From 65a3453b7f2be6699c632a2f3980e45e960feac8 Mon Sep 17 00:00:00 2001
From: Simon McVittie <[EMAIL REDACTED]>
Date: Thu, 26 May 2022 16:02:15 +0100
Subject: [PATCH] build: Compile with large inode number support where possible
On filesystems with large inode numbers, such as overlayfs, attempting
to stat() a file on a 32-bit system using legacy syscalls can fail
with EOVERFLOW. If we opt-in to more modern "large file support"
syscalls, then source code references to functions like stat() are
transparently replaced with ABIs that support large file sizes and
inode numbers, such as stat64().
This cannot safely be done globally by Linux distributions, because
some libraries expose types like `off_t` or `struct stat` in their
ABI, meaning that enabling large file support would be an incompatible
change that would cause crashes. However, SDL appears to be careful to
avoid these types in header files, so it should be OK to enable this.
Signed-off-by: Simon McVittie <smcv@collabora.com>
---
CMakeLists.txt | 7 +++++++
configure.ac | 1 +
2 files changed, 8 insertions(+)
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8c512bb2924..c988ef56c18 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -56,6 +56,13 @@ set(CMAKE_MODULE_PATH "${SDL2_SOURCE_DIR}/cmake")
include(${SDL2_SOURCE_DIR}/cmake/macros.cmake)
include(${SDL2_SOURCE_DIR}/cmake/sdlchecks.cmake)
+# Enable large file support on 32-bit glibc, so that we can access files
+# with large inode numbers
+check_symbol_exists("__GLIBC__" "stdlib.h" LIBC_IS_GLIBC)
+if (LIBC_IS_GLIBC AND CMAKE_SIZEOF_VOID_P EQUAL 4)
+ add_compile_definitions(PRIVATE _FILE_OFFSET_BITS=64)
+endif()
+
# See docs/release_checklist.md
set(SDL_MAJOR_VERSION 2)
set(SDL_MINOR_VERSION 23)
diff --git a/configure.ac b/configure.ac
index 2686db6b32b..8bba0af0c4c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -60,6 +60,7 @@ dnl AC_CANONICAL_HOST
dnl Check for tools
AC_PROG_CC
AC_PROG_CXX
+AC_SYS_LARGEFILE
AC_PROG_INSTALL
AC_PROG_MAKE_SET
PKG_PROG_PKG_CONFIG