[PATCH v16 05/12] powerpc: Move ima buffer fields to struct kimage

Lakshmi Ramasubramanian
2021-02-04T16:46:34Z

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

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

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

Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Suggested-by: Will Deacon <will@kernel.org>
---
arch/powerpc/include/asm/ima.h | 3 ---
arch/powerpc/include/asm/kexec.h | 5 -----
arch/powerpc/kexec/ima.c | 29 ++++++-----------------------
drivers/of/kexec.c | 23 +++++++++++++++++++++++
include/linux/kexec.h | 5 +++++
include/linux/of.h | 5 +++++
security/integrity/ima/ima_kexec.c | 3 ++-
7 files changed, 41 insertions(+), 32 deletions(-)

diff --git a/arch/powerpc/include/asm/ima.h b/arch/powerpc/include/asm/ima.h
index ead488cf3981..51f64fd06c19 100644
--- a/arch/powerpc/include/asm/ima.h
+++ b/arch/powerpc/include/asm/ima.h
@@ -14,9 +14,6 @@ static inline void remove_ima_buffer(void *fdt, int chosen_node) {}
#endif

#ifdef CONFIG_IMA_KEXEC
-int arch_ima_add_kexec_buffer(struct kimage *image, unsigned long load_addr,
- size_t size);
-
int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node);
#else
static inline int setup_ima_buffer(const struct kimage *image, void *fdt,
diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index dbf09d2f36d0..2248dc27080b 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -111,11 +111,6 @@ struct kimage_arch {
unsigned long elf_headers_mem;
unsigned long elf_headers_sz;
void *elf_headers;
-
-#ifdef CONFIG_IMA_KEXEC
- phys_addr_t ima_buffer_addr;
- size_t ima_buffer_size;
-#endif
};

char *setup_kdump_cmdline(struct kimage *image, char *cmdline,
diff --git a/arch/powerpc/kexec/ima.c b/arch/powerpc/kexec/ima.c
index 720e50e490b6..ed38125e2f87 100644
--- a/arch/powerpc/kexec/ima.c
+++ b/arch/powerpc/kexec/ima.c
@@ -128,23 +128,6 @@ void remove_ima_buffer(void *fdt, int chosen_node)
}

#ifdef CONFIG_IMA_KEXEC
-/**
- * arch_ima_add_kexec_buffer - do arch-specific steps to add the IMA buffer
- *
- * Architectures should use this function to pass on the IMA buffer
- * information to the next kernel.
- *
- * Return: 0 on success, negative errno on error.
- */
-int arch_ima_add_kexec_buffer(struct kimage *image, unsigned long load_addr,
- size_t size)
-{
- image->arch.ima_buffer_addr = load_addr;
- image->arch.ima_buffer_size = size;
-
- return 0;
-}
-
static int write_number(void *p, u64 value, int cells)
{
if (cells == 1) {
@@ -180,7 +163,7 @@ int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node)
u8 value[16];

remove_ima_buffer(fdt, chosen_node);
- if (!image->arch.ima_buffer_size)
+ if (!image->ima_buffer_size)
return 0;

ret = get_addr_size_cells(&addr_cells, &size_cells);
@@ -192,11 +175,11 @@ int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node)
if (entry_size > sizeof(value))
return -EINVAL;

- ret = write_number(value, image->arch.ima_buffer_addr, addr_cells);
+ ret = write_number(value, image->ima_buffer_addr, addr_cells);
if (ret)
return ret;

- ret = write_number(value + 4 * addr_cells, image->arch.ima_buffer_size,
+ ret = write_number(value + 4 * addr_cells, image->ima_buffer_size,
size_cells);
if (ret)
return ret;
@@ -206,13 +189,13 @@ int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node)
if (ret < 0)
return -EINVAL;

- ret = fdt_add_mem_rsv(fdt, image->arch.ima_buffer_addr,
- image->arch.ima_buffer_size);
+ ret = fdt_add_mem_rsv(fdt, image->ima_buffer_addr,
+ image->ima_buffer_size);
if (ret)
return -EINVAL;

pr_debug("IMA buffer at 0x%llx, size = 0x%zx\n",
- image->arch.ima_buffer_addr, image->arch.ima_buffer_size);
+ image->ima_buffer_addr, image->ima_buffer_size);

return 0;
}
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index 4afd3cc1c04a..efbf54f164fd 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -63,6 +63,29 @@ static int fdt_find_and_del_mem_rsv(void *fdt, unsigned long start, unsigned lon
return -ENOENT;
}

+#ifdef CONFIG_IMA_KEXEC
+/**
+ * of_ima_add_kexec_buffer - Add IMA buffer for next kernel
+ *
+ * @image: kimage struct to set IMA buffer data
+ * @load_addr: Starting address where IMA buffer is loaded at
+ * @size: Number of bytes in the IMA buffer
+ *
+ * Use this function to pass on the IMA buffer information to
+ * the next kernel across kexec system call.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int of_ima_add_kexec_buffer(struct kimage *image,
+ unsigned long load_addr, size_t size)
+{
+ image->ima_buffer_addr = load_addr;
+ image->ima_buffer_size = size;
+
+ return 0;
+}
+#endif /* CONFIG_IMA_KEXEC */
+
/*
* of_kexec_setup_new_fdt - modify /chosen and memory reservation for the next kernel
*
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 9e93bef52968..c142a1e5568d 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -300,6 +300,11 @@ struct kimage {
/* Information for loading purgatory */
struct purgatory_info purgatory_info;
#endif
+
+#ifdef CONFIG_IMA_KEXEC
+ phys_addr_t ima_buffer_addr;
+ size_t ima_buffer_size;
+#endif
};

/* kexec interface functions */
diff --git a/include/linux/of.h b/include/linux/of.h
index 41e256adf758..551117c32773 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -564,6 +564,11 @@ int of_kexec_setup_new_fdt(const struct kimage *image, void *fdt,
unsigned long initrd_load_addr, unsigned long initrd_len,
const char *cmdline);

+#ifdef CONFIG_IMA_KEXEC
+int of_ima_add_kexec_buffer(struct kimage *image,
+ unsigned long load_addr, size_t size);
+#endif /* CONFIG_IMA_KEXEC */
+
#else /* CONFIG_OF */

static inline void of_core_init(void)
diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c
index 121de3e04af2..345b78515774 100644
--- a/security/integrity/ima/ima_kexec.c
+++ b/security/integrity/ima/ima_kexec.c
@@ -10,6 +10,7 @@
#include <linux/seq_file.h>
#include <linux/vmalloc.h>
#include <linux/kexec.h>
+#include <linux/of.h>
#include "ima.h"

#ifdef CONFIG_IMA_KEXEC
@@ -122,7 +123,7 @@ void ima_add_kexec_buffer(struct kimage *image)
return;
}

- ret = arch_ima_add_kexec_buffer(image, kbuf.mem, kexec_segment_size);
+ ret = of_ima_add_kexec_buffer(image, kbuf.mem, kexec_segment_size);
if (ret) {
pr_err("Error passing over kexec measurement buffer.\n");
return;
--
2.30.0