diff mbox series

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

Message ID 20230724174517.15736-3-will@kernel.org
State New
Headers
Series Fix 'faddr2line' for LLVM arm64 builds |

Commit Message

Will Deacon July 24, 2023, 5:45 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=1 as an indication to use the llvm- tools.

Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: John Stultz <jstultz@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
 scripts/faddr2line | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

Comments

Josh Poimboeuf July 25, 2023, 12:07 a.m. UTC | #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 <jpoimboe@kernel.org>
> Cc: John Stultz <jstultz@google.com>
> Signed-off-by: Will Deacon <will@kernel.org>

This one looks good to me, I'll go ahead and queue it.
Will Deacon July 25, 2023, 5:21 p.m. UTC | #2 
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 <jpoimboe@kernel.org>
> > Cc: John Stultz <jstultz@google.com>
> > Signed-off-by: Will Deacon <will@kernel.org>
> 
> This one looks good to me, I'll go ahead and queue it.

Thanks, Josh!

Will
diff mbox series

Patch

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"