From 98cbcd3ba0b9216a5677271bbf936331644a1218 Mon Sep 17 00:00:00 2001
From: Andrew Gallagher <agallagher@fb.com>
Date: Tue, 31 Oct 2023 11:06:13 -0700
Subject: [PATCH] Don't include undef sym refs when building map of symbol
 definitions

Previously, we'd count undefined symbols references in the map of
symbols defined in a binary, which could cause e.g. py-spy to
misattribute an undefined ref to `_PyRuntime` in some location
other than libpython.so as the definition.
---
 src/binary_parser.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/binary_parser.rs b/src/binary_parser.rs
index 057fed67..356f8354 100644
--- a/src/binary_parser.rs
+++ b/src/binary_parser.rs
@@ -129,10 +129,18 @@ pub fn parse_binary(filename: &Path, addr: u64, size: u64) -> Result<BinaryInfo,
             let offset = offset.saturating_sub(program_header.p_vaddr);
 
             for sym in elf.syms.iter() {
+                // Only count defined symbols.
+                if sym.st_shndx == goblin::elf::section_header::SHN_UNDEF as usize {
+                    continue;
+                }
                 let name = elf.strtab[sym.st_name].to_string();
                 symbols.insert(name, sym.st_value + offset);
             }
             for dynsym in elf.dynsyms.iter() {
+                // Only count defined symbols.
+                if dynsym.st_shndx == goblin::elf::section_header::SHN_UNDEF as usize {
+                    continue;
+                }
                 let name = elf.dynstrtab[dynsym.st_name].to_string();
                 symbols.insert(name, dynsym.st_value + offset);
             }