diff options
24 files changed, 1278 insertions, 692 deletions
diff --git a/Documentation/trace/user_events.rst b/Documentation/trace/user_events.rst index f9530d0ac5d3..d8f12442aaa6 100644 --- a/Documentation/trace/user_events.rst +++ b/Documentation/trace/user_events.rst @@ -14,6 +14,11 @@ Programs can view status of the events via /sys/kernel/tracing/user_events_status and can both register and write data out via /sys/kernel/tracing/user_events_data. +Programs can also use /sys/kernel/tracing/dynamic_events to register and +delete user based events via the u: prefix. The format of the command to +dynamic_events is the same as the ioctl with the u: prefix applied. This +requires CAP_PERFMON due to the event persisting, otherwise -EPERM is returned. + Typically programs will register a set of events that they wish to expose to tools that can read trace_events (such as ftrace and perf). The registration process tells the kernel which address and bit to reflect if any tool has @@ -45,7 +50,7 @@ This command takes a packed struct user_reg as an argument:: /* Input: Enable size in bytes at address */ __u8 enable_size; - /* Input: Flags for future use, set to 0 */ + /* Input: Flags to use, if any */ __u16 flags; /* Input: Address to update when enabled */ @@ -69,7 +74,7 @@ The struct user_reg requires all the above inputs to be set appropriately. This must be 4 (32-bit) or 8 (64-bit). 64-bit values are only allowed to be used on 64-bit kernels, however, 32-bit can be used on all kernels. -+ flags: The flags to use, if any. For the initial version this must be 0. ++ flags: The flags to use, if any. Callers should first attempt to use flags and retry without flags to ensure support for lower versions of the kernel. If a flag is not supported -EINVAL is returned. @@ -80,6 +85,13 @@ The struct user_reg requires all the above inputs to be set appropriately. + name_args: The name and arguments to describe the event, see command format for details. +The following flags are currently supported. + ++ USER_EVENT_REG_PERSIST: The event will not delete upon the last reference + closing. Callers may use this if an event should exist even after the + process closes or unregisters the event. Requires CAP_PERFMON otherwise + -EPERM is returned. + Upon successful registration the following is set. + write_index: The index to use for this file descriptor that represents this @@ -141,7 +153,10 @@ event (in both user and kernel space). User programs should use a separate file to request deletes than the one used for registration due to this. **NOTE:** By default events will auto-delete when there are no references left -to the event. Flags in the future may change this logic. +to the event. If programs do not want auto-delete, they must use the +USER_EVENT_REG_PERSIST flag when registering the event. Once that flag is used +the event exists until DIAG_IOCSDEL is invoked. Both register and delete of an +event that persists requires CAP_PERFMON, otherwise -EPERM is returned. Unregistering ------------- diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c index 20f72cd1d813..ca92cf0ffde1 100644 --- a/arch/powerpc/kernel/setup-common.c +++ b/arch/powerpc/kernel/setup-common.c @@ -601,7 +601,6 @@ struct seq_buf ppc_hw_desc __initdata = { .buffer = ppc_hw_desc_buf, .size = sizeof(ppc_hw_desc_buf), .len = 0, - .readpos = 0, }; static __init void probe_machine(void) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 8c8d64e76103..f8a594a50ae6 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -2,8 +2,9 @@ /* * event_inode.c - part of tracefs, a pseudo file system for activating tracing * - * Copyright (C) 2020-23 VMware Inc, author: Steven Rostedt (VMware) <rostedt@goodmis.org> + * Copyright (C) 2020-23 VMware Inc, author: Steven Rostedt <rostedt@goodmis.org> * Copyright (C) 2020-23 VMware Inc, author: Ajay Kaher <akaher@vmware.com> + * Copyright (C) 2023 Google, author: Steven Rostedt <rostedt@goodmis.org> * * eventfs is used to dynamically create inodes and dentries based on the * meta data provided by the tracing system. @@ -23,48 +24,30 @@ #include <linux/delay.h> #include "internal.h" -struct eventfs_inode { - struct list_head e_top_files; -}; +/* + * eventfs_mutex protects the eventfs_inode (ei) dentry. Any access + * to the ei->dentry must be done under this mutex and after checking + * if ei->is_freed is not set. The ei->dentry is released under the + * mutex at the same time ei->is_freed is set. If ei->is_freed is set + * then the ei->dentry is invalid. + */ +static DEFINE_MUTEX(eventfs_mutex); /* - * struct eventfs_file - hold the properties of the eventfs files and - * directories. - * @name: the name of the file or directory to create - * @d_parent: holds parent's dentry - * @dentry: once accessed holds dentry - * @list: file or directory to be added to parent directory - * @ei: list of files and directories within directory - * @fop: file_operations for file or directory - * @iop: inode_operations for file or directory - * @data: something that the caller will want to get to later on - * @mode: the permission that the file or directory should have + * The eventfs_inode (ei) itself is protected by SRCU. It is released from + * its parent's list and will have is_freed set (under eventfs_mutex). + * After the SRCU grace period is over, the ei may be freed. */ -struct eventfs_file { - const char *name; - struct dentry *d_parent; - struct dentry *dentry; - struct list_head list; - struct eventfs_inode *ei; - const struct file_operations *fop; - const struct inode_operations *iop; - /* - * Union - used for deletion - * @del_list: list of eventfs_file to delete - * @rcu: eventfs_file to delete in RCU - * @is_freed: node is freed if one of the above is set - */ - union { - struct list_head del_list; - struct rcu_head rcu; - unsigned long is_freed; - }; - void *data; - umode_t mode; +DEFINE_STATIC_SRCU(eventfs_srcu); + +/* Mode is unsigned short, use the upper bits for flags */ +enum { + EVENTFS_SAVE_MODE = BIT(16), + EVENTFS_SAVE_UID = BIT(17), + EVENTFS_SAVE_GID = BIT(18), }; -static DEFINE_MUTEX(eventfs_mutex); -DEFINE_STATIC_SRCU(eventfs_srcu); +#define EVENTFS_MODE_MASK (EVENTFS_SAVE_MODE - 1) static struct dentry *eventfs_root_lookup(struct inode *dir, struct dentry *dentry, @@ -73,8 +56,88 @@ static int dcache_dir_open_wrapper(struct inode *inode, struct file *file); static int dcache_readdir_wrapper(struct file *file, struct dir_context *ctx); static int eventfs_release(struct inode *inode, struct file *file); +static void update_attr(struct eventfs_attr *attr, struct iattr *iattr) +{ + unsigned int ia_valid = iattr->ia_valid; + + if (ia_valid & ATTR_MODE) { + attr->mode = (attr->mode & ~EVENTFS_MODE_MASK) | + (iattr->ia_mode & EVENTFS_MODE_MASK) | + EVENTFS_SAVE_MODE; + } + if (ia_valid & ATTR_UID) { + attr->mode |= EVENTFS_SAVE_UID; + attr->uid = iattr->ia_uid; + } + if (ia_valid & ATTR_GID) { + attr->mode |= EVENTFS_SAVE_GID; + attr->gid = iattr->ia_gid; + } +} + +static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry, + struct iattr *iattr) +{ + const struct eventfs_entry *entry; + struct eventfs_inode *ei; + const char *name; + int ret; + + mutex_lock(&eventfs_mutex); + ei = dentry->d_fsdata; + if (ei->is_freed) { + /* Do not allow changes if the event is about to be removed. */ + mutex_unlock(&eventfs_mutex); + return -ENODEV; + } + + /* Preallocate the children mode array if necessary */ + if (!(dentry->d_inode->i_mode & S_IFDIR)) { + if (!ei->entry_attrs) { + ei->entry_attrs = kzalloc(sizeof(*ei->entry_attrs) * ei->nr_entries, + GFP_KERNEL); + if (!ei->entry_attrs) { + ret = -ENOMEM; + goto out; + } + } + } + + ret = simple_setattr(idmap, dentry, iattr); + if (ret < 0) + goto out; + + /* + * If this is a dir, then update the ei cache, only the file + * mode is saved in the ei->m_children, and the ownership is + * determined by the parent directory. + */ + if (dentry->d_inode->i_mode & S_IFDIR) { + update_attr(&ei->attr, iattr); + + } else { + name = dentry->d_name.name; + + for (int i = 0; i < ei->nr_entries; i++) { + entry = &ei->entries[i]; + if (strcmp(name, entry->name) == 0) { + update_attr(&ei->entry_attrs[i], iattr); + break; + } + } + } + out: + mutex_unlock(&eventfs_mutex); + return ret; +} + static const struct inode_operations eventfs_root_dir_inode_operations = { .lookup = eventfs_root_lookup, + .setattr = eventfs_set_attr, +}; + +static const struct inode_operations eventfs_file_inode_operations = { + .setattr = eventfs_set_attr, }; static const struct file_operations eventfs_file_operations = { @@ -85,26 +148,40 @@ static const struct file_operations eventfs_file_operations = { .release = eventfs_release, }; +static void update_inode_attr(struct inode *inode, struct eventfs_attr *attr, umode_t mode) +{ + if (!attr) { + inode->i_mode = mode; + return; + } + + if (attr->mode & EVENTFS_SAVE_MODE) + inode->i_mode = attr->mode & EVENTFS_MODE_MASK; + else + inode->i_mode = mode; + + if (attr->mode & EVENTFS_SAVE_UID) + inode->i_uid = attr->uid; + + if (attr->mode & EVENTFS_SAVE_GID) + inode->i_gid = attr->gid; +} + /** * create_file - create a file in the tracefs filesystem * @name: the name of the file to create. * @mode: the permission that the file should have. + * @attr: saved attributes changed by user * @parent: parent dentry for this file. * @data: something that the caller will want to get to later on. * @fop: struct file_operations that should be used for this file. * - * This is the basic "create a file" function for tracefs. It allows for a - * wide range of flexibility in creating a file. - * - * This function will return a pointer to a dentry if it succeeds. This - * pointer must be passed to the tracefs_remove() function when the file is - * to be removed (no automatic cleanup happens if your module is unloaded, - * you are responsible here.) If an error occurs, %NULL will be returned. - * - * If tracefs is not enabled in the kernel, the value -%ENODEV will be - * returned. + * This function creates a dentry that represents a file in the eventsfs_inode + * directory. The inode.i_private pointer will point to @data in the open() + * call. */ static struct dentry *create_file(const char *name, umode_t mode, + struct eventfs_attr *attr, struct dentry *parent, void *data, const struct file_operations *fop) { @@ -118,6 +195,7 @@ static struct dentry *create_file(const char *name, umode_t mode, if (WARN_ON_ONCE(!S_ISREG(mode))) return NULL; + WARN_ON_ONCE(!parent); dentry = eventfs_start_creating(name, parent); if (IS_ERR(dentry)) @@ -127,7 +205,10 @@ static struct dentry *create_file(const char *name, umode_t mode, if (unlikely(!inode)) return eventfs_failed_creating(dentry); - inode->i_mode = mode; + /* If the user updated the directory's attributes, use them */ + update_inode_attr(inode, attr, mode); + + inode->i_op = &eventfs_file_inode_operations; inode->i_fop = fop; inode->i_private = data; @@ -140,28 +221,19 @@ static struct dentry *create_file(const char *name, umode_t mode, /** * create_dir - create a dir in the tracefs filesystem - * @name: the name of the file to create. + * @ei: the eventfs_inode that represents the directory to create * @parent: parent dentry for this file. - * @data: something that the caller will want to get to later on. * - * This is the basic "create a dir" function for eventfs. It allows for a - * wide range of flexibility in creating a dir. - * - * This function will return a pointer to a dentry if it succeeds. This - * pointer must be passed to the tracefs_remove() function when the file is - * to be removed (no automatic cleanup happens if your module is unloaded, - * you are responsible here.) If an error occurs, %NULL will be returned. - * - * If tracefs is not enabled in the kernel, the value -%ENODEV will be - * returned. + * This function will create a dentry for a directory represented by + * a eventfs_inode. */ -static struct dentry *create_dir(const char *name, struct dentry *parent, void *data) +static struct dentry *create_dir(struct eventfs_inode *ei, struct dentry *parent) { struct tracefs_inode *ti; struct dentry *dentry; struct inode *inode; - dentry = eventfs_start_creating(name, parent); + dentry = eventfs_start_creating(ei->name, parent); if (IS_ERR(dentry)) return dentry; @@ -169,10 +241,11 @@ static struct dentry *create_dir(const char *name, struct dentry *parent, void * if (unlikely(!inode)) return eventfs_failed_creating(dentry); - inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO; + /* If the user updated the directory's attributes, use them */ + update_inode_attr(inode, &ei->attr, S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO); + inode->i_op = &eventfs_root_dir_inode_operations; inode->i_fop = &eventfs_file_operations; - inode->i_private = data; ti = get_tracefs(inode); ti->flags |= TRACEFS_EVENT_INODE; @@ -184,117 +257,198 @@ static struct dentry *create_dir(const char *name, struct dentry *parent, void * return eventfs_end_creating(dentry); } +static void free_ei(struct eventfs_inode *ei) +{ + kfree_const(ei->name); + kfree(ei->d_children); + kfree(ei->entry_attrs); + kfree(ei); +} + /** - * eventfs_set_ef_status_free - set the ef->status to free + * eventfs_set_ei_status_free - remove the dentry reference from an eventfs_inode * @ti: the tracefs_inode of the dentry - * @dentry: dentry who's status to be freed + * @dentry: dentry which has the reference to remove. * - * eventfs_set_ef_status_free will be called if no more - * references remain + * Remove the association between a dentry from an eventfs_inode. */ -void eventfs_set_ef_status_free(struct tracefs_inode *ti, struct dentry *dentry) +void eventfs_set_ei_status_free(struct tracefs_inode *ti, struct dentry *dentry) { - struct tracefs_inode *ti_parent; struct eventfs_inode *ei; - struct eventfs_file *ef, *tmp; - - /* The top level events directory may be freed by this */ - if (unlikely(ti->flags & TRACEFS_EVENT_TOP_INODE)) { - LIST_HEAD(ef_del_list); + int i; - mutex_lock(&eventfs_mutex); + mutex_lock(&eventfs_mutex); - ei = ti->private; + ei = dentry->d_fsdata; + if (!ei) + goto out; - /* Record all the top level files */ - list_for_each_entry_srcu(ef, &ei->e_top_files, list, - lockdep_is_held(&eventfs_mutex)) { - list_add_tail(&ef->del_list, &ef_del_list); + /* This could belong to one of the files of the ei */ + if (ei->dentry != dentry) { + for (i = 0; i < ei->nr_entries; i++) { + if (ei->d_children[i] == dentry) + break; } + if (WARN_ON_ONCE(i == ei->nr_entries)) + goto out; + ei->d_children[i] = NULL; + } else if (ei->is_freed) { + free_ei(ei); + } else { + ei->dentry = NULL; + } + + dentry->d_fsdata = NULL; + out: + mutex_unlock(&eventfs_mutex); +} - /* Nothing should access this, but just in case! */ - ti->private = NULL; +/** + * create_file_dentry - create a dentry for a file of an eventfs_inode + * @ei: the eventfs_inode that the file will be created under + * @idx: the index into the d_children[] of the @ei + * @parent: The parent dentry of the created file. + * @name: The name of the file to create + * @mode: The mode of the file. + * @data: The data to use to set the inode of the file with on open() + * @fops: The fops of the file to be created. + * @lookup: If called by the lookup routine, in which case, dput() the created dentry. + * + * Create a dentry for a file of an eventfs_inode @ei and place it into the + * address located at @e_dentry. If the @e_dentry already has a dentry, then + * just do a dget() on it and return. Otherwise create the dentry and attach it. + */ +static struct dentry * +create_file_dentry(struct eventfs_inode *ei, int idx, + struct dentry *parent, const char *name, umode_t mode, void *data, + const struct file_operations *fops, bool lookup) +{ + struct eventfs_attr *attr = NULL; + struct dentry **e_dentry = &ei->d_children[idx]; + struct dentry *dentry; + bool invalidate = false; + mutex_lock(&eventfs_mutex); + if (ei->is_freed) { mutex_unlock(&eventfs_mutex); + return NULL; + } + /* If the e_dentry already has a dentry, use it */ + if (*e_dentry) { + /* lookup does not need to up the ref count */ + if (!lookup) + dget(*e_dentry); + mutex_unlock(&eventfs_mutex); + return *e_dentry; + } - /* Now safely free the top level files and their children */ - list_for_each_entry_safe(ef, tmp, &ef_del_list, del_list) { - list_del(&ef->del_list); - eventfs_remove(ef); - } + /* ei->entry_attrs are protected by SRCU */ + if (ei->entry_attrs) + attr = &ei->entry_attrs[idx]; - kfree(ei); - return; - } + mutex_unlock(&eventfs_mutex); - mutex_lock(&eventfs_mutex); + /* The lookup already has the parent->d_inode locked */ + if (!lookup) + inode_lock(parent->d_inode); - ti_parent = get_tracefs(dentry->d_parent->d_inode); - if (!ti_parent || !(ti_parent->flags & TRACEFS_EVENT_INODE)) - goto out; + dentry = create_file(name, mode, attr, parent, data, fops); - ef = dentry->d_fsdata; - if (!ef) - goto out; + if (!lookup) + inode_unlock(parent->d_inode); - /* - * If ef was freed, then the LSB bit is set for d_fsdata. - * But this should not happen, as it should still have a - * ref count that prevents it. Warn in case it does. - */ - if (WARN_ON_ONCE((unsigned long)ef & 1)) - goto out; + mutex_lock(&eventfs_mutex); - dentry->d_fsdata = NULL; - ef->dentry = NULL; -out: + if (IS_ERR_OR_NULL(dentry)) { + /* + * When the mutex was released, something else could have + * created the dentry for this e_dentry. In which case + * use that one. + * + * Note, with the mutex held, the e_dentry cannot have content + * and the ei->is_freed be true at the same time. + */ + dentry = *e_dentry; + if (WARN_ON_ONCE(dentry && ei->is_freed)) + dentry = NULL; + /* The lookup does not need to up the dentry refcount */ + if (dentry && !lookup) + dget(dentry); + mutex_unlock(&eventfs_mutex); + return dentry; + } + + if (!*e_dentry && !ei->is_freed) { + *e_dentry = dentry; + dentry->d_fsdata = ei; + } else { + /* + * Should never happen unless we get here due to being freed. + * Otherwise it means two dentries exist with the same name. + */ + WARN_ON_ONCE(!ei->is_freed); + invalidate = true; + } mutex_unlock(&eventfs_mutex); + + if (invalidate) + d_invalidate(dentry); + + if (lookup || invalidate) + dput(dentry); + + return invalidate ? NULL : dentry; } /** * eventfs_post_create_dir - post create dir routine - * @ef: eventfs_file of recently created dir + * @ei: eventfs_inode of recently created dir * * Map the meta-data of files within an eventfs dir to their parent dentry */ -static void eventfs_post_create_dir(struct eventfs_file *ef) +static void eventfs_post_create_dir(struct eventfs_inode *ei) { - struct eventfs_file *ef_child; + struct eventfs_inode *ei_child; struct tracefs_inode *ti; + lockdep_assert_held(&eventfs_mutex); + /* srcu lock already held */ /* fill parent-child relation */ - list_for_each_entry_srcu(ef_child, &ef->ei->e_top_files, list, + list_for_each_entry_srcu(ei_child, &ei->children, list, srcu_read_lock_held(&eventfs_srcu)) { - ef_child->d_parent = ef->dentry; + ei_child->d_parent = ei->dentry; } - ti = get_tracefs(ef->dentry->d_inode); - ti->private = ef->ei; + ti = get_tracefs(ei->dentry->d_inode); + ti->private = ei; } /** - * create_dentry - helper function to create dentry - * @ef: eventfs_file of file or directory to create - * @parent: parent dentry - * @lookup: true if called from lookup routine + * create_dir_dentry - Create a directory dentry for the eventfs_inode + * @pei: The eventfs_inode parent of ei. + * @ei: The eventfs_inode to create the directory for + * @parent: The dentry of the parent of this directory + * @lookup: True if this is called by the lookup code * - * Used to create a dentry for file/dir, executes post dentry creation routine + * This creates and attaches a directory dentry to the eventfs_inode @ei. */ static struct dentry * -create_dentry(struct eventfs_file *ef, struct dentry *parent, bool lookup) +create_dir_dentry(struct eventfs_inode *pei, struct eventfs_inode *ei, + struct dentry *parent, bool lookup) { bool invalidate = false; - struct dentry *dentry; + struct dentry *dentry = NULL; mutex_lock(&eventfs_mutex); - if (ef->is_freed) { + if (pei->is_freed || ei->is_freed) { mutex_unlock(&eventfs_mutex); return NULL; } - if (ef->dentry) { - dentry = ef->dentry; - /* On dir open, up the ref count */ + if (ei->dentry) { + /* If the dentry already has a dentry, use it */ + dentry = ei->dentry; + /* lookup does not need to up the ref count */ if (!lookup) dget(dentry); mutex_unlock(&eventfs_mutex); @@ -302,42 +456,44 @@ create_dentry(struct eventfs_file *ef, struct dentry *parent, bool lookup) } mutex_unlock(&eventfs_mutex); + /* The lookup already has the parent->d_inode locked */ if (!lookup) inode_lock(parent->d_inode); - if (ef->ei) - dentry = create_dir(ef->name, parent, ef->data); - else - dentry = create_file(ef->name, ef->mode, parent, - ef->data, ef->fop); + dentry = create_dir(ei, parent); if (!lookup) inode_unlock(parent->d_inode); mutex_lock(&eventfs_mutex); - if (IS_ERR_OR_NULL(dentry)) { - /* If the ef was already updated get it */ - dentry = ef->dentry; + + if (IS_ERR_OR_NULL(dentry) && !ei->is_freed) { + /* + * When the mutex was released, something else could have + * created the dentry for this e_dentry. In which case + * use that one. + * + * Note, with the mutex held, the e_dentry cannot have content + * and the ei->is_freed be true at the same time. + */ + dentry = ei->dentry; if (dentry && !lookup) dget(dentry); mutex_unlock(&eventfs_mutex); return dentry; } - if (!ef->dentry && !ef->is_freed) { - ef->dentry = dentry; - if (ef->ei) - eventfs_post_create_dir(ef); - dentry->d_fsdata = ef; + if (!ei->dentry && !ei->is_freed) { + ei->dentry = dentry; + eventfs_post_create_dir(ei); + dentry->d_fsdata = ei; } else { - /* A race here, should try again (unless freed) */ - invalidate = true; - /* * Should never happen unless we get here due to being freed. * Otherwise it means two dentries exist with the same name. */ - WARN_ON_ONCE(!ef->is_freed); + WARN_ON_ONCE(!ei->is_freed); + invalidate = true; } mutex_unlock(&eventfs_mutex); if (invalidate) @@ -349,50 +505,90 @@ create_dentry(struct eventfs_file *ef, struct dentry *parent, bool lookup) return invalidate ? NULL : dentry; } -static bool match_event_file(struct eventfs_file *ef, const char *name) -{ - bool ret; - - mutex_lock(&eventfs_mutex); - ret = !ef->is_freed && strcmp(ef->name, name) == 0; - mutex_unlock(&eventfs_mutex); - - return ret; -} - /** * eventfs_root_lookup - lookup routine to create file/dir * @dir: in which a lookup is being done * @dentry: file/dir dentry - * @flags: to pass as flags parameter to simple lookup + * @flags: Just passed to simple_lookup() * - * Used to create a dynamic file/dir within @dir. Use the eventfs_inode - * list of meta data to find the information needed to create the file/dir. + * Used to create dynamic file/dir with-in @dir, search with-in @ei + * list, if @dentry found go ahead and create the file/dir */ + static struct dentry *eventfs_root_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { + const struct file_operations *fops; + const struct eventfs_entry *entry; + struct eventfs_inode *ei_child; struct tracefs_inode *ti; struct eventfs_inode *ei; - struct eventfs_file *ef; + struct dentry *ei_dentry = NULL; struct dentry *ret = NULL; + const char *name = dentry->d_name.name; + bool created = false; + umode_t mode; + void *data; int idx; + int i; + int r; ti = get_tracefs(dir); if (!(ti->flags & TRACEFS_EVENT_INODE)) return NULL; - ei = ti->private; + /* Grab srcu to prevent the ei from going away */ idx = srcu_read_lock(&eventfs_srcu); - list_for_each_entry_srcu(ef, &ei->e_top_files, list, + + /* + * Grab the eventfs_mutex to consistent value from ti->private. + * This s + */ + mutex_lock(&eventfs_mutex); + ei = READ_ONCE(ti->private); + if (ei && !ei->is_freed) + ei_dentry = READ_ONCE(ei->dentry); + mutex_unlock(&eventfs_mutex); + + if (!ei || !ei_dentry) + goto out; + + data = ei->data; + + list_for_each_entry_srcu(ei_child, &ei->children, list, srcu_read_lock_held(&eventfs_srcu)) { - if (!match_event_file(ef, dentry->d_name.name)) + if (strcmp(ei_child->name, name) != 0) continue; ret = simple_lookup(dir, dentry, flags); - create_dentry(ef, ef->d_parent, true); + create_dir_dentry(ei, ei_child, ei_dentry, true); + created = true; break; } + + if (created) + goto out; + + for (i = 0; i < ei->nr_entries; i++) { + entry = &ei->entries[i]; + if (strcmp(name, entry->name) == 0) { + void *cdata = data; + mutex_lock(&eventfs_mutex); + /* If ei->is_freed, then the event itself may be too */ + if (!ei->is_freed) + r = entry->callback(name, &mode, &cdata, &fops); + else + r = -1; + mutex_unlock(&eventfs_mutex); + if (r <= 0) + continue; + ret = simple_lookup(dir, dentry, flags); + create_file_dentry(ei, i, ei_dentry, name, mode, cdata, + fops, true); + break; + } + } + out: srcu_read_unlock(&eventfs_srcu, idx); return ret; } @@ -432,29 +628,48 @@ static int eventfs_release(struct inode *inode, struct file *file) return dcache_dir_close(inode, file); } +static int add_dentries(struct dentry ***dentries, struct dentry *d, int cnt) +{ + struct dentry **tmp; + + tmp = krealloc(*dentries, sizeof(d) * (cnt + 2), GFP_KERNEL); + if (!tmp) + return -1; + tmp[cnt] = d; + tmp[cnt + 1] = NULL; + *dentries = tmp; + return 0; +} + /** * dcache_dir_open_wrapper - eventfs open wrapper * @inode: not used - * @file: dir to be opened (to create its child) + * @file: dir to be opened (to create it's children) * - * Used to dynamically create the file/dir within @file. @file is really a - * directory and all the files/dirs of the children within @file will be - * created. If any of the files/dirs have already been created, their - * reference count will be incremented. + * Used to dynamic create file/dir with-in @file, all the + * file/dir will be created. If already created then references + * will be increased */ static int dcache_dir_open_wrapper(struct inode *inode, struct file *file) { + const struct file_operations *fops; + const struct eventfs_entry *entry; + struct eventfs_inode *ei_child; struct tracefs_inode *ti; struct eventfs_inode *ei; - struct eventfs_file *ef; struct dentry_list *dlist; struct dentry **dentries = NULL; - struct dentry *dentry = file_dentry(file); + struct dentry *parent = file_dentry(file); struct dentry *d; struct inode *f_inode = file_inode(file); + const char *name = parent->d_name.name; + umode_t mode; + void *data; int cnt = 0; int idx; int ret; + int i; + int r; ti = get_tracefs(f_inode); if (!(ti->flags & TRACEFS_EVENT_INODE)) @@ -463,25 +678,56 @@ static int dcache_dir_open_wrapper(struct inode *inode, struct file *file) if (WARN_ON_ONCE(file->private_data)) return -EINVAL; + idx = srcu_read_lock(&eventfs_srcu); + + mutex_lock(&eventfs_mutex); + ei = READ_ONCE(ti->private); + mutex_unlock(&eventfs_mutex); + + if (!ei) { + srcu_read_unlock(&eventfs_srcu, idx); + return -EINVAL; + } + + + data = ei->data; + dlist = kmalloc(sizeof(*dlist), GFP_KERNEL); - if (!dlist) + if (!dlist) { + srcu_read_unlock(&eventfs_srcu, idx); return -ENOMEM; + } - ei = ti->private; - idx = srcu_read_lock(&eventfs_srcu); - list_for_each_entry_srcu(ef, &ei->e_top_files, list, + list_for_each_entry_srcu(ei_child, &ei->children, list, srcu_read_lock_held(&eventfs_srcu)) { - d = create_dentry(ef, dentry, false); + d = create_dir_dentry(ei, ei_child, parent, false); if (d) { - struct dentry **tmp; + ret = add_dentries(&dentries, d, cnt); + if (ret < 0) + break; + cnt++; + } + } - tmp = krealloc(dentries, sizeof(d) * (cnt + 2), GFP_KERNEL); - if (!tmp) + for (i = 0; i < ei->nr_entries; i++) { + void *cdata = data; + entry = &ei->entries[i]; + name = entry->name; + mutex_lock(&eventfs_mutex); + /* If ei->is_freed, then the event itself may be too */ + if (!ei->is_freed) + r = entry->callback(name, &mode, &cdata, &fops); + else + r = -1; + mutex_unlock(&eventfs_mutex); + if (r <= 0) + continue; + d = create_file_dentry(ei, i, parent, name, mode, cdata, fops, false); + if (d) { + ret = add_dentries(&dentries, d, cnt); + if (ret < 0) break; - tmp[cnt] = d; - tmp[cnt + 1] = NULL; cnt++; - dentries = tmp; } } srcu_read_unlock(&eventfs_srcu, idx); @@ -514,63 +760,104 @@ static int dcache_readdir_wrapper(struct file *file, struct dir_context *ctx) } /** - * eventfs_prepare_ef - helper function to prepare eventfs_file - * @name: the name of the file/directory to create. - * @mode: the permission that the file should have. - * @fop: struct file_operations that should be used for this file/directory. - * @iop: struct inode_operations that should be used for this file/directory. - * @data: something that the caller will want to get to later on. The - * inode.i_private pointer will point to this value on the open() call. + * eventfs_create_dir - Create the eventfs_inode for this directory + * @name: The name of the directory to create. + * @parent: The eventfs_inode of the parent directory. + * @entries: A list of entries that represent the files under this directory + * @size: The number of @entries + * @data: The default data to pass to the files (an entry may override it). + * + * This function creates the descriptor to represent a directory in the + * eventfs. This descriptor is an eventfs_inode, and it is returned to be + * used to create other children underneath. + * + * The @entries is an array of eventfs_entry structures which has: + * const char *name + * eventfs_callback callback; * - * This function allocates and fills the eventfs_file structure. + * The name is the name of the file, and the callback is a pointer to a function + * that will be called when the file is reference (either by lookup or by + * reading a directory). The callback is of the prototype: + * + * int callback(const char *name, umode_t *mode, void **data, + * const struct file_operations **fops); + * + * When a file needs to be created, this callback will be called with + * name = the name of the file being created (so that the same callback + * may be used for multiple files). + * mode = a place to set the file's mode + * data = A pointer to @data, and the callback may replace it, which will + * cause the file created to pass the new data to the open() call. + * fops = the fops to use for the created file. + * + * NB. @callback is called while holding internal locks of the eventfs + * system. The callback must not call any code that might also call into + * the tracefs or eventfs system or it will risk creating a deadlock. */ -static struct eventfs_file *eventfs_prepare_ef(const char *name, umode_t mode, - const struct file_operations *fop, - const struct inode_operations *iop, - void *data) +struct eventfs_inode *eventfs_create_dir(const char *name, struct eventfs_inode *parent, + const struct eventfs_entry *entries, + int size, void *data) { - struct eventfs_file *ef; + struct eventfs_inode *ei; - ef = kzalloc(sizeof(*ef), GFP_KERNEL); - if (!ef) + if (!parent) + return ERR_PTR(-EINVAL); + + ei = kzalloc(sizeof(*ei), GFP_KERNEL); + if (!ei) return ERR_PTR(-ENOMEM); - ef->name = kstrdup(name, GFP_KERNEL); - if (!ef->name) { - kfree(ef); + ei->name = kstrdup_const(name, GFP_KERNEL); + if (!ei->name) { + kfree(ei); return ERR_PTR(-ENOMEM); } - if (S_ISDIR(mode)) { - ef->ei = kzalloc(sizeof(*ef->ei), GFP_KERNEL); - if (!ef->ei) { - kfree(ef->name); - kfree(ef); + if (size) { + ei->d_children = kzalloc(sizeof(*ei->d_children) * size, GFP_KERNEL); + if (!ei->d_children) { + kfree_const(ei->name); + kfree(ei); return ERR_PTR(-ENOMEM); } - INIT_LIST_HEAD(&ef->ei->e_top_files); - } else { - ef->ei = NULL; } - ef->iop = iop; - ef->fop = fop; - ef->mode = mode; - ef->data = data; - return ef; + ei->entries = entries; + ei->nr_entries = size; + ei->data = data; + INIT_LIST_HEAD(&ei->children); + INIT_LIST_HEAD(&ei->list); + + mutex_lock(&eventfs_mutex); + if (!parent->is_freed) { + list_add_tail(&ei->list, &parent->children); + ei->d_parent = parent->dentry; + } + mutex_unlock(&eventfs_mutex); + + /* Was the parent freed? */ + if (list_empty(&ei->list)) { + free_ei(ei); + ei = NULL; + } + return ei; } /** - * eventfs_create_events_dir - create the trace event structure - * @name: the name of the directory to create. - * @parent: parent dentry for this file. This should be a directory dentry - * if set. If this parameter is NULL, then the directory will be - * created in the root of the tracefs filesystem. + * eventfs_create_events_dir - create the top level events directory + * @name: The name of the top level directory to create. + * @parent: Parent dentry for this file in the tracefs directory. + * @entries: A list of entries that represent the files under this directory + * @size: The number of @entries + * @data: The default data to pass to the files (an entry may override it). * * This function creates the top of the trace event directory. + * + * See eventfs_create_dir() for use of @entries. */ -struct dentry *eventfs_create_events_dir(const char *name, - struct dentry *parent) +struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry *parent, + const struct eventfs_entry *entries, + int size, void *data) { struct dentry *dentry = tracefs_start_creating(name, parent); struct eventfs_inode *ei; @@ -581,19 +868,32 @@ struct dentry *eventfs_create_events_dir(const char *name, return NULL; if (IS_ERR(dentry)) - return dentry; + return ERR_CAST(dentry); ei = kzalloc(sizeof(*ei), GFP_KERNEL); if (!ei) - return ERR_PTR(-ENOMEM); + goto fail_ei; + inode = tracefs_get_inode(dentry->d_sb); - if (unlikely(!inode)) { - kfree(ei); - tracefs_failed_creating(dentry); - return ERR_PTR(-ENOMEM); + if (unlikely(!inode)) + goto fail; + + if (size) { + ei->d_children = kzalloc(sizeof(*ei->d_children) * size, GFP_KERNEL); + if (!ei->d_children) + goto fail; } - INIT_LIST_HEAD(&ei->e_top_files); + ei->dentry = dentry; + ei->entries = entries; + ei->nr_entries = size; + ei->data = data; + ei->name = kstrdup_const(name, GFP_KERNEL); + if (!ei->name) + goto fail; + + INIT_LIST_HEAD(&ei->children); + INIT_LIST_HEAD(&ei->list); ti = get_tracefs(inode); ti->flags |= TRACEFS_EVENT_INODE | TRACEFS_EVENT_TOP_INODE; @@ -603,198 +903,97 @@ struct dentry *eventfs_create_events_dir(const char *name, inode->i_op = &eventfs_root_dir_inode_operations; inode->i_fop = &eventfs_file_operations; + dentry->d_fsdata = ei; + /* directory inodes start off with i_nlink == 2 (for "." entry) */ inc_nlink(inode); d_instantiate(dentry, inode); inc_nlink(dentry->d_parent->d_inode); fsnotify_mkdir(dentry->d_parent->d_inode, dentry); - return tracefs_end_creating(dentry); -} - -/** - * eventfs_add_subsystem_dir - add eventfs subsystem_dir to list to create later - * @name: the name of the file to create. - * @parent: parent dentry for this dir. - * - * This function adds eventfs subsystem dir to list. - * And all these dirs are created on the fly when they are looked up, - * and the dentry and inodes will be removed when they are done. - */ -struct eventfs_file *eventfs_add_subsystem_dir(const char *name, - struct dentry *parent) -{ - struct tracefs_inode *ti_parent; - struct eventfs_inode *ei_parent; - struct eventfs_file *ef; - - if (security_locked_down(LOCKDOWN_TRACEFS)) - return NULL; - - if (!parent) - return ERR_PTR(-EINVAL); - - ti_parent = get_tracefs(parent->d_inode); - ei_parent = ti_parent->private; + tracefs_end_creating(dentry); - ef = eventfs_prepare_ef(name, S_IFDIR, NULL, NULL, NULL); - if (IS_ERR(ef)) - return ef; + return ei; - mutex_lock(&eventfs_mutex); - list_add_tail(&ef->list, &ei_parent->e_top_files); - ef->d_parent = parent; - mutex_unlock(&eventfs_mutex); - return ef; + fail: + kfree(ei->d_children); + kfree(ei); + fail_ei: + tracefs_failed_creating(dentry); + return ERR_PTR(-ENOMEM); } -/** - * eventfs_add_dir - add eventfs dir to list to create later - * @name: the name of the file to create. - * @ef_parent: parent eventfs_file for this dir. - * - * This function adds eventfs dir to list. - * And all these dirs are created on the fly when they are looked up, - * and the dentry and inodes will be removed when they are done. - */ -struct eventfs_file *eventfs_add_dir(const char *name, - struct eventfs_file *ef_parent) -{ - struct eventfs_file *ef; - - if (security_locked_down(LOCKDOWN_TRACEFS)) - return NULL; - - if (!ef_parent) - return ERR_PTR(-EINVAL); - - ef = eventfs_prepare_ef(name, S_IFDIR, NULL, NULL, NULL); - if (IS_ERR(ef)) - return ef; +static LLIST_HEAD(free_list); - mutex_lock(&eventfs_mutex); - list_add_tail(&ef->list, &ef_parent->ei->e_top_files); - ef->d_parent = ef_parent->dentry; - mutex_unlock(&eventfs_mutex); - return ef; -} - -/** - * eventfs_add_events_file - add the data needed to create a file for later reference - * @name: the name of the file to create. - * @mode: the permission that the file should have. - * @parent: parent dentry for this file. - * @data: something that the caller will want to get to later on. - * @fop: struct file_operations that should be used for this file. - * - * This function is used to add the information needed to create a - * dentry/inode within the top level events directory. The file created - * will have the @mode permissions. The @data will be used to fill the - * inode.i_private when the open() call is done. The dentry and inodes are - * all created when they are referenced, and removed when they are no - * longer referenced. - */ -int eventfs_add_events_file(const char *name, umode_t mode, - struct dentry *parent, void *data, - const struct file_operations *fop) +static void eventfs_workfn(struct work_struct *work) { - struct tracefs_inode *ti; - struct eventfs_inode *ei; - struct eventfs_file *ef; - - if (security_locked_down(LOCKDOWN_TRACEFS)) - return -ENODEV; - - if (!parent) - return -EINVAL; - - if (!(mode & S_IFMT)) - mode |= S_IFREG; - - if (!parent->d_inode) - return -EINVAL; - - ti = get_tracefs(parent->d_inode); - if (!(ti->flags & TRACEFS_EVENT_INODE)) - return -EINVAL; - - ei = ti->private; - ef = eventfs_prepare_ef(name, mode, fop, NULL, data); - - if (IS_ERR(ef)) - return -ENOMEM; - - mutex_lock(&eventfs_mutex); - list_add_tail(&ef->list, &ei->e_top_files); - ef->d_parent = parent; - mutex_unlock(&eventfs_mutex); - return 0; + struct eventfs_inode *ei, *tmp; + struct llist_node *llnode; + + llnode = llist_del_all(&free_list); + llist_for_each_entry_safe(ei, tmp, llnode, llist) { + /* This dput() matches the dget() from unhook_dentry() */ + for (int i = 0; i < ei->nr_entries; i++) { + if (ei->d_children[i]) + dput(ei->d_children[i]); + } + /* This should only get here if it had a dentry */ + if (!WARN_ON_ONCE(!ei->dentry)) + dput(ei->dentry); + } } -/** - * eventfs_add_file - add eventfs file to list to create later - * @name: the name of the file to create. - * @mode: the permission that the file should have. - * @ef_parent: parent eventfs_file for this file. - * @data: something that the caller will want to get to later on. - * @fop: struct file_operations that should be used for this file. - * - * This function is used to add the information needed to create a - * file within a subdirectory of the events directory. The file created - * will have the @mode permissions. The @data will be used to fill the - * inode.i_private when the open() call is done. The dentry and inodes are - * all created when they are referenced, and removed when they are no - * longer referenced. - */ -int eventfs_add_file(const char *name, umode_t mode, - struct eventfs_file *ef_parent, - void *data, - const struct file_operations *fop) -{ - struct eventfs_file *ef; - - if (security_locked_down(LOCKDOWN_TRACEFS)) - return -ENODEV; +static DECLARE_WORK(eventfs_work, eventfs_workfn); - if (!ef_parent) - return -EINVAL; +static void free_rcu_ei(struct rcu_head *head) +{ + struct eventfs_inode *ei = container_of(head, struct eventfs_inode, rcu); - if (!(mode & S_IFMT)) - mode |= S_IFREG; + if (ei->dentry) { + /* Do not free the ei until all references of dentry are gone */ + if (llist_add(&ei->llist, &free_list)) + queue_work(system_unbound_wq, &eventfs_work); + return; + } - ef = eventfs_prepare_ef(name, mode, fop, NULL, data); - if (IS_ERR(ef)) - return -ENOMEM; + /* If the ei doesn't have a dentry, neither should its children */ + for (int i = 0; i < ei->nr_entries; i++) { + WARN_ON_ONCE(ei->d_children[i]); + } - mutex_lock(&eventfs_mutex); - list_add_tail(&ef->list, &ef_parent->ei->e_top_files); - ef->d_parent = ef_parent->dentry; - mutex_unlock(&eventfs_mutex); - return 0; + free_ei(ei); } -static void free_ef(struct rcu_head *head) +static void unhook_dentry(struct dentry *dentry) { - struct eventfs_file *ef = container_of(head, struct eventfs_file, rcu); + if (!dentry) + return; + /* + * Need to add a reference to the dentry that is expected by + * simple_recursive_removal(), which will include a dput(). + */ + dget(dentry); - kfree(ef->name); - kfree(ef->ei); - kfree(ef); + /* + * Also add a reference for the dput() in eventfs_workfn(). + * That is required as that dput() will free the ei after + * the SRCU grace period is over. + */ + dget(dentry); } /** * eventfs_remove_rec - remove eventfs dir or file from list - * @ef: eventfs_file to be removed. - * @head: to create list of eventfs_file to be deleted - * @level: to check recursion depth + * @ei: eventfs_inode to be removed. + * @level: prevent recursion from going more than 3 levels deep. * - * The helper function eventfs_remove_rec() is used to clean up and free the - * associated data from eventfs for both of the added functions. + * This function recursively removes eventfs_inodes which + * contains info of files and/or directories. */ -static void eventfs_remove_rec(struct eventfs_file *ef, struct list_head *head, int level) +static void eventfs_remove_rec(struct eventfs_inode *ei, int level) { - struct eventfs_file *ef_child; + struct eventfs_inode *ei_child; - if (!ef) + if (!ei) return; /* * Check recursion depth. It should never be greater than 3: @@ -806,100 +1005,76 @@ static void eventfs_remove_rec(struct eventfs_file *ef, struct list_head *head, if (WARN_ON_ONCE(level > 3)) return; - if (ef->ei) { - /* search for nested folders or files */ - list_for_each_entry_srcu(ef_child, &ef->ei->e_top_files, list, - lockdep_is_held(&eventfs_mutex)) { - eventfs_remove_rec(ef_child, head, level + 1); + /* search for nested folders or files */ + list_for_each_entry_srcu(ei_child, &ei->children, list, + lockdep_is_held(&eventfs_mutex)) { + /* Children only have dentry if parent does */ + WARN_ON_ONCE(ei_child->dentry && !ei->dentry); + eventfs_remove_rec(ei_child, level + 1); + } + + + ei->is_freed = 1; + + for (int i = 0; i < ei->nr_entries; i++) { + if (ei->d_children[i]) { + /* Children only have dentry if parent does */ + WARN_ON_ONCE(!ei->dentry); + unhook_dentry(ei->d_children[i]); } } - list_del_rcu(&ef->list); - list_add_tail(&ef->del_list, head); + unhook_dentry(ei->dentry); + + list_del_rcu(&ei->list); + call_srcu(&eventfs_srcu, &ei->rcu, free_rcu_ei); } /** - * eventfs_remove - remove eventfs dir or file from list - * @ef: eventfs_file to be removed. + * eventfs_remove_dir - remove eventfs dir or file from list + * @ei: eventfs_inode to be removed. * * This function acquire the eventfs_mutex lock and call eventfs_remove_rec() */ -void eventfs_remove(struct eventfs_file *ef) +void eventfs_remove_dir(struct eventfs_inode *ei) { - struct eventfs_file *tmp; - LIST_HEAD(ef_del_list); - struct dentry *dentry_list = NULL; struct dentry *dentry; - if (!ef) + if (!ei) return; mutex_lock(&eventfs_mutex); - eventfs_remove_rec(ef, &ef_del_list, 0); - list_for_each_entry_safe(ef, tmp, &ef_del_list, del_list) { - if (ef->dentry) { - unsigned long ptr = (unsigned long)dentry_list; - - /* Keep the dentry from being freed yet */ - dget(ef->dentry); - - /* - * Paranoid: The dget() above should prevent the dentry - * from being freed and calling eventfs_set_ef_status_free(). - * But just in case, set the link list LSB pointer to 1 - * and have eventfs_set_ef_status_free() check that to - * make sure that if it does happen, it will not think - * the d_fsdata is an event_file. - * - * For this to work, no event_file should be allocated - * on a odd space, as the ef should always be allocated - * to be at least word aligned. Check for that too. - */ - WARN_ON_ONCE(ptr & 1); - - ef->dentry->d_fsdata = (void *)(ptr | 1); - dentry_list = ef->dentry; - ef->dentry = NULL; - } - call_srcu(&eventfs_srcu, &ef->rcu, free_ef); - } + dentry = ei->dentry; + eventfs_remove_rec(ei, 0); mutex_unlock(&eventfs_mutex); - while (dentry_list) { - unsigned long ptr; - - dentry = dentry_list; - ptr = (unsigned long)dentry->d_fsdata & ~1UL; - dentry_list = (struct dentry *)ptr; - dentry->d_fsdata = NULL; - d_invalidate(dentry); - mutex_lock(&eventfs_mutex); - /* dentry should now have at least a single reference */ - WARN_ONCE((int)d_count(dentry) < 1, - "dentry %p less than one reference (%d) after invalidate\n", - dentry, d_count(dentry)); - mutex_unlock(&eventfs_mutex); - dput(dentry); - } + /* + * If any of the ei children has a dentry, then the ei itself + * must have a dentry. + */ + if (dentry) + simple_recursive_removal(dentry, NULL); } /** - * eventfs_remove_events_dir - remove eventfs dir or file from list - * @dentry: events's dentry to be removed. + * eventfs_remove_events_dir - remove the top level eventfs directory + * @ei: the event_inode returned by eventfs_create_events_dir(). * - * This function remove events main directory + * This function removes the events main directory */ -void eventfs_remove_events_dir(struct dentry *dentry) +void eventfs_remove_events_dir(struct eventfs_inode *ei) { - struct tracefs_inode *ti; - - if (!dentry || !dentry->d_inode) - return; + struct dentry *dentry; - ti = get_tracefs(dentry->d_inode); - if (!ti || !(ti->flags & TRACEFS_EVENT_INODE)) - return; + dentry = ei->dentry; + eventfs_remove_dir(ei); - d_invalidate(dentry); + /* + * Matches the dget() done by tracefs_start_creating() + * in eventfs_create_events_dir() when it the dentry was + * created. In other words, it's a normal dentry that + * sticks around while the other ei->dentry are created + * and destroyed dynamically. + */ dput(dentry); } diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c index 429603d865a9..5b54948514fe 100644 --- a/fs/tracefs/inode.c +++ b/fs/tracefs/inode.c @@ -385,7 +385,7 @@ static void tracefs_dentry_iput(struct dentry *dentry, struct inode *inode) ti = get_tracefs(inode); if (ti && ti->flags & TRACEFS_EVENT_INODE) - eventfs_set_ef_status_free(ti, dentry); + eventfs_set_ei_status_free(ti, dentry); iput(inode); } diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h index 4f2e49e2197b..ccee18ca66c7 100644 --- a/fs/tracefs/internal.h +++ b/fs/tracefs/internal.h @@ -13,6 +13,58 @@ struct tracefs_inode { struct inode vfs_inode; }; +/* + * struct eventfs_attr - cache the mode and ownership of a eventfs entry + * @mode: saved mode plus flags of what is saved + * @uid: saved uid if changed + * @gid: saved gid if changed + */ +struct eventfs_attr { + int mode; + kuid_t uid; + kgid_t gid; +}; + +/* + * struct eventfs_inode - hold the properties of the eventfs directories. + * @list: link list into the parent directory + * @entries: the array of entries representing the files in the directory + * @name: the name of the directory to create + * @children: link list into the child eventfs_inode + * @dentry: the dentry of the directory + * @d_parent: pointer to the parent's dentry + * @d_children: The array of dentries to represent the files when created + * @entry_attrs: Saved mode and ownership of the @d_children + * @attr: Saved mode and ownership of eventfs_inode itself + * @data: The private data to pass to the callbacks + * @is_freed: Flag set if the eventfs is on its way to be freed + * Note if is_freed is set, then dentry is corrupted. + * @nr_entries: The number of items in @entries + */ +struct eventfs_inode { + struct list_head list; + const struct eventfs_entry *entries; + const char *name; + struct list_head children; + struct dentry *dentry; /* Check is_freed to access */ + struct dentry *d_parent; + struct dentry **d_children; + struct eventfs_attr *entry_attrs; + struct eventfs_attr attr; + void *data; + /* + * Union - used for deletion + * @llist: for calling dput() if needed after RCU + * @rcu: eventfs_inode to delete in RCU + */ + union { + struct llist_node llist; + struct rcu_head rcu; + }; + unsigned int is_freed:1; + unsigned int nr_entries:31; +}; + static inline struct tracefs_inode *get_tracefs(const struct inode *inode) { return container_of(inode, struct tracefs_inode, vfs_inode); @@ -25,6 +77,6 @@ struct inode *tracefs_get_inode(struct super_block *sb); struct dentry *eventfs_start_creating(const char *name, struct dentry *parent); struct dentry *eventfs_failed_creating(struct dentry *dentry); struct dentry *eventfs_end_creating(struct dentry *dentry); -void eventfs_set_ef_status_free(struct tracefs_inode *ti, struct dentry *dentry); +void eventfs_set_ei_status_free(struct tracefs_inode *ti, struct dentry *dentry); #endif /* _TRACEFS_INTERNAL_H */ diff --git a/include/linux/seq_buf.h b/include/linux/seq_buf.h index 515d7fcb9634..5fb1f12c33f9 100644 --- a/include/linux/seq_buf.h +++ b/include/linux/seq_buf.h @@ -14,19 +14,25 @@ * @buffer: pointer to the buffer * @size: size of the buffer * @len: the amount of data inside the buffer - * @readpos: The next position to read in the buffer. */ struct seq_buf { char *buffer; size_t size; size_t len; - loff_t readpos; }; +#define DECLARE_SEQ_BUF(NAME, SIZE) \ + char __ ## NAME ## _buffer[SIZE] = ""; \ + struct seq_buf NAME = { \ + .buffer = &__ ## NAME ## _buffer, \ + .size = SIZE, \ + } + static inline void seq_buf_clear(struct seq_buf *s) { s->len = 0; - s->readpos = 0; + if (s->size) + s->buffer[0] = '\0'; } static inline void @@ -39,7 +45,7 @@ seq_buf_init(struct seq_buf *s, char *buf, unsigned int size) /* * seq_buf have a buffer that might overflow. When this happens - * the len and size are set to be equal. + * len is set to be greater than size. */ static inline bool seq_buf_has_overflowed(struct seq_buf *s) @@ -72,8 +78,8 @@ static inline unsigned int seq_buf_used(struct seq_buf *s) } /** - * seq_buf_terminate - Make sure buffer is nul terminated - * @s: the seq_buf descriptor to terminate. + * seq_buf_str - get %NUL-terminated C string from seq_buf + * @s: the seq_buf handle * * This makes sure that the buffer in @s is nul terminated and * safe to read as a string. @@ -84,16 +90,20 @@ static inline unsigned int seq_buf_used(struct seq_buf *s) * * After this function is called, s->buffer is safe to use * in string operations. + * + * Returns @s->buf after making sure it is terminated. */ -static inline void seq_buf_terminate(struct seq_buf *s) +static inline const char *seq_buf_str(struct seq_buf *s) { if (WARN_ON(s->size == 0)) - return; + return ""; if (seq_buf_buffer_left(s)) s->buffer[s->len] = 0; else s->buffer[s->size - 1] = 0; + + return s->buffer; } /** @@ -143,7 +153,7 @@ extern __printf(2, 0) int seq_buf_vprintf(struct seq_buf *s, const char *fmt, va_list args); extern int seq_buf_print_seq(struct seq_file *m, struct seq_buf *s); extern int seq_buf_to_user(struct seq_buf *s, char __user *ubuf, - int cnt); + size_t start, int cnt); extern int seq_buf_puts(struct seq_buf *s, const char *str); extern int seq_buf_putc(struct seq_buf *s, unsigned char c); extern int seq_buf_putmem(struct seq_buf *s, const void *mem, unsigned int len); diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 5eb88a66eb68..d68ff9b1247f 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -492,6 +492,7 @@ enum { EVENT_FILE_FL_TRIGGER_COND_BIT, EVENT_FILE_FL_PID_FILTER_BIT, EVENT_FILE_FL_WAS_ENABLED_BIT, + EVENT_FILE_FL_FREED_BIT, }; extern struct trace_event_file *trace_get_event_file(const char *instance, @@ -630,6 +631,7 @@ extern int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...); * TRIGGER_COND - When set, one or more triggers has an associated filter * PID_FILTER - When set, the event is filtered based on pid * WAS_ENABLED - Set when enabled to know to clear trace on module removal + * FREED - File descriptor is freed, all fields should be considered invalid */ enum { EVENT_FILE_FL_ENABLED = (1 << EVENT_FILE_FL_ENABLED_BIT), @@ -643,13 +645,14 @@ enum { EVENT_FILE_FL_TRIGGER_COND = (1 << EVENT_FILE_FL_TRIGGER_COND_BIT), EVENT_FILE_FL_PID_FILTER = (1 << EVENT_FILE_FL_PID_FILTER_BIT), EVENT_FILE_FL_WAS_ENABLED = (1 << EVENT_FILE_FL_WAS_ENABLED_BIT), + EVENT_FILE_FL_FREED = (1 << EVENT_FILE_FL_FREED_BIT), }; struct trace_event_file { struct list_head list; struct trace_event_call *event_call; struct event_filter __rcu *filter; - struct eventfs_file *ef; + struct eventfs_inode *ei; struct trace_array *tr; struct trace_subsystem_dir *system; struct list_head triggers; @@ -671,6 +674,7 @@ struct trace_event_file { * caching and such. Which is mostly OK ;-) */ unsigned long flags; + atomic_t ref; /* ref count for opened files */ atomic_t sm_ref; /* soft-mode reference counter */ atomic_t tm_ref; /* trigger-mode reference counter */ }; diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h index 6be92bf559fe..3691e0e76a1a 100644 --- a/include/linux/trace_seq.h +++ b/include/linux/trace_seq.h @@ -14,6 +14,7 @@ struct trace_seq { char buffer[PAGE_SIZE]; struct seq_buf seq; + size_t readpos; int full; }; @@ -22,6 +23,7 @@ trace_seq_init(struct trace_seq *s) { seq_buf_init(&s->seq, s->buffer, PAGE_SIZE); s->full = 0; + s->readpos = 0; } /** diff --git a/include/linux/tracefs.h b/include/linux/tracefs.h index 009072792fa3..7a5fe17b6bf9 100644 --- a/include/linux/tracefs.h +++ b/include/linux/tracefs.h @@ -23,26 +23,69 @@ struct file_operations; struct eventfs_file; -struct dentry *eventfs_create_events_dir(const char *name, - struct dentry *parent); - -struct eventfs_file *eventfs_add_subsystem_dir(const char *name, - struct dentry *parent); +/** + * eventfs_callback - A callback function to create dynamic files in eventfs + * @name: The name of the file that is to be created + * @mode: return the file mode for the file (RW access, etc) + * @data: data to pass to the created file ops + * @fops: the file operations of the created file + * + * The evetnfs files are dynamically created. The struct eventfs_entry array + * is passed to eventfs_create_dir() or eventfs_create_events_dir() that will + * be used to create the files within those directories. When a lookup + * or access to a file within the directory is made, the struct eventfs_entry + * array is used to find a callback() with the matching name that is being + * referenced (for lookups, the entire array is iterated and each callback + * will be called). + * + * The callback will be called with @name for the name of the file to create. + * The callback can return less than 1 to indicate that no file should be + * created. + * + * If a file is to be created, then @mode should be populated with the file + * mode (permissions) for which the file is created for. This would be + * used to set the created inode i_mode field. + * + * The @data should be set to the data passed to the other file operations + * (read, write, etc). Note, @data will also point to the data passed in + * to eventfs_create_dir() or eventfs_create_events_dir(), but the callback + * can replace the data if it chooses to. Otherwise, the original data + * will be used for the file operation functions. + * + * The @fops should be set to the file operations that will be used to create + * the inode. + * + * NB. This callback is called while holding internal locks of the eventfs + * system. The callback must not call any code that might also call into + * the tracefs or eventfs system or it will risk creating a deadlock. + */ +typedef int (*eventfs_callback)(const char *name, umode_t *mode, void **data, + const struct file_operations **fops); -struct eventfs_file *eventfs_add_dir(const char *name, - struct eventfs_file *ef_parent); +/** + * struct eventfs_entry - dynamically created eventfs file call back handler + * @name: Then name of the dynamic file in an eventfs directory + * @callback: The callback to get the fops of the file when it is created + * + * See evenfs_callback() typedef for how to set up @callback. + */ +struct eventfs_entry { + const char *name; + eventfs_callback callback; +}; -int eventfs_add_file(const char *name, umode_t mode, - struct eventfs_file *ef_parent, void *data, - const struct file_operations *fops); +struct eventfs_inode; -int eventfs_add_events_file(const char *name, umode_t mode, - struct dentry *parent, void *data, - const struct file_operations *fops); +struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry *parent, + const struct eventfs_entry *entries, + int size, void *data); -void eventfs_remove(struct eventfs_file *ef); +struct eventfs_inode *eventfs_create_dir(const char *name, struct eventfs_inode *parent, + const struct eventfs_entry *entries, + int size, void *data); -void eventfs_remove_events_dir(struct dentry *dentry); +void eventfs_remove_events_dir(struct eventfs_inode *ei); +void eventfs_remove_dir(struct eventfs_inode *ei); struct dentry *tracefs_create_file(const char *name, umode_t mode, struct dentry *parent, void *data, diff --git a/include/uapi/linux/user_events.h b/include/uapi/linux/user_events.h index 2984aae4a2b4..f74f3aedd49c 100644 --- a/include/uapi/linux/user_events.h +++ b/include/uapi/linux/user_events.h @@ -17,6 +17,15 @@ /* Create dynamic location entry within a 32-bit value */ #define DYN_LOC(offset, size) ((size) << 16 | (offset)) +/* List of supported registration flags */ +enum user_reg_flag { + /* Event will not delete upon last reference closing */ + USER_EVENT_REG_PERSIST = 1U << 0, + + /* This value or above is currently non-ABI */ + USER_EVENT_REG_MAX = 1U << 1, +}; + /* * Describes an event registration and stores the results of the registration. * This structure is passed to the DIAG_IOCSREG ioctl, callers at a minimum @@ -33,7 +42,7 @@ struct user_reg { /* Input: Enable size in bytes at address */ __u8 enable_size; - /* Input: Flags for future use, set to 0 */ + /* Input: Flags to use, if any */ __u16 flags; /* Input: Address to update when enabled */ diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 515cafdb18d9..43cc47d7faaf 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2056,7 +2056,7 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer) retries = 10; success = false; while (retries--) { - struct list_head *head_page, *prev_page, *r; + struct list_head *head_page, *prev_page; struct list_head *last_page, *first_page; struct list_head *head_page_with_bit; struct buffer_page *hpage = rb_set_head_page(cpu_buffer); @@ -2075,9 +2075,9 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer) last_page->next = head_page_with_bit; first_page->prev = prev_page; - r = cmpxchg(&prev_page->next, head_page_with_bit, first_page); - - if (r == head_page_with_bit) { + /* caution: head_page_with_bit gets updated on cmpxchg failure */ + if (try_cmpxchg(&prev_page->next, + &head_page_with_bit, first_page)) { /* * yay, we replaced the page pointer to our new list, * now, we just have to update to head page's prev diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index abaaf516fcae..9aebf904ff97 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -54,12 +54,6 @@ #include "trace.h" #include "trace_output.h" -/* - * On boot up, the ring buffer is set to the minimum size, so that - * we do not waste memory on systems that are not using tracing. - */ -bool ring_buffer_expanded; - #ifdef CONFIG_FTRACE_STARTUP_TEST /* * We need to change this state when a selftest is running. @@ -202,7 +196,7 @@ static int __init set_cmdline_ftrace(char *str) strscpy(bootup_tracer_buf, str, MAX_TRACER_SIZE); default_bootup_tracer = bootup_tracer_buf; /* We are using ftrace early, expand it */ - ring_buffer_expanded = true; + trace_set_ring_buffer_expanded(NULL); return 1; } __setup("ftrace=", set_cmdline_ftrace); @@ -247,7 +241,7 @@ static int __init boot_alloc_snapshot(char *str) } else { allocate_snapshot = true; /* We also need the main ring buffer expanded */ - ring_buffer_expanded = true; + trace_set_ring_buffer_expanded(NULL); } return 1; } @@ -490,6 +484,13 @@ static struct trace_array global_trace = { .trace_flags = TRACE_DEFAULT_FLAGS, }; +void trace_set_ring_buffer_expanded(struct trace_array *tr) +{ + if (!tr) + tr = &global_trace; + tr->ring_buffer_expanded = true; +} + LIST_HEAD(ftrace_trace_arrays); int trace_array_get(struct trace_array *this_tr) @@ -1730,15 +1731,15 @@ static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt) { int len; - if (trace_seq_used(s) <= s->seq.readpos) + if (trace_seq_used(s) <= s->readpos) return -EBUSY; - len = trace_seq_used(s) - s->seq.readpos; + len = trace_seq_used(s) - s->readpos; if (cnt > len) cnt = len; - memcpy(buf, s->buffer + s->seq.readpos, cnt); + memcpy(buf, s->buffer + s->readpos, cnt); - s->seq.readpos += cnt; + s->readpos += cnt; return cnt; } @@ -2012,7 +2013,7 @@ static int run_tracer_selftest(struct tracer *type) #ifdef CONFIG_TRACER_MAX_TRACE if (type->use_max_tr) { /* If we expanded the buffers, make sure the max is expanded too */ - if (ring_buffer_expanded) + if (tr->ring_buffer_expanded) ring_buffer_resize(tr->max_buffer.buffer, trace_buf_size, RING_BUFFER_ALL_CPUS); tr->allocated_snapshot = true; @@ -2038,7 +2039,7 @@ static int run_tracer_selftest(struct tracer *type) tr->allocated_snapshot = false; /* Shrink the max buffer again */ - if (ring_buffer_expanded) + if (tr->ring_buffer_expanded) ring_buffer_resize(tr->max_buffer.buffer, 1, RING_BUFFER_ALL_CPUS); } @@ -3403,7 +3404,7 @@ void trace_printk_init_buffers(void) pr_warn("**********************************************************\n"); /* Expand the buffers to set size */ - tracing_update_buffers(); + tracing_update_buffers(&global_trace); buffers_allocated = 1; @@ -3827,15 +3828,6 @@ static bool trace_safe_str(struct trace_iterator *iter, const char *str, return false; } -static const char *show_buffer(struct trace_seq *s) -{ - struct seq_buf *seq = &s->seq; - - seq_buf_terminate(seq); - - return seq->buffer; -} - static DEFINE_STATIC_KEY_FALSE(trace_no_verify); static int test_can_verify_check(const char *fmt, ...) @@ -3975,7 +3967,7 @@ void trace_check_vprintf(struct trace_iterator *iter, const char *fmt, */ if (WARN_ONCE(!trace_safe_str(iter, str, star, len), "fmt: '%s' current_buffer: '%s'", - fmt, show_buffer(&iter->seq))) { + fmt, seq_buf_str(&iter->seq.seq))) { int ret; /* Try to safely read the string */ @@ -4986,6 +4978,20 @@ int tracing_open_file_tr(struct inode *inode, struct file *filp) if (ret) return ret; + mutex_lock(&event_mutex); + + /* Fail if the file is marked for removal */ + if (file->flags & EVENT_FILE_FL_FREED) { + trace_array_put(file->tr); + ret = -ENODEV; + } else { + event_file_get(file); + } + + mutex_unlock(&event_mutex); + if (ret) + return ret; + filp->private_data = inode->i_private; return 0; @@ -4996,6 +5002,7 @@ int tracing_release_file_tr(struct inode *inode, struct file *filp) struct trace_event_file *file = inode->i_private; trace_array_put(file->tr); + event_file_put(file); return 0; } @@ -6374,7 +6381,7 @@ static int __tracing_resize_ring_buffer(struct trace_array *tr, * we use the size that was given, and we can forget about * expanding it later. */ - ring_buffer_expanded = true; + trace_set_ring_buffer_expanded(tr); /* May be called before buffers are initialized */ if (!tr->array_buffer.buffer) @@ -6452,6 +6459,7 @@ out: /** * tracing_update_buffers - used by tracing facility to expand ring buffers + * @tr: The tracing instance * * To save on memory when the tracing is never used on a system with it * configured in. The ring buffers are set to a minimum size. But once @@ -6460,13 +6468,13 @@ out: * * This function is to be called when a tracer is about to be used. */ -int tracing_update_buffers(void) +int tracing_update_buffers(struct trace_array *tr) { int ret = 0; mutex_lock(&trace_types_lock); - if (!ring_buffer_expanded) - ret = __tracing_resize_ring_buffer(&global_trace, trace_buf_size, + if (!tr->ring_buffer_expanded) + ret = __tracing_resize_ring_buffer(tr, trace_buf_size, RING_BUFFER_ALL_CPUS); mutex_unlock(&trace_types_lock); @@ -6520,7 +6528,7 @@ int tracing_set_tracer(struct trace_array *tr, const char *buf) mutex_lock(&trace_types_lock); - if (!ring_buffer_expanded) { + if (!tr->ring_buffer_expanded) { ret = __tracing_resize_ring_buffer(tr, trace_buf_size, RING_BUFFER_ALL_CPUS); if (ret < 0) @@ -7006,7 +7014,7 @@ waitagain: /* Now copy what we have to the user */ sret = trace_seq_to_user(&iter->seq, ubuf, cnt); - if (iter->seq.seq.readpos >= trace_seq_used(&iter->seq)) + if (iter->seq.readpos >= trace_seq_used(&iter->seq)) trace_seq_init(&iter->seq); /* @@ -7192,7 +7200,7 @@ tracing_entries_read(struct file *filp, char __user *ubuf, } if (buf_size_same) { - if (!ring_buffer_expanded) + if (!tr->ring_buffer_expanded) r = sprintf(buf, "%lu (expanded: %lu)\n", size >> 10, trace_buf_size >> 10); @@ -7249,10 +7257,10 @@ tracing_total_entries_read(struct file *filp, char __user *ubuf, mutex_lock(&trace_types_lock); for_each_tracing_cpu(cpu) { size += per_cpu_ptr(tr->array_buffer.data, cpu)->entries >> 10; - if (!ring_buffer_expanded) + if (!tr->ring_buffer_expanded) expanded_size += trace_buf_size >> 10; } - if (ring_buffer_expanded) + if (tr->ring_buffer_expanded) r = sprintf(buf, "%lu\n", size); else r = sprintf(buf, "%lu (expanded: %lu)\n", size, expanded_size); @@ -7646,7 +7654,7 @@ tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt, unsigned long val; int ret; - ret = tracing_update_buffers(); + ret = tracing_update_buffers(tr); if (ret < 0) return ret; @@ -9550,6 +9558,9 @@ static struct trace_array *trace_array_create(const char *name) if (allocate_trace_buffers(tr, trace_buf_size) < 0) goto out_free_tr; + /* The ring buffer is defaultly expanded */ + trace_set_ring_buffer_expanded(tr); + if (ftrace_allocate_ftrace_ops(tr) < 0) goto out_free_tr; @@ -9759,7 +9770,6 @@ static __init void create_trace_instances(struct dentry *d_tracer) static void init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) { - struct trace_event_file *file; int cpu; trace_create_file("available_tracers", TRACE_MODE_READ, d_tracer, @@ -9792,11 +9802,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) trace_create_file("trace_marker", 0220, d_tracer, tr, &tracing_mark_fops); - file = __find_event_file(tr, "ftrace", "print"); - if (file && file->ef) - eventfs_add_file("trigger", TRACE_MODE_WRITE, file->ef, - file, &event_trigger_fops); - tr->trace_marker_file = file; + tr->trace_marker_file = __find_event_file(tr, "ftrace", "print"); trace_create_file("trace_marker_raw", 0220, d_tracer, tr, &tracing_mark_raw_fops); @@ -10444,7 +10450,7 @@ __init static int tracer_alloc_buffers(void) trace_printk_init_buffers(); /* To save memory, keep the ring buffer size to its minimum */ - if (ring_buffer_expanded) + if (global_trace.ring_buffer_expanded) ring_buf_size = trace_buf_size; else ring_buf_size = 1; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 77debe53f07c..b7f4ea25a194 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -381,7 +381,7 @@ struct trace_array { struct dentry *dir; struct dentry *options; struct dentry *percpu_dir; - struct dentry *event_dir; + struct eventfs_inode *event_dir; struct trace_options *topts; struct list_head systems; struct list_head events; @@ -410,6 +410,11 @@ struct trace_array { struct cond_snapshot *cond_snapshot; #endif struct trace_func_repeats __percpu *last_func_repeats; + /* + * On boot up, the ring buffer is set to the minimum size, so that + * we do not waste memory on systems that are not using tracing. + */ + bool ring_buffer_expanded; }; enum { @@ -761,7 +766,7 @@ extern int DYN_FTRACE_TEST_NAME(void); #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2 extern int DYN_FTRACE_TEST_NAME2(void); -extern bool ring_buffer_expanded; +extern void trace_set_ring_buffer_expanded(struct trace_array *tr); extern bool tracing_selftest_disabled; #ifdef CONFIG_FTRACE_STARTUP_TEST @@ -1305,7 +1310,7 @@ static inline void trace_branch_disable(void) #endif /* CONFIG_BRANCH_TRACER */ /* set ring buffers to default size if not already done so */ -int tracing_update_buffers(void); +int tracing_update_buffers(struct trace_array *tr); union trace_synth_field { u8 as_u8; @@ -1344,7 +1349,7 @@ struct trace_subsystem_dir { struct list_head list; struct event_subsystem *subsystem; struct trace_array *tr; - struct eventfs_file *ef; + struct eventfs_inode *ei; int ref_count; int nr_events; }; @@ -1664,6 +1669,9 @@ extern void event_trigger_unregister(struct event_command *cmd_ops, char *glob, struct event_trigger_data *trigger_data); +extern void event_file_get(struct trace_event_file *file); +extern void event_file_put(struct trace_event_file *file); + /** * struct event_trigger_ops - callbacks for trace event triggers * diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index f49d6ddb6342..f29e815ca5b2 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -984,19 +984,41 @@ static void remove_subsystem(struct trace_subsystem_dir *dir) return; if (!--dir->nr_events) { - eventfs_remove(dir->ef); + eventfs_remove_dir(dir->ei); list_del(&dir->list); __put_system_dir(dir); } } +void event_file_get(struct trace_event_file *file) +{ + atomic_inc(&file->ref); +} + +void event_file_put(struct trace_event_file *file) +{ + if (WARN_ON_ONCE(!atomic_read(&file->ref))) { + if (file->flags & EVENT_FILE_FL_FREED) + kmem_cache_free(file_cachep, file); + return; + } + + if (atomic_dec_and_test(&file->ref)) { + /* Count should only go to zero when it is freed */ + if (WARN_ON_ONCE(!(file->flags & EVENT_FILE_FL_FREED))) + return; + kmem_cache_free(file_cachep, file); + } +} + static void remove_event_file_dir(struct trace_event_file *file) { - eventfs_remove(file->ef); + eventfs_remove_dir(file->ei); list_del(&file->list); remove_subsystem(file->system); free_event_filter(file->filter); - kmem_cache_free(file_cachep, file); + file->flags |= EVENT_FILE_FL_FREED; + event_file_put(file); } /* @@ -1166,7 +1188,7 @@ ftrace_event_write(struct file *file, const char __user *ubuf, if (!cnt) return 0; - ret = tracing_update_buffers(); + ret = tracing_update_buffers(tr); if (ret < 0) return ret; @@ -1369,7 +1391,7 @@ event_enable_read(struct file *filp, char __user *ubuf, size_t cnt, flags = file->flags; mutex_unlock(&event_mutex); - if (!file) + if (!file || flags & EVENT_FILE_FL_FREED) return -ENODEV; if (flags & EVENT_FILE_FL_ENABLED && @@ -1397,18 +1419,20 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, if (ret) return ret; - ret = tracing_update_buffers(); - if (ret < 0) - return ret; - switch (val) { case 0: case 1: ret = -ENODEV; mutex_lock(&event_mutex); file = event_file_data(filp); - if (likely(file)) + if (likely(file && !(file->flags & EVENT_FILE_FL_FREED))) { + ret = tracing_update_buffers(file->tr); + if (ret < 0) { + mutex_unlock(&event_mutex); + return ret; + } ret = ftrace_event_enable_disable(file, val); + } mutex_unlock(&event_mutex); break; @@ -1482,7 +1506,7 @@ system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, if (ret) return ret; - ret = tracing_update_buffers(); + ret = tracing_update_buffers(dir->tr); if (ret < 0) return ret; @@ -1681,7 +1705,7 @@ event_filter_read(struct file *filp, char __user *ubuf, size_t cnt, mutex_lock(&event_mutex); file = event_file_data(filp); - if (file) + if (file && !(file->flags & EVENT_FILE_FL_FREED)) print_event_filter(file, s); mutex_unlock(&event_mutex); @@ -1956,7 +1980,7 @@ event_pid_write(struct file *filp, const char __user *ubuf, if (!cnt) return 0; - ret = tracing_update_buffers(); + ret = tracing_update_buffers(tr); if (ret < 0) return ret; @@ -2280,14 +2304,40 @@ create_new_subsystem(const char *name) return NULL; } -static struct eventfs_file * +static int system_callback(const char *name, umode_t *mode, void **data, + const struct file_operations **fops) +{ + if (strcmp(name, "filter") == 0) + *fops = &ftrace_subsystem_filter_fops; + + else if (strcmp(name, "enable") == 0) + *fops = &ftrace_system_enable_fops; + + else + return 0; + + *mode = TRACE_MODE_WRITE; + return 1; +} + +static struct eventfs_inode * event_subsystem_dir(struct trace_array *tr, const char *name, - struct trace_event_file *file, struct dentry *parent) + struct trace_event_file *file, struct eventfs_inode *parent) { struct event_subsystem *system, *iter; struct trace_subsystem_dir *dir; - struct eventfs_file *ef; - int res; + struct eventfs_inode *ei; + int nr_entries; + static struct eventfs_entry system_entries[] = { + { + .name = "filter", + .callback = system_callback, + }, + { + .name = "enable", + .callback = system_callback, + } + }; /* First see if we did not already create this dir */ list_for_each_entry(dir, &tr->systems, list) { @@ -2295,7 +2345,7 @@ event_subsystem_dir(struct trace_array *tr, const char *name, if (strcmp(system->name, name) == 0) { dir->nr_events++; file->system = dir; - return dir->ef; + return dir->ei; } } @@ -2319,39 +2369,29 @@ event_subsystem_dir(struct trace_array *tr, const char *name, } else __get_system(system); - ef = eventfs_add_subsystem_dir(name, parent); - if (IS_ERR(ef)) { + /* ftrace only has directories no files */ + if (strcmp(name, "ftrace") == 0) + nr_entries = 0; + else + nr_entries = ARRAY_SIZE(system_entries); + + ei = eventfs_create_dir(name, parent, system_entries, nr_entries, dir); + if (IS_ERR(ei)) { pr_warn("Failed to create system directory %s\n", name); __put_system(system); goto out_free; } - dir->ef = ef; + dir->ei = ei; dir->tr = tr; dir->ref_count = 1; dir->nr_events = 1; dir->subsystem = system; file->system = dir; - /* the ftrace system is special, do not create enable or filter files */ - if (strcmp(name, "ftrace") != 0) { - - res = eventfs_add_file("filter", TRACE_MODE_WRITE, - dir->ef, dir, - &ftrace_subsystem_filter_fops); - if (res) { - kfree(system->filter); - system->filter = NULL; - pr_warn("Could not create tracefs '%s/filter' entry\n", name); - } - - eventfs_add_file("enable", TRACE_MODE_WRITE, dir->ef, dir, - &ftrace_system_enable_fops); - } - list_add(&dir->list, &tr->systems); - return dir->ef; + return dir->ei; out_free: kfree(dir); @@ -2400,15 +2440,134 @@ event_define_fields(struct trace_event_call *call) return ret; } +static int event_callback(const char *name, umode_t *mode, void **data, + const struct file_operations **fops) +{ + struct trace_event_file *file = *data; + struct trace_event_call *call = file->event_call; + + if (strcmp(name, "format") == 0) { + *mode = TRACE_MODE_READ; + *fops = &ftrace_event_format_fops; + *data = call; + return 1; + } + + /* + * Only event directories that can be enabled should have + * triggers or filters, with the exception of the "print" + * event that can have a "trigger" file. + */ + if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) { + if (call->class->reg && strcmp(name, "enable") == 0) { + *mode = TRACE_MODE_WRITE; + *fops = &ftrace_enable_fops; + return 1; + } + + if (strcmp(name, "filter") == 0) { + *mode = TRACE_MODE_WRITE; + *fops = &ftrace_event_filter_fops; + return 1; + } + } + + if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) || + strcmp(trace_event_name(call), "print") == 0) { + if (strcmp(name, "trigger") == 0) { + *mode = TRACE_MODE_WRITE; + *fops = &event_trigger_fops; + return 1; + } + } + +#ifdef CONFIG_PERF_EVENTS + if (call->event.type && call->class->reg && + strcmp(name, "id") == 0) { + *mode = TRACE_MODE_READ; + *data = (void *)(long)call->event.type; + *fops = &ftrace_event_id_fops; + return 1; + } +#endif + +#ifdef CONFIG_HIST_TRIGGERS + if (strcmp(name, "hist") == 0) { + *mode = TRACE_MODE_READ; + *fops = &event_hist_fops; + return 1; + } +#endif +#ifdef CONFIG_HIST_TRIGGERS_DEBUG + if (strcmp(name, "hist_debug") == 0) { + *mode = TRACE_MODE_READ; + *fops = &event_hist_debug_fops; + return 1; + } +#endif +#ifdef CONFIG_TRACE_EVENT_INJECT + if (call->event.type && call->class->reg && + strcmp(name, "inject") == 0) { + *mode = 0200; + *fops = &event_inject_fops; + return 1; + } +#endif + return 0; +} + static int -event_create_dir(struct dentry *parent, struct trace_event_file *file) +event_create_dir(struct eventfs_inode *parent, struct trace_event_file *file) { struct trace_event_call *call = file->event_call; - struct eventfs_file *ef_subsystem = NULL; struct trace_array *tr = file->tr; - struct eventfs_file *ef; + struct eventfs_inode *e_events; + struct eventfs_inode *ei; const char *name; + int nr_entries; int ret; + static struct eventfs_entry event_entries[] = { + { + .name = "enable", + .callback = event_callback, + }, + { + .name = "filter", + .callback = event_callback, + }, + { + .name = "trigger", + .callback = event_callback, + }, + { + .name = "format", + .callback = event_callback, + }, +#ifdef CONFIG_PERF_EVENTS + { + .name = "id", + .callback = event_callback, + }, +#endif +#ifdef CONFIG_HIST_TRIGGERS + { + .name = "hist", + .callback = event_callback, + }, +#endif +#ifdef CONFIG_HIST_TRIGGERS_DEBUG + { + .name = "hist_debug", + .callback = event_callback, + }, +#endif +#ifdef CONFIG_TRACE_EVENT_INJECT + { + .name = "inject", + .callback = event_callback, + }, +#endif + }; /* * If the trace point header did not define TRACE_SYSTEM @@ -2418,29 +2577,20 @@ event_create_dir(struct dentry *parent, struct trace_event_file *file) if (WARN_ON_ONCE(strcmp(call->class->system, TRACE_SYSTEM) == 0)) return -ENODEV; - ef_subsystem = event_subsystem_dir(tr, call->class->system, file, parent); - if (!ef_subsystem) + e_events = event_subsystem_dir(tr, call->class->system, file, parent); + if (!e_events) return -ENOMEM; + nr_entries = ARRAY_SIZE(event_entries); + name = trace_event_name(call); - ef = eventfs_add_dir(name, ef_subsystem); - if (IS_ERR(ef)) { + ei = eventfs_create_dir(name, e_events, event_entries, nr_entries, file); + if (IS_ERR(ei)) { pr_warn("Could not create tracefs '%s' directory\n", name); return -1; } - file->ef = ef; - - if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) - eventfs_add_file("enable", TRACE_MODE_WRITE, file->ef, file, - &ftrace_enable_fops); - -#ifdef CONFIG_PERF_EVENTS - if (call->event.type && call->class->reg) - eventfs_add_file("id", TRACE_MODE_READ, file->ef, - (void *)(long)call->event.type, - &ftrace_event_id_fops); -#endif + file->ei = ei; ret = event_define_fields(call); if (ret < 0) { @@ -2448,35 +2598,6 @@ event_create_dir(struct dentry *parent, struct trace_event_file *file) return ret; } - /* - * Only event directories that can be enabled should have - * triggers or filters. - */ - if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) { - eventfs_add_file("filter", TRACE_MODE_WRITE, file->ef, - file, &ftrace_event_filter_fops); - - eventfs_add_file("trigger", TRACE_MODE_WRITE, file->ef, - file, &event_trigger_fops); - } - -#ifdef CONFIG_HIST_TRIGGERS - eventfs_add_file("hist", TRACE_MODE_READ, file->ef, file, - &event_hist_fops); -#endif -#ifdef CONFIG_HIST_TRIGGERS_DEBUG - eventfs_add_file("hist_debug", TRACE_MODE_READ, file->ef, file, - &event_hist_debug_fops); -#endif - eventfs_add_file("format", TRACE_MODE_READ, file->ef, call, - &ftrace_event_format_fops); - -#ifdef CONFIG_TRACE_EVENT_INJECT - if (call->event.type && call->class->reg) - eventfs_add_file("inject", 0200, file->ef, file, - &event_inject_fops); -#endif - return 0; } @@ -2803,6 +2924,7 @@ trace_create_new_event(struct trace_event_call *call, atomic_set(&file->tm_ref, 0); INIT_LIST_HEAD(&file->triggers); list_add(&file->list, &tr->events); + event_file_get(file); return file; } @@ -2824,7 +2946,7 @@ static __init int setup_trace_triggers(char *str) int i; strscpy(bootup_trigger_buf, str, COMMAND_LINE_SIZE); - ring_buffer_expanded = true; + trace_set_ring_buffer_expanded(NULL); disable_tracing_selftest("running event triggers"); buf = bootup_trigger_buf; @@ -3614,37 +3736,72 @@ static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata; static __init int setup_trace_event(char *str) { strscpy(bootup_event_buf, str, COMMAND_LINE_SIZE); - ring_buffer_expanded = true; + trace_set_ring_buffer_expanded(NULL); disable_tracing_selftest("running event tracing"); return 1; } __setup("trace_event=", setup_trace_event); +static int events_callback(const char *name, umode_t *mode, void **data, + const struct file_operations **fops) +{ + if (strcmp(name, "enable") == 0) { + *mode = TRACE_MODE_WRITE; + *fops = &ftrace_tr_enable_fops; + return 1; + } + + if (strcmp(name, "header_page") == 0) + *data = ring_buffer_print_page_header; + + else if (strcmp(name, "header_event") == 0) + *data = ring_buffer_print_entry_header; + + else + return 0; + + *mode = TRACE_MODE_READ; + *fops = &ftrace_show_header_fops; + return 1; +} + /* Expects to have event_mutex held when called */ static int create_event_toplevel_files(struct dentry *parent, struct trace_array *tr) { - struct dentry *d_events; + struct eventfs_inode *e_events; struct dentry *entry; - int error = 0; + int nr_entries; + static struct eventfs_entry events_entries[] = { + { + .name = "enable", + .callback = events_callback, + }, + { + .name = "header_page", + .callback = events_callback, + }, + { + .name = "header_event", + .callback = events_callback, + }, + }; entry = trace_create_file("set_event", TRACE_MODE_WRITE, parent, tr, &ftrace_set_event_fops); if (!entry) return -ENOMEM; - d_events = eventfs_create_events_dir("events", parent); - if (IS_ERR(d_events)) { + nr_entries = ARRAY_SIZE(events_entries); + + e_events = eventfs_create_events_dir("events", parent, events_entries, + nr_entries, tr); + if (IS_ERR(e_events)) { pr_warn("Could not create tracefs 'events' directory\n"); return -ENOMEM; } - error = eventfs_add_events_file("enable", TRACE_MODE_WRITE, d_events, - tr, &ftrace_tr_enable_fops); - if (error) - return -ENOMEM; - /* There are not as crucial, just warn if they are not created */ trace_create_file("set_event_pid", TRACE_MODE_WRITE, parent, @@ -3654,16 +3811,7 @@ create_event_toplevel_files(struct dentry *parent, struct trace_array *tr) TRACE_MODE_WRITE, parent, tr, &ftrace_set_event_notrace_pid_fops); - /* ring buffer internal formats */ - eventfs_add_events_file("header_page", TRACE_MODE_READ, d_events, - ring_buffer_print_page_header, - &ftrace_show_header_fops); - - eventfs_add_events_file("header_event", TRACE_MODE_READ, d_events, - ring_buffer_print_entry_header, - &ftrace_show_header_fops); - - tr->event_dir = d_events; + tr->event_dir = e_events; return 0; } diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 33264e510d16..0c611b281a5b 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -2349,6 +2349,9 @@ int apply_event_filter(struct trace_event_file *file, char *filter_string) struct event_filter *filter = NULL; int err; + if (file->flags & EVENT_FILE_FL_FREED) + return -ENODEV; + if (!strcmp(strstrip(filter_string), "0")) { filter_disable(file); filter = event_filter(file); diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index d06938ae0717..1abc07fba1b9 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -774,23 +774,16 @@ static void last_cmd_set(struct trace_event_file *file, char *str) { const char *system = NULL, *name = NULL; struct trace_event_call *call; - int len; if (!str) return; - /* sizeof() contains the nul byte */ - len = sizeof(HIST_PREFIX) + strlen(str); kfree(last_cmd); - last_cmd = kzalloc(len, GFP_KERNEL); + + last_cmd = kasprintf(GFP_KERNEL, HIST_PREFIX "%s", str); if (!last_cmd) return; - strcpy(last_cmd, HIST_PREFIX); - /* Again, sizeof() contains the nul byte */ - len -= sizeof(HIST_PREFIX); - strncat(last_cmd, str, len); - if (file) { call = file->event_call; system = call->class->system; diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index 14cb275a0bab..846e02c0fb59 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -452,7 +452,7 @@ static unsigned int trace_string(struct synth_trace_event *entry, #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE if ((unsigned long)str_val < TASK_SIZE) - ret = strncpy_from_user_nofault(str_field, str_val, STR_VAR_LEN_MAX); + ret = strncpy_from_user_nofault(str_field, (const void __user *)str_val, STR_VAR_LEN_MAX); else #endif ret = strncpy_from_kernel_nofault(str_field, str_val, STR_VAR_LEN_MAX); diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c index b87f41187c6a..9365ce407426 100644 --- a/kernel/trace/trace_events_user.c +++ b/kernel/trace/trace_events_user.c @@ -50,18 +50,6 @@ #define EVENT_STATUS_OTHER BIT(7) /* - * User register flags are not allowed yet, keep them here until we are - * ready to expose them out to the user ABI. - */ -enum user_reg_flag { - /* Event will not delete upon last reference closing */ - USER_EVENT_REG_PERSIST = 1U << 0, - - /* This value or above is currently non-ABI */ - USER_EVENT_REG_MAX = 1U << 1, -}; - -/* * Stores the system name, tables, and locks for a group of events. This * allows isolation for events by various means. */ @@ -220,6 +208,17 @@ static u32 user_event_key(char *name) return jhash(name, strlen(name), 0); } +static bool user_event_capable(u16 reg_flags) +{ + /* Persistent events require CAP_PERFMON / CAP_SYS_ADMIN */ + if (reg_flags & USER_EVENT_REG_PERSIST) { + if (!perfmon_capable()) + return false; + } + + return true; +} + static struct user_event *user_event_get(struct user_event *user) { refcount_inc(&user->refcnt); @@ -1811,6 +1810,9 @@ static int user_event_free(struct dyn_event *ev) if (!user_event_last_ref(user)) return -EBUSY; + if (!user_event_capable(user->reg_flags)) + return -EPERM; + return destroy_user_event(user); } @@ -1926,10 +1928,13 @@ static int user_event_parse(struct user_event_group *group, char *name, int argc = 0; char **argv; - /* User register flags are not ready yet */ - if (reg_flags != 0 || flags != NULL) + /* Currently don't support any text based flags */ + if (flags != NULL) return -EINVAL; + if (!user_event_capable(reg_flags)) + return -EPERM; + /* Prevent dyn_event from racing */ mutex_lock(&event_mutex); user = find_user_event(group, name, &key); @@ -2062,6 +2067,9 @@ static int delete_user_event(struct user_event_group *group, char *name) if (!user_event_last_ref(user)) return -EBUSY; + if (!user_event_capable(user->reg_flags)) + return -EPERM; + return destroy_user_event(user); } diff --git a/kernel/trace/trace_seq.c b/kernel/trace/trace_seq.c index bac06ee3b98b..7be97229ddf8 100644 --- a/kernel/trace/trace_seq.c +++ b/kernel/trace/trace_seq.c @@ -370,8 +370,12 @@ EXPORT_SYMBOL_GPL(trace_seq_path); */ int trace_seq_to_user(struct trace_seq *s, char __user *ubuf, int cnt) { + int ret; __trace_seq_init(s); - return seq_buf_to_user(&s->seq, ubuf, cnt); + ret = seq_buf_to_user(&s->seq, ubuf, s->readpos, cnt); + if (ret > 0) + s->readpos += ret; + return ret; } EXPORT_SYMBOL_GPL(trace_seq_to_user); diff --git a/lib/seq_buf.c b/lib/seq_buf.c index 45c450f423fa..010c730ca7fc 100644 --- a/lib/seq_buf.c +++ b/lib/seq_buf.c @@ -109,9 +109,7 @@ void seq_buf_do_printk(struct seq_buf *s, const char *lvl) if (s->size == 0 || s->len == 0) return; - seq_buf_terminate(s); - - start = s->buffer; + start = seq_buf_str(s); while ((lf = strchr(start, '\n'))) { int len = lf - start + 1; @@ -189,6 +187,7 @@ int seq_buf_puts(struct seq_buf *s, const char *str) seq_buf_set_overflow(s); return -1; } +EXPORT_SYMBOL_GPL(seq_buf_puts); /** * seq_buf_putc - sequence printing of simple character @@ -210,6 +209,7 @@ int seq_buf_putc(struct seq_buf *s, unsigned char c) seq_buf_set_overflow(s); return -1; } +EXPORT_SYMBOL_GPL(seq_buf_putc); /** * seq_buf_putmem - write raw data into the sequenc buffer @@ -324,23 +324,24 @@ int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc) * seq_buf_to_user - copy the sequence buffer to user space * @s: seq_buf descriptor * @ubuf: The userspace memory location to copy to + * @start: The first byte in the buffer to copy * @cnt: The amount to copy * * Copies the sequence buffer into the userspace memory pointed to - * by @ubuf. It starts from the last read position (@s->readpos) - * and writes up to @cnt characters or till it reaches the end of - * the content in the buffer (@s->len), which ever comes first. + * by @ubuf. It starts from @start and writes up to @cnt characters + * or until it reaches the end of the content in the buffer (@s->len), + * whichever comes first. * * On success, it returns a positive number of the number of bytes * it copied. * * On failure it returns -EBUSY if all of the content in the * sequence has been already read, which includes nothing in the - * sequence (@s->len == @s->readpos). + * sequence (@s->len == @start). * * Returns -EFAULT if the copy to userspace fails. */ -int seq_buf_to_user(struct seq_buf *s, char __user *ubuf, int cnt) +int seq_buf_to_user(struct seq_buf *s, char __user *ubuf, size_t start, int cnt) { int len; int ret; @@ -350,20 +351,17 @@ int seq_buf_to_user(struct seq_buf *s, char __user *ubuf, int cnt) len = seq_buf_used(s); - if (len <= s->readpos) + if (len <= start) return -EBUSY; - len -= s->readpos; + len -= start; if (cnt > len) cnt = len; - ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt); + ret = copy_to_user(ubuf, s->buffer + start, cnt); if (ret == cnt) return -EFAULT; - cnt -= ret; - - s->readpos += cnt; - return cnt; + return cnt - ret; } /** diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc index 21db6b720754..e21c9c27ece4 100644 --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc @@ -40,7 +40,9 @@ riscv*) esac : "Test get argument (1)" -if grep -q eventfs_add_dir available_filter_functions; then +if grep -q eventfs_create_dir available_filter_functions; then + DIR_NAME="eventfs_create_dir" +elif grep -q eventfs_add_dir available_filter_functions; then DIR_NAME="eventfs_add_dir" else DIR_NAME="tracefs_create_dir" diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc index 4e086f871cee..93217d459556 100644 --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc @@ -40,7 +40,9 @@ riscv*) esac : "Test get argument (1)" -if grep -q eventfs_add_dir available_filter_functions; then +if grep -q eventfs_create_dir available_filter_functions; then + DIR_NAME="eventfs_create_dir" +elif grep -q eventfs_add_dir available_filter_functions; then DIR_NAME="eventfs_add_dir" else DIR_NAME="tracefs_create_dir" diff --git a/tools/testing/selftests/user_events/abi_test.c b/tools/testing/selftests/user_events/abi_test.c index f5575ef2007c..cef1ff1af223 100644 --- a/tools/testing/selftests/user_events/abi_test.c +++ b/tools/testing/selftests/user_events/abi_test.c @@ -24,6 +24,18 @@ const char *data_file = "/sys/kernel/tracing/user_events_data"; const char *enable_file = "/sys/kernel/tracing/events/user_events/__abi_event/enable"; +static bool event_exists(void) +{ + int fd = open(enable_file, O_RDWR); + + if (fd < 0) + return false; + + close(fd); + + return true; +} + static int change_event(bool enable) { int fd = open(enable_file, O_RDWR); @@ -47,7 +59,22 @@ static int change_event(bool enable) return ret; } -static int reg_enable(void *enable, int size, int bit) +static int event_delete(void) +{ + int fd = open(data_file, O_RDWR); + int ret; + + if (fd < 0) + return -1; + + ret = ioctl(fd, DIAG_IOCSDEL, "__abi_event"); + + close(fd); + + return ret; +} + +static int reg_enable_flags(void *enable, int size, int bit, int flags) { struct user_reg reg = {0}; int fd = open(data_file, O_RDWR); @@ -58,6 +85,7 @@ static int reg_enable(void *enable, int size, int bit) reg.size = sizeof(reg); reg.name_args = (__u64)"__abi_event"; + reg.flags = flags; reg.enable_bit = bit; reg.enable_addr = (__u64)enable; reg.enable_size = size; @@ -69,6 +97,11 @@ static int reg_enable(void *enable, int size, int bit) return ret; } +static int reg_enable(void *enable, int size, int bit) +{ + return reg_enable_flags(enable, size, bit, 0); +} + static int reg_disable(void *enable, int bit) { struct user_unreg reg = {0}; @@ -128,6 +161,26 @@ TEST_F(user, enablement) { ASSERT_EQ(0, change_event(false)); } +TEST_F(user, flags) { + /* USER_EVENT_REG_PERSIST is allowed */ + ASSERT_EQ(0, reg_enable_flags(&self->check, sizeof(int), 0, + USER_EVENT_REG_PERSIST)); + ASSERT_EQ(0, reg_disable(&self->check, 0)); + + /* Ensure it exists after close and disable */ + ASSERT_TRUE(event_exists()); + + /* Ensure we can delete it */ + ASSERT_EQ(0, event_delete()); + + /* USER_EVENT_REG_MAX or above is not allowed */ + ASSERT_EQ(-1, reg_enable_flags(&self->check, sizeof(int), 0, + USER_EVENT_REG_MAX)); + + /* Ensure it does not exist after invalid flags */ + ASSERT_FALSE(event_exists()); +} + TEST_F(user, bit_sizes) { /* Allow 0-31 bits for 32-bit */ ASSERT_EQ(0, reg_enable(&self->check, sizeof(int), 0)); diff --git a/tools/testing/selftests/user_events/dyn_test.c b/tools/testing/selftests/user_events/dyn_test.c index a85980190bea..bdf9ab127488 100644 --- a/tools/testing/selftests/user_events/dyn_test.c +++ b/tools/testing/selftests/user_events/dyn_test.c @@ -17,9 +17,25 @@ #include "../kselftest_harness.h" #include "user_events_selftests.h" +const char *dyn_file = "/sys/kernel/tracing/dynamic_events"; const char *abi_file = "/sys/kernel/tracing/user_events_data"; const char *enable_file = "/sys/kernel/tracing/events/user_events/__test_event/enable"; +static int event_delete(void) +{ + int fd = open(abi_file, O_RDWR); + int ret; + + if (fd < 0) + return -1; + + ret = ioctl(fd, DIAG_IOCSDEL, "__test_event"); + + close(fd); + + return ret; +} + static bool wait_for_delete(void) { int i; @@ -64,7 +80,31 @@ static int unreg_event(int fd, int *check, int bit) return ioctl(fd, DIAG_IOCSUNREG, &unreg); } -static int parse(int *check, const char *value) +static int parse_dyn(const char *value) +{ + int fd = open(dyn_file, O_RDWR | O_APPEND); + int len = strlen(value); + int ret; + + if (fd == -1) + return -1; + + ret = write(fd, value, len); + + if (ret == len) + ret = 0; + else + ret = -1; + + close(fd); + + if (ret == 0) + event_delete(); + + return ret; +} + +static int parse_abi(int *check, const char *value) { int fd = open(abi_file, O_RDWR); int ret; @@ -90,6 +130,18 @@ static int parse(int *check, const char *value) return ret; } +static int parse(int *check, const char *value) +{ + int abi_ret = parse_abi(check, value); + int dyn_ret = parse_dyn(value); + + /* Ensure both ABI and DYN parse the same way */ + if (dyn_ret != abi_ret) + return -1; + + return dyn_ret; +} + static int check_match(int *check, const char *first, const char *second, bool *match) { int fd = open(abi_file, O_RDWR); |