perf jit: genelf makes assumptions about endian

Commit 9b07e27f88b9 ("perf inject: Add jitdump mmap injection support")
incorrectly assumed that PowerPC is big endian only.

Simplify things by consolidating the define of GEN_ELF_ENDIAN and checking
for __BYTE_ORDER == __BIG_ENDIAN.

The PowerPC checks were also incorrect, they do not match what gcc
emits. We should first look for __powerpc64__, then __powerpc__.

Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Carl Love <cel@us.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Fixes: 9b07e27f88b9 ("perf inject: Add jitdump mmap injection support")
Link: http://lkml.kernel.org/r/20160329175944.33a211cc@kryten
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/genelf.h

@@ -9,36 +9,32 @@ int jit_add_debug_info(Elf *e, uint64_t code_addr, void *debug, int nr_debug_ent
 
 #if   defined(__arm__)
 #define GEN_ELF_ARCH	EM_ARM
-#define GEN_ELF_ENDIAN	ELFDATA2LSB
 #define GEN_ELF_CLASS	ELFCLASS32
 #elif defined(__aarch64__)
 #define GEN_ELF_ARCH	EM_AARCH64
-#define GEN_ELF_ENDIAN	ELFDATA2LSB
 #define GEN_ELF_CLASS	ELFCLASS64
 #elif defined(__x86_64__)
 #define GEN_ELF_ARCH	EM_X86_64
-#define GEN_ELF_ENDIAN	ELFDATA2LSB
 #define GEN_ELF_CLASS	ELFCLASS64
 #elif defined(__i386__)
 #define GEN_ELF_ARCH	EM_386
-#define GEN_ELF_ENDIAN	ELFDATA2LSB
 #define GEN_ELF_CLASS	ELFCLASS32
-#elif defined(__ppcle__)
-#define GEN_ELF_ARCH	EM_PPC
-#define GEN_ELF_ENDIAN	ELFDATA2LSB
-#define GEN_ELF_CLASS	ELFCLASS64
-#elif defined(__powerpc__)
-#define GEN_ELF_ARCH	EM_PPC64
-#define GEN_ELF_ENDIAN	ELFDATA2MSB
-#define GEN_ELF_CLASS	ELFCLASS64
-#elif defined(__powerpcle__)
+#elif defined(__powerpc64__)
 #define GEN_ELF_ARCH	EM_PPC64
-#define GEN_ELF_ENDIAN	ELFDATA2LSB
 #define GEN_ELF_CLASS	ELFCLASS64
+#elif defined(__powerpc__)
+#define GEN_ELF_ARCH	EM_PPC
+#define GEN_ELF_CLASS	ELFCLASS32
 #else
 #error "unsupported architecture"
 #endif
 
+#if __BYTE_ORDER == __BIG_ENDIAN
+#define GEN_ELF_ENDIAN	ELFDATA2MSB
+#else
+#define GEN_ELF_ENDIAN	ELFDATA2LSB
+#endif
+
 #if GEN_ELF_CLASS == ELFCLASS64
 #define elf_newehdr	elf64_newehdr
 #define elf_getshdr	elf64_getshdr