[v7,1/4] powerpc: Refactor kexec functions to move arch independent code to kernel

Message ID	20200930205941.1576-2-nramas@linux.microsoft.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=v9j2=DH=vger.kernel.org=linux-integrity-owner@kernel.org> From: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> To: zohar@linux.ibm.com, bauerman@linux.ibm.com, robh@kernel.org, gregkh@linuxfoundation.org, james.morse@arm.com, catalin.marinas@arm.com, sashal@kernel.org, will@kernel.org, mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, robh+dt@kernel.org, frowand.list@gmail.com, vincenzo.frascino@arm.com, mark.rutland@arm.com, dmitry.kasatkin@gmail.com, jmorris@namei.org, serge@hallyn.com, pasha.tatashin@soleen.com, allison@lohutok.net, kstewart@linuxfoundation.org, takahiro.akashi@linaro.org, tglx@linutronix.de, masahiroy@kernel.org, bhsharma@redhat.com, mbrugger@suse.com, hsinyi@chromium.org, tao.li@vivo.com, christophe.leroy@c-s.fr Cc: linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, prsriva@linux.microsoft.com, balajib@linux.microsoft.com Subject: [PATCH v7 1/4] powerpc: Refactor kexec functions to move arch independent code to kernel Date: Wed, 30 Sep 2020 13:59:38 -0700 Message-Id: <20200930205941.1576-2-nramas@linux.microsoft.com> In-Reply-To: <20200930205941.1576-1-nramas@linux.microsoft.com> References: <20200930205941.1576-1-nramas@linux.microsoft.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	Carry forward IMA measurement log on kexec on ARM64 \| expand [v7,0/3] Carry forward IMA measurement log on kexec on ARM64 [v7,1/4] powerpc: Refactor kexec functions to move arch independent code to kernel [v7,2/4] powerpc: Refactor kexec functions to move arch independent code to ima [v7,3/4] arm64: Store IMA log information in kimage used for kexec [v7,4/4] arm64: Add IMA kexec buffer to DTB

diff --git a/arch/powerpc/include/asm/ima.h b/arch/powerpc/include/asm/ima.h index ead488cf3981..6355a85a3289 100644 --- a/arch/powerpc/include/asm/ima.h +++ b/arch/powerpc/include/asm/ima.h @@ -2,17 +2,13 @@ #ifndef _ASM_POWERPC_IMA_H #define _ASM_POWERPC_IMA_H +#include <linux/kexec.h> + struct kimage; int ima_get_kexec_buffer(void **addr, size_t *size); int ima_free_kexec_buffer(void); -#ifdef CONFIG_IMA -void remove_ima_buffer(void *fdt, int chosen_node); -#else -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); @@ -22,7 +18,7 @@ int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node); static inline int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node) { - remove_ima_buffer(fdt, chosen_node); + remove_ima_kexec_buffer(fdt, chosen_node); return 0; } #endif /* CONFIG_IMA_KEXEC */ diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h index 55d6ede30c19..7c223031ecdd 100644 --- a/arch/powerpc/include/asm/kexec.h +++ b/arch/powerpc/include/asm/kexec.h @@ -126,7 +126,6 @@ int setup_purgatory(struct kimage *image, const void *slave_code, 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); #ifdef CONFIG_PPC64 struct kexec_buf; diff --git a/arch/powerpc/kexec/file_load.c b/arch/powerpc/kexec/file_load.c index 9a232bc36c8f..7a17655c530e 100644 --- a/arch/powerpc/kexec/file_load.c +++ b/arch/powerpc/kexec/file_load.c @@ -18,6 +18,7 @@ #include <linux/kexec.h> #include <linux/of_fdt.h> #include <linux/libfdt.h> +#include <linux/kexec.h> #include <asm/setup.h> #include <asm/ima.h> @@ -109,38 +110,6 @@ int setup_purgatory(struct kimage *image, const void *slave_code, return 0; } -/** - * delete_fdt_mem_rsv - delete memory reservation with given address and size - * - * Return: 0 on success, or negative errno on error. - */ -int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size) -{ - int i, ret, num_rsvs = fdt_num_mem_rsv(fdt); - - for (i = 0; i < num_rsvs; i++) { - uint64_t rsv_start, rsv_size; - - ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size); - if (ret) { - pr_err("Malformed device tree.\n"); - return -EINVAL; - } - - if (rsv_start == start && rsv_size == size) { - ret = fdt_del_mem_rsv(fdt, i); - if (ret) { - pr_err("Error deleting device tree reservation.\n"); - return -EINVAL; - } - - return 0; - } - } - - return -ENOENT; -} - /* * setup_new_fdt - modify /chosen and memory reservation for the next kernel * @image: kexec image being loaded. diff --git a/arch/powerpc/kexec/ima.c b/arch/powerpc/kexec/ima.c index 720e50e490b6..2b790230ea15 100644 --- a/arch/powerpc/kexec/ima.c +++ b/arch/powerpc/kexec/ima.c @@ -11,6 +11,8 @@ #include <linux/of.h> #include <linux/memblock.h> #include <linux/libfdt.h> +#include <linux/ima.h> +#include <asm/ima.h> static int get_addr_size_cells(int *addr_cells, int *size_cells) { @@ -28,24 +30,6 @@ static int get_addr_size_cells(int *addr_cells, int *size_cells) 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. @@ -100,37 +84,14 @@ int ima_free_kexec_buffer(void) } -/** - * 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 * + * @image: kimage struct to set IMA buffer data + * @load_addr: Starting address where IMA buffer is loaded at + * @size: Number of bytes in the IMA buffer + * * Architectures should use this function to pass on the IMA buffer * information to the next kernel. * @@ -179,7 +140,7 @@ 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); + remove_ima_kexec_buffer(fdt, chosen_node); if (!image->arch.ima_buffer_size) return 0; @@ -201,7 +162,7 @@ int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node) if (ret) return ret; - ret = fdt_setprop(fdt, chosen_node, "linux,ima-kexec-buffer", value, + ret = fdt_setprop(fdt, chosen_node, FDT_PROP_IMA_KEXEC_BUFFER, value, entry_size); if (ret < 0) return -EINVAL; diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 9e93bef52968..39a931df6ae4 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -407,6 +407,30 @@ static inline int kexec_crash_loaded(void) { return 0; } #define kexec_in_progress false #endif /* CONFIG_KEXEC_CORE */ +#ifdef CONFIG_HAVE_IMA_KEXEC +extern void remove_ima_kexec_buffer(void *fdt, int chosen_node); +extern int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr, + size_t *size); +#else +static inline void remove_ima_kexec_buffer(void *fdt, int chosen_node) {} +static inline int do_get_kexec_buffer(const void *prop, int len, + unsigned long *addr, size_t *size) +{ + return -EOPNOTSUPP; +} +#endif /* CONFIG_HAVE_IMA_KEXEC */ + +#ifdef CONFIG_KEXEC_FILE +extern int delete_fdt_mem_rsv(void *fdt, unsigned long start, + unsigned long size); +#else +static inline int delete_fdt_mem_rsv(void *fdt, unsigned long start, + unsigned long size) +{ + return 0; +} +#endif /* CONFIG_KEXEC_FILE */ + #endif /* !defined(__ASSEBMLY__) */ #endif /* LINUX_KEXEC_H */ diff --git a/include/linux/libfdt.h b/include/linux/libfdt.h index 90ed4ebfa692..75fb40aa013b 100644 --- a/include/linux/libfdt.h +++ b/include/linux/libfdt.h @@ -5,4 +5,7 @@ #include <linux/libfdt_env.h> #include "../../scripts/dtc/libfdt/libfdt.h" +/* Common device tree properties */ +#define FDT_PROP_IMA_KEXEC_BUFFER "linux,ima-kexec-buffer" + #endif /* _INCLUDE_LIBFDT_H_ */ diff --git a/kernel/Makefile b/kernel/Makefile index 9a20016d4900..f20bb423291a 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -71,8 +71,9 @@ obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o obj-$(CONFIG_CRASH_CORE) += crash_core.o obj-$(CONFIG_KEXEC_CORE) += kexec_core.o obj-$(CONFIG_KEXEC) += kexec.o -obj-$(CONFIG_KEXEC_FILE) += kexec_file.o +obj-$(CONFIG_KEXEC_FILE) += kexec_file.o kexec_file_fdt.o obj-$(CONFIG_KEXEC_ELF) += kexec_elf.o +obj-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o obj-$(CONFIG_BACKTRACE_SELF_TEST) += backtracetest.o obj-$(CONFIG_COMPAT) += compat.o obj-$(CONFIG_CGROUPS) += cgroup/ diff --git a/kernel/ima_kexec.c b/kernel/ima_kexec.c new file mode 100644 index 000000000000..6fb6e4b862aa --- /dev/null +++ b/kernel/ima_kexec.c @@ -0,0 +1,85 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2020 Microsoft Corporation + * + * Author: Lakshmi Ramasubramanian (nramas@linux.microsoft.com) + * + * ima_kexec.c + * Handle IMA buffer for kexec + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/types.h> +#include <linux/err.h> +#include <linux/printk.h> +#include <linux/libfdt.h> +#include <linux/of.h> +#include <linux/kexec.h> + +/** + * do_get_kexec_buffer - Get address and size of IMA kexec buffer + * + * @prop: IMA kexec buffer node in the device tree + * @len: Size of the given device tree node property + * @addr: Return address of the node + * @size: Return size of the node + */ +int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr, + size_t *size) +{ + int addr_cells, 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); + + 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; +} + +/** + * remove_ima_kexec_buffer - remove the IMA buffer property and + * reservation from @fdt + * + * @fdt: Flattened Device Tree to update + * @chosen_node: Offset to the chosen node in the device tree + * + * The IMA measurement buffer is of no use to a subsequent kernel, + * so we always remove it from the device tree. + */ +void remove_ima_kexec_buffer(void *fdt, int chosen_node) +{ + int ret, len; + unsigned long addr; + size_t size; + const void *prop; + + prop = fdt_getprop(fdt, chosen_node, FDT_PROP_IMA_KEXEC_BUFFER, &len); + if (!prop) { + pr_debug("Unable to find the ima kexec buffer node\n"); + return; + } + + ret = do_get_kexec_buffer(prop, len, &addr, &size); + fdt_delprop(fdt, chosen_node, FDT_PROP_IMA_KEXEC_BUFFER); + if (ret) { + pr_err("Unable to delete the ima kexec buffer node\n"); + return; + } + + ret = delete_fdt_mem_rsv(fdt, addr, size); + if (!ret) + pr_debug("Removed old IMA buffer reservation.\n"); +} diff --git a/kernel/kexec_file_fdt.c b/kernel/kexec_file_fdt.c new file mode 100644 index 000000000000..726e43254892 --- /dev/null +++ b/kernel/kexec_file_fdt.c @@ -0,0 +1,55 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2020 Microsoft Corporation + * + * Author: Lakshmi Ramasubramanian (nramas@linux.microsoft.com) + * + * kexec_file_fdt.c + * Handle memory reservation in device tree. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/types.h> +#include <linux/err.h> +#include <linux/printk.h> +#include <linux/libfdt.h> +#include <linux/kexec.h> + +/** + * delete_fdt_mem_rsv - delete memory reservation with given address and size + * + * @fdt: Flattened Device Tree to update + * @start: Starting address of the reservation to delete + * @size: Size of the reservation to delete + * + * Return: 0 on success, or negative errno on error. + */ +int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size) +{ + int i, ret, num_rsvs = fdt_num_mem_rsv(fdt); + + for (i = 0; i < num_rsvs; i++) { + uint64_t rsv_start, rsv_size; + + ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size); + if (ret) { + pr_err("Malformed device tree.\n"); + return -EINVAL; + } + + if (rsv_start == start && rsv_size == size) { + ret = fdt_del_mem_rsv(fdt, i); + if (ret) { + pr_err("Error deleting device tree reservation.\n"); + return -EINVAL; + } + + pr_debug("Freed reserved memory at %lu of size %lu\n", + start, size); + return 0; + } + } + + return -ENOENT; +}

[v7,1/4] powerpc: Refactor kexec functions to move arch independent code to kernel

Commit Message

Comments

Patch