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b=lirMygngoPpV5nhRxhbH4z1mIy hlsDjmDWWyE6nUtfUVQPv47nC+/WrEZJr7nDeOysNbnSezFLSrDDz5zP8bgxXHSS5kNCubOa/03mx qCP5tuHeyL8zVsljBmH+7tJhHfniiILfb2Q5UvSweK9MHOqiSPNGlncGf4h7f4s+2zlKWvoxZmnsA isrL97owOKHiEc3waHW85Hf3xim29p6lbc1QKE1jzZcjx7VW8CjtUOPEBl28F6UTZnks+QcHRgcjb Vp4tB4PbayjOYppvwRLnPb96idjTfPVtjWV2z4VsQN+vLGJ3dFR9BViIoT8/dVE6I1CFNQgWaMU4g lT2qeQQg==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vLE4W-0000000GET4-3GuY; Tue, 18 Nov 2025 05:16:08 +0000 From: Al Viro To: linux-fsdevel@vger.kernel.org Cc: torvalds@linux-foundation.org, brauner@kernel.org, jack@suse.cz, raven@themaw.net, miklos@szeredi.hu, neil@brown.name, a.hindborg@kernel.org, linux-mm@kvack.org, linux-efi@vger.kernel.org, ocfs2-devel@lists.linux.dev, kees@kernel.org, rostedt@goodmis.org, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, paul@paul-moore.com, casey@schaufler-ca.com, linuxppc-dev@lists.ozlabs.org, john.johansen@canonical.com, selinux@vger.kernel.org, borntraeger@linux.ibm.com, bpf@vger.kernel.org, clm@meta.com Subject: [PATCH v4 34/54] selinuxfs: new helper for attaching files to tree Date: Tue, 18 Nov 2025 05:15:43 +0000 Message-ID: <20251118051604.3868588-35-viro@zeniv.linux.org.uk> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20251118051604.3868588-1-viro@zeniv.linux.org.uk> References: <20251118051604.3868588-1-viro@zeniv.linux.org.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 5ECDE180002 X-Stat-Signature: 5wxmaf4b5dmf55tqr6ywqa6de45tohuz X-Rspam-User: X-HE-Tag: 1763442974-296135 X-HE-Meta: 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 9JnFlmDj 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: allocating dentry after the inode has been set up reduces the amount of boilerplate - "attach this inode under that name and this parent or drop inode in case of failure" simplifies quite a few places. Acked-by: Paul Moore Reviewed-by: Stephen Smalley Tested-by: Stephen Smalley Signed-off-by: Al Viro --- security/selinux/selinuxfs.c | 160 +++++++++++++++-------------------- 1 file changed, 66 insertions(+), 94 deletions(-) diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index b39e919c27b1..f088776dbbd3 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -1197,6 +1197,25 @@ static struct inode *sel_make_inode(struct super_block *sb, umode_t mode) return ret; } +static struct dentry *sel_attach(struct dentry *parent, const char *name, + struct inode *inode) +{ + struct dentry *dentry = d_alloc_name(parent, name); + if (unlikely(!dentry)) { + iput(inode); + return ERR_PTR(-ENOMEM); + } + d_add(dentry, inode); + return dentry; +} + +static int sel_attach_file(struct dentry *parent, const char *name, + struct inode *inode) +{ + struct dentry *dentry = sel_attach(parent, name, inode); + return PTR_ERR_OR_ZERO(dentry); +} + static ssize_t sel_read_bool(struct file *filep, char __user *buf, size_t count, loff_t *ppos) { @@ -1356,8 +1375,7 @@ static int sel_make_bools(struct selinux_policy *newpolicy, struct dentry *bool_ *bool_num = num; *bool_pending_names = names; - for (i = 0; i < num; i++) { - struct dentry *dentry; + for (i = 0; !ret && i < num; i++) { struct inode *inode; struct inode_security_struct *isec; ssize_t len; @@ -1368,15 +1386,9 @@ static int sel_make_bools(struct selinux_policy *newpolicy, struct dentry *bool_ ret = -ENAMETOOLONG; break; } - dentry = d_alloc_name(bool_dir, names[i]); - if (!dentry) { - ret = -ENOMEM; - break; - } inode = sel_make_inode(bool_dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR); if (!inode) { - dput(dentry); ret = -ENOMEM; break; } @@ -1394,7 +1406,8 @@ static int sel_make_bools(struct selinux_policy *newpolicy, struct dentry *bool_ isec->initialized = LABEL_INITIALIZED; inode->i_fop = &sel_bool_ops; inode->i_ino = i|SEL_BOOL_INO_OFFSET; - d_add(dentry, inode); + + ret = sel_attach_file(bool_dir, names[i], inode); } out: free_page((unsigned long)page); @@ -1579,6 +1592,7 @@ static int sel_make_avc_files(struct dentry *dir) struct super_block *sb = dir->d_sb; struct selinux_fs_info *fsi = sb->s_fs_info; unsigned int i; + int err = 0; static const struct tree_descr files[] = { { "cache_threshold", &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR }, @@ -1588,26 +1602,20 @@ static int sel_make_avc_files(struct dentry *dir) #endif }; - for (i = 0; i < ARRAY_SIZE(files); i++) { + for (i = 0; !err && i < ARRAY_SIZE(files); i++) { struct inode *inode; - struct dentry *dentry; - - dentry = d_alloc_name(dir, files[i].name); - if (!dentry) - return -ENOMEM; inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode); - if (!inode) { - dput(dentry); + if (!inode) return -ENOMEM; - } inode->i_fop = files[i].ops; inode->i_ino = ++fsi->last_ino; - d_add(dentry, inode); + + err = sel_attach_file(dir, files[i].name, inode); } - return 0; + return err; } static int sel_make_ss_files(struct dentry *dir) @@ -1615,30 +1623,25 @@ static int sel_make_ss_files(struct dentry *dir) struct super_block *sb = dir->d_sb; struct selinux_fs_info *fsi = sb->s_fs_info; unsigned int i; + int err = 0; static const struct tree_descr files[] = { { "sidtab_hash_stats", &sel_sidtab_hash_stats_ops, S_IRUGO }, }; - for (i = 0; i < ARRAY_SIZE(files); i++) { + for (i = 0; !err && i < ARRAY_SIZE(files); i++) { struct inode *inode; - struct dentry *dentry; - - dentry = d_alloc_name(dir, files[i].name); - if (!dentry) - return -ENOMEM; inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode); - if (!inode) { - dput(dentry); + if (!inode) return -ENOMEM; - } inode->i_fop = files[i].ops; inode->i_ino = ++fsi->last_ino; - d_add(dentry, inode); + + err = sel_attach_file(dir, files[i].name, inode); } - return 0; + return err; } static ssize_t sel_read_initcon(struct file *file, char __user *buf, @@ -1666,30 +1669,25 @@ static const struct file_operations sel_initcon_ops = { static int sel_make_initcon_files(struct dentry *dir) { unsigned int i; + int err = 0; - for (i = 1; i <= SECINITSID_NUM; i++) { - struct inode *inode; - struct dentry *dentry; + for (i = 1; !err && i <= SECINITSID_NUM; i++) { const char *s = security_get_initial_sid_context(i); + struct inode *inode; if (!s) continue; - dentry = d_alloc_name(dir, s); - if (!dentry) - return -ENOMEM; inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO); - if (!inode) { - dput(dentry); + if (!inode) return -ENOMEM; - } inode->i_fop = &sel_initcon_ops; inode->i_ino = i|SEL_INITCON_INO_OFFSET; - d_add(dentry, inode); + err = sel_attach_file(dir, s, inode); } - return 0; + return err; } static inline unsigned long sel_class_to_ino(u16 class) @@ -1771,29 +1769,21 @@ static int sel_make_perm_files(struct selinux_policy *newpolicy, if (rc) return rc; - for (i = 0; i < nperms; i++) { + for (i = 0; !rc && i < nperms; i++) { struct inode *inode; - struct dentry *dentry; - rc = -ENOMEM; - dentry = d_alloc_name(dir, perms[i]); - if (!dentry) - goto out; - - rc = -ENOMEM; inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO); if (!inode) { - dput(dentry); - goto out; + rc = -ENOMEM; + break; } inode->i_fop = &sel_perm_ops; /* i+1 since perm values are 1-indexed */ inode->i_ino = sel_perm_to_ino(classvalue, i + 1); - d_add(dentry, inode); + + rc = sel_attach_file(dir, perms[i], inode); } - rc = 0; -out: for (i = 0; i < nperms; i++) kfree(perms[i]); kfree(perms); @@ -1808,20 +1798,18 @@ static int sel_make_class_dir_entries(struct selinux_policy *newpolicy, struct selinux_fs_info *fsi = sb->s_fs_info; struct dentry *dentry = NULL; struct inode *inode = NULL; - - dentry = d_alloc_name(dir, "index"); - if (!dentry) - return -ENOMEM; + int err; inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO); - if (!inode) { - dput(dentry); + if (!inode) return -ENOMEM; - } inode->i_fop = &sel_class_ops; inode->i_ino = sel_class_to_ino(index); - d_add(dentry, inode); + + err = sel_attach_file(dir, "index", inode); + if (err) + return err; dentry = sel_make_dir(dir, "perms", &fsi->last_class_ino); if (IS_ERR(dentry)) @@ -1873,58 +1861,47 @@ static int sel_make_policycap(struct dentry *dir) { struct super_block *sb = dir->d_sb; unsigned int iter; - struct dentry *dentry = NULL; struct inode *inode = NULL; + int err = 0; + + for (iter = 0; !err && iter <= POLICYDB_CAP_MAX; iter++) { + const char *name; - for (iter = 0; iter <= POLICYDB_CAP_MAX; iter++) { if (iter < ARRAY_SIZE(selinux_policycap_names)) - dentry = d_alloc_name(dir, - selinux_policycap_names[iter]); + name = selinux_policycap_names[iter]; else - dentry = d_alloc_name(dir, "unknown"); - - if (dentry == NULL) - return -ENOMEM; + name = "unknown"; inode = sel_make_inode(sb, S_IFREG | 0444); - if (inode == NULL) { - dput(dentry); + if (!inode) return -ENOMEM; - } inode->i_fop = &sel_policycap_ops; inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET; - d_add(dentry, inode); + err = sel_attach_file(dir, name, inode); } - return 0; + return err; } static struct dentry *sel_make_dir(struct dentry *dir, const char *name, unsigned long *ino) { - struct dentry *dentry = d_alloc_name(dir, name); struct inode *inode; - if (!dentry) - return ERR_PTR(-ENOMEM); - inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO); - if (!inode) { - dput(dentry); + if (!inode) return ERR_PTR(-ENOMEM); - } inode->i_op = &simple_dir_inode_operations; inode->i_fop = &simple_dir_operations; inode->i_ino = ++(*ino); /* directory inodes start off with i_nlink == 2 (for "." entry) */ inc_nlink(inode); - d_add(dentry, inode); /* bump link count on parent directory, too */ inc_nlink(d_inode(dir)); - return dentry; + return sel_attach(dir, name, inode); } static int reject_all(struct mnt_idmap *idmap, struct inode *inode, int mask) @@ -2012,17 +1989,10 @@ static int sel_fill_super(struct super_block *sb, struct fs_context *fc) goto err; } - ret = -ENOMEM; - dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME); - if (!dentry) - goto err; - ret = -ENOMEM; inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO); - if (!inode) { - dput(dentry); + if (!inode) goto err; - } inode->i_ino = ++fsi->last_ino; isec = selinux_inode(inode); @@ -2031,7 +2001,9 @@ static int sel_fill_super(struct super_block *sb, struct fs_context *fc) isec->initialized = LABEL_INITIALIZED; init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3)); - d_add(dentry, inode); + ret = sel_attach_file(sb->s_root, NULL_FILE_NAME, inode); + if (ret) + goto err; dentry = sel_make_dir(sb->s_root, "avc", &fsi->last_ino); if (IS_ERR(dentry)) { -- 2.47.3