Hi Jessica, On Tue, 9 Feb 2021 16:16:20 +0100 Jessica Yu 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. > 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? -- Cheers, Stephen Rothwell