[PATCH 1/3] objtool: Write .orc_lookup section header

[Huaixin Chang <changhuaixin@linux.alibaba.com>]

The purpose of this patch is to set sh_type to SHT_PROGBITS and remove
write bits away from sh_flags. In order to write section header, just
call elf_create_section() upon section orc_lookup with 0 entry written.

Originally, section headers are as follows:

  [23] .orc_unwind_ip    PROGBITS         ffffffff8259f4b8  0179f4b8
       0000000000178bbc  0000000000000000   A       0     0     1
  [24] .rela.orc_unwind_ RELA             0000000000000000  11e57b58
       00000000008d4668  0000000000000018   I      70    23     8
  [25] .orc_unwind       PROGBITS         ffffffff82718074  01918074
       000000000023519a  0000000000000000   A       0     0     1
  [26] .orc_lookup       NOBITS           ffffffff8294d210  01b4d20e
       0000000000030038  0000000000000000  WA       0     0     1
  [27] .vvar             PROGBITS         ffffffff8297e000  01b7e000
       0000000000001000  0000000000000000  WA       0     0     16

Now, they are changed to:

  [23] .orc_unwind_ip    PROGBITS         ffffffff8259f4b8  0179f4b8
       0000000000178bbc  0000000000000000   A       0     0     1
  [24] .rela.orc_unwind_ RELA             0000000000000000  11e57b58
       00000000008d4668  0000000000000018   I      70    23     8
  [25] .orc_unwind       PROGBITS         ffffffff82718074  01918074
       000000000023519a  0000000000000000   A       0     0     1
  [26] .orc_lookup       PROGBITS         ffffffff8294d210  01b4d210
       0000000000030038  0000000000000000   A       0     0     1
  [27] .vvar             PROGBITS         ffffffff8297e000  01b7e000
       0000000000001000  0000000000000000  WA       0     0     16

Signed-off-by: Huaixin Chang <changhuaixin@linux.alibaba.com>
---
 tools/objtool/orc_gen.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c
index 968f55e6dd94..2b2653979ad6 100644
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -189,6 +189,10 @@ int create_orc_sections(struct objtool_file *file)
 	u_sec = elf_create_section(file->elf, ".orc_unwind",
 				   sizeof(struct orc_entry), idx);
 
+	/* make flags of section orc_lookup right */
+	if (!elf_create_section(file->elf, ".orc_lookup", sizeof(int), 0))
+		return -1;
+
 	/* populate sections */
 	idx = 0;
 	for_each_sec(file, sec) {
-- 
2.14.4.44.g2045bb6