[RFC PATCH v2 02/17] objtool: Create disassembly context

Alexandre Chartre posted 17 patches 3 months, 3 weeks ago
[RFC PATCH v2 02/17] objtool: Create disassembly context
Posted by Alexandre Chartre 3 months, 3 weeks ago
Create a structure to store information for disassembling functions.
For now, it is just a wrapper around an objtool file.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
---
 tools/objtool/check.c                   |  6 ++++-
 tools/objtool/disas.c                   | 32 +++++++++++++++++++++++--
 tools/objtool/include/objtool/disas.h   | 14 +++++++++++
 tools/objtool/include/objtool/objtool.h |  2 --
 4 files changed, 49 insertions(+), 5 deletions(-)
 create mode 100644 tools/objtool/include/objtool/disas.h

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index bd1974717fa3..cef3a32a6747 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -11,6 +11,7 @@
 #include <objtool/builtin.h>
 #include <objtool/cfi.h>
 #include <objtool/arch.h>
+#include <objtool/disas.h>
 #include <objtool/check.h>
 #include <objtool/special.h>
 #include <objtool/warn.h>
@@ -4591,6 +4592,7 @@ static void free_insns(struct objtool_file *file)
 
 int check(struct objtool_file *file)
 {
+	struct disas_context *disas_ctx;
 	int ret = 0, warnings = 0;
 
 	arch_initial_func_cfi_state(&initial_func_cfi);
@@ -4720,7 +4722,9 @@ int check(struct objtool_file *file)
 		if (opts.werror && warnings)
 			WARN("%d warning(s) upgraded to errors", warnings);
 		print_args();
-		disas_warned_funcs(file);
+		disas_ctx = disas_context_create(file);
+		disas_warned_funcs(disas_ctx);
+		disas_context_destroy(disas_ctx);
 	}
 
 	return ret;
diff --git a/tools/objtool/disas.c b/tools/objtool/disas.c
index 77de46beb496..67eff2a14832 100644
--- a/tools/objtool/disas.c
+++ b/tools/objtool/disas.c
@@ -4,10 +4,35 @@
  */
 
 #include <objtool/arch.h>
+#include <objtool/disas.h>
 #include <objtool/warn.h>
 
 #include <linux/string.h>
 
+struct disas_context {
+	struct objtool_file *file;
+};
+
+struct disas_context *disas_context_create(struct objtool_file *file)
+{
+	struct disas_context *dctx;
+
+	dctx = malloc(sizeof(*dctx));
+	if (!dctx) {
+		ERROR_GLIBC("failed to allocate disassembly context");
+		return NULL;
+	}
+
+	dctx->file = file;
+
+	return dctx;
+}
+
+void disas_context_destroy(struct disas_context *dctx)
+{
+	free(dctx);
+}
+
 /* 'funcs' is a space-separated list of function names */
 static void disas_funcs(const char *funcs)
 {
@@ -58,12 +83,15 @@ static void disas_funcs(const char *funcs)
 	}
 }
 
-void disas_warned_funcs(struct objtool_file *file)
+void disas_warned_funcs(struct disas_context *dctx)
 {
 	struct symbol *sym;
 	char *funcs = NULL, *tmp;
 
-	for_each_sym(file, sym) {
+	if (!dctx)
+		return;
+
+	for_each_sym(dctx->file, sym) {
 		if (sym->warned) {
 			if (!funcs) {
 				funcs = malloc(strlen(sym->name) + 1);
diff --git a/tools/objtool/include/objtool/disas.h b/tools/objtool/include/objtool/disas.h
new file mode 100644
index 000000000000..5c543b69fc61
--- /dev/null
+++ b/tools/objtool/include/objtool/disas.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2025, Oracle and/or its affiliates.
+ */
+
+#ifndef _DISAS_H
+#define _DISAS_H
+
+struct disas_context;
+struct disas_context *disas_context_create(struct objtool_file *file);
+void disas_context_destroy(struct disas_context *dctx);
+void disas_warned_funcs(struct disas_context *dctx);
+
+#endif /* _DISAS_H */
diff --git a/tools/objtool/include/objtool/objtool.h b/tools/objtool/include/objtool/objtool.h
index 4d3e94b70fd8..c0dc86a78ff6 100644
--- a/tools/objtool/include/objtool/objtool.h
+++ b/tools/objtool/include/objtool/objtool.h
@@ -47,6 +47,4 @@ int check(struct objtool_file *file);
 int orc_dump(const char *objname);
 int orc_create(struct objtool_file *file);
 
-void disas_warned_funcs(struct objtool_file *file);
-
 #endif /* _OBJTOOL_H */
-- 
2.43.5
Re: [RFC PATCH v2 02/17] objtool: Create disassembly context
Posted by Josh Poimboeuf 2 weeks, 1 day ago
On Thu, Jun 19, 2025 at 04:56:44PM +0200, Alexandre Chartre wrote:
> +struct disas_context *disas_context_create(struct objtool_file *file)
> +{
> +	struct disas_context *dctx;
> +
> +	dctx = malloc(sizeof(*dctx));
> +	if (!dctx) {
> +		ERROR_GLIBC("failed to allocate disassembly context");
> +		return NULL;
> +	}

Since this isn't a fatal error, it should probably be WARN_GLIBC() or so.

-- 
Josh