From 22e268ebecc549f1b1907f114cb44d6044bdee3c Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 5 Aug 2010 12:59:05 -0600 Subject: [PATCH] module: refactor load_module part 5 1) Extract out the relocation loop into apply_relocations 2) Extract license and version checks into check_module_license_and_versions 3) Extract icache flushing into flush_module_icache 4) Move __obsparm warning into find_module_sections 5) Move license setting into check_modinfo. Signed-off-by: Rusty Russell --- kernel/module.c | 182 ++++++++++++++++++++++++++++-------------------- 1 file changed, 106 insertions(+), 76 deletions(-) diff --git a/kernel/module.c b/kernel/module.c index 241bc41dd6be..b536db804ca0 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1698,6 +1698,39 @@ static int simplify_symbols(Elf_Shdr *sechdrs, return ret; } +static int apply_relocations(struct module *mod, + Elf_Ehdr *hdr, + Elf_Shdr *sechdrs, + unsigned int symindex, + unsigned int strindex) +{ + unsigned int i; + int err = 0; + + /* Now do relocations. */ + for (i = 1; i < hdr->e_shnum; i++) { + const char *strtab = (char *)sechdrs[strindex].sh_addr; + unsigned int info = sechdrs[i].sh_info; + + /* Not a valid relocation section? */ + if (info >= hdr->e_shnum) + continue; + + /* Don't bother with non-allocated sections */ + if (!(sechdrs[info].sh_flags & SHF_ALLOC)) + continue; + + if (sechdrs[i].sh_type == SHT_REL) + err = apply_relocate(sechdrs, strtab, symindex, i, mod); + else if (sechdrs[i].sh_type == SHT_RELA) + err = apply_relocate_add(sechdrs, strtab, symindex, i, + mod); + if (err < 0) + break; + } + return err; +} + /* Additional bytes needed by arch in front of individual sections */ unsigned int __weak arch_mod_section_prepend(struct module *mod, unsigned int section) @@ -2179,6 +2212,10 @@ static int check_modinfo(struct module *mod, " the quality is unknown, you have been warned.\n", mod->name); } + + /* Set up license info based on the info section */ + set_license(mod, get_modinfo(sechdrs, infoindex, "license")); + return 0; } @@ -2245,6 +2282,10 @@ static void find_module_sections(struct module *mod, Elf_Ehdr *hdr, sizeof(*mod->ftrace_callsites), &mod->num_ftrace_callsites); #endif + + if (section_addr(hdr, sechdrs, secstrings, "__obsparm")) + printk(KERN_WARNING "%s: Ignoring obsolete parameters\n", + mod->name); } static struct module *move_module(struct module *mod, @@ -2311,6 +2352,60 @@ static struct module *move_module(struct module *mod, return mod; } +static int check_module_license_and_versions(struct module *mod, + Elf_Shdr *sechdrs) +{ + /* + * ndiswrapper is under GPL by itself, but loads proprietary modules. + * Don't use add_taint_module(), as it would prevent ndiswrapper from + * using GPL-only symbols it needs. + */ + if (strcmp(mod->name, "ndiswrapper") == 0) + add_taint(TAINT_PROPRIETARY_MODULE); + + /* driverloader was caught wrongly pretending to be under GPL */ + if (strcmp(mod->name, "driverloader") == 0) + add_taint_module(mod, TAINT_PROPRIETARY_MODULE); + +#ifdef CONFIG_MODVERSIONS + if ((mod->num_syms && !mod->crcs) + || (mod->num_gpl_syms && !mod->gpl_crcs) + || (mod->num_gpl_future_syms && !mod->gpl_future_crcs) +#ifdef CONFIG_UNUSED_SYMBOLS + || (mod->num_unused_syms && !mod->unused_crcs) + || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs) +#endif + ) { + return try_to_force_load(mod, + "no versions for exported symbols"); + } +#endif + return 0; +} + +static void flush_module_icache(const struct module *mod) +{ + mm_segment_t old_fs; + + /* flush the icache in correct context */ + old_fs = get_fs(); + set_fs(KERNEL_DS); + + /* + * Flush the instruction cache, since we've played with text. + * Do it before processing of module parameters, so the module + * can provide parameter accessor functions of its own. + */ + if (mod->module_init) + flush_icache_range((unsigned long)mod->module_init, + (unsigned long)mod->module_init + + mod->init_size); + flush_icache_range((unsigned long)mod->module_core, + (unsigned long)mod->module_core + mod->core_size); + + set_fs(old_fs); +} + /* Allocate and load the module: note that size of section 0 is always zero, and we rely on this for optional sections. */ static noinline struct module *load_module(void __user *umod, @@ -2331,8 +2426,6 @@ static noinline struct module *load_module(void __user *umod, struct _ddebug *debug = NULL; unsigned int num_debug = 0; - mm_segment_t old_fs; - DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n", umod, len, uargs); @@ -2453,20 +2546,13 @@ static noinline struct module *load_module(void __user *umod, if (err) goto free_init; - /* Set up license info based on the info section */ - set_license(mod, get_modinfo(sechdrs, infoindex, "license")); - - /* - * ndiswrapper is under GPL by itself, but loads proprietary modules. - * Don't use add_taint_module(), as it would prevent ndiswrapper from - * using GPL-only symbols it needs. - */ - if (strcmp(mod->name, "ndiswrapper") == 0) - add_taint(TAINT_PROPRIETARY_MODULE); + /* Now we've got everything in the final locations, we can + * find optional sections. */ + find_module_sections(mod, hdr, sechdrs, secstrings); - /* driverloader was caught wrongly pretending to be under GPL */ - if (strcmp(mod->name, "driverloader") == 0) - add_taint_module(mod, TAINT_PROPRIETARY_MODULE); + err = check_module_license_and_versions(mod, sechdrs); + if (err) + goto free_unload; /* Set up MODINFO_ATTR fields */ setup_modinfo(mod, sechdrs, infoindex); @@ -2477,47 +2563,9 @@ static noinline struct module *load_module(void __user *umod, if (err < 0) goto cleanup; - /* Now we've got everything in the final locations, we can - * find optional sections. */ - find_module_sections(mod, hdr, sechdrs, secstrings); - -#ifdef CONFIG_MODVERSIONS - if ((mod->num_syms && !mod->crcs) - || (mod->num_gpl_syms && !mod->gpl_crcs) - || (mod->num_gpl_future_syms && !mod->gpl_future_crcs) -#ifdef CONFIG_UNUSED_SYMBOLS - || (mod->num_unused_syms && !mod->unused_crcs) - || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs) -#endif - ) { - err = try_to_force_load(mod, - "no versions for exported symbols"); - if (err) - goto cleanup; - } -#endif - - /* Now do relocations. */ - for (i = 1; i < hdr->e_shnum; i++) { - const char *strtab = (char *)sechdrs[strindex].sh_addr; - unsigned int info = sechdrs[i].sh_info; - - /* Not a valid relocation section? */ - if (info >= hdr->e_shnum) - continue; - - /* Don't bother with non-allocated sections */ - if (!(sechdrs[info].sh_flags & SHF_ALLOC)) - continue; - - if (sechdrs[i].sh_type == SHT_REL) - err = apply_relocate(sechdrs, strtab, symindex, i,mod); - else if (sechdrs[i].sh_type == SHT_RELA) - err = apply_relocate_add(sechdrs, strtab, symindex, i, - mod); - if (err < 0) - goto cleanup; - } + err = apply_relocations(mod, hdr, sechdrs, symindex, strindex); + if (err < 0) + goto cleanup; /* Set up and sort exception table */ mod->extable = section_objs(hdr, sechdrs, secstrings, "__ex_table", @@ -2541,28 +2589,9 @@ static noinline struct module *load_module(void __user *umod, if (err < 0) goto cleanup; - /* flush the icache in correct context */ - old_fs = get_fs(); - set_fs(KERNEL_DS); - - /* - * Flush the instruction cache, since we've played with text. - * Do it before processing of module parameters, so the module - * can provide parameter accessor functions of its own. - */ - if (mod->module_init) - flush_icache_range((unsigned long)mod->module_init, - (unsigned long)mod->module_init - + mod->init_size); - flush_icache_range((unsigned long)mod->module_core, - (unsigned long)mod->module_core + mod->core_size); - - set_fs(old_fs); + flush_module_icache(mod); mod->args = args; - if (section_addr(hdr, sechdrs, secstrings, "__obsparm")) - printk(KERN_WARNING "%s: Ignoring obsolete parameters\n", - mod->name); /* Now sew it into the lists so we can get lockdep and oops * info during argument parsing. Noone should access us, since @@ -2619,6 +2648,7 @@ static noinline struct module *load_module(void __user *umod, module_arch_cleanup(mod); cleanup: free_modinfo(mod); + free_unload: module_unload_free(mod); free_init: module_free(mod, mod->module_init); -- 2.39.5