I hit this problem again at work yesterday, so let's fix it. I'm attaching a patch that can be added to the quilt patch stack in our libeigen3-dev package. This disables the conditional preprocessor logic that selects the allocator/deallocator behavior. With this patch we always make no assumptions about the alignment of malloc(), and we ALWAYS use eigen's manual allocator to force alignment. This is maybe a bit less efficient than the other path, but dynamic allocation shouldn't be in any hot code path anyway.
We could also use aligned_alloc() or memalign() instead here, also unconditionally. The "unconditional" is the important part: it must be consistent with any build flags, otherwise stuff can crash. Is this reasonable? Thanks.
Description: https://www.mail-archive.com/debian-science@lists.debian.org/msg13666.html This patch ensures that Eigen memory allocation/free are implemented the same way REGARDLESS of build flags. This ensures that an application using Eigen (possibly indirectly, through libraries) will not crash due to non-identical build flags Author: Dima Kogan <dko...@debian.org> diff --git a/Eigen/src/Core/util/Memory.h b/Eigen/src/Core/util/Memory.h index 875318c..38d55d1 100644 --- a/Eigen/src/Core/util/Memory.h +++ b/Eigen/src/Core/util/Memory.h @@ -17,50 +17,13 @@ *** Platform checks for aligned malloc functions *** *****************************************************************************/ #ifndef EIGEN_MEMORY_H #define EIGEN_MEMORY_H -#ifndef EIGEN_MALLOC_ALREADY_ALIGNED - -// Try to determine automatically if malloc is already aligned. - -// On 64-bit systems, glibc's malloc returns 16-byte-aligned pointers, see: -// http://www.gnu.org/s/libc/manual/html_node/Aligned-Memory-Blocks.html -// This is true at least since glibc 2.8. -// This leaves the question how to detect 64-bit. According to this document, -// http://gcc.fyxm.net/summit/2003/Porting%20to%2064%20bit.pdf -// page 114, "[The] LP64 model [...] is used by all 64-bit UNIX ports" so it's indeed -// quite safe, at least within the context of glibc, to equate 64-bit with LP64. -#if defined(__GLIBC__) && ((__GLIBC__>=2 && __GLIBC_MINOR__ >= 8) || __GLIBC__>2) \ - && defined(__LP64__) && ! defined( __SANITIZE_ADDRESS__ ) && (EIGEN_DEFAULT_ALIGN_BYTES == 16) - #define EIGEN_GLIBC_MALLOC_ALREADY_ALIGNED 1 -#else - #define EIGEN_GLIBC_MALLOC_ALREADY_ALIGNED 0 -#endif - -// FreeBSD 6 seems to have 16-byte aligned malloc -// See http://svn.freebsd.org/viewvc/base/stable/6/lib/libc/stdlib/malloc.c?view=markup -// FreeBSD 7 seems to have 16-byte aligned malloc except on ARM and MIPS architectures -// See http://svn.freebsd.org/viewvc/base/stable/7/lib/libc/stdlib/malloc.c?view=markup -#if defined(__FreeBSD__) && !(EIGEN_ARCH_ARM || EIGEN_ARCH_MIPS) && (EIGEN_DEFAULT_ALIGN_BYTES == 16) - #define EIGEN_FREEBSD_MALLOC_ALREADY_ALIGNED 1 -#else - #define EIGEN_FREEBSD_MALLOC_ALREADY_ALIGNED 0 -#endif - -#if (EIGEN_OS_MAC && (EIGEN_DEFAULT_ALIGN_BYTES == 16)) \ - || (EIGEN_OS_WIN64 && (EIGEN_DEFAULT_ALIGN_BYTES == 16)) \ - || EIGEN_GLIBC_MALLOC_ALREADY_ALIGNED \ - || EIGEN_FREEBSD_MALLOC_ALREADY_ALIGNED - #define EIGEN_MALLOC_ALREADY_ALIGNED 1 -#else - #define EIGEN_MALLOC_ALREADY_ALIGNED 0 -#endif - -#endif +#define EIGEN_MALLOC_ALREADY_ALIGNED 0 namespace Eigen { namespace internal { EIGEN_DEVICE_FUNC
