G'day, All. First post so please be gentle ;-). Are the barracudas here?
Summary: Module link-elf will link against static symbols and will fail if the kernel is not compiled with DDB or the required MODULE_DEPEND has been stripped of local symbols, see nm -g miibus.ko. I propose that we add a sysctl & associated boot arg that only allows kmod loading against externally visible symbols. Then in 11 we can enable this flag by default. In Detail: Due to another bug in sys/conf/kmod.mk, (http://www.freebsd.org/cgi/query-pr.cgi?pr=177008, contains a patch) the miibus.ko exports no symbols. I.e. symbols are 'static'. sys/kern/link-elf.c:link_elf_lookup_symbol() is the culprit. After determining that an external symbol can't be found, it does the following. /* If we have not found it, look at the full table (if loaded) */ if (ef->symtab == ef->ddbsymtab) return (ENOENT); /* Exhaustive search */ for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) { strp = ef->ddbstrtab + symp->st_name; if (strcmp(name, strp) == 0) { if (symp->st_shndx != SHN_UNDEF || (symp->st_value != 0 && ELF_ST_TYPE(symp->st_info) == STT_FUNC)) { *sym = (c_linker_sym_t) symp; return (0); } return (ENOENT); } } This code walks the ddbsymtab looking for any symbol, including locals. Any kernel that is not built with DDB or any MODULE_DEPEND dependency .ko that is stripped will break module loading. Godfrey van der Linden _______________________________________________ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
