Subject: [PATCH 07/15] bpf: Add bpf_ksym_find function

From: Jiri Olsa <[email-masked]>
Date: Thu, 12 Mar 2020 20:56:02 +0100

Adding bpf_ksym_find function that is used bpf bpf address
lookup functions:
  __bpf_address_lookup
  is_bpf_text_address

while keeping bpf_prog_kallsyms_find to be used only for lookup
of bpf_prog objects (will happen in following changes).

Signed-off-by: Jiri Olsa <[email-masked]>
---
 kernel/bpf/core.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index df0caa4bc9cc..6b58c2f1c9c0 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -668,19 +668,27 @@ static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr)
 	       NULL;
 }
 
+static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
+{
+	struct latch_tree_node *n;
+
+	n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
+	return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
+}
+
 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
 				 unsigned long *off, char *sym)
 {
-	struct bpf_prog *prog;
+	struct bpf_ksym *ksym;
 	char *ret = NULL;
 
 	rcu_read_lock();
-	prog = bpf_prog_kallsyms_find(addr);
-	if (prog) {
-		unsigned long symbol_start = prog->aux->ksym.start;
-		unsigned long symbol_end = prog->aux->ksym.end;
+	ksym = bpf_ksym_find(addr);
+	if (ksym) {
+		unsigned long symbol_start = ksym->start;
+		unsigned long symbol_end = ksym->end;
 
-		strncpy(sym, prog->aux->ksym.name, KSYM_NAME_LEN);
+		strncpy(sym, ksym->name, KSYM_NAME_LEN);
 
 		ret = sym;
 		if (size)
@@ -698,7 +706,7 @@ bool is_bpf_text_address(unsigned long addr)
 	bool ret;
 
 	rcu_read_lock();
-	ret = bpf_prog_kallsyms_find(addr) != NULL;
+	ret = bpf_ksym_find(addr) != NULL;
 	rcu_read_unlock();
 
 	return ret;
-- 
2.24.1