diff mbox series

[v4,2/3] scripts/faddr2line: Use LLVM addr2line and readelf if LLVM=1

Message ID 20230914131225.13415-3-will@kernel.org (mailing list archive)
State New, archived
Headers show
Series Fix 'faddr2line' for LLVM arm64 builds | expand

Commit Message

Will Deacon Sept. 14, 2023, 1:12 p.m. UTC
GNU utilities cannot necessarily parse objects built by LLVM, which can
result in confusing errors when using 'faddr2line':

$ CROSS_COMPILE=aarch64-linux-gnu- ./scripts/faddr2line vmlinux do_one_initcall+0xf4/0x260
aarch64-linux-gnu-addr2line: vmlinux: unknown type [0x13] section `.relr.dyn'
aarch64-linux-gnu-addr2line: DWARF error: invalid or unhandled FORM value: 0x25
do_one_initcall+0xf4/0x260:
aarch64-linux-gnu-addr2line: vmlinux: unknown type [0x13] section `.relr.dyn'
aarch64-linux-gnu-addr2line: DWARF error: invalid or unhandled FORM value: 0x25
$x.73 at main.c:?

Although this can be worked around by setting CROSS_COMPILE to "llvm=-",
it's cleaner to follow the same syntax as the top-level Makefile and
accept LLVM= as an indication to use the llvm- tools, optionally
specifying their location or specific version number.

Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: John Stultz <jstultz@google.com>
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
---
 scripts/faddr2line | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

Comments

Nick Desaulniers Sept. 14, 2023, 3:55 p.m. UTC | #1
On Thu, Sep 14, 2023 at 6:12 AM Will Deacon <will@kernel.org> wrote:
>
> GNU utilities cannot necessarily parse objects built by LLVM, which can
> result in confusing errors when using 'faddr2line':
>
> $ CROSS_COMPILE=aarch64-linux-gnu- ./scripts/faddr2line vmlinux do_one_initcall+0xf4/0x260
> aarch64-linux-gnu-addr2line: vmlinux: unknown type [0x13] section `.relr.dyn'
> aarch64-linux-gnu-addr2line: DWARF error: invalid or unhandled FORM value: 0x25
> do_one_initcall+0xf4/0x260:
> aarch64-linux-gnu-addr2line: vmlinux: unknown type [0x13] section `.relr.dyn'
> aarch64-linux-gnu-addr2line: DWARF error: invalid or unhandled FORM value: 0x25
> $x.73 at main.c:?
>
> Although this can be worked around by setting CROSS_COMPILE to "llvm=-",
> it's cleaner to follow the same syntax as the top-level Makefile and
> accept LLVM= as an indication to use the llvm- tools, optionally
> specifying their location or specific version number.
>
> Cc: Josh Poimboeuf <jpoimboe@kernel.org>
> Cc: John Stultz <jstultz@google.com>
> Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
> Signed-off-by: Will Deacon <will@kernel.org>

Thanks for the patch series!
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

> ---
>  scripts/faddr2line | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/scripts/faddr2line b/scripts/faddr2line
> index a35a420d0f26..6b8206802157 100755
> --- a/scripts/faddr2line
> +++ b/scripts/faddr2line
> @@ -58,8 +58,21 @@ die() {
>         exit 1
>  }
>
> -READELF="${CROSS_COMPILE:-}readelf"
> -ADDR2LINE="${CROSS_COMPILE:-}addr2line"
> +UTIL_SUFFIX=""
> +if [[ "${LLVM:-}" == "" ]]; then
> +       UTIL_PREFIX=${CROSS_COMPILE:-}
> +else
> +       UTIL_PREFIX=llvm-
> +
> +       if [[ "${LLVM}" == *"/" ]]; then
> +               UTIL_PREFIX=${LLVM}${UTIL_PREFIX}
> +       elif [[ "${LLVM}" == "-"* ]]; then
> +               UTIL_SUFFIX=${LLVM}
> +       fi
> +fi
> +
> +READELF="${UTIL_PREFIX}readelf${UTIL_SUFFIX}"
> +ADDR2LINE="${UTIL_PREFIX}addr2line${UTIL_SUFFIX}"
>  AWK="awk"
>  GREP="grep"
>
> --
> 2.42.0.283.g2d96d420d3-goog
>
diff mbox series

Patch

diff --git a/scripts/faddr2line b/scripts/faddr2line
index a35a420d0f26..6b8206802157 100755
--- a/scripts/faddr2line
+++ b/scripts/faddr2line
@@ -58,8 +58,21 @@  die() {
 	exit 1
 }
 
-READELF="${CROSS_COMPILE:-}readelf"
-ADDR2LINE="${CROSS_COMPILE:-}addr2line"
+UTIL_SUFFIX=""
+if [[ "${LLVM:-}" == "" ]]; then
+	UTIL_PREFIX=${CROSS_COMPILE:-}
+else
+	UTIL_PREFIX=llvm-
+
+	if [[ "${LLVM}" == *"/" ]]; then
+		UTIL_PREFIX=${LLVM}${UTIL_PREFIX}
+	elif [[ "${LLVM}" == "-"* ]]; then
+		UTIL_SUFFIX=${LLVM}
+	fi
+fi
+
+READELF="${UTIL_PREFIX}readelf${UTIL_SUFFIX}"
+ADDR2LINE="${UTIL_PREFIX}addr2line${UTIL_SUFFIX}"
 AWK="awk"
 GREP="grep"