From 99280413a5b785f22d91e8a8a66dc38f4a214495 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 4 Jun 2024 17:45:20 +0200 Subject: [PATCH] efi: Add missing __nocfi annotations to runtime wrappers The EFI runtime wrappers are a sandbox for calling into EFI runtime services, which are invoked using indirect calls. When running with kCFI enabled, the compiler will require the target of any indirect call to be type annotated. Given that the EFI runtime services prototypes and calling convention are governed by the EFI spec, not the Linux kernel, adding such type annotations for firmware routines is infeasible, and so the compiler must be informed that prototype validation should be omitted. Add the __nocfi annotation at the appropriate places in the EFI runtime wrapper code to achieve this. Note that this currently only affects 32-bit ARM, given that other architectures that support both kCFI and EFI use an asm wrapper to call EFI runtime services, and this hides the indirect call from the compiler. Fixes: 1a4fec49efe5 ("ARM: 9392/2: Support CLANG CFI") Reviewed-by: Linus Walleij Tested-by: Nathan Chancellor Signed-off-by: Ard Biesheuvel --- drivers/firmware/efi/runtime-wrappers.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c index 5d56bc40a79d..708b777857d3 100644 --- a/drivers/firmware/efi/runtime-wrappers.c +++ b/drivers/firmware/efi/runtime-wrappers.c @@ -213,7 +213,7 @@ extern struct semaphore __efi_uv_runtime_lock __alias(efi_runtime_lock); * Calls the appropriate efi_runtime_service() with the appropriate * arguments. */ -static void efi_call_rts(struct work_struct *work) +static void __nocfi efi_call_rts(struct work_struct *work) { const union efi_rts_args *args = efi_rts_work.args; efi_status_t status = EFI_NOT_FOUND; @@ -435,7 +435,7 @@ static efi_status_t virt_efi_set_variable(efi_char16_t *name, return status; } -static efi_status_t +static efi_status_t __nocfi virt_efi_set_variable_nb(efi_char16_t *name, efi_guid_t *vendor, u32 attr, unsigned long data_size, void *data) { @@ -469,7 +469,7 @@ static efi_status_t virt_efi_query_variable_info(u32 attr, return status; } -static efi_status_t +static efi_status_t __nocfi virt_efi_query_variable_info_nb(u32 attr, u64 *storage_space, u64 *remaining_space, u64 *max_variable_size) { @@ -499,10 +499,9 @@ static efi_status_t virt_efi_get_next_high_mono_count(u32 *count) return status; } -static void virt_efi_reset_system(int reset_type, - efi_status_t status, - unsigned long data_size, - efi_char16_t *data) +static void __nocfi +virt_efi_reset_system(int reset_type, efi_status_t status, + unsigned long data_size, efi_char16_t *data) { if (down_trylock(&efi_runtime_lock)) { pr_warn("failed to invoke the reset_system() runtime service:\n" -- 2.20.1