *pg; |
| int order; |
| int cnt; |
| |
| if (!num_to_init) |
| return NULL; |
| |
| start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); |
| if (!pg) |
| return NULL; |
| |
| /* |
| * Try to allocate as much as possible in one continues |
| * location that fills in all of the space. We want to |
| * waste as little space as possible. |
| */ |
| for (;;) { |
| cnt = ftrace_allocate_records(pg, num_to_init); |
| if (cnt < 0) |
| goto free_pages; |
| |
| num_to_init -= cnt; |
| if (!num_to_init) |
| break; |
| |
| pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
| if (!pg->next) |
| goto free_pages; |
| |
| pg = pg->next; |
| } |
| |
| return start_pg; |
| |
| free_pages: |
| pg = start_pg; |
| while (pg) { |
| order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
| free_pages((unsigned long)pg->records, order); |
| start_pg = pg->next; |
| kfree(pg); |
| pg = start_pg; |
| } |
| pr_info("ftrace: FAILED to allocate memory for functions\n"); |
| return NULL; |
| } |
| |
| #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
| |
| struct ftrace_iterator { |
| loff_t pos; |
| loff_t func_pos; |
| loff_t mod_pos; |
| struct ftrace_page *pg; |
| struct dyn_ftrace *func; |
| struct ftrace_func_probe *probe; |
| struct ftrace_func_entry *probe_entry; |
| struct trace_parser parser; |
| struct ftrace_hash *hash; |
| struct ftrace_ops *ops; |
| struct trace_array *tr; |
| struct list_head *mod_list; |
| int pidx; |
| int idx; |
| unsigned flags; |
| }; |
| |
| static void * |
| t_probe_next(struct seq_file *m, loff_t *pos) |
| { |
| struct ftrace_iterator *iter = m->private; |
| struct trace_array *tr = iter->ops->private; |
| struct list_head *func_probes; |
| struct ftrace_hash *hash; |
| struct list_head *next; |
| struct hlist_node *hnd = NULL; |
| struct hlist_head *hhd; |
| int size; |
| |
| (*pos)++; |
| iter->pos = *pos; |
| |
| if (!tr) |
| return NULL; |
| |
| func_probes = &tr->func_probes; |
| if (list_empty(func_probes)) |
| return NULL; |
| |
| if (!iter->probe) { |
| next = func_probes->next; |
| iter->probe = list_entry(next, struct ftrace_func_probe, list); |
| } |
| |
| if (iter->probe_entry) |
| hnd = &iter->probe_entry->hlist; |
| |
| hash = iter->probe->ops.func_hash->filter_hash; |
| size = 1 << hash->size_bits; |
| |
| retry: |
| if (iter->pidx >= size) { |
| if (iter->probe->list.next == func_probes) |
| return NULL; |
| next = iter->probe->list.next; |
| iter->probe = list_entry(next, struct ftrace_func_probe, list); |
| hash = iter->probe->ops.func_hash->filter_hash; |
| size = 1 << hash->size_bits; |
| iter->pidx = 0; |
| } |
| |
| hhd = &hash->buckets[iter->pidx]; |
| |
| if (hlist_empty(hhd)) { |
| iter->pidx++; |
| hnd = NULL; |
| goto retry; |
| } |
| |
| if (!hnd) |
| hnd = hhd->first; |
| else { |
| hnd = hnd->next; |
| if (!hnd) { |
| iter->pidx++; |
| goto retry; |
| } |
| } |
| |
| if (WARN_ON_ONCE(!hnd)) |
| return NULL; |
| |
| iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist); |
| |
| return iter; |
| } |
| |
| static void *t_probe_start(struct seq_file *m, loff_t *pos) |
| { |
| struct ftrace_iterator *iter = m->private; |
| void *p = NULL; |
| loff_t l; |
| |
| if (!(iter->flags & FTRACE_ITER_DO_PROBES)) |
| return NULL; |
| |
| if (iter->mod_pos > *pos) |
| return NULL; |
| |
| iter->probe = NULL; |
| iter->probe_entry = NULL; |
| iter->pidx = 0; |
| for (l = 0; l <= (*pos - iter->mod_pos); ) { |
| p = t_probe_next(m, &l); |
| if (!p) |
| break; |
| } |
| if (!p) |
| return NULL; |
| |
| /* Only set this if we have an item */ |
| iter->flags |= FTRACE_ITER_PROBE; |
| |
| return iter; |
| } |
| |
| static int |
| t_probe_show(struct seq_file *m, struct ftrace_iterator *iter) |
| { |
| struct ftrace_func_entry *probe_entry; |
| struct ftrace_probe_ops *probe_ops; |
| struct ftrace_func_probe *probe; |
| |
| probe = iter->probe; |
| probe_entry = iter->probe_entry; |
| |
| if (WARN_ON_ONCE(!probe || !probe_entry)) |
| return -EIO; |
| |
| probe_ops = probe->probe_ops; |
| |
| if (probe_ops->print) |
| return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data); |
| |
| seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip, |
| (void *)probe_ops->func); |
| |
| return 0; |
| } |
| |
| static void * |
| t_mod_next(struct seq_file *m, loff_t *pos) |
| { |
| struct ftrace_iterator *iter = m->private; |
| struct trace_array *tr = iter->tr; |
| |
| (*pos)++; |
| iter->pos = *pos; |
| |
| iter->mod_list = iter->mod_list->next; |
| |
| if (iter->mod_list == &tr->mod_trace || |
| iter->mod_list == &tr->mod_notrace) { |
| iter->flags &= ~FTRACE_ITER_MOD; |
| return NULL; |
| } |
| |
| iter->mod_pos = *pos; |
| |
| return iter; |
| } |
| |
| static void *t_mod_start(struct seq_file *m, loff_t *pos) |
| { |
| struct ftrace_iterator *iter = m->private; |
| void *p = NULL; |
| loff_t l; |
| |
| if (iter->func_pos > *pos) |
| return NULL; |
| |
| iter->mod_pos = iter->func_pos; |
| |
| /* probes are only available if tr is set */ |
| if (!iter->tr) |
| return NULL; |
| |
| for (l = 0; l <= (*pos - iter->func_pos); ) { |
| p = t_mod_next(m, &l); |
| if (!p) |
| break; |
| } |
| if (!p) { |
| iter->flags &= ~FTRACE_ITER_MOD; |
| return t_probe_start(m, pos); |
| } |
| |
| /* Only set this if we have an item */ |
| iter->flags |= FTRACE_ITER_MOD; |
| |
| return iter; |
| } |
| |
| static int |
| t_mod_show(struct seq_file *m, struct ftrace_iterator *iter) |
| { |
| struct ftrace_mod_load *ftrace_mod; |
| struct trace_array *tr = iter->tr; |
| |
| if (WARN_ON_ONCE(!iter->mod_list) || |
| iter->mod_list == &tr->mod_trace || |
| iter->mod_list == &tr->mod_notrace) |
| return -EIO; |
| |
| ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list); |
| |
| if (ftrace_mod->func) |
| seq_printf(m, "%s", ftrace_mod->func); |
| else |
| seq_putc(m, '*'); |
| |
| seq_printf(m, ":mod:%s\n", ftrace_mod->module); |
| |
| return 0; |
| } |
| |
| static void * |
| t_func_next(struct seq_file *m, loff_t *pos) |
| { |
| struct ftrace_iterator *iter = m->private; |
| struct dyn_ftrace *rec = NULL; |
| |
| (*pos)++; |
| |
| retry: |
| if (iter->idx >= iter->pg->index) { |
| if (iter->pg->next) { |
| iter->pg = iter->pg->next; |
| iter->idx = 0; |
| goto retry; |
| } |
| } else { |
| rec = &iter->pg->records[iter->idx++]; |
| if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
| !ftrace_lookup_ip(iter->hash, rec->ip)) || |
| |
| ((iter->flags & FTRACE_ITER_ENABLED) && |
| !(rec->flags & FTRACE_FL_ENABLED))) { |
| |
| rec = NULL; |
| goto retry; |
| } |
| } |
| |
| if (!rec) |
| return NULL; |
| |
| iter->pos = iter->func_pos = *pos; |
| iter->func = rec; |
| |
| return iter; |
| } |
| |
| static void * |
| t_next(struct seq_file *m, void *v, loff_t *pos) |
| { |
| struct ftrace_iterator *iter = m->private; |
| loff_t l = *pos; /* t_probe_start() must use original pos */ |
| void *ret; |
| |
| if (unlikely(ftrace_disabled)) |
| return NULL; |
| |
| if (iter->flags & FTRACE_ITER_PROBE) |
| return t_probe_next(m, pos); |
| |
| if (iter->flags & FTRACE_ITER_MOD) |
| return t_mod_next(m, pos); |
| |
| if (iter->flags & FTRACE_ITER_PRINTALL) { |
| /* next must increment pos, and t_probe_start does not */ |
| (*pos)++; |
| return t_mod_start(m, &l); |
| } |
| |
| ret = t_func_next(m, pos); |
| |
| if (!ret) |
| return t_mod_start(m, &l); |
| |
| return ret; |
| } |
| |
| static void reset_iter_read(struct ftrace_iterator *iter) |
| { |
| iter->pos = 0; |
| iter->func_pos = 0; |
|