objtool: Add fallback from ELF_C_READ_MMAP to ELF_C_READ

tip:perf/core tip-bot for Arnaldo Carvalho de Melo 1 participant 1 message Jul 14, 2016 objtool

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2016-07-14 07:02 UTC #0 lore raw

Commit-ID:  774bec3fddcccb0b36f319c6d6e8148dc5e8c937
Gitweb:     http://git.kernel.org/tip/774bec3fddcccb0b36f319c6d6e8148dc5e8c937
Author:     Arnaldo Carvalho de Melo <[email protected]>
AuthorDate: Wed, 13 Jul 2016 15:28:51 -0300
Committer:  Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Wed, 13 Jul 2016 15:38:50 -0300

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] open here

Signed-off-by Arnaldo Carvalho de Melo <[email protected]>

---
 tools/objtool/elf.c | 7 +++++++
 1 file changed, 7 insertions(+)

tools/objtool/elf.c +7 -0

index e11f6b6..0d7983a 100644
@@ -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;