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/affs/super.c | 684 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 684 insertions(+) create mode 100644 fs/affs/super.c (limited to 'fs/affs/super.c') diff --git a/fs/affs/super.c b/fs/affs/super.c new file mode 100644 index 000000000..ed8225b3c --- /dev/null +++ b/fs/affs/super.c @@ -0,0 +1,684 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/fs/affs/inode.c + * + * (c) 1996 Hans-Joachim Widmaier - Rewritten + * + * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem. + * + * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem. + * + * (C) 1991 Linus Torvalds - minix filesystem + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "affs.h" + +static int affs_statfs(struct dentry *dentry, struct kstatfs *buf); +static int affs_show_options(struct seq_file *m, struct dentry *root); + +static void +affs_commit_super(struct super_block *sb, int wait) +{ + struct affs_sb_info *sbi = AFFS_SB(sb); + struct buffer_head *bh = sbi->s_root_bh; + struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh); + + lock_buffer(bh); + affs_secs_to_datestamp(ktime_get_real_seconds(), &tail->disk_change); + affs_fix_checksum(sb, bh); + unlock_buffer(bh); + + mark_buffer_dirty(bh); + if (wait) + sync_dirty_buffer(bh); +} + +static void +affs_put_super(struct super_block *sb) +{ + struct affs_sb_info *sbi = AFFS_SB(sb); + pr_debug("%s()\n", __func__); + + cancel_delayed_work_sync(&sbi->sb_work); +} + +static int +affs_sync_fs(struct super_block *sb, int wait) +{ + affs_commit_super(sb, wait); + return 0; +} + +static void flush_superblock(struct work_struct *work) +{ + struct affs_sb_info *sbi; + struct super_block *sb; + + sbi = container_of(work, struct affs_sb_info, sb_work.work); + sb = sbi->sb; + + spin_lock(&sbi->work_lock); + sbi->work_queued = 0; + spin_unlock(&sbi->work_lock); + + affs_commit_super(sb, 1); +} + +void affs_mark_sb_dirty(struct super_block *sb) +{ + struct affs_sb_info *sbi = AFFS_SB(sb); + unsigned long delay; + + if (sb_rdonly(sb)) + return; + + spin_lock(&sbi->work_lock); + if (!sbi->work_queued) { + delay = msecs_to_jiffies(dirty_writeback_interval * 10); + queue_delayed_work(system_dfl_long_wq, &sbi->sb_work, delay); + sbi->work_queued = 1; + } + spin_unlock(&sbi->work_lock); +} + +static struct kmem_cache * affs_inode_cachep; + +static struct inode *affs_alloc_inode(struct super_block *sb) +{ + struct affs_inode_info *i; + + i = alloc_inode_sb(sb, affs_inode_cachep, GFP_KERNEL); + if (!i) + return NULL; + + inode_set_iversion(&i->vfs_inode, 1); + i->i_lc = NULL; + i->i_ext_bh = NULL; + i->i_pa_cnt = 0; + + return &i->vfs_inode; +} + +static void affs_free_inode(struct inode *inode) +{ + kmem_cache_free(affs_inode_cachep, AFFS_I(inode)); +} + +static void init_once(void *foo) +{ + struct affs_inode_info *ei = (struct affs_inode_info *) foo; + + mutex_init(&ei->i_link_lock); + mutex_init(&ei->i_ext_lock); + inode_init_once(&ei->vfs_inode); +} + +static int __init init_inodecache(void) +{ + affs_inode_cachep = kmem_cache_create("affs_inode_cache", + sizeof(struct affs_inode_info), + 0, (SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT), + init_once); + if (affs_inode_cachep == NULL) + return -ENOMEM; + return 0; +} + +static void destroy_inodecache(void) +{ + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); + kmem_cache_destroy(affs_inode_cachep); +} + +static const struct super_operations affs_sops = { + .alloc_inode = affs_alloc_inode, + .free_inode = affs_free_inode, + .write_inode = affs_write_inode, + .evict_inode = affs_evict_inode, + .put_super = affs_put_super, + .sync_fs = affs_sync_fs, + .statfs = affs_statfs, + .show_options = affs_show_options, +}; + +enum { + Opt_bs, Opt_mode, Opt_mufs, Opt_notruncate, Opt_prefix, Opt_protect, + Opt_reserved, Opt_root, Opt_setgid, Opt_setuid, + Opt_verbose, Opt_volume, Opt_ignore, +}; + +struct affs_context { + kuid_t uid; /* uid to override */ + kgid_t gid; /* gid to override */ + unsigned int mode; /* mode to override */ + unsigned int reserved; /* Number of reserved blocks */ + int root_block; /* FFS root block number */ + int blocksize; /* Initial device blksize */ + char *prefix; /* Prefix for volumes and assigns */ + char volume[32]; /* Vol. prefix for absolute symlinks */ + unsigned long mount_flags; /* Options */ +}; + +static const struct fs_parameter_spec affs_param_spec[] = { + fsparam_u32 ("bs", Opt_bs), + fsparam_u32oct ("mode", Opt_mode), + fsparam_flag ("mufs", Opt_mufs), + fsparam_flag ("nofilenametruncate", Opt_notruncate), + fsparam_string ("prefix", Opt_prefix), + fsparam_flag ("protect", Opt_protect), + fsparam_u32 ("reserved", Opt_reserved), + fsparam_u32 ("root", Opt_root), + fsparam_gid ("setgid", Opt_setgid), + fsparam_uid ("setuid", Opt_setuid), + fsparam_flag ("verbose", Opt_verbose), + fsparam_string ("volume", Opt_volume), + fsparam_flag ("grpquota", Opt_ignore), + fsparam_flag ("noquota", Opt_ignore), + fsparam_flag ("quota", Opt_ignore), + fsparam_flag ("usrquota", Opt_ignore), + {}, +}; + +static int affs_parse_param(struct fs_context *fc, struct fs_parameter *param) +{ + struct affs_context *ctx = fc->fs_private; + struct fs_parse_result result; + int n; + int opt; + + opt = fs_parse(fc, affs_param_spec, param, &result); + if (opt < 0) + return opt; + + switch (opt) { + case Opt_bs: + n = result.uint_32; + if (n != 512 && n != 1024 && n != 2048 + && n != 4096) { + pr_warn("Invalid blocksize (512, 1024, 2048, 4096 allowed)\n"); + return -EINVAL; + } + ctx->blocksize = n; + break; + case Opt_mode: + ctx->mode = result.uint_32 & 0777; + affs_set_opt(ctx->mount_flags, SF_SETMODE); + break; + case Opt_mufs: + affs_set_opt(ctx->mount_flags, SF_MUFS); + break; + case Opt_notruncate: + affs_set_opt(ctx->mount_flags, SF_NO_TRUNCATE); + break; + case Opt_prefix: + kfree(ctx->prefix); + ctx->prefix = param->string; + param->string = NULL; + affs_set_opt(ctx->mount_flags, SF_PREFIX); + break; + case Opt_protect: + affs_set_opt(ctx->mount_flags, SF_IMMUTABLE); + break; + case Opt_reserved: + ctx->reserved = result.uint_32; + break; + case Opt_root: + ctx->root_block = result.uint_32; + break; + case Opt_setgid: + ctx->gid = result.gid; + affs_set_opt(ctx->mount_flags, SF_SETGID); + break; + case Opt_setuid: + ctx->uid = result.uid; + affs_set_opt(ctx->mount_flags, SF_SETUID); + break; + case Opt_verbose: + affs_set_opt(ctx->mount_flags, SF_VERBOSE); + break; + case Opt_volume: + strscpy(ctx->volume, param->string, 32); + break; + case Opt_ignore: + /* Silently ignore the quota options */ + break; + default: + return -EINVAL; + } + return 0; +} + +static int affs_show_options(struct seq_file *m, struct dentry *root) +{ + struct super_block *sb = root->d_sb; + struct affs_sb_info *sbi = AFFS_SB(sb); + + if (sb->s_blocksize) + seq_printf(m, ",bs=%lu", sb->s_blocksize); + if (affs_test_opt(sbi->s_flags, SF_SETMODE)) + seq_printf(m, ",mode=%o", sbi->s_mode); + if (affs_test_opt(sbi->s_flags, SF_MUFS)) + seq_puts(m, ",mufs"); + if (affs_test_opt(sbi->s_flags, SF_NO_TRUNCATE)) + seq_puts(m, ",nofilenametruncate"); + if (affs_test_opt(sbi->s_flags, SF_PREFIX)) + seq_printf(m, ",prefix=%s", sbi->s_prefix); + if (affs_test_opt(sbi->s_flags, SF_IMMUTABLE)) + seq_puts(m, ",protect"); + if (sbi->s_reserved != 2) + seq_printf(m, ",reserved=%u", sbi->s_reserved); + if (sbi->s_root_block != (sbi->s_reserved + sbi->s_partition_size - 1) / 2) + seq_printf(m, ",root=%u", sbi->s_root_block); + if (affs_test_opt(sbi->s_flags, SF_SETGID)) + seq_printf(m, ",setgid=%u", + from_kgid_munged(&init_user_ns, sbi->s_gid)); + if (affs_test_opt(sbi->s_flags, SF_SETUID)) + seq_printf(m, ",setuid=%u", + from_kuid_munged(&init_user_ns, sbi->s_uid)); + if (affs_test_opt(sbi->s_flags, SF_VERBOSE)) + seq_puts(m, ",verbose"); + if (sbi->s_volume[0]) + seq_printf(m, ",volume=%s", sbi->s_volume); + return 0; +} + +/* This function definitely needs to be split up. Some fine day I'll + * hopefully have the guts to do so. Until then: sorry for the mess. + */ + +static int affs_fill_super(struct super_block *sb, struct fs_context *fc) +{ + struct affs_sb_info *sbi; + struct affs_context *ctx = fc->fs_private; + struct buffer_head *root_bh = NULL; + struct buffer_head *boot_bh; + struct inode *root_inode = NULL; + int silent = fc->sb_flags & SB_SILENT; + int size, blocksize; + u32 chksum; + int num_bm; + int i, j; + int tmp_flags; /* fix remount prototype... */ + u8 sig[4]; + int ret; + + sb->s_magic = AFFS_SUPER_MAGIC; + sb->s_op = &affs_sops; + sb->s_flags |= SB_NODIRATIME; + + sb->s_time_gran = NSEC_PER_SEC; + sb->s_time_min = sys_tz.tz_minuteswest * 60 + AFFS_EPOCH_DELTA; + sb->s_time_max = 86400LL * U32_MAX + 86400 + sb->s_time_min; + + sbi = kzalloc_obj(struct affs_sb_info); + if (!sbi) + return -ENOMEM; + + sb->s_fs_info = sbi; + sbi->sb = sb; + mutex_init(&sbi->s_bmlock); + spin_lock_init(&sbi->symlink_lock); + spin_lock_init(&sbi->work_lock); + INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock); + + sbi->s_flags = ctx->mount_flags; + sbi->s_mode = ctx->mode; + sbi->s_uid = ctx->uid; + sbi->s_gid = ctx->gid; + sbi->s_reserved = ctx->reserved; + sbi->s_prefix = ctx->prefix; + ctx->prefix = NULL; + memcpy(sbi->s_volume, ctx->volume, 32); + + /* N.B. after this point s_prefix must be released */ + + /* Get the size of the device in 512-byte blocks. + * If we later see that the partition uses bigger + * blocks, we will have to change it. + */ + + size = bdev_nr_sectors(sb->s_bdev); + pr_debug("initial blocksize=%d, #blocks=%d\n", 512, size); + + if (!sb_set_blocksize(sb, PAGE_SIZE)) + return -EINVAL; + /* Try to find root block. Its location depends on the block size. */ + + i = bdev_logical_block_size(sb->s_bdev); + j = PAGE_SIZE; + blocksize = ctx->blocksize; + if (blocksize > 0) { + i = j = blocksize; + size = size / (blocksize / 512); + } + + for (blocksize = i; blocksize <= j; blocksize <<= 1, size >>= 1) { + sbi->s_root_block = ctx->root_block; + if (ctx->root_block < 0) + sbi->s_root_block = (ctx->reserved + size - 1) / 2; + pr_debug("setting blocksize to %d\n", blocksize); + if (!sb_set_blocksize(sb, blocksize)) + return -EINVAL; + sbi->s_partition_size = size; + + /* The root block location that was calculated above is not + * correct if the partition size is an odd number of 512- + * byte blocks, which will be rounded down to a number of + * 1024-byte blocks, and if there were an even number of + * reserved blocks. Ideally, all partition checkers should + * report the real number of blocks of the real blocksize, + * but since this just cannot be done, we have to try to + * find the root block anyways. In the above case, it is one + * block behind the calculated one. So we check this one, too. + */ + for (num_bm = 0; num_bm < 2; num_bm++) { + pr_debug("Dev %s, trying root=%u, bs=%d, " + "size=%d, reserved=%d\n", + sb->s_id, + sbi->s_root_block + num_bm, + ctx->blocksize, size, ctx->reserved); + root_bh = affs_bread(sb, sbi->s_root_block + num_bm); + if (!root_bh) + continue; + if (!affs_checksum_block(sb, root_bh) && + be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT && + be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) { + sbi->s_hashsize = blocksize / 4 - 56; + sbi->s_root_block += num_bm; + goto got_root; + } + affs_brelse(root_bh); + root_bh = NULL; + } + } + if (!silent) + pr_err("No valid root block on device %s\n", sb->s_id); + return -EINVAL; + + /* N.B. after this point bh must be released */ +got_root: + /* Keep super block in cache */ + sbi->s_root_bh = root_bh; + ctx->root_block = sbi->s_root_block; + + /* Find out which kind of FS we have */ + boot_bh = sb_bread(sb, 0); + if (!boot_bh) { + pr_err("Cannot read boot block\n"); + return -EINVAL; + } + memcpy(sig, boot_bh->b_data, 4); + brelse(boot_bh); + chksum = be32_to_cpu(*(__be32 *)sig); + + /* Dircache filesystems are compatible with non-dircache ones + * when reading. As long as they aren't supported, writing is + * not recommended. + */ + if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS + || chksum == MUFS_DCOFS) && !sb_rdonly(sb)) { + pr_notice("Dircache FS - mounting %s read only\n", sb->s_id); + sb->s_flags |= SB_RDONLY; + } + switch (chksum) { + case MUFS_FS: + case MUFS_INTLFFS: + case MUFS_DCFFS: + affs_set_opt(sbi->s_flags, SF_MUFS); + fallthrough; + case FS_INTLFFS: + case FS_DCFFS: + affs_set_opt(sbi->s_flags, SF_INTL); + break; + case MUFS_FFS: + affs_set_opt(sbi->s_flags, SF_MUFS); + break; + case FS_FFS: + break; + case MUFS_OFS: + affs_set_opt(sbi->s_flags, SF_MUFS); + fallthrough; + case FS_OFS: + affs_set_opt(sbi->s_flags, SF_OFS); + sb->s_flags |= SB_NOEXEC; + break; + case MUFS_DCOFS: + case MUFS_INTLOFS: + affs_set_opt(sbi->s_flags, SF_MUFS); + fallthrough; + case FS_DCOFS: + case FS_INTLOFS: + affs_set_opt(sbi->s_flags, SF_INTL); + affs_set_opt(sbi->s_flags, SF_OFS); + sb->s_flags |= SB_NOEXEC; + break; + default: + pr_err("Unknown filesystem on device %s: %08X\n", + sb->s_id, chksum); + return -EINVAL; + } + + if (affs_test_opt(ctx->mount_flags, SF_VERBOSE)) { + u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0]; + pr_notice("Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n", + len > 31 ? 31 : len, + AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1, + sig, sig[3] + '0', blocksize); + } + + sb->s_flags |= SB_NODEV | SB_NOSUID; + + sbi->s_data_blksize = sb->s_blocksize; + if (affs_test_opt(sbi->s_flags, SF_OFS)) + sbi->s_data_blksize -= 24; + + tmp_flags = sb->s_flags; + ret = affs_init_bitmap(sb, &tmp_flags); + if (ret) + return ret; + sb->s_flags = tmp_flags; + + /* set up enough so that it can read an inode */ + + root_inode = affs_iget(sb, ctx->root_block); + if (IS_ERR(root_inode)) + return PTR_ERR(root_inode); + + if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL)) + set_default_d_op(sb, &affs_intl_dentry_operations); + else + set_default_d_op(sb, &affs_dentry_operations); + + sb->s_root = d_make_root(root_inode); + if (!sb->s_root) { + pr_err("AFFS: Get root inode failed\n"); + return -ENOMEM; + } + + sb->s_export_op = &affs_export_ops; + pr_debug("s_flags=%lX\n", sb->s_flags); + return 0; +} + +static int affs_reconfigure(struct fs_context *fc) +{ + struct super_block *sb = fc->root->d_sb; + struct affs_context *ctx = fc->fs_private; + struct affs_sb_info *sbi = AFFS_SB(sb); + int res = 0; + + sync_filesystem(sb); + fc->sb_flags |= SB_NODIRATIME; + + flush_delayed_work(&sbi->sb_work); + + /* + * NB: Historically, only mount_flags, mode, uid, gic, prefix, + * and volume are accepted during remount. + */ + sbi->s_flags = ctx->mount_flags; + sbi->s_mode = ctx->mode; + sbi->s_uid = ctx->uid; + sbi->s_gid = ctx->gid; + /* protect against readers */ + spin_lock(&sbi->symlink_lock); + if (ctx->prefix) { + kfree(sbi->s_prefix); + sbi->s_prefix = ctx->prefix; + ctx->prefix = NULL; + } + memcpy(sbi->s_volume, ctx->volume, 32); + spin_unlock(&sbi->symlink_lock); + + if ((bool)(fc->sb_flags & SB_RDONLY) == sb_rdonly(sb)) + return 0; + + if (fc->sb_flags & SB_RDONLY) + affs_free_bitmap(sb); + else + res = affs_init_bitmap(sb, &fc->sb_flags); + + return res; +} + +static int +affs_statfs(struct dentry *dentry, struct kstatfs *buf) +{ + struct super_block *sb = dentry->d_sb; + int free; + u64 id = huge_encode_dev(sb->s_bdev->bd_dev); + + pr_debug("%s() partsize=%d, reserved=%d\n", + __func__, AFFS_SB(sb)->s_partition_size, + AFFS_SB(sb)->s_reserved); + + free = affs_count_free_blocks(sb); + buf->f_type = AFFS_SUPER_MAGIC; + buf->f_bsize = sb->s_blocksize; + buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved; + buf->f_bfree = free; + buf->f_bavail = free; + buf->f_fsid = u64_to_fsid(id); + buf->f_namelen = AFFSNAMEMAX; + return 0; +} + +static int affs_get_tree(struct fs_context *fc) +{ + return get_tree_bdev(fc, affs_fill_super); +} + +static void affs_kill_sb(struct super_block *sb) +{ + struct affs_sb_info *sbi = AFFS_SB(sb); + kill_block_super(sb); + if (sbi) { + affs_free_bitmap(sb); + affs_brelse(sbi->s_root_bh); + kfree(sbi->s_prefix); + mutex_destroy(&sbi->s_bmlock); + kfree_rcu(sbi, rcu); + } +} + +static void affs_free_fc(struct fs_context *fc) +{ + struct affs_context *ctx = fc->fs_private; + + kfree(ctx->prefix); + kfree(ctx); +} + +static const struct fs_context_operations affs_context_ops = { + .parse_param = affs_parse_param, + .get_tree = affs_get_tree, + .reconfigure = affs_reconfigure, + .free = affs_free_fc, +}; + +static int affs_init_fs_context(struct fs_context *fc) +{ + struct affs_context *ctx; + + ctx = kzalloc_obj(struct affs_context); + if (!ctx) + return -ENOMEM; + + if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) { + struct super_block *sb = fc->root->d_sb; + struct affs_sb_info *sbi = AFFS_SB(sb); + + /* + * NB: historically, no options other than volume were + * preserved across a remount unless they were explicitly + * passed in. + */ + memcpy(ctx->volume, sbi->s_volume, 32); + } else { + ctx->uid = current_uid(); + ctx->gid = current_gid(); + ctx->reserved = 2; + ctx->root_block = -1; + ctx->blocksize = -1; + ctx->volume[0] = ':'; + } + + fc->ops = &affs_context_ops; + fc->fs_private = ctx; + + return 0; +} + +static struct file_system_type affs_fs_type = { + .owner = THIS_MODULE, + .name = "affs", + .kill_sb = affs_kill_sb, + .fs_flags = FS_REQUIRES_DEV, + .init_fs_context = affs_init_fs_context, + .parameters = affs_param_spec, +}; +MODULE_ALIAS_FS("affs"); + +static int __init init_affs_fs(void) +{ + int err = init_inodecache(); + if (err) + goto out1; + err = register_filesystem(&affs_fs_type); + if (err) + goto out; + return 0; +out: + destroy_inodecache(); +out1: + return err; +} + +static void __exit exit_affs_fs(void) +{ + unregister_filesystem(&affs_fs_type); + destroy_inodecache(); +} + +MODULE_DESCRIPTION("Amiga filesystem support for Linux"); +MODULE_LICENSE("GPL"); + +module_init(init_affs_fs) +module_exit(exit_affs_fs) -- cgit v1.3.1