On 10/20/26 2:07 PM, Roberto Sassu wrote:
From: Roberto Sassu <[email protected]>
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 <[email protected]>
Tested-by: Srish Srinivasan <[email protected]> # PowerVM
---
v2:
- Reworded the commit message (no code changes), suggested by Mimi
arch/arm64/Kconfig | 2 +-
arch/loongarch/Kconfig | 2 +-
arch/powerpc/Kconfig | 2 +-
arch/riscv/Kconfig | 2 +-
arch/x86/kernel/setup.c | 2 +-
drivers/of/kexec.c | 4 ++--
kernel/Kconfig.kexec | 4 ++++
7 files changed, 11 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index b5a51b0ef944..4b7e248b6c91 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1697,7 +1697,7 @@ config ARCH_SUPPORTS_KEXEC_FILE
config ARCH_SELECTS_KEXEC_FILE
def_bool y
depends on KEXEC_FILE
- select HAVE_IMA_KEXEC if IMA
+ select HAVE_IMA_KEXEC_OF if IMA
config ARCH_SUPPORTS_KEXEC_SIG
def_bool y
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index 2067d1f2ad7a..b5420d482da4 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -690,7 +690,7 @@ config ARCH_SELECTS_KEXEC_FILE
depends on KEXEC_FILE
select KEXEC_ELF
select RELOCATABLE
- select HAVE_IMA_KEXEC if IMA
+ select HAVE_IMA_KEXEC_OF if IMA
config ARCH_SUPPORTS_CRASH_DUMP
def_bool 64BIT
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 2580e27e4328..096c6061893b 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -643,7 +643,7 @@ config ARCH_SELECTS_KEXEC_FILE
def_bool y
depends on KEXEC_FILE
select KEXEC_ELF
- select HAVE_IMA_KEXEC if IMA
+ select HAVE_IMA_KEXEC_OF if IMA
config PPC64_BIG_ENDIAN_ELF_ABI_V2
# Option is available to BFD, but LLD does not support ELFv1 so this is
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index f8e26c4bed2b..161bf8a65beb 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -1118,7 +1118,7 @@ config ARCH_SUPPORTS_KEXEC_FILE
config ARCH_SELECTS_KEXEC_FILE
def_bool y
depends on KEXEC_FILE
- select HAVE_IMA_KEXEC if IMA
+ select HAVE_IMA_KEXEC_OF if IMA
select KEXEC_ELF
config ARCH_SUPPORTS_KEXEC_PURGATORY
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index cda6adb9f69c..bc17e353c099 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -421,7 +421,7 @@ static void __init add_early_ima_buffer(u64 phys_addr)
#endif
}
-#if defined(CONFIG_HAVE_IMA_KEXEC) && !defined(CONFIG_OF_FLATTREE)
+#ifdef CONFIG_HAVE_IMA_KEXEC
int __init ima_free_kexec_buffer(void)
{
if (!ima_kexec_buffer_size)
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index 029903b986cb..724f29fef0c0 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -116,7 +116,7 @@ static int do_get_kexec_buffer(const void *prop, int len,
unsigned long *addr,
return 0;
}
-#ifdef CONFIG_HAVE_IMA_KEXEC
+#ifdef CONFIG_HAVE_IMA_KEXEC_OF
/**
* ima_get_kexec_buffer - get IMA buffer from the previous kernel
* @addr: On successful return, set to point to the buffer contents.
@@ -196,7 +196,7 @@ static void remove_ima_buffer(void *fdt, int chosen_node)
size_t size;
const void *prop;
- if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
+ if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC_OF))
return;
prop = fdt_getprop(fdt, chosen_node, "linux,ima-kexec-buffer", &len);
diff --git a/kernel/Kconfig.kexec b/kernel/Kconfig.kexec
index 15632358bcf7..c6ed60f04ea4 100644
--- a/kernel/Kconfig.kexec
+++ b/kernel/Kconfig.kexec
@@ -17,6 +17,10 @@ config KEXEC_ELF
config HAVE_IMA_KEXEC
bool
+config HAVE_IMA_KEXEC_OF
+ bool
+ select HAVE_IMA_KEXEC
+
config KEXEC
bool "Enable kexec system call"
depends on ARCH_SUPPORTS_KEXEC
