From ab6b1d1fc4aae6b8bd6fb1422405568094c9b40f Mon Sep 17 00:00:00 2001 From: Thiago Jung Bauermann Date: Mon, 19 Dec 2016 16:22:45 -0800 Subject: [PATCH] powerpc: ima: send the kexec buffer to the next kernel The IMA kexec buffer allows the currently running kernel to pass the measurement list via a kexec segment to the kernel that will be kexec'd. This is the architecture-specific part of setting up the IMA kexec buffer for the next kernel. It will be used in the next patch. Link: http://lkml.kernel.org/r/1480554346-29071-6-git-send-email-zohar@linux.vnet.ibm.com Signed-off-by: Thiago Jung Bauermann Signed-off-by: Mimi Zohar Acked-by: "Eric W. Biederman" Cc: Andreas Steffen Cc: Dmitry Kasatkin Cc: Josh Sklar Cc: Dave Young Cc: Vivek Goyal Cc: Baoquan He Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Stewart Smith Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/powerpc/include/asm/ima.h | 16 ++++ arch/powerpc/include/asm/kexec.h | 14 +++- arch/powerpc/kernel/ima_kexec.c | 91 +++++++++++++++++++++ arch/powerpc/kernel/kexec_elf_64.c | 2 +- arch/powerpc/kernel/machine_kexec_file_64.c | 12 ++- 5 files changed, 129 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/include/asm/ima.h b/arch/powerpc/include/asm/ima.h index d5a72dd9b499..2313bdface34 100644 --- a/arch/powerpc/include/asm/ima.h +++ b/arch/powerpc/include/asm/ima.h @@ -1,6 +1,8 @@ #ifndef _ASM_POWERPC_IMA_H #define _ASM_POWERPC_IMA_H +struct kimage; + int ima_get_kexec_buffer(void **addr, size_t *size); int ima_free_kexec_buffer(void); @@ -10,4 +12,18 @@ void remove_ima_buffer(void *fdt, int chosen_node); static inline void remove_ima_buffer(void *fdt, int chosen_node) {} #endif +#ifdef CONFIG_IMA_KEXEC +int arch_ima_add_kexec_buffer(struct kimage *image, unsigned long load_addr, + size_t size); + +int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node); +#else +static inline int setup_ima_buffer(const struct kimage *image, void *fdt, + int chosen_node) +{ + remove_ima_buffer(fdt, chosen_node); + return 0; +} +#endif /* CONFIG_IMA_KEXEC */ + #endif /* _ASM_POWERPC_IMA_H */ diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h index b0fdffb7179b..25668bc8cb2a 100644 --- a/arch/powerpc/include/asm/kexec.h +++ b/arch/powerpc/include/asm/kexec.h @@ -94,11 +94,21 @@ static inline bool kdump_in_progress(void) #ifdef CONFIG_KEXEC_FILE extern struct kexec_file_ops kexec_elf64_ops; +#ifdef CONFIG_IMA_KEXEC +#define ARCH_HAS_KIMAGE_ARCH + +struct kimage_arch { + phys_addr_t ima_buffer_addr; + size_t ima_buffer_size; +}; +#endif + int setup_purgatory(struct kimage *image, const void *slave_code, const void *fdt, unsigned long kernel_load_addr, unsigned long fdt_load_addr); -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 delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size); #endif /* CONFIG_KEXEC_FILE */ diff --git a/arch/powerpc/kernel/ima_kexec.c b/arch/powerpc/kernel/ima_kexec.c index 36e5a5df3804..5ea42c937ca9 100644 --- a/arch/powerpc/kernel/ima_kexec.c +++ b/arch/powerpc/kernel/ima_kexec.c @@ -130,3 +130,94 @@ void remove_ima_buffer(void *fdt, int chosen_node) 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 29331fffad13..992c0d258e5d 100644 --- a/arch/powerpc/kernel/machine_kexec_file_64.c +++ b/arch/powerpc/kernel/machine_kexec_file_64.c @@ -210,6 +210,7 @@ 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. @@ -218,8 +219,9 @@ 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; @@ -329,7 +331,11 @@ int setup_new_fdt(void *fdt, unsigned long initrd_load_addr, } } - remove_ima_buffer(fdt, chosen_node); + 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) { -- 2.20.1