bpf-kallsyms-iterator.patch

From 9c3af2c44583e83444bfd19a45e0beaba4f2e8e6 Mon Sep 17 00:00:00 2001
From: Florian Lehner <dev@der-flo.net>
Date: Wed, 28 Jan 2026 20:05:10 +0100
Subject: [PATCH] kallsyms: TBD

  TBD

Signed-off-by: Florian Lehner <dev@der-flo.net>
---
 include/linux/filter.h |  8 ++++++++
 kernel/bpf/core.c      | 39 +++++++++++++++++++++++++++++++++++++++
 kernel/kallsyms.c      |  8 +++++---
 3 files changed, 52 insertions(+), 3 deletions(-)

diff --git a/include/linux/filter.h b/include/linux/filter.h
index fd54fed8f95f..95fedda5ca9e 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -1380,6 +1380,8 @@ int __bpf_address_lookup(unsigned long addr, unsigned long *size,
 bool is_bpf_text_address(unsigned long addr);
 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 		    char *sym);
+int bpf_get_kallsym_next(void **iter, unsigned long *value, char *type,
+			 char *sym);
 struct bpf_prog *bpf_prog_ksym_find(unsigned long addr);
 
 static inline int
@@ -1448,6 +1450,12 @@ static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value,
 	return -ERANGE;
 }
 
+static inline int bpf_get_kallsym_next(void **iter, unsigned long *value,
+				       char *type, char *sym)
+{
+	return -ERANGE;
+}
+
 static inline struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
 {
 	return NULL;
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 1b9b18e5b03c..52b63f1510bb 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -822,6 +822,45 @@ int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 	return ret;
 }
 
+int bpf_get_kallsym_next(void **iter, unsigned long *value, char *type,
+			 char *sym)
+{
+	struct bpf_ksym *ksym = *iter;
+	struct list_head *head = &bpf_kallsyms;
+	int ret = -ERANGE;
+
+	if (!bpf_jit_kallsyms_enabled())
+		return ret;
+
+	rcu_read_lock();
+
+	if (!ksym) {
+		if (list_empty(head))
+			goto out;
+		ksym = list_first_entry_rcu(head, struct bpf_ksym, lnode);
+	} else {
+		if (list_is_last(&ksym->lnode, head))
+			goto out;
+		ksym = list_next_entry_rcu(ksym, lnode);
+	}
+
+	strscpy(sym, ksym->name, KSYM_NAME_LEN);
+	*value = ksym->start;
+	*type = BPF_SYM_ELF_TYPE;
+
+	*iter = ksym;
+	ret = 0;
+
+out:
+	rcu_read_unlock();
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(bpf_get_kallsym_next);
+
 int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
 				struct bpf_jit_poke_descriptor *poke)
 {
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 049e296f586c..5260b9caf4c4 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -566,6 +566,7 @@ struct kallsym_iter {
 	char module_name[MODULE_NAME_LEN];
 	int exported;
 	int show_value;
+	void *bpf_ksym_iter;
 };
 
 static int get_ksymbol_mod(struct kallsym_iter *iter)
@@ -607,9 +608,9 @@ static int get_ksymbol_bpf(struct kallsym_iter *iter)
 
 	strscpy(iter->module_name, "bpf", MODULE_NAME_LEN);
 	iter->exported = 0;
-	ret = bpf_get_kallsym(iter->pos - iter->pos_ftrace_mod_end,
-			      &iter->value, &iter->type,
-			      iter->name);
+	ret = bpf_get_kallsym_next(&iter->bpf_ksym_iter,
+				   &iter->value, &iter->type,
+				   iter->name);
 	if (ret < 0) {
 		iter->pos_bpf_end = iter->pos;
 		return 0;
@@ -656,6 +657,7 @@ static void reset_iter(struct kallsym_iter *iter, loff_t new_pos)
 		iter->pos_mod_end = 0;
 		iter->pos_ftrace_mod_end = 0;
 		iter->pos_bpf_end = 0;
+		iter->bpf_ksym_iter = NULL;
 	}
 }
 
-- 
2.52.0