This is loader specific code which can load bzImage and set it up for
64bit entry. This does not take care of 32bit entry or real mode entry
yet.
Signed-off-by: Vivek Goyal <vgoyal at redhat.com>
---
arch/x86/include/asm/kexec-bzimage.h | 12 +
arch/x86/include/asm/kexec.h | 26 +++
arch/x86/kernel/Makefile | 2 +
arch/x86/kernel/kexec-bzimage.c | 375 ++++++++++++++++++++++++++++++++++
arch/x86/kernel/machine_kexec_64.c | 4 +-
arch/x86/kernel/purgatory_entry_64.S | 119 +++++++++++
6 files changed, 537 insertions(+), 1 deletions(-)
create mode 100644 arch/x86/include/asm/kexec-bzimage.h
create mode 100644 arch/x86/kernel/kexec-bzimage.c
create mode 100644 arch/x86/kernel/purgatory_entry_64.S
diff --git a/arch/x86/include/asm/kexec-bzimage.h b/arch/x86/include/asm/kexec-bzimage.h
new file mode 100644
index 0000000..d556727
--- /dev/null
+++ b/arch/x86/include/asm/kexec-bzimage.h
@@ -0,0 +1,12 @@
+#ifndef _ASM_BZIMAGE_H
+#define _ASM_BZIMAGE_H
+
+extern int bzImage64_probe(const char *buf, unsigned long len);
+extern void *bzImage64_load(struct kimage *image, char *kernel,
+ unsigned long kernel_len, char *initrd,
+ unsigned long initrd_len, char *cmdline,
+ unsigned long cmdline_len);
+extern int bzImage64_prep_entry(struct kimage *image);
+extern int bzImage64_cleanup(struct kimage *image);
+
+#endif /* _ASM_BZIMAGE_H */
diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
index 17483a4..94f1257 100644
--- a/arch/x86/include/asm/kexec.h
+++ b/arch/x86/include/asm/kexec.h
@@ -15,6 +15,9 @@
# define PAGES_NR 4
#endif
+#define KEXEC_PURGATORY_PAGE_SIZE 4096
+#define KEXEC_PURGATORY_CODE_MAX_SIZE 2048
+
# define KEXEC_CONTROL_CODE_MAX_SIZE 2048
#ifndef __ASSEMBLY__
@@ -141,6 +144,9 @@ relocate_kernel(unsigned long indirection_page,
unsigned long page_list,
unsigned long start_address,
unsigned int preserve_context);
+void purgatory_entry64(void);
+extern unsigned long purgatory_entry64_regs;
+extern struct desc_struct entry64_gdt;
#endif
#define ARCH_HAS_KIMAGE_ARCH
@@ -161,6 +167,26 @@ struct kimage_arch {
pmd_t *pmd;
pte_t *pte;
};
+
+struct kexec_entry64_regs {
+ uint64_t rax;
+ uint64_t rbx;
+ uint64_t rcx;
+ uint64_t rdx;
+ uint64_t rsi;
+ uint64_t rdi;
+ uint64_t rsp;
+ uint64_t rbp;
+ uint64_t r8;
+ uint64_t r9;
+ uint64_t r10;
+ uint64_t r11;
+ uint64_t r12;
+ uint64_t r13;
+ uint64_t r14;
+ uint64_t r15;
+ uint64_t rip;
+};
#endif
typedef void crash_vmclear_fn(void);
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 9b0a34e..5d074c2 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -68,6 +68,7 @@ obj-$(CONFIG_FTRACE_SYSCALLS) += ftrace.o
obj-$(CONFIG_X86_TSC) += trace_clock.o
obj-$(CONFIG_KEXEC) += machine_kexec_$(BITS).o
obj-$(CONFIG_KEXEC) += relocate_kernel_$(BITS).o crash.o
+obj-$(CONFIG_KEXEC) += kexec-bzimage.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump_$(BITS).o
obj-y += kprobes/
obj-$(CONFIG_MODULES) += module.o
@@ -122,4 +123,5 @@ ifeq ($(CONFIG_X86_64),y)
obj-$(CONFIG_PCI_MMCONFIG) += mmconf-fam10h_64.o
obj-y += vsmp_64.o
+ obj-$(CONFIG_KEXEC) += purgatory_entry_64.o
endif
diff --git a/arch/x86/kernel/kexec-bzimage.c b/arch/x86/kernel/kexec-bzimage.c
new file mode 100644
index 0000000..a1032d4
--- /dev/null
+++ b/arch/x86/kernel/kexec-bzimage.c
@@ -0,0 +1,375 @@
+#include <linux/string.h>
+#include <linux/printk.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/kexec.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+
+#include <asm/bootparam.h>
+#include <asm/setup.h>
+
+#ifdef CONFIG_X86_64
+
+struct bzimage64_data {
+ unsigned long kernel_load_addr;
+ unsigned long bootparams_load_addr;
+
+ /*
+ * Temporary buffer to hold bootparams buffer. This should be
+ * freed once the bootparam segment has been loaded.
+ */
+ void *bootparams_buf;
+ struct page *purgatory_page;
+};
+
+int bzImage64_probe(const char *buf, unsigned long len)
+{
+ int ret = -ENOEXEC;
+ struct setup_header *header;
+
+ if (len < 2 * 512) {
+ pr_debug("File is too short to be a bzImage\n");
+ return ret;
+ }
+
+ header = (struct setup_header *)(buf + 0x1F1);
+ if (memcmp((char *)&header->header, "HdrS", 4) != 0) {
+ pr_debug("Not a bzImage\n");
+ return ret;
+ }
+
+ if (header->boot_flag != 0xAA55) {
+ /* No x86 boot sector present */
+ pr_debug("No x86 boot sector present\n");
+ return ret;
+ }
+
+ if (header->version < 0x020C) {
+ /* Must be at least protocol version 2.12 */
+ pr_debug("Must be at least protocol version 2.12\n");
+ return ret;
+ }
+
+ if ((header->loadflags & 1) == 0) {
+ /* Not a bzImage */
+ pr_debug("zImage not a bzImage\n");
+ return ret;
+ }
+
+ if ((header->xloadflags & 3) != 3) {
+ /* XLF_KERNEL_64 and XLF_CAN_BE_LOADED_ABOVE_4G should be set */
+ pr_debug("Not a relocatable bzImage64\n");
+ return ret;
+ }
+
+ /* I've got a bzImage */
+ pr_debug("It's a relocatable bzImage64\n");
+ ret = 0;
+
+ return ret;
+}
+
+static int setup_memory_map_entries(struct boot_params *params)
+{
+ unsigned int nr_e820_entries;
+
+ /* TODO: What about EFI */
+ nr_e820_entries = e820_saved.nr_map;
+ if (nr_e820_entries > E820MAX)
+ nr_e820_entries = E820MAX;
+
+ params->e820_entries = nr_e820_entries;
+ memcpy(¶ms->e820_map, &e820_saved.map,
+ nr_e820_entries * sizeof(struct e820entry));
+
+ return 0;
+}
+
+static void setup_linux_system_parameters(struct boot_params *params)
+{
+ unsigned int nr_e820_entries;
+ unsigned long long mem_k, start, end;
+ int i;
+
+ /* Get subarch from existing bootparams */
+ params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch;
+
+ /* Copying screen_info will do? */
+ memcpy(¶ms->screen_info, &boot_params.screen_info,
+ sizeof(struct screen_info));
+
+ /* Fill in memsize later */
+ params->screen_info.ext_mem_k = 0;
+ params->alt_mem_k = 0;
+
+ /* Default APM info */
+ memset(¶ms->apm_bios_info, 0, sizeof(params->apm_bios_info));
+
+ /* Default drive info */
+ memset(¶ms->hd0_info, 0, sizeof(params->hd0_info));
+ memset(¶ms->hd1_info, 0, sizeof(params->hd1_info));
+
+ /* Default sysdesc table */
+ params->sys_desc_table.length = 0;
+
+ setup_memory_map_entries(params);
+ nr_e820_entries = params->e820_entries;
+
+ for(i = 0; i < nr_e820_entries; i++) {
+ if (params->e820_map[i].type != E820_RAM)
+ continue;
+ start = params->e820_map[i].addr;
+ end = params->e820_map[i].addr + params->e820_map[i].size - 1;
+
+ if ((start <= 0x100000) && end > 0x100000) {
+ mem_k = (end >> 10) - (0x100000 >> 10);
+ params->screen_info.ext_mem_k = mem_k;
+ params->alt_mem_k = mem_k;
+ if (mem_k > 0xfc00)
+ params->screen_info.ext_mem_k = 0xfc00; /* 64M*/
+ if (mem_k > 0xffffffff)
+ params->alt_mem_k = 0xffffffff;
+ }
+ }
+
+ /* Setup EDD info */
+ memcpy(params->eddbuf, boot_params.eddbuf,
+ EDDMAXNR * sizeof(struct edd_info));
+ params->eddbuf_entries = boot_params.eddbuf_entries;
+
+ memcpy(params->edd_mbr_sig_buffer, boot_params.edd_mbr_sig_buffer,
+ EDD_MBR_SIG_MAX * sizeof(unsigned int));
+}
+
+static void setup_initrd(struct boot_params *boot_params, unsigned long initrd_load_addr, unsigned long initrd_len)
+{
+ boot_params->hdr.ramdisk_image = initrd_load_addr & 0xffffffffUL;
+ boot_params->hdr.ramdisk_size = initrd_len & 0xffffffffUL;
+
+ boot_params->ext_ramdisk_image = initrd_load_addr >> 32;
+ boot_params->ext_ramdisk_size = initrd_len >> 32;
+}
+
+static void setup_cmdline(struct boot_params *boot_params,
+ unsigned long bootparams_load_addr,
+ unsigned long cmdline_offset, char *cmdline,
+ unsigned long cmdline_len)
+{
+ char *cmdline_ptr = ((char *)boot_params) + cmdline_offset;
+ unsigned long cmdline_ptr_phys;
+ uint32_t cmdline_low_32, cmdline_ext_32;
+
+ memcpy(cmdline_ptr, cmdline, cmdline_len);
+ cmdline_ptr[cmdline_len - 1] = '\0';
+
+ cmdline_ptr_phys = bootparams_load_addr + cmdline_offset;
+ cmdline_low_32 = cmdline_ptr_phys & 0xffffffffUL;
+ cmdline_ext_32 = cmdline_ptr_phys >> 32;
+
+ boot_params->hdr.cmd_line_ptr = cmdline_low_32;
+ if (cmdline_ext_32)
+ boot_params->ext_cmd_line_ptr = cmdline_ext_32;
+}
+
+void *bzImage64_load(struct kimage *image, char *kernel,
+ unsigned long kernel_len,
+ char *initrd, unsigned long initrd_len,
+ char *cmdline, unsigned long cmdline_len)
+{
+
+ struct setup_header *header;
+ int setup_sects, kern16_size_needed, kern16_size, ret = 0;
+ unsigned long setup_size, setup_header_size;
+ struct boot_params *params;
+ unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr;
+ unsigned long kernel_bufsz, kernel_memsz, kernel_align;
+ char *kernel_buf;
+ struct bzimage64_data *ldata;
+
+ header = (struct setup_header *)(kernel + 0x1F1);
+ setup_sects = header->setup_sects;
+ if (setup_sects == 0)
+ setup_sects = 4;
+
+ kern16_size = (setup_sects + 1) * 512;
+ if (kernel_len < kern16_size) {
+ pr_debug("bzImage truncated\n");
+ return ERR_PTR(-ENOEXEC);
+ }
+
+ if (cmdline_len > header->cmdline_size) {
+ pr_debug("Kernel command line too long\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ /* Allocate loader specific data */
+ ldata = kzalloc(sizeof(struct bzimage64_data), GFP_KERNEL);
+ if (!ldata)
+ return ERR_PTR(-ENOMEM);
+
+ /* Argument/parameter segment */
+ kern16_size_needed = kern16_size;
+ if (kern16_size_needed < 4096)
+ kern16_size_needed = 4096;
+
+ setup_size = kern16_size_needed + cmdline_len;
+ params = kzalloc(setup_size, GFP_KERNEL);
+ if (!params) {
+ ret = -ENOMEM;
+ goto out_free_loader_data;
+ }
+
+ /* Copy setup header onto bootparams. */
+ setup_header_size = 0x0202 + kernel[0x0201] - 0x1F1;
+
+ /* Is there a limit on setup header size? */
+ memcpy(¶ms->hdr, (kernel + 0x1F1), setup_header_size);
+ ret = kexec_add_buffer(image, (char *)params, setup_size,
+ setup_size, 16, 0x3000, -1, 1, &bootparam_load_addr);
+ if (ret)
+ goto out_free_params;
+ pr_debug("Loaded boot_param and command line at 0x%lx\n",
+ bootparam_load_addr);
+
+ /* Load kernel */
+ kernel_buf = kernel + kern16_size;
+ kernel_bufsz = kernel_len - kern16_size;
+ kernel_memsz = ALIGN(header->init_size, 4096);
+ kernel_align = header->kernel_alignment;
+
+ ret = kexec_add_buffer(image, kernel_buf,
+ kernel_bufsz, kernel_memsz, kernel_align, 0x100000,
+ -1, 1, &kernel_load_addr);
+ if (ret)
+ goto out_free_params;
+
+ pr_debug("Loaded 64bit kernel at 0x%lx sz = 0x%lx\n", kernel_load_addr,
+ kernel_memsz);
+
+ /* Load initrd high */
+ if (initrd) {
+ ret = kexec_add_buffer(image, initrd, initrd_len, initrd_len,
+ 4096, 0x10000000, ULONG_MAX, 1, &initrd_load_addr);
+ if (ret)
+ goto out_free_params;
+
+ pr_debug("Loaded initrd at 0x%lx sz = 0x%lx\n",
+ initrd_load_addr, initrd_len);
+ setup_initrd(params, initrd_load_addr, initrd_len);
+ }
+
+ setup_cmdline(params, bootparam_load_addr, kern16_size_needed,
+ cmdline, cmdline_len);
+
+ /* bootloader info. Do we need a separate ID for kexec kernel loader? */
+ params->hdr.type_of_loader = 0x0D << 4;
+ params->hdr.loadflags = 0;
+
+ setup_linux_system_parameters(params);
+
+ /*
+ * Allocate a purgatory page. For 64bit entry point, purgatory
+ * code can be anywhere.
+ *
+ * Control page allocation logic goes through segment list to
+ * make sure allocated page is not destination page. So allocate
+ * control page after all required segment have been prepared.
+ */
+ ldata->purgatory_page = kimage_alloc_control_pages(image,
+ get_order(KEXEC_PURGATORY_PAGE_SIZE));
+
+ if (!ldata->purgatory_page) {
+ printk(KERN_ERR "Could not allocate purgatory page\n");
+ ret = -ENOMEM;
+ goto out_free_params;
+ }
+
+ /*
+ * Store pointer to params so that it could be freed after loading
+ * params segment has been loaded and contents have been copied
+ * somewhere else.
+ */
+ ldata->bootparams_buf = params;
+ ldata->kernel_load_addr = kernel_load_addr;
+ ldata->bootparams_load_addr = bootparam_load_addr;
+ return ldata;
+
+out_free_params:
+ kfree(params);
+out_free_loader_data:
+ kfree(ldata);
+ return ERR_PTR(ret);
+}
+
+int bzImage64_prep_entry(struct kimage *image)
+{
+ struct bzimage64_data *ldata;
+ char *purgatory_page;
+ unsigned long regs_offset, gdt_offset, purgatory_page_phys;
+ struct kexec_entry64_regs *regs;
+ char *gdt_ptr;
+ unsigned long long *gdt_addr;
+
+ if (!image->file_mode)
+ return 0;
+
+ ldata = image->image_loader_data;
+ if (!ldata)
+ return -EINVAL;
+
+ /* Copy purgatory code to its control page */
+ purgatory_page = page_address(ldata->purgatory_page);
+
+ /* Physical address of purgatory page */
+ purgatory_page_phys = PFN_PHYS(page_to_pfn(ldata->purgatory_page));
+
+ memcpy(purgatory_page, purgatory_entry64,
+ KEXEC_PURGATORY_CODE_MAX_SIZE);
+
+ /* Set registers appropriately */
+ regs_offset = (unsigned long)&purgatory_entry64_regs -
+ (unsigned long)purgatory_entry64;
+ regs = (struct kexec_entry64_regs *) (purgatory_page + regs_offset);
+
+ regs->rbx = 0; /* Bootstrap Processor */
+ regs->rsi = ldata->bootparams_load_addr;
+ regs->rip = ldata->kernel_load_addr + 0x200;
+
+ /* Fix up gdt */
+ gdt_offset = (unsigned long)&entry64_gdt -
+ (unsigned long)purgatory_entry64;
+
+ gdt_ptr = purgatory_page + gdt_offset;
+
+ /* Skip a word which contains size of gdt table */
+ gdt_addr = (unsigned long long *)(gdt_ptr + 2);
+
+ *gdt_addr = (unsigned long long)gdt_ptr;
+
+ /*
+ * Update the relocated address of gdt. By the time we load gdt
+ * in purgatory, we are running using identity mapped tables.
+ * Load identity mapped address here.
+ */
+ *gdt_addr = (unsigned long long)(purgatory_page_phys + gdt_offset);
+
+ /*
+ * Jump to purgatory after control page. By the time we jump to
+ * purgatory, we are using itentifiy mapped page tables
+ */
+ kimage_set_start_addr(image, purgatory_page_phys);
+ return 0;
+}
+
+/* This cleanup function is called after various segments have been loaded */
+int bzImage64_cleanup(struct kimage *image)
+{
+ struct bzimage64_data *ldata = image->image_loader_data;
+
+ kfree(ldata->bootparams_buf);
+ ldata->bootparams_buf = NULL;
+ return 0;
+}
+
+#endif /* CONFIG_X86_64 */
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index fb41b73..a66ce1d 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -21,10 +21,12 @@
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
#include <asm/debugreg.h>
+#include <asm/kexec-bzimage.h>
/* arch dependent functionality related to kexec file based syscall */
static struct kexec_file_type kexec_file_type[]={
- {"", NULL, NULL, NULL, NULL},
+ {"bzImage64", bzImage64_probe, bzImage64_load, bzImage64_prep_entry,
+ bzImage64_cleanup},
};
static int nr_file_types = sizeof(kexec_file_type)/sizeof(kexec_file_type[0]);
diff --git a/arch/x86/kernel/purgatory_entry_64.S b/arch/x86/kernel/purgatory_entry_64.S
new file mode 100644
index 0000000..12a235f
--- /dev/null
+++ b/arch/x86/kernel/purgatory_entry_64.S
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2013 Red Hat Inc.
+ *
+ * Author(s): Vivek Goyal <vgoyal at redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+/*
+ * One page for purgatory. Code occupies first KEXEC_PURGATORY_CODE_MAX_SIZE
+ * bytes. Rest is for data/stack etc.
+ */
+#include <asm/page.h>
+
+ .text
+ .align PAGE_SIZE
+ .code64
+ .globl purgatory_entry64, purgatory_entry64_regs, entry64_gdt
+
+
+purgatory_entry64:
+ /* Setup a gdt that should be preserved */
+ lgdt entry64_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 except rsp. rsp is already loaded with stack
+ * at the end of this page
+ */
+ 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 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)
+
+ .balign 16
+purgatory_entry64_regs:
+rax: .quad 0x00000000
+rbx: .quad 0x00000000
+rcx: .quad 0x00000000
+rdx: .quad 0x00000000
+rsi: .quad 0x00000000
+rdi: .quad 0x00000000
+rsp: .quad 0x00000000
+rbp: .quad 0x00000000
+r8: .quad 0x00000000
+r9: .quad 0x00000000
+r10: .quad 0x00000000
+r11: .quad 0x00000000
+r12: .quad 0x00000000
+r13: .quad 0x00000000
+r14: .quad 0x00000000
+r15: .quad 0x00000000
+rip: .quad 0x00000000
+
+ /* GDT */
+ .balign 16
+entry64_gdt:
+ /* 0x00 unusable segment
+ * 0x08 unused
+ * so use them as gdt ptr
+ */
+ .word gdt_end - entry64_gdt - 1
+ .quad entry64_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:
+
+ .globl kexec_purgatory_code_size
+.set kexec_purgatory_code_size, . - purgatory_entry64
+
+/* Fill rest of the page with zeros to be used as stack */
+stack: .fill purgatory_entry64 + PAGE_SIZE - ., 1, 0
+stack_init:
--
1.7.7.6
