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[PATCH 0/9] kexec: add kexec_file_load() support

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  [PATCH 0/9] kexec: add kexec_file_load() support AKASHI Takahiro <takahiro.akashi@linaro.org> - 2017-09-08 05:20 +0200
    [PATCH 2/9] resource: add walk_system_ram_res_rev() AKASHI Takahiro <takahiro.akashi@linaro.org> - 2017-09-08 05:20 +0200
    [PATCH 6/9] arm64: kexec_file: load initrd, device-tree and purgatory segments AKASHI Takahiro <takahiro.akashi@linaro.org> - 2017-09-08 05:20 +0200
      Re: [PATCH 6/9] arm64: kexec_file: load initrd, device-tree and  purgatory segments Dave Young <dyoung@redhat.com> - 2017-09-11 08:50 +0200
        Re: [PATCH 6/9] arm64: kexec_file: load initrd, device-tree and  purgatory segments Dave Young <dyoung@redhat.com> - 2017-09-11 10:30 +0200
        Re: [PATCH 6/9] arm64: kexec_file: load initrd, device-tree and  purgatory segments AKASHI Takahiro <takahiro.akashi@linaro.org> - 2017-09-12 06:50 +0200
    [PATCH 7/9] arm64: kexec_file: set up for crash dump adding elf core header AKASHI Takahiro <takahiro.akashi@linaro.org> - 2017-09-08 05:20 +0200
    [PATCH 1/9] include: pe.h: remove message[] from mz header definition AKASHI Takahiro <takahiro.akashi@linaro.org> - 2017-09-08 05:20 +0200
    [PATCH 3/9] kexec_file: factor out crashdump elf header function from x86 AKASHI Takahiro <takahiro.akashi@linaro.org> - 2017-09-08 05:20 +0200
      Re: [PATCH 3/9] kexec_file: factor out crashdump elf header function  from x86 Dave Young <dyoung@redhat.com> - 2017-09-12 08:00 +0200
        Re: [PATCH 3/9] kexec_file: factor out crashdump elf header function  from x86 AKASHI Takahiro <takahiro.akashi@linaro.org> - 2017-09-13 02:50 +0200

#1728563 — [PATCH 0/9] kexec: add kexec_file_load() support

This is the second round of implementing kexec_file_load() support
on arm64.[1]
Most of the code is based on kexec-tools (along with some kernel code
from x86, which also came from kexec-tools).


This patch series enables us to
  * load the kernel, Image, with kexec_file_load system call, and
  * optionally verify its signature at load time for trusted boot.

To load the kernel via kexec_file_load system call, a small change
is also needed to kexec-tools. See [2]. This enables '-s' option.

As we discussed a long time ago, users may not be allowed to specify
device-tree file of the 2nd kernel explicitly with kexec-tools, therefore
re-using the blob of the first kernel.

Regarding a signing method, we conform with x86 (or rather Microsoft?)
style of signing since the binary can also be seen as in PE format
(assuming that CONFIG_EFI is enabled).

    Powerpc is also going to support extended-file-attribute-based
    verification[3] with vmlinux, but arm64 doesn't for now partly
    because we don't have TPM-based IMA at this moment.

Accordingly, we can use the existing command, sbsign, to sign the kernel.

    $ sbsign --key ${KEY} --cert ${CERT} Image

Please note that it is totally up to the system what key/certificate is
used for signing, but one of easy ways to *try* this feature is to turn on
CONFIG_MODULE_SIG so that we can reuse certs/signing_key.pem as a signing
key, KEY and CERT above, for kernel.
(This also enables CONFIG_CRYPTO_SHA1 by default.)


Some concerns(or future works):
* Even if the kernel is configured with CONFIG_RANDOMIZE_BASE, the 2nd
  kernel won't be placed at a randomized address. We will have to
  add some boot code similar to efi-stub to implement the feature.
* While big-endian kernel can support kernel signing, I'm not sure that
  Image can be recognized as in PE format because x86 standard only
  defines little-endian-based format.
* IMA(and file extended attribute)-based kexec
* vmlinux support

  [1] http://git.linaro.org/people/takahiro.akashi/linux-aarch64.git
	branch:arm64/kexec_file
  [2] http://git.linaro.org/people/takahiro.akashi/kexec-tools.git
	branch:arm64/kexec_file
  [3] http://lkml.iu.edu//hypermail/linux/kernel/1707.0/03669.html


Changes in v2 (Sep 8, 2017)
* move core-header-related functions from crash_core.c to kexec_file.c
* drop hash-check code from purgatory
* modify purgatory asm to remove arch_kexec_apply_relocations_add()
* drop older kernel support
* drop vmlinux support (at least, for this series)

Patch #1 to #4 are all preparatory patches on generic side.
Patch #5 is purgatory code.
Patch #6 to #8 are common for enabling kexec_file_load.
Patch #9 is for 'Image' support.


AKASHI Takahiro (9):
  include: pe.h: remove message[] from mz header definition
  resource: add walk_system_ram_res_rev()
  kexec_file: factor out crashdump elf header function from x86
  asm-generic: add kexec_file_load system call to unistd.h
  arm64: kexec_file: create purgatory
  arm64: kexec_file: load initrd, device-tree and purgatory segments
  arm64: kexec_file: set up for crash dump adding elf core header
  arm64: enable KEXEC_FILE config
  arm64: kexec_file: add Image format support

 arch/arm64/Kconfig                     |  29 +++
 arch/arm64/Makefile                    |   1 +
 arch/arm64/include/asm/kexec.h         |  24 ++
 arch/arm64/include/asm/kexec_file.h    |  69 ++++++
 arch/arm64/kernel/Makefile             |   4 +-
 arch/arm64/kernel/kexec_image.c        | 106 +++++++++
 arch/arm64/kernel/machine_kexec_file.c | 413 +++++++++++++++++++++++++++++++++
 arch/arm64/purgatory/Makefile          |  24 ++
 arch/arm64/purgatory/entry.S           |  55 +++++
 arch/x86/kernel/crash.c                | 324 --------------------------
 include/linux/ioport.h                 |   3 +
 include/linux/kexec.h                  |  19 ++
 include/linux/pe.h                     |   2 +-
 include/uapi/asm-generic/unistd.h      |   4 +-
 kernel/kexec_file.c                    | 329 ++++++++++++++++++++++++++
 kernel/resource.c                      |  59 +++++
 16 files changed, 1138 insertions(+), 327 deletions(-)
 create mode 100644 arch/arm64/include/asm/kexec_file.h
 create mode 100644 arch/arm64/kernel/kexec_image.c
 create mode 100644 arch/arm64/kernel/machine_kexec_file.c
 create mode 100644 arch/arm64/purgatory/Makefile
 create mode 100644 arch/arm64/purgatory/entry.S

-- 
2.14.1

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#1728564 — [PATCH 2/9] resource: add walk_system_ram_res_rev()

This function, being a variant of walk_system_ram_res() introduced in
commit 8c86e70acead ("resource: provide new functions to walk through
resources"), walks through a list of all the resources of System RAM
in reversed order, i.e., from higher to lower.

It will be used in kexec_file implementation on arm64.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
---
 include/linux/ioport.h |  3 +++
 kernel/resource.c      | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 6230064d7f95..9a212266299f 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -271,6 +271,9 @@ extern int
 walk_system_ram_res(u64 start, u64 end, void *arg,
 		    int (*func)(u64, u64, void *));
 extern int
+walk_system_ram_res_rev(u64 start, u64 end, void *arg,
+			int (*func)(u64, u64, void *));
+extern int
 walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, u64 end,
 		    void *arg, int (*func)(u64, u64, void *));
 
diff --git a/kernel/resource.c b/kernel/resource.c
index 9b5f04404152..572f2f91ce9c 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -23,6 +23,8 @@
 #include <linux/pfn.h>
 #include <linux/mm.h>
 #include <linux/resource_ext.h>
+#include <linux/string.h>
+#include <linux/vmalloc.h>
 #include <asm/io.h>
 
 
@@ -469,6 +471,63 @@ int walk_system_ram_res(u64 start, u64 end, void *arg,
 	return ret;
 }
 
+int walk_system_ram_res_rev(u64 start, u64 end, void *arg,
+				int (*func)(u64, u64, void *))
+{
+	struct resource res, *rams;
+	u64 orig_end;
+	int count, i;
+	int ret = -1;
+
+	count = 16; /* initial */
+
+	/* create a list */
+	rams = vmalloc(sizeof(struct resource) * count);
+	if (!rams)
+		return ret;
+
+	res.start = start;
+	res.end = end;
+	res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+	orig_end = res.end;
+	i = 0;
+	while ((res.start < res.end) &&
+		(!find_next_iomem_res(&res, IORES_DESC_NONE, true))) {
+		if (i >= count) {
+			/* re-alloc */
+			struct resource *rams_new;
+			int count_new;
+
+			count_new = count + 16;
+			rams_new = vmalloc(sizeof(struct resource) * count_new);
+			if (!rams_new)
+				goto out;
+
+			memcpy(rams_new, rams, count);
+			vfree(rams);
+			rams = rams_new;
+			count = count_new;
+		}
+
+		rams[i].start = res.start;
+		rams[i++].end = res.end;
+
+		res.start = res.end + 1;
+		res.end = orig_end;
+	}
+
+	/* go reverse */
+	for (i--; i >= 0; i--) {
+		ret = (*func)(rams[i].start, rams[i].end, arg);
+		if (ret)
+			break;
+	}
+
+out:
+	vfree(rams);
+	return ret;
+}
+
 #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
 
 /*
-- 
2.14.1

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#1728565 — [PATCH 6/9] arm64: kexec_file: load initrd, device-tree and purgatory segments

load_other_segments() sets up and adds all the memory segments necessary
other than kernel, including initrd, device-tree blob and purgatory.
Most of the code was borrowed from kexec-tools' counterpart.

In addition, arch_kexec_image_probe(), arch_kexec_image_load() and
arch_kexec_kernel_verify_sig() are added as stubs for supporting multiple
types of kernel image formats.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/kexec.h         |  19 +++
 arch/arm64/kernel/machine_kexec_file.c | 264 +++++++++++++++++++++++++++++++++
 2 files changed, 283 insertions(+)
 create mode 100644 arch/arm64/kernel/machine_kexec_file.c

diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
index e17f0529a882..d74dc49670ad 100644
--- a/arch/arm64/include/asm/kexec.h
+++ b/arch/arm64/include/asm/kexec.h
@@ -93,6 +93,25 @@ static inline void crash_prepare_suspend(void) {}
 static inline void crash_post_resume(void) {}
 #endif
 
+#ifdef CONFIG_KEXEC_FILE
+#define ARCH_HAS_KIMAGE_ARCH
+
+struct kimage_arch {
+	void *dtb_buf;
+};
+
+struct kimage;
+
+extern int setup_dtb(struct kimage *image,
+		unsigned long initrd_load_addr, unsigned long initrd_len,
+		char *cmdline, unsigned long cmdline_len,
+		char **dtb_buf, size_t *dtb_buf_len);
+extern int load_other_segments(struct kimage *image,
+		unsigned long kernel_load_addr,
+		char *initrd, unsigned long initrd_len,
+		char *cmdline, unsigned long cmdline_len);
+#endif
+
 #endif /* __ASSEMBLY__ */
 
 #endif
diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
new file mode 100644
index 000000000000..a6d2c006b4f7
--- /dev/null
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -0,0 +1,264 @@
+/*
+ * kexec_file for arm64
+ *
+ * Copyright (C) 2017 Linaro Limited
+ * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
+ *
+ * Most code is derived from arm64 port of kexec-tools
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) "kexec_file: " fmt
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <linux/libfdt.h>
+#include <linux/memblock.h>
+#include <linux/of_fdt.h>
+#include <asm/kexec_file.h>
+
+static int __dt_root_addr_cells;
+static int __dt_root_size_cells;
+
+static struct kexec_file_ops *kexec_file_loaders[0];
+
+int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
+				  unsigned long buf_len)
+{
+	struct kexec_file_ops *fops;
+	int i, ret;
+
+	for (i = 0; i < ARRAY_SIZE(kexec_file_loaders); i++) {
+		fops = kexec_file_loaders[i];
+		if (!fops || !fops->probe)
+			continue;
+
+		ret = fops->probe(buf, buf_len);
+		if (!ret) {
+			image->fops = fops;
+			return 0;
+		}
+	}
+
+	return -ENOEXEC;
+}
+
+void *arch_kexec_kernel_image_load(struct kimage *image)
+{
+	if (!image->fops || !image->fops->load)
+		return ERR_PTR(-ENOEXEC);
+
+	return image->fops->load(image, image->kernel_buf,
+				 image->kernel_buf_len, image->initrd_buf,
+				 image->initrd_buf_len, image->cmdline_buf,
+				 image->cmdline_buf_len);
+}
+
+int arch_kimage_file_post_load_cleanup(struct kimage *image)
+{
+	vfree(image->arch.dtb_buf);
+	image->arch.dtb_buf = NULL;
+
+	vfree(image->arch.elf_headers);
+	image->arch.elf_headers = NULL;
+	image->arch.elf_headers_sz = 0;
+
+	if (!image->fops || !image->fops->cleanup)
+		return 0;
+
+	return image->fops->cleanup(image->image_loader_data);
+}
+
+#ifdef CONFIG_KEXEC_VERIFY_SIG
+int arch_kexec_kernel_verify_sig(struct kimage *image, void *kernel,
+				 unsigned long kernel_len)
+{
+	if (!image->fops || !image->fops->verify_sig) {
+		pr_debug("kernel loader does not support signature verification.\n");
+		return -EKEYREJECTED;
+	}
+
+	return image->fops->verify_sig(kernel, kernel_len);
+}
+#endif
+
+int arch_kexec_walk_mem(struct kexec_buf *kbuf, int (*func)(u64, u64, void *))
+{
+	if (kbuf->image->type == KEXEC_TYPE_CRASH)
+		return walk_iomem_res_desc(crashk_res.desc,
+					IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
+					crashk_res.start, crashk_res.end,
+					kbuf, func);
+	else if (kbuf->top_down)
+		return walk_system_ram_res_rev(0, ULONG_MAX, kbuf, func);
+	else
+		return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
+}
+
+int setup_dtb(struct kimage *image,
+		unsigned long initrd_load_addr, unsigned long initrd_len,
+		char *cmdline, unsigned long cmdline_len,
+		char **dtb_buf, size_t *dtb_buf_len)
+{
+	char *buf = NULL;
+	size_t buf_size;
+	int nodeoffset;
+	u64 value;
+	int range_len;
+	int ret;
+
+	/* duplicate dt blob */
+	buf_size = fdt_totalsize(initial_boot_params);
+	range_len = (__dt_root_addr_cells + __dt_root_size_cells) * sizeof(u32);
+
+	if (initrd_load_addr)
+		buf_size += fdt_prop_len("initrd-start", sizeof(u64))
+				+ fdt_prop_len("initrd-end", sizeof(u64));
+
+	if (cmdline)
+		buf_size += fdt_prop_len("bootargs", cmdline_len + 1);
+
+	buf = vmalloc(buf_size);
+	if (!buf) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
+
+	ret = fdt_open_into(initial_boot_params, buf, buf_size);
+	if (ret)
+		goto out_err;
+
+	nodeoffset = fdt_path_offset(buf, "/chosen");
+	if (nodeoffset < 0)
+		goto out_err;
+
+	/* add bootargs */
+	if (cmdline) {
+		ret = fdt_setprop(buf, nodeoffset, "bootargs",
+						cmdline, cmdline_len + 1);
+		if (ret)
+			goto out_err;
+	}
+
+	/* add initrd-* */
+	if (initrd_load_addr) {
+		value = cpu_to_fdt64(initrd_load_addr);
+		ret = fdt_setprop(buf, nodeoffset, "initrd-start",
+				&value, sizeof(value));
+		if (ret)
+			goto out_err;
+
+		value = cpu_to_fdt64(initrd_load_addr + initrd_len);
+		ret = fdt_setprop(buf, nodeoffset, "initrd-end",
+				&value, sizeof(value));
+		if (ret)
+			goto out_err;
+	}
+
+	/* trim a buffer */
+	fdt_pack(buf);
+	*dtb_buf = buf;
+	*dtb_buf_len = fdt_totalsize(buf);
+
+	return 0;
+
+out_err:
+	vfree(buf);
+	return ret;
+}
+
+int load_other_segments(struct kimage *image, unsigned long kernel_load_addr,
+			char *initrd, unsigned long initrd_len,
+			char *cmdline, unsigned long cmdline_len)
+{
+	struct kexec_buf kbuf;
+	unsigned long initrd_load_addr = 0;
+	unsigned long purgatory_load_addr, dtb_load_addr;
+	char *dtb = NULL;
+	unsigned long dtb_len;
+	int ret = 0;
+
+	kbuf.image = image;
+	/* not allocate anything below the kernel */
+	kbuf.buf_min = kernel_load_addr;
+
+	/* Load initrd */
+	if (initrd) {
+		kbuf.buffer = initrd;
+		kbuf.bufsz = initrd_len;
+		kbuf.memsz = initrd_len;
+		kbuf.buf_align = PAGE_SIZE;
+		/* within 1GB-aligned window of up to 32GB in size */
+		kbuf.buf_max = round_down(kernel_load_addr, SZ_1G)
+						+ (unsigned long)SZ_1G * 31;
+		kbuf.top_down = 0;
+
+		ret = kexec_add_buffer(&kbuf);
+		if (ret)
+			goto out_err;
+		initrd_load_addr = kbuf.mem;
+
+		pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
+				initrd_load_addr, initrd_len, initrd_len);
+	}
+
+	/* Load dtb blob */
+	ret = setup_dtb(image, initrd_load_addr, initrd_len,
+				cmdline, cmdline_len, &dtb, &dtb_len);
+	if (ret) {
+		pr_err("Preparing for new dtb failed\n");
+		goto out_err;
+	}
+
+	kbuf.buffer = dtb;
+	kbuf.bufsz = dtb_len;
+	kbuf.memsz = dtb_len;
+	/* not across 2MB boundary */
+	kbuf.buf_align = SZ_2M;
+	kbuf.buf_max = ULONG_MAX;
+	kbuf.top_down = 1;
+
+	ret = kexec_add_buffer(&kbuf);
+	if (ret)
+		goto out_err;
+	dtb_load_addr = kbuf.mem;
+	image->arch.dtb_buf = dtb;
+
+	pr_debug("Loaded dtb at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
+			dtb_load_addr, dtb_len, dtb_len);
+
+	/* Load purgatory  */
+	ret = kexec_load_purgatory(image, kernel_load_addr, ULONG_MAX, 1,
+				   &purgatory_load_addr);
+	if (ret) {
+		pr_err("Loading purgatory failed\n");
+		goto out_err;
+	}
+
+	ret = kexec_purgatory_get_set_symbol(image, "kernel_entry",
+				&kernel_load_addr, sizeof(kernel_load_addr), 0);
+	if (ret) {
+		pr_err("Setting symbol (kernel_entry) failed.\n");
+		goto out_err;
+	}
+
+	ret = kexec_purgatory_get_set_symbol(image, "dtb_addr",
+				&dtb_load_addr, sizeof(dtb_load_addr), 0);
+	if (ret) {
+		pr_err("Setting symbol (dtb_addr) failed.\n");
+		goto out_err;
+	}
+
+	pr_debug("Loaded purgatory at 0x%lx\n", purgatory_load_addr);
+
+	return 0;
+
+out_err:
+	vfree(dtb);
+	image->arch.dtb_buf = NULL;
+	return ret;
+}
-- 
2.14.1

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#1730167 — Re: [PATCH 6/9] arm64: kexec_file: load initrd, device-tree and purgatory segments

Hi,

On 09/08/17 at 12:16pm, AKASHI Takahiro wrote:
> load_other_segments() sets up and adds all the memory segments necessary
> other than kernel, including initrd, device-tree blob and purgatory.
> Most of the code was borrowed from kexec-tools' counterpart.
> 
> In addition, arch_kexec_image_probe(), arch_kexec_image_load() and
> arch_kexec_kernel_verify_sig() are added as stubs for supporting multiple
> types of kernel image formats.
> 
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> ---
>  arch/arm64/include/asm/kexec.h         |  19 +++
>  arch/arm64/kernel/machine_kexec_file.c | 264 +++++++++++++++++++++++++++++++++
>  2 files changed, 283 insertions(+)
>  create mode 100644 arch/arm64/kernel/machine_kexec_file.c
> 
> diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
> index e17f0529a882..d74dc49670ad 100644
> --- a/arch/arm64/include/asm/kexec.h
> +++ b/arch/arm64/include/asm/kexec.h
> @@ -93,6 +93,25 @@ static inline void crash_prepare_suspend(void) {}
>  static inline void crash_post_resume(void) {}
>  #endif
>  
> +#ifdef CONFIG_KEXEC_FILE
> +#define ARCH_HAS_KIMAGE_ARCH
> +
> +struct kimage_arch {
> +	void *dtb_buf;
> +};
> +
> +struct kimage;
> +
> +extern int setup_dtb(struct kimage *image,
> +		unsigned long initrd_load_addr, unsigned long initrd_len,
> +		char *cmdline, unsigned long cmdline_len,
> +		char **dtb_buf, size_t *dtb_buf_len);
> +extern int load_other_segments(struct kimage *image,
> +		unsigned long kernel_load_addr,
> +		char *initrd, unsigned long initrd_len,
> +		char *cmdline, unsigned long cmdline_len);
> +#endif
> +
>  #endif /* __ASSEMBLY__ */
>  
>  #endif
> diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
> new file mode 100644
> index 000000000000..a6d2c006b4f7
> --- /dev/null
> +++ b/arch/arm64/kernel/machine_kexec_file.c
> @@ -0,0 +1,264 @@
> +/*
> + * kexec_file for arm64
> + *
> + * Copyright (C) 2017 Linaro Limited
> + * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
> + *
> + * Most code is derived from arm64 port of kexec-tools
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#define pr_fmt(fmt) "kexec_file: " fmt
> +
> +#include <linux/errno.h>
> +#include <linux/kernel.h>
> +#include <linux/kexec.h>
> +#include <linux/libfdt.h>
> +#include <linux/memblock.h>
> +#include <linux/of_fdt.h>
> +#include <asm/kexec_file.h>
> +
> +static int __dt_root_addr_cells;
> +static int __dt_root_size_cells;
> +
> +static struct kexec_file_ops *kexec_file_loaders[0];
> +
> +int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
> +				  unsigned long buf_len)
> +{
> +	struct kexec_file_ops *fops;
> +	int i, ret;
> +
> +	for (i = 0; i < ARRAY_SIZE(kexec_file_loaders); i++) {
> +		fops = kexec_file_loaders[i];
> +		if (!fops || !fops->probe)
> +			continue;
> +
> +		ret = fops->probe(buf, buf_len);
> +		if (!ret) {
> +			image->fops = fops;
> +			return 0;
> +		}
> +	}
> +
> +	return -ENOEXEC;
> +}
> +
> +void *arch_kexec_kernel_image_load(struct kimage *image)
> +{
> +	if (!image->fops || !image->fops->load)
> +		return ERR_PTR(-ENOEXEC);
> +
> +	return image->fops->load(image, image->kernel_buf,
> +				 image->kernel_buf_len, image->initrd_buf,
> +				 image->initrd_buf_len, image->cmdline_buf,
> +				 image->cmdline_buf_len);
> +}
> +
> +int arch_kimage_file_post_load_cleanup(struct kimage *image)
> +{
> +	vfree(image->arch.dtb_buf);
> +	image->arch.dtb_buf = NULL;
> +
> +	vfree(image->arch.elf_headers);
> +	image->arch.elf_headers = NULL;
> +	image->arch.elf_headers_sz = 0;
> +
> +	if (!image->fops || !image->fops->cleanup)
> +		return 0;
> +
> +	return image->fops->cleanup(image->image_loader_data);
> +}
> +
> +#ifdef CONFIG_KEXEC_VERIFY_SIG
> +int arch_kexec_kernel_verify_sig(struct kimage *image, void *kernel,
> +				 unsigned long kernel_len)
> +{
> +	if (!image->fops || !image->fops->verify_sig) {
> +		pr_debug("kernel loader does not support signature verification.\n");
> +		return -EKEYREJECTED;
> +	}
> +
> +	return image->fops->verify_sig(kernel, kernel_len);
> +}


arch_kexec_kernel_verify_sig now be duplicated so it can be put in the
general function in kexec_file.c

Also the probe and load function are also duplicated, they can be moved
to common code as well.

The x86 load function can be cleaned up with removing the vfree
callback.

---
 arch/x86/kernel/machine_kexec_64.c |    3 ---
 1 file changed, 3 deletions(-)

--- linux-x86.orig/arch/x86/kernel/machine_kexec_64.c
+++ linux-x86/arch/x86/kernel/machine_kexec_64.c
@@ -384,9 +384,6 @@ int arch_kexec_kernel_image_probe(struct
 
 void *arch_kexec_kernel_image_load(struct kimage *image)
 {
-	vfree(image->arch.elf_headers);
-	image->arch.elf_headers = NULL;
-
 	if (!image->fops || !image->fops->load)
 		return ERR_PTR(-ENOEXEC);
 

> +#endif
> +
> +int arch_kexec_walk_mem(struct kexec_buf *kbuf, int (*func)(u64, u64, void *))
> +{
> +	if (kbuf->image->type == KEXEC_TYPE_CRASH)
> +		return walk_iomem_res_desc(crashk_res.desc,
> +					IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
> +					crashk_res.start, crashk_res.end,
> +					kbuf, func);
> +	else if (kbuf->top_down)
> +		return walk_system_ram_res_rev(0, ULONG_MAX, kbuf, func);
> +	else
> +		return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
> +}
> +
> +int setup_dtb(struct kimage *image,
> +		unsigned long initrd_load_addr, unsigned long initrd_len,
> +		char *cmdline, unsigned long cmdline_len,
> +		char **dtb_buf, size_t *dtb_buf_len)
> +{
> +	char *buf = NULL;
> +	size_t buf_size;
> +	int nodeoffset;
> +	u64 value;
> +	int range_len;
> +	int ret;
> +
> +	/* duplicate dt blob */
> +	buf_size = fdt_totalsize(initial_boot_params);
> +	range_len = (__dt_root_addr_cells + __dt_root_size_cells) * sizeof(u32);
> +
> +	if (initrd_load_addr)
> +		buf_size += fdt_prop_len("initrd-start", sizeof(u64))
> +				+ fdt_prop_len("initrd-end", sizeof(u64));
> +
> +	if (cmdline)
> +		buf_size += fdt_prop_len("bootargs", cmdline_len + 1);
> +
> +	buf = vmalloc(buf_size);
> +	if (!buf) {
> +		ret = -ENOMEM;
> +		goto out_err;
> +	}
> +
> +	ret = fdt_open_into(initial_boot_params, buf, buf_size);
> +	if (ret)
> +		goto out_err;
> +
> +	nodeoffset = fdt_path_offset(buf, "/chosen");
> +	if (nodeoffset < 0)
> +		goto out_err;
> +
> +	/* add bootargs */
> +	if (cmdline) {
> +		ret = fdt_setprop(buf, nodeoffset, "bootargs",
> +						cmdline, cmdline_len + 1);
> +		if (ret)
> +			goto out_err;
> +	}
> +
> +	/* add initrd-* */
> +	if (initrd_load_addr) {
> +		value = cpu_to_fdt64(initrd_load_addr);
> +		ret = fdt_setprop(buf, nodeoffset, "initrd-start",
> +				&value, sizeof(value));
> +		if (ret)
> +			goto out_err;
> +
> +		value = cpu_to_fdt64(initrd_load_addr + initrd_len);
> +		ret = fdt_setprop(buf, nodeoffset, "initrd-end",
> +				&value, sizeof(value));
> +		if (ret)
> +			goto out_err;
> +	}
> +
> +	/* trim a buffer */
> +	fdt_pack(buf);
> +	*dtb_buf = buf;
> +	*dtb_buf_len = fdt_totalsize(buf);
> +
> +	return 0;
> +
> +out_err:
> +	vfree(buf);
> +	return ret;
> +}
> +
> +int load_other_segments(struct kimage *image, unsigned long kernel_load_addr,
> +			char *initrd, unsigned long initrd_len,
> +			char *cmdline, unsigned long cmdline_len)
> +{
> +	struct kexec_buf kbuf;
> +	unsigned long initrd_load_addr = 0;
> +	unsigned long purgatory_load_addr, dtb_load_addr;
> +	char *dtb = NULL;
> +	unsigned long dtb_len;
> +	int ret = 0;
> +
> +	kbuf.image = image;
> +	/* not allocate anything below the kernel */
> +	kbuf.buf_min = kernel_load_addr;
> +
> +	/* Load initrd */
> +	if (initrd) {
> +		kbuf.buffer = initrd;
> +		kbuf.bufsz = initrd_len;
> +		kbuf.memsz = initrd_len;
> +		kbuf.buf_align = PAGE_SIZE;
> +		/* within 1GB-aligned window of up to 32GB in size */
> +		kbuf.buf_max = round_down(kernel_load_addr, SZ_1G)
> +						+ (unsigned long)SZ_1G * 31;
> +		kbuf.top_down = 0;
> +
> +		ret = kexec_add_buffer(&kbuf);
> +		if (ret)
> +			goto out_err;
> +		initrd_load_addr = kbuf.mem;
> +
> +		pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
> +				initrd_load_addr, initrd_len, initrd_len);
> +	}
> +
> +	/* Load dtb blob */
> +	ret = setup_dtb(image, initrd_load_addr, initrd_len,
> +				cmdline, cmdline_len, &dtb, &dtb_len);
> +	if (ret) {
> +		pr_err("Preparing for new dtb failed\n");
> +		goto out_err;
> +	}
> +
> +	kbuf.buffer = dtb;
> +	kbuf.bufsz = dtb_len;
> +	kbuf.memsz = dtb_len;
> +	/* not across 2MB boundary */
> +	kbuf.buf_align = SZ_2M;
> +	kbuf.buf_max = ULONG_MAX;
> +	kbuf.top_down = 1;
> +
> +	ret = kexec_add_buffer(&kbuf);
> +	if (ret)
> +		goto out_err;
> +	dtb_load_addr = kbuf.mem;
> +	image->arch.dtb_buf = dtb;
> +
> +	pr_debug("Loaded dtb at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
> +			dtb_load_addr, dtb_len, dtb_len);
> +
> +	/* Load purgatory  */
> +	ret = kexec_load_purgatory(image, kernel_load_addr, ULONG_MAX, 1,
> +				   &purgatory_load_addr);
> +	if (ret) {
> +		pr_err("Loading purgatory failed\n");
> +		goto out_err;
> +	}
> +
> +	ret = kexec_purgatory_get_set_symbol(image, "kernel_entry",
> +				&kernel_load_addr, sizeof(kernel_load_addr), 0);
> +	if (ret) {
> +		pr_err("Setting symbol (kernel_entry) failed.\n");
> +		goto out_err;
> +	}
> +
> +	ret = kexec_purgatory_get_set_symbol(image, "dtb_addr",
> +				&dtb_load_addr, sizeof(dtb_load_addr), 0);
> +	if (ret) {
> +		pr_err("Setting symbol (dtb_addr) failed.\n");
> +		goto out_err;
> +	}
> +
> +	pr_debug("Loaded purgatory at 0x%lx\n", purgatory_load_addr);
> +
> +	return 0;
> +
> +out_err:
> +	vfree(dtb);
> +	image->arch.dtb_buf = NULL;
> +	return ret;
> +}
> -- 
> 2.14.1
> 
> 
> _______________________________________________
> kexec mailing list
> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec

Thanks
Dave

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#1730204 — Re: [PATCH 6/9] arm64: kexec_file: load initrd, device-tree and purgatory segments

> > +int arch_kimage_file_post_load_cleanup(struct kimage *image)
> > +{
> > +	vfree(image->arch.dtb_buf);
> > +	image->arch.dtb_buf = NULL;
> > +
> > +	vfree(image->arch.elf_headers);
> > +	image->arch.elf_headers = NULL;
> > +	image->arch.elf_headers_sz = 0;
> > +
> > +	if (!image->fops || !image->fops->cleanup)
> > +		return 0;
> > +
> > +	return image->fops->cleanup(image->image_loader_data);
> > +}
> > +
> > +#ifdef CONFIG_KEXEC_VERIFY_SIG
> > +int arch_kexec_kernel_verify_sig(struct kimage *image, void *kernel,
> > +				 unsigned long kernel_len)
> > +{
> > +	if (!image->fops || !image->fops->verify_sig) {
> > +		pr_debug("kernel loader does not support signature verification.\n");
> > +		return -EKEYREJECTED;
> > +	}
> > +
> > +	return image->fops->verify_sig(kernel, kernel_len);
> > +}
> 
> 
> arch_kexec_kernel_verify_sig now be duplicated so it can be put in the
> general function in kexec_file.c
> 
> Also the probe and load function are also duplicated, they can be moved
> to common code as well.
> 
> The x86 load function can be cleaned up with removing the vfree
> callback.
> 
> ---
>  arch/x86/kernel/machine_kexec_64.c |    3 ---
>  1 file changed, 3 deletions(-)
> 
> --- linux-x86.orig/arch/x86/kernel/machine_kexec_64.c
> +++ linux-x86/arch/x86/kernel/machine_kexec_64.c
> @@ -384,9 +384,6 @@ int arch_kexec_kernel_image_probe(struct
>  
>  void *arch_kexec_kernel_image_load(struct kimage *image)
>  {
> -	vfree(image->arch.elf_headers);
> -	image->arch.elf_headers = NULL;
> -

Hmm, should move above to arch_kimage_file_post_load_cleanup instead.. 

>  	if (!image->fops || !image->fops->load)
>  		return ERR_PTR(-ENOEXEC);
>  
> 


Thanks
Dave

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#1730654 — Re: [PATCH 6/9] arm64: kexec_file: load initrd, device-tree and purgatory segments

On Mon, Sep 11, 2017 at 02:47:54PM +0800, Dave Young wrote:
> Hi,
> 
> On 09/08/17 at 12:16pm, AKASHI Takahiro wrote:
> > load_other_segments() sets up and adds all the memory segments necessary
> > other than kernel, including initrd, device-tree blob and purgatory.
> > Most of the code was borrowed from kexec-tools' counterpart.
> > 
> > In addition, arch_kexec_image_probe(), arch_kexec_image_load() and
> > arch_kexec_kernel_verify_sig() are added as stubs for supporting multiple
> > types of kernel image formats.
> > 
> > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> > Cc: Catalin Marinas <catalin.marinas@arm.com>
> > Cc: Will Deacon <will.deacon@arm.com>
> > ---
> >  arch/arm64/include/asm/kexec.h         |  19 +++
> >  arch/arm64/kernel/machine_kexec_file.c | 264 +++++++++++++++++++++++++++++++++
> >  2 files changed, 283 insertions(+)
> >  create mode 100644 arch/arm64/kernel/machine_kexec_file.c
> > 
> > diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
> > index e17f0529a882..d74dc49670ad 100644
> > --- a/arch/arm64/include/asm/kexec.h
> > +++ b/arch/arm64/include/asm/kexec.h
> > @@ -93,6 +93,25 @@ static inline void crash_prepare_suspend(void) {}
> >  static inline void crash_post_resume(void) {}
> >  #endif
> >  
> > +#ifdef CONFIG_KEXEC_FILE
> > +#define ARCH_HAS_KIMAGE_ARCH
> > +
> > +struct kimage_arch {
> > +	void *dtb_buf;
> > +};
> > +
> > +struct kimage;
> > +
> > +extern int setup_dtb(struct kimage *image,
> > +		unsigned long initrd_load_addr, unsigned long initrd_len,
> > +		char *cmdline, unsigned long cmdline_len,
> > +		char **dtb_buf, size_t *dtb_buf_len);
> > +extern int load_other_segments(struct kimage *image,
> > +		unsigned long kernel_load_addr,
> > +		char *initrd, unsigned long initrd_len,
> > +		char *cmdline, unsigned long cmdline_len);
> > +#endif
> > +
> >  #endif /* __ASSEMBLY__ */
> >  
> >  #endif
> > diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
> > new file mode 100644
> > index 000000000000..a6d2c006b4f7
> > --- /dev/null
> > +++ b/arch/arm64/kernel/machine_kexec_file.c
> > @@ -0,0 +1,264 @@
> > +/*
> > + * kexec_file for arm64
> > + *
> > + * Copyright (C) 2017 Linaro Limited
> > + * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
> > + *
> > + * Most code is derived from arm64 port of kexec-tools
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License version 2 as
> > + * published by the Free Software Foundation.
> > + */
> > +
> > +#define pr_fmt(fmt) "kexec_file: " fmt
> > +
> > +#include <linux/errno.h>
> > +#include <linux/kernel.h>
> > +#include <linux/kexec.h>
> > +#include <linux/libfdt.h>
> > +#include <linux/memblock.h>
> > +#include <linux/of_fdt.h>
> > +#include <asm/kexec_file.h>
> > +
> > +static int __dt_root_addr_cells;
> > +static int __dt_root_size_cells;
> > +
> > +static struct kexec_file_ops *kexec_file_loaders[0];
> > +
> > +int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
> > +				  unsigned long buf_len)
> > +{
> > +	struct kexec_file_ops *fops;
> > +	int i, ret;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(kexec_file_loaders); i++) {
> > +		fops = kexec_file_loaders[i];
> > +		if (!fops || !fops->probe)
> > +			continue;
> > +
> > +		ret = fops->probe(buf, buf_len);
> > +		if (!ret) {
> > +			image->fops = fops;
> > +			return 0;
> > +		}
> > +	}
> > +
> > +	return -ENOEXEC;
> > +}
> > +
> > +void *arch_kexec_kernel_image_load(struct kimage *image)
> > +{
> > +	if (!image->fops || !image->fops->load)
> > +		return ERR_PTR(-ENOEXEC);
> > +
> > +	return image->fops->load(image, image->kernel_buf,
> > +				 image->kernel_buf_len, image->initrd_buf,
> > +				 image->initrd_buf_len, image->cmdline_buf,
> > +				 image->cmdline_buf_len);
> > +}
> > +
> > +int arch_kimage_file_post_load_cleanup(struct kimage *image)
> > +{
> > +	vfree(image->arch.dtb_buf);
> > +	image->arch.dtb_buf = NULL;
> > +
> > +	vfree(image->arch.elf_headers);
> > +	image->arch.elf_headers = NULL;
> > +	image->arch.elf_headers_sz = 0;
> > +
> > +	if (!image->fops || !image->fops->cleanup)
> > +		return 0;
> > +
> > +	return image->fops->cleanup(image->image_loader_data);
> > +}
> > +
> > +#ifdef CONFIG_KEXEC_VERIFY_SIG
> > +int arch_kexec_kernel_verify_sig(struct kimage *image, void *kernel,
> > +				 unsigned long kernel_len)
> > +{
> > +	if (!image->fops || !image->fops->verify_sig) {
> > +		pr_debug("kernel loader does not support signature verification.\n");
> > +		return -EKEYREJECTED;
> > +	}
> > +
> > +	return image->fops->verify_sig(kernel, kernel_len);
> > +}
> 
> 
> arch_kexec_kernel_verify_sig now be duplicated so it can be put in the
> general function in kexec_file.c
> 
> Also the probe and load function are also duplicated, they can be moved
> to common code as well.

Okay!

> The x86 load function can be cleaned up with removing the vfree
> callback.

Sure

Thanks,
-Takahiro AKASHI

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#1728566 — [PATCH 7/9] arm64: kexec_file: set up for crash dump adding elf core header

load_crashdump_segments() creates and loads a memory segment of elf core
header for crash dump.

"linux,usable-memory-range" and "linux,elfcorehdr" will add to the 2nd
kernel's device-tree blob. The logic of this cod is also from kexec-tools.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/kexec.h         |   5 ++
 arch/arm64/kernel/machine_kexec_file.c | 145 +++++++++++++++++++++++++++++++++
 2 files changed, 150 insertions(+)

diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
index d74dc49670ad..66537de588fa 100644
--- a/arch/arm64/include/asm/kexec.h
+++ b/arch/arm64/include/asm/kexec.h
@@ -98,6 +98,10 @@ static inline void crash_post_resume(void) {}
 
 struct kimage_arch {
 	void *dtb_buf;
+	/* Core ELF header buffer */
+	void *elf_headers;
+	unsigned long elf_headers_sz;
+	unsigned long elf_load_addr;
 };
 
 struct kimage;
@@ -110,6 +114,7 @@ extern int load_other_segments(struct kimage *image,
 		unsigned long kernel_load_addr,
 		char *initrd, unsigned long initrd_len,
 		char *cmdline, unsigned long cmdline_len);
+extern int load_crashdump_segments(struct kimage *image);
 #endif
 
 #endif /* __ASSEMBLY__ */
diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
index a6d2c006b4f7..62627f5440ff 100644
--- a/arch/arm64/kernel/machine_kexec_file.c
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -99,6 +99,77 @@ int arch_kexec_walk_mem(struct kexec_buf *kbuf, int (*func)(u64, u64, void *))
 		return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
 }
 
+static int __init arch_kexec_file_init(void)
+{
+	/* Those values are used later on loading the kernel */
+	__dt_root_addr_cells = dt_root_addr_cells;
+	__dt_root_size_cells = dt_root_size_cells;
+
+	return 0;
+}
+late_initcall(arch_kexec_file_init);
+
+#define FDT_ALIGN(x, a)	(((x) + (a) - 1) & ~((a) - 1))
+#define FDT_TAGALIGN(x)	(FDT_ALIGN((x), FDT_TAGSIZE))
+
+static int fdt_prop_len(const char *prop_name, int len)
+{
+	return (strlen(prop_name) + 1) +
+		sizeof(struct fdt_property) +
+		FDT_TAGALIGN(len);
+}
+
+static bool cells_size_fitted(unsigned long base, unsigned long size)
+{
+	/* if *_cells >= 2, cells can hold 64-bit values anyway */
+	if ((__dt_root_addr_cells == 1) && (base >= (1ULL << 32)))
+		return false;
+
+	if ((__dt_root_size_cells == 1) && (size >= (1ULL << 32)))
+		return false;
+
+	return true;
+}
+
+static void fill_property(void *buf, u64 val64, int cells)
+{
+	u32 val32;
+	int i;
+
+	if (cells == 1) {
+		val32 = cpu_to_fdt32((u32)val64);
+		memcpy(buf, &val32, sizeof(val32));
+	} else {
+		for (i = 0; i < (cells * sizeof(u32) - sizeof(u64)); i++)
+			*(char *)buf++ = 0;
+
+		val64 = cpu_to_fdt64(val64);
+		memcpy(buf, &val64, sizeof(val64));
+	}
+}
+
+static int fdt_setprop_range(void *fdt, int nodeoffset, const char *name,
+				unsigned long addr, unsigned long size)
+{
+	u64 range[2];
+	void *prop;
+	size_t buf_size;
+	int result;
+
+	prop = range;
+	buf_size = (__dt_root_addr_cells + __dt_root_size_cells) * sizeof(u32);
+
+	fill_property(prop, addr, __dt_root_addr_cells);
+	prop += __dt_root_addr_cells * sizeof(u32);
+
+	fill_property(prop, size, __dt_root_size_cells);
+	prop += __dt_root_size_cells * sizeof(u32);
+
+	result = fdt_setprop(fdt, nodeoffset, name, range, buf_size);
+
+	return result;
+}
+
 int setup_dtb(struct kimage *image,
 		unsigned long initrd_load_addr, unsigned long initrd_len,
 		char *cmdline, unsigned long cmdline_len,
@@ -111,10 +182,26 @@ int setup_dtb(struct kimage *image,
 	int range_len;
 	int ret;
 
+	/* check ranges against root's #address-cells and #size-cells */
+	if (image->type == KEXEC_TYPE_CRASH &&
+		(!cells_size_fitted(image->arch.elf_load_addr,
+				image->arch.elf_headers_sz) ||
+		 !cells_size_fitted(crashk_res.start,
+				crashk_res.end - crashk_res.start + 1))) {
+		pr_err("Crash memory region doesn't fit into DT's root cell sizes.\n");
+		ret = -EINVAL;
+		goto out_err;
+	}
+
 	/* duplicate dt blob */
 	buf_size = fdt_totalsize(initial_boot_params);
 	range_len = (__dt_root_addr_cells + __dt_root_size_cells) * sizeof(u32);
 
+	if (image->type == KEXEC_TYPE_CRASH)
+		buf_size += fdt_prop_len("linux,elfcorehdr", range_len)
+				+ fdt_prop_len("linux,usable-memory-range",
+								range_len);
+
 	if (initrd_load_addr)
 		buf_size += fdt_prop_len("initrd-start", sizeof(u64))
 				+ fdt_prop_len("initrd-end", sizeof(u64));
@@ -136,6 +223,23 @@ int setup_dtb(struct kimage *image,
 	if (nodeoffset < 0)
 		goto out_err;
 
+	if (image->type == KEXEC_TYPE_CRASH) {
+		/* add linux,elfcorehdr */
+		ret = fdt_setprop_range(buf, nodeoffset, "linux,elfcorehdr",
+				image->arch.elf_load_addr,
+				image->arch.elf_headers_sz);
+		if (ret)
+			goto out_err;
+
+		/* add linux,usable-memory-range */
+		ret = fdt_setprop_range(buf, nodeoffset,
+				"linux,usable-memory-range",
+				crashk_res.start,
+				crashk_res.end - crashk_res.start + 1);
+		if (ret)
+			goto out_err;
+	}
+
 	/* add bootargs */
 	if (cmdline) {
 		ret = fdt_setprop(buf, nodeoffset, "bootargs",
@@ -262,3 +366,44 @@ int load_other_segments(struct kimage *image, unsigned long kernel_load_addr,
 	image->arch.dtb_buf = NULL;
 	return ret;
 }
+
+int load_crashdump_segments(struct kimage *image)
+{
+	void *elf_addr;
+	unsigned long elf_sz;
+	struct kexec_buf kbuf;
+	int ret;
+
+	if (image->type != KEXEC_TYPE_CRASH)
+		return 0;
+
+	/* Prepare elf headers and add a segment */
+	ret = prepare_elf_headers(image, &elf_addr, &elf_sz);
+	if (ret) {
+		pr_err("Preparing elf core header failed\n");
+		return ret;
+	}
+
+	kbuf.image = image;
+	kbuf.buffer = elf_addr;
+	kbuf.bufsz = elf_sz;
+	kbuf.memsz = elf_sz;
+	kbuf.buf_align = PAGE_SIZE;
+	kbuf.buf_min = crashk_res.start;
+	kbuf.buf_max = crashk_res.end + 1;
+	kbuf.top_down = 1;
+
+	ret = kexec_add_buffer(&kbuf);
+	if (ret) {
+		vfree(elf_addr);
+		return ret;
+	}
+	image->arch.elf_headers = elf_addr;
+	image->arch.elf_headers_sz = elf_sz;
+	image->arch.elf_load_addr = kbuf.mem;
+
+	pr_debug("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
+			 image->arch.elf_load_addr, elf_sz, elf_sz);
+
+	return ret;
+}
-- 
2.14.1

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#1728568 — [PATCH 1/9] include: pe.h: remove message[] from mz header definition

message[] field won't be part of the definition of mz header.

This change is crucial for enabling kexec_file_load on arm64 because
arm64's "Image" binary, as in PE format, doesn't have any data for it and
accordingly the following check in pefile_parse_binary() will fail:

	chkaddr(cursor, mz->peaddr, sizeof(*pe));

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David S. Miller <davem@davemloft.net>
---
 include/linux/pe.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/pe.h b/include/linux/pe.h
index 143ce75be5f0..3482b18a48b5 100644
--- a/include/linux/pe.h
+++ b/include/linux/pe.h
@@ -166,7 +166,7 @@ struct mz_hdr {
 	uint16_t oem_info;	/* oem specific */
 	uint16_t reserved1[10];	/* reserved */
 	uint32_t peaddr;	/* address of pe header */
-	char     message[64];	/* message to print */
+	char     message[];	/* message to print */
 };
 
 struct mz_reloc {
-- 
2.14.1

[toc] | [prev] | [next] | [standalone]

#1728570 — [PATCH 3/9] kexec_file: factor out crashdump elf header function from x86

prepare_elf_headers() can also be useful for other architectures,
including arm64. So let it factored out.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
---
 arch/x86/kernel/crash.c | 324 -----------------------------------------------
 include/linux/kexec.h   |  19 +++
 kernel/kexec_file.c     | 329 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 348 insertions(+), 324 deletions(-)

diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 44404e2307bb..3c6b880f6dbf 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -21,7 +21,6 @@
 #include <linux/elf.h>
 #include <linux/elfcore.h>
 #include <linux/export.h>
-#include <linux/slab.h>
 #include <linux/vmalloc.h>
 
 #include <asm/processor.h>
@@ -41,34 +40,6 @@
 /* Alignment required for elf header segment */
 #define ELF_CORE_HEADER_ALIGN   4096
 
-/* This primarily represents number of split ranges due to exclusion */
-#define CRASH_MAX_RANGES	16
-
-struct crash_mem_range {
-	u64 start, end;
-};
-
-struct crash_mem {
-	unsigned int nr_ranges;
-	struct crash_mem_range ranges[CRASH_MAX_RANGES];
-};
-
-/* Misc data about ram ranges needed to prepare elf headers */
-struct crash_elf_data {
-	struct kimage *image;
-	/*
-	 * Total number of ram ranges we have after various adjustments for
-	 * crash reserved region, etc.
-	 */
-	unsigned int max_nr_ranges;
-
-	/* Pointer to elf header */
-	void *ehdr;
-	/* Pointer to next phdr */
-	void *bufp;
-	struct crash_mem mem;
-};
-
 /* Used while preparing memory map entries for second kernel */
 struct crash_memmap_data {
 	struct boot_params *params;
@@ -209,301 +180,6 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
 }
 
 #ifdef CONFIG_KEXEC_FILE
-static int get_nr_ram_ranges_callback(u64 start, u64 end, void *arg)
-{
-	unsigned int *nr_ranges = arg;
-
-	(*nr_ranges)++;
-	return 0;
-}
-
-
-/* Gather all the required information to prepare elf headers for ram regions */
-static void fill_up_crash_elf_data(struct crash_elf_data *ced,
-				   struct kimage *image)
-{
-	unsigned int nr_ranges = 0;
-
-	ced->image = image;
-
-	walk_system_ram_res(0, -1, &nr_ranges,
-				get_nr_ram_ranges_callback);
-
-	ced->max_nr_ranges = nr_ranges;
-
-	/* Exclusion of crash region could split memory ranges */
-	ced->max_nr_ranges++;
-
-	/* If crashk_low_res is not 0, another range split possible */
-	if (crashk_low_res.end)
-		ced->max_nr_ranges++;
-}
-
-static int exclude_mem_range(struct crash_mem *mem,
-		unsigned long long mstart, unsigned long long mend)
-{
-	int i, j;
-	unsigned long long start, end;
-	struct crash_mem_range temp_range = {0, 0};
-
-	for (i = 0; i < mem->nr_ranges; i++) {
-		start = mem->ranges[i].start;
-		end = mem->ranges[i].end;
-
-		if (mstart > end || mend < start)
-			continue;
-
-		/* Truncate any area outside of range */
-		if (mstart < start)
-			mstart = start;
-		if (mend > end)
-			mend = end;
-
-		/* Found completely overlapping range */
-		if (mstart == start && mend == end) {
-			mem->ranges[i].start = 0;
-			mem->ranges[i].end = 0;
-			if (i < mem->nr_ranges - 1) {
-				/* Shift rest of the ranges to left */
-				for (j = i; j < mem->nr_ranges - 1; j++) {
-					mem->ranges[j].start =
-						mem->ranges[j+1].start;
-					mem->ranges[j].end =
-							mem->ranges[j+1].end;
-				}
-			}
-			mem->nr_ranges--;
-			return 0;
-		}
-
-		if (mstart > start && mend < end) {
-			/* Split original range */
-			mem->ranges[i].end = mstart - 1;
-			temp_range.start = mend + 1;
-			temp_range.end = end;
-		} else if (mstart != start)
-			mem->ranges[i].end = mstart - 1;
-		else
-			mem->ranges[i].start = mend + 1;
-		break;
-	}
-
-	/* If a split happend, add the split to array */
-	if (!temp_range.end)
-		return 0;
-
-	/* Split happened */
-	if (i == CRASH_MAX_RANGES - 1) {
-		pr_err("Too many crash ranges after split\n");
-		return -ENOMEM;
-	}
-
-	/* Location where new range should go */
-	j = i + 1;
-	if (j < mem->nr_ranges) {
-		/* Move over all ranges one slot towards the end */
-		for (i = mem->nr_ranges - 1; i >= j; i--)
-			mem->ranges[i + 1] = mem->ranges[i];
-	}
-
-	mem->ranges[j].start = temp_range.start;
-	mem->ranges[j].end = temp_range.end;
-	mem->nr_ranges++;
-	return 0;
-}
-
-/*
- * Look for any unwanted ranges between mstart, mend and remove them. This
- * might lead to split and split ranges are put in ced->mem.ranges[] array
- */
-static int elf_header_exclude_ranges(struct crash_elf_data *ced,
-		unsigned long long mstart, unsigned long long mend)
-{
-	struct crash_mem *cmem = &ced->mem;
-	int ret = 0;
-
-	memset(cmem->ranges, 0, sizeof(cmem->ranges));
-
-	cmem->ranges[0].start = mstart;
-	cmem->ranges[0].end = mend;
-	cmem->nr_ranges = 1;
-
-	/* Exclude crashkernel region */
-	ret = exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
-	if (ret)
-		return ret;
-
-	if (crashk_low_res.end) {
-		ret = exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
-		if (ret)
-			return ret;
-	}
-
-	return ret;
-}
-
-static int prepare_elf64_ram_headers_callback(u64 start, u64 end, void *arg)
-{
-	struct crash_elf_data *ced = arg;
-	Elf64_Ehdr *ehdr;
-	Elf64_Phdr *phdr;
-	unsigned long mstart, mend;
-	struct kimage *image = ced->image;
-	struct crash_mem *cmem;
-	int ret, i;
-
-	ehdr = ced->ehdr;
-
-	/* Exclude unwanted mem ranges */
-	ret = elf_header_exclude_ranges(ced, start, end);
-	if (ret)
-		return ret;
-
-	/* Go through all the ranges in ced->mem.ranges[] and prepare phdr */
-	cmem = &ced->mem;
-
-	for (i = 0; i < cmem->nr_ranges; i++) {
-		mstart = cmem->ranges[i].start;
-		mend = cmem->ranges[i].end;
-
-		phdr = ced->bufp;
-		ced->bufp += sizeof(Elf64_Phdr);
-
-		phdr->p_type = PT_LOAD;
-		phdr->p_flags = PF_R|PF_W|PF_X;
-		phdr->p_offset  = mstart;
-
-		/*
-		 * If a range matches backup region, adjust offset to backup
-		 * segment.
-		 */
-		if (mstart == image->arch.backup_src_start &&
-		    (mend - mstart + 1) == image->arch.backup_src_sz)
-			phdr->p_offset = image->arch.backup_load_addr;
-
-		phdr->p_paddr = mstart;
-		phdr->p_vaddr = (unsigned long long) __va(mstart);
-		phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
-		phdr->p_align = 0;
-		ehdr->e_phnum++;
-		pr_debug("Crash PT_LOAD elf header. phdr=%p vaddr=0x%llx, paddr=0x%llx, sz=0x%llx e_phnum=%d p_offset=0x%llx\n",
-			phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz,
-			ehdr->e_phnum, phdr->p_offset);
-	}
-
-	return ret;
-}
-
-static int prepare_elf64_headers(struct crash_elf_data *ced,
-		void **addr, unsigned long *sz)
-{
-	Elf64_Ehdr *ehdr;
-	Elf64_Phdr *phdr;
-	unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz;
-	unsigned char *buf, *bufp;
-	unsigned int cpu;
-	unsigned long long notes_addr;
-	int ret;
-
-	/* extra phdr for vmcoreinfo elf note */
-	nr_phdr = nr_cpus + 1;
-	nr_phdr += ced->max_nr_ranges;
-
-	/*
-	 * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
-	 * area on x86_64 (ffffffff80000000 - ffffffffa0000000).
-	 * I think this is required by tools like gdb. So same physical
-	 * memory will be mapped in two elf headers. One will contain kernel
-	 * text virtual addresses and other will have __va(physical) addresses.
-	 */
-
-	nr_phdr++;
-	elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr);
-	elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN);
-
-	buf = vzalloc(elf_sz);
-	if (!buf)
-		return -ENOMEM;
-
-	bufp = buf;
-	ehdr = (Elf64_Ehdr *)bufp;
-	bufp += sizeof(Elf64_Ehdr);
-	memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
-	ehdr->e_ident[EI_CLASS] = ELFCLASS64;
-	ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
-	ehdr->e_ident[EI_VERSION] = EV_CURRENT;
-	ehdr->e_ident[EI_OSABI] = ELF_OSABI;
-	memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
-	ehdr->e_type = ET_CORE;
-	ehdr->e_machine = ELF_ARCH;
-	ehdr->e_version = EV_CURRENT;
-	ehdr->e_phoff = sizeof(Elf64_Ehdr);
-	ehdr->e_ehsize = sizeof(Elf64_Ehdr);
-	ehdr->e_phentsize = sizeof(Elf64_Phdr);
-
-	/* Prepare one phdr of type PT_NOTE for each present cpu */
-	for_each_present_cpu(cpu) {
-		phdr = (Elf64_Phdr *)bufp;
-		bufp += sizeof(Elf64_Phdr);
-		phdr->p_type = PT_NOTE;
-		notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
-		phdr->p_offset = phdr->p_paddr = notes_addr;
-		phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t);
-		(ehdr->e_phnum)++;
-	}
-
-	/* Prepare one PT_NOTE header for vmcoreinfo */
-	phdr = (Elf64_Phdr *)bufp;
-	bufp += sizeof(Elf64_Phdr);
-	phdr->p_type = PT_NOTE;
-	phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note();
-	phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
-	(ehdr->e_phnum)++;
-
-#ifdef CONFIG_X86_64
-	/* Prepare PT_LOAD type program header for kernel text region */
-	phdr = (Elf64_Phdr *)bufp;
-	bufp += sizeof(Elf64_Phdr);
-	phdr->p_type = PT_LOAD;
-	phdr->p_flags = PF_R|PF_W|PF_X;
-	phdr->p_vaddr = (Elf64_Addr)_text;
-	phdr->p_filesz = phdr->p_memsz = _end - _text;
-	phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
-	(ehdr->e_phnum)++;
-#endif
-
-	/* Prepare PT_LOAD headers for system ram chunks. */
-	ced->ehdr = ehdr;
-	ced->bufp = bufp;
-	ret = walk_system_ram_res(0, -1, ced,
-			prepare_elf64_ram_headers_callback);
-	if (ret < 0)
-		return ret;
-
-	*addr = buf;
-	*sz = elf_sz;
-	return 0;
-}
-
-/* Prepare elf headers. Return addr and size */
-static int prepare_elf_headers(struct kimage *image, void **addr,
-					unsigned long *sz)
-{
-	struct crash_elf_data *ced;
-	int ret;
-
-	ced = kzalloc(sizeof(*ced), GFP_KERNEL);
-	if (!ced)
-		return -ENOMEM;
-
-	fill_up_crash_elf_data(ced, image);
-
-	/* By default prepare 64bit headers */
-	ret =  prepare_elf64_headers(ced, addr, sz);
-	kfree(ced);
-	return ret;
-}
-
 static int add_e820_entry(struct boot_params *params, struct e820_entry *entry)
 {
 	unsigned int nr_e820_entries;
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index dd056fab9e35..65897af3125c 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -162,6 +162,25 @@ int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
 			       int (*func)(u64, u64, void *));
 extern int kexec_add_buffer(struct kexec_buf *kbuf);
 int kexec_locate_mem_hole(struct kexec_buf *kbuf);
+#ifdef CONFIG_CRASH_CORE
+extern int prepare_elf_headers(struct kimage *image, void **addr,
+				unsigned long *sz);
+
+/* This primarily represents number of split ranges due to exclusion */
+#define CRASH_MAX_RANGES        16
+
+struct crash_mem_range {
+	u64 start, end;
+};
+
+struct crash_mem {
+	unsigned int nr_ranges;
+	struct crash_mem_range ranges[CRASH_MAX_RANGES];
+};
+
+extern int exclude_mem_range(struct crash_mem *mem,
+		unsigned long long mstart, unsigned long long mend);
+#endif /* CONFIG_CRASH_CORE */
 #endif /* CONFIG_KEXEC_FILE */
 
 struct kimage {
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 9f48f4412297..20565eae6bd5 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -22,6 +22,11 @@
 #include <linux/ima.h>
 #include <crypto/hash.h>
 #include <crypto/sha.h>
+#include <linux/elf.h>
+#include <linux/elfcore.h>
+#include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <linux/slab.h>
 #include <linux/syscalls.h>
 #include <linux/vmalloc.h>
 #include "kexec_internal.h"
@@ -1021,3 +1026,327 @@ int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
 
 	return 0;
 }
+
+#ifdef CONFIG_CRASH_CORE
+/* Alignment required for elf header segment */
+#define ELF_CORE_HEADER_ALIGN   4096
+
+/* Misc data about ram ranges needed to prepare elf headers */
+struct crash_elf_data {
+	struct kimage *image;
+	/*
+	 * Total number of ram ranges we have after various adjustments for
+	 * crash reserved region, etc.
+	 */
+	unsigned int max_nr_ranges;
+
+	/* Pointer to elf header */
+	void *ehdr;
+	/* Pointer to next phdr */
+	void *bufp;
+	struct crash_mem mem;
+};
+
+static int get_nr_ram_ranges_callback(u64 start, u64 end, void *arg)
+{
+	unsigned int *nr_ranges = arg;
+
+	(*nr_ranges)++;
+	return 0;
+}
+
+
+/* Gather all the required information to prepare elf headers for ram regions */
+static void fill_up_crash_elf_data(struct crash_elf_data *ced,
+				   struct kimage *image)
+{
+	unsigned int nr_ranges = 0;
+
+	ced->image = image;
+
+	walk_system_ram_res(0, -1, &nr_ranges,
+				get_nr_ram_ranges_callback);
+
+	ced->max_nr_ranges = nr_ranges;
+
+	/* Exclusion of crash region could split memory ranges */
+	ced->max_nr_ranges++;
+
+#ifdef CONFIG_X86_64
+	/* If crashk_low_res is not 0, another range split possible */
+	if (crashk_low_res.end)
+		ced->max_nr_ranges++;
+#endif
+}
+
+int exclude_mem_range(struct crash_mem *mem,
+		unsigned long long mstart, unsigned long long mend)
+{
+	int i, j;
+	unsigned long long start, end;
+	struct crash_mem_range temp_range = {0, 0};
+
+	for (i = 0; i < mem->nr_ranges; i++) {
+		start = mem->ranges[i].start;
+		end = mem->ranges[i].end;
+
+		if (mstart > end || mend < start)
+			continue;
+
+		/* Truncate any area outside of range */
+		if (mstart < start)
+			mstart = start;
+		if (mend > end)
+			mend = end;
+
+		/* Found completely overlapping range */
+		if (mstart == start && mend == end) {
+			mem->ranges[i].start = 0;
+			mem->ranges[i].end = 0;
+			if (i < mem->nr_ranges - 1) {
+				/* Shift rest of the ranges to left */
+				for (j = i; j < mem->nr_ranges - 1; j++) {
+					mem->ranges[j].start =
+						mem->ranges[j+1].start;
+					mem->ranges[j].end =
+							mem->ranges[j+1].end;
+				}
+			}
+			mem->nr_ranges--;
+			return 0;
+		}
+
+		if (mstart > start && mend < end) {
+			/* Split original range */
+			mem->ranges[i].end = mstart - 1;
+			temp_range.start = mend + 1;
+			temp_range.end = end;
+		} else if (mstart != start)
+			mem->ranges[i].end = mstart - 1;
+		else
+			mem->ranges[i].start = mend + 1;
+		break;
+	}
+
+	/* If a split happened, add the split to array */
+	if (!temp_range.end)
+		return 0;
+
+	/* Split happened */
+	if (i == CRASH_MAX_RANGES - 1) {
+		pr_err("Too many crash ranges after split\n");
+		return -ENOMEM;
+	}
+
+	/* Location where new range should go */
+	j = i + 1;
+	if (j < mem->nr_ranges) {
+		/* Move over all ranges one slot towards the end */
+		for (i = mem->nr_ranges - 1; i >= j; i--)
+			mem->ranges[i + 1] = mem->ranges[i];
+	}
+
+	mem->ranges[j].start = temp_range.start;
+	mem->ranges[j].end = temp_range.end;
+	mem->nr_ranges++;
+	return 0;
+}
+
+/*
+ * Look for any unwanted ranges between mstart, mend and remove them. This
+ * might lead to split and split ranges are put in ced->mem.ranges[] array
+ */
+static int elf_header_exclude_ranges(struct crash_elf_data *ced,
+		unsigned long long mstart, unsigned long long mend)
+{
+	struct crash_mem *cmem = &ced->mem;
+	int ret = 0;
+
+	memset(cmem->ranges, 0, sizeof(cmem->ranges));
+
+	cmem->ranges[0].start = mstart;
+	cmem->ranges[0].end = mend;
+	cmem->nr_ranges = 1;
+
+	/* Exclude crashkernel region */
+	ret = exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
+	if (ret)
+		return ret;
+
+#ifdef CONFIG_X86_64
+	if (crashk_low_res.end) {
+		ret = exclude_mem_range(cmem, crashk_low_res.start,
+							crashk_low_res.end);
+		if (ret)
+			return ret;
+	}
+#endif
+
+	return ret;
+}
+
+static int prepare_elf64_ram_headers_callback(u64 start, u64 end, void *arg)
+{
+	struct crash_elf_data *ced = arg;
+	Elf64_Ehdr *ehdr;
+	Elf64_Phdr *phdr;
+	unsigned long mstart, mend;
+#ifdef CONFIG_X86_64
+	struct kimage *image = ced->image;
+#endif
+	struct crash_mem *cmem;
+	int ret, i;
+
+	ehdr = ced->ehdr;
+
+	/* Exclude unwanted mem ranges */
+	ret = elf_header_exclude_ranges(ced, start, end);
+	if (ret)
+		return ret;
+
+	/* Go through all the ranges in ced->mem.ranges[] and prepare phdr */
+	cmem = &ced->mem;
+
+	for (i = 0; i < cmem->nr_ranges; i++) {
+		mstart = cmem->ranges[i].start;
+		mend = cmem->ranges[i].end;
+
+		phdr = ced->bufp;
+		ced->bufp += sizeof(Elf64_Phdr);
+
+		phdr->p_type = PT_LOAD;
+		phdr->p_flags = PF_R|PF_W|PF_X;
+		phdr->p_offset  = mstart;
+
+#ifdef CONFIG_X86_64
+		/*
+		 * If a range matches backup region, adjust offset to backup
+		 * segment.
+		 */
+		if (mstart == image->arch.backup_src_start &&
+		    (mend - mstart + 1) == image->arch.backup_src_sz)
+			phdr->p_offset = image->arch.backup_load_addr;
+#endif
+
+		phdr->p_paddr = mstart;
+		phdr->p_vaddr = (unsigned long long) __va(mstart);
+		phdr->p_filesz = phdr->p_memsz = mend - mstart + 1;
+		phdr->p_align = 0;
+		ehdr->e_phnum++;
+		pr_debug("Crash PT_LOAD elf header. phdr=%p vaddr=0x%llx, paddr=0x%llx, sz=0x%llx e_phnum=%d p_offset=0x%llx\n",
+			phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz,
+			ehdr->e_phnum, phdr->p_offset);
+	}
+
+	return ret;
+}
+
+static int prepare_elf64_headers(struct crash_elf_data *ced,
+		void **addr, unsigned long *sz)
+{
+	Elf64_Ehdr *ehdr;
+	Elf64_Phdr *phdr;
+	unsigned long nr_cpus = num_possible_cpus(), nr_phdr, elf_sz;
+	unsigned char *buf, *bufp;
+	unsigned int cpu;
+	unsigned long long notes_addr;
+	int ret;
+
+	/* extra phdr for vmcoreinfo elf note */
+	nr_phdr = nr_cpus + 1;
+	nr_phdr += ced->max_nr_ranges;
+
+	/*
+	 * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping
+	 * area on x86_64 (ffffffff80000000 - ffffffffa0000000).
+	 * I think this is required by tools like gdb. So same physical
+	 * memory will be mapped in two elf headers. One will contain kernel
+	 * text virtual addresses and other will have __va(physical) addresses.
+	 */
+
+	nr_phdr++;
+	elf_sz = sizeof(Elf64_Ehdr) + nr_phdr * sizeof(Elf64_Phdr);
+	elf_sz = ALIGN(elf_sz, ELF_CORE_HEADER_ALIGN);
+
+	buf = vzalloc(elf_sz);
+	if (!buf)
+		return -ENOMEM;
+
+	bufp = buf;
+	ehdr = (Elf64_Ehdr *)bufp;
+	bufp += sizeof(Elf64_Ehdr);
+	memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
+	ehdr->e_ident[EI_CLASS] = ELFCLASS64;
+	ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
+	ehdr->e_ident[EI_VERSION] = EV_CURRENT;
+	ehdr->e_ident[EI_OSABI] = ELF_OSABI;
+	memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
+	ehdr->e_type = ET_CORE;
+	ehdr->e_machine = ELF_ARCH;
+	ehdr->e_version = EV_CURRENT;
+	ehdr->e_phoff = sizeof(Elf64_Ehdr);
+	ehdr->e_ehsize = sizeof(Elf64_Ehdr);
+	ehdr->e_phentsize = sizeof(Elf64_Phdr);
+
+	/* Prepare one phdr of type PT_NOTE for each present cpu */
+	for_each_present_cpu(cpu) {
+		phdr = (Elf64_Phdr *)bufp;
+		bufp += sizeof(Elf64_Phdr);
+		phdr->p_type = PT_NOTE;
+		notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu));
+		phdr->p_offset = phdr->p_paddr = notes_addr;
+		phdr->p_filesz = phdr->p_memsz = sizeof(note_buf_t);
+		(ehdr->e_phnum)++;
+	}
+
+	/* Prepare one PT_NOTE header for vmcoreinfo */
+	phdr = (Elf64_Phdr *)bufp;
+	bufp += sizeof(Elf64_Phdr);
+	phdr->p_type = PT_NOTE;
+	phdr->p_offset = phdr->p_paddr = paddr_vmcoreinfo_note();
+	phdr->p_filesz = phdr->p_memsz = VMCOREINFO_NOTE_SIZE;
+	(ehdr->e_phnum)++;
+
+#ifdef CONFIG_X86_64
+	/* Prepare PT_LOAD type program header for kernel text region */
+	phdr = (Elf64_Phdr *)bufp;
+	bufp += sizeof(Elf64_Phdr);
+	phdr->p_type = PT_LOAD;
+	phdr->p_flags = PF_R|PF_W|PF_X;
+	phdr->p_vaddr = (Elf64_Addr)_text;
+	phdr->p_filesz = phdr->p_memsz = _end - _text;
+	phdr->p_offset = phdr->p_paddr = __pa_symbol(_text);
+	(ehdr->e_phnum)++;
+#endif
+
+	/* Prepare PT_LOAD headers for system ram chunks. */
+	ced->ehdr = ehdr;
+	ced->bufp = bufp;
+	ret = walk_system_ram_res(0, -1, ced,
+			prepare_elf64_ram_headers_callback);
+	if (ret < 0)
+		return ret;
+
+	*addr = buf;
+	*sz = elf_sz;
+	return 0;
+}
+
+/* Prepare elf headers. Return addr and size */
+int prepare_elf_headers(struct kimage *image, void **addr, unsigned long *sz)
+{
+	struct crash_elf_data *ced;
+	int ret;
+
+	ced = kzalloc(sizeof(*ced), GFP_KERNEL);
+	if (!ced)
+		return -ENOMEM;
+
+	fill_up_crash_elf_data(ced, image);
+
+	/* By default prepare 64bit headers */
+	ret =  prepare_elf64_headers(ced, addr, sz);
+	kfree(ced);
+	return ret;
+}
+#endif /* CONFIG_CRASH_CORE */
-- 
2.14.1

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#1730670 — Re: [PATCH 3/9] kexec_file: factor out crashdump elf header function from x86

Hi,
On 09/08/17 at 12:16pm, AKASHI Takahiro wrote:
[snip]
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -162,6 +162,25 @@ int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
>  			       int (*func)(u64, u64, void *));
>  extern int kexec_add_buffer(struct kexec_buf *kbuf);
>  int kexec_locate_mem_hole(struct kexec_buf *kbuf);
> +#ifdef CONFIG_CRASH_CORE
> +extern int prepare_elf_headers(struct kimage *image, void **addr,
> +				unsigned long *sz);
> +
> +/* This primarily represents number of split ranges due to exclusion */
> +#define CRASH_MAX_RANGES        16
> +
> +struct crash_mem_range {
> +	u64 start, end;
> +};
> +
> +struct crash_mem {
> +	unsigned int nr_ranges;
> +	struct crash_mem_range ranges[CRASH_MAX_RANGES];
> +};
> +
> +extern int exclude_mem_range(struct crash_mem *mem,
> +		unsigned long long mstart, unsigned long long mend);
> +#endif /* CONFIG_CRASH_CORE */

Maybe I did not say it clear when reviewing the v1.

I suggested to move the code from to kexec_file.c because the
CONFIG_CRASH_CORE originally was introduced for the common code for
vmcoreinfo stuff when Hari worked on sharing code between powerpc
fadump and kdump.

I'm not sure we need the #ifdef CONFIG_CRASH_CORE here for these
kexec file load functions. Since they are already in kexec_file.c
so I think no need to add the #ifdef

>  #endif /* CONFIG_KEXEC_FILE */
Thanks
Dave

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#1731311 — Re: [PATCH 3/9] kexec_file: factor out crashdump elf header function from x86

On Tue, Sep 12, 2017 at 01:55:21PM +0800, Dave Young wrote:
> Hi,
> On 09/08/17 at 12:16pm, AKASHI Takahiro wrote:
> [snip]
> > --- a/include/linux/kexec.h
> > +++ b/include/linux/kexec.h
> > @@ -162,6 +162,25 @@ int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
> >  			       int (*func)(u64, u64, void *));
> >  extern int kexec_add_buffer(struct kexec_buf *kbuf);
> >  int kexec_locate_mem_hole(struct kexec_buf *kbuf);
> > +#ifdef CONFIG_CRASH_CORE
> > +extern int prepare_elf_headers(struct kimage *image, void **addr,
> > +				unsigned long *sz);
> > +
> > +/* This primarily represents number of split ranges due to exclusion */
> > +#define CRASH_MAX_RANGES        16
> > +
> > +struct crash_mem_range {
> > +	u64 start, end;
> > +};
> > +
> > +struct crash_mem {
> > +	unsigned int nr_ranges;
> > +	struct crash_mem_range ranges[CRASH_MAX_RANGES];
> > +};
> > +
> > +extern int exclude_mem_range(struct crash_mem *mem,
> > +		unsigned long long mstart, unsigned long long mend);
> > +#endif /* CONFIG_CRASH_CORE */
> 
> Maybe I did not say it clear when reviewing the v1.
> 
> I suggested to move the code from to kexec_file.c because the

(from crash_core.c)

> CONFIG_CRASH_CORE originally was introduced for the common code for
> vmcoreinfo stuff when Hari worked on sharing code between powerpc
> fadump and kdump.
> 
> I'm not sure we need the #ifdef CONFIG_CRASH_CORE here for these
> kexec file load functions. Since they are already in kexec_file.c
> so I think no need to add the #ifdef

Right. CRASH_CORE is always selected, in arch/Kconfig, by KEXEC_CORE
which is selected by KEXEC_FILE.
(In this sense, CRASH_CORE has no use any more.)

Thanks,
-Takahiro AKASHI

> >  #endif /* CONFIG_KEXEC_FILE */
> Thanks
> Dave

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