diff options
| -rw-r--r-- | arch/x86/Kbuild | 4 | ||||
| -rw-r--r-- | arch/x86/Makefile | 8 | ||||
| -rw-r--r-- | arch/x86/purgatory/Makefile | 30 | ||||
| -rw-r--r-- | arch/x86/purgatory/entry64.S | 101 | ||||
| -rw-r--r-- | arch/x86/purgatory/purgatory.c | 72 | ||||
| -rw-r--r-- | arch/x86/purgatory/setup-x86_64.S | 58 | ||||
| -rw-r--r-- | arch/x86/purgatory/stack.S | 19 | ||||
| -rw-r--r-- | arch/x86/purgatory/string.c | 13 |
8 files changed, 305 insertions, 0 deletions
diff --git a/arch/x86/Kbuild b/arch/x86/Kbuild index e5287d8517aa..61b6d51866f8 100644 --- a/arch/x86/Kbuild +++ b/arch/x86/Kbuild @@ -16,3 +16,7 @@ obj-$(CONFIG_IA32_EMULATION) += ia32/ obj-y += platform/ obj-y += net/ + +ifeq ($(CONFIG_X86_64),y) +obj-$(CONFIG_KEXEC) += purgatory/ +endif diff --git a/arch/x86/Makefile b/arch/x86/Makefile index c65fd9650467..c1aa36887843 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -183,6 +183,14 @@ archscripts: scripts_basic archheaders: $(Q)$(MAKE) $(build)=arch/x86/syscalls all +archprepare: +ifeq ($(CONFIG_KEXEC),y) +# Build only for 64bit. No loaders for 32bit yet. + ifeq ($(CONFIG_X86_64),y) + $(Q)$(MAKE) $(build)=arch/x86/purgatory arch/x86/purgatory/kexec-purgatory.c + endif +endif + ### # Kernel objects diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile new file mode 100644 index 000000000000..7fde9ee438a4 --- /dev/null +++ b/arch/x86/purgatory/Makefile @@ -0,0 +1,30 @@ +purgatory-y := purgatory.o stack.o setup-x86_$(BITS).o sha256.o entry64.o string.o + +targets += $(purgatory-y) +PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y)) + +LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined -nostdlib -z nodefaultlib +targets += purgatory.ro + +# Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That +# in turn leaves some undefined symbols like __fentry__ in purgatory and not +# sure how to relocate those. Like kexec-tools, use custom flags. + +KBUILD_CFLAGS := -fno-strict-aliasing -Wall -Wstrict-prototypes -fno-zero-initialized-in-bss -fno-builtin -ffreestanding -c -MD -Os -mcmodel=large + +$(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE + $(call if_changed,ld) + +targets += kexec-purgatory.c + +quiet_cmd_bin2c = BIN2C $@ + cmd_bin2c = cat $(obj)/purgatory.ro | $(objtree)/scripts/basic/bin2c kexec_purgatory > $(obj)/kexec-purgatory.c + +$(obj)/kexec-purgatory.c: $(obj)/purgatory.ro FORCE + $(call if_changed,bin2c) + + +# No loaders for 32bits yet. +ifeq ($(CONFIG_X86_64),y) + obj-$(CONFIG_KEXEC) += kexec-purgatory.o +endif diff --git a/arch/x86/purgatory/entry64.S b/arch/x86/purgatory/entry64.S new file mode 100644 index 000000000000..be3249d7ed2d --- /dev/null +++ b/arch/x86/purgatory/entry64.S @@ -0,0 +1,101 @@ +/* + * Copyright (C) 2003,2004 Eric Biederman (ebiederm@xmission.com) + * Copyright (C) 2014 Red Hat Inc. + + * Author(s): Vivek Goyal <vgoyal@redhat.com> + * + * This code has been taken from kexec-tools. + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. + */ + + .text + .balign 16 + .code64 + .globl entry64, entry64_regs + + +entry64: + /* Setup a gdt that should be preserved */ + lgdt gdt(%rip) + + /* load the data segments */ + movl $0x18, %eax /* data segment */ + movl %eax, %ds + movl %eax, %es + movl %eax, %ss + movl %eax, %fs + movl %eax, %gs + + /* Setup new stack */ + leaq stack_init(%rip), %rsp + pushq $0x10 /* CS */ + leaq new_cs_exit(%rip), %rax + pushq %rax + lretq +new_cs_exit: + + /* Load the registers */ + movq rax(%rip), %rax + movq rbx(%rip), %rbx + movq rcx(%rip), %rcx + movq rdx(%rip), %rdx + movq rsi(%rip), %rsi + movq rdi(%rip), %rdi + movq rsp(%rip), %rsp + movq rbp(%rip), %rbp + movq r8(%rip), %r8 + movq r9(%rip), %r9 + movq r10(%rip), %r10 + movq r11(%rip), %r11 + movq r12(%rip), %r12 + movq r13(%rip), %r13 + movq r14(%rip), %r14 + movq r15(%rip), %r15 + + /* Jump to the new code... */ + jmpq *rip(%rip) + + .section ".rodata" + .balign 4 +entry64_regs: +rax: .quad 0x0 +rbx: .quad 0x0 +rcx: .quad 0x0 +rdx: .quad 0x0 +rsi: .quad 0x0 +rdi: .quad 0x0 +rsp: .quad 0x0 +rbp: .quad 0x0 +r8: .quad 0x0 +r9: .quad 0x0 +r10: .quad 0x0 +r11: .quad 0x0 +r12: .quad 0x0 +r13: .quad 0x0 +r14: .quad 0x0 +r15: .quad 0x0 +rip: .quad 0x0 + .size entry64_regs, . - entry64_regs + + /* GDT */ + .section ".rodata" + .balign 16 +gdt: + /* 0x00 unusable segment + * 0x08 unused + * so use them as gdt ptr + */ + .word gdt_end - gdt - 1 + .quad gdt + .word 0, 0, 0 + + /* 0x10 4GB flat code segment */ + .word 0xFFFF, 0x0000, 0x9A00, 0x00AF + + /* 0x18 4GB flat data segment */ + .word 0xFFFF, 0x0000, 0x9200, 0x00CF +gdt_end: +stack: .quad 0, 0 +stack_init: diff --git a/arch/x86/purgatory/purgatory.c b/arch/x86/purgatory/purgatory.c new file mode 100644 index 000000000000..25e068ba3382 --- /dev/null +++ b/arch/x86/purgatory/purgatory.c @@ -0,0 +1,72 @@ +/* + * purgatory: Runs between two kernels + * + * Copyright (C) 2014 Red Hat Inc. + * + * Author: + * Vivek Goyal <vgoyal@redhat.com> + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. + */ + +#include "sha256.h" +#include "../boot/string.h" + +struct sha_region { + unsigned long start; + unsigned long len; +}; + +unsigned long backup_dest = 0; +unsigned long backup_src = 0; +unsigned long backup_sz = 0; + +u8 sha256_digest[SHA256_DIGEST_SIZE] = { 0 }; + +struct sha_region sha_regions[16] = {}; + +/* + * On x86, second kernel requries first 640K of memory to boot. Copy + * first 640K to a backup region in reserved memory range so that second + * kernel can use first 640K. + */ +static int copy_backup_region(void) +{ + if (backup_dest) + memcpy((void *)backup_dest, (void *)backup_src, backup_sz); + + return 0; +} + +int verify_sha256_digest(void) +{ + struct sha_region *ptr, *end; + u8 digest[SHA256_DIGEST_SIZE]; + struct sha256_state sctx; + + sha256_init(&sctx); + end = &sha_regions[sizeof(sha_regions)/sizeof(sha_regions[0])]; + for (ptr = sha_regions; ptr < end; ptr++) + sha256_update(&sctx, (uint8_t *)(ptr->start), ptr->len); + + sha256_final(&sctx, digest); + + if (memcmp(digest, sha256_digest, sizeof(digest))) + return 1; + + return 0; +} + +void purgatory(void) +{ + int ret; + + ret = verify_sha256_digest(); + if (ret) { + /* loop forever */ + for (;;) + ; + } + copy_backup_region(); +} diff --git a/arch/x86/purgatory/setup-x86_64.S b/arch/x86/purgatory/setup-x86_64.S new file mode 100644 index 000000000000..fe3c91ba1bd0 --- /dev/null +++ b/arch/x86/purgatory/setup-x86_64.S @@ -0,0 +1,58 @@ +/* + * purgatory: setup code + * + * Copyright (C) 2003,2004 Eric Biederman (ebiederm@xmission.com) + * Copyright (C) 2014 Red Hat Inc. + * + * This code has been taken from kexec-tools. + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. + */ + + .text + .globl purgatory_start + .balign 16 +purgatory_start: + .code64 + + /* Load a gdt so I know what the segment registers are */ + lgdt gdt(%rip) + + /* load the data segments */ + movl $0x18, %eax /* data segment */ + movl %eax, %ds + movl %eax, %es + movl %eax, %ss + movl %eax, %fs + movl %eax, %gs + + /* Setup a stack */ + leaq lstack_end(%rip), %rsp + + /* Call the C code */ + call purgatory + jmp entry64 + + .section ".rodata" + .balign 16 +gdt: /* 0x00 unusable segment + * 0x08 unused + * so use them as the gdt ptr + */ + .word gdt_end - gdt - 1 + .quad gdt + .word 0, 0, 0 + + /* 0x10 4GB flat code segment */ + .word 0xFFFF, 0x0000, 0x9A00, 0x00AF + + /* 0x18 4GB flat data segment */ + .word 0xFFFF, 0x0000, 0x9200, 0x00CF +gdt_end: + + .bss + .balign 4096 +lstack: + .skip 4096 +lstack_end: diff --git a/arch/x86/purgatory/stack.S b/arch/x86/purgatory/stack.S new file mode 100644 index 000000000000..3cefba1fefc8 --- /dev/null +++ b/arch/x86/purgatory/stack.S @@ -0,0 +1,19 @@ +/* + * purgatory: stack + * + * Copyright (C) 2014 Red Hat Inc. + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. + */ + + /* A stack for the loaded kernel. + * Seperate and in the data section so it can be prepopulated. + */ + .data + .balign 4096 + .globl stack, stack_end + +stack: + .skip 4096 +stack_end: diff --git a/arch/x86/purgatory/string.c b/arch/x86/purgatory/string.c new file mode 100644 index 000000000000..d886b1fa36f0 --- /dev/null +++ b/arch/x86/purgatory/string.c @@ -0,0 +1,13 @@ +/* + * Simple string functions. + * + * Copyright (C) 2014 Red Hat Inc. + * + * Author: + * Vivek Goyal <vgoyal@redhat.com> + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. + */ + +#include "../boot/string.c" |