diff mbox series

[RFC,14/17] objtool: arm64: Cache section with switch table information

Message ID 20210120173800.1660730-15-jthierry@redhat.com (mailing list archive)
State New, archived
Headers show
Series objtool: add base support for arm64 | expand

Commit Message

Julien Thierry Jan. 20, 2021, 5:37 p.m. UTC 
Section ".discard.switch_table_info", created by the gcc plugin will
be looked up for every dynamic jump in the object file while the section
might not even exist.

Cache the result of the first lookup.

Signed-off-by: Julien Thierry <jthierry@redhat.com>
---
 tools/objtool/arch/arm64/special.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/tools/objtool/arch/arm64/special.c b/tools/objtool/arch/arm64/special.c
index 396b9c5feebd..c9c3e0bfd581 100644
--- a/tools/objtool/arch/arm64/special.c
+++ b/tools/objtool/arch/arm64/special.c
@@ -33,6 +33,19 @@  bool arch_support_alt_relocation(struct special_alt *special_alt,
 	return false;
 }
 
+static struct section *get_switch_table_info_section(struct objtool_file *file)
+{
+	static bool first = true;
+	static struct section *info_section = NULL;
+
+	if (first) {
+		first = false;
+		info_section = find_section_by_name(file->elf,
+						    ".discard.switch_table_info");
+	}
+
+	return info_section;
+}
 
 /*
  * Aarch64 jump tables are just arrays of offsets (of varying size/signess)
@@ -64,8 +77,7 @@  struct reloc *arch_find_switch_table(struct objtool_file *file,
 	void *sti_sec_start;
 	struct reloc *text_reloc;
 
-	table_info_sec = find_section_by_name(file->elf,
-					      ".discard.switch_table_info");
+	table_info_sec = get_switch_table_info_section(file);
 	if (!table_info_sec)
 		goto try_c_jmptbl;