diff options
Diffstat (limited to 'arch/powerpc/kernel')
| -rw-r--r-- | arch/powerpc/kernel/Makefile | 4 | ||||
| -rw-r--r-- | arch/powerpc/kernel/ima_kexec.c | 223 | ||||
| -rw-r--r-- | arch/powerpc/kernel/kexec_elf_64.c | 2 | ||||
| -rw-r--r-- | arch/powerpc/kernel/machine_kexec_file_64.c | 15 |
4 files changed, 240 insertions, 4 deletions
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index a3a6047fd395..23f8082d7bfa 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -112,6 +112,10 @@ obj-$(CONFIG_PCI_MSI) += msi.o obj-$(CONFIG_KEXEC_CORE) += machine_kexec.o crash.o \ machine_kexec_$(BITS).o obj-$(CONFIG_KEXEC_FILE) += machine_kexec_file_$(BITS).o kexec_elf_$(BITS).o +ifeq ($(CONFIG_HAVE_IMA_KEXEC)$(CONFIG_IMA),yy) +obj-y += ima_kexec.o +endif + obj-$(CONFIG_AUDIT) += audit.o obj64-$(CONFIG_AUDIT) += compat_audit.o diff --git a/arch/powerpc/kernel/ima_kexec.c b/arch/powerpc/kernel/ima_kexec.c new file mode 100644 index 000000000000..5ea42c937ca9 --- /dev/null +++ b/arch/powerpc/kernel/ima_kexec.c @@ -0,0 +1,223 @@ +/* + * Copyright (C) 2016 IBM Corporation + * + * Authors: + * Thiago Jung Bauermann <bauerman@linux.vnet.ibm.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; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <linux/slab.h> +#include <linux/kexec.h> +#include <linux/of.h> +#include <linux/memblock.h> +#include <linux/libfdt.h> + +static int get_addr_size_cells(int *addr_cells, int *size_cells) +{ + struct device_node *root; + + root = of_find_node_by_path("/"); + if (!root) + return -EINVAL; + + *addr_cells = of_n_addr_cells(root); + *size_cells = of_n_size_cells(root); + + of_node_put(root); + + return 0; +} + +static int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr, + size_t *size) +{ + int ret, addr_cells, size_cells; + + ret = get_addr_size_cells(&addr_cells, &size_cells); + if (ret) + return ret; + + if (len < 4 * (addr_cells + size_cells)) + return -ENOENT; + + *addr = of_read_number(prop, addr_cells); + *size = of_read_number(prop + 4 * addr_cells, size_cells); + + return 0; +} + +/** + * ima_get_kexec_buffer - get IMA buffer from the previous kernel + * @addr: On successful return, set to point to the buffer contents. + * @size: On successful return, set to the buffer size. + * + * Return: 0 on success, negative errno on error. + */ +int ima_get_kexec_buffer(void **addr, size_t *size) +{ + int ret, len; + unsigned long tmp_addr; + size_t tmp_size; + const void *prop; + + prop = of_get_property(of_chosen, "linux,ima-kexec-buffer", &len); + if (!prop) + return -ENOENT; + + ret = do_get_kexec_buffer(prop, len, &tmp_addr, &tmp_size); + if (ret) + return ret; + + *addr = __va(tmp_addr); + *size = tmp_size; + + return 0; +} + +/** + * ima_free_kexec_buffer - free memory used by the IMA buffer + */ +int ima_free_kexec_buffer(void) +{ + int ret; + unsigned long addr; + size_t size; + struct property *prop; + + prop = of_find_property(of_chosen, "linux,ima-kexec-buffer", NULL); + if (!prop) + return -ENOENT; + + ret = do_get_kexec_buffer(prop->value, prop->length, &addr, &size); + if (ret) + return ret; + + ret = of_remove_property(of_chosen, prop); + if (ret) + return ret; + + return memblock_free(addr, size); + +} + +/** + * remove_ima_buffer - remove the IMA buffer property and reservation from @fdt + * + * The IMA measurement buffer is of no use to a subsequent kernel, so we always + * remove it from the device tree. + */ +void remove_ima_buffer(void *fdt, int chosen_node) +{ + int ret, len; + unsigned long addr; + size_t size; + const void *prop; + + prop = fdt_getprop(fdt, chosen_node, "linux,ima-kexec-buffer", &len); + if (!prop) + return; + + ret = do_get_kexec_buffer(prop, len, &addr, &size); + fdt_delprop(fdt, chosen_node, "linux,ima-kexec-buffer"); + if (ret) + return; + + ret = delete_fdt_mem_rsv(fdt, addr, size); + if (!ret) + pr_debug("Removed old IMA buffer reservation.\n"); +} + +#ifdef CONFIG_IMA_KEXEC +/** + * arch_ima_add_kexec_buffer - do arch-specific steps to add the IMA buffer + * + * Architectures should use this function to pass on the IMA buffer + * information to the next kernel. + * + * Return: 0 on success, negative errno on error. + */ +int arch_ima_add_kexec_buffer(struct kimage *image, unsigned long load_addr, + size_t size) +{ + image->arch.ima_buffer_addr = load_addr; + image->arch.ima_buffer_size = size; + + return 0; +} + +static int write_number(void *p, u64 value, int cells) +{ + if (cells == 1) { + u32 tmp; + + if (value > U32_MAX) + return -EINVAL; + + tmp = cpu_to_be32(value); + memcpy(p, &tmp, sizeof(tmp)); + } else if (cells == 2) { + u64 tmp; + + tmp = cpu_to_be64(value); + memcpy(p, &tmp, sizeof(tmp)); + } else + return -EINVAL; + + return 0; +} + +/** + * setup_ima_buffer - add IMA buffer information to the fdt + * @image: kexec image being loaded. + * @fdt: Flattened device tree for the next kernel. + * @chosen_node: Offset to the chosen node. + * + * Return: 0 on success, or negative errno on error. + */ +int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node) +{ + int ret, addr_cells, size_cells, entry_size; + u8 value[16]; + + remove_ima_buffer(fdt, chosen_node); + if (!image->arch.ima_buffer_size) + return 0; + + ret = get_addr_size_cells(&addr_cells, &size_cells); + if (ret) + return ret; + + entry_size = 4 * (addr_cells + size_cells); + + if (entry_size > sizeof(value)) + return -EINVAL; + + ret = write_number(value, image->arch.ima_buffer_addr, addr_cells); + if (ret) + return ret; + + ret = write_number(value + 4 * addr_cells, image->arch.ima_buffer_size, + size_cells); + if (ret) + return ret; + + ret = fdt_setprop(fdt, chosen_node, "linux,ima-kexec-buffer", value, + entry_size); + if (ret < 0) + return -EINVAL; + + ret = fdt_add_mem_rsv(fdt, image->arch.ima_buffer_addr, + image->arch.ima_buffer_size); + if (ret) + return -EINVAL; + + pr_debug("IMA buffer at 0x%llx, size = 0x%zx\n", + image->arch.ima_buffer_addr, image->arch.ima_buffer_size); + + return 0; +} +#endif /* CONFIG_IMA_KEXEC */ diff --git a/arch/powerpc/kernel/kexec_elf_64.c b/arch/powerpc/kernel/kexec_elf_64.c index 6acffd34a70f..9a42309b091a 100644 --- a/arch/powerpc/kernel/kexec_elf_64.c +++ b/arch/powerpc/kernel/kexec_elf_64.c @@ -627,7 +627,7 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, goto out; } - ret = setup_new_fdt(fdt, initrd_load_addr, initrd_len, cmdline); + ret = setup_new_fdt(image, fdt, initrd_load_addr, initrd_len, cmdline); if (ret) goto out; diff --git a/arch/powerpc/kernel/machine_kexec_file_64.c b/arch/powerpc/kernel/machine_kexec_file_64.c index 7abc8a75ee48..992c0d258e5d 100644 --- a/arch/powerpc/kernel/machine_kexec_file_64.c +++ b/arch/powerpc/kernel/machine_kexec_file_64.c @@ -27,6 +27,7 @@ #include <linux/memblock.h> #include <linux/of_fdt.h> #include <linux/libfdt.h> +#include <asm/ima.h> #define SLAVE_CODE_SIZE 256 @@ -180,7 +181,7 @@ int setup_purgatory(struct kimage *image, const void *slave_code, * * Return: 0 on success, or negative errno on error. */ -static int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size) +int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size) { int i, ret, num_rsvs = fdt_num_mem_rsv(fdt); @@ -209,6 +210,7 @@ static int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size /* * setup_new_fdt - modify /chosen and memory reservation for the next kernel + * @image: kexec image being loaded. * @fdt: Flattened device tree for the next kernel. * @initrd_load_addr: Address where the next initrd will be loaded. * @initrd_len: Size of the next initrd, or 0 if there will be none. @@ -217,8 +219,9 @@ static int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size * * Return: 0 on success, or negative errno on error. */ -int setup_new_fdt(void *fdt, unsigned long initrd_load_addr, - unsigned long initrd_len, const char *cmdline) +int setup_new_fdt(const struct kimage *image, void *fdt, + unsigned long initrd_load_addr, unsigned long initrd_len, + const char *cmdline) { int ret, chosen_node; const void *prop; @@ -328,6 +331,12 @@ int setup_new_fdt(void *fdt, unsigned long initrd_load_addr, } } + ret = setup_ima_buffer(image, fdt, chosen_node); + if (ret) { + pr_err("Error setting up the new device tree.\n"); + return ret; + } + ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0); if (ret) { pr_err("Error setting up the new device tree.\n"); |