[PATCH v7 0/3] Carry forward IMA measurement log on kexec on ARM64

[PATCH v7 0/3] Carry forward IMA measurement log on kexec on ARM64

[Lakshmi Ramasubramanian]

On kexec file load Integrity Measurement Architecture (IMA) subsystem
may verify the IMA signature of the kernel and initramfs, and measure
it. The command line parameters passed to the kernel in the kexec call
may also be measured by IMA. A remote attestation service can verify
the measurement through the IMA log 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.
However in the current implementation the IMA measurement logs are not
carried over on ARM64 platforms. Therefore a remote attestation service
cannot verify the authenticity of the running kernel on ARM64 platforms
when the kernel is updated through the kexec system call.

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

This series refactors the platform independent code defined for powerpc
such that it can be reused for ARM64 as well. A chosen node namely
"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 series has been tested for ARM64 platform using QEMU.
I would like help from the community for testing this change on powerpc.
Thanks.

This patch series is based on
commit 02de58b24d2e ("Merge tag 'devicetree-fixes-for-5.9-3' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux")
in https://github.com/torvalds/linux "master" branch.

Changelog:

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

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

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

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

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

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

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

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

Lakshmi Ramasubramanian (4):
  powerpc: Refactor kexec functions to move arch independent code to
    kernel
  powerpc: Refactor kexec functions to move arch independent code to ima
  arm64: Store IMA log information in kimage used for kexec
  arm64: Add IMA kexec buffer to DTB

 arch/arm64/Kconfig                     |   1 +
 arch/arm64/include/asm/ima.h           |  18 +++
 arch/arm64/include/asm/kexec.h         |   3 +
 arch/arm64/kernel/Makefile             |   1 +
 arch/arm64/kernel/ima_kexec.c          |  34 ++++++
 arch/arm64/kernel/machine_kexec_file.c |  18 +++
 arch/powerpc/include/asm/ima.h         |  13 +--
 arch/powerpc/include/asm/kexec.h       |   1 -
 arch/powerpc/kexec/Makefile            |   7 +-
 arch/powerpc/kexec/file_load.c         |  33 +-----
 arch/powerpc/kexec/ima.c               | 111 ++----------------
 include/linux/kexec.h                  |  24 ++++
 include/linux/libfdt.h                 |   3 +
 kernel/Makefile                        |   3 +-
 kernel/ima_kexec.c                     |  85 ++++++++++++++
 kernel/kexec_file_fdt.c                |  55 +++++++++
 security/integrity/ima/Makefile        |   1 +
 security/integrity/ima/ima_kexec.c     | 154 +++++++------------------
 security/integrity/ima/ima_kexec_fdt.c | 136 ++++++++++++++++++++++
 19 files changed, 438 insertions(+), 263 deletions(-)
 create mode 100644 arch/arm64/include/asm/ima.h
 create mode 100644 arch/arm64/kernel/ima_kexec.c
 create mode 100644 kernel/ima_kexec.c
 create mode 100644 kernel/kexec_file_fdt.c
 create mode 100644 security/integrity/ima/ima_kexec_fdt.c

-- 
2.28.0

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

[Lakshmi Ramasubramanian]

The functions remove_ima_buffer() and delete_fdt_mem_rsv() that handle
carrying forward the IMA measurement logs on kexec for powerpc do not
have architecture specific code, but they are currently defined for
powerpc only.

remove_ima_buffer() and delete_fdt_mem_rsv() are used to remove
the IMA log entry from the device tree and free the memory reserved
for the log. These functions need to be defined even if the current
kernel does not support carrying forward IMA log across kexec since
the previous kernel could have supported that and therefore the current
kernel needs to free the allocation.

Rename remove_ima_buffer() to remove_ima_kexec_buffer().
Define remove_ima_kexec_buffer() and delete_fdt_mem_rsv() in kernel.
A later patch in this series will use these functions to free
the allocation, if any, made by the previous kernel for ARM64.

Define FDT_PROP_IMA_KEXEC_BUFFER for the chosen node, namely
"linux,ima-kexec-buffer", that is added to the DTB to hold
the address and the size of the memory reserved to carry
the IMA measurement log.

Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reported-by: kernel test robot <lkp@intel.com> error: implicit declaration of function 'delete_fdt_mem_rsv' [-Werror,-Wimplicit-function-declaration]
---
 arch/powerpc/include/asm/ima.h   | 10 ++--
 arch/powerpc/include/asm/kexec.h |  1 -
 arch/powerpc/kexec/file_load.c   | 33 +------------
 arch/powerpc/kexec/ima.c         | 55 +++------------------
 include/linux/kexec.h            | 24 +++++++++
 include/linux/libfdt.h           |  3 ++
 kernel/Makefile                  |  3 +-
 kernel/ima_kexec.c               | 85 ++++++++++++++++++++++++++++++++
 kernel/kexec_file_fdt.c          | 55 +++++++++++++++++++++
 9 files changed, 181 insertions(+), 88 deletions(-)
 create mode 100644 kernel/ima_kexec.c
 create mode 100644 kernel/kexec_file_fdt.c

diff --git a/arch/powerpc/include/asm/ima.h b/arch/powerpc/include/asm/ima.h
index ead488cf3981..6355a85a3289 100644
--- a/arch/powerpc/include/asm/ima.h
+++ b/arch/powerpc/include/asm/ima.h
@@ -2,17 +2,13 @@
 #ifndef _ASM_POWERPC_IMA_H
 #define _ASM_POWERPC_IMA_H
 
+#include <linux/kexec.h>
+
 struct kimage;
 
 int ima_get_kexec_buffer(void **addr, size_t *size);
 int ima_free_kexec_buffer(void);
 
-#ifdef CONFIG_IMA
-void remove_ima_buffer(void *fdt, int chosen_node);
-#else
-static inline void remove_ima_buffer(void *fdt, int chosen_node) {}
-#endif
-
 #ifdef CONFIG_IMA_KEXEC
 int arch_ima_add_kexec_buffer(struct kimage *image, unsigned long load_addr,
 			      size_t size);
@@ -22,7 +18,7 @@ int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node);
 static inline int setup_ima_buffer(const struct kimage *image, void *fdt,
 				   int chosen_node)
 {
-	remove_ima_buffer(fdt, chosen_node);
+	remove_ima_kexec_buffer(fdt, chosen_node);
 	return 0;
 }
 #endif /* CONFIG_IMA_KEXEC */
diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index 55d6ede30c19..7c223031ecdd 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -126,7 +126,6 @@ int setup_purgatory(struct kimage *image, const void *slave_code,
 int setup_new_fdt(const struct kimage *image, void *fdt,
 		  unsigned long initrd_load_addr, unsigned long initrd_len,
 		  const char *cmdline);
-int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size);
 
 #ifdef CONFIG_PPC64
 struct kexec_buf;
diff --git a/arch/powerpc/kexec/file_load.c b/arch/powerpc/kexec/file_load.c
index 9a232bc36c8f..7a17655c530e 100644
--- a/arch/powerpc/kexec/file_load.c
+++ b/arch/powerpc/kexec/file_load.c
@@ -18,6 +18,7 @@
 #include <linux/kexec.h>
 #include <linux/of_fdt.h>
 #include <linux/libfdt.h>
+#include <linux/kexec.h>
 #include <asm/setup.h>
 #include <asm/ima.h>
 
@@ -109,38 +110,6 @@ int setup_purgatory(struct kimage *image, const void *slave_code,
 	return 0;
 }
 
-/**
- * delete_fdt_mem_rsv - delete memory reservation with given address and size
- *
- * Return: 0 on success, or negative errno on error.
- */
-int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size)
-{
-	int i, ret, num_rsvs = fdt_num_mem_rsv(fdt);
-
-	for (i = 0; i < num_rsvs; i++) {
-		uint64_t rsv_start, rsv_size;
-
-		ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
-		if (ret) {
-			pr_err("Malformed device tree.\n");
-			return -EINVAL;
-		}
-
-		if (rsv_start == start && rsv_size == size) {
-			ret = fdt_del_mem_rsv(fdt, i);
-			if (ret) {
-				pr_err("Error deleting device tree reservation.\n");
-				return -EINVAL;
-			}
-
-			return 0;
-		}
-	}
-
-	return -ENOENT;
-}
-
 /*
  * setup_new_fdt - modify /chosen and memory reservation for the next kernel
  * @image:		kexec image being loaded.
diff --git a/arch/powerpc/kexec/ima.c b/arch/powerpc/kexec/ima.c
index 720e50e490b6..2b790230ea15 100644
--- a/arch/powerpc/kexec/ima.c
+++ b/arch/powerpc/kexec/ima.c
@@ -11,6 +11,8 @@
 #include <linux/of.h>
 #include <linux/memblock.h>
 #include <linux/libfdt.h>
+#include <linux/ima.h>
+#include <asm/ima.h>
 
 static int get_addr_size_cells(int *addr_cells, int *size_cells)
 {
@@ -28,24 +30,6 @@ static int get_addr_size_cells(int *addr_cells, int *size_cells)
 	return 0;
 }
 
-static int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr,
-			       size_t *size)
-{
-	int ret, addr_cells, size_cells;
-
-	ret = get_addr_size_cells(&addr_cells, &size_cells);
-	if (ret)
-		return ret;
-
-	if (len < 4 * (addr_cells + size_cells))
-		return -ENOENT;
-
-	*addr = of_read_number(prop, addr_cells);
-	*size = of_read_number(prop + 4 * addr_cells, size_cells);
-
-	return 0;
-}
-
 /**
  * ima_get_kexec_buffer - get IMA buffer from the previous kernel
  * @addr:	On successful return, set to point to the buffer contents.
@@ -100,37 +84,14 @@ int ima_free_kexec_buffer(void)
 
 }
 
-/**
- * remove_ima_buffer - remove the IMA buffer property and reservation from @fdt
- *
- * The IMA measurement buffer is of no use to a subsequent kernel, so we always
- * remove it from the device tree.
- */
-void remove_ima_buffer(void *fdt, int chosen_node)
-{
-	int ret, len;
-	unsigned long addr;
-	size_t size;
-	const void *prop;
-
-	prop = fdt_getprop(fdt, chosen_node, "linux,ima-kexec-buffer", &len);
-	if (!prop)
-		return;
-
-	ret = do_get_kexec_buffer(prop, len, &addr, &size);
-	fdt_delprop(fdt, chosen_node, "linux,ima-kexec-buffer");
-	if (ret)
-		return;
-
-	ret = delete_fdt_mem_rsv(fdt, addr, size);
-	if (!ret)
-		pr_debug("Removed old IMA buffer reservation.\n");
-}
-
 #ifdef CONFIG_IMA_KEXEC
 /**
  * arch_ima_add_kexec_buffer - do arch-specific steps to add the IMA buffer
  *
+ * @image: kimage struct to set IMA buffer data
+ * @load_addr: Starting address where IMA buffer is loaded at
+ * @size: Number of bytes in the IMA buffer
+ *
  * Architectures should use this function to pass on the IMA buffer
  * information to the next kernel.
  *
@@ -179,7 +140,7 @@ int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node)
 	int ret, addr_cells, size_cells, entry_size;
 	u8 value[16];
 
-	remove_ima_buffer(fdt, chosen_node);
+	remove_ima_kexec_buffer(fdt, chosen_node);
 	if (!image->arch.ima_buffer_size)
 		return 0;
 
@@ -201,7 +162,7 @@ int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node)
 	if (ret)
 		return ret;
 
-	ret = fdt_setprop(fdt, chosen_node, "linux,ima-kexec-buffer", value,
+	ret = fdt_setprop(fdt, chosen_node, FDT_PROP_IMA_KEXEC_BUFFER, value,
 			  entry_size);
 	if (ret < 0)
 		return -EINVAL;
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 9e93bef52968..39a931df6ae4 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -407,6 +407,30 @@ static inline int kexec_crash_loaded(void) { return 0; }
 #define kexec_in_progress false
 #endif /* CONFIG_KEXEC_CORE */
 
+#ifdef CONFIG_HAVE_IMA_KEXEC
+extern void remove_ima_kexec_buffer(void *fdt, int chosen_node);
+extern int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr,
+			       size_t *size);
+#else
+static inline void remove_ima_kexec_buffer(void *fdt, int chosen_node) {}
+static inline int do_get_kexec_buffer(const void *prop, int len,
+				      unsigned long *addr, size_t *size)
+{
+	return -EOPNOTSUPP;
+}
+#endif /* CONFIG_HAVE_IMA_KEXEC */
+
+#ifdef CONFIG_KEXEC_FILE
+extern int delete_fdt_mem_rsv(void *fdt, unsigned long start,
+			      unsigned long size);
+#else
+static inline int delete_fdt_mem_rsv(void *fdt, unsigned long start,
+				     unsigned long size)
+{
+	return 0;
+}
+#endif /* CONFIG_KEXEC_FILE */
+
 #endif /* !defined(__ASSEBMLY__) */
 
 #endif /* LINUX_KEXEC_H */
diff --git a/include/linux/libfdt.h b/include/linux/libfdt.h
index 90ed4ebfa692..75fb40aa013b 100644
--- a/include/linux/libfdt.h
+++ b/include/linux/libfdt.h
@@ -5,4 +5,7 @@
 #include <linux/libfdt_env.h>
 #include "../../scripts/dtc/libfdt/libfdt.h"
 
+/* Common device tree properties */
+#define FDT_PROP_IMA_KEXEC_BUFFER	"linux,ima-kexec-buffer"
+
 #endif /* _INCLUDE_LIBFDT_H_ */
diff --git a/kernel/Makefile b/kernel/Makefile
index 9a20016d4900..f20bb423291a 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -71,8 +71,9 @@ obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
 obj-$(CONFIG_CRASH_CORE) += crash_core.o
 obj-$(CONFIG_KEXEC_CORE) += kexec_core.o
 obj-$(CONFIG_KEXEC) += kexec.o
-obj-$(CONFIG_KEXEC_FILE) += kexec_file.o
+obj-$(CONFIG_KEXEC_FILE) += kexec_file.o kexec_file_fdt.o
 obj-$(CONFIG_KEXEC_ELF) += kexec_elf.o
+obj-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o
 obj-$(CONFIG_BACKTRACE_SELF_TEST) += backtracetest.o
 obj-$(CONFIG_COMPAT) += compat.o
 obj-$(CONFIG_CGROUPS) += cgroup/
diff --git a/kernel/ima_kexec.c b/kernel/ima_kexec.c
new file mode 100644
index 000000000000..6fb6e4b862aa
--- /dev/null
+++ b/kernel/ima_kexec.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Microsoft Corporation
+ *
+ * Author: Lakshmi Ramasubramanian (nramas@linux.microsoft.com)
+ *
+ * ima_kexec.c
+ *	Handle IMA buffer for kexec
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/types.h>
+#include <linux/err.h>
+#include <linux/printk.h>
+#include <linux/libfdt.h>
+#include <linux/of.h>
+#include <linux/kexec.h>
+
+/**
+ * do_get_kexec_buffer - Get address and size of IMA kexec buffer
+ *
+ * @prop: IMA kexec buffer node in the device tree
+ * @len: Size of the given device tree node property
+ * @addr: Return address of the node
+ * @size: Return size of the node
+ */
+int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr,
+			size_t *size)
+{
+	int addr_cells, size_cells;
+	struct device_node *root;
+
+	root = of_find_node_by_path("/");
+	if (!root)
+		return -EINVAL;
+
+	addr_cells = of_n_addr_cells(root);
+	size_cells = of_n_size_cells(root);
+
+	of_node_put(root);
+
+	if (len < 4 * (addr_cells + size_cells))
+		return -ENOENT;
+
+	*addr = of_read_number(prop, addr_cells);
+	*size = of_read_number(prop + 4 * addr_cells, size_cells);
+
+	return 0;
+}
+
+/**
+ * remove_ima_kexec_buffer - remove the IMA buffer property and
+ *			     reservation from @fdt
+ *
+ * @fdt: Flattened Device Tree to update
+ * @chosen_node: Offset to the chosen node in the device tree
+ *
+ * The IMA measurement buffer is of no use to a subsequent kernel,
+ * so we always remove it from the device tree.
+ */
+void remove_ima_kexec_buffer(void *fdt, int chosen_node)
+{
+	int ret, len;
+	unsigned long addr;
+	size_t size;
+	const void *prop;
+
+	prop = fdt_getprop(fdt, chosen_node, FDT_PROP_IMA_KEXEC_BUFFER, &len);
+	if (!prop) {
+		pr_debug("Unable to find the ima kexec buffer node\n");
+		return;
+	}
+
+	ret = do_get_kexec_buffer(prop, len, &addr, &size);
+	fdt_delprop(fdt, chosen_node, FDT_PROP_IMA_KEXEC_BUFFER);
+	if (ret) {
+		pr_err("Unable to delete the ima kexec buffer node\n");
+		return;
+	}
+
+	ret = delete_fdt_mem_rsv(fdt, addr, size);
+	if (!ret)
+		pr_debug("Removed old IMA buffer reservation.\n");
+}
diff --git a/kernel/kexec_file_fdt.c b/kernel/kexec_file_fdt.c
new file mode 100644
index 000000000000..726e43254892
--- /dev/null
+++ b/kernel/kexec_file_fdt.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Microsoft Corporation
+ *
+ * Author: Lakshmi Ramasubramanian (nramas@linux.microsoft.com)
+ *
+ * kexec_file_fdt.c
+ *	Handle memory reservation in device tree.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/types.h>
+#include <linux/err.h>
+#include <linux/printk.h>
+#include <linux/libfdt.h>
+#include <linux/kexec.h>
+
+/**
+ * delete_fdt_mem_rsv - delete memory reservation with given address and size
+ *
+ * @fdt: Flattened Device Tree to update
+ * @start: Starting address of the reservation to delete
+ * @size: Size of the reservation to delete
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size)
+{
+	int i, ret, num_rsvs = fdt_num_mem_rsv(fdt);
+
+	for (i = 0; i < num_rsvs; i++) {
+		uint64_t rsv_start, rsv_size;
+
+		ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
+		if (ret) {
+			pr_err("Malformed device tree.\n");
+			return -EINVAL;
+		}
+
+		if (rsv_start == start && rsv_size == size) {
+			ret = fdt_del_mem_rsv(fdt, i);
+			if (ret) {
+				pr_err("Error deleting device tree reservation.\n");
+				return -EINVAL;
+			}
+
+			pr_debug("Freed reserved memory at %lu of size %lu\n",
+				 start, size);
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
-- 
2.28.0

[PATCH v7 2/4] powerpc: Refactor kexec functions to move arch independent code to ima

[Lakshmi Ramasubramanian]

The functions ima_get_kexec_buffer() and ima_free_kexec_buffer(),
that handle carrying forward the IMA measurement logs on kexec for
powerpc do not have architecture specific code, but they are currently
defined for powerpc only.

Move ima_get_kexec_buffer() and ima_free_kexec_buffer() to IMA
subsystem. A later patch in this series will use these functions for
carrying forward the IMA measurement log for ARM64.

With the above refactoring arch/powerpc/kexec/ima.c contains only
functions used when CONFIG_IMA_KEXEC is enabled. Update Makefile
in arch/powerpc/kexec to include arch/powerpc/kexec/ima.c only
when CONFIG_IMA_KEXEC is enabled.

Move ima_dump_measurement_list() and ima_add_kexec_buffer() to
a new file namely ima_kexec_fdt.c in IMA. Update
security/integrity/ima/Makefile to include ima_kexec_fdt.c only
when CONFIG_IMA_KEXEC is enabled.

Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
---
 arch/powerpc/include/asm/ima.h         |   3 -
 arch/powerpc/kexec/Makefile            |   7 +-
 arch/powerpc/kexec/ima.c               |  56 ---------
 security/integrity/ima/Makefile        |   1 +
 security/integrity/ima/ima_kexec.c     | 154 +++++++------------------
 security/integrity/ima/ima_kexec_fdt.c | 136 ++++++++++++++++++++++
 6 files changed, 182 insertions(+), 175 deletions(-)
 create mode 100644 security/integrity/ima/ima_kexec_fdt.c

diff --git a/arch/powerpc/include/asm/ima.h b/arch/powerpc/include/asm/ima.h
index 6355a85a3289..8975f5e0cab8 100644
--- a/arch/powerpc/include/asm/ima.h
+++ b/arch/powerpc/include/asm/ima.h
@@ -6,9 +6,6 @@
 
 struct kimage;
 
-int ima_get_kexec_buffer(void **addr, size_t *size);
-int ima_free_kexec_buffer(void);
-
 #ifdef CONFIG_IMA_KEXEC
 int arch_ima_add_kexec_buffer(struct kimage *image, unsigned long load_addr,
 			      size_t size);
diff --git a/arch/powerpc/kexec/Makefile b/arch/powerpc/kexec/Makefile
index 4aff6846c772..f54a9dbff4c8 100644
--- a/arch/powerpc/kexec/Makefile
+++ b/arch/powerpc/kexec/Makefile
@@ -9,12 +9,7 @@ obj-$(CONFIG_PPC32)		+= relocate_32.o
 
 obj-$(CONFIG_KEXEC_FILE)	+= file_load.o ranges.o file_load_$(BITS).o elf_$(BITS).o
 
-ifdef CONFIG_HAVE_IMA_KEXEC
-ifdef CONFIG_IMA
-obj-y				+= ima.o
-endif
-endif
-
+obj-$(CONFIG_IMA_KEXEC)		+= ima.o
 
 # Disable GCOV, KCOV & sanitizers in odd or sensitive code
 GCOV_PROFILE_core_$(BITS).o := n
diff --git a/arch/powerpc/kexec/ima.c b/arch/powerpc/kexec/ima.c
index 2b790230ea15..4fadd8d16891 100644
--- a/arch/powerpc/kexec/ima.c
+++ b/arch/powerpc/kexec/ima.c
@@ -30,61 +30,6 @@ static int get_addr_size_cells(int *addr_cells, int *size_cells)
 	return 0;
 }
 
-/**
- * ima_get_kexec_buffer - get IMA buffer from the previous kernel
- * @addr:	On successful return, set to point to the buffer contents.
- * @size:	On successful return, set to the buffer size.
- *
- * Return: 0 on success, negative errno on error.
- */
-int ima_get_kexec_buffer(void **addr, size_t *size)
-{
-	int ret, len;
-	unsigned long tmp_addr;
-	size_t tmp_size;
-	const void *prop;
-
-	prop = of_get_property(of_chosen, "linux,ima-kexec-buffer", &len);
-	if (!prop)
-		return -ENOENT;
-
-	ret = do_get_kexec_buffer(prop, len, &tmp_addr, &tmp_size);
-	if (ret)
-		return ret;
-
-	*addr = __va(tmp_addr);
-	*size = tmp_size;
-
-	return 0;
-}
-
-/**
- * ima_free_kexec_buffer - free memory used by the IMA buffer
- */
-int ima_free_kexec_buffer(void)
-{
-	int ret;
-	unsigned long addr;
-	size_t size;
-	struct property *prop;
-
-	prop = of_find_property(of_chosen, "linux,ima-kexec-buffer", NULL);
-	if (!prop)
-		return -ENOENT;
-
-	ret = do_get_kexec_buffer(prop->value, prop->length, &addr, &size);
-	if (ret)
-		return ret;
-
-	ret = of_remove_property(of_chosen, prop);
-	if (ret)
-		return ret;
-
-	return memblock_free(addr, size);
-
-}
-
-#ifdef CONFIG_IMA_KEXEC
 /**
  * arch_ima_add_kexec_buffer - do arch-specific steps to add the IMA buffer
  *
@@ -177,4 +122,3 @@ int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node)
 
 	return 0;
 }
-#endif /* CONFIG_IMA_KEXEC */
diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
index 67dabca670e2..0c440870a4e9 100644
--- a/security/integrity/ima/Makefile
+++ b/security/integrity/ima/Makefile
@@ -14,3 +14,4 @@ ima-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o
 ima-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o
 ima-$(CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS) += ima_asymmetric_keys.o
 ima-$(CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS) += ima_queue_keys.o
+ima-$(CONFIG_IMA_KEXEC) += ima_kexec_fdt.o
diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c
index 121de3e04af2..987e464be889 100644
--- a/security/integrity/ima/ima_kexec.c
+++ b/security/integrity/ima/ima_kexec.c
@@ -7,131 +7,65 @@
  * Mimi Zohar <zohar@linux.vnet.ibm.com>
  */
 
-#include <linux/seq_file.h>
 #include <linux/vmalloc.h>
 #include <linux/kexec.h>
+#include <linux/of.h>
+#include <linux/memblock.h>
+#include <linux/libfdt.h>
+#include <linux/ima.h>
 #include "ima.h"
 
-#ifdef CONFIG_IMA_KEXEC
-static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer,
-				     unsigned long segment_size)
+/**
+ * ima_get_kexec_buffer - get IMA buffer from the previous kernel
+ * @addr:	On successful return, set to point to the buffer contents.
+ * @size:	On successful return, set to the buffer size.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+static int ima_get_kexec_buffer(void **addr, size_t *size)
 {
-	struct ima_queue_entry *qe;
-	struct seq_file file;
-	struct ima_kexec_hdr khdr;
-	int ret = 0;
-
-	/* segment size can't change between kexec load and execute */
-	file.buf = vmalloc(segment_size);
-	if (!file.buf) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	file.size = segment_size;
-	file.read_pos = 0;
-	file.count = sizeof(khdr);	/* reserved space */
-
-	memset(&khdr, 0, sizeof(khdr));
-	khdr.version = 1;
-	list_for_each_entry_rcu(qe, &ima_measurements, later) {
-		if (file.count < file.size) {
-			khdr.count++;
-			ima_measurements_show(&file, qe);
-		} else {
-			ret = -EINVAL;
-			break;
-		}
-	}
-
-	if (ret < 0)
-		goto out;
-
-	/*
-	 * fill in reserved space with some buffer details
-	 * (eg. version, buffer size, number of measurements)
-	 */
-	khdr.buffer_size = file.count;
-	if (ima_canonical_fmt) {
-		khdr.version = cpu_to_le16(khdr.version);
-		khdr.count = cpu_to_le64(khdr.count);
-		khdr.buffer_size = cpu_to_le64(khdr.buffer_size);
-	}
-	memcpy(file.buf, &khdr, sizeof(khdr));
-
-	print_hex_dump(KERN_DEBUG, "ima dump: ", DUMP_PREFIX_NONE,
-			16, 1, file.buf,
-			file.count < 100 ? file.count : 100, true);
-
-	*buffer_size = file.count;
-	*buffer = file.buf;
-out:
-	if (ret == -EINVAL)
-		vfree(file.buf);
-	return ret;
+	int ret, len;
+	unsigned long tmp_addr;
+	size_t tmp_size;
+	const void *prop;
+
+	prop = of_get_property(of_chosen, FDT_PROP_IMA_KEXEC_BUFFER, &len);
+	if (!prop)
+		return -ENOENT;
+
+	ret = do_get_kexec_buffer(prop, len, &tmp_addr, &tmp_size);
+	if (ret)
+		return ret;
+
+	*addr = __va(tmp_addr);
+	*size = tmp_size;
+	return 0;
 }
 
-/*
- * Called during kexec_file_load so that IMA can add a segment to the kexec
- * image for the measurement list for the next kernel.
- *
- * This function assumes that kexec_mutex is held.
+/**
+ * ima_free_kexec_buffer - free memory used by the IMA buffer
  */
-void ima_add_kexec_buffer(struct kimage *image)
+static int ima_free_kexec_buffer(void)
 {
-	struct kexec_buf kbuf = { .image = image, .buf_align = PAGE_SIZE,
-				  .buf_min = 0, .buf_max = ULONG_MAX,
-				  .top_down = true };
-	unsigned long binary_runtime_size;
-
-	/* use more understandable variable names than defined in kbuf */
-	void *kexec_buffer = NULL;
-	size_t kexec_buffer_size;
-	size_t kexec_segment_size;
 	int ret;
+	unsigned long addr;
+	size_t size;
+	struct property *prop;
 
-	/*
-	 * Reserve an extra half page of memory for additional measurements
-	 * added during the kexec load.
-	 */
-	binary_runtime_size = ima_get_binary_runtime_size();
-	if (binary_runtime_size >= ULONG_MAX - PAGE_SIZE)
-		kexec_segment_size = ULONG_MAX;
-	else
-		kexec_segment_size = ALIGN(ima_get_binary_runtime_size() +
-					   PAGE_SIZE / 2, PAGE_SIZE);
-	if ((kexec_segment_size == ULONG_MAX) ||
-	    ((kexec_segment_size >> PAGE_SHIFT) > totalram_pages() / 2)) {
-		pr_err("Binary measurement list too large.\n");
-		return;
-	}
+	prop = of_find_property(of_chosen, FDT_PROP_IMA_KEXEC_BUFFER, NULL);
+	if (!prop)
+		return -ENOENT;
 
-	ima_dump_measurement_list(&kexec_buffer_size, &kexec_buffer,
-				  kexec_segment_size);
-	if (!kexec_buffer) {
-		pr_err("Not enough memory for the kexec measurement buffer.\n");
-		return;
-	}
+	ret = do_get_kexec_buffer(prop->value, prop->length, &addr, &size);
+	if (ret)
+		return ret;
 
-	kbuf.buffer = kexec_buffer;
-	kbuf.bufsz = kexec_buffer_size;
-	kbuf.memsz = kexec_segment_size;
-	ret = kexec_add_buffer(&kbuf);
-	if (ret) {
-		pr_err("Error passing over kexec measurement buffer.\n");
-		return;
-	}
-
-	ret = arch_ima_add_kexec_buffer(image, kbuf.mem, kexec_segment_size);
-	if (ret) {
-		pr_err("Error passing over kexec measurement buffer.\n");
-		return;
-	}
+	ret = of_remove_property(of_chosen, prop);
+	if (ret)
+		return ret;
 
-	pr_debug("kexec measurement buffer for the loaded kernel at 0x%lx.\n",
-		 kbuf.mem);
+	return memblock_free(addr, size);
 }
-#endif /* IMA_KEXEC */
 
 /*
  * Restore the measurement list from the previous kernel.
diff --git a/security/integrity/ima/ima_kexec_fdt.c b/security/integrity/ima/ima_kexec_fdt.c
new file mode 100644
index 000000000000..186051467e5b
--- /dev/null
+++ b/security/integrity/ima/ima_kexec_fdt.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2016 IBM Corporation
+ *
+ * Authors:
+ * Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
+ * Mimi Zohar <zohar@linux.vnet.ibm.com>
+ */
+
+#include <linux/seq_file.h>
+#include <linux/vmalloc.h>
+#include <linux/kexec.h>
+#include <linux/of.h>
+#include <linux/memblock.h>
+#include <linux/libfdt.h>
+#include <linux/ima.h>
+#include "ima.h"
+
+static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer,
+				     unsigned long segment_size)
+{
+	struct ima_queue_entry *qe;
+	struct seq_file file;
+	struct ima_kexec_hdr khdr;
+	int ret = 0;
+
+	/* segment size can't change between kexec load and execute */
+	file.buf = vmalloc(segment_size);
+	if (!file.buf) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	file.size = segment_size;
+	file.read_pos = 0;
+	file.count = sizeof(khdr);	/* reserved space */
+
+	memset(&khdr, 0, sizeof(khdr));
+	khdr.version = 1;
+	list_for_each_entry_rcu(qe, &ima_measurements, later) {
+		if (file.count < file.size) {
+			khdr.count++;
+			ima_measurements_show(&file, qe);
+		} else {
+			ret = -EINVAL;
+			break;
+		}
+	}
+
+	if (ret < 0)
+		goto out;
+
+	/*
+	 * fill in reserved space with some buffer details
+	 * (eg. version, buffer size, number of measurements)
+	 */
+	khdr.buffer_size = file.count;
+	if (ima_canonical_fmt) {
+		khdr.version = cpu_to_le16(khdr.version);
+		khdr.count = cpu_to_le64(khdr.count);
+		khdr.buffer_size = cpu_to_le64(khdr.buffer_size);
+	}
+	memcpy(file.buf, &khdr, sizeof(khdr));
+
+	print_hex_dump(KERN_DEBUG, "ima dump: ", DUMP_PREFIX_NONE,
+			16, 1, file.buf,
+			file.count < 100 ? file.count : 100, true);
+
+	*buffer_size = file.count;
+	*buffer = file.buf;
+out:
+	if (ret == -EINVAL)
+		vfree(file.buf);
+	return ret;
+}
+
+/*
+ * Called during kexec_file_load so that IMA can add a segment to the kexec
+ * image for the measurement list for the next kernel.
+ *
+ * This function assumes that kexec_mutex is held.
+ */
+void ima_add_kexec_buffer(struct kimage *image)
+{
+	struct kexec_buf kbuf = { .image = image, .buf_align = PAGE_SIZE,
+				  .buf_min = 0, .buf_max = ULONG_MAX,
+				  .top_down = true };
+	unsigned long binary_runtime_size;
+
+	/* use more understandable variable names than defined in kbuf */
+	void *kexec_buffer = NULL;
+	size_t kexec_buffer_size;
+	size_t kexec_segment_size;
+	int ret;
+
+	/*
+	 * Reserve an extra half page of memory for additional measurements
+	 * added during the kexec load.
+	 */
+	binary_runtime_size = ima_get_binary_runtime_size();
+	if (binary_runtime_size >= ULONG_MAX - PAGE_SIZE)
+		kexec_segment_size = ULONG_MAX;
+	else
+		kexec_segment_size = ALIGN(ima_get_binary_runtime_size() +
+					   PAGE_SIZE / 2, PAGE_SIZE);
+	if ((kexec_segment_size == ULONG_MAX) ||
+	    ((kexec_segment_size >> PAGE_SHIFT) > totalram_pages() / 2)) {
+		pr_err("Binary measurement list too large.\n");
+		return;
+	}
+
+	ima_dump_measurement_list(&kexec_buffer_size, &kexec_buffer,
+				  kexec_segment_size);
+	if (!kexec_buffer) {
+		pr_err("Not enough memory for the kexec measurement buffer.\n");
+		return;
+	}
+
+	kbuf.buffer = kexec_buffer;
+	kbuf.bufsz = kexec_buffer_size;
+	kbuf.memsz = kexec_segment_size;
+	ret = kexec_add_buffer(&kbuf);
+	if (ret) {
+		pr_err("Error passing over kexec measurement buffer.\n");
+		return;
+	}
+
+	ret = arch_ima_add_kexec_buffer(image, kbuf.mem, kexec_segment_size);
+	if (ret) {
+		pr_err("Error passing over kexec measurement buffer.\n");
+		return;
+	}
+
+	pr_debug("kexec measurement buffer for the loaded kernel at 0x%lx.\n",
+		 kbuf.mem);
+}
-- 
2.28.0

[PATCH v7 3/4] arm64: Store IMA log information in kimage used for kexec

[Lakshmi Ramasubramanian]

Address and size of the buffer containing the IMA measurement log need
to be passed from the current kernel to the next kernel on kexec.

Add address and size fields to "struct kimage_arch" for ARM64 platform
to hold the address and size of the IMA measurement log buffer.
Define an architecture specific function for ARM64 namely
arch_ima_add_kexec_buffer() that will set the address and size of
the current kernel's IMA buffer to be passed to the next kernel on kexec.

Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
---
 arch/arm64/include/asm/ima.h   | 18 ++++++++++++++++++
 arch/arm64/include/asm/kexec.h |  3 +++
 arch/arm64/kernel/Makefile     |  1 +
 arch/arm64/kernel/ima_kexec.c  | 34 ++++++++++++++++++++++++++++++++++
 4 files changed, 56 insertions(+)
 create mode 100644 arch/arm64/include/asm/ima.h
 create mode 100644 arch/arm64/kernel/ima_kexec.c

diff --git a/arch/arm64/include/asm/ima.h b/arch/arm64/include/asm/ima.h
new file mode 100644
index 000000000000..507fc94ddaba
--- /dev/null
+++ b/arch/arm64/include/asm/ima.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2019 Microsoft Corporation
+ *
+ * Author: Prakhar Srivastava <prsriva@linux.microsoft.com>
+ *
+ */
+#ifndef _ASM_ARCH_IMA_H
+#define _ASM_ARCH_IMA_H
+
+struct kimage;
+
+#ifdef CONFIG_IMA_KEXEC
+int arch_ima_add_kexec_buffer(struct kimage *image, unsigned long load_addr,
+			      size_t size);
+#endif /* CONFIG_IMA_KEXEC */
+
+#endif /* _ASM_ARCH_IMA_H */
diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
index d24b527e8c00..7bd60c185ad3 100644
--- a/arch/arm64/include/asm/kexec.h
+++ b/arch/arm64/include/asm/kexec.h
@@ -100,6 +100,9 @@ struct kimage_arch {
 	void *elf_headers;
 	unsigned long elf_headers_mem;
 	unsigned long elf_headers_sz;
+
+	phys_addr_t ima_buffer_addr;
+	size_t ima_buffer_size;
 };
 
 extern const struct kexec_file_ops kexec_image_ops;
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index a561cbb91d4d..39c5d99b49fc 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -62,6 +62,7 @@ obj-$(CONFIG_ARM_SDE_INTERFACE)		+= sdei.o
 obj-$(CONFIG_ARM64_SSBD)		+= ssbd.o
 obj-$(CONFIG_ARM64_PTR_AUTH)		+= pointer_auth.o
 obj-$(CONFIG_SHADOW_CALL_STACK)		+= scs.o
+obj-$(CONFIG_IMA_KEXEC)			+= ima_kexec.o
 
 obj-y					+= vdso/ probes/
 obj-$(CONFIG_COMPAT_VDSO)		+= vdso32/
diff --git a/arch/arm64/kernel/ima_kexec.c b/arch/arm64/kernel/ima_kexec.c
new file mode 100644
index 000000000000..1847f1230710
--- /dev/null
+++ b/arch/arm64/kernel/ima_kexec.c
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2019 Microsoft Corporation
+ *
+ * Author: Prakhar Srivastava <prsriva@linux.microsoft.com>
+ *
+ * File: ima_kexec.c
+ *       Defines IMA kexec functions.
+ */
+
+#include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <linux/types.h>
+#include <asm/ima.h>
+
+/**
+ * arch_ima_add_kexec_buffer - do arch-specific steps to add the IMA buffer
+ *
+ * @image: kimage structure to set ima buffer information in for kexec
+ * @load_addr: Start address of the IMA buffer
+ * @size: size of the IMA buffer
+ *
+ * Architectures should use this function to pass on the IMA buffer
+ * information to the next kernel.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int arch_ima_add_kexec_buffer(struct kimage *image, unsigned long load_addr,
+			      size_t size)
+{
+	image->arch.ima_buffer_addr = load_addr;
+	image->arch.ima_buffer_size = size;
+	return 0;
+}
-- 
2.28.0

[PATCH v7 4/4] arm64: Add IMA kexec buffer to DTB

[Lakshmi Ramasubramanian]

Any existing FDT_PROP_IMA_KEXEC_BUFFER property in the device tree
needs to be removed and its corresponding memory reservation in
the currently running kernel needs to be freed.

The address and size of the current kernel's IMA measurement log need
to be added to the device tree's IMA kexec buffer node and memory for
the buffer needs to be reserved for the log to be carried over to
the next kernel on the kexec call.

Remove any existing FDT_PROP_IMA_KEXEC_BUFFER property in the device
tree and free the corresponding memory reservation in the currently
running kernel. Add FDT_PROP_IMA_KEXEC_BUFFER property to the device
tree and reserve the memory for storing the IMA log that needs to be
passed from the current kernel to the next one.

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

Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
---
 arch/arm64/Kconfig                     |  1 +
 arch/arm64/kernel/machine_kexec_file.c | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 6d232837cbee..9f03c8245e5b 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1077,6 +1077,7 @@ config KEXEC
 config KEXEC_FILE
 	bool "kexec file based system call"
 	select KEXEC_CORE
+	select HAVE_IMA_KEXEC
 	help
 	  This is new version of kexec system call. This system call is
 	  file based and takes file descriptors as system call argument
diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
index 361a1143e09e..e9a02e551bca 100644
--- a/arch/arm64/kernel/machine_kexec_file.c
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -21,6 +21,7 @@
 #include <linux/string.h>
 #include <linux/types.h>
 #include <linux/vmalloc.h>
+#include <linux/ima.h>
 #include <asm/byteorder.h>
 
 /* relevant device tree properties */
@@ -62,6 +63,8 @@ static int setup_dtb(struct kimage *image,
 
 	off = ret;
 
+	remove_ima_kexec_buffer(dtb, ret);
+
 	ret = fdt_delprop(dtb, off, FDT_PROP_KEXEC_ELFHDR);
 	if (ret && ret != -FDT_ERR_NOTFOUND)
 		goto out;
@@ -136,6 +139,21 @@ static int setup_dtb(struct kimage *image,
 				FDT_PROP_KASLR_SEED);
 	}
 
+	/* add ima-kexec-buffer */
+	if (image->arch.ima_buffer_size > 0) {
+		ret = fdt_appendprop_addrrange(dtb, 0, off,
+				FDT_PROP_IMA_KEXEC_BUFFER,
+				image->arch.ima_buffer_addr,
+				image->arch.ima_buffer_size);
+		if (ret)
+			return (ret == -FDT_ERR_NOSPACE ? -ENOMEM : -EINVAL);
+
+		ret = fdt_add_mem_rsv(dtb, image->arch.ima_buffer_addr,
+				      image->arch.ima_buffer_size);
+		if (ret)
+			goto out;
+	}
+
 	/* add rng-seed */
 	if (rng_is_initialized()) {
 		void *rng_seed;
-- 
2.28.0

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

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 2985 bytes --]

Hi Lakshmi,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on powerpc/next]
[also build test ERROR on arm64/for-next/core integrity/next-integrity linus/master v5.9-rc7 next-20200930]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Lakshmi-Ramasubramanian/powerpc-Refactor-kexec-functions-to-move-arch-independent-code-to-kernel/20201001-060013
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: parisc-randconfig-r012-20200930 (attached as .config)
compiler: hppa-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/6a1d11b4c60a9d19172f2aee98568c0ce65da4ea
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Lakshmi-Ramasubramanian/powerpc-Refactor-kexec-functions-to-move-arch-independent-code-to-kernel/20201001-060013
        git checkout 6a1d11b4c60a9d19172f2aee98568c0ce65da4ea
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=parisc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   hppa-linux-ld: kernel/kexec_file_fdt.o: in function `delete_fdt_mem_rsv':
>> kernel/kexec_file_fdt.c:30: undefined reference to `fdt_num_mem_rsv'
>> hppa-linux-ld: kernel/kexec_file_fdt.c:35: undefined reference to `fdt_get_mem_rsv'
>> hppa-linux-ld: kernel/kexec_file_fdt.c:42: undefined reference to `fdt_del_mem_rsv'

vim +30 kernel/kexec_file_fdt.c

    18	
    19	/**
    20	 * delete_fdt_mem_rsv - delete memory reservation with given address and size
    21	 *
    22	 * @fdt: Flattened Device Tree to update
    23	 * @start: Starting address of the reservation to delete
    24	 * @size: Size of the reservation to delete
    25	 *
    26	 * Return: 0 on success, or negative errno on error.
    27	 */
    28	int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size)
    29	{
  > 30		int i, ret, num_rsvs = fdt_num_mem_rsv(fdt);
    31	
    32		for (i = 0; i < num_rsvs; i++) {
    33			uint64_t rsv_start, rsv_size;
    34	
  > 35			ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
    36			if (ret) {
    37				pr_err("Malformed device tree.\n");
    38				return -EINVAL;
    39			}
    40	
    41			if (rsv_start == start && rsv_size == size) {
  > 42				ret = fdt_del_mem_rsv(fdt, i);

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 26079 bytes --]

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

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 1943 bytes --]

Hi Lakshmi,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on powerpc/next]
[also build test ERROR on arm64/for-next/core integrity/next-integrity linus/master v5.9-rc7 next-20200930]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Lakshmi-Ramasubramanian/powerpc-Refactor-kexec-functions-to-move-arch-independent-code-to-kernel/20201001-060013
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: x86_64-randconfig-s022-20200930 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.2-201-g24bdaac6-dirty
        # https://github.com/0day-ci/linux/commit/6a1d11b4c60a9d19172f2aee98568c0ce65da4ea
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Lakshmi-Ramasubramanian/powerpc-Refactor-kexec-functions-to-move-arch-independent-code-to-kernel/20201001-060013
        git checkout 6a1d11b4c60a9d19172f2aee98568c0ce65da4ea
        # save the attached .config to linux build tree
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   ld: kernel/kexec_file_fdt.o: in function `delete_fdt_mem_rsv':
   kernel/kexec_file_fdt.c:30: undefined reference to `fdt_num_mem_rsv'
>> ld: kernel/kexec_file_fdt.c:35: undefined reference to `fdt_get_mem_rsv'
>> ld: kernel/kexec_file_fdt.c:42: undefined reference to `fdt_del_mem_rsv'

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 32756 bytes --]

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

[Mimi Zohar]

Hi Lakshmi,

On Wed, 2020-09-30 at 13:59 -0700, Lakshmi Ramasubramanian wrote:
> The functions remove_ima_buffer() and delete_fdt_mem_rsv() that handle
> carrying forward the IMA measurement logs on kexec for powerpc do not
> have architecture specific code, but they are currently defined for
> powerpc only.
> 
> remove_ima_buffer() and delete_fdt_mem_rsv() are used to remove
> the IMA log entry from the device tree and free the memory reserved
> for the log. These functions need to be defined even if the current
> kernel does not support carrying forward IMA log across kexec since
> the previous kernel could have supported that and therefore the current
> kernel needs to free the allocation.
> 
> Rename remove_ima_buffer() to remove_ima_kexec_buffer().
> Define remove_ima_kexec_buffer() and delete_fdt_mem_rsv() in kernel.
> A later patch in this series will use these functions to free
> the allocation, if any, made by the previous kernel for ARM64.
> 
> Define FDT_PROP_IMA_KEXEC_BUFFER for the chosen node, namely
> "linux,ima-kexec-buffer", that is added to the DTB to hold
> the address and the size of the memory reserved to carry
> the IMA measurement log.

> Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
> Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
> Reported-by: kernel test robot <lkp@intel.com> error: implicit declaration of function 'delete_fdt_mem_rsv' [-Werror,-Wimplicit-function-declaration]

Much better!  This version limits unnecessarily changing the existing
code to adding a couple of debugging statements, but that looks to be
about it.

Based on Chester Lin's "ima_arch" support for arm64 discussion, the IMA generic
EFI support will be defined in ima/ima-efi.c.  Similarly, I think it would make sense to put the generic device tree support in ima/ima_kexec_fdt.c or ima/ima_fdt.c, as opposed to kernel/.  (Refer to my comments on 2/4 about the new file named ima_kexec_fdt.c.)

thanks,

Mimi

Re: [PATCH v7 2/4] powerpc: Refactor kexec functions to move arch independent code to ima

[Mimi Zohar]

On Wed, 2020-09-30 at 13:59 -0700, Lakshmi Ramasubramanian wrote:
> The functions ima_get_kexec_buffer() and ima_free_kexec_buffer(),
> that handle carrying forward the IMA measurement logs on kexec for
> powerpc do not have architecture specific code, but they are currently
> defined for powerpc only.
> 
> Move ima_get_kexec_buffer() and ima_free_kexec_buffer() to IMA
> subsystem. A later patch in this series will use these functions for
> carrying forward the IMA measurement log for ARM64.
> 
> With the above refactoring arch/powerpc/kexec/ima.c contains only
> functions used when CONFIG_IMA_KEXEC is enabled. Update Makefile
> in arch/powerpc/kexec to include arch/powerpc/kexec/ima.c only
> when CONFIG_IMA_KEXEC is enabled.
> 
> Move ima_dump_measurement_list() and ima_add_kexec_buffer() to
> a new file namely ima_kexec_fdt.c in IMA. Update
> security/integrity/ima/Makefile to include ima_kexec_fdt.c only
> when CONFIG_IMA_KEXEC is enabled.
> 
> Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
> Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>

The existing support for carrying the IMA measurement list across kexec
is limited to powerpc.  This patch set is adding similar support for
arm64, making as much of the existing code as generic as possible. 
However ima_dump_measurement_list() is already generic, but for some
reason this patch moves it to ima_kexec_fdt.c.  ima_kexec_fdt.c should
be limited to device tree specific code.

This patch is probably doing the right thing, but the way the patch is
formatted it replaces parts of a function with a different function. 
With the changes suggested above and in 1/4,  the next version should
be clearer.

thanks,

Mimi

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

[Lakshmi Ramasubramanian]

On 10/20/20 1:00 PM, Mimi Zohar wrote:
> Hi Lakshmi,
> 
> On Wed, 2020-09-30 at 13:59 -0700, Lakshmi Ramasubramanian wrote:
>> The functions remove_ima_buffer() and delete_fdt_mem_rsv() that handle
>> carrying forward the IMA measurement logs on kexec for powerpc do not
>> have architecture specific code, but they are currently defined for
>> powerpc only.
>>
>> remove_ima_buffer() and delete_fdt_mem_rsv() are used to remove
>> the IMA log entry from the device tree and free the memory reserved
>> for the log. These functions need to be defined even if the current
>> kernel does not support carrying forward IMA log across kexec since
>> the previous kernel could have supported that and therefore the current
>> kernel needs to free the allocation.
>>
>> Rename remove_ima_buffer() to remove_ima_kexec_buffer().
>> Define remove_ima_kexec_buffer() and delete_fdt_mem_rsv() in kernel.
>> A later patch in this series will use these functions to free
>> the allocation, if any, made by the previous kernel for ARM64.
>>
>> Define FDT_PROP_IMA_KEXEC_BUFFER for the chosen node, namely
>> "linux,ima-kexec-buffer", that is added to the DTB to hold
>> the address and the size of the memory reserved to carry
>> the IMA measurement log.
> 
>> Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
>> Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
>> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
>> Reported-by: kernel test robot <lkp@intel.com> error: implicit declaration of function 'delete_fdt_mem_rsv' [-Werror,-Wimplicit-function-declaration]
> 
> Much better!  This version limits unnecessarily changing the existing
> code to adding a couple of debugging statements, but that looks to be
> about it.
Yes Mimi - that's correct.

> 
> Based on Chester Lin's "ima_arch" support for arm64 discussion, the IMA generic
> EFI support will be defined in ima/ima-efi.c.  Similarly, I think it would make sense to put the generic device tree support in ima/ima_kexec_fdt.c or ima/ima_fdt.c, as opposed to kernel/.  (Refer to my comments on 2/4 about the new file named ima_kexec_fdt.c.)

The functions remove_ima_kexec_buffer() and delete_fdt_mem_rsv(), which 
are defined in kernel/ima_kexec.c and kernel/kexec_file_fdt.c 
respectively, are needed even when CONFIG_IMA is not defined. These 
functions need to be called by the current kernel to free the ima kexec 
buffer resources allocated by the previous kernel. This is the reason, 
these functions are defined under "kernel" instead of 
"security/integrity/ima".

If there is a better location to move the above C files, please let me 
know. I'll move them.

thanks,
  -lakshmi

Re: [PATCH v7 2/4] powerpc: Refactor kexec functions to move arch independent code to ima

[Lakshmi Ramasubramanian]

On 10/20/20 1:01 PM, Mimi Zohar wrote:
> On Wed, 2020-09-30 at 13:59 -0700, Lakshmi Ramasubramanian wrote:
>> The functions ima_get_kexec_buffer() and ima_free_kexec_buffer(),
>> that handle carrying forward the IMA measurement logs on kexec for
>> powerpc do not have architecture specific code, but they are currently
>> defined for powerpc only.
>>
>> Move ima_get_kexec_buffer() and ima_free_kexec_buffer() to IMA
>> subsystem. A later patch in this series will use these functions for
>> carrying forward the IMA measurement log for ARM64.
>>
>> With the above refactoring arch/powerpc/kexec/ima.c contains only
>> functions used when CONFIG_IMA_KEXEC is enabled. Update Makefile
>> in arch/powerpc/kexec to include arch/powerpc/kexec/ima.c only
>> when CONFIG_IMA_KEXEC is enabled.
>>
>> Move ima_dump_measurement_list() and ima_add_kexec_buffer() to
>> a new file namely ima_kexec_fdt.c in IMA. Update
>> security/integrity/ima/Makefile to include ima_kexec_fdt.c only
>> when CONFIG_IMA_KEXEC is enabled.
>>
>> Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
>> Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
>> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
> 
> The existing support for carrying the IMA measurement list across kexec
> is limited to powerpc.  This patch set is adding similar support for
> arm64, making as much of the existing code as generic as possible.
> However ima_dump_measurement_list() is already generic, but for some
> reason this patch moves it to ima_kexec_fdt.c.  ima_kexec_fdt.c should
> be limited to device tree specific code.

I wanted to split the functions defined under CONFIG_HAVE_IMA_KEXEC and 
CONFIG_IMA_KEXEC to separate files so that we can get rid of #ifdef in C 
file and instead conditionally compile the C files (using Makefile).

ima_dump_measurement_list() need to be defined only when 
CONFIG_IMA_KEXEC is defined. I moved it to ima_kexec_fdt.c

Instead of ima_kexec_fdt.c, where ima_dump_measurement_list() and 
ima_add_kexec_buffer() are defined, perhaps I can change the file name 
to "ima_kexec_buffer.c". Would that be better?

> 
> This patch is probably doing the right thing, but the way the patch is
> formatted it replaces parts of a function with a different function.
> With the changes suggested above and in 1/4,  the next version should
> be clearer.

Like I'd stated above, I wanted to remove "#ifdef" from the C files and 
hence had to move some functions. But the functionalities haven't been 
changed.

thanks,
  -lakshmi

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

[Mimi Zohar]

On Tue, 2020-10-20 at 19:25 -0700, Lakshmi Ramasubramanian wrote:
> On 10/20/20 1:00 PM, Mimi Zohar wrote:
> > Hi Lakshmi,
> > 
> > On Wed, 2020-09-30 at 13:59 -0700, Lakshmi Ramasubramanian wrote:
> >> The functions remove_ima_buffer() and delete_fdt_mem_rsv() that handle
> >> carrying forward the IMA measurement logs on kexec for powerpc do not
> >> have architecture specific code, but they are currently defined for
> >> powerpc only.
> >>
> >> remove_ima_buffer() and delete_fdt_mem_rsv() are used to remove
> >> the IMA log entry from the device tree and free the memory reserved
> >> for the log. These functions need to be defined even if the current
> >> kernel does not support carrying forward IMA log across kexec since
> >> the previous kernel could have supported that and therefore the current
> >> kernel needs to free the allocation.
> >>
> >> Rename remove_ima_buffer() to remove_ima_kexec_buffer().
> >> Define remove_ima_kexec_buffer() and delete_fdt_mem_rsv() in kernel.
> >> A later patch in this series will use these functions to free
> >> the allocation, if any, made by the previous kernel for ARM64.
> >>
> >> Define FDT_PROP_IMA_KEXEC_BUFFER for the chosen node, namely
> >> "linux,ima-kexec-buffer", that is added to the DTB to hold
> >> the address and the size of the memory reserved to carry
> >> the IMA measurement log.
> > 
> >> Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
> >> Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
> >> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
> >> Reported-by: kernel test robot <lkp@intel.com> error: implicit declaration of function 'delete_fdt_mem_rsv' [-Werror,-Wimplicit-function-declaration]
> > 
> > Much better!  This version limits unnecessarily changing the existing
> > code to adding a couple of debugging statements, but that looks to be
> > about it.
> Yes Mimi - that's correct.
> 
> > 
> > Based on Chester Lin's "ima_arch" support for arm64 discussion, the IMA generic
> > EFI support will be defined in ima/ima-efi.c.  Similarly, I think it would make sense to put the generic device tree support in ima/ima_kexec_fdt.c or ima/ima_fdt.c, as opposed to kernel/.  (Refer to my comments on 2/4 about the new file named ima_kexec_fdt.c.)
> 
> The functions remove_ima_kexec_buffer() and delete_fdt_mem_rsv(), which 
> are defined in kernel/ima_kexec.c and kernel/kexec_file_fdt.c 
> respectively, are needed even when CONFIG_IMA is not defined. These 
> functions need to be called by the current kernel to free the ima kexec 
> buffer resources allocated by the previous kernel. This is the reason, 
> these functions are defined under "kernel" instead of 
> "security/integrity/ima".
> 
> If there is a better location to move the above C files, please let me 
> know. I'll move them.

Freeing the previous kernel measurement list is currently called from
ima_load_kexec_buffer(), only after the measurement list has been
restored.  The only other time the memory is freed is when the
allocated memory size isn't sufficient to hold the measurement list,
which could happen if there is a delay between loading and executing
the kexec.

thanks,

Mimi

Re: [PATCH v7 2/4] powerpc: Refactor kexec functions to move arch independent code to ima

[Mimi Zohar]

Hi Lakshmi,

On Tue, 2020-10-20 at 19:38 -0700, Lakshmi Ramasubramanian wrote:
> On 10/20/20 1:01 PM, Mimi Zohar wrote:
> > On Wed, 2020-09-30 at 13:59 -0700, Lakshmi Ramasubramanian wrote:
> >> The functions ima_get_kexec_buffer() and ima_free_kexec_buffer(),
> >> that handle carrying forward the IMA measurement logs on kexec for
> >> powerpc do not have architecture specific code, but they are currently
> >> defined for powerpc only.
> >>
> >> Move ima_get_kexec_buffer() and ima_free_kexec_buffer() to IMA
> >> subsystem. A later patch in this series will use these functions for
> >> carrying forward the IMA measurement log for ARM64.
> >>
> >> With the above refactoring arch/powerpc/kexec/ima.c contains only
> >> functions used when CONFIG_IMA_KEXEC is enabled. Update Makefile
> >> in arch/powerpc/kexec to include arch/powerpc/kexec/ima.c only
> >> when CONFIG_IMA_KEXEC is enabled.
> >>
> >> Move ima_dump_measurement_list() and ima_add_kexec_buffer() to
> >> a new file namely ima_kexec_fdt.c in IMA. Update
> >> security/integrity/ima/Makefile to include ima_kexec_fdt.c only
> >> when CONFIG_IMA_KEXEC is enabled.
> >>
> >> Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
> >> Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
> >> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
> > 
> > The existing support for carrying the IMA measurement list across kexec
> > is limited to powerpc.  This patch set is adding similar support for
> > arm64, making as much of the existing code as generic as possible.
> > However ima_dump_measurement_list() is already generic, but for some
> > reason this patch moves it to ima_kexec_fdt.c.  ima_kexec_fdt.c should
> > be limited to device tree specific code.
> 
> I wanted to split the functions defined under CONFIG_HAVE_IMA_KEXEC and 
> CONFIG_IMA_KEXEC to separate files so that we can get rid of #ifdef in C 
> file and instead conditionally compile the C files (using Makefile).
> 
> ima_dump_measurement_list() need to be defined only when 
> CONFIG_IMA_KEXEC is defined. I moved it to ima_kexec_fdt.c

In this case, everything in ima_kexec.c relates to carrying or
restoring the measurement list.  It's a logical unit.  Separating them
doesn't make sense.

> 
> Instead of ima_kexec_fdt.c, where ima_dump_measurement_list() and 
> ima_add_kexec_buffer() are defined, perhaps I can change the file name 
> to "ima_kexec_buffer.c". Would that be better?

I don't understand why adding support for carrying the IMA measurement
across kexec on ARM64, should require any changes in the IMA loading
and restoring the measurement list code itself.  Please minimize the
changes.

thanks,

Mimi

Re: [PATCH v7 2/4] powerpc: Refactor kexec functions to move arch independent code to ima

[Lakshmi Ramasubramanian]

On 10/20/20 8:50 PM, Mimi Zohar wrote:
> Hi Lakshmi,
> 
> On Tue, 2020-10-20 at 19:38 -0700, Lakshmi Ramasubramanian wrote:
>> On 10/20/20 1:01 PM, Mimi Zohar wrote:
>>> On Wed, 2020-09-30 at 13:59 -0700, Lakshmi Ramasubramanian wrote:
>>>> The functions ima_get_kexec_buffer() and ima_free_kexec_buffer(),
>>>> that handle carrying forward the IMA measurement logs on kexec for
>>>> powerpc do not have architecture specific code, but they are currently
>>>> defined for powerpc only.
>>>>
>>>> Move ima_get_kexec_buffer() and ima_free_kexec_buffer() to IMA
>>>> subsystem. A later patch in this series will use these functions for
>>>> carrying forward the IMA measurement log for ARM64.
>>>>
>>>> With the above refactoring arch/powerpc/kexec/ima.c contains only
>>>> functions used when CONFIG_IMA_KEXEC is enabled. Update Makefile
>>>> in arch/powerpc/kexec to include arch/powerpc/kexec/ima.c only
>>>> when CONFIG_IMA_KEXEC is enabled.
>>>>
>>>> Move ima_dump_measurement_list() and ima_add_kexec_buffer() to
>>>> a new file namely ima_kexec_fdt.c in IMA. Update
>>>> security/integrity/ima/Makefile to include ima_kexec_fdt.c only
>>>> when CONFIG_IMA_KEXEC is enabled.
>>>>
>>>> Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
>>>> Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
>>>> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
>>>
>>> The existing support for carrying the IMA measurement list across kexec
>>> is limited to powerpc.  This patch set is adding similar support for
>>> arm64, making as much of the existing code as generic as possible.
>>> However ima_dump_measurement_list() is already generic, but for some
>>> reason this patch moves it to ima_kexec_fdt.c.  ima_kexec_fdt.c should
>>> be limited to device tree specific code.
>>
>> I wanted to split the functions defined under CONFIG_HAVE_IMA_KEXEC and
>> CONFIG_IMA_KEXEC to separate files so that we can get rid of #ifdef in C
>> file and instead conditionally compile the C files (using Makefile).
>>
>> ima_dump_measurement_list() need to be defined only when
>> CONFIG_IMA_KEXEC is defined. I moved it to ima_kexec_fdt.c
> 
> In this case, everything in ima_kexec.c relates to carrying or
> restoring the measurement list.  It's a logical unit.  Separating them
> doesn't make sense.
> 

Sounds good - I'll keep ima_dump_measurement_list() and 
ima_add_kexec_buffer() in ima_kexec.c as it was earlier.

>>
>> Instead of ima_kexec_fdt.c, where ima_dump_measurement_list() and
>> ima_add_kexec_buffer() are defined, perhaps I can change the file name
>> to "ima_kexec_buffer.c". Would that be better?
> 
> I don't understand why adding support for carrying the IMA measurement
> across kexec on ARM64, should require any changes in the IMA loading
> and restoring the measurement list code itself.  Please minimize the
> changes.

Agreed - will do.

thanks,
  -lakshmi

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

[Lakshmi Ramasubramanian]

On 10/20/20 8:17 PM, Mimi Zohar wrote:
> On Tue, 2020-10-20 at 19:25 -0700, Lakshmi Ramasubramanian wrote:
>> On 10/20/20 1:00 PM, Mimi Zohar wrote:
>>> Hi Lakshmi,
>>>
>>> On Wed, 2020-09-30 at 13:59 -0700, Lakshmi Ramasubramanian wrote:
>>>> The functions remove_ima_buffer() and delete_fdt_mem_rsv() that handle
>>>> carrying forward the IMA measurement logs on kexec for powerpc do not
>>>> have architecture specific code, but they are currently defined for
>>>> powerpc only.
>>>>
>>>> remove_ima_buffer() and delete_fdt_mem_rsv() are used to remove
>>>> the IMA log entry from the device tree and free the memory reserved
>>>> for the log. These functions need to be defined even if the current
>>>> kernel does not support carrying forward IMA log across kexec since
>>>> the previous kernel could have supported that and therefore the current
>>>> kernel needs to free the allocation.
>>>>
>>>> Rename remove_ima_buffer() to remove_ima_kexec_buffer().
>>>> Define remove_ima_kexec_buffer() and delete_fdt_mem_rsv() in kernel.
>>>> A later patch in this series will use these functions to free
>>>> the allocation, if any, made by the previous kernel for ARM64.
>>>>
>>>> Define FDT_PROP_IMA_KEXEC_BUFFER for the chosen node, namely
>>>> "linux,ima-kexec-buffer", that is added to the DTB to hold
>>>> the address and the size of the memory reserved to carry
>>>> the IMA measurement log.
>>>
>>>> Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
>>>> Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
>>>> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
>>>> Reported-by: kernel test robot <lkp@intel.com> error: implicit declaration of function 'delete_fdt_mem_rsv' [-Werror,-Wimplicit-function-declaration]
>>>
>>> Much better!  This version limits unnecessarily changing the existing
>>> code to adding a couple of debugging statements, but that looks to be
>>> about it.
>> Yes Mimi - that's correct.
>>
>>>
>>> Based on Chester Lin's "ima_arch" support for arm64 discussion, the IMA generic
>>> EFI support will be defined in ima/ima-efi.c.  Similarly, I think it would make sense to put the generic device tree support in ima/ima_kexec_fdt.c or ima/ima_fdt.c, as opposed to kernel/.  (Refer to my comments on 2/4 about the new file named ima_kexec_fdt.c.)
>>
>> The functions remove_ima_kexec_buffer() and delete_fdt_mem_rsv(), which
>> are defined in kernel/ima_kexec.c and kernel/kexec_file_fdt.c
>> respectively, are needed even when CONFIG_IMA is not defined. These
>> functions need to be called by the current kernel to free the ima kexec
>> buffer resources allocated by the previous kernel. This is the reason,
>> these functions are defined under "kernel" instead of
>> "security/integrity/ima".
>>
>> If there is a better location to move the above C files, please let me
>> know. I'll move them.
> 
> Freeing the previous kernel measurement list is currently called from
> ima_load_kexec_buffer(), only after the measurement list has been
> restored.  The only other time the memory is freed is when the
> allocated memory size isn't sufficient to hold the measurement list,
> which could happen if there is a delay between loading and executing
> the kexec.
> 

There are two "free" operations we need to perform with respect to ima 
buffer on kexec:

1, The ima_free_kexec_buffer() called from ima_load_kexec_buffer() - the 
one you have stated above.

Here we remove the "ima buffer" node from the "OF" tree and free the 
memory pages that were allocated for the measurement list.

This one is already present in ima and there's no change in that in my 
patches.

2, The other one is remove_ima_kexec_buffer() called from 
setup_ima_buffer() defined in "arch/powerpc/kexec/ima.c"

  This function removes the "ima buffer" node from the "FDT" and also 
frees the physical memory reserved for the "ima measurement list" by the 
previous kernel.

  This "free" operation needs to be performed even if the current kernel 
does not support IMA kexec since the previous kernel could have passed 
the IMA measurement list (in FDT and reserved physical memory).

For this reason, remove_ima_kexec_buffer() cannot be defined in "ima" 
but some other place which will be built even if ima is not enabled. I 
chose to define this function in "kernel" since that is guaranteed to be 
always built.

thanks,
  -lakshmi

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

[Thiago Jung Bauermann]

Hello Lakshmi,

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

> On 10/20/20 8:17 PM, Mimi Zohar wrote:
>> On Tue, 2020-10-20 at 19:25 -0700, Lakshmi Ramasubramanian wrote:
>>> On 10/20/20 1:00 PM, Mimi Zohar wrote:
>>>> Hi Lakshmi,
>>>>
>>>> On Wed, 2020-09-30 at 13:59 -0700, Lakshmi Ramasubramanian wrote:
>>>>> The functions remove_ima_buffer() and delete_fdt_mem_rsv() that handle
>>>>> carrying forward the IMA measurement logs on kexec for powerpc do not
>>>>> have architecture specific code, but they are currently defined for
>>>>> powerpc only.
>>>>>
>>>>> remove_ima_buffer() and delete_fdt_mem_rsv() are used to remove
>>>>> the IMA log entry from the device tree and free the memory reserved
>>>>> for the log. These functions need to be defined even if the current
>>>>> kernel does not support carrying forward IMA log across kexec since
>>>>> the previous kernel could have supported that and therefore the current
>>>>> kernel needs to free the allocation.
>>>>>
>>>>> Rename remove_ima_buffer() to remove_ima_kexec_buffer().
>>>>> Define remove_ima_kexec_buffer() and delete_fdt_mem_rsv() in kernel.
>>>>> A later patch in this series will use these functions to free
>>>>> the allocation, if any, made by the previous kernel for ARM64.
>>>>>
>>>>> Define FDT_PROP_IMA_KEXEC_BUFFER for the chosen node, namely
>>>>> "linux,ima-kexec-buffer", that is added to the DTB to hold
>>>>> the address and the size of the memory reserved to carry
>>>>> the IMA measurement log.
>>>>
>>>>> Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
>>>>> Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
>>>>> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
>>>>> Reported-by: kernel test robot <lkp@intel.com> error: implicit declaration of function 'delete_fdt_mem_rsv' [-Werror,-Wimplicit-function-declaration]
>>>>
>>>> Much better!  This version limits unnecessarily changing the existing
>>>> code to adding a couple of debugging statements, but that looks to be
>>>> about it.
>>> Yes Mimi - that's correct.
>>>
>>>>
>>>> Based on Chester Lin's "ima_arch" support for arm64 discussion, the IMA generic
>>>> EFI support will be defined in ima/ima-efi.c.  Similarly, I think it would make sense to put the generic device tree support in ima/ima_kexec_fdt.c or ima/ima_fdt.c, as opposed to kernel/.  (Refer to my comments on 2/4 about the new file named ima_kexec_fdt.c.)
>>>
>>> The functions remove_ima_kexec_buffer() and delete_fdt_mem_rsv(), which
>>> are defined in kernel/ima_kexec.c and kernel/kexec_file_fdt.c
>>> respectively, are needed even when CONFIG_IMA is not defined. These
>>> functions need to be called by the current kernel to free the ima kexec
>>> buffer resources allocated by the previous kernel. This is the reason,
>>> these functions are defined under "kernel" instead of
>>> "security/integrity/ima".
>>>
>>> If there is a better location to move the above C files, please let me
>>> know. I'll move them.
>> Freeing the previous kernel measurement list is currently called from
>> ima_load_kexec_buffer(), only after the measurement list has been
>> restored.  The only other time the memory is freed is when the
>> allocated memory size isn't sufficient to hold the measurement list,
>> which could happen if there is a delay between loading and executing
>> the kexec.
>> 
>
> There are two "free" operations we need to perform with respect to ima buffer on
> kexec:
>
> 1, The ima_free_kexec_buffer() called from ima_load_kexec_buffer() - the one you
> have stated above.
>
> Here we remove the "ima buffer" node from the "OF" tree and free the memory
> pages that were allocated for the measurement list.
>
> This one is already present in ima and there's no change in that in my patches.
>
> 2, The other one is remove_ima_kexec_buffer() called from setup_ima_buffer()
> defined in "arch/powerpc/kexec/ima.c"
>
>  This function removes the "ima buffer" node from the "FDT" and also frees the
> physical memory reserved for the "ima measurement list" by the previous kernel.
>
>  This "free" operation needs to be performed even if the current kernel does not
> support IMA kexec since the previous kernel could have passed the IMA
> measurement list (in FDT and reserved physical memory).
>
> For this reason, remove_ima_kexec_buffer() cannot be defined in "ima" but some
> other place which will be built even if ima is not enabled. I chose to define
> this function in "kernel" since that is guaranteed to be always built.
>
> thanks,
>  -lakshmi

That is true. I believe a more fitting place for these functions is
drivers/of/fdt.c rather than these new files in kernel/. Both CONFIG_PPC
and CONFIG_ARM64 select CONFIG_OF and CONFIG_OF_FLATTREE (indirectly,
via CONFIG_OF_EARLY_FLATTREE) so they will both build that file.

-- 
Thiago Jung Bauermann
IBM Linux Technology Center

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

[Lakshmi Ramasubramanian]

On 10/22/20 8:46 PM, Thiago Jung Bauermann wrote:

Hi Thiago,

> 
> Lakshmi Ramasubramanian <nramas@linux.microsoft.com> writes:
> 
>> On 10/20/20 8:17 PM, Mimi Zohar wrote:
>>> On Tue, 2020-10-20 at 19:25 -0700, Lakshmi Ramasubramanian wrote:
>>>> On 10/20/20 1:00 PM, Mimi Zohar wrote:
>>>>> Hi Lakshmi,
>>>>>
>>>>> On Wed, 2020-09-30 at 13:59 -0700, Lakshmi Ramasubramanian wrote:
>>>>>> The functions remove_ima_buffer() and delete_fdt_mem_rsv() that handle
>>>>>> carrying forward the IMA measurement logs on kexec for powerpc do not
>>>>>> have architecture specific code, but they are currently defined for
>>>>>> powerpc only.
>>>>>>
>>>>>> remove_ima_buffer() and delete_fdt_mem_rsv() are used to remove
>>>>>> the IMA log entry from the device tree and free the memory reserved
>>>>>> for the log. These functions need to be defined even if the current
>>>>>> kernel does not support carrying forward IMA log across kexec since
>>>>>> the previous kernel could have supported that and therefore the current
>>>>>> kernel needs to free the allocation.
>>>>>>
>>>>>> Rename remove_ima_buffer() to remove_ima_kexec_buffer().
>>>>>> Define remove_ima_kexec_buffer() and delete_fdt_mem_rsv() in kernel.
>>>>>> A later patch in this series will use these functions to free
>>>>>> the allocation, if any, made by the previous kernel for ARM64.
>>>>>>
>>>>>> Define FDT_PROP_IMA_KEXEC_BUFFER for the chosen node, namely
>>>>>> "linux,ima-kexec-buffer", that is added to the DTB to hold
>>>>>> the address and the size of the memory reserved to carry
>>>>>> the IMA measurement log.
>>>>>
>>>>>> Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
>>>>>> Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
>>>>>> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
>>>>>> Reported-by: kernel test robot <lkp@intel.com> error: implicit declaration of function 'delete_fdt_mem_rsv' [-Werror,-Wimplicit-function-declaration]
>>>>>
>>>>> Much better!  This version limits unnecessarily changing the existing
>>>>> code to adding a couple of debugging statements, but that looks to be
>>>>> about it.
>>>> Yes Mimi - that's correct.
>>>>
>>>>>
>>>>> Based on Chester Lin's "ima_arch" support for arm64 discussion, the IMA generic
>>>>> EFI support will be defined in ima/ima-efi.c.  Similarly, I think it would make sense to put the generic device tree support in ima/ima_kexec_fdt.c or ima/ima_fdt.c, as opposed to kernel/.  (Refer to my comments on 2/4 about the new file named ima_kexec_fdt.c.)
>>>>
>>>> The functions remove_ima_kexec_buffer() and delete_fdt_mem_rsv(), which
>>>> are defined in kernel/ima_kexec.c and kernel/kexec_file_fdt.c
>>>> respectively, are needed even when CONFIG_IMA is not defined. These
>>>> functions need to be called by the current kernel to free the ima kexec
>>>> buffer resources allocated by the previous kernel. This is the reason,
>>>> these functions are defined under "kernel" instead of
>>>> "security/integrity/ima".
>>>>
>>>> If there is a better location to move the above C files, please let me
>>>> know. I'll move them.
>>> Freeing the previous kernel measurement list is currently called from
>>> ima_load_kexec_buffer(), only after the measurement list has been
>>> restored.  The only other time the memory is freed is when the
>>> allocated memory size isn't sufficient to hold the measurement list,
>>> which could happen if there is a delay between loading and executing
>>> the kexec.
>>>
>>
>> There are two "free" operations we need to perform with respect to ima buffer on
>> kexec:
>>
>> 1, The ima_free_kexec_buffer() called from ima_load_kexec_buffer() - the one you
>> have stated above.
>>
>> Here we remove the "ima buffer" node from the "OF" tree and free the memory
>> pages that were allocated for the measurement list.
>>
>> This one is already present in ima and there's no change in that in my patches.
>>
>> 2, The other one is remove_ima_kexec_buffer() called from setup_ima_buffer()
>> defined in "arch/powerpc/kexec/ima.c"
>>
>>   This function removes the "ima buffer" node from the "FDT" and also frees the
>> physical memory reserved for the "ima measurement list" by the previous kernel.
>>
>>   This "free" operation needs to be performed even if the current kernel does not
>> support IMA kexec since the previous kernel could have passed the IMA
>> measurement list (in FDT and reserved physical memory).
>>
>> For this reason, remove_ima_kexec_buffer() cannot be defined in "ima" but some
>> other place which will be built even if ima is not enabled. I chose to define
>> this function in "kernel" since that is guaranteed to be always built.
>>
>> thanks,
>>   -lakshmi
> 
> That is true. I believe a more fitting place for these functions is
> drivers/of/fdt.c rather than these new files in kernel/. Both CONFIG_PPC
> and CONFIG_ARM64 select CONFIG_OF and CONFIG_OF_FLATTREE (indirectly,
> via CONFIG_OF_EARLY_FLATTREE) so they will both build that file.
> 

I moved the above mentioned functions to drivers/of/fdt.c => it works.

But I am not sure if "drivers/of" is the right place - this driver is 
handling data from firmware and building FDT. I do not see any kexec 
related operations being handled by this driver in the current 
implementation.

Also, being a driver can it be loaded/unloaded on-demand? If yes, it may 
not be available when "ima kexec" calls are needed.

@Rob Herring - what do you think?

thanks,
  -lakshmi