Carry forward IMA measurement log on kexec on ARM64

ELF related fields elf_headers, elf_headers_sz, and elf_load_addr are defined in architecture specific 'struct kimage_arch' for x86, powerpc, and arm64. The name of these fields are different in these architectures that makes it hard to have a common code for setting up the device tree for kexec system call.

Move the ELF fields to 'struct kimage' defined in include/linux/kexec.h so common code can use it.

Signed-off-by Lakshmi Ramasubramanian <[email protected]>

Suggested-by Rob Herring <[email protected]>

Fixes 33488dc4d61f ("of: Add a common kexec FDT setup function")

Reported-by kernel test robot <[email protected]>

---
 include/linux/kexec.h | 5 +++++
 1 file changed, 5 insertions(+)

ELF related fields elf_headers, elf_headers_sz, and elf_headers_mem have been moved from 'struct kimage_arch' to 'struct kimage' as elf_headers, elf_headers_sz, and elf_load_addr respectively.

Use the ELF fields defined in 'struct kimage'.

Signed-off-by Lakshmi Ramasubramanian <[email protected]>

Suggested-by Rob Herring <[email protected]>

Fixes 33488dc4d61f ("of: Add a common kexec FDT setup function")

Reported-by kernel test robot <[email protected]>

---
 arch/arm64/include/asm/kexec.h         |  4 ----
 arch/arm64/kernel/machine_kexec_file.c | 18 +++++++++---------
 2 files changed, 9 insertions(+), 13 deletions(-)

ELF related fields elf_headers, elf_headers_sz, and elfcorehdr_addr have been moved from 'struct kimage_arch' to 'struct kimage' as elf_headers, elf_headers_sz, and elf_load_addr respectively.

Use the ELF fields defined in 'struct kimage'.

Signed-off-by Lakshmi Ramasubramanian <[email protected]>

Suggested-by Rob Herring <[email protected]>

Fixes 33488dc4d61f ("of: Add a common kexec FDT setup function")

Reported-by kernel test robot <[email protected]>

---
 arch/powerpc/include/asm/kexec.h  |  4 ----
 arch/powerpc/kexec/file_load.c    |  6 +++---
 arch/powerpc/kexec/file_load_64.c | 14 +++++++-------
 3 files changed, 10 insertions(+), 14 deletions(-)

ELF related fields elf_headers, elf_headers_sz, and elf_load_addr have been moved from 'struct kimage_arch' to 'struct kimage'.

Use the ELF fields defined in 'struct kimage'.

Signed-off-by Lakshmi Ramasubramanian <[email protected]>

Suggested-by Rob Herring <[email protected]>

Fixes 33488dc4d61f ("of: Add a common kexec FDT setup function")

Reported-by kernel test robot <[email protected]>

---
 arch/x86/include/asm/kexec.h       |  5 -----
 arch/x86/kernel/crash.c            | 14 +++++++-------
 arch/x86/kernel/kexec-bzimage64.c  |  2 +-
 arch/x86/kernel/machine_kexec_64.c |  4 ++--
 4 files changed, 10 insertions(+), 15 deletions(-)

ELF related fields elf_headers, elf_headers_sz, and elf_load_addr have been moved from 'struct kimage_arch' to 'struct kimage'.

Use the ELF fields defined in 'struct kimage'.

Signed-off-by Lakshmi Ramasubramanian <[email protected]>

Suggested-by Rob Herring <[email protected]>

Fixes 33488dc4d61f ("of: Add a common kexec FDT setup function")

Reported-by kernel test robot <[email protected]>

---
 arch/x86/include/asm/kexec.h       |  5 -----
 arch/x86/kernel/crash.c            | 14 +++++++-------
 arch/x86/kernel/kexec-bzimage64.c  |  2 +-
 arch/x86/kernel/machine_kexec_64.c |  4 ++--
 4 files changed, 10 insertions(+), 15 deletions(-)

From: Rob Herring <[email protected]>

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 <[email protected]>

Signed-off-by Lakshmi Ramasubramanian <[email protected]>

Fixes 33488dc4d61f ("of: Add a common kexec FDT setup function")

Reported-by kernel test robot <[email protected]>

---
 drivers/of/Makefile |   6 +
 drivers/of/kexec.c  | 265 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/of.h  |   5 +
 3 files changed, 276 insertions(+)
 create mode 100644 drivers/of/kexec.c

Quoted 22 lines · Lakshmi Ramasubramanian

From: Rob Herring <[email protected]>

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".

Quoted 3 lines

Signed-off-by Rob Herring <[email protected]>

Signed-off-by Lakshmi Ramasubramanian <[email protected]>

Fixes 33488dc4d61f ("of: Add a common kexec FDT setup function")

A patch cannot fix itself. The world would be a much better place if it could. :-)

Quoted 8 lines

Reported-by kernel test robot <[email protected]>

---
  drivers/of/Makefile |   6 +
  drivers/of/kexec.c  | 265 ++++++++++++++++++++++++++++++++++++++++++++
  include/linux/of.h  |   5 +
  3 files changed, 276 insertions(+)

create mode 100644 drivers/of/kexec.c

With that fixed:

Reviewed-by Thiago Jung Bauermann <[email protected]>

From: Rob Herring <[email protected]>

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 <[email protected]>

Signed-off-by Lakshmi Ramasubramanian <[email protected]>

drivers/of/kexec.c new file +21 -0

 
+/*
+ * 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.
+ * @extra_fdt_size:    Additional size for the new FDT buffer.
+ *
+ * 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, size_t extra_fdt_size)
+{
 
+       /* 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;

drivers/of/kexec.c new file +29 -0

+
+               /*
+                * 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;

Hi Lakshmi and Rob,

Quoted 55 lines · Lakshmi Ramasubramanian

From: Rob Herring <[email protected]>

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 <[email protected]>

Signed-off-by Lakshmi Ramasubramanian <[email protected]>

drivers/of/kexec.c new file +26 -0

 
+/*
+ * 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.
+ * @extra_fdt_size:    Additional size for the new FDT buffer.
+ *
+ * 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, size_t extra_fdt_size)
+{
 
+       /* 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) {

drivers/of/kexec.c line 145

Quoted 5 lines

drivers/of/kexec.c new file +5 -0

+                       ret = -EINVAL;
+                       goto out;
+               }
+
+               tmp_end = fdt64_to_cpu(*((const fdt64_t *) prop));

Some kernel code assumes "linux,initrd-{start,end}" are 64-bit, other code assumes 32-bit.

linux/Documentation/arm/uefi.rst says 64-bit,
dt-schema/schemas/chosen.yaml says 32-bit.

Quoted 21 lines · Geert Uytterhoeven

Quoted 21 lines

(quoted diff) +2 -0

+void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
+                                  unsigned long

initrd_load_addr,

(quoted diff) +2 -0

+                                  unsigned long initrd_len,
+                                  const char *cmdline, size_t

extra_fdt_size)

drivers/of/kexec.c new file +3 -0

+{
+       /* Did we boot using an initrd? */
+       prop = fdt_getprop(fdt, chosen_node, "linux,initrd-

start", NULL);

drivers/of/kexec.c new file +4 -0

+       if (prop) {
+               u64 tmp_start, tmp_end, tmp_size;
+
+               tmp_start = fdt64_to_cpu(*((const fdt64_t *)

prop));

(quoted diff) +2 -0

+
+               prop = fdt_getprop(fdt, chosen_node,

"linux,initrd-end", NULL);

drivers/of/kexec.c new file +2 -0

+               if (!prop) {
+                       ret = -EINVAL;

Quoted 8 lines

Quoted 5 lines

drivers/of/kexec.c new file +4 -0

+                       goto out;
+               }
+
+               tmp_end = fdt64_to_cpu(*((const fdt64_t *)

prop));

Some kernel code assumes "linux,initrd-{start,end}" are 64-bit, other code assumes 32-bit.

It can be either. The above code was a merge of arm64 and powerpc both
of which use 64-bit and still only runs on those arches. It looks like
some powerpc platforms may use 32-bit, but this would have been broken
before.

The code in drivers/of/fdt.c handles either case. We should probably refactor early_init_dt_check_for_initrd() and this function to use a common routine.

Quoted 2 lines

linux/Documentation/arm/uefi.rst says 64-bit,
dt-schema/schemas/chosen.yaml says 32-bit.

We should fix that.

Rob

Quoted 32 lines · Rob Herring

Quoted 21 lines · Geert Uytterhoeven

Quoted 21 lines

(quoted diff) +2 -0

+void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
+                                  unsigned long

initrd_load_addr,

(quoted diff) +2 -0

+                                  unsigned long initrd_len,
+                                  const char *cmdline, size_t

extra_fdt_size)

drivers/of/kexec.c new file +3 -0

+{
+       /* Did we boot using an initrd? */
+       prop = fdt_getprop(fdt, chosen_node, "linux,initrd-

start", NULL);

drivers/of/kexec.c new file +4 -0

+       if (prop) {
+               u64 tmp_start, tmp_end, tmp_size;
+
+               tmp_start = fdt64_to_cpu(*((const fdt64_t *)

prop));

(quoted diff) +2 -0

+
+               prop = fdt_getprop(fdt, chosen_node,

"linux,initrd-end", NULL);

drivers/of/kexec.c new file +2 -0

+               if (!prop) {
+                       ret = -EINVAL;

Quoted 8 lines

Quoted 5 lines

drivers/of/kexec.c new file +4 -0

+                       goto out;
+               }
+
+               tmp_end = fdt64_to_cpu(*((const fdt64_t *)

prop));

Some kernel code assumes "linux,initrd-{start,end}" are 64-bit, other code assumes 32-bit.

Quoted 7 lines

It can be either. The above code was a merge of arm64 and powerpc both
of which use 64-bit and still only runs on those arches. It looks like
some powerpc platforms may use 32-bit, but this would have been broken
before.

of_kexec_alloc_and_setup_fdt() is called from elf_64.c (in arch/powerpc/kexec) which is for 64-bit powerpc platform only.

Quoted 34 lines · nramas

Quoted 32 lines · Rob Herring

Quoted 29 lines · Geert Uytterhoeven

Quoted 25 lines

(quoted diff) +2 -0

+void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
+                                  unsigned long

initrd_load_addr,

(quoted diff) +2 -0

+                                  unsigned long initrd_len,
+                                  const char *cmdline, size_t

extra_fdt_size)

drivers/of/kexec.c new file +3 -0

+{
+       /* Did we boot using an initrd? */
+       prop = fdt_getprop(fdt, chosen_node, "linux,initrd-

start", NULL);

drivers/of/kexec.c new file +4 -0

+       if (prop) {
+               u64 tmp_start, tmp_end, tmp_size;
+
+               tmp_start = fdt64_to_cpu(*((const fdt64_t *)

prop));

(quoted diff) +2 -0

+
+               prop = fdt_getprop(fdt, chosen_node,

"linux,initrd-end", NULL);

drivers/of/kexec.c new file +6 -0

+               if (!prop) {
+                       ret = -EINVAL;
+                       goto out;
+               }
+
+               tmp_end = fdt64_to_cpu(*((const fdt64_t *)

Quoted 1 line

prop));

Some kernel code assumes "linux,initrd-{start,end}" are 64-bit, other code assumes 32-bit.

Quoted 7 lines

Quoted 4 lines

It can be either. The above code was a merge of arm64 and powerpc >> > both of which use 64-bit and still only runs on those arches. It looks >> > like some powerpc platforms may use 32-bit, but this would have been >> > broken before.

of_kexec_alloc_and_setup_fdt() is called from elf_64.c (in arch/powerpc/kexec) which is for 64-bit powerpc platform only.

64-bit PPC could be writing 32-bit property values. The architecture size doesn't necessarily matter. And if the values came from the bootloader, who knows what size it used.

This code is 32-bit powerpc only?:

arch/powerpc/boot/main.c-       /* Tell the kernel initrd address via device tree */
arch/powerpc/boot/main.c:       setprop_val(chosen, "linux,initrd-start", (u32)(initrd_addr));
arch/powerpc/boot/main.c-       setprop_val(chosen, "linux,initrd-end", (u32)(initrd_addr+initrd_size));

Quoted 49 lines · Rob Herring

Quoted 34 lines · nramas

Quoted 32 lines · Rob Herring

Quoted 29 lines · Geert Uytterhoeven

Quoted 25 lines

(quoted diff) +2 -0

+void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
+                                  unsigned long

initrd_load_addr,

(quoted diff) +2 -0

+                                  unsigned long initrd_len,
+                                  const char *cmdline, size_t

extra_fdt_size)

drivers/of/kexec.c new file +3 -0

+{
+       /* Did we boot using an initrd? */
+       prop = fdt_getprop(fdt, chosen_node, "linux,initrd-

start", NULL);

drivers/of/kexec.c new file +4 -0

+       if (prop) {
+               u64 tmp_start, tmp_end, tmp_size;
+
+               tmp_start = fdt64_to_cpu(*((const fdt64_t *)

prop));

(quoted diff) +2 -0

+
+               prop = fdt_getprop(fdt, chosen_node,

"linux,initrd-end", NULL);

drivers/of/kexec.c new file +6 -0

+               if (!prop) {
+                       ret = -EINVAL;
+                       goto out;
+               }
+
+               tmp_end = fdt64_to_cpu(*((const fdt64_t *)

Quoted 1 line

prop));

Some kernel code assumes "linux,initrd-{start,end}" are 64-bit, other code assumes 32-bit.

Quoted 7 lines

Quoted 4 lines

It can be either. The above code was a merge of arm64 and powerpc >> > both of which use 64-bit and still only runs on those arches. It looks >> > like some powerpc platforms may use 32-bit, but this would have been >> > broken before.

of_kexec_alloc_and_setup_fdt() is called from elf_64.c (in arch/powerpc/kexec) which is for 64-bit powerpc platform only.

64-bit PPC could be writing 32-bit property values. The architecture size doesn't necessarily matter. And if the values came from the bootloader, who knows what size it used.

This code is 32-bit powerpc only?:

Quoted 3 lines

arch/powerpc/boot/main.c-       /* Tell the kernel initrd address via device tree */
arch/powerpc/boot/main.c:       setprop_val(chosen, "linux,initrd-start", (u32)(initrd_addr));
arch/powerpc/boot/main.c-       setprop_val(chosen, "linux,initrd-end", (u32)(initrd_addr+initrd_size));

Historically that code was always built 32-bit, even when used with a 64-bit kernel.

These days it is also built 64-bit (for ppc64le).

It looks like the drivers/of/fdt.c code can handle either 64 or 32-bit, so I guess that's why it seems to be working.

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 f31e3386a4e9 ("ima: Free IMA measurement buffer after kexec syscall") in https://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git
"ima-kexec-fixes" branch.

Changelog:

v19
- Moved ELF related fields from "struct kimage_arch" for x86, arm64, and powerpc architectures to "struct kimage".

v18
- Added a parameter to of_kexec_alloc_and_setup_fdt() for the caller to specify additional space needed for the FDT buffer
- Renamed arm64 and powerpc ELF buffer address field in "struct kimage_arch" to elf_load_addr to match x86_64 name.
- Removed of_ima_add_kexec_buffer() and instead directly set ima_buffer_addr and ima_buffer_size in ima_add_kexec_buffer()
- Moved FDT_EXTRA_SPACE definition from include/linux/of.h to drivers/of/kexec.c

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 <[email protected]>
- 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 (10):
kexec: Move ELF fields to struct kimage
arm64: Use ELF fields defined in 'struct kimage'
powerpc: Use ELF fields defined in 'struct kimage'
x86: Use ELF fields defined in 'struct kimage'
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 (3):
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/include/asm/kexec.h         |   4 -
 arch/arm64/kernel/machine_kexec_file.c | 194 +----------
 arch/powerpc/Kconfig                   |   2 +-
 arch/powerpc/include/asm/ima.h         |  30 --
 arch/powerpc/include/asm/kexec.h       |  14 +-
 arch/powerpc/kexec/Makefile            |   7 -
 arch/powerpc/kexec/elf_64.c            |  30 +-
 arch/powerpc/kexec/file_load.c         | 183 +---------
 arch/powerpc/kexec/file_load_64.c      |  21 +-
 arch/powerpc/kexec/ima.c               | 219 ------------
 arch/x86/include/asm/kexec.h           |   5 -
 arch/x86/kernel/crash.c                |  14 +-
 arch/x86/kernel/kexec-bzimage64.c      |   2 +-
 arch/x86/kernel/machine_kexec_64.c     |   4 +-
 drivers/of/Makefile                    |   6 +
 drivers/of/kexec.c                     | 458 +++++++++++++++++++++++++

 include/linux/kexec.h                  |   8 +
 include/linux/of.h                     |   7 +
 security/integrity/ima/ima.h           |   4 -
 security/integrity/ima/ima_kexec.c     |   9 +-
 21 files changed, 539 insertions(+), 683 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

Quoted 28 lines · 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 f31e3386a4e9 ("ima: Free IMA measurement buffer after kexec syscall") in https://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git
"ima-kexec-fixes" branch.

Quoted 41 lines

Lakshmi Ramasubramanian (10):
kexec: Move ELF fields to struct kimage
arm64: Use ELF fields defined in 'struct kimage'
powerpc: Use ELF fields defined in 'struct kimage'
x86: Use ELF fields defined in 'struct kimage'
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 (3):
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/include/asm/kexec.h         |   4 -
  arch/arm64/kernel/machine_kexec_file.c | 194 +----------
  arch/powerpc/Kconfig                   |   2 +-
  arch/powerpc/include/asm/ima.h         |  30 --
  arch/powerpc/include/asm/kexec.h       |  14 +-
  arch/powerpc/kexec/Makefile            |   7 -
  arch/powerpc/kexec/elf_64.c            |  30 +-
  arch/powerpc/kexec/file_load.c         | 183 +---------
  arch/powerpc/kexec/file_load_64.c      |  21 +-
  arch/powerpc/kexec/ima.c               | 219 ------------
  arch/x86/include/asm/kexec.h           |   5 -
  arch/x86/kernel/crash.c                |  14 +-
  arch/x86/kernel/kexec-bzimage64.c      |   2 +-
  arch/x86/kernel/machine_kexec_64.c     |   4 +-
  drivers/of/Makefile                    |   6 +
  drivers/of/kexec.c                     | 458 +++++++++++++++++++++++++
  include/linux/kexec.h                  |   8 +
  include/linux/of.h                     |   7 +
  security/integrity/ima/ima.h           |   4 -
  security/integrity/ima/ima_kexec.c     |   9 +-
  21 files changed, 539 insertions(+), 683 deletions(-)

Quoted 3 lines

delete mode 100644 arch/powerpc/include/asm/ima.h delete mode 100644 arch/powerpc/kexec/ima.c create mode 100644 drivers/of/kexec.c

I fixed up the Fixes tags and applied for 5.13.