1 files changed, 553 insertions, 0 deletions

diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
new file mode 100644
index 000000000000..9642b9b33655
--- /dev/null
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -0,0 +1,553 @@
+/*
+ * Kexec bzImage loader
+ *
+ * Copyright (C) 2014 Red Hat Inc.
+ * Authors:
+ *      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.
+ */
+
+#define pr_fmt(fmt)     "kexec-bzImage64: " fmt
+
+#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 <linux/efi.h>
+#include <linux/verify_pefile.h>
+#include <keys/system_keyring.h>
+
+#include <asm/bootparam.h>
+#include <asm/setup.h>
+#include <asm/crash.h>
+#include <asm/efi.h>
+
+#define MAX_ELFCOREHDR_STR_LEN  30      /* elfcorehdr=0x<64bit-value> */
+
+/*
+ * Defines lowest physical address for various segments. Not sure where
+ * exactly these limits came from. Current bzimage64 loader in kexec-tools
+ * uses these so I am retaining it. It can be changed over time as we gain
+ * more insight.
+ */
+#define MIN_PURGATORY_ADDR      0x3000
+#define MIN_BOOTPARAM_ADDR      0x3000
+#define MIN_KERNEL_LOAD_ADDR    0x100000
+#define MIN_INITRD_LOAD_ADDR    0x1000000
+
+/*
+ * This is a place holder for all boot loader specific data structure which
+ * gets allocated in one call but gets freed much later during cleanup
+ * time. Right now there is only one field but it can grow as need be.
+ */
+struct bzimage64_data {
+        /*
+         * Temporary buffer to hold bootparams buffer. This should be
+         * freed once the bootparam segment has been loaded.
+         */
+        void *bootparams_buf;
+};
+
+static int setup_initrd(struct boot_params *params,
+                unsigned long initrd_load_addr, unsigned long initrd_len)
+{
+        params->hdr.ramdisk_image = initrd_load_addr & 0xffffffffUL;
+        params->hdr.ramdisk_size = initrd_len & 0xffffffffUL;
+
+        params->ext_ramdisk_image = initrd_load_addr >> 32;
+        params->ext_ramdisk_size = initrd_len >> 32;
+
+        return 0;
+}
+
+static int setup_cmdline(struct kimage *image, struct boot_params *params,
+                         unsigned long bootparams_load_addr,
+                         unsigned long cmdline_offset, char *cmdline,
+                         unsigned long cmdline_len)
+{
+        char *cmdline_ptr = ((char *)params) + cmdline_offset;
+        unsigned long cmdline_ptr_phys, len;
+        uint32_t cmdline_low_32, cmdline_ext_32;
+
+        memcpy(cmdline_ptr, cmdline, cmdline_len);
+        if (image->type == KEXEC_TYPE_CRASH) {
+                len = sprintf(cmdline_ptr + cmdline_len - 1,
+                        " elfcorehdr=0x%lx", image->arch.elf_load_addr);
+                cmdline_len += len;
+        }
+        cmdline_ptr[cmdline_len - 1] = '\0';
+
+        pr_debug("Final command line is: %s\n", cmdline_ptr);
+        cmdline_ptr_phys = bootparams_load_addr + cmdline_offset;
+        cmdline_low_32 = cmdline_ptr_phys & 0xffffffffUL;
+        cmdline_ext_32 = cmdline_ptr_phys >> 32;
+
+        params->hdr.cmd_line_ptr = cmdline_low_32;
+        if (cmdline_ext_32)
+                params->ext_cmd_line_ptr = cmdline_ext_32;
+
+        return 0;
+}
+
+static int setup_e820_entries(struct boot_params *params)
+{
+        unsigned int nr_e820_entries;
+
+        nr_e820_entries = e820_saved.nr_map;
+
+        /* TODO: Pass entries more than E820MAX in bootparams setup data */
+        if (nr_e820_entries > E820MAX)
+                nr_e820_entries = E820MAX;
+
+        params->e820_entries = nr_e820_entries;
+        memcpy(&params->e820_map, &e820_saved.map,
+               nr_e820_entries * sizeof(struct e820entry));
+
+        return 0;
+}
+
+#ifdef CONFIG_EFI
+static int setup_efi_info_memmap(struct boot_params *params,
+                                  unsigned long params_load_addr,
+                                  unsigned int efi_map_offset,
+                                  unsigned int efi_map_sz)
+{
+        void *efi_map = (void *)params + efi_map_offset;
+        unsigned long efi_map_phys_addr = params_load_addr + efi_map_offset;
+        struct efi_info *ei = &params->efi_info;
+
+        if (!efi_map_sz)
+                return 0;
+
+        efi_runtime_map_copy(efi_map, efi_map_sz);
+
+        ei->efi_memmap = efi_map_phys_addr & 0xffffffff;
+        ei->efi_memmap_hi = efi_map_phys_addr >> 32;
+        ei->efi_memmap_size = efi_map_sz;
+
+        return 0;
+}
+
+static int
+prepare_add_efi_setup_data(struct boot_params *params,
+                       unsigned long params_load_addr,
+                       unsigned int efi_setup_data_offset)
+{
+        unsigned long setup_data_phys;
+        struct setup_data *sd = (void *)params + efi_setup_data_offset;
+        struct efi_setup_data *esd = (void *)sd + sizeof(struct setup_data);
+
+        esd->fw_vendor = efi.fw_vendor;
+        esd->runtime = efi.runtime;
+        esd->tables = efi.config_table;
+        esd->smbios = efi.smbios;
+
+        sd->type = SETUP_EFI;
+        sd->len = sizeof(struct efi_setup_data);
+
+        /* Add setup data */
+        setup_data_phys = params_load_addr + efi_setup_data_offset;
+        sd->next = params->hdr.setup_data;
+        params->hdr.setup_data = setup_data_phys;
+
+        return 0;
+}
+
+static int
+setup_efi_state(struct boot_params *params, unsigned long params_load_addr,
+                unsigned int efi_map_offset, unsigned int efi_map_sz,
+                unsigned int efi_setup_data_offset)
+{
+        struct efi_info *current_ei = &boot_params.efi_info;
+        struct efi_info *ei = &params->efi_info;
+
+        if (!current_ei->efi_memmap_size)
+                return 0;
+
+        /*
+         * If 1:1 mapping is not enabled, second kernel can not setup EFI
+         * and use EFI run time services. User space will have to pass
+         * acpi_rsdp=<addr> on kernel command line to make second kernel boot
+         * without efi.
+         */
+        if (efi_enabled(EFI_OLD_MEMMAP))
+                return 0;
+
+        ei->efi_loader_signature = current_ei->efi_loader_signature;
+        ei->efi_systab = current_ei->efi_systab;
+        ei->efi_systab_hi = current_ei->efi_systab_hi;
+
+        ei->efi_memdesc_version = current_ei->efi_memdesc_version;
+        ei->efi_memdesc_size = efi_get_runtime_map_desc_size();
+
+        setup_efi_info_memmap(params, params_load_addr, efi_map_offset,
+                              efi_map_sz);
+        prepare_add_efi_setup_data(params, params_load_addr,
+                                   efi_setup_data_offset);
+        return 0;
+}
+#endif /* CONFIG_EFI */
+
+static int
+setup_boot_parameters(struct kimage *image, struct boot_params *params,
+                      unsigned long params_load_addr,
+                      unsigned int efi_map_offset, unsigned int efi_map_sz,
+                      unsigned int efi_setup_data_offset)
+{
+        unsigned int nr_e820_entries;
+        unsigned long long mem_k, start, end;
+        int i, ret = 0;
+
+        /* Get subarch from existing bootparams */
+        params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch;
+
+        /* Copying screen_info will do? */
+        memcpy(&params->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(&params->apm_bios_info, 0, sizeof(params->apm_bios_info));
+
+        /* Default drive info */
+        memset(&params->hd0_info, 0, sizeof(params->hd0_info));
+        memset(&params->hd1_info, 0, sizeof(params->hd1_info));
+
+        /* Default sysdesc table */
+        params->sys_desc_table.length = 0;
+
+        if (image->type == KEXEC_TYPE_CRASH) {
+                ret = crash_setup_memmap_entries(image, params);
+                if (ret)
+                        return ret;
+        } else
+                setup_e820_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;
+                }
+        }
+
+#ifdef CONFIG_EFI
+        /* Setup EFI state */
+        setup_efi_state(params, params_load_addr, efi_map_offset, efi_map_sz,
+                        efi_setup_data_offset);
+#endif
+
+        /* 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));
+
+        return ret;
+}
+
+int bzImage64_probe(const char *buf, unsigned long len)
+{
+        int ret = -ENOEXEC;
+        struct setup_header *header;
+
+        /* kernel should be atleast two sectors long */
+        if (len < 2 * 512) {
+                pr_err("File is too short to be a bzImage\n");
+                return ret;
+        }
+
+        header = (struct setup_header *)(buf + offsetof(struct boot_params, hdr));
+        if (memcmp((char *)&header->header, "HdrS", 4) != 0) {
+                pr_err("Not a bzImage\n");
+                return ret;
+        }
+
+        if (header->boot_flag != 0xAA55) {
+                pr_err("No x86 boot sector present\n");
+                return ret;
+        }
+
+        if (header->version < 0x020C) {
+                pr_err("Must be at least protocol version 2.12\n");
+                return ret;
+        }
+
+        if (!(header->loadflags & LOADED_HIGH)) {
+                pr_err("zImage not a bzImage\n");
+                return ret;
+        }
+
+        if (!(header->xloadflags & XLF_KERNEL_64)) {
+                pr_err("Not a bzImage64. XLF_KERNEL_64 is not set.\n");
+                return ret;
+        }
+
+        if (!(header->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G)) {
+                pr_err("XLF_CAN_BE_LOADED_ABOVE_4G is not set.\n");
+                return ret;
+        }
+
+        /*
+         * Can't handle 32bit EFI as it does not allow loading kernel
+         * above 4G. This should be handled by 32bit bzImage loader
+         */
+        if (efi_enabled(EFI_RUNTIME_SERVICES) && !efi_enabled(EFI_64BIT)) {
+                pr_debug("EFI is 32 bit. Can't load kernel above 4G.\n");
+                return ret;
+        }
+
+        /* I've got a bzImage */
+        pr_debug("It's a relocatable bzImage64\n");
+        ret = 0;
+
+        return ret;
+}
+
+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, ret = 0;
+        unsigned long setup_header_size, params_cmdline_sz, params_misc_sz;
+        struct boot_params *params;
+        unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr;
+        unsigned long purgatory_load_addr;
+        unsigned long kernel_bufsz, kernel_memsz, kernel_align;
+        char *kernel_buf;
+        struct bzimage64_data *ldata;
+        struct kexec_entry64_regs regs64;
+        void *stack;
+        unsigned int setup_hdr_offset = offsetof(struct boot_params, hdr);
+        unsigned int efi_map_offset, efi_map_sz, efi_setup_data_offset;
+
+        header = (struct setup_header *)(kernel + setup_hdr_offset);
+        setup_sects = header->setup_sects;
+        if (setup_sects == 0)
+                setup_sects = 4;
+
+        kern16_size = (setup_sects + 1) * 512;
+        if (kernel_len < kern16_size) {
+                pr_err("bzImage truncated\n");
+                return ERR_PTR(-ENOEXEC);
+        }
+
+        if (cmdline_len > header->cmdline_size) {
+                pr_err("Kernel command line too long\n");
+                return ERR_PTR(-EINVAL);
+        }
+
+        /*
+         * In case of crash dump, we will append elfcorehdr=<addr> to
+         * command line. Make sure it does not overflow
+         */
+        if (cmdline_len + MAX_ELFCOREHDR_STR_LEN > header->cmdline_size) {
+                pr_debug("Appending elfcorehdr=<addr> to command line exceeds maximum allowed length\n");
+                return ERR_PTR(-EINVAL);
+        }
+
+        /* Allocate and load backup region */
+        if (image->type == KEXEC_TYPE_CRASH) {
+                ret = crash_load_segments(image);
+                if (ret)
+                        return ERR_PTR(ret);
+        }
+
+        /*
+         * Load purgatory. For 64bit entry point, purgatory  code can be
+         * anywhere.
+         */
+        ret = kexec_load_purgatory(image, MIN_PURGATORY_ADDR, ULONG_MAX, 1,
+                                   &purgatory_load_addr);
+        if (ret) {
+                pr_err("Loading purgatory failed\n");
+                return ERR_PTR(ret);
+        }
+
+        pr_debug("Loaded purgatory at 0x%lx\n", purgatory_load_addr);
+
+
+        /*
+         * Load Bootparams and cmdline and space for efi stuff.
+         *
+         * Allocate memory together for multiple data structures so
+         * that they all can go in single area/segment and we don't
+         * have to create separate segment for each. Keeps things
+         * little bit simple
+         */
+        efi_map_sz = efi_get_runtime_map_size();
+        efi_map_sz = ALIGN(efi_map_sz, 16);
+        params_cmdline_sz = sizeof(struct boot_params) + cmdline_len +
+                                MAX_ELFCOREHDR_STR_LEN;
+        params_cmdline_sz = ALIGN(params_cmdline_sz, 16);
+        params_misc_sz = params_cmdline_sz + efi_map_sz +
+                                sizeof(struct setup_data) +
+                                sizeof(struct efi_setup_data);
+
+        params = kzalloc(params_misc_sz, GFP_KERNEL);
+        if (!params)
+                return ERR_PTR(-ENOMEM);
+        efi_map_offset = params_cmdline_sz;
+        efi_setup_data_offset = efi_map_offset + efi_map_sz;
+
+        /* Copy setup header onto bootparams. Documentation/x86/boot.txt */
+        setup_header_size = 0x0202 + kernel[0x0201] - setup_hdr_offset;
+
+        /* Is there a limit on setup header size? */
+        memcpy(&params->hdr, (kernel + setup_hdr_offset), setup_header_size);
+
+        ret = kexec_add_buffer(image, (char *)params, params_misc_sz,
+                               params_misc_sz, 16, MIN_BOOTPARAM_ADDR,
+                               ULONG_MAX, 1, &bootparam_load_addr);
+        if (ret)
+                goto out_free_params;
+        pr_debug("Loaded boot_param, command line and misc at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
+                 bootparam_load_addr, params_misc_sz, params_misc_sz);
+
+        /* Load kernel */
+        kernel_buf = kernel + kern16_size;
+        kernel_bufsz =  kernel_len - kern16_size;
+        kernel_memsz = PAGE_ALIGN(header->init_size);
+        kernel_align = header->kernel_alignment;
+
+        ret = kexec_add_buffer(image, kernel_buf,
+                               kernel_bufsz, kernel_memsz, kernel_align,
+                               MIN_KERNEL_LOAD_ADDR, ULONG_MAX, 1,
+                               &kernel_load_addr);
+        if (ret)
+                goto out_free_params;
+
+        pr_debug("Loaded 64bit kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
+                 kernel_load_addr, kernel_memsz, kernel_memsz);
+
+        /* Load initrd high */
+        if (initrd) {
+                ret = kexec_add_buffer(image, initrd, initrd_len, initrd_len,
+                                       PAGE_SIZE, MIN_INITRD_LOAD_ADDR,
+                                       ULONG_MAX, 1, &initrd_load_addr);
+                if (ret)
+                        goto out_free_params;
+
+                pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
+                                initrd_load_addr, initrd_len, initrd_len);
+
+                setup_initrd(params, initrd_load_addr, initrd_len);
+        }
+
+        setup_cmdline(image, params, bootparam_load_addr,
+                      sizeof(struct boot_params), 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 purgatory regs for entry */
+        ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", &regs64,
+                                             sizeof(regs64), 1);
+        if (ret)
+                goto out_free_params;
+
+        regs64.rbx = 0; /* Bootstrap Processor */
+        regs64.rsi = bootparam_load_addr;
+        regs64.rip = kernel_load_addr + 0x200;
+        stack = kexec_purgatory_get_symbol_addr(image, "stack_end");
+        if (IS_ERR(stack)) {
+                pr_err("Could not find address of symbol stack_end\n");
+                ret = -EINVAL;
+                goto out_free_params;
+        }
+
+        regs64.rsp = (unsigned long)stack;
+        ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", &regs64,
+                                             sizeof(regs64), 0);
+        if (ret)
+                goto out_free_params;
+
+        ret = setup_boot_parameters(image, params, bootparam_load_addr,
+                                    efi_map_offset, efi_map_sz,
+                                    efi_setup_data_offset);
+        if (ret)
+                goto out_free_params;
+
+        /* Allocate loader specific data */
+        ldata = kzalloc(sizeof(struct bzimage64_data), GFP_KERNEL);
+        if (!ldata) {
+                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;
+        return ldata;
+
+out_free_params:
+        kfree(params);
+        return ERR_PTR(ret);
+}
+
+/* This cleanup function is called after various segments have been loaded */
+int bzImage64_cleanup(void *loader_data)
+{
+        struct bzimage64_data *ldata = loader_data;
+
+        if (!ldata)
+                return 0;
+
+        kfree(ldata->bootparams_buf);
+        ldata->bootparams_buf = NULL;
+
+        return 0;
+}
+
+#ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
+int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len)
+{
+        bool trusted;
+        int ret;
+
+        ret = verify_pefile_signature(kernel, kernel_len,
+                                      system_trusted_keyring, &trusted);
+        if (ret < 0)
+                return ret;
+        if (!trusted)
+                return -EKEYREJECTED;
+        return 0;
+}
+#endif
+
+struct kexec_file_ops kexec_bzImage64_ops = {
+        .probe = bzImage64_probe,
+        .load = bzImage64_load,
+        .cleanup = bzImage64_cleanup,
+#ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
+        .verify_sig = bzImage64_verify_sig,
+#endif
+};