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/keys/Kconfig | 131 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 131 insertions(+) create mode 100644 security/keys/Kconfig (limited to 'security/keys/Kconfig') diff --git a/security/keys/Kconfig b/security/keys/Kconfig new file mode 100644 index 000000000..f4510d8cb --- /dev/null +++ b/security/keys/Kconfig @@ -0,0 +1,131 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Key management configuration +# + +menuconfig KEYS + bool "Enable access key retention support" + select ASSOCIATIVE_ARRAY + help + This option provides support for retaining authentication tokens and + access keys in the kernel. + + It also includes provision of methods by which such keys might be + associated with a process so that network filesystems, encryption + support and the like can find them. + + Furthermore, a special type of key is available that acts as keyring: + a searchable sequence of keys. Each process is equipped with access + to five standard keyrings: UID-specific, GID-specific, session, + process and thread. + + If you are unsure as to whether this is required, answer N. + +if KEYS + +config KEYS_REQUEST_CACHE + bool "Enable temporary caching of the last request_key() result" + help + This option causes the result of the last successful request_key() + call that didn't upcall to the kernel to be cached temporarily in the + task_struct. The cache is cleared by exit and just prior to the + resumption of userspace. + + This allows the key used for multiple step processes where each step + wants to request a key that is likely the same as the one requested + by the last step to save on the searching. + + An example of such a process is a pathwalk through a network + filesystem in which each method needs to request an authentication + key. Pathwalk will call multiple methods for each dentry traversed + (permission, d_revalidate, lookup, getxattr, getacl, ...). + +config PERSISTENT_KEYRINGS + bool "Enable register of persistent per-UID keyrings" + help + This option provides a register of persistent per-UID keyrings, + primarily aimed at Kerberos key storage. The keyrings are persistent + in the sense that they stay around after all processes of that UID + have exited, not that they survive the machine being rebooted. + + A particular keyring may be accessed by either the user whose keyring + it is or by a process with administrative privileges. The active + LSMs gets to rule on which admin-level processes get to access the + cache. + + Keyrings are created and added into the register upon demand and get + removed if they expire (a default timeout is set upon creation). + +config BIG_KEYS + bool "Large payload keys" + depends on TMPFS + select CRYPTO_LIB_CHACHA20POLY1305 + help + This option provides support for holding large keys within the kernel + (for example Kerberos ticket caches). The data may be stored out to + swapspace by tmpfs. + + If you are unsure as to whether this is required, answer N. + +config TRUSTED_KEYS + tristate "TRUSTED KEYS" + help + This option provides support for creating, sealing, and unsealing + keys in the kernel. Trusted keys are random number symmetric keys, + generated and sealed by a trust source selected at kernel boot-time. + Userspace will only ever see encrypted blobs. + + If you are unsure as to whether this is required, answer N. + +if TRUSTED_KEYS +source "security/keys/trusted-keys/Kconfig" +endif + +config ENCRYPTED_KEYS + tristate "ENCRYPTED KEYS" + select CRYPTO + select CRYPTO_AES + select CRYPTO_CBC + select CRYPTO_LIB_SHA256 + help + This option provides support for create/encrypting/decrypting keys + in the kernel. Encrypted keys are instantiated using kernel + generated random numbers or provided decrypted data, and are + encrypted/decrypted with a 'master' symmetric key. The 'master' + key can be either a trusted-key or user-key type. Only encrypted + blobs are ever output to Userspace. + + If you are unsure as to whether this is required, answer N. + +config USER_DECRYPTED_DATA + bool "Allow encrypted keys with user decrypted data" + depends on ENCRYPTED_KEYS + help + This option provides support for instantiating encrypted keys using + user-provided decrypted data. The decrypted data must be hex-ascii + encoded. + + If you are unsure as to whether this is required, answer N. + +config KEY_DH_OPERATIONS + bool "Diffie-Hellman operations on retained keys" + select CRYPTO + select CRYPTO_KDF800108_CTR + select CRYPTO_DH + help + This option provides support for calculating Diffie-Hellman + public keys and shared secrets using values stored as keys + in the kernel. + + If you are unsure as to whether this is required, answer N. + +config KEY_NOTIFICATIONS + bool "Provide key/keyring change notifications" + depends on WATCH_QUEUE + help + This option provides support for getting change notifications + on keys and keyrings on which the caller has View permission. + This makes use of pipes to handle the notification buffer and + provides KEYCTL_WATCH_KEY to enable/disable watches. + +endif # KEYS -- cgit v1.3.1