diff mbox series

[v8,2/4] powerpc: Refactor kexec functions to move arch independent code to ima

Message ID 20201030174429.29893-3-nramas@linux.microsoft.com (mailing list archive)
State New, archived
Headers show
Series Carry forward IMA measurement log on kexec on ARM64 | expand

Commit Message

Lakshmi Ramasubramanian Oct. 30, 2020, 5:44 p.m. UTC
The functions ima_get_kexec_buffer() and ima_free_kexec_buffer(),
that handle carrying forward the IMA measurement logs on kexec for
powerpc do not have architecture specific code, but they are currently
defined for powerpc only.

Move ima_get_kexec_buffer() and ima_free_kexec_buffer() to IMA
subsystem. A later patch in this series will use these functions for
carrying forward the IMA measurement log for ARM64.

With the above refactoring arch/powerpc/kexec/ima.c contains only
functions used when CONFIG_IMA_KEXEC is enabled. Update Makefile
in arch/powerpc/kexec to include arch/powerpc/kexec/ima.c only
when CONFIG_IMA_KEXEC is enabled.

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>
---
 arch/powerpc/include/asm/ima.h     |  3 --
 arch/powerpc/kexec/Makefile        |  7 +---
 arch/powerpc/kexec/ima.c           | 56 -----------------------------
 security/integrity/ima/ima_kexec.c | 57 ++++++++++++++++++++++++++++++
 4 files changed, 58 insertions(+), 65 deletions(-)

Comments

Mimi Zohar Nov. 3, 2020, 2:55 p.m. UTC | #1
Hi Lakshmi,

On Fri, 2020-10-30 at 10:44 -0700, Lakshmi Ramasubramanian wrote:
> The functions ima_get_kexec_buffer() and ima_free_kexec_buffer(),
> that handle carrying forward the IMA measurement logs on kexec for
> powerpc do not have architecture specific code, but they are currently
> defined for powerpc only.
> 
> Move ima_get_kexec_buffer() and ima_free_kexec_buffer() to IMA
> subsystem. A later patch in this series will use these functions for
> carrying forward the IMA measurement log for ARM64.
> 
> With the above refactoring arch/powerpc/kexec/ima.c contains only
> functions used when CONFIG_IMA_KEXEC is enabled. Update Makefile
> in arch/powerpc/kexec to include arch/powerpc/kexec/ima.c only
> when CONFIG_IMA_KEXEC is enabled.
> 
> 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>

Similar comments to 1/4.
-  Last line of first paragraph can be rephrased like " ... on kexec,
do not contain architecture specific code, but are currently limited to
powerpc."
-  This patch should be limited to moving existing functions.  
Truncate the Subject line to "Move arch independent IMA kexec functions
to ima_kexec.c."
- Don't refer to a later patch, but explain the purpose here.  For
example, "Move ... , making them accessible to other archs."
- The definition of "FDT_PROP_IMA_KEXEC_BUFFER" should be made as a
separate, prepartory patch, prior to the existing 1/4.  The resulting
code being moved in this patch (and similarly for 1/4) will be exactly
the same as the code being deleted.

thanks,

Mimi
Lakshmi Ramasubramanian Nov. 3, 2020, 7:23 p.m. UTC | #2
On 11/3/20 6:55 AM, Mimi Zohar wrote:

Hi Mimi,

> 
> On Fri, 2020-10-30 at 10:44 -0700, Lakshmi Ramasubramanian wrote:
>> The functions ima_get_kexec_buffer() and ima_free_kexec_buffer(),
>> that handle carrying forward the IMA measurement logs on kexec for
>> powerpc do not have architecture specific code, but they are currently
>> defined for powerpc only.
>>
>> Move ima_get_kexec_buffer() and ima_free_kexec_buffer() to IMA
>> subsystem. A later patch in this series will use these functions for
>> carrying forward the IMA measurement log for ARM64.
>>
>> With the above refactoring arch/powerpc/kexec/ima.c contains only
>> functions used when CONFIG_IMA_KEXEC is enabled. Update Makefile
>> in arch/powerpc/kexec to include arch/powerpc/kexec/ima.c only
>> when CONFIG_IMA_KEXEC is enabled.
>>
>> 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>
> 
> Similar comments to 1/4.
> -  Last line of first paragraph can be rephrased like " ... on kexec,
> do not contain architecture specific code, but are currently limited to
> powerpc."
Sure.

> -  This patch should be limited to moving existing functions.
> Truncate the Subject line to "Move arch independent IMA kexec functions
> to ima_kexec.c."
Will do.

> - Don't refer to a later patch, but explain the purpose here.  For
> example, "Move ... , making them accessible to other archs."
Sure.

> - The definition of "FDT_PROP_IMA_KEXEC_BUFFER" should be made as a
> separate, prepartory patch, prior to the existing 1/4.  The resulting
> code being moved in this patch (and similarly for 1/4) will be exactly
> the same as the code being deleted.

Definition of FDT_PROP_IMA_KEXEC_BUFFER will be made as a preparatory 
patch as you'd mentioned in the comments for [PATCH 1/4].

Will split [PATCH 2/4] as listed below:

PATCH #1: Move ima_get_kexec_buffer() and ima_free_kexec_buffer() to 
IMA, along with deleting them in arch/powerpc/kexec/ima.c

PATCH #2: Update arch/powerpc/kexec/Makefile and
           arch/powerpc/kexec/ima.c
           to compile when CONFIG_IMA_KEXEC is defined.

thanks,
  -lakshmi
Mimi Zohar Nov. 3, 2020, 7:50 p.m. UTC | #3
On Tue, 2020-11-03 at 11:23 -0800, Lakshmi Ramasubramanian wrote:
> On 11/3/20 6:55 AM, Mimi Zohar wrote:
> 
> Hi Mimi,
> 
> > 
> > On Fri, 2020-10-30 at 10:44 -0700, Lakshmi Ramasubramanian wrote:
> >> The functions ima_get_kexec_buffer() and ima_free_kexec_buffer(),
> >> that handle carrying forward the IMA measurement logs on kexec for
> >> powerpc do not have architecture specific code, but they are currently
> >> defined for powerpc only.
> >>
> >> Move ima_get_kexec_buffer() and ima_free_kexec_buffer() to IMA
> >> subsystem. A later patch in this series will use these functions for
> >> carrying forward the IMA measurement log for ARM64.
> >>
> >> With the above refactoring arch/powerpc/kexec/ima.c contains only
> >> functions used when CONFIG_IMA_KEXEC is enabled. Update Makefile
> >> in arch/powerpc/kexec to include arch/powerpc/kexec/ima.c only
> >> when CONFIG_IMA_KEXEC is enabled.
> >>
> >> 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>
> > 
> > Similar comments to 1/4.
> > -  Last line of first paragraph can be rephrased like " ... on kexec,
> > do not contain architecture specific code, but are currently limited to
> > powerpc."
> Sure.
> 
> > -  This patch should be limited to moving existing functions.
> > Truncate the Subject line to "Move arch independent IMA kexec functions
> > to ima_kexec.c."
> Will do.
> 
> > - Don't refer to a later patch, but explain the purpose here.  For
> > example, "Move ... , making them accessible to other archs."
> Sure.
> 
> > - The definition of "FDT_PROP_IMA_KEXEC_BUFFER" should be made as a
> > separate, prepartory patch, prior to the existing 1/4.  The resulting
> > code being moved in this patch (and similarly for 1/4) will be exactly
> > the same as the code being deleted.
> 
> Definition of FDT_PROP_IMA_KEXEC_BUFFER will be made as a preparatory 
> patch as you'd mentioned in the comments for [PATCH 1/4].
> 
> Will split [PATCH 2/4] as listed below:
> 
> PATCH #1: Move ima_get_kexec_buffer() and ima_free_kexec_buffer() to 
> IMA, along with deleting them in arch/powerpc/kexec/ima.c

No, other than the comments above, this patch is fine.  It moves
ima_get_kexec_buffer() and ima_free_kexec_buffer() to ima_kexec.c.

Mimi
Lakshmi Ramasubramanian Nov. 3, 2020, 8:05 p.m. UTC | #4
On 11/3/20 11:50 AM, Mimi Zohar wrote:
> On Tue, 2020-11-03 at 11:23 -0800, Lakshmi Ramasubramanian wrote:
>> On 11/3/20 6:55 AM, Mimi Zohar wrote:
>>
>> Hi Mimi,
>>
>>>
>>> On Fri, 2020-10-30 at 10:44 -0700, Lakshmi Ramasubramanian wrote:
>>>> The functions ima_get_kexec_buffer() and ima_free_kexec_buffer(),
>>>> that handle carrying forward the IMA measurement logs on kexec for
>>>> powerpc do not have architecture specific code, but they are currently
>>>> defined for powerpc only.
>>>>
>>>> Move ima_get_kexec_buffer() and ima_free_kexec_buffer() to IMA
>>>> subsystem. A later patch in this series will use these functions for
>>>> carrying forward the IMA measurement log for ARM64.
>>>>
>>>> With the above refactoring arch/powerpc/kexec/ima.c contains only
>>>> functions used when CONFIG_IMA_KEXEC is enabled. Update Makefile
>>>> in arch/powerpc/kexec to include arch/powerpc/kexec/ima.c only
>>>> when CONFIG_IMA_KEXEC is enabled.
>>>>
>>>> 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>
>>>
>>> Similar comments to 1/4.
>>> -  Last line of first paragraph can be rephrased like " ... on kexec,
>>> do not contain architecture specific code, but are currently limited to
>>> powerpc."
>> Sure.
>>
>>> -  This patch should be limited to moving existing functions.
>>> Truncate the Subject line to "Move arch independent IMA kexec functions
>>> to ima_kexec.c."
>> Will do.
>>
>>> - Don't refer to a later patch, but explain the purpose here.  For
>>> example, "Move ... , making them accessible to other archs."
>> Sure.
>>
>>> - The definition of "FDT_PROP_IMA_KEXEC_BUFFER" should be made as a
>>> separate, prepartory patch, prior to the existing 1/4.  The resulting
>>> code being moved in this patch (and similarly for 1/4) will be exactly
>>> the same as the code being deleted.
>>
>> Definition of FDT_PROP_IMA_KEXEC_BUFFER will be made as a preparatory
>> patch as you'd mentioned in the comments for [PATCH 1/4].
>>
>> Will split [PATCH 2/4] as listed below:
>>
>> PATCH #1: Move ima_get_kexec_buffer() and ima_free_kexec_buffer() to
>> IMA, along with deleting them in arch/powerpc/kexec/ima.c
> 
> No, other than the comments above, this patch is fine.  It moves
> ima_get_kexec_buffer() and ima_free_kexec_buffer() to ima_kexec.c.
> 

Ok - I will do the updates in the patch description only and keep the 
code changes as is. Thanks for clarifying.

  -lakshmi
diff mbox series

Patch

diff --git a/arch/powerpc/include/asm/ima.h b/arch/powerpc/include/asm/ima.h
index 6355a85a3289..8975f5e0cab8 100644
--- a/arch/powerpc/include/asm/ima.h
+++ b/arch/powerpc/include/asm/ima.h
@@ -6,9 +6,6 @@ 
 
 struct kimage;
 
-int ima_get_kexec_buffer(void **addr, size_t *size);
-int ima_free_kexec_buffer(void);
-
 #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/Makefile b/arch/powerpc/kexec/Makefile
index 4aff6846c772..f54a9dbff4c8 100644
--- a/arch/powerpc/kexec/Makefile
+++ b/arch/powerpc/kexec/Makefile
@@ -9,12 +9,7 @@  obj-$(CONFIG_PPC32)		+= relocate_32.o
 
 obj-$(CONFIG_KEXEC_FILE)	+= file_load.o ranges.o file_load_$(BITS).o elf_$(BITS).o
 
-ifdef CONFIG_HAVE_IMA_KEXEC
-ifdef CONFIG_IMA
-obj-y				+= ima.o
-endif
-endif
-
+obj-$(CONFIG_IMA_KEXEC)		+= ima.o
 
 # Disable GCOV, KCOV & sanitizers in odd or sensitive code
 GCOV_PROFILE_core_$(BITS).o := n
diff --git a/arch/powerpc/kexec/ima.c b/arch/powerpc/kexec/ima.c
index 2b790230ea15..4fadd8d16891 100644
--- a/arch/powerpc/kexec/ima.c
+++ b/arch/powerpc/kexec/ima.c
@@ -30,61 +30,6 @@  static int get_addr_size_cells(int *addr_cells, int *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);
-
-}
-
-#ifdef CONFIG_IMA_KEXEC
 /**
  * arch_ima_add_kexec_buffer - do arch-specific steps to add the IMA buffer
  *
@@ -177,4 +122,3 @@  int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node)
 
 	return 0;
 }
-#endif /* CONFIG_IMA_KEXEC */
diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c
index 121de3e04af2..24be285ec558 100644
--- a/security/integrity/ima/ima_kexec.c
+++ b/security/integrity/ima/ima_kexec.c
@@ -10,8 +10,65 @@ 
 #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 <linux/ima.h>
 #include "ima.h"
 
+/**
+ * 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.
+ */
+static 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, FDT_PROP_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
+ */
+static int ima_free_kexec_buffer(void)
+{
+	int ret;
+	unsigned long addr;
+	size_t size;
+	struct property *prop;
+
+	prop = of_find_property(of_chosen, FDT_PROP_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);
+}
+
+
 #ifdef CONFIG_IMA_KEXEC
 static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer,
 				     unsigned long segment_size)