Add a AC_CHECK_FUNCS configure check for mremap. Some systems like KFreeBSD and the Hurd don't have it. Also add a configure warning because without mremap elf_update will often fail when ELF_C_RDWR_MMAP is used. ELF_C_RDWR_MMAP is an elfutils extension to libelf.
https://sourceware.org/bugzilla/show_bug.cgi?id=27337 Signed-off-by: Mark Wielaard <m...@klomp.org> --- ChangeLog | 4 ++++ configure.ac | 5 ++++- libelf/ChangeLog | 4 ++++ libelf/elf_update.c | 2 ++ 4 files changed, 14 insertions(+), 1 deletion(-) diff --git a/ChangeLog b/ChangeLog index 3357f69b..f0cd28a8 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,7 @@ +2022-04-24 Mark Wielaard <m...@klomp.org> + + * configure.ac (AC_CHECK_FUNCS): Add mremap. + 2021-03-20 Mark Wielaard <m...@klomp.org> * configure.ac: Remove -m64 on 32bit target comments for diff --git a/configure.ac b/configure.ac index 2418d474..33c4b5e5 100644 --- a/configure.ac +++ b/configure.ac @@ -435,7 +435,10 @@ AC_CHECK_DECLS([reallocarray],[],[], [#define _GNU_SOURCE #include <stdlib.h>]) -AC_CHECK_FUNCS([process_vm_readv]) +AC_CHECK_FUNCS([process_vm_readv mremap]) + +AS_IF([test "x$ac_cv_func_mremap" = "xno"], + [AC_MSG_WARN([elf_update needs mremap to support ELF_C_RDWR_MMAP])]) AC_CHECK_HEADERS([error.h]) AC_CHECK_HEADERS([err.h]) diff --git a/libelf/ChangeLog b/libelf/ChangeLog index 985f795d..00d4ac0f 100644 --- a/libelf/ChangeLog +++ b/libelf/ChangeLog @@ -1,3 +1,7 @@ +2022-04-24 Mark Wielaard <m...@klomp.org> + + * elf_update.c (write_file): Check HAVE_MREMAP. + 2022-04-01 Mark Wielaard <m...@klomp.org> * libelfP.h (struct Elf_Data_Chunk): Add an int64_t offset field. diff --git a/libelf/elf_update.c b/libelf/elf_update.c index 9b8867ce..97ca9ca9 100644 --- a/libelf/elf_update.c +++ b/libelf/elf_update.c @@ -106,8 +106,10 @@ write_file (Elf *elf, int64_t size, int change_bo, size_t shnum) if (elf->cmd == ELF_C_RDWR_MMAP && (size_t) size > elf->maximum_size) { +#ifdef HAVE_MREMAP if (mremap (elf->map_address, elf->maximum_size, size, 0) == MAP_FAILED) +#endif { __libelf_seterrno (ELF_E_WRITE_ERROR); return -1; -- 2.30.2
