[PATCH 5.15] of: kexec: Mark ima_{free,stable}_kexec_buffer() as __init

[Nathan Chancellor <nathan@xxxxxxxxxx>]

This commit has no direct upstream equivalent.

After commit d48016d74836 ("mm,ima,kexec,of: use memblock_free_late from
ima_free_kexec_buffer") in 5.15, there is a modpost warning for certain
configurations:

  WARNING: modpost: vmlinux.o(.text+0xb14064): Section mismatch in reference from the function ima_free_kexec_buffer() to the function .init.text:__memblock_free_late()
  The function ima_free_kexec_buffer() references
  the function __init __memblock_free_late().
  This is often because ima_free_kexec_buffer lacks a __init
  annotation or the annotation of __memblock_free_late is wrong.

In mainline, there is no issue because ima_free_kexec_buffer() is marked
as __init, which was done as part of commit b69a2afd5afc ("x86/kexec:
Carry forward IMA measurement log on kexec") in 6.0, which is not
suitable for stable.

Mark ima_free_kexec_buffer() and its single caller
ima_load_kexec_buffer() as __init in 5.15, as ima_load_kexec_buffer() is
only called from ima_init(), which is __init, clearing up the warning.

Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
---
 drivers/of/kexec.c                 | 2 +-
 include/linux/of.h                 | 2 +-
 security/integrity/ima/ima.h       | 2 +-
 security/integrity/ima/ima_kexec.c | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index 3a07cc58e7d7..d10fd54415c2 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -165,7 +165,7 @@ int ima_get_kexec_buffer(void **addr, size_t *size)
 /**
  * ima_free_kexec_buffer - free memory used by the IMA buffer
  */
-int ima_free_kexec_buffer(void)
+int __init ima_free_kexec_buffer(void)
 {
 	int ret;
 	unsigned long addr;
diff --git a/include/linux/of.h b/include/linux/of.h
index 140671cb746a..6f15e8b0f9d1 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -574,7 +574,7 @@ void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
 				   unsigned long initrd_len,
 				   const char *cmdline, size_t extra_fdt_size);
 int ima_get_kexec_buffer(void **addr, size_t *size);
-int ima_free_kexec_buffer(void);
+int __init ima_free_kexec_buffer(void);
 #else /* CONFIG_OF */
 
 static inline void of_core_init(void)
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index be965a8715e4..0afe413dda68 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -122,7 +122,7 @@ struct ima_kexec_hdr {
 extern const int read_idmap[];
 
 #ifdef CONFIG_HAVE_IMA_KEXEC
-void ima_load_kexec_buffer(void);
+void __init ima_load_kexec_buffer(void);
 #else
 static inline void ima_load_kexec_buffer(void) {}
 #endif /* CONFIG_HAVE_IMA_KEXEC */
diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c
index f799cc278a9a..f3b10851bbbf 100644
--- a/security/integrity/ima/ima_kexec.c
+++ b/security/integrity/ima/ima_kexec.c
@@ -137,7 +137,7 @@ void ima_add_kexec_buffer(struct kimage *image)
 /*
  * Restore the measurement list from the previous kernel.
  */
-void ima_load_kexec_buffer(void)
+void __init ima_load_kexec_buffer(void)
 {
 	void *kexec_buffer = NULL;
 	size_t kexec_buffer_size = 0;

---
base-commit: 8f790700c974345ab78054e109beddd84539f319
change-id: 20230905-5-15-of-kexec-modpost-warning-6a6b48f30ebf

Best regards,
-- 
Nathan Chancellor <nathan@xxxxxxxxxx>