Re: [PATCH v12 2/4] powerpc: Move arch independent ima kexec functions to drivers/of/kexec.c

From: Lakshmi Ramasubramanian
Date: Thu Dec 17 2020 - 17:12:12 EST


On 12/17/20 2:01 PM, Rob Herring wrote:
On Thu, Dec 17, 2020 at 2:52 PM Lakshmi Ramasubramanian
<nramas@xxxxxxxxxxxxxxxxxxx> wrote:

On 12/17/20 12:05 PM, Rob Herring wrote:
On Thu, Dec 17, 2020 at 09:37:06AM -0800, Lakshmi Ramasubramanian wrote:
The functions defined in "arch/powerpc/kexec/ima.c" handle setting up
and freeing the resources required to carry over the IMA measurement
list from the current kernel to the next kernel across kexec system call.
These functions do not have architecture specific code, but are
currently limited to powerpc.

[...]

+#ifdef CONFIG_IMA_KEXEC
+/**
+ * arch_ima_add_kexec_buffer - do arch-specific steps to add the IMA buffer
+ *
+ * @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
+ *
+ * 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)

This should be a static inline in asm/kexec.h.

arch_ima_add_kexec_buffer() is identical for powerpc and arm64.
Would it be better to "static inline" this function in "of.h" instead of
duplicating it in "asm/kexec.h" for powerpc and arm64?

No, think about what it is specific to and place it there. It has
nothing to do with DT really. All it is is a wrapper to access the
struct members in kimage_arch. So it belongs where they are declared.
Now perhaps ima_buffer_addr and ima_buffer_size shouldn't be arch
specific, but that's a separate issue.


okay - I'll move arch_ima_add_kexec_buffer() to asm/kexec.h

Please let me know if you have any other comments on the patches.
If you are done reviewing, I'll post the updated patches shortly.

Thanks for reviewing the changes.

-lakshmi