diff options
| -rw-r--r-- | arch/arm64/include/asm/efi.h | 4 | ||||
| -rw-r--r-- | arch/arm64/kernel/Makefile | 3 | ||||
| -rw-r--r-- | arch/arm64/kernel/efi-rt-wrapper.S | 41 | ||||
| -rw-r--r-- | arch/arm64/kernel/efi.c | 6 |
4 files changed, 52 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h index 8389050328bb..192d791f1103 100644 --- a/arch/arm64/include/asm/efi.h +++ b/arch/arm64/include/asm/efi.h @@ -31,7 +31,7 @@ int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md); ({ \ efi_##f##_t *__f; \ __f = p->f; \ - __f(args); \ + __efi_rt_asm_wrapper(__f, #f, args); \ }) #define arch_efi_call_virt_teardown() \ @@ -40,6 +40,8 @@ int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md); efi_virtmap_unload(); \ }) +efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...); + #define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT) /* arch specific definitions used by the stub code */ diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index b87541360f43..6a4bd80c75bd 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -38,7 +38,8 @@ arm64-obj-$(CONFIG_CPU_PM) += sleep.o suspend.o arm64-obj-$(CONFIG_CPU_IDLE) += cpuidle.o arm64-obj-$(CONFIG_JUMP_LABEL) += jump_label.o arm64-obj-$(CONFIG_KGDB) += kgdb.o -arm64-obj-$(CONFIG_EFI) += efi.o efi-entry.stub.o +arm64-obj-$(CONFIG_EFI) += efi.o efi-entry.stub.o \ + efi-rt-wrapper.o arm64-obj-$(CONFIG_PCI) += pci.o arm64-obj-$(CONFIG_ARMV8_DEPRECATED) += armv8_deprecated.o arm64-obj-$(CONFIG_ACPI) += acpi.o diff --git a/arch/arm64/kernel/efi-rt-wrapper.S b/arch/arm64/kernel/efi-rt-wrapper.S new file mode 100644 index 000000000000..05235ebb336d --- /dev/null +++ b/arch/arm64/kernel/efi-rt-wrapper.S @@ -0,0 +1,41 @@ +/* + * Copyright (C) 2018 Linaro Ltd <ard.biesheuvel@linaro.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/linkage.h> + +ENTRY(__efi_rt_asm_wrapper) + stp x29, x30, [sp, #-32]! + mov x29, sp + + /* + * Register x18 is designated as the 'platform' register by the AAPCS, + * which means firmware running at the same exception level as the OS + * (such as UEFI) should never touch it. + */ + stp x1, x18, [sp, #16] + + /* + * We are lucky enough that no EFI runtime services take more than + * 5 arguments, so all are passed in registers rather than via the + * stack. + */ + mov x8, x0 + mov x0, x2 + mov x1, x3 + mov x2, x4 + mov x3, x5 + mov x4, x6 + blr x8 + + ldp x1, x2, [sp, #16] + cmp x2, x18 + ldp x29, x30, [sp], #32 + b.ne 0f + ret +0: b efi_handle_corrupted_x18 // tail call +ENDPROC(__efi_rt_asm_wrapper) diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c index a8bf1c892b90..4f9acb5fbe97 100644 --- a/arch/arm64/kernel/efi.c +++ b/arch/arm64/kernel/efi.c @@ -126,3 +126,9 @@ bool efi_poweroff_required(void) { return efi_enabled(EFI_RUNTIME_SERVICES); } + +asmlinkage efi_status_t efi_handle_corrupted_x18(efi_status_t s, const char *f) +{ + pr_err_ratelimited(FW_BUG "register x18 corrupted by EFI %s\n", f); + return s; +} |