[osv-dev] [PATCH 2/3] look up symbol deeper

[Zhiting Zhu]

Signed-off-by: Zhiting Zhu <zhiti...@cs.utexas.edu>
---
 core/elf.cc        | 14 ++++++++++++++
 include/osv/elf.hh |  1 +
 libc/dlfcn.cc      |  2 +-
 tests/tst-dlfcn.cc |  2 +-
 4 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/core/elf.cc b/core/elf.cc
index 31777b92..882b4d49 100644
--- a/core/elf.cc
+++ b/core/elf.cc
@@ -917,6 +917,20 @@ Elf64_Sym* object::lookup_symbol(const char* name)
     return sym;
 }
 
+symbol_module object::lookup_symbol_deep(const char* name)
+{
+    symbol_module sym = { lookup_symbol(name), this };
+    if (!sym.symbol) {
+        for (auto&& _obj : _needed) {
+            sym = _obj->lookup_symbol_deep(name);
+            if (sym.symbol) {
+                break;
+            }
+        }
+    }
+    return sym;
+}
+
 unsigned object::symtab_len()
 {
     if (dynamic_exists(DT_HASH)) {
diff --git a/include/osv/elf.hh b/include/osv/elf.hh
index 8e37aebb..ededb75a 100644
--- a/include/osv/elf.hh
+++ b/include/osv/elf.hh
@@ -341,6 +341,7 @@ public:
     void* base() const;
     void* end() const;
     Elf64_Sym* lookup_symbol(const char* name);
+    symbol_module lookup_symbol_deep(const char* name);
     void load_segments();
     void unload_segments();
     void fix_permissions();
diff --git a/libc/dlfcn.cc b/libc/dlfcn.cc
index 8cfb7b2a..1cad7ffd 100644
--- a/libc/dlfcn.cc
+++ b/libc/dlfcn.cc
@@ -74,7 +74,7 @@ void* dlsym(void* handle, const char* name)
         abort();
     } else {
         auto obj = *reinterpret_cast<std::shared_ptr<elf::object>*>(handle);
-        sym = { obj->lookup_symbol(name), obj.get() };
+        sym = obj->lookup_symbol_deep(name);
     }
     if (!sym.obj || !sym.symbol) {
         dlerror_fmt("dlsym: symbol %s not found", name);
diff --git a/tests/tst-dlfcn.cc b/tests/tst-dlfcn.cc
index d2c9f288..614a3d00 100644
--- a/tests/tst-dlfcn.cc
+++ b/tests/tst-dlfcn.cc
@@ -13,7 +13,7 @@
 namespace utf = boost::unit_test;
 
 const bool rtld_next = false;
-const bool deep_lookup = false;
+const bool deep_lookup = true;
 
 static bool called = false;
 extern "C" void DlSymTestFunction()
-- 
2.17.1

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