diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/trampoline.c | 259 | ||||
| -rw-r--r-- | kernel/trace/Kconfig | 3 | ||||
| -rw-r--r-- | kernel/trace/ftrace.c | 406 |
3 files changed, 597 insertions, 71 deletions
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index edf9da43762d..952cd7932461 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -24,19 +24,49 @@ const struct bpf_prog_ops bpf_extension_prog_ops = { #define TRAMPOLINE_HASH_BITS 10 #define TRAMPOLINE_TABLE_SIZE (1 << TRAMPOLINE_HASH_BITS) -static struct hlist_head trampoline_table[TRAMPOLINE_TABLE_SIZE]; +static struct hlist_head trampoline_key_table[TRAMPOLINE_TABLE_SIZE]; +static struct hlist_head trampoline_ip_table[TRAMPOLINE_TABLE_SIZE]; -/* serializes access to trampoline_table */ +/* serializes access to trampoline tables */ static DEFINE_MUTEX(trampoline_mutex); #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mutex); -static int bpf_tramp_ftrace_ops_func(struct ftrace_ops *ops, enum ftrace_ops_cmd cmd) +#ifdef CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS +static struct bpf_trampoline *direct_ops_ip_lookup(struct ftrace_ops *ops, unsigned long ip) { - struct bpf_trampoline *tr = ops->private; + struct hlist_head *head_ip; + struct bpf_trampoline *tr; + + mutex_lock(&trampoline_mutex); + head_ip = &trampoline_ip_table[hash_64(ip, TRAMPOLINE_HASH_BITS)]; + hlist_for_each_entry(tr, head_ip, hlist_ip) { + if (tr->ip == ip) + goto out; + } + tr = NULL; +out: + mutex_unlock(&trampoline_mutex); + return tr; +} +#else +static struct bpf_trampoline *direct_ops_ip_lookup(struct ftrace_ops *ops, unsigned long ip) +{ + return ops->private; +} +#endif /* CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS */ + +static int bpf_tramp_ftrace_ops_func(struct ftrace_ops *ops, unsigned long ip, + enum ftrace_ops_cmd cmd) +{ + struct bpf_trampoline *tr; int ret = 0; + tr = direct_ops_ip_lookup(ops, ip); + if (!tr) + return -EINVAL; + if (cmd == FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF) { /* This is called inside register_ftrace_direct_multi(), so * tr->mutex is already locked. @@ -142,15 +172,171 @@ void bpf_image_ksym_del(struct bpf_ksym *ksym) PAGE_SIZE, true, ksym->name); } -static struct bpf_trampoline *bpf_trampoline_lookup(u64 key) +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS +#ifdef CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS +/* + * We have only single direct_ops which contains all the direct call + * sites and is the only global ftrace_ops for all trampolines. + * + * We use 'update_ftrace_direct_*' api for attachment. + */ +struct ftrace_ops direct_ops = { + .ops_func = bpf_tramp_ftrace_ops_func, +}; + +static int direct_ops_alloc(struct bpf_trampoline *tr) +{ + tr->fops = &direct_ops; + return 0; +} + +static void direct_ops_free(struct bpf_trampoline *tr) { } + +static struct ftrace_hash *hash_from_ip(struct bpf_trampoline *tr, void *ptr) +{ + unsigned long ip, addr = (unsigned long) ptr; + struct ftrace_hash *hash; + + ip = ftrace_location(tr->ip); + if (!ip) + return NULL; + hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); + if (!hash) + return NULL; + if (bpf_trampoline_use_jmp(tr->flags)) + addr = ftrace_jmp_set(addr); + if (!add_ftrace_hash_entry_direct(hash, ip, addr)) { + free_ftrace_hash(hash); + return NULL; + } + return hash; +} + +static int direct_ops_add(struct bpf_trampoline *tr, void *addr) +{ + struct ftrace_hash *hash = hash_from_ip(tr, addr); + int err; + + if (!hash) + return -ENOMEM; + err = update_ftrace_direct_add(tr->fops, hash); + free_ftrace_hash(hash); + return err; +} + +static int direct_ops_del(struct bpf_trampoline *tr, void *addr) +{ + struct ftrace_hash *hash = hash_from_ip(tr, addr); + int err; + + if (!hash) + return -ENOMEM; + err = update_ftrace_direct_del(tr->fops, hash); + free_ftrace_hash(hash); + return err; +} + +static int direct_ops_mod(struct bpf_trampoline *tr, void *addr, bool lock_direct_mutex) +{ + struct ftrace_hash *hash = hash_from_ip(tr, addr); + int err; + + if (!hash) + return -ENOMEM; + err = update_ftrace_direct_mod(tr->fops, hash, lock_direct_mutex); + free_ftrace_hash(hash); + return err; +} +#else +/* + * We allocate ftrace_ops object for each trampoline and it contains + * call site specific for that trampoline. + * + * We use *_ftrace_direct api for attachment. + */ +static int direct_ops_alloc(struct bpf_trampoline *tr) +{ + tr->fops = kzalloc(sizeof(struct ftrace_ops), GFP_KERNEL); + if (!tr->fops) + return -ENOMEM; + tr->fops->private = tr; + tr->fops->ops_func = bpf_tramp_ftrace_ops_func; + return 0; +} + +static void direct_ops_free(struct bpf_trampoline *tr) +{ + if (!tr->fops) + return; + ftrace_free_filter(tr->fops); + kfree(tr->fops); +} + +static int direct_ops_add(struct bpf_trampoline *tr, void *ptr) +{ + unsigned long addr = (unsigned long) ptr; + struct ftrace_ops *ops = tr->fops; + int ret; + + if (bpf_trampoline_use_jmp(tr->flags)) + addr = ftrace_jmp_set(addr); + + ret = ftrace_set_filter_ip(ops, tr->ip, 0, 1); + if (ret) + return ret; + return register_ftrace_direct(ops, addr); +} + +static int direct_ops_del(struct bpf_trampoline *tr, void *addr) +{ + return unregister_ftrace_direct(tr->fops, (long)addr, false); +} + +static int direct_ops_mod(struct bpf_trampoline *tr, void *ptr, bool lock_direct_mutex) +{ + unsigned long addr = (unsigned long) ptr; + struct ftrace_ops *ops = tr->fops; + + if (bpf_trampoline_use_jmp(tr->flags)) + addr = ftrace_jmp_set(addr); + if (lock_direct_mutex) + return modify_ftrace_direct(ops, addr); + return modify_ftrace_direct_nolock(ops, addr); +} +#endif /* CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS */ +#else +static void direct_ops_free(struct bpf_trampoline *tr) { } + +static int direct_ops_alloc(struct bpf_trampoline *tr) +{ + return 0; +} + +static int direct_ops_add(struct bpf_trampoline *tr, void *addr) +{ + return -ENODEV; +} + +static int direct_ops_del(struct bpf_trampoline *tr, void *addr) +{ + return -ENODEV; +} + +static int direct_ops_mod(struct bpf_trampoline *tr, void *ptr, bool lock_direct_mutex) +{ + return -ENODEV; +} +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ + +static struct bpf_trampoline *bpf_trampoline_lookup(u64 key, unsigned long ip) { struct bpf_trampoline *tr; struct hlist_head *head; int i; mutex_lock(&trampoline_mutex); - head = &trampoline_table[hash_64(key, TRAMPOLINE_HASH_BITS)]; - hlist_for_each_entry(tr, head, hlist) { + head = &trampoline_key_table[hash_64(key, TRAMPOLINE_HASH_BITS)]; + hlist_for_each_entry(tr, head, hlist_key) { if (tr->key == key) { refcount_inc(&tr->refcnt); goto out; @@ -159,20 +345,19 @@ static struct bpf_trampoline *bpf_trampoline_lookup(u64 key) tr = kzalloc(sizeof(*tr), GFP_KERNEL); if (!tr) goto out; -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS - tr->fops = kzalloc(sizeof(struct ftrace_ops), GFP_KERNEL); - if (!tr->fops) { + if (direct_ops_alloc(tr)) { kfree(tr); tr = NULL; goto out; } - tr->fops->private = tr; - tr->fops->ops_func = bpf_tramp_ftrace_ops_func; -#endif tr->key = key; - INIT_HLIST_NODE(&tr->hlist); - hlist_add_head(&tr->hlist, head); + tr->ip = ftrace_location(ip); + INIT_HLIST_NODE(&tr->hlist_key); + INIT_HLIST_NODE(&tr->hlist_ip); + hlist_add_head(&tr->hlist_key, head); + head = &trampoline_ip_table[hash_64(tr->ip, TRAMPOLINE_HASH_BITS)]; + hlist_add_head(&tr->hlist_ip, head); refcount_set(&tr->refcnt, 1); mutex_init(&tr->mutex); for (i = 0; i < BPF_TRAMP_MAX; i++) @@ -207,7 +392,7 @@ static int unregister_fentry(struct bpf_trampoline *tr, u32 orig_flags, int ret; if (tr->func.ftrace_managed) - ret = unregister_ftrace_direct(tr->fops, (long)old_addr, false); + ret = direct_ops_del(tr, old_addr); else ret = bpf_trampoline_update_fentry(tr, orig_flags, old_addr, NULL); @@ -221,10 +406,7 @@ static int modify_fentry(struct bpf_trampoline *tr, u32 orig_flags, int ret; if (tr->func.ftrace_managed) { - if (lock_direct_mutex) - ret = modify_ftrace_direct(tr->fops, (long)new_addr); - else - ret = modify_ftrace_direct_nolock(tr->fops, (long)new_addr); + ret = direct_ops_mod(tr, new_addr, lock_direct_mutex); } else { ret = bpf_trampoline_update_fentry(tr, orig_flags, old_addr, new_addr); @@ -247,10 +429,7 @@ static int register_fentry(struct bpf_trampoline *tr, void *new_addr) } if (tr->func.ftrace_managed) { - ret = ftrace_set_filter_ip(tr->fops, (unsigned long)ip, 0, 1); - if (ret) - return ret; - ret = register_ftrace_direct(tr->fops, (long)new_addr); + ret = direct_ops_add(tr, new_addr); } else { ret = bpf_trampoline_update_fentry(tr, 0, NULL, new_addr); } @@ -506,13 +685,6 @@ again: if (err) goto out_free; -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_JMP - if (bpf_trampoline_use_jmp(tr->flags)) - tr->fops->flags |= FTRACE_OPS_FL_JMP; - else - tr->fops->flags &= ~FTRACE_OPS_FL_JMP; -#endif - WARN_ON(tr->cur_image && total == 0); if (tr->cur_image) /* progs already running at this address */ @@ -540,15 +712,8 @@ again: tr->cur_image = im; out: /* If any error happens, restore previous flags */ - if (err) { + if (err) tr->flags = orig_flags; -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_JMP - if (bpf_trampoline_use_jmp(tr->flags)) - tr->fops->flags |= FTRACE_OPS_FL_JMP; - else - tr->fops->flags &= ~FTRACE_OPS_FL_JMP; -#endif - } kfree(tlinks); return err; @@ -887,7 +1052,7 @@ void bpf_trampoline_unlink_cgroup_shim(struct bpf_prog *prog) prog->aux->attach_btf_id); bpf_lsm_find_cgroup_shim(prog, &bpf_func); - tr = bpf_trampoline_lookup(key); + tr = bpf_trampoline_lookup(key, 0); if (WARN_ON_ONCE(!tr)) return; @@ -907,7 +1072,7 @@ struct bpf_trampoline *bpf_trampoline_get(u64 key, { struct bpf_trampoline *tr; - tr = bpf_trampoline_lookup(key); + tr = bpf_trampoline_lookup(key, tgt_info->tgt_addr); if (!tr) return NULL; @@ -943,11 +1108,9 @@ void bpf_trampoline_put(struct bpf_trampoline *tr) * fexit progs. The fentry-only trampoline will be freed via * multiple rcu callbacks. */ - hlist_del(&tr->hlist); - if (tr->fops) { - ftrace_free_filter(tr->fops); - kfree(tr->fops); - } + hlist_del(&tr->hlist_key); + hlist_del(&tr->hlist_ip); + direct_ops_free(tr); kfree(tr); out: mutex_unlock(&trampoline_mutex); @@ -1216,7 +1379,9 @@ static int __init init_trampolines(void) int i; for (i = 0; i < TRAMPOLINE_TABLE_SIZE; i++) - INIT_HLIST_HEAD(&trampoline_table[i]); + INIT_HLIST_HEAD(&trampoline_key_table[i]); + for (i = 0; i < TRAMPOLINE_TABLE_SIZE; i++) + INIT_HLIST_HEAD(&trampoline_ip_table[i]); return 0; } late_initcall(init_trampolines); diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index bfa2ec46e075..d7042a09fe46 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -50,6 +50,9 @@ config HAVE_DYNAMIC_FTRACE_WITH_REGS config HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS bool +config HAVE_SINGLE_FTRACE_DIRECT_OPS + bool + config HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS bool diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index ef2d5dca6f70..8574932e66b6 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -68,7 +68,6 @@ }) /* hash bits for specific function selection */ -#define FTRACE_HASH_DEFAULT_BITS 10 #define FTRACE_HASH_MAX_BITS 12 #ifdef CONFIG_DYNAMIC_FTRACE @@ -1211,8 +1210,8 @@ static void __add_hash_entry(struct ftrace_hash *hash, hash->count++; } -static struct ftrace_func_entry * -add_hash_entry(struct ftrace_hash *hash, unsigned long ip) +struct ftrace_func_entry * +add_ftrace_hash_entry_direct(struct ftrace_hash *hash, unsigned long ip, unsigned long direct) { struct ftrace_func_entry *entry; @@ -1221,11 +1220,18 @@ add_hash_entry(struct ftrace_hash *hash, unsigned long ip) return NULL; entry->ip = ip; + entry->direct = direct; __add_hash_entry(hash, entry); return entry; } +static struct ftrace_func_entry * +add_hash_entry(struct ftrace_hash *hash, unsigned long ip) +{ + return add_ftrace_hash_entry_direct(hash, ip, 0); +} + static void free_hash_entry(struct ftrace_hash *hash, struct ftrace_func_entry *entry) @@ -1284,7 +1290,7 @@ static void clear_ftrace_mod_list(struct list_head *head) mutex_unlock(&ftrace_lock); } -static void free_ftrace_hash(struct ftrace_hash *hash) +void free_ftrace_hash(struct ftrace_hash *hash) { if (!hash || hash == EMPTY_HASH) return; @@ -1324,7 +1330,7 @@ void ftrace_free_filter(struct ftrace_ops *ops) } EXPORT_SYMBOL_GPL(ftrace_free_filter); -static struct ftrace_hash *alloc_ftrace_hash(int size_bits) +struct ftrace_hash *alloc_ftrace_hash(int size_bits) { struct ftrace_hash *hash; int size; @@ -1398,7 +1404,7 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) size = 1 << hash->size_bits; for (i = 0; i < size; i++) { hlist_for_each_entry(entry, &hash->buckets[i], hlist) { - if (add_hash_entry(new_hash, entry->ip) == NULL) + if (add_ftrace_hash_entry_direct(new_hash, entry->ip, entry->direct) == NULL) goto free_hash; } } @@ -2069,7 +2075,7 @@ static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops, */ if (!ops->ops_func) return -EBUSY; - ret = ops->ops_func(ops, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF); + ret = ops->ops_func(ops, rec->ip, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF); if (ret) return ret; } else if (is_ipmodify) { @@ -2625,8 +2631,13 @@ unsigned long ftrace_find_rec_direct(unsigned long ip) static void call_direct_funcs(unsigned long ip, unsigned long pip, struct ftrace_ops *ops, struct ftrace_regs *fregs) { - unsigned long addr = READ_ONCE(ops->direct_call); + unsigned long addr; +#ifdef CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS + addr = ftrace_find_rec_direct(ip); +#else + addr = READ_ONCE(ops->direct_call); +#endif if (!addr) return; @@ -6046,15 +6057,8 @@ int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) if (ftrace_hash_empty(hash)) return -EINVAL; - /* This is a "raw" address, and this should never happen. */ - if (WARN_ON_ONCE(ftrace_is_jmp(addr))) - return -EINVAL; - mutex_lock(&direct_mutex); - if (ops->flags & FTRACE_OPS_FL_JMP) - addr = ftrace_jmp_set(addr); - /* Make sure requested entries are not already registered.. */ size = 1 << hash->size_bits; for (i = 0; i < size; i++) { @@ -6175,13 +6179,6 @@ __modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) lockdep_assert_held_once(&direct_mutex); - /* This is a "raw" address, and this should never happen. */ - if (WARN_ON_ONCE(ftrace_is_jmp(addr))) - return -EINVAL; - - if (ops->flags & FTRACE_OPS_FL_JMP) - addr = ftrace_jmp_set(addr); - /* Enable the tmp_ops to have the same functions as the direct ops */ ftrace_ops_init(&tmp_ops); tmp_ops.func_hash = ops->func_hash; @@ -6286,6 +6283,367 @@ int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) return err; } EXPORT_SYMBOL_GPL(modify_ftrace_direct); + +static unsigned long hash_count(struct ftrace_hash *hash) +{ + return hash ? hash->count : 0; +} + +/** + * hash_add - adds two struct ftrace_hash and returns the result + * @a: struct ftrace_hash object + * @b: struct ftrace_hash object + * + * Returns struct ftrace_hash object on success, NULL on error. + */ +static struct ftrace_hash *hash_add(struct ftrace_hash *a, struct ftrace_hash *b) +{ + struct ftrace_func_entry *entry; + struct ftrace_hash *add; + int size; + + size = hash_count(a) + hash_count(b); + if (size > 32) + size = 32; + + add = alloc_and_copy_ftrace_hash(fls(size), a); + if (!add) + return NULL; + + size = 1 << b->size_bits; + for (int i = 0; i < size; i++) { + hlist_for_each_entry(entry, &b->buckets[i], hlist) { + if (add_ftrace_hash_entry_direct(add, entry->ip, entry->direct) == NULL) { + free_ftrace_hash(add); + return NULL; + } + } + } + return add; +} + +/** + * update_ftrace_direct_add - Updates @ops by adding direct + * callers provided in @hash + * @ops: The address of the struct ftrace_ops object + * @hash: The address of the struct ftrace_hash object + * + * This is used to add custom direct callers (ip -> addr) to @ops, + * specified in @hash. The @ops will be either registered or updated. + * + * Returns: zero on success. Non zero on error, which includes: + * -EINVAL - The @hash is empty + */ +int update_ftrace_direct_add(struct ftrace_ops *ops, struct ftrace_hash *hash) +{ + struct ftrace_hash *old_direct_functions = NULL; + struct ftrace_hash *new_direct_functions; + struct ftrace_hash *old_filter_hash; + struct ftrace_hash *new_filter_hash = NULL; + struct ftrace_func_entry *entry; + int err = -EINVAL; + int size; + bool reg; + + if (!hash_count(hash)) + return -EINVAL; + + mutex_lock(&direct_mutex); + + /* Make sure requested entries are not already registered. */ + size = 1 << hash->size_bits; + for (int i = 0; i < size; i++) { + hlist_for_each_entry(entry, &hash->buckets[i], hlist) { + if (__ftrace_lookup_ip(direct_functions, entry->ip)) + goto out_unlock; + } + } + + old_filter_hash = ops->func_hash ? ops->func_hash->filter_hash : NULL; + + /* If there's nothing in filter_hash we need to register the ops. */ + reg = hash_count(old_filter_hash) == 0; + if (reg) { + if (ops->func || ops->trampoline) + goto out_unlock; + if (ops->flags & FTRACE_OPS_FL_ENABLED) + goto out_unlock; + } + + err = -ENOMEM; + new_filter_hash = hash_add(old_filter_hash, hash); + if (!new_filter_hash) + goto out_unlock; + + new_direct_functions = hash_add(direct_functions, hash); + if (!new_direct_functions) + goto out_unlock; + + old_direct_functions = direct_functions; + rcu_assign_pointer(direct_functions, new_direct_functions); + + if (reg) { + ops->func = call_direct_funcs; + ops->flags |= MULTI_FLAGS; + ops->trampoline = FTRACE_REGS_ADDR; + ops->local_hash.filter_hash = new_filter_hash; + + err = register_ftrace_function_nolock(ops); + if (err) { + /* restore old filter on error */ + ops->local_hash.filter_hash = old_filter_hash; + + /* cleanup for possible another register call */ + ops->func = NULL; + ops->trampoline = 0; + } else { + new_filter_hash = old_filter_hash; + } + } else { + err = ftrace_update_ops(ops, new_filter_hash, EMPTY_HASH); + /* + * new_filter_hash is dup-ed, so we need to release it anyway, + * old_filter_hash either stays on error or is already released + */ + } + + if (err) { + /* reset direct_functions and free the new one */ + rcu_assign_pointer(direct_functions, old_direct_functions); + old_direct_functions = new_direct_functions; + } + + out_unlock: + mutex_unlock(&direct_mutex); + + if (old_direct_functions && old_direct_functions != EMPTY_HASH) + call_rcu_tasks(&old_direct_functions->rcu, register_ftrace_direct_cb); + free_ftrace_hash(new_filter_hash); + + return err; +} + +/** + * hash_sub - substracts @b from @a and returns the result + * @a: struct ftrace_hash object + * @b: struct ftrace_hash object + * + * Returns struct ftrace_hash object on success, NULL on error. + */ +static struct ftrace_hash *hash_sub(struct ftrace_hash *a, struct ftrace_hash *b) +{ + struct ftrace_func_entry *entry, *del; + struct ftrace_hash *sub; + int size; + + sub = alloc_and_copy_ftrace_hash(a->size_bits, a); + if (!sub) + return NULL; + + size = 1 << b->size_bits; + for (int i = 0; i < size; i++) { + hlist_for_each_entry(entry, &b->buckets[i], hlist) { + del = __ftrace_lookup_ip(sub, entry->ip); + if (WARN_ON_ONCE(!del)) { + free_ftrace_hash(sub); + return NULL; + } + remove_hash_entry(sub, del); + kfree(del); + } + } + return sub; +} + +/** + * update_ftrace_direct_del - Updates @ops by removing its direct + * callers provided in @hash + * @ops: The address of the struct ftrace_ops object + * @hash: The address of the struct ftrace_hash object + * + * This is used to delete custom direct callers (ip -> addr) in + * @ops specified via @hash. The @ops will be either unregistered + * updated. + * + * Returns: zero on success. Non zero on error, which includes: + * -EINVAL - The @hash is empty + * -EINVAL - The @ops is not registered + */ +int update_ftrace_direct_del(struct ftrace_ops *ops, struct ftrace_hash *hash) +{ + struct ftrace_hash *old_direct_functions = NULL; + struct ftrace_hash *new_direct_functions; + struct ftrace_hash *new_filter_hash = NULL; + struct ftrace_hash *old_filter_hash; + struct ftrace_func_entry *entry; + struct ftrace_func_entry *del; + unsigned long size; + int err = -EINVAL; + + if (!hash_count(hash)) + return -EINVAL; + if (check_direct_multi(ops)) + return -EINVAL; + if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) + return -EINVAL; + if (direct_functions == EMPTY_HASH) + return -EINVAL; + + mutex_lock(&direct_mutex); + + old_filter_hash = ops->func_hash ? ops->func_hash->filter_hash : NULL; + + if (!hash_count(old_filter_hash)) + goto out_unlock; + + /* Make sure requested entries are already registered. */ + size = 1 << hash->size_bits; + for (int i = 0; i < size; i++) { + hlist_for_each_entry(entry, &hash->buckets[i], hlist) { + del = __ftrace_lookup_ip(direct_functions, entry->ip); + if (!del || del->direct != entry->direct) + goto out_unlock; + } + } + + err = -ENOMEM; + new_filter_hash = hash_sub(old_filter_hash, hash); + if (!new_filter_hash) + goto out_unlock; + + new_direct_functions = hash_sub(direct_functions, hash); + if (!new_direct_functions) + goto out_unlock; + + /* If there's nothing left, we need to unregister the ops. */ + if (ftrace_hash_empty(new_filter_hash)) { + err = unregister_ftrace_function(ops); + if (!err) { + /* cleanup for possible another register call */ + ops->func = NULL; + ops->trampoline = 0; + ftrace_free_filter(ops); + ops->func_hash->filter_hash = NULL; + } + } else { + err = ftrace_update_ops(ops, new_filter_hash, EMPTY_HASH); + /* + * new_filter_hash is dup-ed, so we need to release it anyway, + * old_filter_hash either stays on error or is already released + */ + } + + if (err) { + /* free the new_direct_functions */ + old_direct_functions = new_direct_functions; + } else { + rcu_assign_pointer(direct_functions, new_direct_functions); + } + + out_unlock: + mutex_unlock(&direct_mutex); + + if (old_direct_functions && old_direct_functions != EMPTY_HASH) + call_rcu_tasks(&old_direct_functions->rcu, register_ftrace_direct_cb); + free_ftrace_hash(new_filter_hash); + + return err; +} + +/** + * update_ftrace_direct_mod - Updates @ops by modifing its direct + * callers provided in @hash + * @ops: The address of the struct ftrace_ops object + * @hash: The address of the struct ftrace_hash object + * @do_direct_lock: If true lock the direct_mutex + * + * This is used to modify custom direct callers (ip -> addr) in + * @ops specified via @hash. + * + * This can be called from within ftrace ops_func callback with + * direct_mutex already locked, in which case @do_direct_lock + * needs to be false. + * + * Returns: zero on success. Non zero on error, which includes: + * -EINVAL - The @hash is empty + * -EINVAL - The @ops is not registered + */ +int update_ftrace_direct_mod(struct ftrace_ops *ops, struct ftrace_hash *hash, bool do_direct_lock) +{ + struct ftrace_func_entry *entry, *tmp; + static struct ftrace_ops tmp_ops = { + .func = ftrace_stub, + .flags = FTRACE_OPS_FL_STUB, + }; + struct ftrace_hash *orig_hash; + unsigned long size, i; + int err = -EINVAL; + + if (!hash_count(hash)) + return -EINVAL; + if (check_direct_multi(ops)) + return -EINVAL; + if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) + return -EINVAL; + if (direct_functions == EMPTY_HASH) + return -EINVAL; + + /* + * We can be called from within ops_func callback with direct_mutex + * already taken. + */ + if (do_direct_lock) + mutex_lock(&direct_mutex); + + orig_hash = ops->func_hash ? ops->func_hash->filter_hash : NULL; + if (!orig_hash) + goto unlock; + + /* Enable the tmp_ops to have the same functions as the direct ops */ + ftrace_ops_init(&tmp_ops); + tmp_ops.func_hash = ops->func_hash; + + err = register_ftrace_function_nolock(&tmp_ops); + if (err) + goto unlock; + + /* + * Call __ftrace_hash_update_ipmodify() here, so that we can call + * ops->ops_func for the ops. This is needed because the above + * register_ftrace_function_nolock() worked on tmp_ops. + */ + err = __ftrace_hash_update_ipmodify(ops, orig_hash, orig_hash, true); + if (err) + goto out; + + /* + * Now the ftrace_ops_list_func() is called to do the direct callers. + * We can safely change the direct functions attached to each entry. + */ + mutex_lock(&ftrace_lock); + + size = 1 << hash->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry(entry, &hash->buckets[i], hlist) { + tmp = __ftrace_lookup_ip(direct_functions, entry->ip); + if (!tmp) + continue; + tmp->direct = entry->direct; + } + } + + mutex_unlock(&ftrace_lock); + +out: + /* Removing the tmp_ops will add the updated direct callers to the functions */ + unregister_ftrace_function(&tmp_ops); + +unlock: + if (do_direct_lock) + mutex_unlock(&direct_mutex); + return err; +} + #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ /** @@ -8708,7 +9066,7 @@ static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops) if (!op->ops_func) return -EBUSY; - ret = op->ops_func(op, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER); + ret = op->ops_func(op, ip, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER); if (ret) return ret; } @@ -8755,7 +9113,7 @@ static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops) /* The cleanup is optional, ignore any errors */ if (found_op && op->ops_func) - op->ops_func(op, FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER); + op->ops_func(op, ip, FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER); } } mutex_unlock(&direct_mutex); |