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-rw-r--r--arch/arm64/kernel/Makefile3
-rw-r--r--arch/arm64/kernel/efi-rt-wrapper.S41
-rw-r--r--arch/arm64/kernel/efi.c6
-rw-r--r--arch/arm64/kernel/sys.c2
4 files changed, 50 insertions, 2 deletions
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;
+}
diff --git a/arch/arm64/kernel/sys.c b/arch/arm64/kernel/sys.c
index 26fe8ea93ea2..72981bae10eb 100644
--- a/arch/arm64/kernel/sys.c
+++ b/arch/arm64/kernel/sys.c
@@ -34,7 +34,7 @@ asmlinkage long sys_mmap(unsigned long addr, unsigned long len,
if (offset_in_page(off) != 0)
return -EINVAL;
- return sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
+ return ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
}
SYSCALL_DEFINE1(arm64_personality, unsigned int, personality)
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