[PATCH v2] kexec: Select ima_get/free_kexec_buffer() with CONFIG_HAVE_IMA_KEXEC(_OF)

[Catalin Marinas]

On Tue, Oct 20, 2026 at 10:37:27AM +0200, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu at huawei.com>
> 
> On x86, if CONFIG_OF_FLATTREE is enabled, the kernel uses the device tree
> implementation of ima_get/free_kexec_buffer(). However, x86 passes the IMA
> buffer location through setup_data, not through the device tree, so the
> buffer is never found and the IMA measurement list is not carried over
> across kexec.
> 
> Introduce CONFIG_HAVE_IMA_KEXEC_OF (which selects CONFIG_HAVE_IMA_KEXEC)
> and select it for the architectures that pass the IMA buffer location
> through the device tree, via of_kexec_alloc_and_setup_fdt() (arm64,
> powerpc and riscv). Build the device tree implementation of
> ima_get/free_kexec_buffer() only if the new option is enabled.
> 
> Select the new option also on LoongArch, to preserve the current behavior
> and avoid a link failure. LoongArch does not pass the buffer location to
> the next kernel yet; this will be addressed separately.
> 
> Finally, don't select it for x86, and use x86's own setup_data-based
> implementation regardless of CONFIG_OF_FLATTREE.
> 
> Fixes: b69a2afd5afc ("x86/kexec: Carry forward IMA measurement log on kexec")
> Signed-off-by: Roberto Sassu <roberto.sassu at huawei.com>

For arm64:

Acked-by: Catalin Marinas <catalin.marinas at arm.com>