On Tue, Feb 16, 2021 at 09:56:32AM -0800, 'Nick Desaulniers' via Clang Built Linux wrote: > On Tue, Feb 16, 2021 at 12:55 AM Alexander Lobakin <alobakin@xxxxx> wrote: > > > > LKP triggered lots of LD orphan warnings [0]: > > Thanks for the patch, just some questions. > > With which linker? Was there a particular config from the bot's > report that triggered this? Looks like GNU ld 2.34 (see below). > > > > mipsel-linux-ld: warning: orphan section `.data.$Lubsan_data299' from > > `init/do_mounts_rd.o' being placed in section `.data.$Lubsan_data299' > > mipsel-linux-ld: warning: orphan section `.data.$Lubsan_data183' from > > `init/do_mounts_rd.o' being placed in section `.data.$Lubsan_data183' > > mipsel-linux-ld: warning: orphan section `.data.$Lubsan_type3' from > > `init/do_mounts_rd.o' being placed in section `.data.$Lubsan_type3' > > mipsel-linux-ld: warning: orphan section `.data.$Lubsan_type2' from > > `init/do_mounts_rd.o' being placed in section `.data.$Lubsan_type2' > > mipsel-linux-ld: warning: orphan section `.data.$Lubsan_type0' from > > `init/do_mounts_rd.o' being placed in section `.data.$Lubsan_type0' > > > > [...] > > > > Seems like "unnamed data" isn't the only type of symbols that UBSAN > > instrumentation can emit. > > Catch these into .data with the wildcard as well. > > > > [0] https://lore.kernel.org/linux-mm/202102160741.k57GCNSR-lkp@xxxxxxxxx > > > > Fixes: f41b233de0ae ("vmlinux.lds.h: catch UBSAN's "unnamed data" into data") > > Reported-by: kernel test robot <lkp@xxxxxxxxx> > > Signed-off-by: Alexander Lobakin <alobakin@xxxxx> > > --- > > include/asm-generic/vmlinux.lds.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h > > index cc659e77fcb0..83537e5ee78f 100644 > > --- a/include/asm-generic/vmlinux.lds.h > > +++ b/include/asm-generic/vmlinux.lds.h > > @@ -95,7 +95,7 @@ > > */ > > #ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION > > #define TEXT_MAIN .text .text.[0-9a-zA-Z_]* > > -#define DATA_MAIN .data .data.[0-9a-zA-Z_]* .data..L* .data..compoundliteral* .data.$__unnamed_* > > +#define DATA_MAIN .data .data.[0-9a-zA-Z_]* .data..L* .data..compoundliteral* .data.$__unnamed_* .data.$Lubsan_* > > Are these sections only created when > CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is selected? (Same with > .data.$__unnamed_*) Most likely, as that config is set in the problematic config. My guess is that these are GCC's equivalent of Clang's .data.$__unnamed_... $ crl https://lore.kernel.org/linux-mm/202102160741.k57GCNSR-lkp@xxxxxxxxx/2-a.bin | gzip -d | rg "CONFIG_LD_DEAD_CODE|CONFIG_LD_VERSION" CONFIG_LD_VERSION=234000000 CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y > > #define SDATA_MAIN .sdata .sdata.[0-9a-zA-Z_]* > > #define RODATA_MAIN .rodata .rodata.[0-9a-zA-Z_]* .rodata..L* > > #define BSS_MAIN .bss .bss.[0-9a-zA-Z_]* .bss..compoundliteral* > > -- > > 2.30.1 > > > > > > > -- > Thanks, > ~Nick Desaulniers >
