From: Olivier Houchard <ohouchard@haproxy.com>
Date: Wed, 28 Oct 2026 17:51:13 +0000 (+0100)
Subject: MINOR: sym: use the symbol table to resolve a DSO name
X-Git-Tag: v3.5-dev11~93
X-Git-Url: https://git.kaiwu.me/?a=commitdiff_plain;h=e596dcdca89c04cd8ed53d4f8c4004aa824fb3b2;p=haproxy.git

MINOR: sym: use the symbol table to resolve a DSO name

resolve_dso_name() only used dladdr() to find the object containing an
address. Our in-process symbol table also knows the owning object, is
lock-free and async-signal-safe, and also works on static builds where
dladdr() may not. Try it first and keep dladdr() as a fallback for
addresses that are not covered by any symbol, or when the table has not
been built yet.
---

diff --git a/src/sym.c b/src/sym.c
index a3fe65d48..412c82caf 100644
--- a/src/sym.c
+++ b/src/sym.c
@@ -1854,21 +1854,29 @@ const void *resolve_sym_name(struct buffer *buf, const char *pfx, const void *ad
  */
 const void *resolve_dso_name(struct buffer *buf, const char *pfx, const void *addr)
 {
+	struct sym_lookup sl;
+
+	if (sym_resolve(addr, &sl) && sl.file) {
+		if (pfx)
+			chunk_appendf(buf, "%s", pfx);
+		append_obj_name(buf, sl.file);
+		return addr;
+	}
+
 #if (defined(__ELF__) && !defined(__linux__)) || defined(USE_DL)
-	Dl_info dli;
-	size_t size;
+	{
+		Dl_info dli;
+		size_t size;
 
-	/* Now let's try to be smarter */
-	if (!dladdr_and_size(addr, &dli, &size))
-		goto unknown;
+		/* Now let's try to be smarter */
+		if (!dladdr_and_size(addr, &dli, &size))
+			goto unknown;
 
-	if (pfx) {
-		chunk_appendf(buf, "%s", pfx);
-		pfx = NULL;
+		if (pfx)
+			chunk_appendf(buf, "%s", pfx);
+		append_obj_name(buf, dli.dli_fname);
+		return addr;
 	}
-
-	append_obj_name(buf, dli.dli_fname);
-	return addr;
  unknown:
 #endif /* __ELF__ && !__linux__ || USE_DL */