From 9768162c5ba7c362d07748d8f0fcbb8b95a39cb9 Mon Sep 17 00:00:00 2001
From: James Cuzella <james.cuzella@lyraphase.com>
Date: Sun, 15 Sep 2024 10:08:38 -0600
Subject: [PATCH] Fix #574 - Revert "Improve compatibility of binfmt-bypass
 with really old Docker images"

This reverts commit c810e7070e70e735edbd4be3e8e932e4e3f1a666.

Notes:

- [CentOS 7 reached End of Life][1] on June 30, 2024
- [RedHat moved CentOS Stream 8 & 9 upstream of RHEL][2]
- Arch Linux & Manjaro unstable channel have GlibC with symbol version `2.14`:

    U memcpy@GLIBC_2.14

[1]: https://www.redhat.com/en/topics/linux/centos-linux-eol
[2]: https://www.theregister.com/2023/06/23/red_hat_centos_move/
---
 src/binfmt-bypass/CMakeLists.txt         | 33 +++++++++-------------
 src/binfmt-bypass/fix-preload-library.sh | 35 ------------------------
 2 files changed, 13 insertions(+), 55 deletions(-)
 delete mode 100644 src/binfmt-bypass/fix-preload-library.sh

diff --git a/src/binfmt-bypass/CMakeLists.txt b/src/binfmt-bypass/CMakeLists.txt
index 87773fdd..c3376d22 100644
--- a/src/binfmt-bypass/CMakeLists.txt
+++ b/src/binfmt-bypass/CMakeLists.txt
@@ -56,15 +56,6 @@ function(make_preload_lib_target target_name)
         # hide all symbols by default
         -fvisibility=hidden
     )
-
-    # a bit of a hack, but it seems to make binfmt bypass work in really old Docker images (e.g., CentOS <= 7)
-    add_custom_command(
-        TARGET ${target_name}
-        POST_BUILD
-        COMMAND bash ${CMAKE_CURRENT_SOURCE_DIR}/fix-preload-library.sh $<TARGET_FILE_NAME:${target_name}>
-        WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
-        VERBATIM
-    )
 endfunction()
 
 make_preload_lib_target(${preload_lib})
@@ -95,21 +86,23 @@ endif()
 # this is a workaround to existing issues using AppImages in Docker with AppImageLauncher installed on the host system
 check_program(NAME xxd)
 
-function(generate_preload_lib_header target_name)
+add_custom_command(
+    OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${preload_lib}.h
+    COMMAND xxd -i $<TARGET_FILE_NAME:${preload_lib}> ${preload_lib}.h
+    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+    DEPENDS ${preload_lib}
+    VERBATIM
+)
+
+# same story for 32-bit lib
+if (build_32bit_preload_library)
     add_custom_command(
-        OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${target_name}.h
-        COMMAND xxd -i $<TARGET_FILE_NAME:${target_name}> ${target_name}.h
+        OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${preload_lib_32bit}.h
+        COMMAND xxd -i $<TARGET_FILE_NAME:${preload_lib_32bit}> ${preload_lib_32bit}.h
         WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
-        DEPENDS ${target_name}
+        DEPENDS ${preload_lib_32bit}
         VERBATIM
     )
-endfunction()
-
-generate_preload_lib_header(${preload_lib})
-
-# same story for 32-bit lib
-if (build_32bit_preload_library)
-    generate_preload_lib_header(${preload_lib_32bit})
 endif()
 
 # the lib provides an algorithm to extract the runtime, patch it and launch it, preloading our preload lib to make the
diff --git a/src/binfmt-bypass/fix-preload-library.sh b/src/binfmt-bypass/fix-preload-library.sh
deleted file mode 100644
index e3258f34..00000000
--- a/src/binfmt-bypass/fix-preload-library.sh
+++ /dev/null
@@ -1,35 +0,0 @@
-#! /bin/bash
-
-set -euo pipefail
-
-glibc_ok_version="2.4"
-
-find_too_new_symbols() {
-    glibc_symbols=( "$(nm --dynamic --undefined-only --with-symbol-versions "$1" | grep "GLIBC_")" )
-
-    for glibc_symbol in "${glibc_symbols[@]}"; do
-        # shellcheck disable=SC2001
-        glibc_symbol_version="$(sed 's|.*GLIBC_\([\.0-9]\+\)$|\1|' <<< "$glibc_symbol")"
-        newest_glibc_symbol_version="$(echo -e "$glibc_ok_version\\n$glibc_symbol_version" | sort -V | tail -n1)"
-
-        # make sure the newest version found is <= the one we define as ok
-        if [[ "$newest_glibc_symbol_version" == "$glibc_ok_version" ]]; then
-            return 1
-        fi
-    done
-
-    return 0
-}
-
-for file in "$@"; do
-    # obviously, this is a hack, but it should work well enough since we just need to do it for one single symbol from libdl
-    patchelf --debug --clear-symbol-version dlsym "$file"
-
-    nm_data="$(nm --dynamic --undefined-only --with-symbol-versions "$file")"
-
-    if find_too_new_symbols "$file"; then
-        echo "Error: found symbol version markers newer than $glibc_ok_version:"
-        echo "$nm_data"
-        exit 1
-    fi
-done