From 1198329b922f3cdddc3e87a7c81d7730b646c088 Mon Sep 17 00:00:00 2001 From: Yuta Hayama Date: Fri, 28 Jul 2023 16:22:31 +0900 Subject: [PATCH] align startOffset with p_align instead of pagesize for compatibility According to the ELF specification, the alignment of loadable process segments should satisfy (p_vaddr mod pagesize) == (p_offset mod pagesize). However, glibc earlier than 2.35 incorrectly requires that the LOAD segment be (p_vaddr mod p_align) == (p_offset mod p_align), and will output the error message "ELF load command address/offset not properly aligned" if this is not met. Since there are many systems that use glibc earlier than 2.35, it is preferable that newly added LOAD segments satisfy (p_vaddr mod p_align) == (p_offset mod p_align) for compatibility. Signed-off-by: Martin Jansa --- Upstream-Status: Submitted [https://github.com/NixOS/patchelf/pull/510] src/patchelf.cc | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/src/patchelf.cc b/src/patchelf.cc index 82b4b46..6edb81a 100644 --- a/src/patchelf.cc +++ b/src/patchelf.cc @@ -843,7 +843,13 @@ void ElfFile::rewriteSectionsLibrary() neededSpace += headerTableSpace; debug("needed space is %d\n", neededSpace); - Elf_Off startOffset = roundUp(fileContents->size(), getPageSize()); + /* glibc earlier than 2.35 requires that the LOAD segment satisfies + (p_vaddr mod p_align) == (p_offset mod p_align). + The ELF specification requires that loadable process segments satisfy + (p_vaddr mod pagesize) == (p_offset mod pagesize), so glibc is probably + wrong, but here startOffset is calculated according to p_align for + compatibility. */ + Elf_Off startOffset = roundUp(fileContents->size(), alignStartPage); // In older version of binutils (2.30), readelf would check if the dynamic // section segment is strictly smaller than the file (and not same size).