objtool: Convert ANNOTATE_RETPOLINE_SAFE to ANNOTATE

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20241128094311.145275669@infradead.org

diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index 96b410b1d4e841eb02f53a4691ee794ceee4ad2c..50340a125953b5248ba32941cd704103042b364d 100644 (file)
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -184,12 +184,7 @@
  * objtool the subsequent indirect jump/call is vouched safe for retpoline
  * builds.
  */
-.macro ANNOTATE_RETPOLINE_SAFE
-.Lhere_\@:
-       .pushsection .discard.retpoline_safe
-       .long .Lhere_\@
-       .popsection
-.endm
+#define ANNOTATE_RETPOLINE_SAFE        ANNOTATE type=ANNOTYPE_RETPOLINE_SAFE
 
 /*
  * (ab)use RETPOLINE_SAFE on RET to annotate away 'bare' RET instructions
@@ -350,11 +345,7 @@
 
 #else /* __ASSEMBLY__ */
 
-#define ANNOTATE_RETPOLINE_SAFE                                        \
-       "999:\n\t"                                              \
-       ".pushsection .discard.retpoline_safe\n\t"              \
-       ".long 999b\n\t"                                        \
-       ".popsection\n\t"
+#define ANNOTATE_RETPOLINE_SAFE ASM_ANNOTATE(ANNOTYPE_RETPOLINE_SAFE)
 
 typedef u8 retpoline_thunk_t[RETPOLINE_THUNK_SIZE];
 extern retpoline_thunk_t __x86_indirect_thunk_array[];

diff --git a/include/linux/objtool_types.h b/include/linux/objtool_types.h
index 4884f8cf84291025853d596b7f28bd5985608c6b..1b348361ad1d7f28c674ba192d530957fe41a135 100644 (file)
--- a/include/linux/objtool_types.h
+++ b/include/linux/objtool_types.h
@@ -58,5 +58,6 @@ struct unwind_hint {
  * Annotate types
  */
 #define ANNOTYPE_NOENDBR               1
+#define ANNOTYPE_RETPOLINE_SAFE                2
 
 #endif /* _LINUX_OBJTOOL_TYPES_H */

diff --git a/tools/include/linux/objtool_types.h b/tools/include/linux/objtool_types.h
index 4884f8cf84291025853d596b7f28bd5985608c6b..1b348361ad1d7f28c674ba192d530957fe41a135 100644 (file)
--- a/tools/include/linux/objtool_types.h
+++ b/tools/include/linux/objtool_types.h
@@ -58,5 +58,6 @@ struct unwind_hint {
  * Annotate types
  */
 #define ANNOTYPE_NOENDBR               1
+#define ANNOTYPE_RETPOLINE_SAFE                2
 
 #endif /* _LINUX_OBJTOOL_TYPES_H */

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index a74ff26860f7243f011e876bf8597242ec2c844a..c5b52309b80dc05e89342a9131fee02df391366c 100644 (file)
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2373,12 +2373,12 @@ static int read_unwind_hints(struct objtool_file *file)
        return 0;
 }
 
-static int read_annotate(struct objtool_file *file, void (*func)(int type, struct instruction *insn))
+static int read_annotate(struct objtool_file *file, int (*func)(int type, struct instruction *insn))
 {
        struct section *sec;
        struct instruction *insn;
        struct reloc *reloc;
-       int type;
+       int type, ret;
 
        sec = find_section_by_name(file->elf, ".discard.annotate_insn");
        if (!sec)
@@ -2406,53 +2406,37 @@ static int read_annotate(struct objtool_file *file, void (*func)(int type, struc
                        return -1;
                }
 
-               func(type, insn);
+               ret = func(type, insn);
+               if (ret < 0)
+                       return ret;
        }
 
        return 0;
 }
 
-static void __annotate_noendbr(int type, struct instruction *insn)
+static int __annotate_noendbr(int type, struct instruction *insn)
 {
        if (type != ANNOTYPE_NOENDBR)
-               return;
+               return 0;
 
        insn->noendbr = 1;
+       return 0;
 }
 
-static int read_retpoline_hints(struct objtool_file *file)
+static int __annotate_retpoline_safe(int type, struct instruction *insn)
 {
-       struct section *rsec;
-       struct instruction *insn;
-       struct reloc *reloc;
-
-       rsec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe");
-       if (!rsec)
+       if (type != ANNOTYPE_RETPOLINE_SAFE)
                return 0;
 
-       for_each_reloc(rsec, reloc) {
-               if (reloc->sym->type != STT_SECTION) {
-                       WARN("unexpected relocation symbol type in %s", rsec->name);
-                       return -1;
-               }
-
-               insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
-               if (!insn) {
-                       WARN("bad .discard.retpoline_safe entry");
-                       return -1;
-               }
-
-               if (insn->type != INSN_JUMP_DYNAMIC &&
-                   insn->type != INSN_CALL_DYNAMIC &&
-                   insn->type != INSN_RETURN &&
-                   insn->type != INSN_NOP) {
-                       WARN_INSN(insn, "retpoline_safe hint not an indirect jump/call/ret/nop");
-                       return -1;
-               }
-
-               insn->retpoline_safe = true;
+       if (insn->type != INSN_JUMP_DYNAMIC &&
+           insn->type != INSN_CALL_DYNAMIC &&
+           insn->type != INSN_RETURN &&
+           insn->type != INSN_NOP) {
+               WARN_INSN(insn, "retpoline_safe hint not an indirect jump/call/ret/nop");
+               return -1;
        }
 
+       insn->retpoline_safe = true;
        return 0;
 }
 
@@ -2742,7 +2726,7 @@ static int decode_sections(struct objtool_file *file)
        if (ret)
                return ret;
 
-       ret = read_retpoline_hints(file);
+       ret = read_annotate(file, __annotate_retpoline_safe);
        if (ret)
                return ret;