From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- fs/jffs2/acl.c | 312 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 312 insertions(+) create mode 100644 fs/jffs2/acl.c (limited to 'fs/jffs2/acl.c') diff --git a/fs/jffs2/acl.c b/fs/jffs2/acl.c new file mode 100644 index 000000000..f0f8a4f57 --- /dev/null +++ b/fs/jffs2/acl.c @@ -0,0 +1,312 @@ +/* + * JFFS2 -- Journalling Flash File System, Version 2. + * + * Copyright © 2006 NEC Corporation + * + * Created by KaiGai Kohei + * + * For licensing information, see the file 'LICENCE' in this directory. + * + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "nodelist.h" + +static size_t jffs2_acl_size(int count) +{ + if (count <= 4) { + return sizeof(struct jffs2_acl_header) + + count * sizeof(struct jffs2_acl_entry_short); + } else { + return sizeof(struct jffs2_acl_header) + + 4 * sizeof(struct jffs2_acl_entry_short) + + (count - 4) * sizeof(struct jffs2_acl_entry); + } +} + +static int jffs2_acl_count(size_t size) +{ + size_t s; + + size -= sizeof(struct jffs2_acl_header); + if (size < 4 * sizeof(struct jffs2_acl_entry_short)) { + if (size % sizeof(struct jffs2_acl_entry_short)) + return -1; + return size / sizeof(struct jffs2_acl_entry_short); + } else { + s = size - 4 * sizeof(struct jffs2_acl_entry_short); + if (s % sizeof(struct jffs2_acl_entry)) + return -1; + return s / sizeof(struct jffs2_acl_entry) + 4; + } +} + +static struct posix_acl *jffs2_acl_from_medium(void *value, size_t size) +{ + void *end = value + size; + struct jffs2_acl_header *header = value; + struct jffs2_acl_entry *entry; + struct posix_acl *acl; + uint32_t ver; + int i, count; + + if (!value) + return NULL; + if (size < sizeof(struct jffs2_acl_header)) + return ERR_PTR(-EINVAL); + ver = je32_to_cpu(header->a_version); + if (ver != JFFS2_ACL_VERSION) { + JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver); + return ERR_PTR(-EINVAL); + } + + value += sizeof(struct jffs2_acl_header); + count = jffs2_acl_count(size); + if (count < 0) + return ERR_PTR(-EINVAL); + if (count == 0) + return NULL; + + acl = posix_acl_alloc(count, GFP_KERNEL); + if (!acl) + return ERR_PTR(-ENOMEM); + + for (i=0; i < count; i++) { + entry = value; + if (value + sizeof(struct jffs2_acl_entry_short) > end) + goto fail; + acl->a_entries[i].e_tag = je16_to_cpu(entry->e_tag); + acl->a_entries[i].e_perm = je16_to_cpu(entry->e_perm); + switch (acl->a_entries[i].e_tag) { + case ACL_USER_OBJ: + case ACL_GROUP_OBJ: + case ACL_MASK: + case ACL_OTHER: + value += sizeof(struct jffs2_acl_entry_short); + break; + + case ACL_USER: + value += sizeof(struct jffs2_acl_entry); + if (value > end) + goto fail; + acl->a_entries[i].e_uid = + make_kuid(&init_user_ns, + je32_to_cpu(entry->e_id)); + break; + case ACL_GROUP: + value += sizeof(struct jffs2_acl_entry); + if (value > end) + goto fail; + acl->a_entries[i].e_gid = + make_kgid(&init_user_ns, + je32_to_cpu(entry->e_id)); + break; + + default: + goto fail; + } + } + if (value != end) + goto fail; + return acl; + fail: + posix_acl_release(acl); + return ERR_PTR(-EINVAL); +} + +static void *jffs2_acl_to_medium(const struct posix_acl *acl, size_t *size) +{ + struct jffs2_acl_header *header; + struct jffs2_acl_entry *entry; + void *e; + size_t i; + + *size = jffs2_acl_size(acl->a_count); + header = kmalloc_flex(*header, a_entries, acl->a_count); + if (!header) + return ERR_PTR(-ENOMEM); + header->a_version = cpu_to_je32(JFFS2_ACL_VERSION); + e = header + 1; + for (i=0; i < acl->a_count; i++) { + const struct posix_acl_entry *acl_e = &acl->a_entries[i]; + entry = e; + entry->e_tag = cpu_to_je16(acl_e->e_tag); + entry->e_perm = cpu_to_je16(acl_e->e_perm); + switch(acl_e->e_tag) { + case ACL_USER: + entry->e_id = cpu_to_je32( + from_kuid(&init_user_ns, acl_e->e_uid)); + e += sizeof(struct jffs2_acl_entry); + break; + case ACL_GROUP: + entry->e_id = cpu_to_je32( + from_kgid(&init_user_ns, acl_e->e_gid)); + e += sizeof(struct jffs2_acl_entry); + break; + + case ACL_USER_OBJ: + case ACL_GROUP_OBJ: + case ACL_MASK: + case ACL_OTHER: + e += sizeof(struct jffs2_acl_entry_short); + break; + + default: + goto fail; + } + } + return header; + fail: + kfree(header); + return ERR_PTR(-EINVAL); +} + +struct posix_acl *jffs2_get_acl(struct inode *inode, int type, bool rcu) +{ + struct posix_acl *acl; + char *value = NULL; + int rc, xprefix; + + if (rcu) + return ERR_PTR(-ECHILD); + + switch (type) { + case ACL_TYPE_ACCESS: + xprefix = JFFS2_XPREFIX_ACL_ACCESS; + break; + case ACL_TYPE_DEFAULT: + xprefix = JFFS2_XPREFIX_ACL_DEFAULT; + break; + default: + BUG(); + } + rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0); + if (rc > 0) { + value = kmalloc(rc, GFP_KERNEL); + if (!value) + return ERR_PTR(-ENOMEM); + rc = do_jffs2_getxattr(inode, xprefix, "", value, rc); + } + if (rc > 0) { + acl = jffs2_acl_from_medium(value, rc); + } else if (rc == -ENODATA || rc == -ENOSYS) { + acl = NULL; + } else { + acl = ERR_PTR(rc); + } + kfree(value); + return acl; +} + +static int __jffs2_set_acl(struct inode *inode, int xprefix, struct posix_acl *acl) +{ + char *value = NULL; + size_t size = 0; + int rc; + + if (acl) { + value = jffs2_acl_to_medium(acl, &size); + if (IS_ERR(value)) + return PTR_ERR(value); + } + rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0); + if (!value && rc == -ENODATA) + rc = 0; + kfree(value); + + return rc; +} + +int jffs2_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, + struct posix_acl *acl, int type) +{ + int rc, xprefix; + struct inode *inode = d_inode(dentry); + + switch (type) { + case ACL_TYPE_ACCESS: + xprefix = JFFS2_XPREFIX_ACL_ACCESS; + if (acl) { + umode_t mode; + + rc = posix_acl_update_mode(&nop_mnt_idmap, inode, &mode, + &acl); + if (rc) + return rc; + if (inode->i_mode != mode) { + struct iattr attr; + + attr.ia_valid = ATTR_MODE | ATTR_CTIME; + attr.ia_mode = mode; + attr.ia_ctime = current_time(inode); + rc = jffs2_do_setattr(inode, &attr); + if (rc < 0) + return rc; + } + } + break; + case ACL_TYPE_DEFAULT: + xprefix = JFFS2_XPREFIX_ACL_DEFAULT; + if (!S_ISDIR(inode->i_mode)) + return acl ? -EACCES : 0; + break; + default: + return -EINVAL; + } + rc = __jffs2_set_acl(inode, xprefix, acl); + if (!rc) + set_cached_acl(inode, type, acl); + return rc; +} + +int jffs2_init_acl_pre(struct inode *dir_i, struct inode *inode, umode_t *i_mode) +{ + struct posix_acl *default_acl, *acl; + int rc; + + cache_no_acl(inode); + + rc = posix_acl_create(dir_i, i_mode, &default_acl, &acl); + if (rc) + return rc; + + if (default_acl) { + set_cached_acl(inode, ACL_TYPE_DEFAULT, default_acl); + posix_acl_release(default_acl); + } + if (acl) { + set_cached_acl(inode, ACL_TYPE_ACCESS, acl); + posix_acl_release(acl); + } + return 0; +} + +int jffs2_init_acl_post(struct inode *inode) +{ + int rc; + + if (inode->i_default_acl) { + rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_DEFAULT, inode->i_default_acl); + if (rc) + return rc; + } + + if (inode->i_acl) { + rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_ACCESS, inode->i_acl); + if (rc) + return rc; + } + + return 0; +} -- cgit v1.3.1