objtool: Add WARN_INSN()

It's easier to use and also gives easy access to the instruction's
containing function, which is useful for printing that function's
symbol.  It will also be useful in the future for rate-limiting and
disassembly of warned functions.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/2eaa3155c90fba683d8723599f279c46025b75f3.1681325924.git.jpoimboe@kernel.org

tools/objtool/include/objtool/warn.h

@@ -53,6 +53,11 @@ static inline char *offstr(struct section *sec, unsigned long offset)
 	free(_str);					\
 })
 
+#define WARN_INSN(insn, format, ...)					\
+({									\
+	WARN_FUNC(format, insn->sec, insn->offset,  ##__VA_ARGS__);	\
+})
+
 #define BT_FUNC(format, insn, ...)			\
 ({							\
 	struct instruction *_insn = (insn);		\

tools/objtool/orc_gen.c

@@ -47,8 +47,7 @@ static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi,
 		orc->type = ORC_TYPE_REGS_PARTIAL;
 		break;
 	default:
-		WARN_FUNC("unknown unwind hint type %d",
-			  insn->sec, insn->offset, cfi->type);
+		WARN_INSN(insn, "unknown unwind hint type %d", cfi->type);
 		return -1;
 	}
 
@@ -80,8 +79,7 @@ static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi,
 		orc->sp_reg = ORC_REG_DX;
 		break;
 	default:
-		WARN_FUNC("unknown CFA base reg %d",
-			  insn->sec, insn->offset, cfi->cfa.base);
+		WARN_INSN(insn, "unknown CFA base reg %d", cfi->cfa.base);
 		return -1;
 	}
 
@@ -96,8 +94,7 @@ static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi,
 		orc->bp_reg = ORC_REG_BP;
 		break;
 	default:
-		WARN_FUNC("unknown BP base reg %d",
-			  insn->sec, insn->offset, bp->base);
+		WARN_INSN(insn, "unknown BP base reg %d", bp->base);
 		return -1;
 	}