[PATCH v2] scripts: Create objdump-func helper script

From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
	Miroslav Benes <mbenes@suse.cz>
Subject: [PATCH v2] scripts: Create objdump-func helper script
Date: Tue, 19 Apr 2022 09:12:23 -0700	[thread overview]
Message-ID: <fe61d8835ba60ef20920d2d0e6493748c80e4d7e.1650384661.git.jpoimboe@redhat.com> (raw)

Add a simple script which disassembles a single function from an object
file.  Comes in handy for objtool warnings and kernel stack traces.

Originally-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
v2:
- require gawk

 scripts/objdump-func | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100755 scripts/objdump-func

diff --git a/scripts/objdump-func b/scripts/objdump-func
new file mode 100755
index 000000000000..67229acfe3a6
--- /dev/null
+++ b/scripts/objdump-func
@@ -0,0 +1,18 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Disassemble a single function.
+#
+# usage: objdump-func <file> <func>
+
+set -o errexit
+set -o nounset
+
+OBJDUMP="${CROSS_COMPILE:-}objdump"
+
+command -v gawk >/dev/null 2>&1 || die "gawk isn't installed"
+
+OBJ=$1; shift
+FUNC=$1; shift
+
+${OBJDUMP} -wdr $@ $OBJ | gawk "/^\$/ { P=0; } /$FUNC[^>]*>:\$/ { P=1; O=strtonum(\"0x\" \$1); } { if (P) { o=strtonum(\"0x\" \$1); printf(\"%04x \", o-O); print \$0; } }"
-- 
2.34.1

