[PATCH 02/11] objtool: Convert ANNOTATE_NOENDBR to ANNOTATE

Peter Zijlstra
2023-12-04T09:40:05Z

include/linux/objtool.h | 17 ++++-------------
include/linux/objtool_types.h | 5 +++++
tools/include/linux/objtool_types.h | 5 +++++
tools/objtool/check.c | 32 +++++---------------------------
4 files changed, 19 insertions(+), 40 deletions(-)

--- a/include/linux/objtool.h
+++ b/include/linux/objtool.h
@@ -45,12 +45,6 @@
#define STACK_FRAME_NON_STANDARD_FP(func)
#endif

-#define ANNOTATE_NOENDBR \
- "986: \n\t" \
- ".pushsection .discard.noendbr\n\t" \
- ".long 986b\n\t" \
- ".popsection\n\t"
-
#define ASM_REACHABLE \
"998:\n\t" \
".pushsection .discard.reachable\n\t" \
@@ -64,6 +58,8 @@
".long " __stringify(x) "\n\t" \
".popsection\n\t"

+#define ANNOTATE_NOENDBR ASM_ANNOTATE(ANNOTYPE_NOENDBR)
+
#else /* __ASSEMBLY__ */

/*
@@ -122,13 +118,6 @@
#endif
.endm

-.macro ANNOTATE_NOENDBR
-.Lhere_\@:
- .pushsection .discard.noendbr
- .long .Lhere_\@
- .popsection
-.endm
-
/*
* Use objtool to validate the entry requirement that all code paths do
* VALIDATE_UNRET_END before RET.
@@ -161,6 +150,8 @@
.popsection
.endm

+#define ANNOTATE_NOENDBR ANNOTATE type=ANNOTYPE_NOENDBR
+
#endif /* __ASSEMBLY__ */

#else /* !CONFIG_OBJTOOL */
--- a/include/linux/objtool_types.h
+++ b/include/linux/objtool_types.h
@@ -54,4 +54,9 @@ struct unwind_hint {
#define UNWIND_HINT_TYPE_SAVE 6
#define UNWIND_HINT_TYPE_RESTORE 7

+/*
+ * Annotate types
+ */
+#define ANNOTYPE_NOENDBR 1
+
#endif /* _LINUX_OBJTOOL_TYPES_H */
--- a/tools/include/linux/objtool_types.h
+++ b/tools/include/linux/objtool_types.h
@@ -54,4 +54,9 @@ struct unwind_hint {
#define UNWIND_HINT_TYPE_SAVE 6
#define UNWIND_HINT_TYPE_RESTORE 7

+/*
+ * Annotate types
+ */
+#define ANNOTYPE_NOENDBR 1
+
#endif /* _LINUX_OBJTOOL_TYPES_H */
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2339,32 +2339,12 @@ static int read_annotate(struct objtool_
return 0;
}

-static void __annotate_nop(int type, struct instruction *insn)
+static void __annotate_noendbr(int type, struct instruction *insn)
{
-}
-
-static int read_noendbr_hints(struct objtool_file *file)
-{
- struct instruction *insn;
- struct section *rsec;
- struct reloc *reloc;
-
- rsec = find_section_by_name(file->elf, ".rela.discard.noendbr");
- if (!rsec)
- return 0;
+ if (type != ANNOTYPE_NOENDBR)
+ return;

- for_each_reloc(rsec, reloc) {
- insn = find_insn(file, reloc->sym->sec,
- reloc->sym->offset + reloc_addend(reloc));
- if (!insn) {
- WARN("bad .discard.noendbr entry");
- return -1;
- }
-
- insn->noendbr = 1;
- }
-
- return 0;
+ insn->noendbr = 1;
}

static int read_retpoline_hints(struct objtool_file *file)
@@ -2637,12 +2617,10 @@ static int decode_sections(struct objtoo
if (ret)
return ret;

- ret = read_annotate(file, __annotate_nop);
-
/*
* Must be before read_unwind_hints() since that needs insn->noendbr.
*/
- ret = read_noendbr_hints(file);
+ ret = read_annotate(file, __annotate_noendbr);
if (ret)
return ret;