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 --- security/tomoyo/memory.c | 207 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 207 insertions(+) create mode 100644 security/tomoyo/memory.c (limited to 'security/tomoyo/memory.c') diff --git a/security/tomoyo/memory.c b/security/tomoyo/memory.c new file mode 100644 index 000000000..1b570bde7 --- /dev/null +++ b/security/tomoyo/memory.c @@ -0,0 +1,207 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * security/tomoyo/memory.c + * + * Copyright (C) 2005-2011 NTT DATA CORPORATION + */ + +#include +#include +#include "common.h" + +/** + * tomoyo_warn_oom - Print out of memory warning message. + * + * @function: Function's name. + */ +void tomoyo_warn_oom(const char *function) +{ + /* Reduce error messages. */ + static pid_t tomoyo_last_pid; + const pid_t pid = current->pid; + + if (tomoyo_last_pid != pid) { + pr_warn("ERROR: Out of memory at %s.\n", function); + tomoyo_last_pid = pid; + } + if (!tomoyo_policy_loaded) + panic("MAC Initialization failed.\n"); +} + +/* Memoy currently used by policy/audit log/query. */ +unsigned int tomoyo_memory_used[TOMOYO_MAX_MEMORY_STAT]; +/* Memory quota for "policy"/"audit log"/"query". */ +unsigned int tomoyo_memory_quota[TOMOYO_MAX_MEMORY_STAT]; + +/** + * tomoyo_memory_ok - Check memory quota. + * + * @ptr: Pointer to allocated memory. + * + * Returns true on success, false otherwise. + * + * Returns true if @ptr is not NULL and quota not exceeded, false otherwise. + * + * Caller holds tomoyo_policy_lock mutex. + */ +bool tomoyo_memory_ok(void *ptr) +{ + if (ptr) { + const size_t s = ksize(ptr); + + tomoyo_memory_used[TOMOYO_MEMORY_POLICY] += s; + if (!tomoyo_memory_quota[TOMOYO_MEMORY_POLICY] || + tomoyo_memory_used[TOMOYO_MEMORY_POLICY] <= + tomoyo_memory_quota[TOMOYO_MEMORY_POLICY]) + return true; + tomoyo_memory_used[TOMOYO_MEMORY_POLICY] -= s; + } + tomoyo_warn_oom(__func__); + return false; +} + +/** + * tomoyo_commit_ok - Check memory quota. + * + * @data: Data to copy from. + * @size: Size in byte. + * + * Returns pointer to allocated memory on success, NULL otherwise. + * @data is zero-cleared on success. + * + * Caller holds tomoyo_policy_lock mutex. + */ +void *tomoyo_commit_ok(void *data, const unsigned int size) +{ + void *ptr = kzalloc(size, GFP_NOFS | __GFP_NOWARN); + + if (tomoyo_memory_ok(ptr)) { + memmove(ptr, data, size); + memset(data, 0, size); + return ptr; + } + kfree(ptr); + return NULL; +} + +/** + * tomoyo_get_group - Allocate memory for "struct tomoyo_path_group"/"struct tomoyo_number_group". + * + * @param: Pointer to "struct tomoyo_acl_param". + * @idx: Index number. + * + * Returns pointer to "struct tomoyo_group" on success, NULL otherwise. + */ +struct tomoyo_group *tomoyo_get_group(struct tomoyo_acl_param *param, + const u8 idx) +{ + struct tomoyo_group e = { }; + struct tomoyo_group *group = NULL; + struct list_head *list; + const char *group_name = tomoyo_read_token(param); + bool found = false; + + if (!tomoyo_correct_word(group_name) || idx >= TOMOYO_MAX_GROUP) + return NULL; + e.group_name = tomoyo_get_name(group_name); + if (!e.group_name) + return NULL; + if (mutex_lock_interruptible(&tomoyo_policy_lock)) + goto out; + list = ¶m->ns->group_list[idx]; + list_for_each_entry(group, list, head.list) { + if (e.group_name != group->group_name || + atomic_read(&group->head.users) == TOMOYO_GC_IN_PROGRESS) + continue; + atomic_inc(&group->head.users); + found = true; + break; + } + if (!found) { + struct tomoyo_group *entry = tomoyo_commit_ok(&e, sizeof(e)); + + if (entry) { + INIT_LIST_HEAD(&entry->member_list); + atomic_set(&entry->head.users, 1); + list_add_tail_rcu(&entry->head.list, list); + group = entry; + found = true; + } + } + mutex_unlock(&tomoyo_policy_lock); +out: + tomoyo_put_name(e.group_name); + return found ? group : NULL; +} + +/* + * tomoyo_name_list is used for holding string data used by TOMOYO. + * Since same string data is likely used for multiple times (e.g. + * "/lib/libc-2.5.so"), TOMOYO shares string data in the form of + * "const struct tomoyo_path_info *". + */ +struct list_head tomoyo_name_list[TOMOYO_MAX_HASH]; + +/** + * tomoyo_get_name - Allocate permanent memory for string data. + * + * @name: The string to store into the permernent memory. + * + * Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise. + */ +const struct tomoyo_path_info *tomoyo_get_name(const char *name) +{ + struct tomoyo_name *ptr; + unsigned int hash; + int len; + struct list_head *head; + + if (!name) + return NULL; + len = strlen(name) + 1; + hash = full_name_hash(NULL, (const unsigned char *) name, len - 1); + head = &tomoyo_name_list[hash_long(hash, TOMOYO_HASH_BITS)]; + if (mutex_lock_interruptible(&tomoyo_policy_lock)) + return NULL; + list_for_each_entry(ptr, head, head.list) { + if (hash != ptr->entry.hash || strcmp(name, ptr->entry.name) || + atomic_read(&ptr->head.users) == TOMOYO_GC_IN_PROGRESS) + continue; + atomic_inc(&ptr->head.users); + goto out; + } + ptr = kzalloc(sizeof(*ptr) + len, GFP_NOFS | __GFP_NOWARN); + if (tomoyo_memory_ok(ptr)) { + ptr->entry.name = ((char *) ptr) + sizeof(*ptr); + memmove((char *) ptr->entry.name, name, len); + atomic_set(&ptr->head.users, 1); + tomoyo_fill_path_info(&ptr->entry); + list_add_tail(&ptr->head.list, head); + } else { + kfree(ptr); + ptr = NULL; + } +out: + mutex_unlock(&tomoyo_policy_lock); + return ptr ? &ptr->entry : NULL; +} + +/* Initial namespace.*/ +struct tomoyo_policy_namespace tomoyo_kernel_namespace; + +/** + * tomoyo_mm_init - Initialize mm related code. + */ +void __init tomoyo_mm_init(void) +{ + int idx; + + for (idx = 0; idx < TOMOYO_MAX_HASH; idx++) + INIT_LIST_HEAD(&tomoyo_name_list[idx]); + tomoyo_kernel_namespace.name = ""; + tomoyo_init_policy_namespace(&tomoyo_kernel_namespace); + tomoyo_kernel_domain.ns = &tomoyo_kernel_namespace; + INIT_LIST_HEAD(&tomoyo_kernel_domain.acl_info_list); + tomoyo_kernel_domain.domainname = tomoyo_get_name(""); + list_add_tail_rcu(&tomoyo_kernel_domain.list, &tomoyo_domain_list); +} -- cgit v1.3.1