[PATCH v2 17/53] objtool: Move mark_rodata() to elf.c

[Josh Poimboeuf]

Move the sec->rodata marking from check.c to elf.c so it's set during
ELF reading rather than during the check pipeline.  This makes the
rodata flag available to all objtool users, including klp-diff which
reads ELF files directly without running check().

Add an is_rodata_sec() helper to elf.h for consistency with
is_text_sec() and is_string_sec().

Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Acked-by: Song Liu <song@xxxxxxxxxx>
Reviewed-by: Miroslav Benes <mbenes@xxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
 tools/objtool/check.c               | 11 +++--------
 tools/objtool/elf.c                 | 13 +++++++++++++
 tools/objtool/include/objtool/elf.h |  5 +++++
 3 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index e3604b1201f9..e7579c4e46dc 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2566,7 +2566,6 @@ static int classify_symbols(struct objtool_file *file)
 static void mark_rodata(struct objtool_file *file)
 {
 	struct section *sec;
-	bool found = false;
 
 	/*
 	 * Search for the following rodata sections, each of which can
@@ -2579,15 +2578,11 @@ static void mark_rodata(struct objtool_file *file)
 	 * .rodata.str1.* sections are ignored; they don't contain jump tables.
 	 */
 	for_each_sec(file->elf, sec) {
-		if ((!strncmp(sec->name, ".rodata", 7) &&
-		     !strstr(sec->name, ".str1.")) ||
-		    !strncmp(sec->name, ".data.rel.ro", 12)) {
-			sec->rodata = true;
-			found = true;
+		if (is_rodata_sec(sec)) {
+			file->rodata = true;
+			return;
 		}
 	}
-
-	file->rodata = found;
 }
 
 static void mark_holes(struct objtool_file *file)
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index dc39132f71c1..87c6e00749c6 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -1138,6 +1138,17 @@ static int read_relocs(struct elf *elf)
 	return 0;
 }
 
+static void mark_rodata(struct elf *elf)
+{
+	struct section *sec;
+
+	for_each_sec(elf, sec) {
+		if ((strstarts(sec->name, ".rodata") && !strstr(sec->name, ".str1.")) ||
+		    strstarts(sec->name, ".data.rel.ro"))
+			sec->rodata = true;
+	}
+}
+
 struct elf *elf_open_read(const char *name, int flags)
 {
 	struct elf *elf;
@@ -1188,6 +1199,8 @@ struct elf *elf_open_read(const char *name, int flags)
 	if (read_sections(elf))
 		goto err;
 
+	mark_rodata(elf);
+
 	if (read_symbols(elf))
 		goto err;
 
diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h
index 00b04029023e..ab5f7017ec34 100644
--- a/tools/objtool/include/objtool/elf.h
+++ b/tools/objtool/include/objtool/elf.h
@@ -317,6 +317,11 @@ static inline bool is_text_sec(struct section *sec)
 	return sec->sh.sh_flags & SHF_EXECINSTR;
 }
 
+static inline bool is_rodata_sec(struct section *sec)
+{
+	return sec->rodata;
+}
+
 static inline bool sec_changed(struct section *sec)
 {
 	return sec->_changed;
-- 
2.53.0