This patch moves the non-architecture specific code out of powerpc and
 adds to security/ima. 
Update the arm64 and powerpc kexec file load paths to carry the IMA measurement
logs.

Signed-off-by: Prakhar Srivastava <prsr...@linux.microsoft.com>
---
 arch/arm64/Kconfig                     |   1 +
 arch/arm64/include/asm/ima.h           |  24 ++++
 arch/arm64/include/asm/kexec.h         |   3 +
 arch/arm64/kernel/machine_kexec_file.c |  47 ++++++--
 arch/powerpc/include/asm/ima.h         |   9 --
 arch/powerpc/kexec/ima.c               | 117 +------------------
 security/integrity/ima/ima_kexec.c     | 151 +++++++++++++++++++++++++
 7 files changed, 219 insertions(+), 133 deletions(-)
 create mode 100644 arch/arm64/include/asm/ima.h

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 5d513f461957..3d544e2e25e6 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1070,6 +1070,7 @@ 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/include/asm/ima.h b/arch/arm64/include/asm/ima.h
new file mode 100644
index 000000000000..8946bae8baa2
--- /dev/null
+++ b/arch/arm64/include/asm/ima.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#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);
+
+int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node);
+#else
+static inline int arch_ima_add_kexec_buffer(struct kimage *image,
+                       unsigned long load_addr, size_t size)
+{
+       return 0;
+}
+static inline int setup_ima_buffer(const struct kimage *image, void *fdt,
+                                  int chosen_node)
+{
+       return 0;
+}
+#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/machine_kexec_file.c 
b/arch/arm64/kernel/machine_kexec_file.c
index b40c3b0def92..1e9007c926db 100644
--- a/arch/arm64/kernel/machine_kexec_file.c
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -24,20 +24,37 @@
 #include <asm/byteorder.h>
 
 /* relevant device tree properties */
-#define FDT_PROP_KEXEC_ELFHDR  "linux,elfcorehdr"
-#define FDT_PROP_MEM_RANGE     "linux,usable-memory-range"
-#define FDT_PROP_INITRD_START  "linux,initrd-start"
-#define FDT_PROP_INITRD_END    "linux,initrd-end"
-#define FDT_PROP_BOOTARGS      "bootargs"
-#define FDT_PROP_KASLR_SEED    "kaslr-seed"
-#define FDT_PROP_RNG_SEED      "rng-seed"
-#define RNG_SEED_SIZE          128
+#define FDT_PROP_KEXEC_ELFHDR          "linux,elfcorehdr"
+#define FDT_PROP_MEM_RANGE             "linux,usable-memory-range"
+#define FDT_PROP_INITRD_START          "linux,initrd-start"
+#define FDT_PROP_INITRD_END            "linux,initrd-end"
+#define FDT_PROP_BOOTARGS              "bootargs"
+#define FDT_PROP_KASLR_SEED            "kaslr-seed"
+#define FDT_PROP_RNG_SEED              "rng-seed"
+#define FDT_PROP_IMA_KEXEC_BUFFER      "linux,ima-kexec-buffer"
+#define RNG_SEED_SIZE                  128
 
 const struct kexec_file_ops * const kexec_file_loaders[] = {
        &kexec_image_ops,
        NULL
 };
 
+/**
+ * arch_ima_add_kexec_buffer - do arch-specific steps to add the IMA buffer
+ *
+ * Architectures should use this function to pass on the IMA buffer
+ * information to the next kernel.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int arch_ima_add_kexec_buffer(struct kimage *image, unsigned long load_addr,
+                             size_t size)
+{
+       image->arch.ima_buffer_addr = load_addr;
+       image->arch.ima_buffer_size = size;
+       return 0;
+}
+
 int arch_kimage_file_post_load_cleanup(struct kimage *image)
 {
        vfree(image->arch.dtb);
@@ -66,6 +83,9 @@ static int setup_dtb(struct kimage *image,
        if (ret && ret != -FDT_ERR_NOTFOUND)
                goto out;
        ret = fdt_delprop(dtb, off, FDT_PROP_MEM_RANGE);
+       if (ret && ret != -FDT_ERR_NOTFOUND)
+               goto out;
+       ret = fdt_delprop(dtb, off, FDT_PROP_IMA_KEXEC_BUFFER);
        if (ret && ret != -FDT_ERR_NOTFOUND)
                goto out;
 
@@ -119,6 +139,17 @@ static int setup_dtb(struct kimage *image,
                        goto out;
        }
 
+       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);
+
+       }
+
        /* add kaslr-seed */
        ret = fdt_delprop(dtb, off, FDT_PROP_KASLR_SEED);
        if (ret == -FDT_ERR_NOTFOUND)
diff --git a/arch/powerpc/include/asm/ima.h b/arch/powerpc/include/asm/ima.h
index ead488cf3981..80b83881fa03 100644
--- a/arch/powerpc/include/asm/ima.h
+++ b/arch/powerpc/include/asm/ima.h
@@ -4,15 +4,6 @@
 
 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);
diff --git a/arch/powerpc/kexec/ima.c b/arch/powerpc/kexec/ima.c
index 720e50e490b6..537e4f82a050 100644
--- a/arch/powerpc/kexec/ima.c
+++ b/arch/powerpc/kexec/ima.c
@@ -12,121 +12,6 @@
 #include <linux/memblock.h>
 #include <linux/libfdt.h>
 
-static int get_addr_size_cells(int *addr_cells, int *size_cells)
-{
-       struct device_node *root;
-
-       root = of_find_node_by_path("/");
-       if (!root)
-               return -EINVAL;
-
-       *addr_cells = of_n_addr_cells(root);
-       *size_cells = of_n_size_cells(root);
-
-       of_node_put(root);
-
-       return 0;
-}
-
-static int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr,
-                              size_t *size)
-{
-       int ret, addr_cells, size_cells;
-
-       ret = get_addr_size_cells(&addr_cells, &size_cells);
-       if (ret)
-               return ret;
-
-       if (len < 4 * (addr_cells + size_cells))
-               return -ENOENT;
-
-       *addr = of_read_number(prop, addr_cells);
-       *size = of_read_number(prop + 4 * addr_cells, size_cells);
-
-       return 0;
-}
-
-/**
- * ima_get_kexec_buffer - get IMA buffer from the previous kernel
- * @addr:      On successful return, set to point to the buffer contents.
- * @size:      On successful return, set to the buffer size.
- *
- * Return: 0 on success, negative errno on error.
- */
-int ima_get_kexec_buffer(void **addr, size_t *size)
-{
-       int ret, len;
-       unsigned long tmp_addr;
-       size_t tmp_size;
-       const void *prop;
-
-       prop = of_get_property(of_chosen, "linux,ima-kexec-buffer", &len);
-       if (!prop)
-               return -ENOENT;
-
-       ret = do_get_kexec_buffer(prop, len, &tmp_addr, &tmp_size);
-       if (ret)
-               return ret;
-
-       *addr = __va(tmp_addr);
-       *size = tmp_size;
-
-       return 0;
-}
-
-/**
- * ima_free_kexec_buffer - free memory used by the IMA buffer
- */
-int ima_free_kexec_buffer(void)
-{
-       int ret;
-       unsigned long addr;
-       size_t size;
-       struct property *prop;
-
-       prop = of_find_property(of_chosen, "linux,ima-kexec-buffer", NULL);
-       if (!prop)
-               return -ENOENT;
-
-       ret = do_get_kexec_buffer(prop->value, prop->length, &addr, &size);
-       if (ret)
-               return ret;
-
-       ret = of_remove_property(of_chosen, prop);
-       if (ret)
-               return ret;
-
-       return memblock_free(addr, size);
-
-}
-
-/**
- * remove_ima_buffer - remove the IMA buffer property and reservation from @fdt
- *
- * The IMA measurement buffer is of no use to a subsequent kernel, so we always
- * remove it from the device tree.
- */
-void remove_ima_buffer(void *fdt, int chosen_node)
-{
-       int ret, len;
-       unsigned long addr;
-       size_t size;
-       const void *prop;
-
-       prop = fdt_getprop(fdt, chosen_node, "linux,ima-kexec-buffer", &len);
-       if (!prop)
-               return;
-
-       ret = do_get_kexec_buffer(prop, len, &addr, &size);
-       fdt_delprop(fdt, chosen_node, "linux,ima-kexec-buffer");
-       if (ret)
-               return;
-
-       ret = delete_fdt_mem_rsv(fdt, addr, size);
-       if (!ret)
-               pr_debug("Removed old IMA buffer reservation.\n");
-}
-
 #ifdef CONFIG_IMA_KEXEC
 /**
  * arch_ima_add_kexec_buffer - do arch-specific steps to add the IMA buffer
@@ -179,7 +64,7 @@ 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_buffer(fdt, chosen_node);
        if (!image->arch.ima_buffer_size)
                return 0;
 
diff --git a/security/integrity/ima/ima_kexec.c 
b/security/integrity/ima/ima_kexec.c
index 121de3e04af2..36887ed4ff82 100644
--- a/security/integrity/ima/ima_kexec.c
+++ b/security/integrity/ima/ima_kexec.c
@@ -10,8 +10,159 @@
 #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 "ima.h"
 
+static int get_addr_size_cells(int *addr_cells, int *size_cells)
+{
+       struct device_node *root;
+
+       root = of_find_node_by_path("/");
+       if (!root)
+               return -EINVAL;
+
+       *addr_cells = of_n_addr_cells(root);
+       *size_cells = of_n_size_cells(root);
+
+       of_node_put(root);
+
+       return 0;
+}
+
+static int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr,
+                              size_t *size)
+{
+       int ret, addr_cells, size_cells;
+
+       ret = get_addr_size_cells(&addr_cells, &size_cells);
+       if (ret)
+               return ret;
+
+       if (len < 4 * (addr_cells + size_cells))
+               return -ENOENT;
+
+       *addr = of_read_number(prop, addr_cells);
+       *size = of_read_number(prop + 4 * addr_cells, size_cells);
+
+       return 0;
+}
+
+/**
+ * ima_get_kexec_buffer - get IMA buffer from the previous kernel
+ * @addr:      On successful return, set to point to the buffer contents.
+ * @size:      On successful return, set to the buffer size.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int ima_get_kexec_buffer(void **addr, size_t *size)
+{
+       int ret, len;
+       unsigned long tmp_addr;
+       size_t tmp_size;
+       const void *prop;
+
+       prop = of_get_property(of_chosen, "linux,ima-kexec-buffer", &len);
+       if (!prop)
+               return -ENOENT;
+
+       ret = do_get_kexec_buffer(prop, len, &tmp_addr, &tmp_size);
+       if (ret)
+               return ret;
+
+       *addr = __va(tmp_addr);
+       *size = tmp_size;
+
+       return 0;
+}
+
+/**
+ * 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;
+}
+
+/**
+ * ima_free_kexec_buffer - free memory used by the IMA buffer
+ */
+int ima_free_kexec_buffer(void)
+{
+       int ret;
+       unsigned long addr;
+       size_t size;
+       struct property *prop;
+
+       prop = of_find_property(of_chosen, "linux,ima-kexec-buffer", NULL);
+       if (!prop)
+               return -ENOENT;
+
+       ret = do_get_kexec_buffer(prop->value, prop->length, &addr, &size);
+       if (ret)
+               return ret;
+
+       ret = of_remove_property(of_chosen, prop);
+       if (ret)
+               return ret;
+
+       return memblock_free(addr, size);
+
+}
+
+/**
+ * remove_ima_buffer - remove the IMA buffer property and reservation from @fdt
+ *
+ * The IMA measurement buffer is of no use to a subsequent kernel, so we always
+ * remove it from the device tree.
+ */
+void remove_ima_buffer(void *fdt, int chosen_node)
+{
+       int ret, len;
+       unsigned long addr;
+       size_t size;
+       const void *prop;
+
+       prop = fdt_getprop(fdt, chosen_node, "linux,ima-kexec-buffer", &len);
+       if (!prop)
+               return;
+
+       ret = do_get_kexec_buffer(prop, len, &addr, &size);
+       fdt_delprop(fdt, chosen_node, "linux,ima-kexec-buffer");
+       if (ret)
+               return;
+
+       ret = delete_fdt_mem_rsv(fdt, addr, size);
+       if (!ret)
+               pr_debug("Removed old IMA buffer reservation.\n");
+}
+
+
 #ifdef CONFIG_IMA_KEXEC
 static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer,
                                     unsigned long segment_size)
-- 
2.25.1

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