[PATCH v17 00/10] Carry forward IMA measurement log on kexec on ARM64

[PATCH v17 00/10] Carry forward IMA measurement log on kexec on ARM64

[Lakshmi Ramasubramanian]

On kexec file load Integrity Measurement Architecture (IMA) subsystem
may verify the IMA signature of the kernel and initramfs, and measure
it.  The command line parameters passed to the kernel in the kexec call
may also be measured by IMA.  A remote attestation service can verify
a TPM quote based on the TPM event log, the IMA measurement list, and
the TPM PCR data.  This can be achieved only if the IMA measurement log
is carried over from the current kernel to the next kernel across
the kexec call.

powerpc already supports carrying forward the IMA measurement log on
kexec.  This patch set adds support for carrying forward the IMA
measurement log on kexec on ARM64.

This patch set moves the platform independent code defined for powerpc
such that it can be reused for other platforms as well.  A chosen node
"linux,ima-kexec-buffer" is added to the DTB for ARM64 to hold
the address and the size of the memory reserved to carry
the IMA measurement log.

This patch set has been tested for ARM64 platform using QEMU.
I would like help from the community for testing this change on powerpc.
Thanks.

This patch set is based on
commit 96acc833dec8 ("ima: Free IMA measurement buffer after kexec syscall")
in https://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git
"next-integrity" branch.

Changelog:

v17
  - Renamed of_kexec_setup_new_fdt() to of_kexec_alloc_and_setup_fdt(),
    and moved memory allocation for the new FDT to this function.

v16
  - Defined functions to allocate and free buffer for FDT for powerpc
    and arm64.
  - Moved ima_buffer_addr and ima_buffer_size fields from
    "struct kimage_arch" in powerpc to "struct kimage"
v15
  - Included Rob's patches in the patch set, and rebased
    the changes to "next-integrity" branch.
  - Allocate memory for DTB, on arm64, using kmalloc() instead of
    vmalloc() to keep it consistent with powerpc implementation.
  - Call of_kexec_setup_new_fdt() from setup_new_fdt_ppc64() and
    remove setup_new_fdt() in the same patch to keep it bisect safe.

v14
  - Select CONFIG_HAVE_IMA_KEXEC for CONFIG_KEXEC_FILE, for powerpc
    and arm64, if CONFIG_IMA is enabled.
  - Use IS_ENABLED() macro instead of "#ifdef" in remove_ima_buffer(),
    ima_get_kexec_buffer(), and ima_free_kexec_buffer().
  - Call of_kexec_setup_new_fdt() from setup_new_fdt_ppc64() and
    remove setup_new_fdt() in "arch/powerpc/kexec/file_load.c".

v13
  - Moved the arch independent functions to drivers/of/kexec.c
    and then refactored the code.
  - Moved arch_ima_add_kexec_buffer() to
    security/integrity/ima/ima_kexec.c

v12
  - Use fdt_appendprop_addrrange() in setup_ima_buffer()
    to setup the IMA measurement list property in
    the device tree.
  - Moved architecture independent functions from
    "arch/powerpc/kexec/ima.c" to "drivers/of/kexec."
  - Deleted "arch/powerpc/kexec/ima.c" and
    "arch/powerpc/include/asm/ima.h".

v11
  - Rebased the changes on the kexec code refactoring done by
    Rob Herring in his "dt/kexec" branch
  - Removed "extern" keyword in function declarations
  - Removed unnecessary header files included in C files
  - Updated patch descriptions per Thiago's comments

v10
  - Moved delete_fdt_mem_rsv(), remove_ima_buffer(),
    get_ima_kexec_buffer, and get_root_addr_size_cells()
    to drivers/of/kexec.c
  - Moved arch_ima_add_kexec_buffer() to
    security/integrity/ima/ima_kexec.c
  - Conditionally define IMA buffer fields in struct kimage_arch

v9
  - Moved delete_fdt_mem_rsv() to drivers/of/kexec_fdt.c
  - Defined a new function get_ima_kexec_buffer() in
    drivers/of/ima_kexec.c to replace do_get_kexec_buffer()
  - Changed remove_ima_kexec_buffer() to the original function name
    remove_ima_buffer()
  - Moved remove_ima_buffer() to drivers/of/ima_kexec.c
  - Moved ima_get_kexec_buffer() and ima_free_kexec_buffer()
    to security/integrity/ima/ima_kexec.c

v8:
  - Moved remove_ima_kexec_buffer(), do_get_kexec_buffer(), and
    delete_fdt_mem_rsv() to drivers/of/fdt.c
  - Moved ima_dump_measurement_list() and ima_add_kexec_buffer()
    back to security/integrity/ima/ima_kexec.c

v7:
  - Renamed remove_ima_buffer() to remove_ima_kexec_buffer() and moved
    this function definition to kernel.
  - Moved delete_fdt_mem_rsv() definition to kernel
  - Moved ima_dump_measurement_list() and ima_add_kexec_buffer() to
    a new file namely ima_kexec_fdt.c in IMA

v6:
  - Remove any existing FDT_PROP_IMA_KEXEC_BUFFER property in the device
    tree and also its corresponding memory reservation in the currently
    running kernel.
  - Moved the function remove_ima_buffer() defined for powerpc to IMA
    and renamed the function to ima_remove_kexec_buffer(). Also, moved
    delete_fdt_mem_rsv() from powerpc to IMA.

v5:
  - Merged get_addr_size_cells() and do_get_kexec_buffer() into a single
    function when moving the arch independent code from powerpc to IMA
  - Reverted the change to use FDT functions in powerpc code and added
    back the original code in get_addr_size_cells() and
    do_get_kexec_buffer() for powerpc.
  - Added fdt_add_mem_rsv() for ARM64 to reserve the memory for
    the IMA log buffer during kexec.
  - Fixed the warning reported by kernel test bot for ARM64
    arch_ima_add_kexec_buffer() - moved this function to a new file
    namely arch/arm64/kernel/ima_kexec.c

v4:
  - Submitting the patch series on behalf of the original author
    Prakhar Srivastava <prsriva@linux.microsoft.com>
  - Moved FDT_PROP_IMA_KEXEC_BUFFER ("linux,ima-kexec-buffer") to
    libfdt.h so that it can be shared by multiple platforms.

v3:
Breakup patches further into separate patches.
  - Refactoring non architecture specific code out of powerpc
  - Update powerpc related code to use fdt functions
  - Update IMA buffer read related code to use of functions
  - Add support to store the memory information of the IMA
    measurement logs to be carried forward.
  - Update the property strings to align with documented nodes
    https://github.com/devicetree-org/dt-schema/pull/46

v2:
  Break patches into separate patches.
  - Powerpc related Refactoring
  - Updating the docuemntation for chosen node
  - Updating arm64 to support IMA buffer pass

v1:
  Refactoring carrying over IMA measuremnet logs over Kexec. This patch
    moves the non-architecture specific code out of powerpc and adds to
    security/ima.(Suggested by Thiago)
  Add Documentation regarding the ima-kexec-buffer node in the chosen
    node documentation

v0:
  Add a layer of abstraction to use the memory reserved by device tree
    for ima buffer pass.
  Add support for ima buffer pass using reserved memory for arm64 kexec.
    Update the arch sepcific code path in kexec file load to store the
    ima buffer in the reserved memory. The same reserved memory is read
    on kexec or cold boot.

Lakshmi Ramasubramanian (6):
  powerpc: Move ima buffer fields to struct kimage
  powerpc: Enable passing IMA log to next kernel on kexec
  powerpc: Move arch independent ima kexec functions to
    drivers/of/kexec.c
  kexec: Use fdt_appendprop_addrrange() to add ima buffer to FDT
  powerpc: Delete unused function delete_fdt_mem_rsv()
  arm64: Enable passing IMA log to next kernel on kexec

Rob Herring (4):
  powerpc: Rename kexec elfcorehdr_addr to elf_headers_mem
  of: Add a common kexec FDT setup function
  arm64: Use common of_kexec_alloc_and_setup_fdt()
  powerpc: Use common of_kexec_alloc_and_setup_fdt()

 arch/arm64/Kconfig                     |   1 +
 arch/arm64/kernel/machine_kexec_file.c | 180 +---------
 arch/powerpc/Kconfig                   |   2 +-
 arch/powerpc/include/asm/ima.h         |  30 --
 arch/powerpc/include/asm/kexec.h       |  12 +-
 arch/powerpc/kexec/Makefile            |   7 -
 arch/powerpc/kexec/elf_64.c            |  29 +-
 arch/powerpc/kexec/file_load.c         | 183 +---------
 arch/powerpc/kexec/file_load_64.c      |  11 +-
 arch/powerpc/kexec/ima.c               | 219 ------------
 drivers/of/Makefile                    |   6 +
 drivers/of/kexec.c                     | 473 +++++++++++++++++++++++++
 include/linux/kexec.h                  |   3 +
 include/linux/of.h                     |  20 ++
 security/integrity/ima/ima.h           |   4 -
 security/integrity/ima/ima_kexec.c     |   3 +-
 16 files changed, 539 insertions(+), 644 deletions(-)
 delete mode 100644 arch/powerpc/include/asm/ima.h
 delete mode 100644 arch/powerpc/kexec/ima.c
 create mode 100644 drivers/of/kexec.c

-- 
2.30.0

[PATCH v17 01/10] powerpc: Rename kexec elfcorehdr_addr to elf_headers_mem

[Lakshmi Ramasubramanian]

From: Rob Herring <robh@kernel.org>

The architecture specific field, elfcorehdr_addr in struct kimage_arch,
that holds the address of the buffer in memory for ELF core header for
powerpc has a different name than the one used for arm64.  This makes
it hard to have a common code for setting up the device tree for
kexec system call.

Rename elfcorehdr_addr to elf_headers_mem to align with arm64 name so
common code can use it.

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/powerpc/include/asm/kexec.h  | 2 +-
 arch/powerpc/kexec/file_load.c    | 4 ++--
 arch/powerpc/kexec/file_load_64.c | 4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index 55d6ede30c19..dbf09d2f36d0 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -108,7 +108,7 @@ struct kimage_arch {
 	unsigned long backup_start;
 	void *backup_buf;
 
-	unsigned long elfcorehdr_addr;
+	unsigned long elf_headers_mem;
 	unsigned long elf_headers_sz;
 	void *elf_headers;
 
diff --git a/arch/powerpc/kexec/file_load.c b/arch/powerpc/kexec/file_load.c
index 9a232bc36c8f..e452b11df631 100644
--- a/arch/powerpc/kexec/file_load.c
+++ b/arch/powerpc/kexec/file_load.c
@@ -45,7 +45,7 @@ char *setup_kdump_cmdline(struct kimage *image, char *cmdline,
 		return NULL;
 
 	elfcorehdr_strlen = sprintf(cmdline_ptr, "elfcorehdr=0x%lx ",
-				    image->arch.elfcorehdr_addr);
+				    image->arch.elf_headers_mem);
 
 	if (elfcorehdr_strlen + cmdline_len > COMMAND_LINE_SIZE) {
 		pr_err("Appending elfcorehdr=<addr> exceeds cmdline size\n");
@@ -263,7 +263,7 @@ int setup_new_fdt(const struct kimage *image, void *fdt,
 		 * Avoid elfcorehdr from being stomped on in kdump kernel by
 		 * setting up memory reserve map.
 		 */
-		ret = fdt_add_mem_rsv(fdt, image->arch.elfcorehdr_addr,
+		ret = fdt_add_mem_rsv(fdt, image->arch.elf_headers_mem,
 				      image->arch.elf_headers_sz);
 		if (ret) {
 			pr_err("Error reserving elfcorehdr memory: %s\n",
diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c
index c69bcf9b547a..a05c19b3cc60 100644
--- a/arch/powerpc/kexec/file_load_64.c
+++ b/arch/powerpc/kexec/file_load_64.c
@@ -815,7 +815,7 @@ static int load_elfcorehdr_segment(struct kimage *image, struct kexec_buf *kbuf)
 		goto out;
 	}
 
-	image->arch.elfcorehdr_addr = kbuf->mem;
+	image->arch.elf_headers_mem = kbuf->mem;
 	image->arch.elf_headers_sz = headers_sz;
 	image->arch.elf_headers = headers;
 out:
@@ -851,7 +851,7 @@ int load_crashdump_segments_ppc64(struct kimage *image,
 		return ret;
 	}
 	pr_debug("Loaded elf core header at 0x%lx, bufsz=0x%lx memsz=0x%lx\n",
-		 image->arch.elfcorehdr_addr, kbuf->bufsz, kbuf->memsz);
+		 image->arch.elf_headers_mem, kbuf->bufsz, kbuf->memsz);
 
 	return 0;
 }
-- 
2.30.0

[PATCH v17 02/10] of: Add a common kexec FDT setup function

[Lakshmi Ramasubramanian]

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_alloc_and_setup_fdt() and move it to "drivers/of/kexec.c".

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
---
 drivers/of/Makefile |   6 ++
 drivers/of/kexec.c  | 258 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/of.h  |  13 +++
 3 files changed, 277 insertions(+)
 create mode 100644 drivers/of/kexec.c

diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index 6e1e5212f058..c13b982084a3 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -14,4 +14,10 @@ obj-$(CONFIG_OF_RESOLVE)  += resolver.o
 obj-$(CONFIG_OF_OVERLAY) += overlay.o
 obj-$(CONFIG_OF_NUMA) += of_numa.o
 
+ifdef CONFIG_KEXEC_FILE
+ifdef CONFIG_OF_FLATTREE
+obj-y	+= kexec.o
+endif
+endif
+
 obj-$(CONFIG_OF_UNITTEST) += unittest-data/
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
new file mode 100644
index 000000000000..469e09613cdd
--- /dev/null
+++ b/drivers/of/kexec.c
@@ -0,0 +1,258 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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>
+
+/* 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
+
+/**
+ * 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.
+ */
+static int fdt_find_and_del_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++) {
+		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_alloc_and_setup_fdt - Alloc and setup a new Flattened Device Tree
+ *
+ * @image:		kexec image being loaded.
+ * @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: fdt on success, or NULL errno on error.
+ */
+void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
+				   unsigned long initrd_load_addr,
+				   unsigned long initrd_len,
+				   const char *cmdline)
+{
+	void *fdt;
+	int ret, chosen_node;
+	const void *prop;
+	unsigned long fdt_size;
+
+	fdt_size = fdt_totalsize(initial_boot_params) +
+		   (cmdline ? strlen(cmdline) : 0) +
+		   FDT_EXTRA_SPACE;
+
+	fdt = kvmalloc(fdt_size, GFP_KERNEL);
+	if (!fdt)
+		return NULL;
+
+	ret = fdt_open_into(initial_boot_params, fdt, fdt_size);
+	if (ret < 0) {
+		pr_err("Error %d setting up the new device tree.\n", ret);
+		goto out;
+	}
+
+	/* 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) {
+		pr_err("Error removing memory reservation.\n");
+		goto out;
+	}
+
+	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) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		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)
+			goto out;
+	}
+
+	/* 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) {
+		kvfree(fdt);
+		fdt = NULL;
+	}
+
+	return fdt;
+}
diff --git a/include/linux/of.h b/include/linux/of.h
index 4b27c9a27df3..f0eff5e84353 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -560,6 +560,19 @@ int of_map_id(struct device_node *np, u32 id,
 
 phys_addr_t of_dma_get_max_cpu_address(struct device_node *np);
 
+/*
+ * Additional space needed for the buffer to build the new FDT
+ * so that we can add initrd, bootargs, kaslr-seed, rng-seed,
+ * userable-memory-range and elfcorehdr.
+ */
+#define FDT_EXTRA_SPACE 0x1000
+
+struct kimage;
+void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
+				   unsigned long initrd_load_addr,
+				   unsigned long initrd_len,
+				   const char *cmdline);
+
 #else /* CONFIG_OF */
 
 static inline void of_core_init(void)
-- 
2.30.0

[PATCH v17 03/10] arm64: Use common of_kexec_alloc_and_setup_fdt()

[Lakshmi Ramasubramanian]

From: Rob Herring <robh@kernel.org>

The code for setting up the /chosen node in the device tree
and updating the memory reservation for the next kernel has been
moved to of_kexec_alloc_and_setup_fdt() defined in "drivers/of/kexec.c".

Use the common of_kexec_alloc_and_setup_fdt() to setup the device tree
and update the memory reservation for kexec for arm64.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
---
 arch/arm64/kernel/machine_kexec_file.c | 180 ++-----------------------
 1 file changed, 8 insertions(+), 172 deletions(-)

diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
index 03210f644790..5a203f4f31fd 100644
--- a/arch/arm64/kernel/machine_kexec_file.c
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -15,23 +15,12 @@
 #include <linux/kexec.h>
 #include <linux/libfdt.h>
 #include <linux/memblock.h>
+#include <linux/of.h>
 #include <linux/of_fdt.h>
-#include <linux/random.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/types.h>
 #include <linux/vmalloc.h>
-#include <asm/byteorder.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
 
 const struct kexec_file_ops * const kexec_file_loaders[] = {
 	&kexec_image_ops,
@@ -40,7 +29,7 @@ const struct kexec_file_ops * const kexec_file_loaders[] = {
 
 int arch_kimage_file_post_load_cleanup(struct kimage *image)
 {
-	vfree(image->arch.dtb);
+	kvfree(image->arch.dtb);
 	image->arch.dtb = NULL;
 
 	vfree(image->arch.elf_headers);
@@ -50,162 +39,6 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image)
 	return kexec_image_post_load_cleanup_default(image);
 }
 
-static int setup_dtb(struct kimage *image,
-		     unsigned long initrd_load_addr, unsigned long initrd_len,
-		     char *cmdline, void *dtb)
-{
-	int off, ret;
-
-	ret = fdt_path_offset(dtb, "/chosen");
-	if (ret < 0)
-		goto out;
-
-	off = ret;
-
-	ret = fdt_delprop(dtb, off, FDT_PROP_KEXEC_ELFHDR);
-	if (ret && ret != -FDT_ERR_NOTFOUND)
-		goto out;
-	ret = fdt_delprop(dtb, off, FDT_PROP_MEM_RANGE);
-	if (ret && ret != -FDT_ERR_NOTFOUND)
-		goto out;
-
-	if (image->type == KEXEC_TYPE_CRASH) {
-		/* add linux,elfcorehdr */
-		ret = fdt_appendprop_addrrange(dtb, 0, off,
-				FDT_PROP_KEXEC_ELFHDR,
-				image->arch.elf_headers_mem,
-				image->arch.elf_headers_sz);
-		if (ret)
-			return (ret == -FDT_ERR_NOSPACE ? -ENOMEM : -EINVAL);
-
-		/* add linux,usable-memory-range */
-		ret = fdt_appendprop_addrrange(dtb, 0, off,
-				FDT_PROP_MEM_RANGE,
-				crashk_res.start,
-				crashk_res.end - crashk_res.start + 1);
-		if (ret)
-			return (ret == -FDT_ERR_NOSPACE ? -ENOMEM : -EINVAL);
-	}
-
-	/* add bootargs */
-	if (cmdline) {
-		ret = fdt_setprop_string(dtb, off, FDT_PROP_BOOTARGS, cmdline);
-		if (ret)
-			goto out;
-	} else {
-		ret = fdt_delprop(dtb, off, FDT_PROP_BOOTARGS);
-		if (ret && (ret != -FDT_ERR_NOTFOUND))
-			goto out;
-	}
-
-	/* add initrd-* */
-	if (initrd_load_addr) {
-		ret = fdt_setprop_u64(dtb, off, FDT_PROP_INITRD_START,
-				      initrd_load_addr);
-		if (ret)
-			goto out;
-
-		ret = fdt_setprop_u64(dtb, off, FDT_PROP_INITRD_END,
-				      initrd_load_addr + initrd_len);
-		if (ret)
-			goto out;
-	} else {
-		ret = fdt_delprop(dtb, off, FDT_PROP_INITRD_START);
-		if (ret && (ret != -FDT_ERR_NOTFOUND))
-			goto out;
-
-		ret = fdt_delprop(dtb, off, FDT_PROP_INITRD_END);
-		if (ret && (ret != -FDT_ERR_NOTFOUND))
-			goto out;
-	}
-
-	/* add kaslr-seed */
-	ret = fdt_delprop(dtb, off, 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(dtb, off, 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(dtb, off, 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);
-	}
-
-out:
-	if (ret)
-		return (ret == -FDT_ERR_NOSPACE) ? -ENOMEM : -EINVAL;
-
-	return 0;
-}
-
-/*
- * More space needed so that we can add initrd, bootargs, kaslr-seed,
- * rng-seed, userable-memory-range and elfcorehdr.
- */
-#define DTB_EXTRA_SPACE 0x1000
-
-static int create_dtb(struct kimage *image,
-		      unsigned long initrd_load_addr, unsigned long initrd_len,
-		      char *cmdline, void **dtb)
-{
-	void *buf;
-	size_t buf_size;
-	size_t cmdline_len;
-	int ret;
-
-	cmdline_len = cmdline ? strlen(cmdline) : 0;
-	buf_size = fdt_totalsize(initial_boot_params)
-			+ cmdline_len + DTB_EXTRA_SPACE;
-
-	for (;;) {
-		buf = vmalloc(buf_size);
-		if (!buf)
-			return -ENOMEM;
-
-		/* duplicate a device tree blob */
-		ret = fdt_open_into(initial_boot_params, buf, buf_size);
-		if (ret)
-			return -EINVAL;
-
-		ret = setup_dtb(image, initrd_load_addr, initrd_len,
-				cmdline, buf);
-		if (ret) {
-			vfree(buf);
-			if (ret == -ENOMEM) {
-				/* unlikely, but just in case */
-				buf_size += DTB_EXTRA_SPACE;
-				continue;
-			} else {
-				return ret;
-			}
-		}
-
-		/* trim it */
-		fdt_pack(buf);
-		*dtb = buf;
-
-		return 0;
-	}
-}
-
 static int prepare_elf_headers(void **addr, unsigned long *sz)
 {
 	struct crash_mem *cmem;
@@ -312,12 +145,15 @@ int load_other_segments(struct kimage *image,
 	}
 
 	/* load dtb */
-	ret = create_dtb(image, initrd_load_addr, initrd_len, cmdline, &dtb);
-	if (ret) {
+	dtb = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
+					   initrd_len, cmdline);
+	if (!dtb) {
 		pr_err("Preparing for new dtb failed\n");
 		goto out_err;
 	}
 
+	/* trim it */
+	fdt_pack(dtb);
 	dtb_len = fdt_totalsize(dtb);
 	kbuf.buffer = dtb;
 	kbuf.bufsz = dtb_len;
@@ -341,6 +177,6 @@ int load_other_segments(struct kimage *image,
 
 out_err:
 	image->nr_segments = orig_segments;
-	vfree(dtb);
+	kvfree(dtb);
 	return ret;
 }
-- 
2.30.0

[PATCH v17 04/10] powerpc: Use common of_kexec_alloc_and_setup_fdt()

[Lakshmi Ramasubramanian]

From: Rob Herring <robh@kernel.org>

The code for setting up the /chosen node in the device tree
and updating the memory reservation for the next kernel has been
moved to of_kexec_alloc_and_setup_fdt() defined in "drivers/of/kexec.c".

Use the common of_kexec_alloc_and_setup_fdt() to setup the device tree
and update the memory reservation for kexec for powerpc.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
---
 arch/powerpc/include/asm/kexec.h  |   1 +
 arch/powerpc/kexec/elf_64.c       |  29 ++++---
 arch/powerpc/kexec/file_load.c    | 132 +-----------------------------
 arch/powerpc/kexec/file_load_64.c |   3 +
 4 files changed, 25 insertions(+), 140 deletions(-)

diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index dbf09d2f36d0..bdd0ddb9ac4d 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -111,6 +111,7 @@ struct kimage_arch {
 	unsigned long elf_headers_mem;
 	unsigned long elf_headers_sz;
 	void *elf_headers;
+	void *fdt;
 
 #ifdef CONFIG_IMA_KEXEC
 	phys_addr_t ima_buffer_addr;
diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c
index d0e459bb2f05..bfabd06f99b1 100644
--- a/arch/powerpc/kexec/elf_64.c
+++ b/arch/powerpc/kexec/elf_64.c
@@ -19,6 +19,7 @@
 #include <linux/kexec.h>
 #include <linux/libfdt.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/of_fdt.h>
 #include <linux/slab.h>
 #include <linux/types.h>
@@ -29,7 +30,6 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
 			unsigned long cmdline_len)
 {
 	int ret;
-	unsigned int fdt_size;
 	unsigned long kernel_load_addr;
 	unsigned long initrd_load_addr = 0, fdt_load_addr;
 	void *fdt;
@@ -102,19 +102,13 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
 		pr_debug("Loaded initrd at 0x%lx\n", initrd_load_addr);
 	}
 
-	fdt_size = fdt_totalsize(initial_boot_params) * 2;
-	fdt = kmalloc(fdt_size, GFP_KERNEL);
+	fdt = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
+					   initrd_len, cmdline);
 	if (!fdt) {
 		pr_err("Not enough memory for the device tree.\n");
 		ret = -ENOMEM;
 		goto out;
 	}
-	ret = fdt_open_into(initial_boot_params, fdt, fdt_size);
-	if (ret < 0) {
-		pr_err("Error setting up the new device tree.\n");
-		ret = -EINVAL;
-		goto out;
-	}
 
 	ret = setup_new_fdt_ppc64(image, fdt, initrd_load_addr,
 				  initrd_len, cmdline);
@@ -124,13 +118,17 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
 	fdt_pack(fdt);
 
 	kbuf.buffer = fdt;
-	kbuf.bufsz = kbuf.memsz = fdt_size;
+	kbuf.bufsz = kbuf.memsz = fdt_totalsize(fdt);
 	kbuf.buf_align = PAGE_SIZE;
 	kbuf.top_down = true;
 	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
 	ret = kexec_add_buffer(&kbuf);
 	if (ret)
 		goto out;
+
+	/* FDT will be freed in arch_kimage_file_post_load_cleanup */
+	image->arch.fdt = fdt;
+
 	fdt_load_addr = kbuf.mem;
 
 	pr_debug("Loaded device tree at 0x%lx\n", fdt_load_addr);
@@ -145,8 +143,15 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
 	kfree(modified_cmdline);
 	kexec_free_elf_info(&elf_info);
 
-	/* Make kimage_file_post_load_cleanup free the fdt buffer for us. */
-	return ret ? ERR_PTR(ret) : fdt;
+	/*
+	 * Once FDT buffer has been successfully passed to kexec_add_buffer(),
+	 * the FDT buffer address is saved in image->arch.fdt. In that case,
+	 * the memory cannot be freed here in case of any other error.
+	 */
+	if (ret && !image->arch.fdt)
+		kvfree(fdt);
+
+	return ret ? ERR_PTR(ret) : NULL;
 }
 
 const struct kexec_file_ops kexec_elf64_ops = {
diff --git a/arch/powerpc/kexec/file_load.c b/arch/powerpc/kexec/file_load.c
index e452b11df631..d23e2969395c 100644
--- a/arch/powerpc/kexec/file_load.c
+++ b/arch/powerpc/kexec/file_load.c
@@ -156,135 +156,11 @@ 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;
-
-	/* Remove memory reservation for the current device tree. */
-	ret = delete_fdt_mem_rsv(fdt, __pa(initial_boot_params),
-				 fdt_totalsize(initial_boot_params));
-	if (ret == 0)
-		pr_debug("Removed old device tree reservation.\n");
-	else if (ret != -ENOENT)
-		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) {
-			pr_err("Error creating /chosen.\n");
-			return -EINVAL;
-		}
-	} else if (chosen_node < 0) {
-		pr_err("Malformed device tree: error reading /chosen.\n");
-		return -EINVAL;
-	}
-
-	/* Did we boot using an initrd? */
-	prop = fdt_getprop(fdt, chosen_node, "linux,initrd-start", NULL);
-	if (prop) {
-		uint64_t 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) {
-			pr_err("Malformed device tree.\n");
-			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 = delete_fdt_mem_rsv(fdt, tmp_start, tmp_size);
-		if (ret == -ENOENT)
-			ret = delete_fdt_mem_rsv(fdt, tmp_start,
-						 round_up(tmp_size, PAGE_SIZE));
-		if (ret == 0)
-			pr_debug("Removed old initrd reservation.\n");
-		else if (ret != -ENOENT)
-			return ret;
-
-		/* If there's no new initrd, delete the old initrd's info. */
-		if (initrd_len == 0) {
-			ret = fdt_delprop(fdt, chosen_node,
-					  "linux,initrd-start");
-			if (ret) {
-				pr_err("Error deleting linux,initrd-start.\n");
-				return -EINVAL;
-			}
-
-			ret = fdt_delprop(fdt, chosen_node, "linux,initrd-end");
-			if (ret) {
-				pr_err("Error deleting linux,initrd-end.\n");
-				return -EINVAL;
-			}
-		}
-	}
-
-	if (initrd_len) {
-		ret = fdt_setprop_u64(fdt, chosen_node,
-				      "linux,initrd-start",
-				      initrd_load_addr);
-		if (ret < 0)
-			goto err;
-
-		/* initrd-end is the first address after the initrd image. */
-		ret = fdt_setprop_u64(fdt, chosen_node, "linux,initrd-end",
-				      initrd_load_addr + initrd_len);
-		if (ret < 0)
-			goto err;
-
-		ret = fdt_add_mem_rsv(fdt, initrd_load_addr, initrd_len);
-		if (ret) {
-			pr_err("Error reserving initrd memory: %s\n",
-			       fdt_strerror(ret));
-			return -EINVAL;
-		}
-	}
-
-	if (cmdline != NULL) {
-		ret = fdt_setprop_string(fdt, chosen_node, "bootargs", cmdline);
-		if (ret < 0)
-			goto err;
-	} else {
-		ret = fdt_delprop(fdt, chosen_node, "bootargs");
-		if (ret && ret != -FDT_ERR_NOTFOUND) {
-			pr_err("Error deleting bootargs.\n");
-			return -EINVAL;
-		}
-	}
-
-	if (image->type == KEXEC_TYPE_CRASH) {
-		/*
-		 * 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) {
-			pr_err("Error reserving elfcorehdr memory: %s\n",
-			       fdt_strerror(ret));
-			goto err;
-		}
-	}
-
-	ret = setup_ima_buffer(image, fdt, chosen_node);
-	if (ret) {
-		pr_err("Error setting up the new device tree.\n");
-		return ret;
-	}
+	int ret;
 
-	ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0);
+	ret = setup_ima_buffer(image, fdt, fdt_path_offset(fdt, "/chosen"));
 	if (ret)
-		goto err;
-
-	return 0;
+		pr_err("Error setting up the new device tree.\n");
 
-err:
-	pr_err("Error setting up the new device tree.\n");
-	return -EINVAL;
+	return ret;
 }
diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c
index a05c19b3cc60..dac3d29c7c77 100644
--- a/arch/powerpc/kexec/file_load_64.c
+++ b/arch/powerpc/kexec/file_load_64.c
@@ -1111,5 +1111,8 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image)
 	image->arch.elf_headers = NULL;
 	image->arch.elf_headers_sz = 0;
 
+	kvfree(image->arch.fdt);
+	image->arch.fdt = NULL;
+
 	return kexec_image_post_load_cleanup_default(image);
 }
-- 
2.30.0

[PATCH v17 05/10] powerpc: Move ima buffer fields to struct kimage

[Lakshmi Ramasubramanian]

The fields ima_buffer_addr and ima_buffer_size in "struct kimage_arch"
for powerpc are used to carry forward the IMA measurement list across
kexec system call.  These fields are not architecture specific, but are
currently limited to powerpc.

arch_ima_add_kexec_buffer() defined in "arch/powerpc/kexec/ima.c"
sets ima_buffer_addr and ima_buffer_size for the kexec system call.
This function does not have architecture specific code, but is
currently limited to powerpc.

Move ima_buffer_addr and ima_buffer_size to "struct kimage".
Rename arch_ima_add_kexec_buffer() to of_ima_add_kexec_buffer()
and move it in drivers/of/kexec.c.

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>
Suggested-by: Will Deacon <will@kernel.org>
---
 arch/powerpc/include/asm/ima.h     |  3 ---
 arch/powerpc/include/asm/kexec.h   |  5 -----
 arch/powerpc/kexec/ima.c           | 29 ++++++-----------------------
 drivers/of/kexec.c                 | 23 +++++++++++++++++++++++
 include/linux/kexec.h              |  3 +++
 include/linux/of.h                 |  5 +++++
 security/integrity/ima/ima_kexec.c |  3 ++-
 7 files changed, 39 insertions(+), 32 deletions(-)

diff --git a/arch/powerpc/include/asm/ima.h b/arch/powerpc/include/asm/ima.h
index ead488cf3981..51f64fd06c19 100644
--- a/arch/powerpc/include/asm/ima.h
+++ b/arch/powerpc/include/asm/ima.h
@@ -14,9 +14,6 @@ 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,
diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index bdd0ddb9ac4d..ecf88533d6b4 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -112,11 +112,6 @@ struct kimage_arch {
 	unsigned long elf_headers_sz;
 	void *elf_headers;
 	void *fdt;
-
-#ifdef CONFIG_IMA_KEXEC
-	phys_addr_t ima_buffer_addr;
-	size_t ima_buffer_size;
-#endif
 };
 
 char *setup_kdump_cmdline(struct kimage *image, char *cmdline,
diff --git a/arch/powerpc/kexec/ima.c b/arch/powerpc/kexec/ima.c
index 720e50e490b6..ed38125e2f87 100644
--- a/arch/powerpc/kexec/ima.c
+++ b/arch/powerpc/kexec/ima.c
@@ -128,23 +128,6 @@ void remove_ima_buffer(void *fdt, int chosen_node)
 }
 
 #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) {
@@ -180,7 +163,7 @@ int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node)
 	u8 value[16];
 
 	remove_ima_buffer(fdt, chosen_node);
-	if (!image->arch.ima_buffer_size)
+	if (!image->ima_buffer_size)
 		return 0;
 
 	ret = get_addr_size_cells(&addr_cells, &size_cells);
@@ -192,11 +175,11 @@ int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node)
 	if (entry_size > sizeof(value))
 		return -EINVAL;
 
-	ret = write_number(value, image->arch.ima_buffer_addr, addr_cells);
+	ret = write_number(value, image->ima_buffer_addr, addr_cells);
 	if (ret)
 		return ret;
 
-	ret = write_number(value + 4 * addr_cells, image->arch.ima_buffer_size,
+	ret = write_number(value + 4 * addr_cells, image->ima_buffer_size,
 			   size_cells);
 	if (ret)
 		return ret;
@@ -206,13 +189,13 @@ int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node)
 	if (ret < 0)
 		return -EINVAL;
 
-	ret = fdt_add_mem_rsv(fdt, image->arch.ima_buffer_addr,
-			      image->arch.ima_buffer_size);
+	ret = fdt_add_mem_rsv(fdt, image->ima_buffer_addr,
+			      image->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);
+		 image->ima_buffer_addr, image->ima_buffer_size);
 
 	return 0;
 }
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index 469e09613cdd..9f33d215b9f2 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -63,6 +63,29 @@ static int fdt_find_and_del_mem_rsv(void *fdt, unsigned long start, unsigned lon
 	return -ENOENT;
 }
 
+#ifdef CONFIG_IMA_KEXEC
+/**
+ * of_ima_add_kexec_buffer - Add IMA buffer for next kernel
+ *
+ * @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
+ *
+ * Use this function to pass on the IMA buffer information to
+ * the next kernel across kexec system call.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int of_ima_add_kexec_buffer(struct kimage *image,
+			    unsigned long load_addr, size_t size)
+{
+	image->ima_buffer_addr = load_addr;
+	image->ima_buffer_size = size;
+
+	return 0;
+}
+#endif /* CONFIG_IMA_KEXEC */
+
 /*
  * of_kexec_alloc_and_setup_fdt - Alloc and setup a new Flattened Device Tree
  *
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 5f61389f5f36..75c670f0dfbb 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -304,6 +304,9 @@ struct kimage {
 #ifdef CONFIG_IMA_KEXEC
 	/* Virtual address of IMA measurement buffer for kexec syscall */
 	void *ima_buffer;
+
+	phys_addr_t ima_buffer_addr;
+	size_t ima_buffer_size;
 #endif
 };
 
diff --git a/include/linux/of.h b/include/linux/of.h
index f0eff5e84353..03e0e694be29 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -573,6 +573,11 @@ void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
 				   unsigned long initrd_len,
 				   const char *cmdline);
 
+#ifdef CONFIG_IMA_KEXEC
+int of_ima_add_kexec_buffer(struct kimage *image,
+			    unsigned long load_addr, size_t size);
+#endif /* CONFIG_IMA_KEXEC */
+
 #else /* CONFIG_OF */
 
 static inline void of_core_init(void)
diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c
index e29bea3dd4cc..d346eed2d236 100644
--- a/security/integrity/ima/ima_kexec.c
+++ b/security/integrity/ima/ima_kexec.c
@@ -10,6 +10,7 @@
 #include <linux/seq_file.h>
 #include <linux/vmalloc.h>
 #include <linux/kexec.h>
+#include <linux/of.h>
 #include "ima.h"
 
 #ifdef CONFIG_IMA_KEXEC
@@ -123,7 +124,7 @@ void ima_add_kexec_buffer(struct kimage *image)
 		return;
 	}
 
-	ret = arch_ima_add_kexec_buffer(image, kbuf.mem, kexec_segment_size);
+	ret = of_ima_add_kexec_buffer(image, kbuf.mem, kexec_segment_size);
 	if (ret) {
 		pr_err("Error passing over kexec measurement buffer.\n");
 		return;
-- 
2.30.0

[PATCH v17 06/10] powerpc: Enable passing IMA log to next kernel on kexec

[Lakshmi Ramasubramanian]

CONFIG_HAVE_IMA_KEXEC is enabled to indicate that the IMA measurement
log information is present in the device tree. This should be selected
only if CONFIG_IMA is enabled.

Update CONFIG_KEXEC_FILE to select CONFIG_HAVE_IMA_KEXEC, if CONFIG_IMA
is enabled, to indicate that the IMA measurement log information is
present in the device tree for powerpc.

Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Suggested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
---
 arch/powerpc/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 107bb4319e0e..d6e593ad270e 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -554,7 +554,7 @@ config KEXEC
 config KEXEC_FILE
 	bool "kexec file based system call"
 	select KEXEC_CORE
-	select HAVE_IMA_KEXEC
+	select HAVE_IMA_KEXEC if IMA
 	select BUILD_BIN2C
 	select KEXEC_ELF
 	depends on PPC64
-- 
2.30.0

[PATCH v17 07/10] powerpc: Move arch independent ima kexec functions to drivers/of/kexec.c

[Lakshmi Ramasubramanian]

The functions defined in "arch/powerpc/kexec/ima.c" handle setting up
and freeing the resources required to carry over the IMA measurement
list from the current kernel to the next kernel across kexec system call.
These functions do not have architecture specific code, but are
currently limited to powerpc.

Move remove_ima_buffer() and setup_ima_buffer() calls into
of_kexec_alloc_and_setup_fdt() defined in "drivers/of/kexec.c".

Move the remaining architecture independent functions from
"arch/powerpc/kexec/ima.c" to "drivers/of/kexec.c".
Delete "arch/powerpc/kexec/ima.c" and "arch/powerpc/include/asm/ima.h".
Remove references to the deleted files and functions in powerpc and
in ima.

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>
---
 arch/powerpc/include/asm/ima.h    |  27 ----
 arch/powerpc/include/asm/kexec.h  |   3 -
 arch/powerpc/kexec/Makefile       |   7 -
 arch/powerpc/kexec/file_load.c    |  25 ----
 arch/powerpc/kexec/file_load_64.c |   4 -
 arch/powerpc/kexec/ima.c          | 202 -------------------------
 drivers/of/kexec.c                | 239 ++++++++++++++++++++++++++++++
 include/linux/of.h                |   2 +
 security/integrity/ima/ima.h      |   4 -
 9 files changed, 241 insertions(+), 272 deletions(-)
 delete mode 100644 arch/powerpc/include/asm/ima.h
 delete mode 100644 arch/powerpc/kexec/ima.c

diff --git a/arch/powerpc/include/asm/ima.h b/arch/powerpc/include/asm/ima.h
deleted file mode 100644
index 51f64fd06c19..000000000000
--- a/arch/powerpc/include/asm/ima.h
+++ /dev/null
@@ -1,27 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#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);
-
-#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 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 ecf88533d6b4..2b87993f6e66 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -119,9 +119,6 @@ char *setup_kdump_cmdline(struct kimage *image, char *cmdline,
 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(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
diff --git a/arch/powerpc/kexec/Makefile b/arch/powerpc/kexec/Makefile
index 4aff6846c772..b6c52608cb49 100644
--- a/arch/powerpc/kexec/Makefile
+++ b/arch/powerpc/kexec/Makefile
@@ -9,13 +9,6 @@ obj-$(CONFIG_PPC32)		+= relocate_32.o
 
 obj-$(CONFIG_KEXEC_FILE)	+= file_load.o ranges.o file_load_$(BITS).o elf_$(BITS).o
 
-ifdef CONFIG_HAVE_IMA_KEXEC
-ifdef CONFIG_IMA
-obj-y				+= ima.o
-endif
-endif
-
-
 # Disable GCOV, KCOV & sanitizers in odd or sensitive code
 GCOV_PROFILE_core_$(BITS).o := n
 KCOV_INSTRUMENT_core_$(BITS).o := n
diff --git a/arch/powerpc/kexec/file_load.c b/arch/powerpc/kexec/file_load.c
index d23e2969395c..bd8b956aafc3 100644
--- a/arch/powerpc/kexec/file_load.c
+++ b/arch/powerpc/kexec/file_load.c
@@ -19,7 +19,6 @@
 #include <linux/of_fdt.h>
 #include <linux/libfdt.h>
 #include <asm/setup.h>
-#include <asm/ima.h>
 
 #define SLAVE_CODE_SIZE		256	/* First 0x100 bytes */
 
@@ -140,27 +139,3 @@ int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size)
 
 	return -ENOENT;
 }
-
-/*
- * 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 setup_new_fdt(const struct kimage *image, void *fdt,
-		  unsigned long initrd_load_addr, unsigned long initrd_len,
-		  const char *cmdline)
-{
-	int ret;
-
-	ret = setup_ima_buffer(image, fdt, fdt_path_offset(fdt, "/chosen"));
-	if (ret)
-		pr_err("Error setting up the new device tree.\n");
-
-	return ret;
-}
diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c
index dac3d29c7c77..a2b0579f7661 100644
--- a/arch/powerpc/kexec/file_load_64.c
+++ b/arch/powerpc/kexec/file_load_64.c
@@ -944,10 +944,6 @@ int setup_new_fdt_ppc64(const struct kimage *image, void *fdt,
 	struct crash_mem *umem = NULL, *rmem = NULL;
 	int i, nr_ranges, ret;
 
-	ret = setup_new_fdt(image, fdt, initrd_load_addr, initrd_len, cmdline);
-	if (ret)
-		goto out;
-
 	/*
 	 * Restrict memory usage for kdump kernel by setting up
 	 * usable memory ranges and memory reserve map.
diff --git a/arch/powerpc/kexec/ima.c b/arch/powerpc/kexec/ima.c
deleted file mode 100644
index ed38125e2f87..000000000000
--- a/arch/powerpc/kexec/ima.c
+++ /dev/null
@@ -1,202 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * Copyright (C) 2016 IBM Corporation
- *
- * Authors:
- * Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
- */
-
-#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
-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->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->ima_buffer_addr, addr_cells);
-	if (ret)
-		return ret;
-
-	ret = write_number(value + 4 * addr_cells, image->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->ima_buffer_addr,
-			      image->ima_buffer_size);
-	if (ret)
-		return -EINVAL;
-
-	pr_debug("IMA buffer at 0x%llx, size = 0x%zx\n",
-		 image->ima_buffer_addr, image->ima_buffer_size);
-
-	return 0;
-}
-#endif /* CONFIG_IMA_KEXEC */
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index 9f33d215b9f2..c601b5af4a88 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -11,6 +11,7 @@
 
 #include <linux/kernel.h>
 #include <linux/kexec.h>
+#include <linux/memblock.h>
 #include <linux/libfdt.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
@@ -63,6 +64,152 @@ static int fdt_find_and_del_mem_rsv(void *fdt, unsigned long start, unsigned lon
 	return -ENOENT;
 }
 
+
+/**
+ * get_addr_size_cells - Get address and size of root node
+ *
+ * @addr_cells: Return address of the root node
+ * @size_cells: Return size of the root node
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+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;
+}
+
+/**
+ * do_get_kexec_buffer - Get address and size of device tree property
+ *
+ * @prop: Device tree property
+ * @len: Size of @prop
+ * @addr: Return address of the node
+ * @size: Return size of the node
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+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;
+}
+
+/**
+ * remove_ima_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.
+ */
+static void remove_ima_buffer(void *fdt, int chosen_node)
+{
+	int ret, len;
+	unsigned long addr;
+	size_t size;
+	const void *prop;
+
+	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
+		return;
+
+	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 = fdt_find_and_del_mem_rsv(fdt, addr, size);
+	if (!ret)
+		pr_debug("Removed old IMA buffer reservation.\n");
+}
+
+/**
+ * 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;
+
+	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
+		return -ENOTSUPP;
+
+	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;
+
+	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
+		return -ENOTSUPP;
+
+	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);
+
+}
+
 #ifdef CONFIG_IMA_KEXEC
 /**
  * of_ima_add_kexec_buffer - Add IMA buffer for next kernel
@@ -84,6 +231,93 @@ int of_ima_add_kexec_buffer(struct kimage *image,
 
 	return 0;
 }
+
+/**
+ * write_number - Convert number to big-endian format
+ *
+ * @p:		Buffer to write the number to
+ * @value:	Number to convert
+ * @cells:	Number of cells
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+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.
+ */
+static int setup_ima_buffer(const struct kimage *image, void *fdt,
+			    int chosen_node)
+{
+	int ret, addr_cells, size_cells, entry_size;
+	u8 value[16];
+
+	if (!image->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->ima_buffer_addr, addr_cells);
+	if (ret)
+		return ret;
+
+	ret = write_number(value + 4 * addr_cells, image->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->ima_buffer_addr,
+			      image->ima_buffer_size);
+	if (ret)
+		return -EINVAL;
+
+	pr_debug("IMA buffer at 0x%llx, size = 0x%zx\n",
+		 image->ima_buffer_addr, image->ima_buffer_size);
+
+	return 0;
+}
+#else /* CONFIG_IMA_KEXEC */
+static inline int setup_ima_buffer(const struct kimage *image, void *fdt,
+				   int chosen_node)
+{
+	return 0;
+}
 #endif /* CONFIG_IMA_KEXEC */
 
 /*
@@ -270,6 +504,11 @@ void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
 	}
 
 	ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0);
+	if (ret)
+		goto out;
+
+	remove_ima_buffer(fdt, chosen_node);
+	ret = setup_ima_buffer(image, fdt, fdt_path_offset(fdt, "/chosen"));
 
 out:
 	if (ret) {
diff --git a/include/linux/of.h b/include/linux/of.h
index 03e0e694be29..9041fc286335 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -578,6 +578,8 @@ int of_ima_add_kexec_buffer(struct kimage *image,
 			    unsigned long load_addr, size_t size);
 #endif /* CONFIG_IMA_KEXEC */
 
+int ima_get_kexec_buffer(void **addr, size_t *size);
+int ima_free_kexec_buffer(void);
 #else /* CONFIG_OF */
 
 static inline void of_core_init(void)
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index aa312472c7c5..fdae37fa7051 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -24,10 +24,6 @@
 
 #include "../integrity.h"
 
-#ifdef CONFIG_HAVE_IMA_KEXEC
-#include <asm/ima.h>
-#endif
-
 enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN,
 		     IMA_SHOW_BINARY_OLD_STRING_FMT, IMA_SHOW_ASCII };
 enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8, TPM_PCR10 = 10 };
-- 
2.30.0

[PATCH v17 08/10] kexec: Use fdt_appendprop_addrrange() to add ima buffer to FDT

[Lakshmi Ramasubramanian]

fdt_appendprop_addrrange() function adds a property, with the given name,
to the device tree at the given node offset, and also sets the address
and size of the property.  This function should be used to add
"linux,ima-kexec-buffer" property to the device tree and set the address
and size of the IMA measurement buffer, instead of using custom function.

Use fdt_appendprop_addrrange() to add  "linux,ima-kexec-buffer" property
to the device tree.  This property holds the address and size of
the IMA measurement buffer that needs to be passed from the current
kernel to the next kernel across kexec system call.

Remove custom code that is used in setup_ima_buffer() to add
"linux,ima-kexec-buffer" property to the device tree.

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>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
---
 drivers/of/kexec.c | 57 ++++------------------------------------------
 1 file changed, 5 insertions(+), 52 deletions(-)

diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index c601b5af4a88..c53746b9b168 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -232,36 +232,6 @@ int of_ima_add_kexec_buffer(struct kimage *image,
 	return 0;
 }
 
-/**
- * write_number - Convert number to big-endian format
- *
- * @p:		Buffer to write the number to
- * @value:	Number to convert
- * @cells:	Number of cells
- *
- * Return: 0 on success, or negative errno on error.
- */
-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.
@@ -273,32 +243,15 @@ static int write_number(void *p, u64 value, int cells)
 static int setup_ima_buffer(const struct kimage *image, void *fdt,
 			    int chosen_node)
 {
-	int ret, addr_cells, size_cells, entry_size;
-	u8 value[16];
+	int ret;
 
 	if (!image->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->ima_buffer_addr, addr_cells);
-	if (ret)
-		return ret;
-
-	ret = write_number(value + 4 * addr_cells, image->ima_buffer_size,
-			   size_cells);
-	if (ret)
-		return ret;
-
-	ret = fdt_setprop(fdt, chosen_node, "linux,ima-kexec-buffer", value,
-			  entry_size);
+	ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+				       "linux,ima-kexec-buffer",
+				       image->ima_buffer_addr,
+				       image->ima_buffer_size);
 	if (ret < 0)
 		return -EINVAL;
 
-- 
2.30.0

[PATCH v17 09/10] powerpc: Delete unused function delete_fdt_mem_rsv()

[Lakshmi Ramasubramanian]

delete_fdt_mem_rsv() defined in "arch/powerpc/kexec/file_load.c"
has been renamed to fdt_find_and_del_mem_rsv(), and moved to
"drivers/of/kexec.c".

Remove delete_fdt_mem_rsv() in "arch/powerpc/kexec/file_load.c".

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>
---
 arch/powerpc/include/asm/kexec.h |  1 -
 arch/powerpc/kexec/file_load.c   | 32 --------------------------------
 2 files changed, 33 deletions(-)

diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index 2b87993f6e66..e543593da1e1 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -119,7 +119,6 @@ char *setup_kdump_cmdline(struct kimage *image, char *cmdline,
 int setup_purgatory(struct kimage *image, const void *slave_code,
 		    const void *fdt, unsigned long kernel_load_addr,
 		    unsigned long fdt_load_addr);
-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 bd8b956aafc3..6f75a45f14c5 100644
--- a/arch/powerpc/kexec/file_load.c
+++ b/arch/powerpc/kexec/file_load.c
@@ -107,35 +107,3 @@ 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;
-}
-- 
2.30.0

[PATCH v17 10/10] arm64: Enable passing IMA log to next kernel on kexec

[Lakshmi Ramasubramanian]

Update CONFIG_KEXEC_FILE to select CONFIG_HAVE_IMA_KEXEC, if CONFIG_IMA
is enabled, to indicate that the IMA measurement log information is
present in the device tree for ARM64.

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>
Suggested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
---
 arch/arm64/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 05e17351e4f3..8a93573cebb6 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1093,6 +1093,7 @@ config KEXEC
 config KEXEC_FILE
 	bool "kexec file based system call"
 	select KEXEC_CORE
+	select HAVE_IMA_KEXEC if IMA
 	help
 	  This is new version of kexec system call. This system call is
 	  file based and takes file descriptors as system call argument
-- 
2.30.0

Re: [PATCH v17 00/10] Carry forward IMA measurement log on kexec on ARM64

[Rob Herring]

On Tue, Feb 09, 2021 at 10:21:50AM -0800, Lakshmi Ramasubramanian wrote:
> On kexec file load Integrity Measurement Architecture (IMA) subsystem
> may verify the IMA signature of the kernel and initramfs, and measure
> it.  The command line parameters passed to the kernel in the kexec call
> may also be measured by IMA.  A remote attestation service can verify
> a TPM quote based on the TPM event log, the IMA measurement list, and
> the TPM PCR data.  This can be achieved only if the IMA measurement log
> is carried over from the current kernel to the next kernel across
> the kexec call.
> 
> powerpc already supports carrying forward the IMA measurement log on
> kexec.  This patch set adds support for carrying forward the IMA
> measurement log on kexec on ARM64.
> 
> This patch set moves the platform independent code defined for powerpc
> such that it can be reused for other platforms as well.  A chosen node
> "linux,ima-kexec-buffer" is added to the DTB for ARM64 to hold
> the address and the size of the memory reserved to carry
> the IMA measurement log.
> 
> This patch set has been tested for ARM64 platform using QEMU.
> I would like help from the community for testing this change on powerpc.
> Thanks.
> 
> This patch set is based on
> commit 96acc833dec8 ("ima: Free IMA measurement buffer after kexec syscall")
> in https://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git
> "next-integrity" branch.

Is that a hard dependency still? Given this is now almost entirely 
deleting arch code and adding drivers/of/ code, I was going to apply it.

Rob

Re: [PATCH v17 05/10] powerpc: Move ima buffer fields to struct kimage

[Rob Herring]

On Tue, Feb 09, 2021 at 10:21:55AM -0800, Lakshmi Ramasubramanian wrote:
> The fields ima_buffer_addr and ima_buffer_size in "struct kimage_arch"
> for powerpc are used to carry forward the IMA measurement list across
> kexec system call.  These fields are not architecture specific, but are
> currently limited to powerpc.
> 
> arch_ima_add_kexec_buffer() defined in "arch/powerpc/kexec/ima.c"
> sets ima_buffer_addr and ima_buffer_size for the kexec system call.
> This function does not have architecture specific code, but is
> currently limited to powerpc.
> 
> Move ima_buffer_addr and ima_buffer_size to "struct kimage".
> Rename arch_ima_add_kexec_buffer() to of_ima_add_kexec_buffer()
> and move it in drivers/of/kexec.c.
> 
> 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>
> Suggested-by: Will Deacon <will@kernel.org>
> ---
>  arch/powerpc/include/asm/ima.h     |  3 ---
>  arch/powerpc/include/asm/kexec.h   |  5 -----
>  arch/powerpc/kexec/ima.c           | 29 ++++++-----------------------
>  drivers/of/kexec.c                 | 23 +++++++++++++++++++++++
>  include/linux/kexec.h              |  3 +++
>  include/linux/of.h                 |  5 +++++
>  security/integrity/ima/ima_kexec.c |  3 ++-
>  7 files changed, 39 insertions(+), 32 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/ima.h b/arch/powerpc/include/asm/ima.h
> index ead488cf3981..51f64fd06c19 100644
> --- a/arch/powerpc/include/asm/ima.h
> +++ b/arch/powerpc/include/asm/ima.h
> @@ -14,9 +14,6 @@ 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,
> diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
> index bdd0ddb9ac4d..ecf88533d6b4 100644
> --- a/arch/powerpc/include/asm/kexec.h
> +++ b/arch/powerpc/include/asm/kexec.h
> @@ -112,11 +112,6 @@ struct kimage_arch {
>  	unsigned long elf_headers_sz;
>  	void *elf_headers;
>  	void *fdt;
> -
> -#ifdef CONFIG_IMA_KEXEC
> -	phys_addr_t ima_buffer_addr;
> -	size_t ima_buffer_size;
> -#endif
>  };
>  
>  char *setup_kdump_cmdline(struct kimage *image, char *cmdline,
> diff --git a/arch/powerpc/kexec/ima.c b/arch/powerpc/kexec/ima.c
> index 720e50e490b6..ed38125e2f87 100644
> --- a/arch/powerpc/kexec/ima.c
> +++ b/arch/powerpc/kexec/ima.c
> @@ -128,23 +128,6 @@ void remove_ima_buffer(void *fdt, int chosen_node)
>  }
>  
>  #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) {
> @@ -180,7 +163,7 @@ int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node)
>  	u8 value[16];
>  
>  	remove_ima_buffer(fdt, chosen_node);
> -	if (!image->arch.ima_buffer_size)
> +	if (!image->ima_buffer_size)
>  		return 0;
>  
>  	ret = get_addr_size_cells(&addr_cells, &size_cells);
> @@ -192,11 +175,11 @@ int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node)
>  	if (entry_size > sizeof(value))
>  		return -EINVAL;
>  
> -	ret = write_number(value, image->arch.ima_buffer_addr, addr_cells);
> +	ret = write_number(value, image->ima_buffer_addr, addr_cells);
>  	if (ret)
>  		return ret;
>  
> -	ret = write_number(value + 4 * addr_cells, image->arch.ima_buffer_size,
> +	ret = write_number(value + 4 * addr_cells, image->ima_buffer_size,
>  			   size_cells);
>  	if (ret)
>  		return ret;
> @@ -206,13 +189,13 @@ int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node)
>  	if (ret < 0)
>  		return -EINVAL;
>  
> -	ret = fdt_add_mem_rsv(fdt, image->arch.ima_buffer_addr,
> -			      image->arch.ima_buffer_size);
> +	ret = fdt_add_mem_rsv(fdt, image->ima_buffer_addr,
> +			      image->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);
> +		 image->ima_buffer_addr, image->ima_buffer_size);
>  
>  	return 0;
>  }
> diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
> index 469e09613cdd..9f33d215b9f2 100644
> --- a/drivers/of/kexec.c
> +++ b/drivers/of/kexec.c
> @@ -63,6 +63,29 @@ static int fdt_find_and_del_mem_rsv(void *fdt, unsigned long start, unsigned lon
>  	return -ENOENT;
>  }
>  
> +#ifdef CONFIG_IMA_KEXEC
> +/**
> + * of_ima_add_kexec_buffer - Add IMA buffer for next kernel
> + *
> + * @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
> + *
> + * Use this function to pass on the IMA buffer information to
> + * the next kernel across kexec system call.
> + *
> + * Return: 0 on success, negative errno on error.
> + */
> +int of_ima_add_kexec_buffer(struct kimage *image,
> +			    unsigned long load_addr, size_t size)
> +{
> +	image->ima_buffer_addr = load_addr;
> +	image->ima_buffer_size = size;
> +

There's nothing DT specific about this function, so this is the wrong 
place for it. I would just remove it and directly set the members.

Rob

Re: [PATCH v17 02/10] of: Add a common kexec FDT setup function

[Rob Herring]

On Tue, Feb 09, 2021 at 10:21:52AM -0800, Lakshmi Ramasubramanian wrote:
> 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_alloc_and_setup_fdt() and move it to "drivers/of/kexec.c".
> 
> Signed-off-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
> ---
>  drivers/of/Makefile |   6 ++
>  drivers/of/kexec.c  | 258 ++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/of.h  |  13 +++
>  3 files changed, 277 insertions(+)
>  create mode 100644 drivers/of/kexec.c
> 
> diff --git a/drivers/of/Makefile b/drivers/of/Makefile
> index 6e1e5212f058..c13b982084a3 100644
> --- a/drivers/of/Makefile
> +++ b/drivers/of/Makefile
> @@ -14,4 +14,10 @@ obj-$(CONFIG_OF_RESOLVE)  += resolver.o
>  obj-$(CONFIG_OF_OVERLAY) += overlay.o
>  obj-$(CONFIG_OF_NUMA) += of_numa.o
>  
> +ifdef CONFIG_KEXEC_FILE
> +ifdef CONFIG_OF_FLATTREE
> +obj-y	+= kexec.o
> +endif
> +endif
> +
>  obj-$(CONFIG_OF_UNITTEST) += unittest-data/
> diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
> new file mode 100644
> index 000000000000..469e09613cdd
> --- /dev/null
> +++ b/drivers/of/kexec.c
> @@ -0,0 +1,258 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * 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>
> +
> +/* 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
> +
> +/**
> + * 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.
> + */
> +static int fdt_find_and_del_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++) {
> +		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_alloc_and_setup_fdt - Alloc and setup a new Flattened Device Tree
> + *
> + * @image:		kexec image being loaded.
> + * @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: fdt on success, or NULL errno on error.
> + */
> +void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
> +				   unsigned long initrd_load_addr,
> +				   unsigned long initrd_len,
> +				   const char *cmdline)
> +{
> +	void *fdt;
> +	int ret, chosen_node;
> +	const void *prop;
> +	unsigned long fdt_size;
> +
> +	fdt_size = fdt_totalsize(initial_boot_params) +
> +		   (cmdline ? strlen(cmdline) : 0) +
> +		   FDT_EXTRA_SPACE;
> +
> +	fdt = kvmalloc(fdt_size, GFP_KERNEL);
> +	if (!fdt)
> +		return NULL;
> +
> +	ret = fdt_open_into(initial_boot_params, fdt, fdt_size);
> +	if (ret < 0) {
> +		pr_err("Error %d setting up the new device tree.\n", ret);
> +		goto out;
> +	}
> +
> +	/* 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) {
> +		pr_err("Error removing memory reservation.\n");
> +		goto out;
> +	}
> +
> +	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) {
> +			ret = -EINVAL;
> +			goto out;
> +		}
> +
> +		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)
> +			goto out;
> +	}
> +
> +	/* 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) {
> +		kvfree(fdt);
> +		fdt = NULL;
> +	}
> +
> +	return fdt;
> +}
> diff --git a/include/linux/of.h b/include/linux/of.h
> index 4b27c9a27df3..f0eff5e84353 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -560,6 +560,19 @@ int of_map_id(struct device_node *np, u32 id,
>  
>  phys_addr_t of_dma_get_max_cpu_address(struct device_node *np);
>  
> +/*
> + * Additional space needed for the buffer to build the new FDT
> + * so that we can add initrd, bootargs, kaslr-seed, rng-seed,
> + * userable-memory-range and elfcorehdr.
> + */
> +#define FDT_EXTRA_SPACE 0x1000

No need for this to be public now. Move it to of/kexec.c.

Rob

Re: [PATCH v17 03/10] arm64: Use common of_kexec_alloc_and_setup_fdt()

[Will Deacon]

On Tue, Feb 09, 2021 at 10:21:53AM -0800, Lakshmi Ramasubramanian wrote:
> From: Rob Herring <robh@kernel.org>
> 
> The code for setting up the /chosen node in the device tree
> and updating the memory reservation for the next kernel has been
> moved to of_kexec_alloc_and_setup_fdt() defined in "drivers/of/kexec.c".
> 
> Use the common of_kexec_alloc_and_setup_fdt() to setup the device tree
> and update the memory reservation for kexec for arm64.
> 
> Signed-off-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
> ---
>  arch/arm64/kernel/machine_kexec_file.c | 180 ++-----------------------
>  1 file changed, 8 insertions(+), 172 deletions(-)

I mean, of course I'm going to Ack that!

Acked-by: Will Deacon <will@kernel.org>

Will

Re: [PATCH v17 00/10] Carry forward IMA measurement log on kexec on ARM64

[Lakshmi Ramasubramanian]

On 2/10/21 9:15 AM, Rob Herring wrote:
> On Tue, Feb 09, 2021 at 10:21:50AM -0800, Lakshmi Ramasubramanian wrote:
>> On kexec file load Integrity Measurement Architecture (IMA) subsystem
>> may verify the IMA signature of the kernel and initramfs, and measure
>> it.  The command line parameters passed to the kernel in the kexec call
>> may also be measured by IMA.  A remote attestation service can verify
>> a TPM quote based on the TPM event log, the IMA measurement list, and
>> the TPM PCR data.  This can be achieved only if the IMA measurement log
>> is carried over from the current kernel to the next kernel across
>> the kexec call.
>>
>> powerpc already supports carrying forward the IMA measurement log on
>> kexec.  This patch set adds support for carrying forward the IMA
>> measurement log on kexec on ARM64.
>>
>> This patch set moves the platform independent code defined for powerpc
>> such that it can be reused for other platforms as well.  A chosen node
>> "linux,ima-kexec-buffer" is added to the DTB for ARM64 to hold
>> the address and the size of the memory reserved to carry
>> the IMA measurement log.
>>
>> This patch set has been tested for ARM64 platform using QEMU.
>> I would like help from the community for testing this change on powerpc.
>> Thanks.
>>
>> This patch set is based on
>> commit 96acc833dec8 ("ima: Free IMA measurement buffer after kexec syscall")
>> in https://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git
>> "next-integrity" branch.
> 
> Is that a hard dependency still? Given this is now almost entirely
> deleting arch code and adding drivers/of/ code, I was going to apply it.
> 

I tried applying the patches in Linus' mainline branch -
PATCH #5 0005-powerpc-Move-ima-buffer-fields-to-struct-kimage.patch 
doesn't apply.

But if I apply the dependent patch set (link given below), all the 
patches in this patch set apply fine.

https://patchwork.kernel.org/project/linux-integrity/patch/20210204174951.25771-2-nramas@linux.microsoft.com/

thanks,
  -lakshmi

Re: [PATCH v17 02/10] of: Add a common kexec FDT setup function

[Lakshmi Ramasubramanian]

On 2/10/21 9:23 AM, Rob Herring wrote:
> On Tue, Feb 09, 2021 at 10:21:52AM -0800, Lakshmi Ramasubramanian wrote:
>> 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_alloc_and_setup_fdt() and move it to "drivers/of/kexec.c".
>>
>> Signed-off-by: Rob Herring <robh@kernel.org>
>> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
>> ---
>>   drivers/of/Makefile |   6 ++
>>   drivers/of/kexec.c  | 258 ++++++++++++++++++++++++++++++++++++++++++++
>>   include/linux/of.h  |  13 +++
>>   3 files changed, 277 insertions(+)
>>   create mode 100644 drivers/of/kexec.c


>> diff --git a/include/linux/of.h b/include/linux/of.h
>> index 4b27c9a27df3..f0eff5e84353 100644
>> --- a/include/linux/of.h
>> +++ b/include/linux/of.h
>> @@ -560,6 +560,19 @@ int of_map_id(struct device_node *np, u32 id,
>>   
>>   phys_addr_t of_dma_get_max_cpu_address(struct device_node *np);
>>   
>> +/*
>> + * Additional space needed for the buffer to build the new FDT
>> + * so that we can add initrd, bootargs, kaslr-seed, rng-seed,
>> + * userable-memory-range and elfcorehdr.
>> + */
>> +#define FDT_EXTRA_SPACE 0x1000
> 
> No need for this to be public now. Move it to of/kexec.c.
> 

Will do.

  -lakshmi

Re: [PATCH v17 05/10] powerpc: Move ima buffer fields to struct kimage

[Lakshmi Ramasubramanian]

On 2/10/21 9:20 AM, Rob Herring wrote:
> On Tue, Feb 09, 2021 at 10:21:55AM -0800, Lakshmi Ramasubramanian wrote:
>> The fields ima_buffer_addr and ima_buffer_size in "struct kimage_arch"
>> for powerpc are used to carry forward the IMA measurement list across
>> kexec system call.  These fields are not architecture specific, but are
>> currently limited to powerpc.
>>
>> arch_ima_add_kexec_buffer() defined in "arch/powerpc/kexec/ima.c"
>> sets ima_buffer_addr and ima_buffer_size for the kexec system call.
>> This function does not have architecture specific code, but is
>> currently limited to powerpc.
>>
>> Move ima_buffer_addr and ima_buffer_size to "struct kimage".
>> Rename arch_ima_add_kexec_buffer() to of_ima_add_kexec_buffer()
>> and move it in drivers/of/kexec.c.
>>
>> 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>
>> Suggested-by: Will Deacon <will@kernel.org>
>> ---
>>   arch/powerpc/include/asm/ima.h     |  3 ---
>>   arch/powerpc/include/asm/kexec.h   |  5 -----
>>   arch/powerpc/kexec/ima.c           | 29 ++++++-----------------------
>>   drivers/of/kexec.c                 | 23 +++++++++++++++++++++++
>>   include/linux/kexec.h              |  3 +++
>>   include/linux/of.h                 |  5 +++++
>>   security/integrity/ima/ima_kexec.c |  3 ++-
>>   7 files changed, 39 insertions(+), 32 deletions(-)

>> diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
>> index 469e09613cdd..9f33d215b9f2 100644
>> --- a/drivers/of/kexec.c
>> +++ b/drivers/of/kexec.c
>> @@ -63,6 +63,29 @@ static int fdt_find_and_del_mem_rsv(void *fdt, unsigned long start, unsigned lon
>>   	return -ENOENT;
>>   }
>>   
>> +#ifdef CONFIG_IMA_KEXEC
>> +/**
>> + * of_ima_add_kexec_buffer - Add IMA buffer for next kernel
>> + *
>> + * @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
>> + *
>> + * Use this function to pass on the IMA buffer information to
>> + * the next kernel across kexec system call.
>> + *
>> + * Return: 0 on success, negative errno on error.
>> + */
>> +int of_ima_add_kexec_buffer(struct kimage *image,
>> +			    unsigned long load_addr, size_t size)
>> +{
>> +	image->ima_buffer_addr = load_addr;
>> +	image->ima_buffer_size = size;
>> +
> 
> There's nothing DT specific about this function, so this is the wrong
> place for it. I would just remove it and directly set the members.

Will do.

  -lakshmi

Re: [PATCH v17 00/10] Carry forward IMA measurement log on kexec on ARM64

[Rob Herring]

On Wed, Feb 10, 2021 at 11:33 AM Lakshmi Ramasubramanian
<nramas@linux.microsoft.com> wrote:
>
> On 2/10/21 9:15 AM, Rob Herring wrote:
> > On Tue, Feb 09, 2021 at 10:21:50AM -0800, Lakshmi Ramasubramanian wrote:
> >> On kexec file load Integrity Measurement Architecture (IMA) subsystem
> >> may verify the IMA signature of the kernel and initramfs, and measure
> >> it.  The command line parameters passed to the kernel in the kexec call
> >> may also be measured by IMA.  A remote attestation service can verify
> >> a TPM quote based on the TPM event log, the IMA measurement list, and
> >> the TPM PCR data.  This can be achieved only if the IMA measurement log
> >> is carried over from the current kernel to the next kernel across
> >> the kexec call.
> >>
> >> powerpc already supports carrying forward the IMA measurement log on
> >> kexec.  This patch set adds support for carrying forward the IMA
> >> measurement log on kexec on ARM64.
> >>
> >> This patch set moves the platform independent code defined for powerpc
> >> such that it can be reused for other platforms as well.  A chosen node
> >> "linux,ima-kexec-buffer" is added to the DTB for ARM64 to hold
> >> the address and the size of the memory reserved to carry
> >> the IMA measurement log.
> >>
> >> This patch set has been tested for ARM64 platform using QEMU.
> >> I would like help from the community for testing this change on powerpc.
> >> Thanks.
> >>
> >> This patch set is based on
> >> commit 96acc833dec8 ("ima: Free IMA measurement buffer after kexec syscall")
> >> in https://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git
> >> "next-integrity" branch.
> >
> > Is that a hard dependency still? Given this is now almost entirely
> > deleting arch code and adding drivers/of/ code, I was going to apply it.
> >
>
> I tried applying the patches in Linus' mainline branch -
> PATCH #5 0005-powerpc-Move-ima-buffer-fields-to-struct-kimage.patch
> doesn't apply.
>
> But if I apply the dependent patch set (link given below), all the
> patches in this patch set apply fine.
>
> https://patchwork.kernel.org/project/linux-integrity/patch/20210204174951.25771-2-nramas@linux.microsoft.com/

Ideally, we don't apply the same patch in 2 branches. It looks like
there's a conflict but no real dependence on the above patch (the
ima_buffer part). The conflict seems trivial enough that Linus can
resolve it in the merge window.

Or Mimi can take the whole thing if preferred?

Rob

Re: [PATCH v17 00/10] Carry forward IMA measurement log on kexec on ARM64

[Mimi Zohar]

On Wed, 2021-02-10 at 14:42 -0600, Rob Herring wrote:
> On Wed, Feb 10, 2021 at 11:33 AM Lakshmi Ramasubramanian
> <nramas@linux.microsoft.com> wrote:
> >
> > On 2/10/21 9:15 AM, Rob Herring wrote:
> > > On Tue, Feb 09, 2021 at 10:21:50AM -0800, Lakshmi Ramasubramanian wrote:
> > >> On kexec file load Integrity Measurement Architecture (IMA) subsystem
> > >> may verify the IMA signature of the kernel and initramfs, and measure
> > >> it.  The command line parameters passed to the kernel in the kexec call
> > >> may also be measured by IMA.  A remote attestation service can verify
> > >> a TPM quote based on the TPM event log, the IMA measurement list, and
> > >> the TPM PCR data.  This can be achieved only if the IMA measurement log
> > >> is carried over from the current kernel to the next kernel across
> > >> the kexec call.
> > >>
> > >> powerpc already supports carrying forward the IMA measurement log on
> > >> kexec.  This patch set adds support for carrying forward the IMA
> > >> measurement log on kexec on ARM64.
> > >>
> > >> This patch set moves the platform independent code defined for powerpc
> > >> such that it can be reused for other platforms as well.  A chosen node
> > >> "linux,ima-kexec-buffer" is added to the DTB for ARM64 to hold
> > >> the address and the size of the memory reserved to carry
> > >> the IMA measurement log.
> > >>
> > >> This patch set has been tested for ARM64 platform using QEMU.
> > >> I would like help from the community for testing this change on powerpc.
> > >> Thanks.
> > >>
> > >> This patch set is based on
> > >> commit 96acc833dec8 ("ima: Free IMA measurement buffer after kexec syscall")
> > >> in https://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git
> > >> "next-integrity" branch.
> > >
> > > Is that a hard dependency still? Given this is now almost entirely
> > > deleting arch code and adding drivers/of/ code, I was going to apply it.
> > >
> >
> > I tried applying the patches in Linus' mainline branch -
> > PATCH #5 0005-powerpc-Move-ima-buffer-fields-to-struct-kimage.patch
> > doesn't apply.
> >
> > But if I apply the dependent patch set (link given below), all the
> > patches in this patch set apply fine.
> >
> > https://patchwork.kernel.org/project/linux-integrity/patch/20210204174951.25771-2-nramas@linux.microsoft.com/
> 
> Ideally, we don't apply the same patch in 2 branches. It looks like
> there's a conflict but no real dependence on the above patch (the
> ima_buffer part). The conflict seems trivial enough that Linus can
> resolve it in the merge window.
> 
> Or Mimi can take the whole thing if preferred?

How about I create a topic branch with just the two patches, allowing
both of us to merge it?   There shouldn't be a problem with re-writing
next-integrity history.

Mimi

Re: [PATCH v17 00/10] Carry forward IMA measurement log on kexec on ARM64

[Mimi Zohar]

On Wed, 2021-02-10 at 15:55 -0500, Mimi Zohar wrote:
> On Wed, 2021-02-10 at 14:42 -0600, Rob Herring wrote:
> > On Wed, Feb 10, 2021 at 11:33 AM Lakshmi Ramasubramanian
> 
> > Ideally, we don't apply the same patch in 2 branches. It looks like
> > there's a conflict but no real dependence on the above patch (the
> > ima_buffer part). The conflict seems trivial enough that Linus can
> > resolve it in the merge window.
> > 
> > Or Mimi can take the whole thing if preferred?
> 
> How about I create a topic branch with just the two patches, allowing
> both of us to merge it?   There shouldn't be a problem with re-writing
> next-integrity history.

The 2 patches are now in the ima-kexec-fixes branch.

Mimi

Re: [PATCH v17 00/10] Carry forward IMA measurement log on kexec on ARM64

[Lakshmi Ramasubramanian]

On 2/10/21 1:39 PM, Mimi Zohar wrote:
> On Wed, 2021-02-10 at 15:55 -0500, Mimi Zohar wrote:
>> On Wed, 2021-02-10 at 14:42 -0600, Rob Herring wrote:
>>> On Wed, Feb 10, 2021 at 11:33 AM Lakshmi Ramasubramanian
>>
>>> Ideally, we don't apply the same patch in 2 branches. It looks like
>>> there's a conflict but no real dependence on the above patch (the
>>> ima_buffer part). The conflict seems trivial enough that Linus can
>>> resolve it in the merge window.
>>>
>>> Or Mimi can take the whole thing if preferred?
>>
>> How about I create a topic branch with just the two patches, allowing
>> both of us to merge it?   There shouldn't be a problem with re-writing
>> next-integrity history.
> 
> The 2 patches are now in the ima-kexec-fixes branch.
> 

Thanks a lot Mimi.

Rob - I will address the 2 comments you'd provided today, and build the 
patches in ima-kexec-fixes branch.

If you have more comments in the v17 patches, please let me know.

thanks,
  -lakshmi

Re: [PATCH v17 02/10] of: Add a common kexec FDT setup function

[Thiago Jung Bauermann]

Lakshmi Ramasubramanian <nramas@linux.microsoft.com> writes:

> 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_alloc_and_setup_fdt() and move it to "drivers/of/kexec.c".
>
> Signed-off-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
> ---
>  drivers/of/Makefile |   6 ++
>  drivers/of/kexec.c  | 258 ++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/of.h  |  13 +++
>  3 files changed, 277 insertions(+)
>  create mode 100644 drivers/of/kexec.c

Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>

-- 
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH v17 03/10] arm64: Use common of_kexec_alloc_and_setup_fdt()

[Thiago Jung Bauermann]

Lakshmi Ramasubramanian <nramas@linux.microsoft.com> writes:

> From: Rob Herring <robh@kernel.org>
>
> The code for setting up the /chosen node in the device tree
> and updating the memory reservation for the next kernel has been
> moved to of_kexec_alloc_and_setup_fdt() defined in "drivers/of/kexec.c".
>
> Use the common of_kexec_alloc_and_setup_fdt() to setup the device tree
> and update the memory reservation for kexec for arm64.
>
> Signed-off-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
> ---
>  arch/arm64/kernel/machine_kexec_file.c | 180 ++-----------------------
>  1 file changed, 8 insertions(+), 172 deletions(-)

Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>

-- 
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH v17 04/10] powerpc: Use common of_kexec_alloc_and_setup_fdt()

[Thiago Jung Bauermann]

Lakshmi Ramasubramanian <nramas@linux.microsoft.com> writes:

> From: Rob Herring <robh@kernel.org>
>
> The code for setting up the /chosen node in the device tree
> and updating the memory reservation for the next kernel has been
> moved to of_kexec_alloc_and_setup_fdt() defined in "drivers/of/kexec.c".
>
> Use the common of_kexec_alloc_and_setup_fdt() to setup the device tree
> and update the memory reservation for kexec for powerpc.
>
> Signed-off-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
> ---
>  arch/powerpc/include/asm/kexec.h  |   1 +
>  arch/powerpc/kexec/elf_64.c       |  29 ++++---
>  arch/powerpc/kexec/file_load.c    | 132 +-----------------------------
>  arch/powerpc/kexec/file_load_64.c |   3 +
>  4 files changed, 25 insertions(+), 140 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
> index dbf09d2f36d0..bdd0ddb9ac4d 100644
> --- a/arch/powerpc/include/asm/kexec.h
> +++ b/arch/powerpc/include/asm/kexec.h
> @@ -111,6 +111,7 @@ struct kimage_arch {
>  	unsigned long elf_headers_mem;
>  	unsigned long elf_headers_sz;
>  	void *elf_headers;
> +	void *fdt;
>  
>  #ifdef CONFIG_IMA_KEXEC
>  	phys_addr_t ima_buffer_addr;
> diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c
> index d0e459bb2f05..bfabd06f99b1 100644
> --- a/arch/powerpc/kexec/elf_64.c
> +++ b/arch/powerpc/kexec/elf_64.c
> @@ -19,6 +19,7 @@
>  #include <linux/kexec.h>
>  #include <linux/libfdt.h>
>  #include <linux/module.h>
> +#include <linux/of.h>
>  #include <linux/of_fdt.h>
>  #include <linux/slab.h>
>  #include <linux/types.h>
> @@ -29,7 +30,6 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
>  			unsigned long cmdline_len)
>  {
>  	int ret;
> -	unsigned int fdt_size;
>  	unsigned long kernel_load_addr;
>  	unsigned long initrd_load_addr = 0, fdt_load_addr;
>  	void *fdt;
> @@ -102,19 +102,13 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
>  		pr_debug("Loaded initrd at 0x%lx\n", initrd_load_addr);
>  	}
>  
> -	fdt_size = fdt_totalsize(initial_boot_params) * 2;
> -	fdt = kmalloc(fdt_size, GFP_KERNEL);
> +	fdt = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
> +					   initrd_len, cmdline);
>  	if (!fdt) {
>  		pr_err("Not enough memory for the device tree.\n");

This error string can be a bit misleading now, since
of_kexec_alloc_and_setup_fdt() can fail for reasons other than lack of
memory. I suggest changing it to the error string from fdt_open_into()
below:

		pr_err("Error setting up the new device tree.\n");

With this change:

Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>

And also:

Tested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>

-- 
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH v17 04/10] powerpc: Use common of_kexec_alloc_and_setup_fdt()

[Lakshmi Ramasubramanian]

On 2/10/21 5:42 PM, Thiago Jung Bauermann wrote:
> 
> Lakshmi Ramasubramanian <nramas@linux.microsoft.com> writes:
> 
>> From: Rob Herring <robh@kernel.org>
>>
>> The code for setting up the /chosen node in the device tree
>> and updating the memory reservation for the next kernel has been
>> moved to of_kexec_alloc_and_setup_fdt() defined in "drivers/of/kexec.c".
>>
>> Use the common of_kexec_alloc_and_setup_fdt() to setup the device tree
>> and update the memory reservation for kexec for powerpc.
>>
>> Signed-off-by: Rob Herring <robh@kernel.org>
>> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
>> ---
>>   arch/powerpc/include/asm/kexec.h  |   1 +
>>   arch/powerpc/kexec/elf_64.c       |  29 ++++---
>>   arch/powerpc/kexec/file_load.c    | 132 +-----------------------------
>>   arch/powerpc/kexec/file_load_64.c |   3 +
>>   4 files changed, 25 insertions(+), 140 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
>> index dbf09d2f36d0..bdd0ddb9ac4d 100644
>> --- a/arch/powerpc/include/asm/kexec.h
>> +++ b/arch/powerpc/include/asm/kexec.h
>> @@ -111,6 +111,7 @@ struct kimage_arch {
>>   	unsigned long elf_headers_mem;
>>   	unsigned long elf_headers_sz;
>>   	void *elf_headers;
>> +	void *fdt;
>>   
>>   #ifdef CONFIG_IMA_KEXEC
>>   	phys_addr_t ima_buffer_addr;
>> diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c
>> index d0e459bb2f05..bfabd06f99b1 100644
>> --- a/arch/powerpc/kexec/elf_64.c
>> +++ b/arch/powerpc/kexec/elf_64.c
>> @@ -19,6 +19,7 @@
>>   #include <linux/kexec.h>
>>   #include <linux/libfdt.h>
>>   #include <linux/module.h>
>> +#include <linux/of.h>
>>   #include <linux/of_fdt.h>
>>   #include <linux/slab.h>
>>   #include <linux/types.h>
>> @@ -29,7 +30,6 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
>>   			unsigned long cmdline_len)
>>   {
>>   	int ret;
>> -	unsigned int fdt_size;
>>   	unsigned long kernel_load_addr;
>>   	unsigned long initrd_load_addr = 0, fdt_load_addr;
>>   	void *fdt;
>> @@ -102,19 +102,13 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
>>   		pr_debug("Loaded initrd at 0x%lx\n", initrd_load_addr);
>>   	}
>>   
>> -	fdt_size = fdt_totalsize(initial_boot_params) * 2;
>> -	fdt = kmalloc(fdt_size, GFP_KERNEL);
>> +	fdt = of_kexec_alloc_and_setup_fdt(image, initrd_load_addr,
>> +					   initrd_len, cmdline);
>>   	if (!fdt) {
>>   		pr_err("Not enough memory for the device tree.\n");
> 
> This error string can be a bit misleading now, since
> of_kexec_alloc_and_setup_fdt() can fail for reasons other than lack of
> memory. I suggest changing it to the error string from fdt_open_into()
> below:
> 
> 		pr_err("Error setting up the new device tree.\n");
> 
> With this change:
Agreed - I will make this change.

> 
> Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
> 
> And also:
> 
> Tested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
> 

Thanks a lot for your help Thiago.

  -lakshmi

Re: [PATCH v17 06/10] powerpc: Enable passing IMA log to next kernel on kexec

[Thiago Jung Bauermann]

Lakshmi Ramasubramanian <nramas@linux.microsoft.com> writes:

> CONFIG_HAVE_IMA_KEXEC is enabled to indicate that the IMA measurement
> log information is present in the device tree. This should be selected
> only if CONFIG_IMA is enabled.
>
> Update CONFIG_KEXEC_FILE to select CONFIG_HAVE_IMA_KEXEC, if CONFIG_IMA
> is enabled, to indicate that the IMA measurement log information is
> present in the device tree for powerpc.
>
> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
> Suggested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
> ---
>  arch/powerpc/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>

-- 
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH v17 07/10] powerpc: Move arch independent ima kexec functions to drivers/of/kexec.c

[Thiago Jung Bauermann]

Lakshmi Ramasubramanian <nramas@linux.microsoft.com> writes:

> The functions defined in "arch/powerpc/kexec/ima.c" handle setting up
> and freeing the resources required to carry over the IMA measurement
> list from the current kernel to the next kernel across kexec system call.
> These functions do not have architecture specific code, but are
> currently limited to powerpc.
>
> Move remove_ima_buffer() and setup_ima_buffer() calls into
> of_kexec_alloc_and_setup_fdt() defined in "drivers/of/kexec.c".
>
> Move the remaining architecture independent functions from
> "arch/powerpc/kexec/ima.c" to "drivers/of/kexec.c".
> Delete "arch/powerpc/kexec/ima.c" and "arch/powerpc/include/asm/ima.h".
> Remove references to the deleted files and functions in powerpc and
> in ima.
>
> 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>
> ---
>  arch/powerpc/include/asm/ima.h    |  27 ----
>  arch/powerpc/include/asm/kexec.h  |   3 -
>  arch/powerpc/kexec/Makefile       |   7 -
>  arch/powerpc/kexec/file_load.c    |  25 ----
>  arch/powerpc/kexec/file_load_64.c |   4 -
>  arch/powerpc/kexec/ima.c          | 202 -------------------------
>  drivers/of/kexec.c                | 239 ++++++++++++++++++++++++++++++
>  include/linux/of.h                |   2 +
>  security/integrity/ima/ima.h      |   4 -
>  9 files changed, 241 insertions(+), 272 deletions(-)
>  delete mode 100644 arch/powerpc/include/asm/ima.h
>  delete mode 100644 arch/powerpc/kexec/ima.c

Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Tested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>

-- 
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH v17 09/10] powerpc: Delete unused function delete_fdt_mem_rsv()

[Thiago Jung Bauermann]

Lakshmi Ramasubramanian <nramas@linux.microsoft.com> writes:

> delete_fdt_mem_rsv() defined in "arch/powerpc/kexec/file_load.c"
> has been renamed to fdt_find_and_del_mem_rsv(), and moved to
> "drivers/of/kexec.c".
>
> Remove delete_fdt_mem_rsv() in "arch/powerpc/kexec/file_load.c".
>
> 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>
> ---
>  arch/powerpc/include/asm/kexec.h |  1 -
>  arch/powerpc/kexec/file_load.c   | 32 --------------------------------
>  2 files changed, 33 deletions(-)

Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>

-- 
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH v17 10/10] arm64: Enable passing IMA log to next kernel on kexec

[Thiago Jung Bauermann]

Lakshmi Ramasubramanian <nramas@linux.microsoft.com> writes:

> Update CONFIG_KEXEC_FILE to select CONFIG_HAVE_IMA_KEXEC, if CONFIG_IMA
> is enabled, to indicate that the IMA measurement log information is
> present in the device tree for ARM64.
>
> 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>
> Suggested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
> ---
>  arch/arm64/Kconfig | 1 +
>  1 file changed, 1 insertion(+)

Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>

-- 
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH v17 02/10] of: Add a common kexec FDT setup function

[Thiago Jung Bauermann]

There's actually a complication that I just noticed and needs to be
addressed. More below.

Lakshmi Ramasubramanian <nramas@linux.microsoft.com> writes:

> 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_alloc_and_setup_fdt() and move it to "drivers/of/kexec.c".
>
> Signed-off-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
> ---
>  drivers/of/Makefile |   6 ++
>  drivers/of/kexec.c  | 258 ++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/of.h  |  13 +++
>  3 files changed, 277 insertions(+)
>  create mode 100644 drivers/of/kexec.c
>
> diff --git a/drivers/of/Makefile b/drivers/of/Makefile
> index 6e1e5212f058..c13b982084a3 100644
> --- a/drivers/of/Makefile
> +++ b/drivers/of/Makefile
> @@ -14,4 +14,10 @@ obj-$(CONFIG_OF_RESOLVE)  += resolver.o
>  obj-$(CONFIG_OF_OVERLAY) += overlay.o
>  obj-$(CONFIG_OF_NUMA) += of_numa.o
>  
> +ifdef CONFIG_KEXEC_FILE
> +ifdef CONFIG_OF_FLATTREE
> +obj-y	+= kexec.o
> +endif
> +endif
> +
>  obj-$(CONFIG_OF_UNITTEST) += unittest-data/
> diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
> new file mode 100644
> index 000000000000..469e09613cdd
> --- /dev/null
> +++ b/drivers/of/kexec.c
> @@ -0,0 +1,258 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * 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>
> +
> +/* 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
> +
> +/**
> + * 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.
> + */
> +static int fdt_find_and_del_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++) {
> +		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_alloc_and_setup_fdt - Alloc and setup a new Flattened Device Tree
> + *
> + * @image:		kexec image being loaded.
> + * @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: fdt on success, or NULL errno on error.
> + */
> +void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
> +				   unsigned long initrd_load_addr,
> +				   unsigned long initrd_len,
> +				   const char *cmdline)
> +{
> +	void *fdt;
> +	int ret, chosen_node;
> +	const void *prop;
> +	unsigned long fdt_size;
> +
> +	fdt_size = fdt_totalsize(initial_boot_params) +
> +		   (cmdline ? strlen(cmdline) : 0) +
> +		   FDT_EXTRA_SPACE;

Just adding 4 KB to initial_boot_params won't be enough for crash
kernels on ppc64. The current powerpc code doubles the size of
initial_boot_params (which is normally larger than 4 KB) and even that
isn't enough. A patch was added to powerpc/next today which uses a more
precise (but arch-specific) formula:

https://lore.kernel.org/linuxppc-dev/161243826811.119001.14083048209224609814.stgit@hbathini/

So I believe we need a hook here where architectures can provide their
own specific calculation for the size of the fdt. Perhaps a weakly
defined function providing a default implementation which an
arch-specific file can override (a la arch_kexec_kernel_image_load())?

Then the powerpc specific hook would be the kexec_fdt_totalsize_ppc64()
function from the patch I linked above.

-- 
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH v17 02/10] of: Add a common kexec FDT setup function

[Lakshmi Ramasubramanian]

On 2/11/21 5:09 PM, Thiago Jung Bauermann wrote:
> 
> There's actually a complication that I just noticed and needs to be
> addressed. More below.
> 

<...>

>> +
>> +/*
>> + * of_kexec_alloc_and_setup_fdt - Alloc and setup a new Flattened Device Tree
>> + *
>> + * @image:		kexec image being loaded.
>> + * @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: fdt on success, or NULL errno on error.
>> + */
>> +void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
>> +				   unsigned long initrd_load_addr,
>> +				   unsigned long initrd_len,
>> +				   const char *cmdline)
>> +{
>> +	void *fdt;
>> +	int ret, chosen_node;
>> +	const void *prop;
>> +	unsigned long fdt_size;
>> +
>> +	fdt_size = fdt_totalsize(initial_boot_params) +
>> +		   (cmdline ? strlen(cmdline) : 0) +
>> +		   FDT_EXTRA_SPACE;
> 
> Just adding 4 KB to initial_boot_params won't be enough for crash
> kernels on ppc64. The current powerpc code doubles the size of
> initial_boot_params (which is normally larger than 4 KB) and even that
> isn't enough. A patch was added to powerpc/next today which uses a more
> precise (but arch-specific) formula:
> 
> https://lore.kernel.org/linuxppc-dev/161243826811.119001.14083048209224609814.stgit@hbathini/
> 
> So I believe we need a hook here where architectures can provide their
> own specific calculation for the size of the fdt. Perhaps a weakly
> defined function providing a default implementation which an
> arch-specific file can override (a la arch_kexec_kernel_image_load())?
> 
> Then the powerpc specific hook would be the kexec_fdt_totalsize_ppc64()
> function from the patch I linked above.
> 

Do you think it'd better to add "fdt_size" parameter to 
of_kexec_alloc_and_setup_fdt() so that the caller can provide the 
desired FDT buffer size?

thanks,
  -lakshmi

Re: [PATCH v17 02/10] of: Add a common kexec FDT setup function

[Thiago Jung Bauermann]

Lakshmi Ramasubramanian <nramas@linux.microsoft.com> writes:

> On 2/11/21 5:09 PM, Thiago Jung Bauermann wrote:
>> There's actually a complication that I just noticed and needs to be
>> addressed. More below.
>> 
>
> <...>
>
>>> +
>>> +/*
>>> + * of_kexec_alloc_and_setup_fdt - Alloc and setup a new Flattened Device Tree
>>> + *
>>> + * @image:		kexec image being loaded.
>>> + * @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: fdt on success, or NULL errno on error.
>>> + */
>>> +void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
>>> +				   unsigned long initrd_load_addr,
>>> +				   unsigned long initrd_len,
>>> +				   const char *cmdline)
>>> +{
>>> +	void *fdt;
>>> +	int ret, chosen_node;
>>> +	const void *prop;
>>> +	unsigned long fdt_size;
>>> +
>>> +	fdt_size = fdt_totalsize(initial_boot_params) +
>>> +		   (cmdline ? strlen(cmdline) : 0) +
>>> +		   FDT_EXTRA_SPACE;
>> Just adding 4 KB to initial_boot_params won't be enough for crash
>> kernels on ppc64. The current powerpc code doubles the size of
>> initial_boot_params (which is normally larger than 4 KB) and even that
>> isn't enough. A patch was added to powerpc/next today which uses a more
>> precise (but arch-specific) formula:
>> https://lore.kernel.org/linuxppc-dev/161243826811.119001.14083048209224609814.stgit@hbathini/
>> So I believe we need a hook here where architectures can provide their
>> own specific calculation for the size of the fdt. Perhaps a weakly
>> defined function providing a default implementation which an
>> arch-specific file can override (a la arch_kexec_kernel_image_load())?
>> Then the powerpc specific hook would be the kexec_fdt_totalsize_ppc64()
>> function from the patch I linked above.
>> 
>
> Do you think it'd better to add "fdt_size" parameter to
> of_kexec_alloc_and_setup_fdt() so that the caller can provide the 
> desired FDT buffer size?

Yes, that is actually simpler and better than my idea. :-)

-- 
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH v17 02/10] of: Add a common kexec FDT setup function

[Rob Herring]

On Thu, Feb 11, 2021 at 7:17 PM Lakshmi Ramasubramanian
<nramas@linux.microsoft.com> wrote:
>
> On 2/11/21 5:09 PM, Thiago Jung Bauermann wrote:
> >
> > There's actually a complication that I just noticed and needs to be
> > addressed. More below.
> >
>
> <...>
>
> >> +
> >> +/*
> >> + * of_kexec_alloc_and_setup_fdt - Alloc and setup a new Flattened Device Tree
> >> + *
> >> + * @image:          kexec image being loaded.
> >> + * @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: fdt on success, or NULL errno on error.
> >> + */
> >> +void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
> >> +                               unsigned long initrd_load_addr,
> >> +                               unsigned long initrd_len,
> >> +                               const char *cmdline)
> >> +{
> >> +    void *fdt;
> >> +    int ret, chosen_node;
> >> +    const void *prop;
> >> +    unsigned long fdt_size;
> >> +
> >> +    fdt_size = fdt_totalsize(initial_boot_params) +
> >> +               (cmdline ? strlen(cmdline) : 0) +
> >> +               FDT_EXTRA_SPACE;
> >
> > Just adding 4 KB to initial_boot_params won't be enough for crash
> > kernels on ppc64. The current powerpc code doubles the size of
> > initial_boot_params (which is normally larger than 4 KB) and even that
> > isn't enough. A patch was added to powerpc/next today which uses a more
> > precise (but arch-specific) formula:
> >
> > https://lore.kernel.org/linuxppc-dev/161243826811.119001.14083048209224609814.stgit@hbathini/
> >
> > So I believe we need a hook here where architectures can provide their
> > own specific calculation for the size of the fdt. Perhaps a weakly
> > defined function providing a default implementation which an
> > arch-specific file can override (a la arch_kexec_kernel_image_load())?
> >
> > Then the powerpc specific hook would be the kexec_fdt_totalsize_ppc64()
> > function from the patch I linked above.
> >
>
> Do you think it'd better to add "fdt_size" parameter to
> of_kexec_alloc_and_setup_fdt() so that the caller can provide the
> desired FDT buffer size?

Yes, I guess so. But please define the param as extra size, not total
size. The kernel command line size addition can be in the common code.

The above change is also going to conflict, so I think this may have
to wait. Or I'll take the common and arm bits and powerpc can be
converted next cycle (or after the merge window).

Rob

Re: [PATCH v17 02/10] of: Add a common kexec FDT setup function

[Lakshmi Ramasubramanian]

On 2/12/21 6:38 AM, Rob Herring wrote:
> On Thu, Feb 11, 2021 at 7:17 PM Lakshmi Ramasubramanian
> <nramas@linux.microsoft.com> wrote:
>>
>> On 2/11/21 5:09 PM, Thiago Jung Bauermann wrote:
>>>
>>> There's actually a complication that I just noticed and needs to be
>>> addressed. More below.
>>>
>>
>> <...>
>>
>>>> +
>>>> +/*
>>>> + * of_kexec_alloc_and_setup_fdt - Alloc and setup a new Flattened Device Tree
>>>> + *
>>>> + * @image:          kexec image being loaded.
>>>> + * @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: fdt on success, or NULL errno on error.
>>>> + */
>>>> +void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
>>>> +                               unsigned long initrd_load_addr,
>>>> +                               unsigned long initrd_len,
>>>> +                               const char *cmdline)
>>>> +{
>>>> +    void *fdt;
>>>> +    int ret, chosen_node;
>>>> +    const void *prop;
>>>> +    unsigned long fdt_size;
>>>> +
>>>> +    fdt_size = fdt_totalsize(initial_boot_params) +
>>>> +               (cmdline ? strlen(cmdline) : 0) +
>>>> +               FDT_EXTRA_SPACE;
>>>
>>> Just adding 4 KB to initial_boot_params won't be enough for crash
>>> kernels on ppc64. The current powerpc code doubles the size of
>>> initial_boot_params (which is normally larger than 4 KB) and even that
>>> isn't enough. A patch was added to powerpc/next today which uses a more
>>> precise (but arch-specific) formula:
>>>
>>> https://lore.kernel.org/linuxppc-dev/161243826811.119001.14083048209224609814.stgit@hbathini/
>>>
>>> So I believe we need a hook here where architectures can provide their
>>> own specific calculation for the size of the fdt. Perhaps a weakly
>>> defined function providing a default implementation which an
>>> arch-specific file can override (a la arch_kexec_kernel_image_load())?
>>>
>>> Then the powerpc specific hook would be the kexec_fdt_totalsize_ppc64()
>>> function from the patch I linked above.
>>>
>>
>> Do you think it'd better to add "fdt_size" parameter to
>> of_kexec_alloc_and_setup_fdt() so that the caller can provide the
>> desired FDT buffer size?
> 
> Yes, I guess so. But please define the param as extra size, not total
> size. The kernel command line size addition can be in the common code.

Will do. Just to clarify -

The common code will do:

fdt_totalsize(initial_boot_params) + strlen(cmdline) + extra_fdt_size

The caller will pass "extra_fdt_size"
ARM64 => 4KB
PPC64 => fdt_totalsize(initial_boot_params) - which will be updated when 
the patch Thiago had referred to is merged.

> 
> The above change is also going to conflict, so I think this may have
> to wait. Or I'll take the common and arm bits and powerpc can be
> converted next cycle (or after the merge window).
> 

thanks.

  -lakshmi

Re: [PATCH v17 02/10] of: Add a common kexec FDT setup function

[Rob Herring]

On Fri, Feb 12, 2021 at 11:19 AM Lakshmi Ramasubramanian
<nramas@linux.microsoft.com> wrote:
>
> On 2/12/21 6:38 AM, Rob Herring wrote:
> > On Thu, Feb 11, 2021 at 7:17 PM Lakshmi Ramasubramanian
> > <nramas@linux.microsoft.com> wrote:
> >>
> >> On 2/11/21 5:09 PM, Thiago Jung Bauermann wrote:
> >>>
> >>> There's actually a complication that I just noticed and needs to be
> >>> addressed. More below.
> >>>
> >>
> >> <...>
> >>
> >>>> +
> >>>> +/*
> >>>> + * of_kexec_alloc_and_setup_fdt - Alloc and setup a new Flattened Device Tree
> >>>> + *
> >>>> + * @image:          kexec image being loaded.
> >>>> + * @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: fdt on success, or NULL errno on error.
> >>>> + */
> >>>> +void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
> >>>> +                               unsigned long initrd_load_addr,
> >>>> +                               unsigned long initrd_len,
> >>>> +                               const char *cmdline)
> >>>> +{
> >>>> +    void *fdt;
> >>>> +    int ret, chosen_node;
> >>>> +    const void *prop;
> >>>> +    unsigned long fdt_size;
> >>>> +
> >>>> +    fdt_size = fdt_totalsize(initial_boot_params) +
> >>>> +               (cmdline ? strlen(cmdline) : 0) +
> >>>> +               FDT_EXTRA_SPACE;
> >>>
> >>> Just adding 4 KB to initial_boot_params won't be enough for crash
> >>> kernels on ppc64. The current powerpc code doubles the size of
> >>> initial_boot_params (which is normally larger than 4 KB) and even that
> >>> isn't enough. A patch was added to powerpc/next today which uses a more
> >>> precise (but arch-specific) formula:
> >>>
> >>> https://lore.kernel.org/linuxppc-dev/161243826811.119001.14083048209224609814.stgit@hbathini/
> >>>
> >>> So I believe we need a hook here where architectures can provide their
> >>> own specific calculation for the size of the fdt. Perhaps a weakly
> >>> defined function providing a default implementation which an
> >>> arch-specific file can override (a la arch_kexec_kernel_image_load())?
> >>>
> >>> Then the powerpc specific hook would be the kexec_fdt_totalsize_ppc64()
> >>> function from the patch I linked above.
> >>>
> >>
> >> Do you think it'd better to add "fdt_size" parameter to
> >> of_kexec_alloc_and_setup_fdt() so that the caller can provide the
> >> desired FDT buffer size?
> >
> > Yes, I guess so. But please define the param as extra size, not total
> > size. The kernel command line size addition can be in the common code.
>
> Will do. Just to clarify -
>
> The common code will do:
>
> fdt_totalsize(initial_boot_params) + strlen(cmdline) + extra_fdt_size
>
> The caller will pass "extra_fdt_size"
> ARM64 => 4KB
> PPC64 => fdt_totalsize(initial_boot_params) - which will be updated when
> the patch Thiago had referred to is merged.

Yes, I'd leave the 4KB in there by default and arm64 use 0.

Rob

Re: [PATCH v17 02/10] of: Add a common kexec FDT setup function

[Lakshmi Ramasubramanian]

On 2/12/21 10:24 AM, Rob Herring wrote:
> On Fri, Feb 12, 2021 at 11:19 AM Lakshmi Ramasubramanian
> <nramas@linux.microsoft.com> wrote:
>>
>> On 2/12/21 6:38 AM, Rob Herring wrote:
>>> On Thu, Feb 11, 2021 at 7:17 PM Lakshmi Ramasubramanian
>>> <nramas@linux.microsoft.com> wrote:
>>>>
>>>> On 2/11/21 5:09 PM, Thiago Jung Bauermann wrote:
>>>>>
>>>>> There's actually a complication that I just noticed and needs to be
>>>>> addressed. More below.
>>>>>
>>>>
>>>> <...>
>>>>
>>>>>> +
>>>>>> +/*
>>>>>> + * of_kexec_alloc_and_setup_fdt - Alloc and setup a new Flattened Device Tree
>>>>>> + *
>>>>>> + * @image:          kexec image being loaded.
>>>>>> + * @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: fdt on success, or NULL errno on error.
>>>>>> + */
>>>>>> +void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
>>>>>> +                               unsigned long initrd_load_addr,
>>>>>> +                               unsigned long initrd_len,
>>>>>> +                               const char *cmdline)
>>>>>> +{
>>>>>> +    void *fdt;
>>>>>> +    int ret, chosen_node;
>>>>>> +    const void *prop;
>>>>>> +    unsigned long fdt_size;
>>>>>> +
>>>>>> +    fdt_size = fdt_totalsize(initial_boot_params) +
>>>>>> +               (cmdline ? strlen(cmdline) : 0) +
>>>>>> +               FDT_EXTRA_SPACE;
>>>>>
>>>>> Just adding 4 KB to initial_boot_params won't be enough for crash
>>>>> kernels on ppc64. The current powerpc code doubles the size of
>>>>> initial_boot_params (which is normally larger than 4 KB) and even that
>>>>> isn't enough. A patch was added to powerpc/next today which uses a more
>>>>> precise (but arch-specific) formula:
>>>>>
>>>>> https://lore.kernel.org/linuxppc-dev/161243826811.119001.14083048209224609814.stgit@hbathini/
>>>>>
>>>>> So I believe we need a hook here where architectures can provide their
>>>>> own specific calculation for the size of the fdt. Perhaps a weakly
>>>>> defined function providing a default implementation which an
>>>>> arch-specific file can override (a la arch_kexec_kernel_image_load())?
>>>>>
>>>>> Then the powerpc specific hook would be the kexec_fdt_totalsize_ppc64()
>>>>> function from the patch I linked above.
>>>>>
>>>>
>>>> Do you think it'd better to add "fdt_size" parameter to
>>>> of_kexec_alloc_and_setup_fdt() so that the caller can provide the
>>>> desired FDT buffer size?
>>>
>>> Yes, I guess so. But please define the param as extra size, not total
>>> size. The kernel command line size addition can be in the common code.
>>
>> Will do. Just to clarify -
>>
>> The common code will do:
>>
>> fdt_totalsize(initial_boot_params) + strlen(cmdline) + extra_fdt_size
>>
>> The caller will pass "extra_fdt_size"
>> ARM64 => 4KB
>> PPC64 => fdt_totalsize(initial_boot_params) - which will be updated when
>> the patch Thiago had referred to is merged.
> 
> Yes, I'd leave the 4KB in there by default and arm64 use 0.
> 

Sounds good.

common:
fdt_totalsize(initial_boot_params) + strlen(cmdline) + 0x1000 + extra

arm64 => 0 for extra
ppc => fdt_totalsize(initial_boot_params) for extra.

  -lakshmi

Re: [PATCH v17 02/10] of: Add a common kexec FDT setup function

[Thiago Jung Bauermann]

Lakshmi Ramasubramanian <nramas@linux.microsoft.com> writes:

> On 2/12/21 10:24 AM, Rob Herring wrote:
>> On Fri, Feb 12, 2021 at 11:19 AM Lakshmi Ramasubramanian
>> <nramas@linux.microsoft.com> wrote:
>>>
>>> On 2/12/21 6:38 AM, Rob Herring wrote:
>>>> On Thu, Feb 11, 2021 at 7:17 PM Lakshmi Ramasubramanian
>>>> <nramas@linux.microsoft.com> wrote:
>>>>>
>>>>> On 2/11/21 5:09 PM, Thiago Jung Bauermann wrote:
>>>>>>
>>>>>> There's actually a complication that I just noticed and needs to be
>>>>>> addressed. More below.
>>>>>>
>>>>>
>>>>> <...>
>>>>>
>>>>>>> +
>>>>>>> +/*
>>>>>>> + * of_kexec_alloc_and_setup_fdt - Alloc and setup a new Flattened Device Tree
>>>>>>> + *
>>>>>>> + * @image:          kexec image being loaded.
>>>>>>> + * @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: fdt on success, or NULL errno on error.
>>>>>>> + */
>>>>>>> +void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
>>>>>>> +                               unsigned long initrd_load_addr,
>>>>>>> +                               unsigned long initrd_len,
>>>>>>> +                               const char *cmdline)
>>>>>>> +{
>>>>>>> +    void *fdt;
>>>>>>> +    int ret, chosen_node;
>>>>>>> +    const void *prop;
>>>>>>> +    unsigned long fdt_size;
>>>>>>> +
>>>>>>> +    fdt_size = fdt_totalsize(initial_boot_params) +
>>>>>>> +               (cmdline ? strlen(cmdline) : 0) +
>>>>>>> +               FDT_EXTRA_SPACE;
>>>>>>
>>>>>> Just adding 4 KB to initial_boot_params won't be enough for crash
>>>>>> kernels on ppc64. The current powerpc code doubles the size of
>>>>>> initial_boot_params (which is normally larger than 4 KB) and even that
>>>>>> isn't enough. A patch was added to powerpc/next today which uses a more
>>>>>> precise (but arch-specific) formula:
>>>>>>
>>>>>> https://lore.kernel.org/linuxppc-dev/161243826811.119001.14083048209224609814.stgit@hbathini/
>>>>>>
>>>>>> So I believe we need a hook here where architectures can provide their
>>>>>> own specific calculation for the size of the fdt. Perhaps a weakly
>>>>>> defined function providing a default implementation which an
>>>>>> arch-specific file can override (a la arch_kexec_kernel_image_load())?
>>>>>>
>>>>>> Then the powerpc specific hook would be the kexec_fdt_totalsize_ppc64()
>>>>>> function from the patch I linked above.
>>>>>>
>>>>>
>>>>> Do you think it'd better to add "fdt_size" parameter to
>>>>> of_kexec_alloc_and_setup_fdt() so that the caller can provide the
>>>>> desired FDT buffer size?
>>>>
>>>> Yes, I guess so. But please define the param as extra size, not total
>>>> size. The kernel command line size addition can be in the common code.
>>>
>>> Will do. Just to clarify -
>>>
>>> The common code will do:
>>>
>>> fdt_totalsize(initial_boot_params) + strlen(cmdline) + extra_fdt_size
>>>
>>> The caller will pass "extra_fdt_size"
>>> ARM64 => 4KB
>>> PPC64 => fdt_totalsize(initial_boot_params) - which will be updated when
>>> the patch Thiago had referred to is merged.
>> Yes, I'd leave the 4KB in there by default and arm64 use 0.
>> 
>
> Sounds good.
>
> common:
> fdt_totalsize(initial_boot_params) + strlen(cmdline) + 0x1000 + extra
>
> arm64 => 0 for extra
> ppc => fdt_totalsize(initial_boot_params) for extra.

Looks good to me.

-- 
Thiago Jung Bauermann
IBM Linux Technology Center