From 22098763a10d9c1340827fcf6edab66f153b27f0 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 13 Sep 2026 12:27:00 -0700 Subject: Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Don't destroy user event fields when removal fails User event fields are destroyed before the event is removed from visibility. But that can fail leaving the still visible event with no fields. Move the destroying of the fields to after the event is successfully removed from visibility. - Initialize function graph state is fork before calling copy_exec_state() For non-CLONE_VM forks, copy_exec_state() allocates a new task_exec_state. If that allocation fails, ftrace_graph_exit_task() will free the tasks ret_stack pointer. Since that pointer is still using the parent's ret_stack, it mistakenly frees the parent's pointer too. Call ftrace_graph_init() on the task first which will NULL out the new tasks's ret_stack and if the copy fails, it will not free anything. - Remove FGRAPH_MAX_INDEX The macro FGRAPH_MAX_INDEX was added but never used. Remove it. - Save ent_size in function graph printing of nested functions The function graph tracer needs to look at the next event to see if the next event is the return of the current function entry. If it is, it prints a single line: ktime_get(); Otherwise it prints it like a nested function: tick_nohz_irq_exit() { ktime_get(); kcpustat_irq_exit(); } In order to look at the next event, it must save the current event so that it has the information to print from it. It saves the event in the iterator descriptor called "ent". What it doesn't save is the ent_size of the event which is now used to know if the function graph arguments are to be printed. The peek doesn't save the size so the size used happens to be that of the size of the last event that was seen. Save the entry event size in the iterator descriptor so that the correct size is used. - Fix several errors with freeing data in the histogram code The histogram code had a lot of leaked or or incorrect accounting when failures happen. Correct them. - Fix histogram regression of .percent and .graph modifiers Up until 6.3 histogram values could have "percent" or "graph" modifiers that changed how they were printed. But a change that added restricting histograms values from being strings, stack traces and other modifiers inadvertently prevented them from using the percent and graph modifiers, which were legal use cases for values. Put back the percent and graph modifiers. - Fix various typos in the comments - Set the trace_clock before initializing a histogram with clock argument The histogram API allows the user to specific which trace clock to use via a "clock=" string. The histogram is set up first before the clock is checked. If the passed in clock is not valid, it exits without fully fixing up the histogram leaving it on the list and a use-after-free can trigger. Update the clock argument first and if it fails then exit gracefully before the histogram trigger is placed on any lists. - Restore :mod: trailer after parsing in ftrace_set_clr_event The function ftrace_set_clr_event() modifies the parse string and needs to put it back to what was passed in. It searches for ":mod:" via a strsep() but fails to put back the first ':' in the string. Add back the ':' in the passed in string. - Take trace_array reference when opening a tracer options file The options files are dynamically created and some tracers add their own options. When a tracer adds their own list of options, the trace_array holding them has an array to hold the list of options for each tracer. This array increases in size via a krealloc(), and the new entry gets a newly allocated array to hold the options of the new tracer being added. The element in each entry of the tracer's option array holds a pointer back to the trace_array, a pointer to the tracer it is associated to, a pointer to the flags of the option. The issue is that these arrays are freed when the trace_array is freed when its instance it represents is removed from the instances directory. There's a race that an open of one of these options files can happen when the instance is being removed. Add a new helper function to be called by the open function of the options file to iterate all existing trace_arrays under a lock and find the one that has the given option element in one of it's tracer arrays. If found, then update the associated trace_array's reference counter to keep it from being freed. If not found, have the open call return -ENODEV. - Disable interrupts when acquiring the lock in rb_wake_up_waiters() The function rb_wake_up_waiters() assumes it will be called in interrupt context and does not disable irqs when taking cpu_buffer->reader_lock, which can be called in hard interrupt context. The issue is in PREEMPT_RT, this function is called in thread context leaving this lock open to a deadlock. Take the lock with interrupts disabled. - Use rcu_assign_pointer() for tmp_ops filter hash The tmp_ops used in update_ftrace_direct_mod() assigns its filter_hash field directly, but that field is annotated as __rcu and sparse complains. Assign it with rcu_assign_pointer() - Fix use-after-free in enable_trigger_private_data_free() The trace_event_call is accessed through the event_trigger_data's trace_event_file pointer to put the trace_event_call on freeing. The issue is that the trace_event_file data may have been freed already causing a use-after-free. Add a field to the event_trigger_data that points directly to the trace_event_call so that it can decrement its reference directly without needing to go through the trace_event_file. - Fix accounting of buffer data remote headers trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount the number of pages is needed for the asked for size as it doesn't take into account the meta data on each page. Add a helper function to do the calculation properly and use that in these functions. - Catch nr_page_va overflow in ring_buffer_desc sizing The number of pages per remote ring buffer is capped by ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to overflow that field would silently allocate a descriptor smaller than what was asked for. - Do not resize the subbuf order if any per_cpu buffer is disabled The mmapping of ring buffers disables resizing the subbuffers, but it is done per-cpu whereas the subbuf size change is done for all the per_cpu buffers under the buffer->mutex. It could change the size of some while the mapping is happening on others. Have the resize of the subbuf order check all the per_cpu buffers under the lock to see if any of them is disabled before starting and causing an inconsistency between buffers that are being mapped. * tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits) ring-buffer: Check resize_disabled before publishing the new subbuf order tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing tracing/remotes: Account for ring buffer page header in size calculation tracing: Don't dereference trace_event_file in deferred trigger free ftrace: Use rcu_assign_pointer() for tmp_ops filter hash ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters() tracing: Take trace_array reference when opening a tracer options file tracing: Fix ring_buffer_read_page_size() kernel-doc tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event() tracing: Fix memory corruption from a "STACKTRACE" histogram key tracing: Fix memory corruption from the histogram stacktrace modifier tracing: Undo the registration when enabling the histogram trigger fails tracing: Take the reference before publishing the named histogram trigger tracing: Set the trace clock before registering the histogram trigger tracing: Fix typo "preceeded" in comment tracing: Fix typo "availabe" in comment tracing: Let histogram values keep the percent and graph modifiers tracing: Keep the entry count when the histogram stats allocation fails tracing: Free histogram the field rejected for a bad modifier tracing: Free histogram the var ref when its initialization fails ... --- fs/read_write.c | 1822 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1822 insertions(+) create mode 100644 fs/read_write.c (limited to 'fs/read_write.c') diff --git a/fs/read_write.c b/fs/read_write.c new file mode 100644 index 000000000..e8c14e276 --- /dev/null +++ b/fs/read_write.c @@ -0,0 +1,1822 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/read_write.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "internal.h" + +#include +#include + +const struct file_operations generic_ro_fops = { + .llseek = generic_file_llseek, + .read_iter = generic_file_read_iter, + .mmap_prepare = generic_file_readonly_mmap_prepare, + .splice_read = filemap_splice_read, + .setlease = generic_setlease, +}; + +EXPORT_SYMBOL(generic_ro_fops); + +static inline bool unsigned_offsets(struct file *file) +{ + return file->f_op->fop_flags & FOP_UNSIGNED_OFFSET; +} + +/** + * vfs_setpos_cookie - update the file offset for lseek and reset cookie + * @file: file structure in question + * @offset: file offset to seek to + * @maxsize: maximum file size + * @cookie: cookie to reset + * + * Update the file offset to the value specified by @offset if the given + * offset is valid and it is not equal to the current file offset and + * reset the specified cookie to indicate that a seek happened. + * + * Return the specified offset on success and -EINVAL on invalid offset. + */ +static loff_t vfs_setpos_cookie(struct file *file, loff_t offset, + loff_t maxsize, u64 *cookie) +{ + if (offset < 0 && !unsigned_offsets(file)) + return -EINVAL; + if (offset > maxsize) + return -EINVAL; + + if (offset != file->f_pos) { + file->f_pos = offset; + if (cookie) + *cookie = 0; + } + return offset; +} + +/** + * vfs_setpos - update the file offset for lseek + * @file: file structure in question + * @offset: file offset to seek to + * @maxsize: maximum file size + * + * This is a low-level filesystem helper for updating the file offset to + * the value specified by @offset if the given offset is valid and it is + * not equal to the current file offset. + * + * Return the specified offset on success and -EINVAL on invalid offset. + */ +loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize) +{ + return vfs_setpos_cookie(file, offset, maxsize, NULL); +} +EXPORT_SYMBOL(vfs_setpos); + +/** + * must_set_pos - check whether f_pos has to be updated + * @file: file to seek on + * @offset: offset to use + * @whence: type of seek operation + * @eof: end of file + * + * Check whether f_pos needs to be updated and update @offset according + * to @whence. + * + * Return: 0 if f_pos doesn't need to be updated, 1 if f_pos has to be + * updated, and negative error code on failure. + */ +static int must_set_pos(struct file *file, loff_t *offset, int whence, loff_t eof) +{ + switch (whence) { + case SEEK_END: + *offset += eof; + break; + case SEEK_CUR: + /* + * Here we special-case the lseek(fd, 0, SEEK_CUR) + * position-querying operation. Avoid rewriting the "same" + * f_pos value back to the file because a concurrent read(), + * write() or lseek() might have altered it + */ + if (*offset == 0) { + *offset = file->f_pos; + return 0; + } + break; + case SEEK_DATA: + /* + * In the generic case the entire file is data, so as long as + * offset isn't at the end of the file then the offset is data. + */ + if ((unsigned long long)*offset >= eof) + return -ENXIO; + break; + case SEEK_HOLE: + /* + * There is a virtual hole at the end of the file, so as long as + * offset isn't i_size or larger, return i_size. + */ + if ((unsigned long long)*offset >= eof) + return -ENXIO; + *offset = eof; + break; + } + + return 1; +} + +/** + * generic_file_llseek_size - generic llseek implementation for regular files + * @file: file structure to seek on + * @offset: file offset to seek to + * @whence: type of seek + * @maxsize: max size of this file in file system + * @eof: offset used for SEEK_END position + * + * This is a variant of generic_file_llseek that allows passing in a custom + * maximum file size and a custom EOF position, for e.g. hashed directories + * + * Synchronization: + * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms) + * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes. + * read/writes behave like SEEK_SET against seeks. + */ +loff_t +generic_file_llseek_size(struct file *file, loff_t offset, int whence, + loff_t maxsize, loff_t eof) +{ + int ret; + + ret = must_set_pos(file, &offset, whence, eof); + if (ret < 0) + return ret; + if (ret == 0) + return offset; + + if (whence == SEEK_CUR) { + /* + * If the file requires locking via f_pos_lock we know + * that mutual exclusion for SEEK_CUR on the same file + * is guaranteed. If the file isn't locked, we take + * f_lock to protect against f_pos races with other + * SEEK_CURs. + */ + if (file_seek_cur_needs_f_lock(file)) { + guard(spinlock)(&file->f_lock); + return vfs_setpos(file, file->f_pos + offset, maxsize); + } + return vfs_setpos(file, file->f_pos + offset, maxsize); + } + + return vfs_setpos(file, offset, maxsize); +} +EXPORT_SYMBOL(generic_file_llseek_size); + +/** + * generic_llseek_cookie - versioned llseek implementation + * @file: file structure to seek on + * @offset: file offset to seek to + * @whence: type of seek + * @cookie: cookie to update + * + * See generic_file_llseek for a general description and locking assumptions. + * + * In contrast to generic_file_llseek, this function also resets a + * specified cookie to indicate a seek took place. + */ +loff_t generic_llseek_cookie(struct file *file, loff_t offset, int whence, + u64 *cookie) +{ + struct inode *inode = file->f_mapping->host; + loff_t maxsize = inode->i_sb->s_maxbytes; + loff_t eof = i_size_read(inode); + int ret; + + if (WARN_ON_ONCE(!cookie)) + return -EINVAL; + + /* + * Require that this is only used for directories that guarantee + * synchronization between readdir and seek so that an update to + * @cookie is correctly synchronized with concurrent readdir. + */ + if (WARN_ON_ONCE(!(file->f_mode & FMODE_ATOMIC_POS))) + return -EINVAL; + + ret = must_set_pos(file, &offset, whence, eof); + if (ret < 0) + return ret; + if (ret == 0) + return offset; + + /* No need to hold f_lock because we know that f_pos_lock is held. */ + if (whence == SEEK_CUR) + return vfs_setpos_cookie(file, file->f_pos + offset, maxsize, cookie); + + return vfs_setpos_cookie(file, offset, maxsize, cookie); +} +EXPORT_SYMBOL(generic_llseek_cookie); + +/** + * generic_file_llseek - generic llseek implementation for regular files + * @file: file structure to seek on + * @offset: file offset to seek to + * @whence: type of seek + * + * This is a generic implementation of ->llseek useable for all normal local + * filesystems. It just updates the file offset to the value specified by + * @offset and @whence. + */ +loff_t generic_file_llseek(struct file *file, loff_t offset, int whence) +{ + struct inode *inode = file->f_mapping->host; + + return generic_file_llseek_size(file, offset, whence, + inode->i_sb->s_maxbytes, + i_size_read(inode)); +} +EXPORT_SYMBOL(generic_file_llseek); + +/** + * fixed_size_llseek - llseek implementation for fixed-sized devices + * @file: file structure to seek on + * @offset: file offset to seek to + * @whence: type of seek + * @size: size of the file + * + */ +loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size) +{ + switch (whence) { + case SEEK_SET: case SEEK_CUR: case SEEK_END: + return generic_file_llseek_size(file, offset, whence, + size, size); + default: + return -EINVAL; + } +} +EXPORT_SYMBOL(fixed_size_llseek); + +/** + * no_seek_end_llseek - llseek implementation for fixed-sized devices + * @file: file structure to seek on + * @offset: file offset to seek to + * @whence: type of seek + * + */ +loff_t no_seek_end_llseek(struct file *file, loff_t offset, int whence) +{ + switch (whence) { + case SEEK_SET: case SEEK_CUR: + return generic_file_llseek_size(file, offset, whence, + OFFSET_MAX, 0); + default: + return -EINVAL; + } +} +EXPORT_SYMBOL(no_seek_end_llseek); + +/** + * no_seek_end_llseek_size - llseek implementation for fixed-sized devices + * @file: file structure to seek on + * @offset: file offset to seek to + * @whence: type of seek + * @size: maximal offset allowed + * + */ +loff_t no_seek_end_llseek_size(struct file *file, loff_t offset, int whence, loff_t size) +{ + switch (whence) { + case SEEK_SET: case SEEK_CUR: + return generic_file_llseek_size(file, offset, whence, + size, 0); + default: + return -EINVAL; + } +} +EXPORT_SYMBOL(no_seek_end_llseek_size); + +/** + * noop_llseek - No Operation Performed llseek implementation + * @file: file structure to seek on + * @offset: file offset to seek to + * @whence: type of seek + * + * This is an implementation of ->llseek useable for the rare special case when + * userspace expects the seek to succeed but the (device) file is actually not + * able to perform the seek. In this case you use noop_llseek() instead of + * falling back to the default implementation of ->llseek. + */ +loff_t noop_llseek(struct file *file, loff_t offset, int whence) +{ + return file->f_pos; +} +EXPORT_SYMBOL(noop_llseek); + +loff_t default_llseek(struct file *file, loff_t offset, int whence) +{ + struct inode *inode = file_inode(file); + loff_t retval; + + retval = inode_lock_killable(inode); + if (retval) + return retval; + switch (whence) { + case SEEK_END: + offset += i_size_read(inode); + break; + case SEEK_CUR: + if (offset == 0) { + retval = file->f_pos; + goto out; + } + offset += file->f_pos; + break; + case SEEK_DATA: + /* + * In the generic case the entire file is data, so as + * long as offset isn't at the end of the file then the + * offset is data. + */ + if (offset >= inode->i_size) { + retval = -ENXIO; + goto out; + } + break; + case SEEK_HOLE: + /* + * There is a virtual hole at the end of the file, so + * as long as offset isn't i_size or larger, return + * i_size. + */ + if (offset >= inode->i_size) { + retval = -ENXIO; + goto out; + } + offset = inode->i_size; + break; + } + retval = -EINVAL; + if (offset >= 0 || unsigned_offsets(file)) { + if (offset != file->f_pos) + file->f_pos = offset; + retval = offset; + } +out: + inode_unlock(inode); + return retval; +} +EXPORT_SYMBOL(default_llseek); + +loff_t vfs_llseek(struct file *file, loff_t offset, int whence) +{ + if (!(file->f_mode & FMODE_LSEEK)) + return -ESPIPE; + return file->f_op->llseek(file, offset, whence); +} +EXPORT_SYMBOL(vfs_llseek); + +static off_t ksys_lseek(unsigned int fd, off_t offset, unsigned int whence) +{ + off_t retval; + CLASS(fd_pos, f)(fd); + if (fd_empty(f)) + return -EBADF; + + retval = -EINVAL; + if (whence <= SEEK_MAX) { + loff_t res = vfs_llseek(fd_file(f), offset, whence); + retval = res; + if (res != (loff_t)retval) + retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ + } + return retval; +} + +SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence) +{ + return ksys_lseek(fd, offset, whence); +} + +#ifdef CONFIG_COMPAT +COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence) +{ + return ksys_lseek(fd, offset, whence); +} +#endif + +#if !defined(CONFIG_64BIT) || defined(CONFIG_COMPAT) || \ + defined(__ARCH_WANT_SYS_LLSEEK) +SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, + unsigned long, offset_low, loff_t __user *, result, + unsigned int, whence) +{ + int retval; + CLASS(fd_pos, f)(fd); + loff_t offset; + + if (fd_empty(f)) + return -EBADF; + + if (whence > SEEK_MAX) + return -EINVAL; + + offset = vfs_llseek(fd_file(f), ((loff_t) offset_high << 32) | offset_low, + whence); + + retval = (int)offset; + if (offset >= 0) { + retval = -EFAULT; + if (!copy_to_user(result, &offset, sizeof(offset))) + retval = 0; + } + return retval; +} +#endif + +int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count) +{ + int mask = read_write == READ ? MAY_READ : MAY_WRITE; + int ret; + + if (unlikely((ssize_t) count < 0)) + return -EINVAL; + + if (ppos) { + loff_t pos = *ppos; + + if (unlikely(pos < 0)) { + if (!unsigned_offsets(file)) + return -EINVAL; + if (count >= -pos) /* both values are in 0..LLONG_MAX */ + return -EOVERFLOW; + } else if (unlikely((loff_t) (pos + count) < 0)) { + if (!unsigned_offsets(file)) + return -EINVAL; + } + } + + ret = security_file_permission(file, mask); + if (ret) + return ret; + + return fsnotify_file_area_perm(file, mask, ppos, count); +} +EXPORT_SYMBOL(rw_verify_area); + +static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) +{ + struct kiocb kiocb; + struct iov_iter iter; + ssize_t ret; + + init_sync_kiocb(&kiocb, filp); + kiocb.ki_pos = (ppos ? *ppos : 0); + iov_iter_ubuf(&iter, ITER_DEST, buf, len); + + ret = filp->f_op->read_iter(&kiocb, &iter); + BUG_ON(ret == -EIOCBQUEUED); + if (ppos) + *ppos = kiocb.ki_pos; + return ret; +} + +static int warn_unsupported(struct file *file, const char *op) +{ + pr_warn_ratelimited( + "kernel %s not supported for file %pD4 (pid: %d comm: %.20s)\n", + op, file, current->pid, current->comm); + return -EINVAL; +} + +ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) +{ + struct kvec iov = { + .iov_base = buf, + .iov_len = min_t(size_t, count, MAX_RW_COUNT), + }; + struct kiocb kiocb; + struct iov_iter iter; + ssize_t ret; + + if (WARN_ON_ONCE(!(file->f_mode & FMODE_READ))) + return -EINVAL; + if (!(file->f_mode & FMODE_CAN_READ)) + return -EINVAL; + /* + * Also fail if ->read_iter and ->read are both wired up as that + * implies very convoluted semantics. + */ + if (unlikely(!file->f_op->read_iter || file->f_op->read)) + return warn_unsupported(file, "read"); + + init_sync_kiocb(&kiocb, file); + kiocb.ki_pos = pos ? *pos : 0; + iov_iter_kvec(&iter, ITER_DEST, &iov, 1, iov.iov_len); + ret = file->f_op->read_iter(&kiocb, &iter); + if (ret > 0) { + if (pos) + *pos = kiocb.ki_pos; + fsnotify_access(file); + add_rchar(current, ret); + } + inc_syscr(current); + return ret; +} + +ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) +{ + ssize_t ret; + + ret = rw_verify_area(READ, file, pos, count); + if (ret) + return ret; + return __kernel_read(file, buf, count, pos); +} +EXPORT_SYMBOL(kernel_read); + +ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) +{ + ssize_t ret; + + if (!(file->f_mode & FMODE_READ)) + return -EBADF; + if (!(file->f_mode & FMODE_CAN_READ)) + return -EINVAL; + if (unlikely(!access_ok(buf, count))) + return -EFAULT; + + ret = rw_verify_area(READ, file, pos, count); + if (ret) + return ret; + if (count > MAX_RW_COUNT) + count = MAX_RW_COUNT; + + if (file->f_op->read) + ret = file->f_op->read(file, buf, count, pos); + else if (file->f_op->read_iter) + ret = new_sync_read(file, buf, count, pos); + else + ret = -EINVAL; + if (ret > 0) { + fsnotify_access(file); + add_rchar(current, ret); + } + inc_syscr(current); + return ret; +} + +static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos) +{ + struct kiocb kiocb; + struct iov_iter iter; + ssize_t ret; + + init_sync_kiocb(&kiocb, filp); + kiocb.ki_pos = (ppos ? *ppos : 0); + iov_iter_ubuf(&iter, ITER_SOURCE, (void __user *)buf, len); + + ret = filp->f_op->write_iter(&kiocb, &iter); + BUG_ON(ret == -EIOCBQUEUED); + if (ret > 0 && ppos) + *ppos = kiocb.ki_pos; + return ret; +} + +/* caller is responsible for file_start_write/file_end_write */ +ssize_t __kernel_write_iter(struct file *file, struct iov_iter *from, loff_t *pos) +{ + struct kiocb kiocb; + ssize_t ret; + + if (WARN_ON_ONCE(!(file->f_mode & FMODE_WRITE))) + return -EBADF; + if (!(file->f_mode & FMODE_CAN_WRITE)) + return -EINVAL; + /* + * Also fail if ->write_iter and ->write are both wired up as that + * implies very convoluted semantics. + */ + if (unlikely(!file->f_op->write_iter || file->f_op->write)) + return warn_unsupported(file, "write"); + + init_sync_kiocb(&kiocb, file); + kiocb.ki_pos = pos ? *pos : 0; + ret = file->f_op->write_iter(&kiocb, from); + if (ret > 0) { + if (pos) + *pos = kiocb.ki_pos; + fsnotify_modify(file); + add_wchar(current, ret); + } + inc_syscw(current); + return ret; +} + +/* caller is responsible for file_start_write/file_end_write */ +ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos) +{ + struct kvec iov = { + .iov_base = (void *)buf, + .iov_len = min_t(size_t, count, MAX_RW_COUNT), + }; + struct iov_iter iter; + iov_iter_kvec(&iter, ITER_SOURCE, &iov, 1, iov.iov_len); + return __kernel_write_iter(file, &iter, pos); +} +/* + * autofs is one of the few internal kernel users that actually + * wants this _and_ can be built as a module. So we need to export + * this symbol for autofs, even though it really isn't appropriate + * for any other kernel modules. + */ +EXPORT_SYMBOL_FOR_MODULES(__kernel_write, "autofs4"); + +ssize_t kernel_write(struct file *file, const void *buf, size_t count, + loff_t *pos) +{ + ssize_t ret; + + ret = rw_verify_area(WRITE, file, pos, count); + if (ret) + return ret; + + file_start_write(file); + ret = __kernel_write(file, buf, count, pos); + file_end_write(file); + return ret; +} +EXPORT_SYMBOL(kernel_write); + +ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) +{ + ssize_t ret; + + if (!(file->f_mode & FMODE_WRITE)) + return -EBADF; + if (!(file->f_mode & FMODE_CAN_WRITE)) + return -EINVAL; + if (unlikely(!access_ok(buf, count))) + return -EFAULT; + + ret = rw_verify_area(WRITE, file, pos, count); + if (ret) + return ret; + if (count > MAX_RW_COUNT) + count = MAX_RW_COUNT; + file_start_write(file); + if (file->f_op->write) + ret = file->f_op->write(file, buf, count, pos); + else if (file->f_op->write_iter) + ret = new_sync_write(file, buf, count, pos); + else + ret = -EINVAL; + if (ret > 0) { + fsnotify_modify(file); + add_wchar(current, ret); + } + inc_syscw(current); + file_end_write(file); + return ret; +} + +/* file_ppos returns &file->f_pos or NULL if file is stream */ +static inline loff_t *file_ppos(struct file *file) +{ + return file->f_mode & FMODE_STREAM ? NULL : &file->f_pos; +} + +ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count) +{ + CLASS(fd_pos, f)(fd); + ssize_t ret = -EBADF; + + if (!fd_empty(f)) { + loff_t pos, *ppos = file_ppos(fd_file(f)); + if (ppos) { + pos = *ppos; + ppos = &pos; + } + ret = vfs_read(fd_file(f), buf, count, ppos); + if (ret >= 0 && ppos) + fd_file(f)->f_pos = pos; + } + return ret; +} + +SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) +{ + return ksys_read(fd, buf, count); +} + +ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count) +{ + CLASS(fd_pos, f)(fd); + ssize_t ret = -EBADF; + + if (!fd_empty(f)) { + loff_t pos, *ppos = file_ppos(fd_file(f)); + if (ppos) { + pos = *ppos; + ppos = &pos; + } + ret = vfs_write(fd_file(f), buf, count, ppos); + if (ret >= 0 && ppos) + fd_file(f)->f_pos = pos; + } + + return ret; +} + +SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, + size_t, count) +{ + return ksys_write(fd, buf, count); +} + +ssize_t ksys_pread64(unsigned int fd, char __user *buf, size_t count, + loff_t pos) +{ + if (pos < 0) + return -EINVAL; + + CLASS(fd, f)(fd); + if (fd_empty(f)) + return -EBADF; + + if (fd_file(f)->f_mode & FMODE_PREAD) + return vfs_read(fd_file(f), buf, count, &pos); + + return -ESPIPE; +} + +SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf, + size_t, count, loff_t, pos) +{ + return ksys_pread64(fd, buf, count, pos); +} + +#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_PREAD64) +COMPAT_SYSCALL_DEFINE5(pread64, unsigned int, fd, char __user *, buf, + size_t, count, compat_arg_u64_dual(pos)) +{ + return ksys_pread64(fd, buf, count, compat_arg_u64_glue(pos)); +} +#endif + +ssize_t ksys_pwrite64(unsigned int fd, const char __user *buf, + size_t count, loff_t pos) +{ + if (pos < 0) + return -EINVAL; + + CLASS(fd, f)(fd); + if (fd_empty(f)) + return -EBADF; + + if (fd_file(f)->f_mode & FMODE_PWRITE) + return vfs_write(fd_file(f), buf, count, &pos); + + return -ESPIPE; +} + +SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf, + size_t, count, loff_t, pos) +{ + return ksys_pwrite64(fd, buf, count, pos); +} + +#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_PWRITE64) +COMPAT_SYSCALL_DEFINE5(pwrite64, unsigned int, fd, const char __user *, buf, + size_t, count, compat_arg_u64_dual(pos)) +{ + return ksys_pwrite64(fd, buf, count, compat_arg_u64_glue(pos)); +} +#endif + +static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, + loff_t *ppos, int type, rwf_t flags) +{ + struct kiocb kiocb; + ssize_t ret; + + init_sync_kiocb(&kiocb, filp); + ret = kiocb_set_rw_flags(&kiocb, flags, type); + if (ret) + return ret; + kiocb.ki_pos = (ppos ? *ppos : 0); + + if (type == READ) + ret = filp->f_op->read_iter(&kiocb, iter); + else + ret = filp->f_op->write_iter(&kiocb, iter); + BUG_ON(ret == -EIOCBQUEUED); + if (ppos) + *ppos = kiocb.ki_pos; + return ret; +} + +/* Do it by hand, with file-ops */ +static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, + loff_t *ppos, int type, rwf_t flags) +{ + ssize_t ret = 0; + + if (flags & ~RWF_HIPRI) + return -EOPNOTSUPP; + + while (iov_iter_count(iter)) { + ssize_t nr; + + if (type == READ) { + nr = filp->f_op->read(filp, iter_iov_addr(iter), + iter_iov_len(iter), ppos); + } else { + nr = filp->f_op->write(filp, iter_iov_addr(iter), + iter_iov_len(iter), ppos); + } + + if (nr < 0) { + if (!ret) + ret = nr; + break; + } + ret += nr; + if (nr != iter_iov_len(iter)) + break; + iov_iter_advance(iter, nr); + } + + return ret; +} + +ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb, + struct iov_iter *iter) +{ + size_t tot_len; + ssize_t ret = 0; + + if (!file->f_op->read_iter) + return -EINVAL; + if (!(file->f_mode & FMODE_READ)) + return -EBADF; + if (!(file->f_mode & FMODE_CAN_READ)) + return -EINVAL; + + tot_len = iov_iter_count(iter); + if (!tot_len) + goto out; + ret = rw_verify_area(READ, file, &iocb->ki_pos, tot_len); + if (ret < 0) + return ret; + + ret = file->f_op->read_iter(iocb, iter); +out: + if (ret >= 0) + fsnotify_access(file); + return ret; +} +EXPORT_SYMBOL(vfs_iocb_iter_read); + +ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos, + rwf_t flags) +{ + size_t tot_len; + ssize_t ret = 0; + + if (!file->f_op->read_iter) + return -EINVAL; + if (!(file->f_mode & FMODE_READ)) + return -EBADF; + if (!(file->f_mode & FMODE_CAN_READ)) + return -EINVAL; + + tot_len = iov_iter_count(iter); + if (!tot_len) + goto out; + ret = rw_verify_area(READ, file, ppos, tot_len); + if (ret < 0) + return ret; + + ret = do_iter_readv_writev(file, iter, ppos, READ, flags); +out: + if (ret >= 0) + fsnotify_access(file); + return ret; +} +EXPORT_SYMBOL(vfs_iter_read); + +/* + * Caller is responsible for calling kiocb_end_write() on completion + * if async iocb was queued. + */ +ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb, + struct iov_iter *iter) +{ + size_t tot_len; + ssize_t ret = 0; + + if (!file->f_op->write_iter) + return -EINVAL; + if (!(file->f_mode & FMODE_WRITE)) + return -EBADF; + if (!(file->f_mode & FMODE_CAN_WRITE)) + return -EINVAL; + + tot_len = iov_iter_count(iter); + if (!tot_len) + return 0; + ret = rw_verify_area(WRITE, file, &iocb->ki_pos, tot_len); + if (ret < 0) + return ret; + + kiocb_start_write(iocb); + ret = file->f_op->write_iter(iocb, iter); + if (ret != -EIOCBQUEUED) + kiocb_end_write(iocb); + if (ret > 0) + fsnotify_modify(file); + + return ret; +} +EXPORT_SYMBOL(vfs_iocb_iter_write); + +ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos, + rwf_t flags) +{ + size_t tot_len; + ssize_t ret; + + if (!(file->f_mode & FMODE_WRITE)) + return -EBADF; + if (!(file->f_mode & FMODE_CAN_WRITE)) + return -EINVAL; + if (!file->f_op->write_iter) + return -EINVAL; + + tot_len = iov_iter_count(iter); + if (!tot_len) + return 0; + + ret = rw_verify_area(WRITE, file, ppos, tot_len); + if (ret < 0) + return ret; + + file_start_write(file); + ret = do_iter_readv_writev(file, iter, ppos, WRITE, flags); + if (ret > 0) + fsnotify_modify(file); + file_end_write(file); + + return ret; +} +EXPORT_SYMBOL(vfs_iter_write); + +static ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, + unsigned long vlen, loff_t *pos, rwf_t flags) +{ + struct iovec iovstack[UIO_FASTIOV]; + struct iovec *iov = iovstack; + struct iov_iter iter; + size_t tot_len; + ssize_t ret = 0; + + if (!(file->f_mode & FMODE_READ)) + return -EBADF; + if (!(file->f_mode & FMODE_CAN_READ)) + return -EINVAL; + + ret = import_iovec(ITER_DEST, vec, vlen, ARRAY_SIZE(iovstack), &iov, + &iter); + if (ret < 0) + return ret; + + tot_len = iov_iter_count(&iter); + if (!tot_len) + goto out; + + ret = rw_verify_area(READ, file, pos, tot_len); + if (ret < 0) + goto out; + + if (file->f_op->read_iter) + ret = do_iter_readv_writev(file, &iter, pos, READ, flags); + else + ret = do_loop_readv_writev(file, &iter, pos, READ, flags); +out: + if (ret >= 0) + fsnotify_access(file); + kfree(iov); + return ret; +} + +static ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, + unsigned long vlen, loff_t *pos, rwf_t flags) +{ + struct iovec iovstack[UIO_FASTIOV]; + struct iovec *iov = iovstack; + struct iov_iter iter; + size_t tot_len; + ssize_t ret = 0; + + if (!(file->f_mode & FMODE_WRITE)) + return -EBADF; + if (!(file->f_mode & FMODE_CAN_WRITE)) + return -EINVAL; + + ret = import_iovec(ITER_SOURCE, vec, vlen, ARRAY_SIZE(iovstack), &iov, + &iter); + if (ret < 0) + return ret; + + tot_len = iov_iter_count(&iter); + if (!tot_len) + goto out; + + ret = rw_verify_area(WRITE, file, pos, tot_len); + if (ret < 0) + goto out; + + file_start_write(file); + if (file->f_op->write_iter) + ret = do_iter_readv_writev(file, &iter, pos, WRITE, flags); + else + ret = do_loop_readv_writev(file, &iter, pos, WRITE, flags); + if (ret > 0) + fsnotify_modify(file); + file_end_write(file); +out: + kfree(iov); + return ret; +} + +static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec, + unsigned long vlen, rwf_t flags) +{ + CLASS(fd_pos, f)(fd); + ssize_t ret = -EBADF; + + if (!fd_empty(f)) { + loff_t pos, *ppos = file_ppos(fd_file(f)); + if (ppos) { + pos = *ppos; + ppos = &pos; + } + ret = vfs_readv(fd_file(f), vec, vlen, ppos, flags); + if (ret >= 0 && ppos) + fd_file(f)->f_pos = pos; + } + + if (ret > 0) + add_rchar(current, ret); + inc_syscr(current); + return ret; +} + +static ssize_t do_writev(unsigned long fd, const struct iovec __user *vec, + unsigned long vlen, rwf_t flags) +{ + CLASS(fd_pos, f)(fd); + ssize_t ret = -EBADF; + + if (!fd_empty(f)) { + loff_t pos, *ppos = file_ppos(fd_file(f)); + if (ppos) { + pos = *ppos; + ppos = &pos; + } + ret = vfs_writev(fd_file(f), vec, vlen, ppos, flags); + if (ret >= 0 && ppos) + fd_file(f)->f_pos = pos; + } + + if (ret > 0) + add_wchar(current, ret); + inc_syscw(current); + return ret; +} + +static inline loff_t pos_from_hilo(unsigned long high, unsigned long low) +{ +#define HALF_LONG_BITS (BITS_PER_LONG / 2) + return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low; +} + +static ssize_t do_preadv(unsigned long fd, const struct iovec __user *vec, + unsigned long vlen, loff_t pos, rwf_t flags) +{ + ssize_t ret = -EBADF; + + if (pos < 0) + return -EINVAL; + + CLASS(fd, f)(fd); + if (!fd_empty(f)) { + ret = -ESPIPE; + if (fd_file(f)->f_mode & FMODE_PREAD) + ret = vfs_readv(fd_file(f), vec, vlen, &pos, flags); + } + + if (ret > 0) + add_rchar(current, ret); + inc_syscr(current); + return ret; +} + +static ssize_t do_pwritev(unsigned long fd, const struct iovec __user *vec, + unsigned long vlen, loff_t pos, rwf_t flags) +{ + ssize_t ret = -EBADF; + + if (pos < 0) + return -EINVAL; + + CLASS(fd, f)(fd); + if (!fd_empty(f)) { + ret = -ESPIPE; + if (fd_file(f)->f_mode & FMODE_PWRITE) + ret = vfs_writev(fd_file(f), vec, vlen, &pos, flags); + } + + if (ret > 0) + add_wchar(current, ret); + inc_syscw(current); + return ret; +} + +SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, + unsigned long, vlen) +{ + return do_readv(fd, vec, vlen, 0); +} + +SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, + unsigned long, vlen) +{ + return do_writev(fd, vec, vlen, 0); +} + +SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec, + unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) +{ + loff_t pos = pos_from_hilo(pos_h, pos_l); + + return do_preadv(fd, vec, vlen, pos, 0); +} + +SYSCALL_DEFINE6(preadv2, unsigned long, fd, const struct iovec __user *, vec, + unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h, + rwf_t, flags) +{ + loff_t pos = pos_from_hilo(pos_h, pos_l); + + if (pos == -1) + return do_readv(fd, vec, vlen, flags); + + return do_preadv(fd, vec, vlen, pos, flags); +} + +SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, + unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h) +{ + loff_t pos = pos_from_hilo(pos_h, pos_l); + + return do_pwritev(fd, vec, vlen, pos, 0); +} + +SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec, + unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h, + rwf_t, flags) +{ + loff_t pos = pos_from_hilo(pos_h, pos_l); + + if (pos == -1) + return do_writev(fd, vec, vlen, flags); + + return do_pwritev(fd, vec, vlen, pos, flags); +} + +/* + * Various compat syscalls. Note that they all pretend to take a native + * iovec - import_iovec will properly treat those as compat_iovecs based on + * in_compat_syscall(). + */ +#ifdef CONFIG_COMPAT +#ifdef __ARCH_WANT_COMPAT_SYS_PREADV64 +COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, + const struct iovec __user *, vec, + unsigned long, vlen, loff_t, pos) +{ + return do_preadv(fd, vec, vlen, pos, 0); +} +#endif + +COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd, + const struct iovec __user *, vec, + compat_ulong_t, vlen, u32, pos_low, u32, pos_high) +{ + loff_t pos = ((loff_t)pos_high << 32) | pos_low; + + return do_preadv(fd, vec, vlen, pos, 0); +} + +#ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2 +COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd, + const struct iovec __user *, vec, + unsigned long, vlen, loff_t, pos, rwf_t, flags) +{ + if (pos == -1) + return do_readv(fd, vec, vlen, flags); + return do_preadv(fd, vec, vlen, pos, flags); +} +#endif + +COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd, + const struct iovec __user *, vec, + compat_ulong_t, vlen, u32, pos_low, u32, pos_high, + rwf_t, flags) +{ + loff_t pos = ((loff_t)pos_high << 32) | pos_low; + + if (pos == -1) + return do_readv(fd, vec, vlen, flags); + return do_preadv(fd, vec, vlen, pos, flags); +} + +#ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64 +COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd, + const struct iovec __user *, vec, + unsigned long, vlen, loff_t, pos) +{ + return do_pwritev(fd, vec, vlen, pos, 0); +} +#endif + +COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd, + const struct iovec __user *,vec, + compat_ulong_t, vlen, u32, pos_low, u32, pos_high) +{ + loff_t pos = ((loff_t)pos_high << 32) | pos_low; + + return do_pwritev(fd, vec, vlen, pos, 0); +} + +#ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2 +COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd, + const struct iovec __user *, vec, + unsigned long, vlen, loff_t, pos, rwf_t, flags) +{ + if (pos == -1) + return do_writev(fd, vec, vlen, flags); + return do_pwritev(fd, vec, vlen, pos, flags); +} +#endif + +COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd, + const struct iovec __user *,vec, + compat_ulong_t, vlen, u32, pos_low, u32, pos_high, rwf_t, flags) +{ + loff_t pos = ((loff_t)pos_high << 32) | pos_low; + + if (pos == -1) + return do_writev(fd, vec, vlen, flags); + return do_pwritev(fd, vec, vlen, pos, flags); +} +#endif /* CONFIG_COMPAT */ + +static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, + size_t count, loff_t max) +{ + struct inode *in_inode, *out_inode; + struct pipe_inode_info *opipe; + loff_t pos; + loff_t out_pos; + ssize_t retval; + int fl; + + /* + * Get input file, and verify that it is ok.. + */ + CLASS(fd, in)(in_fd); + if (fd_empty(in)) + return -EBADF; + if (!(fd_file(in)->f_mode & FMODE_READ)) + return -EBADF; + if (!ppos) { + pos = fd_file(in)->f_pos; + } else { + pos = *ppos; + if (!(fd_file(in)->f_mode & FMODE_PREAD)) + return -ESPIPE; + } + retval = rw_verify_area(READ, fd_file(in), &pos, count); + if (retval < 0) + return retval; + if (count > MAX_RW_COUNT) + count = MAX_RW_COUNT; + + /* + * Get output file, and verify that it is ok.. + */ + CLASS(fd, out)(out_fd); + if (fd_empty(out)) + return -EBADF; + if (!(fd_file(out)->f_mode & FMODE_WRITE)) + return -EBADF; + in_inode = file_inode(fd_file(in)); + out_inode = file_inode(fd_file(out)); + out_pos = fd_file(out)->f_pos; + + if (!max) + max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); + + if (unlikely(pos + count > max)) { + if (pos >= max) + return -EOVERFLOW; + count = max - pos; + } + + fl = 0; +#if 0 + /* + * We need to debate whether we can enable this or not. The + * man page documents EAGAIN return for the output at least, + * and the application is arguably buggy if it doesn't expect + * EAGAIN on a non-blocking file descriptor. + */ + if (fd_file(in)->f_flags & O_NONBLOCK) + fl = SPLICE_F_NONBLOCK; +#endif + opipe = get_pipe_info(fd_file(out), true); + if (!opipe) { + retval = rw_verify_area(WRITE, fd_file(out), &out_pos, count); + if (retval < 0) + return retval; + retval = do_splice_direct(fd_file(in), &pos, fd_file(out), &out_pos, + count, fl); + } else { + if (fd_file(out)->f_flags & O_NONBLOCK) + fl |= SPLICE_F_NONBLOCK; + + retval = splice_file_to_pipe(fd_file(in), opipe, &pos, count, fl); + } + + if (retval > 0) { + add_rchar(current, retval); + add_wchar(current, retval); + fsnotify_access(fd_file(in)); + fsnotify_modify(fd_file(out)); + fd_file(out)->f_pos = out_pos; + if (ppos) + *ppos = pos; + else + fd_file(in)->f_pos = pos; + } + + inc_syscr(current); + inc_syscw(current); + if (pos > max) + retval = -EOVERFLOW; + return retval; +} + +SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count) +{ + loff_t pos; + off_t off; + ssize_t ret; + + if (offset) { + if (unlikely(get_user(off, offset))) + return -EFAULT; + pos = off; + ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); + if (unlikely(put_user(pos, offset))) + return -EFAULT; + return ret; + } + + return do_sendfile(out_fd, in_fd, NULL, count, 0); +} + +SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count) +{ + loff_t pos; + ssize_t ret; + + if (offset) { + if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) + return -EFAULT; + ret = do_sendfile(out_fd, in_fd, &pos, count, 0); + if (unlikely(put_user(pos, offset))) + return -EFAULT; + return ret; + } + + return do_sendfile(out_fd, in_fd, NULL, count, 0); +} + +#ifdef CONFIG_COMPAT +COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, + compat_off_t __user *, offset, compat_size_t, count) +{ + loff_t pos; + off_t off; + ssize_t ret; + + if (offset) { + if (unlikely(get_user(off, offset))) + return -EFAULT; + pos = off; + ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); + if (unlikely(put_user(pos, offset))) + return -EFAULT; + return ret; + } + + return do_sendfile(out_fd, in_fd, NULL, count, 0); +} + +COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, + compat_loff_t __user *, offset, compat_size_t, count) +{ + loff_t pos; + ssize_t ret; + + if (offset) { + if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t)))) + return -EFAULT; + ret = do_sendfile(out_fd, in_fd, &pos, count, 0); + if (unlikely(put_user(pos, offset))) + return -EFAULT; + return ret; + } + + return do_sendfile(out_fd, in_fd, NULL, count, 0); +} +#endif + +/* + * Performs necessary checks before doing a file copy + * + * Can adjust amount of bytes to copy via @req_count argument. + * Returns appropriate error code that caller should return or + * zero in case the copy should be allowed. + */ +static int generic_copy_file_checks(struct file *file_in, loff_t pos_in, + struct file *file_out, loff_t pos_out, + size_t *req_count, unsigned int flags) +{ + struct inode *inode_in = file_inode(file_in); + struct inode *inode_out = file_inode(file_out); + uint64_t count = *req_count; + loff_t size_in; + int ret; + + ret = generic_file_rw_checks(file_in, file_out); + if (ret) + return ret; + + /* + * We allow some filesystems to handle cross sb copy, but passing + * a file of the wrong filesystem type to filesystem driver can result + * in an attempt to dereference the wrong type of ->private_data, so + * avoid doing that until we really have a good reason. + * + * nfs and cifs define several different file_system_type structures + * and several different sets of file_operations, but they all end up + * using the same ->copy_file_range() function pointer. + */ + if (flags & COPY_FILE_SPLICE) { + /* cross sb splice is allowed */ + } else if (file_out->f_op->copy_file_range) { + if (file_in->f_op->copy_file_range != + file_out->f_op->copy_file_range) + return -EXDEV; + } else if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb) { + return -EXDEV; + } + + /* Don't touch certain kinds of inodes */ + if (IS_IMMUTABLE(inode_out)) + return -EPERM; + + if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out)) + return -ETXTBSY; + + /* Ensure offsets don't wrap. */ + if (pos_in + count < pos_in || pos_out + count < pos_out) + return -EOVERFLOW; + + /* Shorten the copy to EOF */ + size_in = i_size_read(inode_in); + if (pos_in >= size_in) + count = 0; + else + count = min(count, size_in - (uint64_t)pos_in); + + ret = generic_write_check_limits(file_out, pos_out, &count); + if (ret) + return ret; + + /* Don't allow overlapped copying within the same file. */ + if (inode_in == inode_out && + pos_out + count > pos_in && + pos_out < pos_in + count) + return -EINVAL; + + *req_count = count; + return 0; +} + +/* + * copy_file_range() differs from regular file read and write in that it + * specifically allows return partial success. When it does so is up to + * the copy_file_range method. + */ +ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, + struct file *file_out, loff_t pos_out, + size_t len, unsigned int flags) +{ + ssize_t ret; + bool splice = flags & COPY_FILE_SPLICE; + bool samesb = file_inode(file_in)->i_sb == file_inode(file_out)->i_sb; + + if (flags & ~COPY_FILE_SPLICE) + return -EINVAL; + + ret = generic_copy_file_checks(file_in, pos_in, file_out, pos_out, &len, + flags); + if (unlikely(ret)) + return ret; + + ret = rw_verify_area(READ, file_in, &pos_in, len); + if (unlikely(ret)) + return ret; + + ret = rw_verify_area(WRITE, file_out, &pos_out, len); + if (unlikely(ret)) + return ret; + + if (len == 0) + return 0; + + /* + * Make sure return value doesn't overflow in 32bit compat mode. Also + * limit the size for all cases except when calling ->copy_file_range(). + */ + if (splice || !file_out->f_op->copy_file_range || in_compat_syscall()) + len = min_t(size_t, MAX_RW_COUNT, len); + + file_start_write(file_out); + + /* + * Cloning is supported by more file systems, so we implement copy on + * same sb using clone, but for filesystems where both clone and copy + * are supported (e.g. nfs,cifs), we only call the copy method. + */ + if (!splice && file_out->f_op->copy_file_range) { + ret = file_out->f_op->copy_file_range(file_in, pos_in, + file_out, pos_out, + len, flags); + } else if (!splice && file_in->f_op->remap_file_range && samesb) { + ret = file_in->f_op->remap_file_range(file_in, pos_in, + file_out, pos_out, len, REMAP_FILE_CAN_SHORTEN); + /* fallback to splice */ + if (ret <= 0) + splice = true; + } else if (samesb) { + /* Fallback to splice for same sb copy for backward compat */ + splice = true; + } + + file_end_write(file_out); + + if (!splice) + goto done; + + /* + * We can get here for same sb copy of filesystems that do not implement + * ->copy_file_range() in case filesystem does not support clone or in + * case filesystem supports clone but rejected the clone request (e.g. + * because it was not block aligned). + * + * In both cases, fall back to kernel copy so we are able to maintain a + * consistent story about which filesystems support copy_file_range() + * and which filesystems do not, that will allow userspace tools to + * make consistent desicions w.r.t using copy_file_range(). + * + * We also get here if caller (e.g. nfsd) requested COPY_FILE_SPLICE + * for server-side-copy between any two sb. + * + * In any case, we call do_splice_direct() and not splice_file_range(), + * without file_start_write() held, to avoid possible deadlocks related + * to splicing from input file, while file_start_write() is held on + * the output file on a different sb. + */ + ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out, len, 0); +done: + if (ret > 0) { + fsnotify_access(file_in); + add_rchar(current, ret); + fsnotify_modify(file_out); + add_wchar(current, ret); + } + + inc_syscr(current); + inc_syscw(current); + + return ret; +} +EXPORT_SYMBOL(vfs_copy_file_range); + +SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in, + int, fd_out, loff_t __user *, off_out, + size_t, len, unsigned int, flags) +{ + loff_t pos_in; + loff_t pos_out; + ssize_t ret = -EBADF; + + CLASS(fd, f_in)(fd_in); + if (fd_empty(f_in)) + return -EBADF; + + CLASS(fd, f_out)(fd_out); + if (fd_empty(f_out)) + return -EBADF; + + if (off_in) { + if (copy_from_user(&pos_in, off_in, sizeof(loff_t))) + return -EFAULT; + } else { + pos_in = fd_file(f_in)->f_pos; + } + + if (off_out) { + if (copy_from_user(&pos_out, off_out, sizeof(loff_t))) + return -EFAULT; + } else { + pos_out = fd_file(f_out)->f_pos; + } + + if (flags != 0) + return -EINVAL; + + ret = vfs_copy_file_range(fd_file(f_in), pos_in, fd_file(f_out), pos_out, len, + flags); + if (ret > 0) { + pos_in += ret; + pos_out += ret; + + if (off_in) { + if (copy_to_user(off_in, &pos_in, sizeof(loff_t))) + ret = -EFAULT; + } else { + fd_file(f_in)->f_pos = pos_in; + } + + if (off_out) { + if (copy_to_user(off_out, &pos_out, sizeof(loff_t))) + ret = -EFAULT; + } else { + fd_file(f_out)->f_pos = pos_out; + } + } + return ret; +} + +/* + * Don't operate on ranges the page cache doesn't support, and don't exceed the + * LFS limits. If pos is under the limit it becomes a short access. If it + * exceeds the limit we return -EFBIG. + */ +int generic_write_check_limits(struct file *file, loff_t pos, loff_t *count) +{ + struct inode *inode = file->f_mapping->host; + loff_t max_size = inode->i_sb->s_maxbytes; + loff_t limit = rlimit(RLIMIT_FSIZE); + + if (limit != RLIM_INFINITY) { + if (pos >= limit) { + send_sig(SIGXFSZ, current, 0); + return -EFBIG; + } + *count = min(*count, limit - pos); + } + + if (!(file->f_flags & O_LARGEFILE)) + max_size = MAX_NON_LFS; + + if (unlikely(pos >= max_size)) + return -EFBIG; + + *count = min(*count, max_size - pos); + + return 0; +} +EXPORT_SYMBOL_GPL(generic_write_check_limits); + +/* Like generic_write_checks(), but takes size of write instead of iter. */ +int generic_write_checks_count(struct kiocb *iocb, loff_t *count) +{ + struct file *file = iocb->ki_filp; + struct inode *inode = file->f_mapping->host; + + if (IS_SWAPFILE(inode)) + return -ETXTBSY; + + if (!*count) + return 0; + + if (iocb->ki_flags & IOCB_APPEND) + iocb->ki_pos = i_size_read(inode); + + if ((iocb->ki_flags & IOCB_NOWAIT) && + !((iocb->ki_flags & IOCB_DIRECT) || + (file->f_op->fop_flags & FOP_BUFFER_WASYNC))) + return -EINVAL; + + return generic_write_check_limits(iocb->ki_filp, iocb->ki_pos, count); +} +EXPORT_SYMBOL(generic_write_checks_count); + +/* + * Performs necessary checks before doing a write + * + * Can adjust writing position or amount of bytes to write. + * Returns appropriate error code that caller should return or + * zero in case that write should be allowed. + */ +ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) +{ + loff_t count = iov_iter_count(from); + int ret; + + ret = generic_write_checks_count(iocb, &count); + if (ret) + return ret; + + iov_iter_truncate(from, count); + return iov_iter_count(from); +} +EXPORT_SYMBOL(generic_write_checks); + +/* + * Performs common checks before doing a file copy/clone + * from @file_in to @file_out. + */ +int generic_file_rw_checks(struct file *file_in, struct file *file_out) +{ + struct inode *inode_in = file_inode(file_in); + struct inode *inode_out = file_inode(file_out); + + /* Don't copy dirs, pipes, sockets... */ + if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) + return -EISDIR; + if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) + return -EINVAL; + + if (!(file_in->f_mode & FMODE_READ) || + !(file_out->f_mode & FMODE_WRITE) || + (file_out->f_flags & O_APPEND)) + return -EBADF; + + return 0; +} + +int generic_atomic_write_valid(struct kiocb *iocb, struct iov_iter *iter) +{ + size_t len = iov_iter_count(iter); + + if (!iter_is_ubuf(iter)) + return -EINVAL; + + if (!is_power_of_2(len)) + return -EINVAL; + + if (!IS_ALIGNED(iocb->ki_pos, len)) + return -EINVAL; + + if (!(iocb->ki_flags & IOCB_DIRECT)) + return -EOPNOTSUPP; + + return 0; +} +EXPORT_SYMBOL_GPL(generic_atomic_write_valid); -- cgit v1.3.1