--- v6
+++ v15
@@ -1,116 +1,304 @@
-Address and size of the buffer containing the IMA measurement log need
-to be passed from the current kernel to the next kernel on kexec.
-
-Add address and size fields to "struct kimage_arch" for ARM64 platform
-to hold the address and size of the IMA measurement log buffer.
-Define an architecture specific function for ARM64 namely
-arch_ima_add_kexec_buffer() that will set the address and size of
-the current kernel's IMA buffer to be passed to the next kernel on kexec.
-
-Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
-Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
-Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
-Reported-by: kernel test robot <lkp@intel.com> warning: no previous prototype for 'arch_ima_add_kexec_buffer' [-Wmissing-prototypes]
+From: Rob Herring <robh@kernel.org>
+
+Both arm64 and powerpc do essentially the same FDT /chosen setup for
+kexec. The differences are either omissions that arm64 should have
+or additional properties that will be ignored. The setup code can be
+combined and shared by both powerpc and arm64.
+
+The differences relative to the arm64 version:
+ - If /chosen doesn't exist, it will be created (should never happen).
+ - Any old dtb and initrd reserved memory will be released.
+ - The new initrd and elfcorehdr are marked reserved.
+ - "linux,booted-from-kexec" is set.
+
+The differences relative to the powerpc version:
+ - "kaslr-seed" and "rng-seed" may be set.
+ - "linux,elfcorehdr" is set.
+ - Any existing "linux,usable-memory-range" is removed.
+
+Combine the code for setting up the /chosen node in the FDT and updating
+the memory reservation for kexec, for powerpc and arm64, in
+of_kexec_setup_new_fdt() and move it to "drivers/of/kexec.c".
+
+Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
+Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
---
- arch/arm64/include/asm/ima.h | 18 ++++++++++++++++++
- arch/arm64/include/asm/kexec.h | 3 +++
- arch/arm64/kernel/Makefile | 1 +
- arch/arm64/kernel/ima_kexec.c | 34 ++++++++++++++++++++++++++++++++++
- 4 files changed, 56 insertions(+)
- create mode 100644 arch/arm64/include/asm/ima.h
- create mode 100644 arch/arm64/kernel/ima_kexec.c
-
-diff --git a/arch/arm64/include/asm/ima.h b/arch/arm64/include/asm/ima.h
+ drivers/of/Makefile | 1 +
+ drivers/of/kexec.c | 236 ++++++++++++++++++++++++++++++++++++++++++++
+ include/linux/of.h | 5 +
+ 3 files changed, 242 insertions(+)
+ create mode 100644 drivers/of/kexec.c
+
+diff --git a/drivers/of/Makefile b/drivers/of/Makefile
+index 6e1e5212f058..8ce11955afde 100644
+--- a/drivers/of/Makefile
++++ b/drivers/of/Makefile
+@@ -13,5 +13,6 @@ obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o
+ obj-$(CONFIG_OF_RESOLVE) += resolver.o
+ obj-$(CONFIG_OF_OVERLAY) += overlay.o
+ obj-$(CONFIG_OF_NUMA) += of_numa.o
++obj-$(CONFIG_KEXEC_FILE) += kexec.o
+
+ obj-$(CONFIG_OF_UNITTEST) += unittest-data/
+diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
new file mode 100644
-index 000000000000..507fc94ddaba
+index 000000000000..4afd3cc1c04a
--- /dev/null
-+++ b/arch/arm64/include/asm/ima.h
-@@ -0,0 +1,18 @@
-+/* SPDX-License-Identifier: GPL-2.0-or-later */
++++ b/drivers/of/kexec.c
+@@ -0,0 +1,236 @@
++// SPDX-License-Identifier: GPL-2.0-only
+/*
-+ * Copyright (C) 2019 Microsoft Corporation
-+ *
-+ * Author: Prakhar Srivastava <prsriva@linux.microsoft.com>
-+ *
-+ */
-+#ifndef _ASM_ARCH_IMA_H
-+#define _ASM_ARCH_IMA_H
-+
-+struct kimage;
-+
-+#ifdef CONFIG_IMA_KEXEC
-+int arch_ima_add_kexec_buffer(struct kimage *image, unsigned long load_addr,
-+ size_t size);
-+#endif /* CONFIG_IMA_KEXEC */
-+
-+#endif /* _ASM_ARCH_IMA_H */
-diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
-index d24b527e8c00..7bd60c185ad3 100644
---- a/arch/arm64/include/asm/kexec.h
-+++ b/arch/arm64/include/asm/kexec.h
-@@ -100,6 +100,9 @@ struct kimage_arch {
- void *elf_headers;
- unsigned long elf_headers_mem;
- unsigned long elf_headers_sz;
-+
-+ phys_addr_t ima_buffer_addr;
-+ size_t ima_buffer_size;
- };
-
- extern const struct kexec_file_ops kexec_image_ops;
-diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
-index a561cbb91d4d..39c5d99b49fc 100644
---- a/arch/arm64/kernel/Makefile
-+++ b/arch/arm64/kernel/Makefile
-@@ -62,6 +62,7 @@ obj-$(CONFIG_ARM_SDE_INTERFACE) += sdei.o
- obj-$(CONFIG_ARM64_SSBD) += ssbd.o
- obj-$(CONFIG_ARM64_PTR_AUTH) += pointer_auth.o
- obj-$(CONFIG_SHADOW_CALL_STACK) += scs.o
-+obj-$(CONFIG_IMA_KEXEC) += ima_kexec.o
-
- obj-y += vdso/ probes/
- obj-$(CONFIG_COMPAT_VDSO) += vdso32/
-diff --git a/arch/arm64/kernel/ima_kexec.c b/arch/arm64/kernel/ima_kexec.c
-new file mode 100644
-index 000000000000..1847f1230710
---- /dev/null
-+++ b/arch/arm64/kernel/ima_kexec.c
-@@ -0,0 +1,34 @@
-+// SPDX-License-Identifier: GPL-2.0-or-later
-+/*
-+ * Copyright (C) 2019 Microsoft Corporation
-+ *
-+ * Author: Prakhar Srivastava <prsriva@linux.microsoft.com>
-+ *
-+ * File: ima_kexec.c
-+ * Defines IMA kexec functions.
++ * Copyright (C) 2020 Arm Limited
++ *
++ * Based on arch/arm64/kernel/machine_kexec_file.c:
++ * Copyright (C) 2018 Linaro Limited
++ *
++ * And arch/powerpc/kexec/file_load.c:
++ * Copyright (C) 2016 IBM Corporation
+ */
+
+#include <linux/kernel.h>
+#include <linux/kexec.h>
++#include <linux/libfdt.h>
++#include <linux/of.h>
++#include <linux/of_fdt.h>
++#include <linux/random.h>
+#include <linux/types.h>
-+#include <asm/ima.h>
++
++/* relevant device tree properties */
++#define FDT_PROP_KEXEC_ELFHDR "linux,elfcorehdr"
++#define FDT_PROP_MEM_RANGE "linux,usable-memory-range"
++#define FDT_PROP_INITRD_START "linux,initrd-start"
++#define FDT_PROP_INITRD_END "linux,initrd-end"
++#define FDT_PROP_BOOTARGS "bootargs"
++#define FDT_PROP_KASLR_SEED "kaslr-seed"
++#define FDT_PROP_RNG_SEED "rng-seed"
++#define RNG_SEED_SIZE 128
+
+/**
-+ * arch_ima_add_kexec_buffer - do arch-specific steps to add the IMA buffer
-+ *
-+ * @image: kimage structure to set ima buffer information in for kexec
-+ * @load_addr: Start address of the IMA buffer
-+ * @size: size of 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.
++ * fdt_find_and_del_mem_rsv - delete memory reservation with given address and size
++ *
++ * @fdt: Flattened device tree for the current kernel.
++ * @start: Starting address of the reserved memory.
++ * @size: Size of the reserved memory.
++ *
++ * Return: 0 on success, or negative errno on error.
+ */
-+int arch_ima_add_kexec_buffer(struct kimage *image, unsigned long load_addr,
-+ size_t size)
++static int fdt_find_and_del_mem_rsv(void *fdt, unsigned long start, unsigned long size)
+{
-+ image->arch.ima_buffer_addr = load_addr;
-+ image->arch.ima_buffer_size = size;
++ int i, ret, num_rsvs = fdt_num_mem_rsv(fdt);
++
++ for (i = 0; i < num_rsvs; i++) {
++ u64 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;
++}
++
++/*
++ * of_kexec_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.
++ * @cmdline: Command line for the next kernel, or NULL if there will
++ * be none.
++ *
++ * Return: 0 on success, or negative errno on error.
++ */
++int of_kexec_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;
++
++ /* Remove memory reservation for the current device tree. */
++ ret = fdt_find_and_del_mem_rsv(fdt, __pa(initial_boot_params),
++ fdt_totalsize(initial_boot_params));
++ if (ret == -EINVAL)
++ return ret;
++
++ chosen_node = fdt_path_offset(fdt, "/chosen");
++ if (chosen_node == -FDT_ERR_NOTFOUND)
++ chosen_node = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"),
++ "chosen");
++ if (chosen_node < 0) {
++ ret = chosen_node;
++ goto out;
++ }
++
++ ret = fdt_delprop(fdt, chosen_node, FDT_PROP_KEXEC_ELFHDR);
++ if (ret && ret != -FDT_ERR_NOTFOUND)
++ goto out;
++ ret = fdt_delprop(fdt, chosen_node, FDT_PROP_MEM_RANGE);
++ if (ret && ret != -FDT_ERR_NOTFOUND)
++ goto out;
++
++ /* Did we boot using an initrd? */
++ prop = fdt_getprop(fdt, chosen_node, "linux,initrd-start", NULL);
++ if (prop) {
++ u64 tmp_start, tmp_end, tmp_size;
++
++ tmp_start = fdt64_to_cpu(*((const fdt64_t *) prop));
++
++ prop = fdt_getprop(fdt, chosen_node, "linux,initrd-end", NULL);
++ if (!prop)
++ return -EINVAL;
++
++ tmp_end = fdt64_to_cpu(*((const fdt64_t *) prop));
++
++ /*
++ * kexec reserves exact initrd size, while firmware may
++ * reserve a multiple of PAGE_SIZE, so check for both.
++ */
++ tmp_size = tmp_end - tmp_start;
++ ret = fdt_find_and_del_mem_rsv(fdt, tmp_start, tmp_size);
++ if (ret == -ENOENT)
++ ret = fdt_find_and_del_mem_rsv(fdt, tmp_start,
++ round_up(tmp_size, PAGE_SIZE));
++ if (ret == -EINVAL)
++ return ret;
++ }
++
++ /* add initrd-* */
++ if (initrd_load_addr) {
++ ret = fdt_setprop_u64(fdt, chosen_node, FDT_PROP_INITRD_START,
++ initrd_load_addr);
++ if (ret)
++ goto out;
++
++ ret = fdt_setprop_u64(fdt, chosen_node, FDT_PROP_INITRD_END,
++ initrd_load_addr + initrd_len);
++ if (ret)
++ goto out;
++
++ ret = fdt_add_mem_rsv(fdt, initrd_load_addr, initrd_len);
++ if (ret)
++ goto out;
++
++ } else {
++ ret = fdt_delprop(fdt, chosen_node, FDT_PROP_INITRD_START);
++ if (ret && (ret != -FDT_ERR_NOTFOUND))
++ goto out;
++
++ ret = fdt_delprop(fdt, chosen_node, FDT_PROP_INITRD_END);
++ if (ret && (ret != -FDT_ERR_NOTFOUND))
++ goto out;
++ }
++
++ if (image->type == KEXEC_TYPE_CRASH) {
++ /* add linux,elfcorehdr */
++ ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
++ FDT_PROP_KEXEC_ELFHDR,
++ image->arch.elf_headers_mem,
++ image->arch.elf_headers_sz);
++ if (ret)
++ goto out;
++
++ /*
++ * Avoid elfcorehdr from being stomped on in kdump kernel by
++ * setting up memory reserve map.
++ */
++ ret = fdt_add_mem_rsv(fdt, image->arch.elf_headers_mem,
++ image->arch.elf_headers_sz);
++ if (ret)
++ goto out;
++
++ /* add linux,usable-memory-range */
++ ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
++ FDT_PROP_MEM_RANGE,
++ crashk_res.start,
++ crashk_res.end - crashk_res.start + 1);
++ if (ret)
++ goto out;
++ }
++
++ /* add bootargs */
++ if (cmdline) {
++ ret = fdt_setprop_string(fdt, chosen_node, FDT_PROP_BOOTARGS, cmdline);
++ if (ret)
++ goto out;
++ } else {
++ ret = fdt_delprop(fdt, chosen_node, FDT_PROP_BOOTARGS);
++ if (ret && (ret != -FDT_ERR_NOTFOUND))
++ goto out;
++ }
++
++ /* add kaslr-seed */
++ ret = fdt_delprop(fdt, chosen_node, FDT_PROP_KASLR_SEED);
++ if (ret == -FDT_ERR_NOTFOUND)
++ ret = 0;
++ else if (ret)
++ goto out;
++
++ if (rng_is_initialized()) {
++ u64 seed = get_random_u64();
++
++ ret = fdt_setprop_u64(fdt, chosen_node, FDT_PROP_KASLR_SEED, seed);
++ if (ret)
++ goto out;
++ } else {
++ pr_notice("RNG is not initialised: omitting \"%s\" property\n",
++ FDT_PROP_KASLR_SEED);
++ }
++
++ /* add rng-seed */
++ if (rng_is_initialized()) {
++ void *rng_seed;
++
++ ret = fdt_setprop_placeholder(fdt, chosen_node, FDT_PROP_RNG_SEED,
++ RNG_SEED_SIZE, &rng_seed);
++ if (ret)
++ goto out;
++ get_random_bytes(rng_seed, RNG_SEED_SIZE);
++ } else {
++ pr_notice("RNG is not initialised: omitting \"%s\" property\n",
++ FDT_PROP_RNG_SEED);
++ }
++
++ ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0);
++
++out:
++ if (ret)
++ return (ret == -FDT_ERR_NOSPACE) ? -ENOMEM : -EINVAL;
++
+ return 0;
+}
+diff --git a/include/linux/of.h b/include/linux/of.h
+index 5d51891cbf1a..3375f5295875 100644
+--- a/include/linux/of.h
++++ b/include/linux/of.h
+@@ -558,6 +558,11 @@ int of_map_id(struct device_node *np, u32 id,
+ const char *map_name, const char *map_mask_name,
+ struct device_node **target, u32 *id_out);
+
++struct kimage;
++int of_kexec_setup_new_fdt(const struct kimage *image, void *fdt,
++ unsigned long initrd_load_addr, unsigned long initrd_len,
++ const char *cmdline);
++
+ #else /* CONFIG_OF */
+
+ static inline void of_core_init(void)
--
-2.28.0
-
+2.30.0
+