From: Stanislav Kinsburskii <stanislav.kinsburskii@xxxxxxxxx>
Introduce primitives to:
- Register and unregister callbacks for flattened device tree (fdt)
modifications.
- Invoke all registered callbacks.
- Check for any registered callbacks.
These enhancements enable the use of a device tree to store kernel bits.
Signed-off-by: Stanislav Kinsburskii <skinsburskii@xxxxxxxxxxxxxxxxxxx>
---
include/linux/kexec.h | 7 +++++++
kernel/kexec_file.c | 24 ++++++++++++++++++++++++
2 files changed, 31 insertions(+)
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 22b5cd24f581..c9c70551796d 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -282,6 +282,13 @@ arch_kexec_apply_relocations(struct purgatory_info *pi, Elf_Shdr *section,
return -ENOEXEC;
}
#endif
+
+struct notifier_block;
+extern int register_kexec_fdt_notifier(struct notifier_block *nb);
+extern int unregister_kexec_fdt_notifier(struct notifier_block *nb);
+extern bool kexec_fdt_notify_list_empty(void);
+extern int kexec_fdt_notify(void *fdt);
+
#endif /* CONFIG_KEXEC_FILE */
#ifdef CONFIG_KEXEC_ELF
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 881ba0d1714c..f9245d5e4459 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -43,6 +43,30 @@ static int kexec_calculate_store_digests(struct kimage *image);
/* Maximum size in bytes for kernel/initrd files. */
#define KEXEC_FILE_SIZE_MAX min_t(s64, 4LL << 30, SSIZE_MAX)
+static BLOCKING_NOTIFIER_HEAD(kexec_fdt_notify_list);
+
+bool kexec_fdt_notify_list_empty(void)
+{
+ return kexec_fdt_notify_list.head == NULL;
+}
+
+int kexec_fdt_notify(void *fdt)
+{
+ return blocking_notifier_call_chain(&kexec_fdt_notify_list, 0, fdt);
+}
+
+int register_kexec_fdt_notifier(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_register(&kexec_fdt_notify_list, nb);
+}
+EXPORT_SYMBOL(register_kexec_fdt_notifier);
+
+int unregister_kexec_fdt_notifier(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_unregister(&kexec_fdt_notify_list, nb);
+}
+EXPORT_SYMBOL(unregister_kexec_fdt_notifier);
+
/*
* Currently this is the only default function that is exported as some
* architectures need it to do additional handlings.
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