Commit 83ae5408 authored by Lakshmi Ramasubramanian's avatar Lakshmi Ramasubramanian Committed by Zheng Zengkai
Browse files

kexec: Use fdt_appendprop_addrrange() to add ima buffer to FDT 



mainline inclusion
from linux-next
commit 28db15d4
category: feature
bugzilla: 46864
CVE: NA

--------------------------------

fdt_appendprop_addrrange() function adds a property, with the given name,
to the device tree at the given node offset, and also sets the address
and size of the property.  This function should be used to add
"linux,ima-kexec-buffer" property to the device tree and set the address
and size of the IMA measurement buffer, instead of using custom function.

Use fdt_appendprop_addrrange() to add  "linux,ima-kexec-buffer" property
to the device tree.  This property holds the address and size of
the IMA measurement buffer that needs to be passed from the current
kernel to the next kernel across kexec system call.

Remove custom code that is used in setup_ima_buffer() to add
"linux,ima-kexec-buffer" property to the device tree.

Co-developed-by: default avatarPrakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: default avatarPrakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: default avatarLakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reviewed-by: default avatarThiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: default avatarRob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210221174930.27324-12-nramas@linux.microsoft.com



Signed-off-by: default avatarLi Huafei <lihuafei1@huawei.com>
Reviewed-by: default avatarYang Jihong <yangjihong1@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent cc8fc2a5

drivers/of/kexec.c

+5 −52
Original line number Diff line number Diff line
@@ -216,36 +216,6 @@ static void remove_ima_buffer(void *fdt, int chosen_node) 
}



#ifdef CONFIG_IMA_KEXEC

/**

 * write_number - Convert number to big-endian format

 *

 * @p:		Buffer to write the number to

 * @value:	Number to convert

 * @cells:	Number of cells

 *

 * Return: 0 on success, or negative errno on error.

 */

static int write_number(void *p, u64 value, int cells)

{

	if (cells == 1) {

		u32 tmp;



		if (value > U32_MAX)

			return -EINVAL;



		tmp = cpu_to_be32(value);

		memcpy(p, &tmp, sizeof(tmp));

	} else if (cells == 2) {

		u64 tmp;



		tmp = cpu_to_be64(value);

		memcpy(p, &tmp, sizeof(tmp));

	} else

		return -EINVAL;



	return 0;

}



/**

 * setup_ima_buffer - add IMA buffer information to the fdt

 * @image:		kexec image being loaded.
@@ -257,32 +227,15 @@ static int write_number(void *p, u64 value, int cells) 
static int setup_ima_buffer(const struct kimage *image, void *fdt,

			    int chosen_node)

{

	int ret, addr_cells, size_cells, entry_size;

	u8 value[16];

	int ret;



	if (!image->ima_buffer_size)

		return 0;



	ret = get_addr_size_cells(&addr_cells, &size_cells);

	if (ret)

		return ret;



	entry_size = 4 * (addr_cells + size_cells);



	if (entry_size > sizeof(value))

		return -EINVAL;



	ret = write_number(value, image->ima_buffer_addr, addr_cells);

	if (ret)

		return ret;



	ret = write_number(value + 4 * addr_cells, image->ima_buffer_size,

			   size_cells);

	if (ret)

		return ret;



	ret = fdt_setprop(fdt, chosen_node, "linux,ima-kexec-buffer", value,

			  entry_size);

	ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,

				       "linux,ima-kexec-buffer",

				       image->ima_buffer_addr,

				       image->ima_buffer_size);

	if (ret < 0)

		return -EINVAL;