On Wed, Feb 10, 2021 at 5:06 PM Jessica Yu <jeyu@xxxxxxxxxx> wrote: > > +++ Stephen Rothwell [10/02/21 08:50 +1100]: > >Hi Jessica, > > > >On Tue, 9 Feb 2021 16:16:20 +0100 Jessica Yu <jeyu@xxxxxxxxxx> wrote: > >> > >> Hmm, these errors don't look like it's related to that particular commit. I was > > > >I found this commit by bisection and then tested by reverting it. > > > >Before this commit, CONFIG_TRIM_UNUSED_KSYMS would not be set in the > >allyesconfig build because CONFIG_UNUSED_SYMBOLS was set. After this > >commit, CONFIG_TRIM_UNUSED_KSYMS will be set in the allyesconfig build. > > Ah, that makes sense then. I would get the error on powerpc whenever > CONFIG_TRIM_UNUSED_KSYMS was enabled. > > >> able to reproduce these weird autoksym errors even without any modules-next > >> patches applied, and on a clean v5.11-rc7 tree. To reproduce it, > >> CONFIG_TRIM_UNUSED_KSYMS needs to be enabled. I guess that's why we run into > >> these errors with allyesconfig. I used a gcc-7 ppc64le cross compiler and got > >> the same compiler warnings. It seems to not compile on powerpc properly because > >> it looks like some symbols have an extra dot "." prefix, for example in > >> kthread.o: > >> > >> 168: 0000000000000318 24 NOTYPE GLOBAL DEFAULT 6 kthread_create_worker > >> 169: 0000000000001d90 104 FUNC GLOBAL DEFAULT 1 .kthread_create_worker > >> 170: 0000000000000330 24 NOTYPE GLOBAL DEFAULT 6 kthread_create_worker_on_cpu > >> 171: 0000000000001e00 88 FUNC GLOBAL DEFAULT 1 .kthread_create_worker_on_cpu > >> 172: 0000000000000348 24 NOTYPE GLOBAL DEFAULT 6 kthread_queue_work > >> 173: 0000000000001e60 228 FUNC GLOBAL DEFAULT 1 .kthread_queue_work > >> > >> So I suppose this dot prefix is specific to powerpc. From the ppc64 elf abi docs: > >> > >> Symbol names with a dot (.) prefix are reserved for holding entry point > >> addresses. The value of a symbol named ".FN", if it exists, is the entry point > >> of the function "FN". > >> > >> I guess the presence of the extra dot symbols is confusing > >> scripts/gen_autoksyms.sh, so we get the dot symbols in autoksyms.h, which the > >> preprocessor doesn't like. I am wondering how this was never caught until now > >> and also now curious if this feature was ever functional on powerpc.. > > > >Which feature? > > Sorry, by "feature" I meant CONFIG_TRIM_UNUSED_KSYMS. This config > option was introduced around v4.7. If simply enabling it produces > these compilation errors I was wondering if it ever built properly on > powerpc. > > Thanks, > > Jessica Thanks for the report. I think the following will fix the issue, but modpost needs fixing too. diff --git a/scripts/gen_autoksyms.sh b/scripts/gen_autoksyms.sh index 16c0b2ddaa4c..996a7109167b 100755 --- a/scripts/gen_autoksyms.sh +++ b/scripts/gen_autoksyms.sh @@ -44,7 +44,7 @@ sed 's/ko$/mod/' $modlist | xargs -n1 sed -n -e '2{s/ /\n/g;/^$/!p;}' -- | cat - "$ksym_wl" | sort -u | -sed -e 's/\(.*\)/#define __KSYM_\1 1/' >> "$output_file" +sed -e 's/^\.\{,1\}\(.*\)/#define __KSYM_\1 1/' >> "$output_file" # Special case for modversions (see modpost.c) if [ -n "$CONFIG_MODVERSIONS" ]; then m I will post two patches with some commit log after some testing. (one for gen_autoksyms.sh and the other for modpost). -- Best Regards Masahiro Yamada