On Sat, Jul 29, 2023 at 1:48 PM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote: > > On Fri, Jul 28, 2023 at 8:34 PM Will Deacon <will@xxxxxxxxxx> 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' ^ old GNU binutils missing support for RELR relocation format. https://maskray.me/blog/2021-10-31-relative-relocations-and-relr > > aarch64-linux-gnu-addr2line: DWARF error: invalid or unhandled FORM value: 0x25 ^ old GNU binutils missing support for DWARFv5 I suppose if someone used a new GCC with an old binutils, they could observe the exact same errors. > > 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. > > > Just a note. > The top Makefile accepts not only LLVM=1 > but also LLVM=/usr/lib/llvm-16/bin/. > The latter is useful when you want to use > a particular version or a custom one. Ah, like LLVM_PREFIX/LLVM_SUFFIX a la commit e9c281928c24 ("kbuild: Make $(LLVM) more flexible") Then we could have both UTIL_PREFIX+UTIL_SUFFIX. > > Another idea might be to use a generic '${prefix}' > as this is not hooked to the Makefile, > but I do not have a strong opinion. > > > > > > > > Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> > > Cc: John Stultz <jstultz@xxxxxxxxxx> > > Signed-off-by: Will Deacon <will@xxxxxxxxxx> > > --- > > scripts/faddr2line | 10 ++++++++-- > > 1 file changed, 8 insertions(+), 2 deletions(-) > > > > diff --git a/scripts/faddr2line b/scripts/faddr2line > > index 0e73aca4f908..62a3fa6f6f59 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 > > > > > -- > Best Regards > Masahiro Yamada -- Thanks, ~Nick Desaulniers
