diff options
Diffstat (limited to 'kernel/trace/ftrace.c')
| -rw-r--r-- | kernel/trace/ftrace.c | 113 |
1 files changed, 109 insertions, 4 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index c163c3531faf..72064541bef2 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2260,7 +2260,7 @@ ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, if (hash_contains_ip(ip, op->func_hash)) return op; - } + } return NULL; } @@ -2764,6 +2764,50 @@ void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops) { } +/* List of trace_ops that have allocated trampolines */ +static LIST_HEAD(ftrace_ops_trampoline_list); + +static void ftrace_add_trampoline_to_kallsyms(struct ftrace_ops *ops) +{ + lockdep_assert_held(&ftrace_lock); + list_add_rcu(&ops->list, &ftrace_ops_trampoline_list); +} + +static void ftrace_remove_trampoline_from_kallsyms(struct ftrace_ops *ops) +{ + lockdep_assert_held(&ftrace_lock); + list_del_rcu(&ops->list); +} + +/* + * "__builtin__ftrace" is used as a module name in /proc/kallsyms for symbols + * for pages allocated for ftrace purposes, even though "__builtin__ftrace" is + * not a module. + */ +#define FTRACE_TRAMPOLINE_MOD "__builtin__ftrace" +#define FTRACE_TRAMPOLINE_SYM "ftrace_trampoline" + +static void ftrace_trampoline_free(struct ftrace_ops *ops) +{ + if (ops && (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP) && + ops->trampoline) { + /* + * Record the text poke event before the ksymbol unregister + * event. + */ + perf_event_text_poke((void *)ops->trampoline, + (void *)ops->trampoline, + ops->trampoline_size, NULL, 0); + perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, + ops->trampoline, ops->trampoline_size, + true, FTRACE_TRAMPOLINE_SYM); + /* Remove from kallsyms after the perf events */ + ftrace_remove_trampoline_from_kallsyms(ops); + } + + arch_ftrace_trampoline_free(ops); +} + static void ftrace_startup_enable(int command) { if (saved_ftrace_func != ftrace_trace_function) { @@ -2934,7 +2978,7 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command) synchronize_rcu_tasks(); free_ops: - arch_ftrace_trampoline_free(ops); + ftrace_trampoline_free(ops); } return 0; @@ -3599,7 +3643,7 @@ static int t_show(struct seq_file *m, void *v) if (direct) seq_printf(m, "\n\tdirect-->%pS", (void *)direct); } - } + } seq_putc(m, '\n'); @@ -6178,6 +6222,27 @@ struct ftrace_mod_map { unsigned int num_funcs; }; +static int ftrace_get_trampoline_kallsym(unsigned int symnum, + unsigned long *value, char *type, + char *name, char *module_name, + int *exported) +{ + struct ftrace_ops *op; + + list_for_each_entry_rcu(op, &ftrace_ops_trampoline_list, list) { + if (!op->trampoline || symnum--) + continue; + *value = op->trampoline; + *type = 't'; + strlcpy(name, FTRACE_TRAMPOLINE_SYM, KSYM_NAME_LEN); + strlcpy(module_name, FTRACE_TRAMPOLINE_MOD, MODULE_NAME_LEN); + *exported = 0; + return 0; + } + + return -ERANGE; +} + #ifdef CONFIG_MODULES #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) @@ -6514,6 +6579,7 @@ int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, { struct ftrace_mod_map *mod_map; struct ftrace_mod_func *mod_func; + int ret; preempt_disable(); list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { @@ -6540,8 +6606,10 @@ int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, WARN_ON(1); break; } + ret = ftrace_get_trampoline_kallsym(symnum, value, type, name, + module_name, exported); preempt_enable(); - return -ERANGE; + return ret; } #else @@ -6553,6 +6621,18 @@ allocate_ftrace_mod_map(struct module *mod, { return NULL; } +int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, + char *type, char *name, char *module_name, + int *exported) +{ + int ret; + + preempt_disable(); + ret = ftrace_get_trampoline_kallsym(symnum, value, type, name, + module_name, exported); + preempt_enable(); + return ret; +} #endif /* CONFIG_MODULES */ struct ftrace_init_func { @@ -6733,7 +6813,24 @@ void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops) static void ftrace_update_trampoline(struct ftrace_ops *ops) { + unsigned long trampoline = ops->trampoline; + arch_ftrace_update_trampoline(ops); + if (ops->trampoline && ops->trampoline != trampoline && + (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP)) { + /* Add to kallsyms before the perf events */ + ftrace_add_trampoline_to_kallsyms(ops); + perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, + ops->trampoline, ops->trampoline_size, false, + FTRACE_TRAMPOLINE_SYM); + /* + * Record the perf text poke event after the ksymbol register + * event. + */ + perf_event_text_poke((void *)ops->trampoline, NULL, 0, + (void *)ops->trampoline, + ops->trampoline_size); + } } void ftrace_init_trace_array(struct trace_array *tr) @@ -7151,6 +7248,10 @@ static int pid_open(struct inode *inode, struct file *file, int type) case TRACE_NO_PIDS: seq_ops = &ftrace_no_pid_sops; break; + default: + trace_array_put(tr); + WARN_ON_ONCE(1); + return -EINVAL; } ret = seq_open(file, seq_ops); @@ -7229,6 +7330,10 @@ pid_write(struct file *filp, const char __user *ubuf, other_pids = rcu_dereference_protected(tr->function_pids, lockdep_is_held(&ftrace_lock)); break; + default: + ret = -EINVAL; + WARN_ON_ONCE(1); + goto out; } ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt); |