objtool: Add fallback from ELF_C_READ_MMAP to ELF_C_READ

Not all libelf implementations have this "Please, ELF_C_READ, but use
mmap if possible" elf_begin() cmd, so provide a fallback to plain old
ELF_C_READ.

Case in point: Alpine Linux 3.4.

Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index e11f6b69cce67e05b16c31767fbf36a8f68f0af4..0d7983ac63ef9e300110d9a6ec6771a75378784e 100644 (file)
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -30,6 +30,13 @@
 #include "elf.h"
 #include "warn.h"
 
+/*
+ * Fallback for systems without this "read, mmaping if possible" cmd.
+ */
+#ifndef ELF_C_READ_MMAP
+#define ELF_C_READ_MMAP ELF_C_READ
+#endif
+
 struct section *find_section_by_name(struct elf *elf, const char *name)
 {
        struct section *sec;