2023-07-24 18:32:43

by Will Deacon

Subject: [PATCH 2/2] scripts/faddr2line: Use LLVM addr2line and readelf if LLVM=1

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=1 as an indication to use the llvm- tools.

Cc: Josh Poimboeuf <[email protected]>
Cc: John Stultz <[email protected]>
Signed-off-by: Will Deacon <[email protected]>
---
scripts/faddr2line | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/scripts/faddr2line b/scripts/faddr2line
index 60368a1cdaed..24845267efb2 100755
--- a/scripts/faddr2line
+++ b/scripts/faddr2line
@@ -58,8 +58,14 @@ die() {
exit 1
}

-READELF="${CROSS_COMPILE:-}readelf"
-ADDR2LINE="${CROSS_COMPILE:-}addr2line"
+if [ "${LLVM:-}" == "1" ]; then
+ UTIL_PREFIX=llvm-
+else
+ UTIL_PREFIX=${CROSS_COMPILE:-}
+fi
+
+READELF="${UTIL_PREFIX}readelf"
+ADDR2LINE="${UTIL_PREFIX}addr2line"
AWK="awk"
GREP="grep"

--
2.41.0.487.g6d72f3e995-goog

2023-07-25 00:53:24

by Josh Poimboeuf

Subject: Re: [PATCH 2/2] scripts/faddr2line: Use LLVM addr2line and readelf if LLVM=1

On Mon, Jul 24, 2023 at 06:45:17PM +0100, Will Deacon 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=1 as an indication to use the llvm- tools.
>
> Cc: Josh Poimboeuf <[email protected]>
> Cc: John Stultz <[email protected]>
> Signed-off-by: Will Deacon <[email protected]>

This one looks good to me, I'll go ahead and queue it.

--
Josh

2023-07-25 18:20:26

by Will Deacon

Subject: Re: [PATCH 2/2] scripts/faddr2line: Use LLVM addr2line and readelf if LLVM=1

On Mon, Jul 24, 2023 at 05:07:49PM -0700, Josh Poimboeuf wrote:
> On Mon, Jul 24, 2023 at 06:45:17PM +0100, Will Deacon 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=1 as an indication to use the llvm- tools.
> >
> > Cc: Josh Poimboeuf <[email protected]>
> > Cc: John Stultz <[email protected]>
> > Signed-off-by: Will Deacon <[email protected]>
>
> This one looks good to me, I'll go ahead and queue it.

Thanks, Josh!

Will