diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 1d06c560c5e6..6fe5e8f7017c 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -3451,6 +3451,12 @@ static int tun_chr_fasync(int fd, struct file *file, int on) struct tun_file *tfile = file->private_data; int ret; + if (on) { + ret = file_f_owner_allocate(file); + if (ret) + goto out; + } + if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0) goto out; diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 407b0d87b7c1..7ae0c8934f42 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2225,6 +2225,12 @@ static int __tty_fasync(int fd, struct file *filp, int on) if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync")) goto out; + if (on) { + retval = file_f_owner_allocate(filp); + if (retval) + goto out; + } + retval = fasync_helper(fd, filp, on, &tty->fasync); if (retval <= 0) goto out; diff --git a/fs/fcntl.c b/fs/fcntl.c index 300e5d9ad913..0587a0e221a6 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -33,6 +33,8 @@ #include #include +#include "internal.h" + #define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME) static int setfl(int fd, struct file * filp, unsigned int arg) @@ -87,22 +89,64 @@ static int setfl(int fd, struct file * filp, unsigned int arg) return error; } +/* + * Allocate an file->f_owner struct if it doesn't exist, handling racing + * allocations correctly. + */ +int file_f_owner_allocate(struct file *file) +{ + struct fown_struct *f_owner; + + f_owner = file_f_owner(file); + if (f_owner) + return 0; + + f_owner = kzalloc(sizeof(struct fown_struct), GFP_KERNEL); + if (!f_owner) + return -ENOMEM; + + rwlock_init(&f_owner->lock); + f_owner->file = file; + /* If someone else raced us, drop our allocation. */ + if (unlikely(cmpxchg(&file->f_owner, NULL, f_owner))) + kfree(f_owner); + return 0; +} +EXPORT_SYMBOL(file_f_owner_allocate); + +void file_f_owner_release(struct file *file) +{ + struct fown_struct *f_owner; + + f_owner = file_f_owner(file); + if (f_owner) { + put_pid(f_owner->pid); + kfree(f_owner); + } +} + static void f_modown(struct file *filp, struct pid *pid, enum pid_type type, int force) { - write_lock_irq(&filp->f_owner.lock); - if (force || !filp->f_owner.pid) { - put_pid(filp->f_owner.pid); - filp->f_owner.pid = get_pid(pid); - filp->f_owner.pid_type = type; + struct fown_struct *f_owner; + + f_owner = file_f_owner(filp); + if (WARN_ON_ONCE(!f_owner)) + return; + + write_lock_irq(&f_owner->lock); + if (force || !f_owner->pid) { + put_pid(f_owner->pid); + f_owner->pid = get_pid(pid); + f_owner->pid_type = type; if (pid) { const struct cred *cred = current_cred(); - filp->f_owner.uid = cred->uid; - filp->f_owner.euid = cred->euid; + f_owner->uid = cred->uid; + f_owner->euid = cred->euid; } } - write_unlock_irq(&filp->f_owner.lock); + write_unlock_irq(&f_owner->lock); } void __f_setown(struct file *filp, struct pid *pid, enum pid_type type, @@ -119,6 +163,8 @@ int f_setown(struct file *filp, int who, int force) struct pid *pid = NULL; int ret = 0; + might_sleep(); + type = PIDTYPE_TGID; if (who < 0) { /* avoid overflow below */ @@ -129,6 +175,10 @@ int f_setown(struct file *filp, int who, int force) who = -who; } + ret = file_f_owner_allocate(filp); + if (ret) + return ret; + rcu_read_lock(); if (who) { pid = find_vpid(who); @@ -152,16 +202,21 @@ void f_delown(struct file *filp) pid_t f_getown(struct file *filp) { pid_t pid = 0; + struct fown_struct *f_owner; - read_lock_irq(&filp->f_owner.lock); + f_owner = file_f_owner(filp); + if (!f_owner) + return pid; + + read_lock_irq(&f_owner->lock); rcu_read_lock(); - if (pid_task(filp->f_owner.pid, filp->f_owner.pid_type)) { - pid = pid_vnr(filp->f_owner.pid); - if (filp->f_owner.pid_type == PIDTYPE_PGID) + if (pid_task(f_owner->pid, f_owner->pid_type)) { + pid = pid_vnr(f_owner->pid); + if (f_owner->pid_type == PIDTYPE_PGID) pid = -pid; } rcu_read_unlock(); - read_unlock_irq(&filp->f_owner.lock); + read_unlock_irq(&f_owner->lock); return pid; } @@ -194,6 +249,10 @@ static int f_setown_ex(struct file *filp, unsigned long arg) return -EINVAL; } + ret = file_f_owner_allocate(filp); + if (ret) + return ret; + rcu_read_lock(); pid = find_vpid(owner.pid); if (owner.pid && !pid) @@ -210,13 +269,20 @@ static int f_getown_ex(struct file *filp, unsigned long arg) struct f_owner_ex __user *owner_p = (void __user *)arg; struct f_owner_ex owner = {}; int ret = 0; + struct fown_struct *f_owner; + enum pid_type pid_type = PIDTYPE_PID; - read_lock_irq(&filp->f_owner.lock); - rcu_read_lock(); - if (pid_task(filp->f_owner.pid, filp->f_owner.pid_type)) - owner.pid = pid_vnr(filp->f_owner.pid); - rcu_read_unlock(); - switch (filp->f_owner.pid_type) { + f_owner = file_f_owner(filp); + if (f_owner) { + read_lock_irq(&f_owner->lock); + rcu_read_lock(); + if (pid_task(f_owner->pid, f_owner->pid_type)) + owner.pid = pid_vnr(f_owner->pid); + rcu_read_unlock(); + pid_type = f_owner->pid_type; + } + + switch (pid_type) { case PIDTYPE_PID: owner.type = F_OWNER_TID; break; @@ -234,7 +300,8 @@ static int f_getown_ex(struct file *filp, unsigned long arg) ret = -EINVAL; break; } - read_unlock_irq(&filp->f_owner.lock); + if (f_owner) + read_unlock_irq(&f_owner->lock); if (!ret) { ret = copy_to_user(owner_p, &owner, sizeof(owner)); @@ -248,14 +315,18 @@ static int f_getown_ex(struct file *filp, unsigned long arg) static int f_getowner_uids(struct file *filp, unsigned long arg) { struct user_namespace *user_ns = current_user_ns(); + struct fown_struct *f_owner; uid_t __user *dst = (void __user *)arg; - uid_t src[2]; + uid_t src[2] = {0, 0}; int err; - read_lock_irq(&filp->f_owner.lock); - src[0] = from_kuid(user_ns, filp->f_owner.uid); - src[1] = from_kuid(user_ns, filp->f_owner.euid); - read_unlock_irq(&filp->f_owner.lock); + f_owner = file_f_owner(filp); + if (f_owner) { + read_lock_irq(&f_owner->lock); + src[0] = from_kuid(user_ns, f_owner->uid); + src[1] = from_kuid(user_ns, f_owner->euid); + read_unlock_irq(&f_owner->lock); + } err = put_user(src[0], &dst[0]); err |= put_user(src[1], &dst[1]); @@ -343,6 +414,30 @@ static long f_dupfd_query(int fd, struct file *filp) return f.file == filp; } +static int f_owner_sig(struct file *filp, int signum, bool setsig) +{ + int ret = 0; + struct fown_struct *f_owner; + + might_sleep(); + + if (setsig) { + if (!valid_signal(signum)) + return -EINVAL; + + ret = file_f_owner_allocate(filp); + if (ret) + return ret; + } + + f_owner = file_f_owner(filp); + if (setsig) + f_owner->signum = signum; + else if (f_owner) + ret = f_owner->signum; + return ret; +} + static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, struct file *filp) { @@ -421,15 +516,10 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, err = f_getowner_uids(filp, arg); break; case F_GETSIG: - err = filp->f_owner.signum; + err = f_owner_sig(filp, 0, false); break; case F_SETSIG: - /* arg == 0 restores default behaviour. */ - if (!valid_signal(argi)) { - break; - } - err = 0; - filp->f_owner.signum = argi; + err = f_owner_sig(filp, argi, true); break; case F_GETLEASE: err = fcntl_getlease(filp); @@ -844,14 +934,19 @@ static void send_sigurg_to_task(struct task_struct *p, do_send_sig_info(SIGURG, SEND_SIG_PRIV, p, type); } -int send_sigurg(struct fown_struct *fown) +int send_sigurg(struct file *file) { + struct fown_struct *fown; struct task_struct *p; enum pid_type type; struct pid *pid; unsigned long flags; int ret = 0; + fown = file_f_owner(file); + if (!fown) + return 0; + read_lock_irqsave(&fown->lock, flags); type = fown->pid_type; @@ -1027,13 +1122,16 @@ static void kill_fasync_rcu(struct fasync_struct *fa, int sig, int band) } read_lock_irqsave(&fa->fa_lock, flags); if (fa->fa_file) { - fown = &fa->fa_file->f_owner; + fown = file_f_owner(fa->fa_file); + if (!fown) + goto next; /* Don't send SIGURG to processes which have not set a queued signum: SIGURG has its own default signalling mechanism. */ if (!(sig == SIGURG && fown->signum == 0)) send_sigio(fown, fa->fa_fd, band); } +next: read_unlock_irqrestore(&fa->fa_lock, flags); fa = rcu_dereference(fa->fa_next); } diff --git a/fs/file_table.c b/fs/file_table.c index ca7843dde56d..861c03608e83 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -155,7 +155,6 @@ static int init_file(struct file *f, int flags, const struct cred *cred) return error; } - rwlock_init(&f->f_owner.lock); spin_lock_init(&f->f_lock); mutex_init(&f->f_pos_lock); f->f_flags = flags; @@ -425,7 +424,7 @@ static void __fput(struct file *file) cdev_put(inode->i_cdev); } fops_put(file->f_op); - put_pid(file->f_owner.pid); + file_f_owner_release(file); put_file_access(file); dput(dentry); if (unlikely(mode & FMODE_NEED_UNMOUNT)) @@ -512,9 +511,14 @@ EXPORT_SYMBOL(__fput_sync); void __init files_init(void) { - filp_cachep = kmem_cache_create("filp", sizeof(struct file), 0, - SLAB_TYPESAFE_BY_RCU | SLAB_HWCACHE_ALIGN | - SLAB_PANIC | SLAB_ACCOUNT, NULL); + struct kmem_cache_args args = { + .use_freeptr_offset = true, + .freeptr_offset = offsetof(struct file, f_freeptr), + }; + + filp_cachep = kmem_cache_create("filp", sizeof(struct file), &args, + SLAB_HWCACHE_ALIGN | SLAB_PANIC | + SLAB_ACCOUNT | SLAB_TYPESAFE_BY_RCU); percpu_counter_init(&nr_files, 0, GFP_KERNEL); } diff --git a/fs/internal.h b/fs/internal.h index cdd73209eecb..8c1b7acbbe8f 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -337,3 +337,4 @@ static inline bool path_mounted(const struct path *path) { return path->mnt->mnt_root == path->dentry; } +void file_f_owner_release(struct file *file); diff --git a/fs/locks.c b/fs/locks.c index e45cad40f8b6..b51b1c395ce6 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -1451,7 +1451,7 @@ int lease_modify(struct file_lease *fl, int arg, struct list_head *dispose) struct file *filp = fl->c.flc_file; f_delown(filp); - filp->f_owner.signum = 0; + file_f_owner(filp)->signum = 0; fasync_helper(0, fl->c.flc_file, 0, &fl->fl_fasync); if (fl->fl_fasync != NULL) { printk(KERN_ERR "locks_delete_lock: fasync == %p\n", fl->fl_fasync); @@ -1783,6 +1783,10 @@ generic_add_lease(struct file *filp, int arg, struct file_lease **flp, void **pr lease = *flp; trace_generic_add_lease(inode, lease); + error = file_f_owner_allocate(filp); + if (error) + return error; + /* Note that arg is never F_UNLCK here */ ctx = locks_get_lock_context(inode, arg); if (!ctx) diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c index f3669403fabf..46440fbb8662 100644 --- a/fs/notify/dnotify/dnotify.c +++ b/fs/notify/dnotify/dnotify.c @@ -110,7 +110,7 @@ static int dnotify_handle_event(struct fsnotify_mark *inode_mark, u32 mask, prev = &dn->dn_next; continue; } - fown = &dn->dn_filp->f_owner; + fown = file_f_owner(dn->dn_filp); send_sigio(fown, dn->dn_fd, POLL_MSG); if (dn->dn_mask & FS_DN_MULTISHOT) prev = &dn->dn_next; @@ -316,6 +316,10 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned int arg) goto out_err; } + error = file_f_owner_allocate(filp); + if (error) + goto out_err; + /* set up the new_fsn_mark and new_dn_mark */ new_fsn_mark = &new_dn_mark->fsn_mark; fsnotify_init_mark(new_fsn_mark, dnotify_group); diff --git a/include/linux/fs.h b/include/linux/fs.h index fb0426f349fc..58c91a52cad1 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -947,6 +947,7 @@ static inline unsigned imajor(const struct inode *inode) } struct fown_struct { + struct file *file; /* backpointer for security modules */ rwlock_t lock; /* protects pid, uid, euid fields */ struct pid *pid; /* pid or -pgrp where SIGIO should be sent */ enum pid_type pid_type; /* Kind of process group SIGIO should be sent to */ @@ -986,52 +987,65 @@ static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index) index < ra->start + ra->size); } -/* - * f_{lock,count,pos_lock} members can be highly contended and share - * the same cacheline. f_{lock,mode} are very frequently used together - * and so share the same cacheline as well. The read-mostly - * f_{path,inode,op} are kept on a separate cacheline. +/** + * struct file - Represents a file + * @f_count: reference count + * @f_lock: Protects f_ep, f_flags. Must not be taken from IRQ context. + * @f_mode: FMODE_* flags often used in hotpaths + * @f_op: file operations + * @f_mapping: Contents of a cacheable, mappable object. + * @private_data: filesystem or driver specific data + * @f_inode: cached inode + * @f_flags: file flags + * @f_iocb_flags: iocb flags + * @f_cred: stashed credentials of creator/opener + * @f_path: path of the file + * @f_pos_lock: lock protecting file position + * @f_pos: file position + * @f_version: file version + * @f_security: LSM security context of this file + * @f_owner: file owner + * @f_wb_err: writeback error + * @f_sb_err: per sb writeback errors + * @f_ep: link of all epoll hooks for this file + * @f_task_work: task work entry point + * @f_llist: work queue entrypoint + * @f_ra: file's readahead state + * @f_freeptr: Pointer used by SLAB_TYPESAFE_BY_RCU file cache (don't touch.) */ struct file { - union { - /* fput() uses task work when closing and freeing file (default). */ - struct callback_head f_task_work; - /* fput() must use workqueue (most kernel threads). */ - struct llist_node f_llist; - unsigned int f_iocb_flags; - }; - - /* - * Protects f_ep, f_flags. - * Must not be taken from IRQ context. - */ - spinlock_t f_lock; - fmode_t f_mode; - atomic_long_t f_count; - struct mutex f_pos_lock; - loff_t f_pos; - unsigned int f_flags; - struct fown_struct f_owner; - const struct cred *f_cred; - struct file_ra_state f_ra; - struct path f_path; - struct inode *f_inode; /* cached value */ + atomic_long_t f_count; + spinlock_t f_lock; + fmode_t f_mode; const struct file_operations *f_op; - - u64 f_version; + struct address_space *f_mapping; + void *private_data; + struct inode *f_inode; + unsigned int f_flags; + unsigned int f_iocb_flags; + const struct cred *f_cred; + /* --- cacheline 1 boundary (64 bytes) --- */ + struct path f_path; + struct mutex f_pos_lock; + loff_t f_pos; + u64 f_version; + /* --- cacheline 2 boundary (128 bytes) --- */ #ifdef CONFIG_SECURITY - void *f_security; + void *f_security; #endif - /* needed for tty driver, and maybe others */ - void *private_data; - + struct fown_struct *f_owner; + errseq_t f_wb_err; + errseq_t f_sb_err; #ifdef CONFIG_EPOLL - /* Used by fs/eventpoll.c to link all the hooks to this file */ - struct hlist_head *f_ep; -#endif /* #ifdef CONFIG_EPOLL */ - struct address_space *f_mapping; - errseq_t f_wb_err; - errseq_t f_sb_err; /* for syncfs */ + struct hlist_head *f_ep; +#endif + union { + struct callback_head f_task_work; + struct llist_node f_llist; + struct file_ra_state f_ra; + freeptr_t f_freeptr; + }; + /* --- cacheline 3 boundary (192 bytes) --- */ } __randomize_layout __attribute__((aligned(4))); /* lest something weird decides that 2 is OK */ @@ -1076,6 +1090,12 @@ struct file_lease; #define OFFT_OFFSET_MAX type_max(off_t) #endif +int file_f_owner_allocate(struct file *file); +static inline struct fown_struct *file_f_owner(const struct file *file) +{ + return READ_ONCE(file->f_owner); +} + extern void send_sigio(struct fown_struct *fown, int fd, int band); static inline struct inode *file_inode(const struct file *f) @@ -1124,7 +1144,7 @@ extern void __f_setown(struct file *filp, struct pid *, enum pid_type, int force extern int f_setown(struct file *filp, int who, int force); extern void f_delown(struct file *filp); extern pid_t f_getown(struct file *filp); -extern int send_sigurg(struct fown_struct *fown); +extern int send_sigurg(struct file *file); /* * sb->s_flags. Note that these mirror the equivalent MS_* flags where diff --git a/include/linux/slab.h b/include/linux/slab.h index 3be2a5ed4936..da3a546571e7 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -212,6 +212,12 @@ enum _slab_flag_bits { #define SLAB_NO_OBJ_EXT __SLAB_FLAG_UNUSED #endif +/* + * freeptr_t represents a SLUB freelist pointer, which might be encoded + * and not dereferenceable if CONFIG_SLAB_FREELIST_HARDENED is enabled. + */ +typedef struct { unsigned long v; } freeptr_t; + /* * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests. * @@ -234,14 +240,173 @@ struct mem_cgroup; */ bool slab_is_available(void); -struct kmem_cache *kmem_cache_create(const char *name, unsigned int size, - unsigned int align, slab_flags_t flags, - void (*ctor)(void *)); -struct kmem_cache *kmem_cache_create_usercopy(const char *name, - unsigned int size, unsigned int align, - slab_flags_t flags, - unsigned int useroffset, unsigned int usersize, - void (*ctor)(void *)); +/** + * struct kmem_cache_args - Less common arguments for kmem_cache_create() + * + * Any uninitialized fields of the structure are interpreted as unused. The + * exception is @freeptr_offset where %0 is a valid value, so + * @use_freeptr_offset must be also set to %true in order to interpret the field + * as used. For @useroffset %0 is also valid, but only with non-%0 + * @usersize. + * + * When %NULL args is passed to kmem_cache_create(), it is equivalent to all + * fields unused. + */ +struct kmem_cache_args { + /** + * @align: The required alignment for the objects. + * + * %0 means no specific alignment is requested. + */ + unsigned int align; + /** + * @useroffset: Usercopy region offset. + * + * %0 is a valid offset, when @usersize is non-%0 + */ + unsigned int useroffset; + /** + * @usersize: Usercopy region size. + * + * %0 means no usercopy region is specified. + */ + unsigned int usersize; + /** + * @freeptr_offset: Custom offset for the free pointer + * in &SLAB_TYPESAFE_BY_RCU caches + * + * By default &SLAB_TYPESAFE_BY_RCU caches place the free pointer + * outside of the object. This might cause the object to grow in size. + * Cache creators that have a reason to avoid this can specify a custom + * free pointer offset in their struct where the free pointer will be + * placed. + * + * Note that placing the free pointer inside the object requires the + * caller to ensure that no fields are invalidated that are required to + * guard against object recycling (See &SLAB_TYPESAFE_BY_RCU for + * details). + * + * Using %0 as a value for @freeptr_offset is valid. If @freeptr_offset + * is specified, %use_freeptr_offset must be set %true. + * + * Note that @ctor currently isn't supported with custom free pointers + * as a @ctor requires an external free pointer. + */ + unsigned int freeptr_offset; + /** + * @use_freeptr_offset: Whether a @freeptr_offset is used. + */ + bool use_freeptr_offset; + /** + * @ctor: A constructor for the objects. + * + * The constructor is invoked for each object in a newly allocated slab + * page. It is the cache user's responsibility to free object in the + * same state as after calling the constructor, or deal appropriately + * with any differences between a freshly constructed and a reallocated + * object. + * + * %NULL means no constructor. + */ + void (*ctor)(void *); +}; + +struct kmem_cache *__kmem_cache_create_args(const char *name, + unsigned int object_size, + struct kmem_cache_args *args, + slab_flags_t flags); +static inline struct kmem_cache * +__kmem_cache_create(const char *name, unsigned int size, unsigned int align, + slab_flags_t flags, void (*ctor)(void *)) +{ + struct kmem_cache_args kmem_args = { + .align = align, + .ctor = ctor, + }; + + return __kmem_cache_create_args(name, size, &kmem_args, flags); +} + +/** + * kmem_cache_create_usercopy - Create a kmem cache with a region suitable + * for copying to userspace. + * @name: A string which is used in /proc/slabinfo to identify this cache. + * @size: The size of objects to be created in this cache. + * @align: The required alignment for the objects. + * @flags: SLAB flags + * @useroffset: Usercopy region offset + * @usersize: Usercopy region size + * @ctor: A constructor for the objects, or %NULL. + * + * This is a legacy wrapper, new code should use either KMEM_CACHE_USERCOPY() + * if whitelisting a single field is sufficient, or kmem_cache_create() with + * the necessary parameters passed via the args parameter (see + * &struct kmem_cache_args) + * + * Return: a pointer to the cache on success, NULL on failure. + */ +static inline struct kmem_cache * +kmem_cache_create_usercopy(const char *name, unsigned int size, + unsigned int align, slab_flags_t flags, + unsigned int useroffset, unsigned int usersize, + void (*ctor)(void *)) +{ + struct kmem_cache_args kmem_args = { + .align = align, + .ctor = ctor, + .useroffset = useroffset, + .usersize = usersize, + }; + + return __kmem_cache_create_args(name, size, &kmem_args, flags); +} + +/* If NULL is passed for @args, use this variant with default arguments. */ +static inline struct kmem_cache * +__kmem_cache_default_args(const char *name, unsigned int size, + struct kmem_cache_args *args, + slab_flags_t flags) +{ + struct kmem_cache_args kmem_default_args = {}; + + /* Make sure we don't get passed garbage. */ + if (WARN_ON_ONCE(args)) + return ERR_PTR(-EINVAL); + + return __kmem_cache_create_args(name, size, &kmem_default_args, flags); +} + +/** + * kmem_cache_create - Create a kmem cache. + * @__name: A string which is used in /proc/slabinfo to identify this cache. + * @__object_size: The size of objects to be created in this cache. + * @__args: Optional arguments, see &struct kmem_cache_args. Passing %NULL + * means defaults will be used for all the arguments. + * + * This is currently implemented as a macro using ``_Generic()`` to call + * either the new variant of the function, or a legacy one. + * + * The new variant has 4 parameters: + * ``kmem_cache_create(name, object_size, args, flags)`` + * + * See __kmem_cache_create_args() which implements this. + * + * The legacy variant has 5 parameters: + * ``kmem_cache_create(name, object_size, align, flags, ctor)`` + * + * The align and ctor parameters map to the respective fields of + * &struct kmem_cache_args + * + * Context: Cannot be called within a interrupt, but can be interrupted. + * + * Return: a pointer to the cache on success, NULL on failure. + */ +#define kmem_cache_create(__name, __object_size, __args, ...) \ + _Generic((__args), \ + struct kmem_cache_args *: __kmem_cache_create_args, \ + void *: __kmem_cache_default_args, \ + default: __kmem_cache_create)(__name, __object_size, __args, __VA_ARGS__) + void kmem_cache_destroy(struct kmem_cache *s); int kmem_cache_shrink(struct kmem_cache *s); @@ -253,20 +418,23 @@ int kmem_cache_shrink(struct kmem_cache *s); * f.e. add ____cacheline_aligned_in_smp to the struct declaration * then the objects will be properly aligned in SMP configurations. */ -#define KMEM_CACHE(__struct, __flags) \ - kmem_cache_create(#__struct, sizeof(struct __struct), \ - __alignof__(struct __struct), (__flags), NULL) +#define KMEM_CACHE(__struct, __flags) \ + __kmem_cache_create_args(#__struct, sizeof(struct __struct), \ + &(struct kmem_cache_args) { \ + .align = __alignof__(struct __struct), \ + }, (__flags)) /* * To whitelist a single field for copying to/from usercopy, use this * macro instead for KMEM_CACHE() above. */ -#define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \ - kmem_cache_create_usercopy(#__struct, \ - sizeof(struct __struct), \ - __alignof__(struct __struct), (__flags), \ - offsetof(struct __struct, __field), \ - sizeof_field(struct __struct, __field), NULL) +#define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \ + __kmem_cache_create_args(#__struct, sizeof(struct __struct), \ + &(struct kmem_cache_args) { \ + .align = __alignof__(struct __struct), \ + .useroffset = offsetof(struct __struct, __field), \ + .usersize = sizeof_field(struct __struct, __field), \ + }, (__flags)) /* * Common kmalloc functions provided by all allocators diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 3942db160f18..d9d721d1424e 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -3638,6 +3638,11 @@ SYSCALL_DEFINE2(io_uring_setup, u32, entries, static int __init io_uring_init(void) { + struct kmem_cache_args kmem_args = { + .useroffset = offsetof(struct io_kiocb, cmd.data), + .usersize = sizeof_field(struct io_kiocb, cmd.data), + }; + #define __BUILD_BUG_VERIFY_OFFSET_SIZE(stype, eoffset, esize, ename) do { \ BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \ BUILD_BUG_ON(sizeof_field(stype, ename) != esize); \ @@ -3722,12 +3727,9 @@ static int __init io_uring_init(void) * range, and HARDENED_USERCOPY will complain if we haven't * correctly annotated this range. */ - req_cachep = kmem_cache_create_usercopy("io_kiocb", - sizeof(struct io_kiocb), 0, - SLAB_HWCACHE_ALIGN | SLAB_PANIC | - SLAB_ACCOUNT | SLAB_TYPESAFE_BY_RCU, - offsetof(struct io_kiocb, cmd.data), - sizeof_field(struct io_kiocb, cmd.data), NULL); + req_cachep = kmem_cache_create("io_kiocb", sizeof(struct io_kiocb), &kmem_args, + SLAB_HWCACHE_ALIGN | SLAB_PANIC | SLAB_ACCOUNT | + SLAB_TYPESAFE_BY_RCU); io_buf_cachep = KMEM_CACHE(io_buffer, SLAB_HWCACHE_ALIGN | SLAB_PANIC | SLAB_ACCOUNT); diff --git a/mm/slab.h b/mm/slab.h index 9f907e930609..f22fb760b286 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -422,7 +422,9 @@ kmalloc_slab(size_t size, kmem_buckets *b, gfp_t flags, unsigned long caller) gfp_t kmalloc_fix_flags(gfp_t flags); /* Functions provided by the slab allocators */ -int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags); +int do_kmem_cache_create(struct kmem_cache *s, const char *name, + unsigned int size, struct kmem_cache_args *args, + slab_flags_t flags); void __init kmem_cache_init(void); extern void create_boot_cache(struct kmem_cache *, const char *name, diff --git a/mm/slab_common.c b/mm/slab_common.c index 11ef221bce17..61f32420230a 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -215,32 +215,29 @@ struct kmem_cache *find_mergeable(unsigned int size, unsigned int align, } static struct kmem_cache *create_cache(const char *name, - unsigned int object_size, unsigned int align, - slab_flags_t flags, unsigned int useroffset, - unsigned int usersize, void (*ctor)(void *), - struct kmem_cache *root_cache) + unsigned int object_size, + struct kmem_cache_args *args, + slab_flags_t flags) { struct kmem_cache *s; int err; - if (WARN_ON(useroffset + usersize > object_size)) - useroffset = usersize = 0; + if (WARN_ON(args->useroffset + args->usersize > object_size)) + args->useroffset = args->usersize = 0; + + /* If a custom freelist pointer is requested make sure it's sane. */ + err = -EINVAL; + if (args->use_freeptr_offset && + (args->freeptr_offset >= object_size || + !(flags & SLAB_TYPESAFE_BY_RCU) || + !IS_ALIGNED(args->freeptr_offset, sizeof(freeptr_t)))) + goto out; err = -ENOMEM; s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL); if (!s) goto out; - - s->name = name; - s->size = s->object_size = object_size; - s->align = align; - s->ctor = ctor; -#ifdef CONFIG_HARDENED_USERCOPY - s->useroffset = useroffset; - s->usersize = usersize; -#endif - - err = __kmem_cache_create(s, flags); + err = do_kmem_cache_create(s, name, object_size, args, flags); if (err) goto out_free_cache; @@ -255,39 +252,24 @@ out: } /** - * kmem_cache_create_usercopy - Create a cache with a region suitable - * for copying to userspace + * __kmem_cache_create_args - Create a kmem cache. * @name: A string which is used in /proc/slabinfo to identify this cache. - * @size: The size of objects to be created in this cache. - * @align: The required alignment for the objects. - * @flags: SLAB flags - * @useroffset: Usercopy region offset - * @usersize: Usercopy region size - * @ctor: A constructor for the objects. + * @object_size: The size of objects to be created in this cache. + * @args: Additional arguments for the cache creation (see + * &struct kmem_cache_args). + * @flags: See %SLAB_* flags for an explanation of individual @flags. * - * Cannot be called within a interrupt, but can be interrupted. - * The @ctor is run when new pages are allocated by the cache. + * Not to be called directly, use the kmem_cache_create() wrapper with the same + * parameters. * - * The flags are - * - * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) - * to catch references to uninitialised memory. - * - * %SLAB_RED_ZONE - Insert `Red` zones around the allocated memory to check - * for buffer overruns. - * - * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware - * cacheline. This can be beneficial if you're counting cycles as closely - * as davem. + * Context: Cannot be called within a interrupt, but can be interrupted. * * Return: a pointer to the cache on success, NULL on failure. */ -struct kmem_cache * -kmem_cache_create_usercopy(const char *name, - unsigned int size, unsigned int align, - slab_flags_t flags, - unsigned int useroffset, unsigned int usersize, - void (*ctor)(void *)) +struct kmem_cache *__kmem_cache_create_args(const char *name, + unsigned int object_size, + struct kmem_cache_args *args, + slab_flags_t flags) { struct kmem_cache *s = NULL; const char *cache_name; @@ -309,7 +291,7 @@ kmem_cache_create_usercopy(const char *name, mutex_lock(&slab_mutex); - err = kmem_cache_sanity_check(name, size); + err = kmem_cache_sanity_check(name, object_size); if (err) { goto out_unlock; } @@ -330,12 +312,14 @@ kmem_cache_create_usercopy(const char *name, /* Fail closed on bad usersize of useroffset values. */ if (!IS_ENABLED(CONFIG_HARDENED_USERCOPY) || - WARN_ON(!usersize && useroffset) || - WARN_ON(size < usersize || size - usersize < useroffset)) - usersize = useroffset = 0; + WARN_ON(!args->usersize && args->useroffset) || + WARN_ON(object_size < args->usersize || + object_size - args->usersize < args->useroffset)) + args->usersize = args->useroffset = 0; - if (!usersize) - s = __kmem_cache_alias(name, size, align, flags, ctor); + if (!args->usersize) + s = __kmem_cache_alias(name, object_size, args->align, flags, + args->ctor); if (s) goto out_unlock; @@ -345,9 +329,8 @@ kmem_cache_create_usercopy(const char *name, goto out_unlock; } - s = create_cache(cache_name, size, - calculate_alignment(flags, align, size), - flags, useroffset, usersize, ctor, NULL); + args->align = calculate_alignment(flags, args->align, object_size); + s = create_cache(cache_name, object_size, args, flags); if (IS_ERR(s)) { err = PTR_ERR(s); kfree_const(cache_name); @@ -369,41 +352,7 @@ out_unlock: } return s; } -EXPORT_SYMBOL(kmem_cache_create_usercopy); - -/** - * kmem_cache_create - Create a cache. - * @name: A string which is used in /proc/slabinfo to identify this cache. - * @size: The size of objects to be created in this cache. - * @align: The required alignment for the objects. - * @flags: SLAB flags - * @ctor: A constructor for the objects. - * - * Cannot be called within a interrupt, but can be interrupted. - * The @ctor is run when new pages are allocated by the cache. - * - * The flags are - * - * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) - * to catch references to uninitialised memory. - * - * %SLAB_RED_ZONE - Insert `Red` zones around the allocated memory to check - * for buffer overruns. - * - * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware - * cacheline. This can be beneficial if you're counting cycles as closely - * as davem. - * - * Return: a pointer to the cache on success, NULL on failure. - */ -struct kmem_cache * -kmem_cache_create(const char *name, unsigned int size, unsigned int align, - slab_flags_t flags, void (*ctor)(void *)) -{ - return kmem_cache_create_usercopy(name, size, align, flags, 0, 0, - ctor); -} -EXPORT_SYMBOL(kmem_cache_create); +EXPORT_SYMBOL(__kmem_cache_create_args); static struct kmem_cache *kmem_buckets_cache __ro_after_init; @@ -689,9 +638,7 @@ void __init create_boot_cache(struct kmem_cache *s, const char *name, { int err; unsigned int align = ARCH_KMALLOC_MINALIGN; - - s->name = name; - s->size = s->object_size = size; + struct kmem_cache_args kmem_args = {}; /* * kmalloc caches guarantee alignment of at least the largest @@ -700,14 +647,14 @@ void __init create_boot_cache(struct kmem_cache *s, const char *name, */ if (flags & SLAB_KMALLOC) align = max(align, 1U << (ffs(size) - 1)); - s->align = calculate_alignment(flags, align, size); + kmem_args.align = calculate_alignment(flags, align, size); #ifdef CONFIG_HARDENED_USERCOPY - s->useroffset = useroffset; - s->usersize = usersize; + kmem_args.useroffset = useroffset; + kmem_args.usersize = usersize; #endif - err = __kmem_cache_create(s, flags); + err = do_kmem_cache_create(s, name, size, &kmem_args, flags); if (err) panic("Creation of kmalloc slab %s size=%u failed. Reason %d\n", diff --git a/mm/slub.c b/mm/slub.c index 81cea762d094..3d454888e921 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -465,12 +465,6 @@ static struct workqueue_struct *flushwq; * Core slab cache functions *******************************************************************/ -/* - * freeptr_t represents a SLUB freelist pointer, which might be encoded - * and not dereferenceable if CONFIG_SLAB_FREELIST_HARDENED is enabled. - */ -typedef struct { unsigned long v; } freeptr_t; - /* * Returns freelist pointer (ptr). With hardening, this is obfuscated * with an XOR of the address where the pointer is held and a per-cache @@ -4019,6 +4013,8 @@ static void *__slab_alloc_node(struct kmem_cache *s, /* * If the object has been wiped upon free, make sure it's fully initialized by * zeroing out freelist pointer. + * + * Note that we also wipe custom freelist pointers. */ static __always_inline void maybe_wipe_obj_freeptr(struct kmem_cache *s, void *obj) @@ -5282,7 +5278,7 @@ static void set_cpu_partial(struct kmem_cache *s) * calculate_sizes() determines the order and the distribution of data within * a slab object. */ -static int calculate_sizes(struct kmem_cache *s) +static int calculate_sizes(struct kmem_cache_args *args, struct kmem_cache *s) { slab_flags_t flags = s->flags; unsigned int size = s->object_size; @@ -5323,7 +5319,8 @@ static int calculate_sizes(struct kmem_cache *s) */ s->inuse = size; - if ((flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)) || s->ctor || + if (((flags & SLAB_TYPESAFE_BY_RCU) && !args->use_freeptr_offset) || + (flags & SLAB_POISON) || s->ctor || ((flags & SLAB_RED_ZONE) && (s->object_size < sizeof(void *) || slub_debug_orig_size(s)))) { /* @@ -5344,6 +5341,8 @@ static int calculate_sizes(struct kmem_cache *s) */ s->offset = size; size += sizeof(void *); + } else if ((flags & SLAB_TYPESAFE_BY_RCU) && args->use_freeptr_offset) { + s->offset = args->freeptr_offset; } else { /* * Store freelist pointer near middle of object to keep @@ -5418,65 +5417,6 @@ static int calculate_sizes(struct kmem_cache *s) return !!oo_objects(s->oo); } -static int kmem_cache_open(struct kmem_cache *s, slab_flags_t flags) -{ - s->flags = kmem_cache_flags(flags, s->name); -#ifdef CONFIG_SLAB_FREELIST_HARDENED - s->random = get_random_long(); -#endif - - if (!calculate_sizes(s)) - goto error; - if (disable_higher_order_debug) { - /* - * Disable debugging flags that store metadata if the min slab - * order increased. - */ - if (get_order(s->size) > get_order(s->object_size)) { - s->flags &= ~DEBUG_METADATA_FLAGS; - s->offset = 0; - if (!calculate_sizes(s)) - goto error; - } - } - -#ifdef system_has_freelist_aba - if (system_has_freelist_aba() && !(s->flags & SLAB_NO_CMPXCHG)) { - /* Enable fast mode */ - s->flags |= __CMPXCHG_DOUBLE; - } -#endif - - /* - * The larger the object size is, the more slabs we want on the partial - * list to avoid pounding the page allocator excessively. - */ - s->min_partial = min_t(unsigned long, MAX_PARTIAL, ilog2(s->size) / 2); - s->min_partial = max_t(unsigned long, MIN_PARTIAL, s->min_partial); - - set_cpu_partial(s); - -#ifdef CONFIG_NUMA - s->remote_node_defrag_ratio = 1000; -#endif - - /* Initialize the pre-computed randomized freelist if slab is up */ - if (slab_state >= UP) { - if (init_cache_random_seq(s)) - goto error; - } - - if (!init_kmem_cache_nodes(s)) - goto error; - - if (alloc_kmem_cache_cpus(s)) - return 0; - -error: - __kmem_cache_release(s); - return -EINVAL; -} - static void list_slab_objects(struct kmem_cache *s, struct slab *slab, const char *text) { @@ -6030,28 +5970,90 @@ __kmem_cache_alias(const char *name, unsigned int size, unsigned int align, return s; } -int __kmem_cache_create(struct kmem_cache *s, slab_flags_t flags) +int do_kmem_cache_create(struct kmem_cache *s, const char *name, + unsigned int size, struct kmem_cache_args *args, + slab_flags_t flags) { - int err; + int err = -EINVAL; - err = kmem_cache_open(s, flags); - if (err) - return err; + s->name = name; + s->size = s->object_size = size; + + s->flags = kmem_cache_flags(flags, s->name); +#ifdef CONFIG_SLAB_FREELIST_HARDENED + s->random = get_random_long(); +#endif + s->align = args->align; + s->ctor = args->ctor; +#ifdef CONFIG_HARDENED_USERCOPY + s->useroffset = args->useroffset; + s->usersize = args->usersize; +#endif + + if (!calculate_sizes(args, s)) + goto out; + if (disable_higher_order_debug) { + /* + * Disable debugging flags that store metadata if the min slab + * order increased. + */ + if (get_order(s->size) > get_order(s->object_size)) { + s->flags &= ~DEBUG_METADATA_FLAGS; + s->offset = 0; + if (!calculate_sizes(args, s)) + goto out; + } + } + +#ifdef system_has_freelist_aba + if (system_has_freelist_aba() && !(s->flags & SLAB_NO_CMPXCHG)) { + /* Enable fast mode */ + s->flags |= __CMPXCHG_DOUBLE; + } +#endif + + /* + * The larger the object size is, the more slabs we want on the partial + * list to avoid pounding the page allocator excessively. + */ + s->min_partial = min_t(unsigned long, MAX_PARTIAL, ilog2(s->size) / 2); + s->min_partial = max_t(unsigned long, MIN_PARTIAL, s->min_partial); + + set_cpu_partial(s); + +#ifdef CONFIG_NUMA + s->remote_node_defrag_ratio = 1000; +#endif + + /* Initialize the pre-computed randomized freelist if slab is up */ + if (slab_state >= UP) { + if (init_cache_random_seq(s)) + goto out; + } + + if (!init_kmem_cache_nodes(s)) + goto out; + + if (!alloc_kmem_cache_cpus(s)) + goto out; /* Mutex is not taken during early boot */ - if (slab_state <= UP) - return 0; + if (slab_state <= UP) { + err = 0; + goto out; + } err = sysfs_slab_add(s); - if (err) { - __kmem_cache_release(s); - return err; - } + if (err) + goto out; if (s->flags & SLAB_STORE_USER) debugfs_slab_add(s); - return 0; +out: + if (err) + __kmem_cache_release(s); + return err; } #ifdef SLAB_SUPPORTS_SYSFS diff --git a/net/core/sock.c b/net/core/sock.c index 9abc4fe25953..bbe4c58470c3 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -3429,7 +3429,7 @@ static void sock_def_destruct(struct sock *sk) void sk_send_sigurg(struct sock *sk) { if (sk->sk_socket && sk->sk_socket->file) - if (send_sigurg(&sk->sk_socket->file->f_owner)) + if (send_sigurg(sk->sk_socket->file)) sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI); } EXPORT_SYMBOL(sk_send_sigurg); diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index bfa61e005aac..577e1fcbf6df 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3950,7 +3950,7 @@ static int selinux_file_send_sigiotask(struct task_struct *tsk, struct file_security_struct *fsec; /* struct fown_struct is never outside the context of a struct file */ - file = container_of(fown, struct file, f_owner); + file = fown->file; fsec = selinux_file(file); diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 4164699cd4f6..cb33920ab67c 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -1950,7 +1950,7 @@ static int smack_file_send_sigiotask(struct task_struct *tsk, /* * struct fown_struct is never outside the context of a struct file */ - file = container_of(fown, struct file, f_owner); + file = fown->file; /* we don't log here as rc can be overriden */ blob = smack_file(file);