From: Joerg Roedel
Add code needed to setup an IDT in the early pre-decompression
boot-code. The IDT is loaded first in startup_64, which is after
EfiExitBootServices() has been called, and later reloaded when the
kernel image has been relocated to the end of the decompression area.
This allows to setup different IDT handlers before and after the
relocation.
Signed-off-by: Joerg Roedel
Link: https://lore.kernel.org/r/20200724160336.5435-13-j...@8bytes.org
---
arch/x86/boot/compressed/Makefile | 1 +
arch/x86/boot/compressed/head_64.S | 25 +++-
arch/x86/boot/compressed/idt_64.c | 44 ++
arch/x86/boot/compressed/idt_handlers_64.S | 70 ++
arch/x86/boot/compressed/misc.h| 5 ++
arch/x86/include/asm/desc_defs.h | 3 +
6 files changed, 147 insertions(+), 1 deletion(-)
create mode 100644 arch/x86/boot/compressed/idt_64.c
create mode 100644 arch/x86/boot/compressed/idt_handlers_64.S
diff --git a/arch/x86/boot/compressed/Makefile
b/arch/x86/boot/compressed/Makefile
index 0acdaa8a7dab..ce85b24898b8 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -78,6 +78,7 @@ vmlinux-objs-$(CONFIG_EARLY_PRINTK) +=
$(obj)/early_serial_console.o
vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o
ifdef CONFIG_X86_64
vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr_64.o
+ vmlinux-objs-y += $(obj)/idt_64.o $(obj)/idt_handlers_64.o
vmlinux-objs-y += $(obj)/mem_encrypt.o
vmlinux-objs-y += $(obj)/pgtable_64.o
endif
diff --git a/arch/x86/boot/compressed/head_64.S
b/arch/x86/boot/compressed/head_64.S
index 9e46729cf162..260c7940f960 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -33,6 +33,7 @@
#include
#include
#include
+#include
#include "pgtable.h"
/*
@@ -415,6 +416,10 @@ SYM_CODE_START(startup_64)
.Lon_kernel_cs:
+ pushq %rsi
+ callload_stage1_idt
+ popq%rsi
+
/*
* paging_prepare() sets up the trampoline and checks if we need to
* enable 5-level paging.
@@ -527,6 +532,13 @@ SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated)
shrq$3, %rcx
rep stosq
+/*
+ * Load stage2 IDT
+ */
+ pushq %rsi
+ callload_stage2_idt
+ popq%rsi
+
/*
* Do the extraction, and jump to the new kernel..
*/
@@ -659,10 +671,21 @@ SYM_DATA_START_LOCAL(gdt)
.quad 0x /* TS continued */
SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end)
+SYM_DATA_START(boot_idt_desc)
+ .word boot_idt_end - boot_idt
+ .quad 0
+SYM_DATA_END(boot_idt_desc)
+ .balign 8
+SYM_DATA_START(boot_idt)
+ .rept BOOT_IDT_ENTRIES
+ .quad 0
+ .quad 0
+ .endr
+SYM_DATA_END_LABEL(boot_idt, SYM_L_GLOBAL, boot_idt_end)
+
#ifdef CONFIG_EFI_STUB
SYM_DATA(image_offset, .long 0)
#endif
-
#ifdef CONFIG_EFI_MIXED
SYM_DATA_LOCAL(efi32_boot_args, .long 0, 0, 0)
SYM_DATA(efi_is64, .byte 1)
diff --git a/arch/x86/boot/compressed/idt_64.c
b/arch/x86/boot/compressed/idt_64.c
new file mode 100644
index ..082cd6bca033
--- /dev/null
+++ b/arch/x86/boot/compressed/idt_64.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include
+#include
+#include
+#include "misc.h"
+
+static void set_idt_entry(int vector, void (*handler)(void))
+{
+ unsigned long address = (unsigned long)handler;
+ gate_desc entry;
+
+ memset(, 0, sizeof(entry));
+
+ entry.offset_low= (u16)(address & 0x);
+ entry.segment = __KERNEL_CS;
+ entry.bits.type = GATE_TRAP;
+ entry.bits.p= 1;
+ entry.offset_middle = (u16)((address >> 16) & 0x);
+ entry.offset_high = (u32)(address >> 32);
+
+ memcpy(_idt[vector], , sizeof(entry));
+}
+
+/* Have this here so we don't need to include */
+static void load_boot_idt(const struct desc_ptr *dtr)
+{
+ asm volatile("lidt %0"::"m" (*dtr));
+}
+
+/* Setup IDT before kernel jumping to .Lrelocated */
+void load_stage1_idt(void)
+{
+ boot_idt_desc.address = (unsigned long)boot_idt;
+
+ load_boot_idt(_idt_desc);
+}
+
+/* Setup IDT after kernel jumping to .Lrelocated */
+void load_stage2_idt(void)
+{
+ boot_idt_desc.address = (unsigned long)boot_idt;
+
+ load_boot_idt(_idt_desc);
+}
diff --git a/arch/x86/boot/compressed/idt_handlers_64.S
b/arch/x86/boot/compressed/idt_handlers_64.S
new file mode 100644
index ..36dee2f40a8b
--- /dev/null
+++ b/arch/x86/boot/compressed/idt_handlers_64.S
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Early IDT handler entry points
+ *
+ * Copyright (C) 2019 SUSE
+ *
+ * Author: Joerg Roedel
+ */
+
+#include
+
+/* For ORIG_RAX */
+#include "../../entry/calling.h"
+
+.macro EXCEPTION_HANDLER name function error_code=0
+SYM_FUNC_START(\name)
+
+ /* Build pt_regs */
+ .if
