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Commit ab6b1d1f authored by Thiago Jung Bauermann's avatar Thiago Jung Bauermann Committed by Linus Torvalds
Browse files

powerpc: ima: send the kexec buffer to the next kernel 

The IMA kexec buffer allows the currently running kernel to pass the
measurement list via a kexec segment to the kernel that will be kexec'd.

This is the architecture-specific part of setting up the IMA kexec
buffer for the next kernel.  It will be used in the next patch.

Link: http://lkml.kernel.org/r/1480554346-29071-6-git-send-email-zohar@linux.vnet.ibm.com


Signed-off-by: default avatarThiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: default avatarMimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andreas Steffen <andreas.steffen@strongswan.org>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: Josh Sklar <sklar@linux.vnet.ibm.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d158847a

arch/powerpc/include/asm/ima.h

+16 −0
Original line number Diff line number Diff line 
#ifndef _ASM_POWERPC_IMA_H

#define _ASM_POWERPC_IMA_H



struct kimage;



int ima_get_kexec_buffer(void **addr, size_t *size);

int ima_free_kexec_buffer(void);
@@ -10,4 +12,18 @@ void remove_ima_buffer(void *fdt, int chosen_node); 
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,

				   int chosen_node)

{

	remove_ima_buffer(fdt, chosen_node);

	return 0;

}

#endif /* CONFIG_IMA_KEXEC */



#endif /* _ASM_POWERPC_IMA_H */

arch/powerpc/include/asm/kexec.h

+12 −2
Original line number Diff line number Diff line
@@ -94,11 +94,21 @@ static inline bool kdump_in_progress(void) 
#ifdef CONFIG_KEXEC_FILE

extern struct kexec_file_ops kexec_elf64_ops;



#ifdef CONFIG_IMA_KEXEC

#define ARCH_HAS_KIMAGE_ARCH



struct kimage_arch {

	phys_addr_t ima_buffer_addr;

	size_t ima_buffer_size;

};

#endif



int setup_purgatory(struct kimage *image, const void *slave_code,

		    const void *fdt, unsigned long kernel_load_addr,

		    unsigned long fdt_load_addr);

int setup_new_fdt(void *fdt, unsigned long initrd_load_addr,

		  unsigned long initrd_len, const char *cmdline);

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);

#endif /* CONFIG_KEXEC_FILE */

arch/powerpc/kernel/ima_kexec.c

+91 −0
Original line number Diff line number Diff line
@@ -130,3 +130,94 @@ void remove_ima_buffer(void *fdt, int chosen_node) 
	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

 *

 * 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) {

		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.

 * @fdt:		Flattened device tree for the next kernel.

 * @chosen_node:	Offset to the chosen node.

 *

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

 */

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);

	if (!image->arch.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->arch.ima_buffer_addr, addr_cells);

	if (ret)

		return ret;



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

			   size_cells);

	if (ret)

		return ret;



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

			  entry_size);

	if (ret < 0)

		return -EINVAL;



	ret = fdt_add_mem_rsv(fdt, image->arch.ima_buffer_addr,

			      image->arch.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);



	return 0;

}

#endif /* CONFIG_IMA_KEXEC */

arch/powerpc/kernel/kexec_elf_64.c

+1 −1
Original line number Diff line number Diff line
@@ -627,7 +627,7 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, 
		goto out;

	}



	ret = setup_new_fdt(fdt, initrd_load_addr, initrd_len, cmdline);

	ret = setup_new_fdt(image, fdt, initrd_load_addr, initrd_len, cmdline);

	if (ret)

		goto out;

arch/powerpc/kernel/machine_kexec_file_64.c

+9 −3
Original line number Diff line number Diff line
@@ -210,6 +210,7 @@ int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size) 


/*

 * setup_new_fdt - modify /chosen and memory reservation for the next kernel

 * @image:		kexec image being loaded.

 * @fdt:		Flattened device tree for the next kernel.

 * @initrd_load_addr:	Address where the next initrd will be loaded.

 * @initrd_len:		Size of the next initrd, or 0 if there will be none.
@@ -218,8 +219,9 @@ int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size) 
 *

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

 */

int setup_new_fdt(void *fdt, unsigned long initrd_load_addr,

		  unsigned long initrd_len, const char *cmdline)

int setup_new_fdt(const struct kimage *image, void *fdt,

		  unsigned long initrd_load_addr, unsigned long initrd_len,

		  const char *cmdline)

{

	int ret, chosen_node;

	const void *prop;
@@ -329,7 +331,11 @@ int setup_new_fdt(void *fdt, unsigned long initrd_load_addr, 
		}

	}



	remove_ima_buffer(fdt, chosen_node);

	ret = setup_ima_buffer(image, fdt, chosen_node);

	if (ret) {

		pr_err("Error setting up the new device tree.\n");

		return ret;

	}



	ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0);

	if (ret) {