On Fri, Jul 21, 2023 at 11:01 PM Palmer Dabbelt <palmer@xxxxxxxxxxxx> wrote: > > On Fri, 21 Jul 2023 04:58:20 PDT (-0700), masahiroy@xxxxxxxxxx wrote: > > On Thu, Jul 13, 2023 at 1:28 AM Palmer Dabbelt <palmer@xxxxxxxxxxxx> wrote: > >> > >> On Wed, 12 Jul 2023 08:55:23 PDT (-0700), masahiroy@xxxxxxxxxx wrote: > >> > +To: Luis Chamberlain, the commiter of the breakage > >> > > >> > > >> > > >> > On Wed, Jul 12, 2023 at 10:44 AM Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> wrote: > >> >> > >> >> with "module: Ignore RISC-V mapping symbols too", build error occurs, > >> >> > >> >> scripts/mod/modpost.c: In function ‘is_valid_name’: > >> >> scripts/mod/modpost.c:1055:57: error: ‘EM_RISCV’ undeclared (first use in this function) > >> >> return !is_mapping_symbol(name, elf->hdr->e_machine == EM_RISCV); > >> >> > >> >> Fix it by moving the EM_RISCV to the file head, also some other > >> >> defines in case of similar problem in the future. > >> > > >> > > >> > > >> > BTW, why is the flag 'is_riscv' needed? > >> > > >> > > >> > All symbols starting with '$' look special to me. > >> > > >> > > >> > > >> > Why not like this? > >> > > >> > > >> > if (str[0] == '$') > >> > return true; > >> > > >> > return false; > >> > >> There's a bit of commentary in the v1 > >> <https://lore.kernel.org/all/20230707054007.32591-1-palmer@xxxxxxxxxxxx/>, > >> but essentially it's not necessary. I just wanted to play things safe > >> and avoid changing the mapping symbol detection elsewhere in order to > >> deal with RISC-V. > >> > >> IIRC we decided $ was special in RISC-V because there were some other > >> ports that behaved that way, but it wasn't universal. If folks are OK > >> treating $-prefixed symbols as special everywhere that's fine with me, I > >> just wasn't sure what the right answer was. > >> > >> There's also some similar arch-specific-ness with the labels and such in > >> here. > > > > Hi Palmer, > > > > I am not a toolchain expert, but my gut feeling is > > that the code was safer than needed. > > > > > > I'd like to remove the 'is_riscv' switch rather than > > applying this patch. > > > > Will you send a patch, or do you want me to do so? > > I've pretty much got it already. Do you want it on top of the original > patch, or just squashed in so you can drop it? It is up to Luis Chamberlain. The original patch does not exist in my kbuild tree. (and I was not even not CC'ed, so I had not noticed it before I saw this report) commit c05780ef3c190c2dafbf0be8e65d4f01103ad577 Author: Palmer Dabbelt <palmer@xxxxxxxxxxxx> AuthorDate: Fri Jul 7 09:00:51 2023 -0700 Commit: Luis Chamberlain <mcgrof@xxxxxxxxxx> CommitDate: Mon Jul 10 12:45:23 2023 -0700 module: Ignore RISC-V mapping symbols too RISC-V has an extended form of mapping symbols that we use to encode the ISA when it changes in the middle of an ELF. This trips up modpost as a build failure, I haven't yet verified it yet but I believe the kallsyms difference should result in stacks looking sane again. Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Closes: https://lore.kernel.org/all/9d9e2902-5489-4bf0-d9cb-556c8e5d71c2@xxxxxxxxxxxxx/ Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx> Reviewed-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Tested-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> # build-tested Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx> -- Best Regards Masahiro Yamada
