Re: [PATCH v2 13/25] scripts: Create objdump-func helper script

[Peter Zijlstra <peterz@infradead.org>]

On Mon, Apr 18, 2022 at 09:50:32AM -0700, Josh Poimboeuf wrote:
> 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>
> ---
>  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..140646c456fc
> --- /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 awk >/dev/null 2>&1 || die "awk isn't installed"
> +
> +OBJ=$1; shift
> +FUNC=$1; shift
> +
> +${OBJDUMP} -wdr $@ $OBJ | awk "/^\$/ { P=0; } /$FUNC[^>]*>:\$/ { P=1; O=strtonum(\"0x\" \$1); } { if (P) { o=strtonum(\"0x\" \$1); printf(\"%04x \", o-O); print \$0; } }"
> -- 
> 2.34.1
> 

This might rely on awk being gawk, I'm never very careful about those
things.