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sys/kern/link_elf_obj.c
| Show First 20 Lines • Show All 167 Lines • ▼ Show 20 Lines | #if ELF_TARG_CLASS == ELFCLASS32 | ||||
| "elf32_obj", | "elf32_obj", | ||||
| #else | #else | ||||
| "elf64_obj", | "elf64_obj", | ||||
| #endif | #endif | ||||
| link_elf_methods, sizeof(struct elf_file) | link_elf_methods, sizeof(struct elf_file) | ||||
| }; | }; | ||||
| static int relocate_file(elf_file_t ef); | static int relocate_file(elf_file_t ef); | ||||
| static void elf_obj_cleanup_globals_cache(elf_file_t); | |||||
| static void | static void | ||||
| link_elf_error(const char *filename, const char *s) | link_elf_error(const char *filename, const char *s) | ||||
| { | { | ||||
| if (filename == NULL) | if (filename == NULL) | ||||
| printf("kldload: %s\n", s); | printf("kldload: %s\n", s); | ||||
| else | else | ||||
| printf("kldload: %s: %s\n", filename, s); | printf("kldload: %s: %s\n", filename, s); | ||||
| ▲ Show 20 Lines • Show All 700 Lines • ▼ Show 20 Lines | #endif | ||||
| /* Notify MD code that a module is being loaded. */ | /* Notify MD code that a module is being loaded. */ | ||||
| error = elf_cpu_load_file(lf); | error = elf_cpu_load_file(lf); | ||||
| if (error) | if (error) | ||||
| goto out; | goto out; | ||||
| /* Invoke .ctors */ | /* Invoke .ctors */ | ||||
| link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size); | link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size); | ||||
| elf_obj_cleanup_globals_cache(ef); | |||||
kib: Why do you only clean for the runtime loaded objects, and do not clean for the preloaded… | |||||
| *result = lf; | *result = lf; | ||||
| out: | out: | ||||
| VOP_UNLOCK(nd.ni_vp, 0); | VOP_UNLOCK(nd.ni_vp, 0); | ||||
| vn_close(nd.ni_vp, FREAD, td->td_ucred, td); | vn_close(nd.ni_vp, FREAD, td->td_ucred, td); | ||||
| if (error && lf) | if (error && lf) | ||||
| linker_file_unload(lf, LINKER_UNLOAD_FORCE); | linker_file_unload(lf, LINKER_UNLOAD_FORCE); | ||||
| if (hdr) | if (hdr) | ||||
| ▲ Show 20 Lines • Show All 318 Lines • ▼ Show 20 Lines | if (symp->st_value != 0 && | ||||
| error = callback(file, i, &symval, opaque); | error = callback(file, i, &symval, opaque); | ||||
| if (error) | if (error) | ||||
| return (error); | return (error); | ||||
| } | } | ||||
| } | } | ||||
| return (0); | return (0); | ||||
| } | } | ||||
| static void | |||||
| elf_obj_cleanup_globals_cache(elf_file_t ef) | |||||
| { | |||||
| Elf_Size i; | |||||
| Elf_Sym *sym; | |||||
| for (i = 0; i < ef->ddbsymcnt; i++) { | |||||
| sym = ef->ddbsymtab + i; | |||||
| if (sym->st_shndx == SHN_FBSD_CACHED) { | |||||
| sym->st_shndx = SHN_UNDEF; | |||||
| sym->st_value = 0; | |||||
| } | |||||
| } | |||||
| } | |||||
| /* | /* | ||||
| * Symbol lookup function that can be used when the symbol index is known (ie | * Symbol lookup function that can be used when the symbol index is known (ie | ||||
| * in relocations). It uses the symbol index instead of doing a fully fledged | * in relocations). It uses the symbol index instead of doing a fully fledged | ||||
| * hash table based lookup when such is valid. For example for local symbols. | * hash table based lookup when such is valid. For example for local symbols. | ||||
| * This is not only more efficient, it's also more correct. It's not always | * This is not only more efficient, it's also more correct. It's not always | ||||
| * the case that the symbol can be found through the hash table. | * the case that the symbol can be found through the hash table. | ||||
| */ | */ | ||||
| static Elf_Addr | static Elf_Addr | ||||
| elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps) | elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps) | ||||
| { | { | ||||
| elf_file_t ef = (elf_file_t)lf; | elf_file_t ef = (elf_file_t)lf; | ||||
| const Elf_Sym *sym; | Elf_Sym *sym; | ||||
| const char *symbol; | const char *symbol; | ||||
| Elf_Addr ret; | Elf_Addr ret; | ||||
| /* Don't even try to lookup the symbol if the index is bogus. */ | /* Don't even try to lookup the symbol if the index is bogus. */ | ||||
| if (symidx >= ef->ddbsymcnt) | if (symidx >= ef->ddbsymcnt) | ||||
| return (0); | return (0); | ||||
| sym = ef->ddbsymtab + symidx; | sym = ef->ddbsymtab + symidx; | ||||
| Show All 11 Lines | elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps) | ||||
| case STB_GLOBAL: | case STB_GLOBAL: | ||||
| /* Relative to Data or Function name */ | /* Relative to Data or Function name */ | ||||
| symbol = ef->ddbstrtab + sym->st_name; | symbol = ef->ddbstrtab + sym->st_name; | ||||
| /* Force a lookup failure if the symbol name is bogus. */ | /* Force a lookup failure if the symbol name is bogus. */ | ||||
| if (*symbol == 0) | if (*symbol == 0) | ||||
| return (0); | return (0); | ||||
| ret = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps)); | ret = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps)); | ||||
| return ret; | /* Cache global lookups */ | ||||
| if (ret != 0) { | |||||
| sym->st_shndx = SHN_FBSD_CACHED; | |||||
| sym->st_value = ret; | |||||
| } | |||||
| return (ret); | |||||
| case STB_WEAK: | case STB_WEAK: | ||||
| printf("link_elf_obj: Weak symbols not supported\n"); | printf("link_elf_obj: Weak symbols not supported\n"); | ||||
| return (0); | return (0); | ||||
| default: | default: | ||||
| return (0); | return (0); | ||||
| } | } | ||||
| ▲ Show 20 Lines • Show All 132 Lines • Show Last 20 Lines | |||||
Why do you only clean for the runtime loaded objects, and do not clean for the preloaded objects ?
IMO, the cleanup must be done much closer to the relocator, probably in relocate_file().
It would be nice to assert that kld_sx is exclusively owned while SHN_FBSD_CACHED hack is in the symbol table, but this might be not easy to implement.