From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- fs/vboxsf/utils.c | 599 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 599 insertions(+) create mode 100644 fs/vboxsf/utils.c (limited to 'fs/vboxsf/utils.c') diff --git a/fs/vboxsf/utils.c b/fs/vboxsf/utils.c new file mode 100644 index 000000000..298bfc932 --- /dev/null +++ b/fs/vboxsf/utils.c @@ -0,0 +1,599 @@ +// SPDX-License-Identifier: MIT +/* + * VirtualBox Guest Shared Folders support: Utility functions. + * Mainly conversion from/to VirtualBox/Linux data structures. + * + * Copyright (C) 2006-2018 Oracle Corporation + */ + +#include +#include +#include +#include +#include +#include +#include "vfsmod.h" + +struct inode *vboxsf_new_inode(struct super_block *sb) +{ + struct vboxsf_sbi *sbi = VBOXSF_SBI(sb); + struct inode *inode; + unsigned long flags; + int cursor, ret; + u32 gen; + + inode = new_inode(sb); + if (!inode) + return ERR_PTR(-ENOMEM); + + idr_preload(GFP_KERNEL); + spin_lock_irqsave(&sbi->ino_idr_lock, flags); + cursor = idr_get_cursor(&sbi->ino_idr); + ret = idr_alloc_cyclic(&sbi->ino_idr, inode, 1, 0, GFP_ATOMIC); + if (ret >= 0 && ret < cursor) + sbi->next_generation++; + gen = sbi->next_generation; + spin_unlock_irqrestore(&sbi->ino_idr_lock, flags); + idr_preload_end(); + + if (ret < 0) { + iput(inode); + return ERR_PTR(ret); + } + + inode->i_ino = ret; + inode->i_generation = gen; + return inode; +} + +/* set [inode] attributes based on [info], uid/gid based on [sbi] */ +int vboxsf_init_inode(struct vboxsf_sbi *sbi, struct inode *inode, + const struct shfl_fsobjinfo *info, bool reinit) +{ + const struct shfl_fsobjattr *attr; + s64 allocated; + umode_t mode; + + attr = &info->attr; + +#define mode_set(r) ((attr->mode & (SHFL_UNIX_##r)) ? (S_##r) : 0) + + mode = mode_set(IRUSR); + mode |= mode_set(IWUSR); + mode |= mode_set(IXUSR); + + mode |= mode_set(IRGRP); + mode |= mode_set(IWGRP); + mode |= mode_set(IXGRP); + + mode |= mode_set(IROTH); + mode |= mode_set(IWOTH); + mode |= mode_set(IXOTH); + +#undef mode_set + + /* We use the host-side values for these */ + inode->i_flags |= S_NOATIME | S_NOCMTIME; + inode->i_mapping->a_ops = &vboxsf_reg_aops; + + if (SHFL_IS_DIRECTORY(attr->mode)) { + if (sbi->o.dmode_set) + mode = sbi->o.dmode; + mode &= ~sbi->o.dmask; + mode |= S_IFDIR; + if (!reinit) { + inode->i_op = &vboxsf_dir_iops; + inode->i_fop = &vboxsf_dir_fops; + /* + * XXX: this probably should be set to the number of entries + * in the directory plus two (. ..) + */ + set_nlink(inode, 1); + } else if (!S_ISDIR(inode->i_mode)) + return -ESTALE; + inode->i_mode = mode; + } else if (SHFL_IS_SYMLINK(attr->mode)) { + if (sbi->o.fmode_set) + mode = sbi->o.fmode; + mode &= ~sbi->o.fmask; + mode |= S_IFLNK; + if (!reinit) { + inode->i_op = &vboxsf_lnk_iops; + set_nlink(inode, 1); + } else if (!S_ISLNK(inode->i_mode)) + return -ESTALE; + inode->i_mode = mode; + } else { + if (sbi->o.fmode_set) + mode = sbi->o.fmode; + mode &= ~sbi->o.fmask; + mode |= S_IFREG; + if (!reinit) { + inode->i_op = &vboxsf_reg_iops; + inode->i_fop = &vboxsf_reg_fops; + set_nlink(inode, 1); + } else if (!S_ISREG(inode->i_mode)) + return -ESTALE; + inode->i_mode = mode; + } + + inode->i_uid = sbi->o.uid; + inode->i_gid = sbi->o.gid; + + inode->i_size = info->size; + inode->i_blkbits = 12; + /* i_blocks always in units of 512 bytes! */ + allocated = info->allocated + 511; + do_div(allocated, 512); + inode->i_blocks = allocated; + + inode_set_atime_to_ts(inode, + ns_to_timespec64(info->access_time.ns_relative_to_unix_epoch)); + inode_set_ctime_to_ts(inode, + ns_to_timespec64(info->change_time.ns_relative_to_unix_epoch)); + inode_set_mtime_to_ts(inode, + ns_to_timespec64(info->modification_time.ns_relative_to_unix_epoch)); + return 0; +} + +int vboxsf_create_at_dentry(struct dentry *dentry, + struct shfl_createparms *params) +{ + struct vboxsf_sbi *sbi = VBOXSF_SBI(dentry->d_sb); + struct shfl_string *path; + int err; + + path = vboxsf_path_from_dentry(sbi, dentry); + if (IS_ERR(path)) + return PTR_ERR(path); + + err = vboxsf_create(sbi->root, path, params); + __putname(path); + + return err; +} + +int vboxsf_stat(struct vboxsf_sbi *sbi, struct shfl_string *path, + struct shfl_fsobjinfo *info) +{ + struct shfl_createparms params = {}; + int err; + + params.handle = SHFL_HANDLE_NIL; + params.create_flags = SHFL_CF_LOOKUP | SHFL_CF_ACT_FAIL_IF_NEW; + + err = vboxsf_create(sbi->root, path, ¶ms); + if (err) + return err; + + if (params.result != SHFL_FILE_EXISTS) + return -ENOENT; + + if (info) + *info = params.info; + + return 0; +} + +int vboxsf_stat_dentry(struct dentry *dentry, struct shfl_fsobjinfo *info) +{ + struct vboxsf_sbi *sbi = VBOXSF_SBI(dentry->d_sb); + struct shfl_string *path; + int err; + + path = vboxsf_path_from_dentry(sbi, dentry); + if (IS_ERR(path)) + return PTR_ERR(path); + + err = vboxsf_stat(sbi, path, info); + __putname(path); + return err; +} + +int vboxsf_inode_revalidate(struct dentry *dentry) +{ + struct vboxsf_sbi *sbi; + struct vboxsf_inode *sf_i; + struct shfl_fsobjinfo info; + struct timespec64 mtime, prev_mtime; + struct inode *inode; + int err; + + if (!dentry || !d_really_is_positive(dentry)) + return -EINVAL; + + inode = d_inode(dentry); + prev_mtime = inode_get_mtime(inode); + sf_i = VBOXSF_I(inode); + sbi = VBOXSF_SBI(dentry->d_sb); + if (!sf_i->force_restat) { + if (time_before(jiffies, dentry->d_time + sbi->o.ttl)) + return 0; + } + + err = vboxsf_stat_dentry(dentry, &info); + if (err) + return err; + + dentry->d_time = jiffies; + sf_i->force_restat = 0; + err = vboxsf_init_inode(sbi, inode, &info, true); + if (err) + return err; + + /* + * If the file was changed on the host side we need to invalidate the + * page-cache for it. Note this also gets triggered by our own writes, + * this is unavoidable. + */ + mtime = inode_get_mtime(inode); + if (timespec64_compare(&mtime, &prev_mtime) > 0) + invalidate_inode_pages2(inode->i_mapping); + + return 0; +} + +int vboxsf_getattr(struct mnt_idmap *idmap, const struct path *path, + struct kstat *kstat, u32 request_mask, unsigned int flags) +{ + int err; + struct dentry *dentry = path->dentry; + struct inode *inode = d_inode(dentry); + struct vboxsf_inode *sf_i = VBOXSF_I(inode); + + switch (flags & AT_STATX_SYNC_TYPE) { + case AT_STATX_DONT_SYNC: + err = 0; + break; + case AT_STATX_FORCE_SYNC: + sf_i->force_restat = 1; + fallthrough; + default: + err = vboxsf_inode_revalidate(dentry); + } + if (err) + return err; + + generic_fillattr(&nop_mnt_idmap, request_mask, d_inode(dentry), kstat); + return 0; +} + +int vboxsf_setattr(struct mnt_idmap *idmap, struct dentry *dentry, + struct iattr *iattr) +{ + struct vboxsf_inode *sf_i = VBOXSF_I(d_inode(dentry)); + struct vboxsf_sbi *sbi = VBOXSF_SBI(dentry->d_sb); + struct shfl_createparms params = {}; + struct shfl_fsobjinfo info = {}; + u32 buf_len; + int err; + + params.handle = SHFL_HANDLE_NIL; + params.create_flags = SHFL_CF_ACT_OPEN_IF_EXISTS | + SHFL_CF_ACT_FAIL_IF_NEW | + SHFL_CF_ACCESS_ATTR_WRITE; + + /* this is at least required for Posix hosts */ + if (iattr->ia_valid & ATTR_SIZE) + params.create_flags |= SHFL_CF_ACCESS_WRITE; + + err = vboxsf_create_at_dentry(dentry, ¶ms); + if (err || params.result != SHFL_FILE_EXISTS) + return err ? err : -ENOENT; + +#define mode_set(r) ((iattr->ia_mode & (S_##r)) ? SHFL_UNIX_##r : 0) + + /* + * Setting the file size and setting the other attributes has to + * be handled separately. + */ + if (iattr->ia_valid & (ATTR_MODE | ATTR_ATIME | ATTR_MTIME)) { + if (iattr->ia_valid & ATTR_MODE) { + info.attr.mode = mode_set(IRUSR); + info.attr.mode |= mode_set(IWUSR); + info.attr.mode |= mode_set(IXUSR); + info.attr.mode |= mode_set(IRGRP); + info.attr.mode |= mode_set(IWGRP); + info.attr.mode |= mode_set(IXGRP); + info.attr.mode |= mode_set(IROTH); + info.attr.mode |= mode_set(IWOTH); + info.attr.mode |= mode_set(IXOTH); + + if (iattr->ia_mode & S_IFDIR) + info.attr.mode |= SHFL_TYPE_DIRECTORY; + else + info.attr.mode |= SHFL_TYPE_FILE; + } + + if (iattr->ia_valid & ATTR_ATIME) + info.access_time.ns_relative_to_unix_epoch = + timespec64_to_ns(&iattr->ia_atime); + + if (iattr->ia_valid & ATTR_MTIME) + info.modification_time.ns_relative_to_unix_epoch = + timespec64_to_ns(&iattr->ia_mtime); + + /* + * Ignore ctime (inode change time) as it can't be set + * from userland anyway. + */ + + buf_len = sizeof(info); + err = vboxsf_fsinfo(sbi->root, params.handle, + SHFL_INFO_SET | SHFL_INFO_FILE, &buf_len, + &info); + if (err) { + vboxsf_close(sbi->root, params.handle); + return err; + } + + /* the host may have given us different attr then requested */ + sf_i->force_restat = 1; + } + +#undef mode_set + + if (iattr->ia_valid & ATTR_SIZE) { + memset(&info, 0, sizeof(info)); + info.size = iattr->ia_size; + buf_len = sizeof(info); + err = vboxsf_fsinfo(sbi->root, params.handle, + SHFL_INFO_SET | SHFL_INFO_SIZE, &buf_len, + &info); + if (err) { + vboxsf_close(sbi->root, params.handle); + return err; + } + + /* the host may have given us different attr then requested */ + sf_i->force_restat = 1; + } + + vboxsf_close(sbi->root, params.handle); + + /* Update the inode with what the host has actually given us. */ + if (sf_i->force_restat) + vboxsf_inode_revalidate(dentry); + + return 0; +} + +/* + * [dentry] contains string encoded in coding system that corresponds + * to [sbi]->nls, we must convert it to UTF8 here. + * Returns a shfl_string allocated through __getname (must be freed using + * __putname), or an ERR_PTR on error. + */ +struct shfl_string *vboxsf_path_from_dentry(struct vboxsf_sbi *sbi, + struct dentry *dentry) +{ + struct shfl_string *shfl_path; + int path_len, out_len, nb; + char *buf, *path; + wchar_t uni; + u8 *out; + + buf = __getname(); + if (!buf) + return ERR_PTR(-ENOMEM); + + path = dentry_path_raw(dentry, buf, PATH_MAX); + if (IS_ERR(path)) { + __putname(buf); + return ERR_CAST(path); + } + path_len = strlen(path); + + if (sbi->nls) { + shfl_path = __getname(); + if (!shfl_path) { + __putname(buf); + return ERR_PTR(-ENOMEM); + } + + out = shfl_path->string.utf8; + out_len = PATH_MAX - SHFLSTRING_HEADER_SIZE - 1; + + while (path_len) { + nb = sbi->nls->char2uni(path, path_len, &uni); + if (nb < 0) { + __putname(shfl_path); + __putname(buf); + return ERR_PTR(-EINVAL); + } + path += nb; + path_len -= nb; + + nb = utf32_to_utf8(uni, out, out_len); + if (nb < 0) { + __putname(shfl_path); + __putname(buf); + return ERR_PTR(-ENAMETOOLONG); + } + out += nb; + out_len -= nb; + } + *out = 0; + shfl_path->length = out - shfl_path->string.utf8; + shfl_path->size = shfl_path->length + 1; + __putname(buf); + } else { + if ((SHFLSTRING_HEADER_SIZE + path_len + 1) > PATH_MAX) { + __putname(buf); + return ERR_PTR(-ENAMETOOLONG); + } + /* + * dentry_path stores the name at the end of buf, but the + * shfl_string string we return must be properly aligned. + */ + shfl_path = (struct shfl_string *)buf; + memmove(shfl_path->string.utf8, path, path_len); + shfl_path->string.utf8[path_len] = 0; + shfl_path->length = path_len; + shfl_path->size = path_len + 1; + } + + return shfl_path; +} + +int vboxsf_nlscpy(struct vboxsf_sbi *sbi, char *name, size_t name_bound_len, + const unsigned char *utf8_name, size_t utf8_len) +{ + const char *in; + char *out; + size_t out_bound_len; + size_t in_bound_len; + + in = utf8_name; + in_bound_len = utf8_len; + + out = name; + /* Reserve space for terminating 0 */ + out_bound_len = name_bound_len - 1; + + while (in_bound_len) { + int nb; + unicode_t uni; + + nb = utf8_to_utf32(in, in_bound_len, &uni); + if (nb < 0) + return -EINVAL; + + in += nb; + in_bound_len -= nb; + + nb = sbi->nls->uni2char(uni, out, out_bound_len); + if (nb < 0) + return nb; + + out += nb; + out_bound_len -= nb; + } + + *out = 0; + + return 0; +} + +static struct vboxsf_dir_buf *vboxsf_dir_buf_alloc(struct list_head *list) +{ + struct vboxsf_dir_buf *b; + + b = kmalloc_obj(*b); + if (!b) + return NULL; + + b->buf = kmalloc(DIR_BUFFER_SIZE, GFP_KERNEL); + if (!b->buf) { + kfree(b); + return NULL; + } + + b->entries = 0; + b->used = 0; + b->free = DIR_BUFFER_SIZE; + list_add(&b->head, list); + + return b; +} + +static void vboxsf_dir_buf_free(struct vboxsf_dir_buf *b) +{ + list_del(&b->head); + kfree(b->buf); + kfree(b); +} + +struct vboxsf_dir_info *vboxsf_dir_info_alloc(void) +{ + struct vboxsf_dir_info *p; + + p = kmalloc_obj(*p); + if (!p) + return NULL; + + INIT_LIST_HEAD(&p->info_list); + return p; +} + +void vboxsf_dir_info_free(struct vboxsf_dir_info *p) +{ + struct list_head *list, *pos, *tmp; + + list = &p->info_list; + list_for_each_safe(pos, tmp, list) { + struct vboxsf_dir_buf *b; + + b = list_entry(pos, struct vboxsf_dir_buf, head); + vboxsf_dir_buf_free(b); + } + kfree(p); +} + +int vboxsf_dir_read_all(struct vboxsf_sbi *sbi, struct vboxsf_dir_info *sf_d, + u64 handle) +{ + struct vboxsf_dir_buf *b; + u32 entries, size; + int err = 0; + void *buf; + + /* vboxsf_dirinfo returns 1 on end of dir */ + while (err == 0) { + b = vboxsf_dir_buf_alloc(&sf_d->info_list); + if (!b) { + err = -ENOMEM; + break; + } + + buf = b->buf; + size = b->free; + + err = vboxsf_dirinfo(sbi->root, handle, NULL, 0, 0, + &size, buf, &entries); + if (err < 0) + break; + + b->entries += entries; + b->free -= size; + b->used += size; + } + + if (b && b->used == 0) + vboxsf_dir_buf_free(b); + + /* -EILSEQ means the host could not translate a filename, ignore */ + if (err > 0 || err == -EILSEQ) + err = 0; + + return err; +} + +int vboxsf_query_case_sensitive(struct vboxsf_sbi *sbi) +{ + struct shfl_volinfo volinfo = {}; + u32 buf_len; + int err; + + buf_len = sizeof(volinfo); + err = vboxsf_fsinfo(sbi->root, 0, SHFL_INFO_GET | SHFL_INFO_VOLUME, + &buf_len, &volinfo); + if (err) + return err; + if (buf_len < sizeof(volinfo)) + return 0; + + sbi->case_insensitive = !volinfo.properties.case_sensitive; + return 0; +} + +int vboxsf_fileattr_get(struct dentry *dentry, struct file_kattr *fa) +{ + struct vboxsf_sbi *sbi = VBOXSF_SBI(dentry->d_sb); + + if (sbi->case_insensitive) { + fa->fsx_xflags |= FS_XFLAG_CASEFOLD; + fa->flags |= FS_CASEFOLD_FL; + } + return 0; +} -- cgit v1.3.1