[v4,4/5] of: kexec: Refactor IMA buffer related functions to make them reusable

Refactor IMA buffer related functions to make them reusable for carrying
TPM logs across kexec.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>

---
v4:
 - Move debug output into setup_buffer()
---
 drivers/of/kexec.c | 131 ++++++++++++++++++++++++++-------------------
 1 file changed, 76 insertions(+), 55 deletions(-)

[Cc'ing Borislav Petkov <bp@suse.de>, Jonathan McDowell <noodles@fb.com
>]

Hi Stefan,

On Thu, 2022-06-30 at 22:26 -0400, Stefan Berger wrote:
> Refactor IMA buffer related functions to make them reusable for carrying
> TPM logs across kexec.
> 
> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Frank Rowand <frowand.list@gmail.com>
> Cc: Mimi Zohar <zohar@linux.ibm.com>

Refactoring the ima_get_kexec_buffer sounds good, but there's a merge
conflict with Jonathan McDowell's commit "b69a2afd5afc x86/kexec: Carry
forward IMA measurement log on kexec".
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/of/kexec.c

thanks,

Mimi

> 
> ---
> v4:
>  - Move debug output into setup_buffer()
> ---
>  drivers/of/kexec.c | 131 ++++++++++++++++++++++++++-------------------
>  1 file changed, 76 insertions(+), 55 deletions(-)
> 
> diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
> index c4f9b6655a2e..0710703acfb0 100644
> --- a/drivers/of/kexec.c
> +++ b/drivers/of/kexec.c
> @@ -115,48 +115,59 @@ static int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr,
>  	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)
> +static int get_kexec_buffer(const char *name, unsigned long *addr, size_t *size)
>  {
>  	int ret, len;
> -	unsigned long tmp_addr;
>  	unsigned long start_pfn, end_pfn;
> -	size_t tmp_size;
>  	const void *prop;
>  
> -	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
> -		return -ENOTSUPP;
> -
> -	prop = of_get_property(of_chosen, "linux,ima-kexec-buffer", &len);
> +	prop = of_get_property(of_chosen, name, &len);
>  	if (!prop)
>  		return -ENOENT;
>  
> -	ret = do_get_kexec_buffer(prop, len, &tmp_addr, &tmp_size);
> +	ret = do_get_kexec_buffer(prop, len, addr, size);
>  	if (ret)
>  		return ret;
>  
> -	/* Do some sanity on the returned size for the ima-kexec buffer */
> -	if (!tmp_size)
> +	/* Do some sanity on the returned size for the kexec buffer */
> +	if (!*size)
>  		return -ENOENT;
>  
>  	/*
>  	 * Calculate the PFNs for the buffer and ensure
>  	 * they are with in addressable memory.
>  	 */
> -	start_pfn = PHYS_PFN(tmp_addr);
> -	end_pfn = PHYS_PFN(tmp_addr + tmp_size - 1);
> +	start_pfn = PHYS_PFN(*addr);
> +	end_pfn = PHYS_PFN(*addr + *size - 1);
>  	if (!page_is_ram(start_pfn) || !page_is_ram(end_pfn)) {
> -		pr_warn("IMA buffer at 0x%lx, size = 0x%zx beyond memory\n",
> -			tmp_addr, tmp_size);
> +		pr_warn("%s buffer at 0x%lx, size = 0x%zx beyond memory\n",
> +			name, *addr, *size);
>  		return -EINVAL;
>  	}
>  
> +	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;
> +	unsigned long tmp_addr;
> +	size_t tmp_size;
> +
> +	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
> +		return -ENOTSUPP;
> +
> +	ret = get_kexec_buffer("linux,ima-kexec-buffer", &tmp_addr, &tmp_size);
> +	if (ret)
> +		return ret;
> +
>  	*addr = __va(tmp_addr);
>  	*size = tmp_size;
>  
> @@ -191,72 +202,82 @@ int ima_free_kexec_buffer(void)
>  	return memblock_phys_free(addr, size);
>  }
>  
> -/**
> - * remove_ima_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.
> - */
> -static void remove_ima_buffer(void *fdt, int chosen_node)
> +static int remove_buffer(void *fdt, int chosen_node, const char *name)
>  {
>  	int ret, len;
>  	unsigned long addr;
>  	size_t size;
>  	const void *prop;
>  
> -	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
> -		return;
> -
> -	prop = fdt_getprop(fdt, chosen_node, "linux,ima-kexec-buffer", &len);
> +	prop = fdt_getprop(fdt, chosen_node, name, &len);
>  	if (!prop)
> -		return;
> +		return -ENOENT;
>  
>  	ret = do_get_kexec_buffer(prop, len, &addr, &size);
> -	fdt_delprop(fdt, chosen_node, "linux,ima-kexec-buffer");
> +	fdt_delprop(fdt, chosen_node, name);
>  	if (ret)
> -		return;
> +		return ret;
>  
>  	ret = fdt_find_and_del_mem_rsv(fdt, addr, size);
>  	if (!ret)
> -		pr_debug("Removed old IMA buffer reservation.\n");
> +		pr_debug("Remove old %s buffer reserveration", name);
> +	return ret;
>  }
>  
> -#ifdef CONFIG_IMA_KEXEC
>  /**
> - * 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.
> + * remove_ima_buffer - remove the IMA buffer property and reservation from @fdt
>   *
> - * Return: 0 on success, or negative errno on error.
> + * @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.
>   */
> -static int setup_ima_buffer(const struct kimage *image, void *fdt,
> -			    int chosen_node)
> +static void remove_ima_buffer(void *fdt, int chosen_node)
> +{
> +	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
> +		return;
> +
> +	remove_buffer(fdt, chosen_node, "linux,ima-kexec-buffer");
> +}
> +
> +#ifdef CONFIG_IMA_KEXEC
> +static int setup_buffer(void *fdt, int chosen_node, const char *name,
> +			phys_addr_t addr, size_t size)
>  {
>  	int ret;
>  
> -	if (!image->ima_buffer_size)
> +	if (!size)
>  		return 0;
>  
>  	ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
> -				       "linux,ima-kexec-buffer",
> -				       image->ima_buffer_addr,
> -				       image->ima_buffer_size);
> +				       name, addr, size);
>  	if (ret < 0)
>  		return -EINVAL;
>  
> -	ret = fdt_add_mem_rsv(fdt, image->ima_buffer_addr,
> -			      image->ima_buffer_size);
> +	ret = fdt_add_mem_rsv(fdt, addr, size);
>  	if (ret)
>  		return -EINVAL;
>  
> -	pr_debug("IMA buffer at 0x%pa, size = 0x%zx\n",
> -		 &image->ima_buffer_addr, image->ima_buffer_size);
> +	pr_debug("%s at 0x%pa, size = 0x%zx\n", name, &addr, size);
>  
>  	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.
> + */
> +static int setup_ima_buffer(const struct kimage *image, void *fdt,
> +			    int chosen_node)
> +{
> +	return setup_buffer(fdt, chosen_node, "linux,ima-kexec-buffer",
> +			    image->ima_buffer_addr, image->ima_buffer_size);
>  }
>  #else /* CONFIG_IMA_KEXEC */
>  static inline int setup_ima_buffer(const struct kimage *image, void *fdt,

On Tue, Jul 05, 2022 at 06:46:54PM -0400, Mimi Zohar wrote:
> [Cc'ing Borislav Petkov <bp@suse.de>, Jonathan McDowell <noodles@fb.com
> >]
> 
> Hi Stefan,
> 
> On Thu, 2022-06-30 at 22:26 -0400, Stefan Berger wrote:
> > Refactor IMA buffer related functions to make them reusable for carrying
> > TPM logs across kexec.
> > 
> > Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> > Cc: Rob Herring <robh+dt@kernel.org>
> > Cc: Frank Rowand <frowand.list@gmail.com>
> > Cc: Mimi Zohar <zohar@linux.ibm.com>
> 
> Refactoring the ima_get_kexec_buffer sounds good, but there's a merge
> conflict with Jonathan McDowell's commit "b69a2afd5afc x86/kexec: Carry
> forward IMA measurement log on kexec".
> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/of/kexec.c

None of this looks difficult to re-do on top of my changes that are in
-next; the only thing to watch out for is a couple of functions have
moved into the __init section but that looks appropriate for your TPM
log carry-over too.

> > ---
> > v4:
> >  - Move debug output into setup_buffer()
> > ---
> >  drivers/of/kexec.c | 131 ++++++++++++++++++++++++++-------------------
> >  1 file changed, 76 insertions(+), 55 deletions(-)
> > 
> > diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
> > index c4f9b6655a2e..0710703acfb0 100644
> > --- a/drivers/of/kexec.c
> > +++ b/drivers/of/kexec.c
> > @@ -115,48 +115,59 @@ static int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr,
> >  	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)
> > +static int get_kexec_buffer(const char *name, unsigned long *addr, size_t *size)
> >  {
> >  	int ret, len;
> > -	unsigned long tmp_addr;
> >  	unsigned long start_pfn, end_pfn;
> > -	size_t tmp_size;
> >  	const void *prop;
> >  
> > -	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
> > -		return -ENOTSUPP;
> > -
> > -	prop = of_get_property(of_chosen, "linux,ima-kexec-buffer", &len);
> > +	prop = of_get_property(of_chosen, name, &len);
> >  	if (!prop)
> >  		return -ENOENT;
> >  
> > -	ret = do_get_kexec_buffer(prop, len, &tmp_addr, &tmp_size);
> > +	ret = do_get_kexec_buffer(prop, len, addr, size);
> >  	if (ret)
> >  		return ret;
> >  
> > -	/* Do some sanity on the returned size for the ima-kexec buffer */
> > -	if (!tmp_size)
> > +	/* Do some sanity on the returned size for the kexec buffer */
> > +	if (!*size)
> >  		return -ENOENT;
> >  
> >  	/*
> >  	 * Calculate the PFNs for the buffer and ensure
> >  	 * they are with in addressable memory.
> >  	 */
> > -	start_pfn = PHYS_PFN(tmp_addr);
> > -	end_pfn = PHYS_PFN(tmp_addr + tmp_size - 1);
> > +	start_pfn = PHYS_PFN(*addr);
> > +	end_pfn = PHYS_PFN(*addr + *size - 1);
> >  	if (!page_is_ram(start_pfn) || !page_is_ram(end_pfn)) {
> > -		pr_warn("IMA buffer at 0x%lx, size = 0x%zx beyond memory\n",
> > -			tmp_addr, tmp_size);
> > +		pr_warn("%s buffer at 0x%lx, size = 0x%zx beyond memory\n",
> > +			name, *addr, *size);
> >  		return -EINVAL;
> >  	}
> >  
> > +	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;
> > +	unsigned long tmp_addr;
> > +	size_t tmp_size;
> > +
> > +	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
> > +		return -ENOTSUPP;
> > +
> > +	ret = get_kexec_buffer("linux,ima-kexec-buffer", &tmp_addr, &tmp_size);
> > +	if (ret)
> > +		return ret;
> > +
> >  	*addr = __va(tmp_addr);
> >  	*size = tmp_size;
> >  
> > @@ -191,72 +202,82 @@ int ima_free_kexec_buffer(void)
> >  	return memblock_phys_free(addr, size);
> >  }
> >  
> > -/**
> > - * remove_ima_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.
> > - */
> > -static void remove_ima_buffer(void *fdt, int chosen_node)
> > +static int remove_buffer(void *fdt, int chosen_node, const char *name)
> >  {
> >  	int ret, len;
> >  	unsigned long addr;
> >  	size_t size;
> >  	const void *prop;
> >  
> > -	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
> > -		return;
> > -
> > -	prop = fdt_getprop(fdt, chosen_node, "linux,ima-kexec-buffer", &len);
> > +	prop = fdt_getprop(fdt, chosen_node, name, &len);
> >  	if (!prop)
> > -		return;
> > +		return -ENOENT;
> >  
> >  	ret = do_get_kexec_buffer(prop, len, &addr, &size);
> > -	fdt_delprop(fdt, chosen_node, "linux,ima-kexec-buffer");
> > +	fdt_delprop(fdt, chosen_node, name);
> >  	if (ret)
> > -		return;
> > +		return ret;
> >  
> >  	ret = fdt_find_and_del_mem_rsv(fdt, addr, size);
> >  	if (!ret)
> > -		pr_debug("Removed old IMA buffer reservation.\n");
> > +		pr_debug("Remove old %s buffer reserveration", name);
> > +	return ret;
> >  }
> >  
> > -#ifdef CONFIG_IMA_KEXEC
> >  /**
> > - * 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.
> > + * remove_ima_buffer - remove the IMA buffer property and reservation from @fdt
> >   *
> > - * Return: 0 on success, or negative errno on error.
> > + * @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.
> >   */
> > -static int setup_ima_buffer(const struct kimage *image, void *fdt,
> > -			    int chosen_node)
> > +static void remove_ima_buffer(void *fdt, int chosen_node)
> > +{
> > +	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
> > +		return;
> > +
> > +	remove_buffer(fdt, chosen_node, "linux,ima-kexec-buffer");
> > +}
> > +
> > +#ifdef CONFIG_IMA_KEXEC
> > +static int setup_buffer(void *fdt, int chosen_node, const char *name,
> > +			phys_addr_t addr, size_t size)
> >  {
> >  	int ret;
> >  
> > -	if (!image->ima_buffer_size)
> > +	if (!size)
> >  		return 0;
> >  
> >  	ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
> > -				       "linux,ima-kexec-buffer",
> > -				       image->ima_buffer_addr,
> > -				       image->ima_buffer_size);
> > +				       name, addr, size);
> >  	if (ret < 0)
> >  		return -EINVAL;
> >  
> > -	ret = fdt_add_mem_rsv(fdt, image->ima_buffer_addr,
> > -			      image->ima_buffer_size);
> > +	ret = fdt_add_mem_rsv(fdt, addr, size);
> >  	if (ret)
> >  		return -EINVAL;
> >  
> > -	pr_debug("IMA buffer at 0x%pa, size = 0x%zx\n",
> > -		 &image->ima_buffer_addr, image->ima_buffer_size);
> > +	pr_debug("%s at 0x%pa, size = 0x%zx\n", name, &addr, size);
> >  
> >  	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.
> > + */
> > +static int setup_ima_buffer(const struct kimage *image, void *fdt,
> > +			    int chosen_node)
> > +{
> > +	return setup_buffer(fdt, chosen_node, "linux,ima-kexec-buffer",
> > +			    image->ima_buffer_addr, image->ima_buffer_size);
> >  }
> >  #else /* CONFIG_IMA_KEXEC */
> >  static inline int setup_ima_buffer(const struct kimage *image, void *fdt,

On 7/6/22 10:00, Jonathan McDowell wrote:
> On Tue, Jul 05, 2022 at 06:46:54PM -0400, Mimi Zohar wrote:
>> [Cc'ing Borislav Petkov <bp@suse.de>, Jonathan McDowell <noodles@fb.com
>>> ]
>>
>> Hi Stefan,
>>
>> On Thu, 2022-06-30 at 22:26 -0400, Stefan Berger wrote:
>>> Refactor IMA buffer related functions to make them reusable for carrying
>>> TPM logs across kexec.
>>>
>>> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
>>> Cc: Rob Herring <robh+dt@kernel.org>
>>> Cc: Frank Rowand <frowand.list@gmail.com>
>>> Cc: Mimi Zohar <zohar@linux.ibm.com>
>>
>> Refactoring the ima_get_kexec_buffer sounds good, but there's a merge
>> conflict with Jonathan McDowell's commit "b69a2afd5afc x86/kexec: Carry
>> forward IMA measurement log on kexec".
>> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/of/kexec.c
> 
> None of this looks difficult to re-do on top of my changes that are in
> -next; the only thing to watch out for is a couple of functions have
> moved into the __init section but that looks appropriate for your TPM
> log carry-over too.

Yes, I am rebasing my series now and will post v5 of this series with 
your patch prepended as well.

    Stefan

> 
>>> ---
>>> v4:
>>>   - Move debug output into setup_buffer()
>>> ---
>>>   drivers/of/kexec.c | 131 ++++++++++++++++++++++++++-------------------
>>>   1 file changed, 76 insertions(+), 55 deletions(-)
>>>
>>> diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
>>> index c4f9b6655a2e..0710703acfb0 100644
>>> --- a/drivers/of/kexec.c
>>> +++ b/drivers/of/kexec.c
>>> @@ -115,48 +115,59 @@ static int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr,
>>>   	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)
>>> +static int get_kexec_buffer(const char *name, unsigned long *addr, size_t *size)
>>>   {
>>>   	int ret, len;
>>> -	unsigned long tmp_addr;
>>>   	unsigned long start_pfn, end_pfn;
>>> -	size_t tmp_size;
>>>   	const void *prop;
>>>   
>>> -	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
>>> -		return -ENOTSUPP;
>>> -
>>> -	prop = of_get_property(of_chosen, "linux,ima-kexec-buffer", &len);
>>> +	prop = of_get_property(of_chosen, name, &len);
>>>   	if (!prop)
>>>   		return -ENOENT;
>>>   
>>> -	ret = do_get_kexec_buffer(prop, len, &tmp_addr, &tmp_size);
>>> +	ret = do_get_kexec_buffer(prop, len, addr, size);
>>>   	if (ret)
>>>   		return ret;
>>>   
>>> -	/* Do some sanity on the returned size for the ima-kexec buffer */
>>> -	if (!tmp_size)
>>> +	/* Do some sanity on the returned size for the kexec buffer */
>>> +	if (!*size)
>>>   		return -ENOENT;
>>>   
>>>   	/*
>>>   	 * Calculate the PFNs for the buffer and ensure
>>>   	 * they are with in addressable memory.
>>>   	 */
>>> -	start_pfn = PHYS_PFN(tmp_addr);
>>> -	end_pfn = PHYS_PFN(tmp_addr + tmp_size - 1);
>>> +	start_pfn = PHYS_PFN(*addr);
>>> +	end_pfn = PHYS_PFN(*addr + *size - 1);
>>>   	if (!page_is_ram(start_pfn) || !page_is_ram(end_pfn)) {
>>> -		pr_warn("IMA buffer at 0x%lx, size = 0x%zx beyond memory\n",
>>> -			tmp_addr, tmp_size);
>>> +		pr_warn("%s buffer at 0x%lx, size = 0x%zx beyond memory\n",
>>> +			name, *addr, *size);
>>>   		return -EINVAL;
>>>   	}
>>>   
>>> +	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;
>>> +	unsigned long tmp_addr;
>>> +	size_t tmp_size;
>>> +
>>> +	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
>>> +		return -ENOTSUPP;
>>> +
>>> +	ret = get_kexec_buffer("linux,ima-kexec-buffer", &tmp_addr, &tmp_size);
>>> +	if (ret)
>>> +		return ret;
>>> +
>>>   	*addr = __va(tmp_addr);
>>>   	*size = tmp_size;
>>>   
>>> @@ -191,72 +202,82 @@ int ima_free_kexec_buffer(void)
>>>   	return memblock_phys_free(addr, size);
>>>   }
>>>   
>>> -/**
>>> - * remove_ima_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.
>>> - */
>>> -static void remove_ima_buffer(void *fdt, int chosen_node)
>>> +static int remove_buffer(void *fdt, int chosen_node, const char *name)
>>>   {
>>>   	int ret, len;
>>>   	unsigned long addr;
>>>   	size_t size;
>>>   	const void *prop;
>>>   
>>> -	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
>>> -		return;
>>> -
>>> -	prop = fdt_getprop(fdt, chosen_node, "linux,ima-kexec-buffer", &len);
>>> +	prop = fdt_getprop(fdt, chosen_node, name, &len);
>>>   	if (!prop)
>>> -		return;
>>> +		return -ENOENT;
>>>   
>>>   	ret = do_get_kexec_buffer(prop, len, &addr, &size);
>>> -	fdt_delprop(fdt, chosen_node, "linux,ima-kexec-buffer");
>>> +	fdt_delprop(fdt, chosen_node, name);
>>>   	if (ret)
>>> -		return;
>>> +		return ret;
>>>   
>>>   	ret = fdt_find_and_del_mem_rsv(fdt, addr, size);
>>>   	if (!ret)
>>> -		pr_debug("Removed old IMA buffer reservation.\n");
>>> +		pr_debug("Remove old %s buffer reserveration", name);
>>> +	return ret;
>>>   }
>>>   
>>> -#ifdef CONFIG_IMA_KEXEC
>>>   /**
>>> - * 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.
>>> + * remove_ima_buffer - remove the IMA buffer property and reservation from @fdt
>>>    *
>>> - * Return: 0 on success, or negative errno on error.
>>> + * @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.
>>>    */
>>> -static int setup_ima_buffer(const struct kimage *image, void *fdt,
>>> -			    int chosen_node)
>>> +static void remove_ima_buffer(void *fdt, int chosen_node)
>>> +{
>>> +	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
>>> +		return;
>>> +
>>> +	remove_buffer(fdt, chosen_node, "linux,ima-kexec-buffer");
>>> +}
>>> +
>>> +#ifdef CONFIG_IMA_KEXEC
>>> +static int setup_buffer(void *fdt, int chosen_node, const char *name,
>>> +			phys_addr_t addr, size_t size)
>>>   {
>>>   	int ret;
>>>   
>>> -	if (!image->ima_buffer_size)
>>> +	if (!size)
>>>   		return 0;
>>>   
>>>   	ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
>>> -				       "linux,ima-kexec-buffer",
>>> -				       image->ima_buffer_addr,
>>> -				       image->ima_buffer_size);
>>> +				       name, addr, size);
>>>   	if (ret < 0)
>>>   		return -EINVAL;
>>>   
>>> -	ret = fdt_add_mem_rsv(fdt, image->ima_buffer_addr,
>>> -			      image->ima_buffer_size);
>>> +	ret = fdt_add_mem_rsv(fdt, addr, size);
>>>   	if (ret)
>>>   		return -EINVAL;
>>>   
>>> -	pr_debug("IMA buffer at 0x%pa, size = 0x%zx\n",
>>> -		 &image->ima_buffer_addr, image->ima_buffer_size);
>>> +	pr_debug("%s at 0x%pa, size = 0x%zx\n", name, &addr, size);
>>>   
>>>   	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.
>>> + */
>>> +static int setup_ima_buffer(const struct kimage *image, void *fdt,
>>> +			    int chosen_node)
>>> +{
>>> +	return setup_buffer(fdt, chosen_node, "linux,ima-kexec-buffer",
>>> +			    image->ima_buffer_addr, image->ima_buffer_size);
>>>   }
>>>   #else /* CONFIG_IMA_KEXEC */
>>>   static inline int setup_ima_buffer(const struct kimage *image, void *fdt,