Received-SPF: pass (google.com: domain of linux-kernel+bounces-1667-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Precedence: bulk
MIME-Version: 1.0
References: <20231215-llvm-decode-stacktrace-v1-1-201cb86f4879@quicinc.com>
In-Reply-To: <20231215-llvm-decode-stacktrace-v1-1-201cb86f4879@quicinc.com>
From: Justin Stitt <justinstitt@google.com>
Date: Fri, 15 Dec 2023 13:19:18 -0800
Message-ID: <CAFhGd8pweTJJU7=iSqXbvSW79fL54B_aLpzwW3nxJ62=UA0b+A@mail.gmail.com>
Subject: Re: [PATCH] scripts/decode_stacktrace.sh: Use LLVM environment variable
To: Elliot Berman <quic_eberman@quicinc.com>
Cc: Nathan Chancellor <nathan@kernel.org>, Nick Desaulniers <ndesaulniers@google.com>, 
	Bill Wendling <morbo@google.com>, Manuel Traut <manut@linutronix.de>, linux-arm-msm@vger.kernel.org, 
	linux-kernel@vger.kernel.org, llvm@lists.linux.dev
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

Hi,

On Fri, Dec 15, 2023 at 10:27=E2=80=AFAM Elliot Berman <quic_eberman@quicin=
c.com> wrote:
>
> When using LLVM as the compiler, decode_stacktrace should also use
> llvm-addr2line. Check if LLVM is set and add the appropriate
> suffix/prefix.
>
> Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
> ---

I tried it out by dropping a random dump_stack() call into the init
phase of the kernel and redirecting the serial console output to a log
file. Using the pre-(this patch) and post-(this patch) script yields
good stack trace results. It seems llvm-addr2line is a drop-in
replacement.

Tested-by: Justin Stitt <justinstitt@google.com>

>  scripts/decode_stacktrace.sh | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/scripts/decode_stacktrace.sh b/scripts/decode_stacktrace.sh
> index 564c5632e1a2..189b00f4e120 100755
> --- a/scripts/decode_stacktrace.sh
> +++ b/scripts/decode_stacktrace.sh
> @@ -16,6 +16,16 @@ elif type c++filt >/dev/null 2>&1 ; then
>         cppfilt_opts=3D-i
>  fi
>
> +if [[ "${LLVM}" =3D=3D "1" ]] ; then
> +       addr2line=3D"llvm-addr2line"
> +elif [[ "${LLVM}" =3D=3D */ ]] ; then
> +       addr2line=3D"${LLVM}llvm-addr2line"
> +elif [[ "${LLVM}" =3D=3D -* ]] ; then
> +       addr2line=3D"llvm-addr2line${LLVM}"
> +else
> +       addr2line=3D"${CROSS_COMPILE}addr2line"
> +fi
> +
>  if [[ $1 =3D=3D "-r" ]] ; then
>         vmlinux=3D""
>         basepath=3D"auto"
> @@ -169,7 +179,7 @@ parse_symbol() {
>         if [[ $aarray_support =3D=3D true && "${cache[$module,$address]+i=
sset}" =3D=3D "isset" ]]; then
>                 local code=3D${cache[$module,$address]}
>         else
> -               local code=3D$(${CROSS_COMPILE}addr2line -i -e "$objfile"=
 "$address" 2>/dev/null)
> +               local code=3D$(${addr2line} -i -e "$objfile" "$address" 2=
>/dev/null)
>                 if [[ $aarray_support =3D=3D true ]]; then
>                         cache[$module,$address]=3D$code
>                 fi
>
> ---
> base-commit: 3f7168591ebf7bbdb91797d02b1afaf00a4289b1
> change-id: 20231214-llvm-decode-stacktrace-09538979006d
>
> Best regards,
> --
> Elliot Berman <quic_eberman@quicinc.com>
>

Thanks
Justin