Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756239AbYJUXGS (ORCPT ); Tue, 21 Oct 2008 19:06:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751972AbYJUXGI (ORCPT ); Tue, 21 Oct 2008 19:06:08 -0400 Received: from ozlabs.org ([203.10.76.45]:42294 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751908AbYJUXGD (ORCPT ); Tue, 21 Oct 2008 19:06:03 -0400 From: Rusty Russell To: Linus Torvalds Subject: [PULL] module, param and stop_machine patches Date: Wed, 22 Oct 2008 10:05:58 +1100 User-Agent: KMail/1.9.10 Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Andi Kleen , Heiko Carstens , "Greg Kroah-Hartman" , Arjan van de Ven MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200810221005.59874.rusty@rustcorp.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 43713 Lines: 1329 The following changes since commit 2515ddc6db8eb49a79f0fe5e67ff09ac7c81eab4: Paul Mundt (1): binfmt_elf_fdpic: Update for cputime changes. are available in the git repository at: ssh://master.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus.git master Andi Kleen (1): Remove stop_machine during module load v2 Heiko Carstens (4): Call init_workqueues before pre smp initcalls. workqueue: introduce create_rt_workqueue stop_machine: use workqueues instead of kernel threads stop_machine: fix error code handling on multiple cpus Rusty Russell (6): module: simplify load_module. module: check kernel param length at compile time, not runtime param: Fix duplicate module prefixes core_param() for genuinely core kernel parameters Make initcall_debug a core_param Make panic= and panic_on_oops into core_params include/linux/module.h | 6 +- include/linux/moduleparam.h | 25 ++++- include/linux/workqueue.h | 18 ++-- init/main.c | 12 +-- kernel/module.c | 284 ++++++++++++++++++------------------------ kernel/panic.c | 17 +-- kernel/params.c | 274 ++++++++++++++++++++++------------------- kernel/stop_machine.c | 120 +++++++----------- kernel/workqueue.c | 7 +- 9 files changed, 364 insertions(+), 399 deletions(-) diff --git a/include/linux/module.h b/include/linux/module.h index 5d2970c..3bfed01 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -29,7 +29,7 @@ #define MODULE_SYMBOL_PREFIX "" #endif -#define MODULE_NAME_LEN (64 - sizeof(unsigned long)) +#define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN struct kernel_symbol { @@ -60,6 +60,7 @@ struct module_kobject struct kobject kobj; struct module *mod; struct kobject *drivers_dir; + struct module_param_attrs *mp; }; /* These are either module local, or the kernel's dummy ones. */ @@ -242,7 +243,6 @@ struct module /* Sysfs stuff. */ struct module_kobject mkobj; - struct module_param_attrs *param_attrs; struct module_attribute *modinfo_attrs; const char *version; const char *srcversion; @@ -277,7 +277,7 @@ struct module /* Exception table */ unsigned int num_exentries; - const struct exception_table_entry *extable; + struct exception_table_entry *extable; /* Startup function. */ int (*init)(void); diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index ec62438..e4af339 100644 --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -13,6 +13,9 @@ #define MODULE_PARAM_PREFIX KBUILD_MODNAME "." #endif +/* Chosen so that structs with an unsigned long line up. */ +#define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long)) + #ifdef MODULE #define ___module_cat(a,b) __mod_ ## a ## b #define __module_cat(a,b) ___module_cat(a,b) @@ -79,7 +82,8 @@ struct kparam_array #define __module_param_call(prefix, name, set, get, arg, perm) \ /* Default value instead of permissions? */ \ static int __param_perm_check_##name __attribute__((unused)) = \ - BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)); \ + BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)) \ + + BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN); \ static const char __param_str_##name[] = prefix #name; \ static struct kernel_param __moduleparam_const __param_##name \ __used \ @@ -100,6 +104,25 @@ struct kparam_array #define module_param(name, type, perm) \ module_param_named(name, name, type, perm) +#ifndef MODULE +/** + * core_param - define a historical core kernel parameter. + * @name: the name of the cmdline and sysfs parameter (often the same as var) + * @var: the variable + * @type: the type (for param_set_##type and param_get_##type) + * @perm: visibility in sysfs + * + * core_param is just like module_param(), but cannot be modular and + * doesn't add a prefix (such as "printk."). This is for compatibility + * with __setup(), and it makes sense as truly core parameters aren't + * tied to the particular file they're in. + */ +#define core_param(name, var, type, perm) \ + param_check_##type(name, &(var)); \ + __module_param_call("", name, param_set_##type, param_get_##type, \ + &var, perm) +#endif /* !MODULE */ + /* Actually copy string: maxlen param is usually sizeof(string). */ #define module_param_string(name, string, len, perm) \ static const struct kparam_string __param_string_##name \ diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 5c158c4..89a5a12 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -149,11 +149,11 @@ struct execute_work { extern struct workqueue_struct * __create_workqueue_key(const char *name, int singlethread, - int freezeable, struct lock_class_key *key, + int freezeable, int rt, struct lock_class_key *key, const char *lock_name); #ifdef CONFIG_LOCKDEP -#define __create_workqueue(name, singlethread, freezeable) \ +#define __create_workqueue(name, singlethread, freezeable, rt) \ ({ \ static struct lock_class_key __key; \ const char *__lock_name; \ @@ -164,17 +164,19 @@ __create_workqueue_key(const char *name, int singlethread, __lock_name = #name; \ \ __create_workqueue_key((name), (singlethread), \ - (freezeable), &__key, \ + (freezeable), (rt), &__key, \ __lock_name); \ }) #else -#define __create_workqueue(name, singlethread, freezeable) \ - __create_workqueue_key((name), (singlethread), (freezeable), NULL, NULL) +#define __create_workqueue(name, singlethread, freezeable, rt) \ + __create_workqueue_key((name), (singlethread), (freezeable), (rt), \ + NULL, NULL) #endif -#define create_workqueue(name) __create_workqueue((name), 0, 0) -#define create_freezeable_workqueue(name) __create_workqueue((name), 1, 1) -#define create_singlethread_workqueue(name) __create_workqueue((name), 1, 0) +#define create_workqueue(name) __create_workqueue((name), 0, 0, 0) +#define create_rt_workqueue(name) __create_workqueue((name), 0, 0, 1) +#define create_freezeable_workqueue(name) __create_workqueue((name), 1, 1, 0) +#define create_singlethread_workqueue(name) __create_workqueue((name), 1, 0, 0) extern void destroy_workqueue(struct workqueue_struct *wq); diff --git a/init/main.c b/init/main.c index 3e17a3b..6c7fd13 100644 --- a/init/main.c +++ b/init/main.c @@ -697,13 +697,7 @@ asmlinkage void __init start_kernel(void) } static int initcall_debug; - -static int __init initcall_debug_setup(char *str) -{ - initcall_debug = 1; - return 1; -} -__setup("initcall_debug", initcall_debug_setup); +core_param(initcall_debug, initcall_debug, bool, 0644); int do_one_initcall(initcall_t fn) { @@ -773,8 +767,6 @@ static void __init do_initcalls(void) static void __init do_basic_setup(void) { rcu_init_sched(); /* needed by module_init stage. */ - /* drivers will send hotplug events */ - init_workqueues(); usermodehelper_init(); driver_init(); init_irq_proc(); @@ -858,6 +850,8 @@ static int __init kernel_init(void * unused) cad_pid = task_pid(current); + init_workqueues(); + smp_prepare_cpus(setup_max_cpus); do_pre_smp_initcalls(); diff --git a/kernel/module.c b/kernel/module.c index 0d8d21e..c0f1826 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -42,6 +42,7 @@ #include #include #include +#include #include #include #include @@ -63,7 +64,7 @@ #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1)) /* List of modules, protected by module_mutex or preempt_disable - * (add/delete uses stop_machine). */ + * (delete uses stop_machine/add uses RCU list operations). */ static DEFINE_MUTEX(module_mutex); static LIST_HEAD(modules); @@ -132,6 +133,29 @@ static unsigned int find_sec(Elf_Ehdr *hdr, return 0; } +/* Find a module section, or NULL. */ +static void *section_addr(Elf_Ehdr *hdr, Elf_Shdr *shdrs, + const char *secstrings, const char *name) +{ + /* Section 0 has sh_addr 0. */ + return (void *)shdrs[find_sec(hdr, shdrs, secstrings, name)].sh_addr; +} + +/* Find a module section, or NULL. Fill in number of "objects" in section. */ +static void *section_objs(Elf_Ehdr *hdr, + Elf_Shdr *sechdrs, + const char *secstrings, + const char *name, + size_t object_size, + unsigned int *num) +{ + unsigned int sec = find_sec(hdr, sechdrs, secstrings, name); + + /* Section 0 has sh_addr 0 and sh_size 0. */ + *num = sechdrs[sec].sh_size / object_size; + return (void *)sechdrs[sec].sh_addr; +} + /* Provided by the linker */ extern const struct kernel_symbol __start___ksymtab[]; extern const struct kernel_symbol __stop___ksymtab[]; @@ -218,7 +242,7 @@ static bool each_symbol(bool (*fn)(const struct symsearch *arr, if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data)) return true; - list_for_each_entry(mod, &modules, list) { + list_for_each_entry_rcu(mod, &modules, list) { struct symsearch arr[] = { { mod->syms, mod->syms + mod->num_syms, mod->crcs, NOT_GPL_ONLY, false }, @@ -1394,17 +1418,6 @@ static void mod_kobject_remove(struct module *mod) } /* - * link the module with the whole machine is stopped with interrupts off - * - this defends against kallsyms not taking locks - */ -static int __link_module(void *_mod) -{ - struct module *mod = _mod; - list_add(&mod->list, &modules); - return 0; -} - -/* * unlink the module with the whole machine is stopped with interrupts off * - this defends against kallsyms not taking locks */ @@ -1789,32 +1802,20 @@ static inline void add_kallsyms(struct module *mod, } #endif /* CONFIG_KALLSYMS */ -#ifdef CONFIG_DYNAMIC_PRINTK_DEBUG -static void dynamic_printk_setup(Elf_Shdr *sechdrs, unsigned int verboseindex) +static void dynamic_printk_setup(struct mod_debug *debug, unsigned int num) { - struct mod_debug *debug_info; - unsigned long pos, end; - unsigned int num_verbose; - - pos = sechdrs[verboseindex].sh_addr; - num_verbose = sechdrs[verboseindex].sh_size / - sizeof(struct mod_debug); - end = pos + (num_verbose * sizeof(struct mod_debug)); +#ifdef CONFIG_DYNAMIC_PRINTK_DEBUG + unsigned int i; - for (; pos < end; pos += sizeof(struct mod_debug)) { - debug_info = (struct mod_debug *)pos; - register_dynamic_debug_module(debug_info->modname, - debug_info->type, debug_info->logical_modname, - debug_info->flag_names, debug_info->hash, - debug_info->hash2); + for (i = 0; i < num; i++) { + register_dynamic_debug_module(debug[i].modname, + debug[i].type, + debug[i].logical_modname, + debug[i].flag_names, + debug[i].hash, debug[i].hash2); } -} -#else -static inline void dynamic_printk_setup(Elf_Shdr *sechdrs, - unsigned int verboseindex) -{ -} #endif /* CONFIG_DYNAMIC_PRINTK_DEBUG */ +} static void *module_alloc_update_bounds(unsigned long size) { @@ -1843,37 +1844,14 @@ static noinline struct module *load_module(void __user *umod, unsigned int i; unsigned int symindex = 0; unsigned int strindex = 0; - unsigned int setupindex; - unsigned int exindex; - unsigned int exportindex; - unsigned int modindex; - unsigned int obsparmindex; - unsigned int infoindex; - unsigned int gplindex; - unsigned int crcindex; - unsigned int gplcrcindex; - unsigned int versindex; - unsigned int pcpuindex; - unsigned int gplfutureindex; - unsigned int gplfuturecrcindex; + unsigned int modindex, versindex, infoindex, pcpuindex; unsigned int unwindex = 0; -#ifdef CONFIG_UNUSED_SYMBOLS - unsigned int unusedindex; - unsigned int unusedcrcindex; - unsigned int unusedgplindex; - unsigned int unusedgplcrcindex; -#endif - unsigned int markersindex; - unsigned int markersstringsindex; - unsigned int verboseindex; - unsigned int tracepointsindex; - unsigned int tracepointsstringsindex; - unsigned int mcountindex; + unsigned int num_kp, num_mcount; + struct kernel_param *kp; struct module *mod; long err = 0; void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */ - void *mseg; - struct exception_table_entry *extable; + unsigned long *mseg; mm_segment_t old_fs; DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n", @@ -1937,6 +1915,7 @@ static noinline struct module *load_module(void __user *umod, err = -ENOEXEC; goto free_hdr; } + /* This is temporary: point mod into copy of data. */ mod = (void *)sechdrs[modindex].sh_addr; if (symindex == 0) { @@ -1946,22 +1925,6 @@ static noinline struct module *load_module(void __user *umod, goto free_hdr; } - /* Optional sections */ - exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab"); - gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl"); - gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future"); - crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab"); - gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl"); - gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future"); -#ifdef CONFIG_UNUSED_SYMBOLS - unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused"); - unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl"); - unusedcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused"); - unusedgplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl"); -#endif - setupindex = find_sec(hdr, sechdrs, secstrings, "__param"); - exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table"); - obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm"); versindex = find_sec(hdr, sechdrs, secstrings, "__versions"); infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo"); pcpuindex = find_pcpusec(hdr, sechdrs, secstrings); @@ -2117,42 +2080,57 @@ static noinline struct module *load_module(void __user *umod, if (err < 0) goto cleanup; - /* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */ - mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms); - mod->syms = (void *)sechdrs[exportindex].sh_addr; - if (crcindex) - mod->crcs = (void *)sechdrs[crcindex].sh_addr; - mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms); - mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr; - if (gplcrcindex) - mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr; - mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size / - sizeof(*mod->gpl_future_syms); - mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr; - if (gplfuturecrcindex) - mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr; + /* Now we've got everything in the final locations, we can + * find optional sections. */ + kp = section_objs(hdr, sechdrs, secstrings, "__param", sizeof(*kp), + &num_kp); + mod->syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab", + sizeof(*mod->syms), &mod->num_syms); + mod->crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab"); + mod->gpl_syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab_gpl", + sizeof(*mod->gpl_syms), + &mod->num_gpl_syms); + mod->gpl_crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab_gpl"); + mod->gpl_future_syms = section_objs(hdr, sechdrs, secstrings, + "__ksymtab_gpl_future", + sizeof(*mod->gpl_future_syms), + &mod->num_gpl_future_syms); + mod->gpl_future_crcs = section_addr(hdr, sechdrs, secstrings, + "__kcrctab_gpl_future"); #ifdef CONFIG_UNUSED_SYMBOLS - mod->num_unused_syms = sechdrs[unusedindex].sh_size / - sizeof(*mod->unused_syms); - mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size / - sizeof(*mod->unused_gpl_syms); - mod->unused_syms = (void *)sechdrs[unusedindex].sh_addr; - if (unusedcrcindex) - mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr; - mod->unused_gpl_syms = (void *)sechdrs[unusedgplindex].sh_addr; - if (unusedgplcrcindex) - mod->unused_gpl_crcs - = (void *)sechdrs[unusedgplcrcindex].sh_addr; + mod->unused_syms = section_objs(hdr, sechdrs, secstrings, + "__ksymtab_unused", + sizeof(*mod->unused_syms), + &mod->num_unused_syms); + mod->unused_crcs = section_addr(hdr, sechdrs, secstrings, + "__kcrctab_unused"); + mod->unused_gpl_syms = section_objs(hdr, sechdrs, secstrings, + "__ksymtab_unused_gpl", + sizeof(*mod->unused_gpl_syms), + &mod->num_unused_gpl_syms); + mod->unused_gpl_crcs = section_addr(hdr, sechdrs, secstrings, + "__kcrctab_unused_gpl"); +#endif + +#ifdef CONFIG_MARKERS + mod->markers = section_objs(hdr, sechdrs, secstrings, "__markers", + sizeof(*mod->markers), &mod->num_markers); +#endif +#ifdef CONFIG_TRACEPOINTS + mod->tracepoints = section_objs(hdr, sechdrs, secstrings, + "__tracepoints", + sizeof(*mod->tracepoints), + &mod->num_tracepoints); #endif #ifdef CONFIG_MODVERSIONS - if ((mod->num_syms && !crcindex) - || (mod->num_gpl_syms && !gplcrcindex) - || (mod->num_gpl_future_syms && !gplfuturecrcindex) + 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 && !unusedcrcindex) - || (mod->num_unused_gpl_syms && !unusedgplcrcindex) + || (mod->num_unused_syms && !mod->unused_crcs) + || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs) #endif ) { printk(KERN_WARNING "%s: No versions for exported symbols.\n", mod->name); @@ -2161,16 +2139,6 @@ static noinline struct module *load_module(void __user *umod, goto cleanup; } #endif - markersindex = find_sec(hdr, sechdrs, secstrings, "__markers"); - markersstringsindex = find_sec(hdr, sechdrs, secstrings, - "__markers_strings"); - verboseindex = find_sec(hdr, sechdrs, secstrings, "__verbose"); - tracepointsindex = find_sec(hdr, sechdrs, secstrings, "__tracepoints"); - tracepointsstringsindex = find_sec(hdr, sechdrs, secstrings, - "__tracepoints_strings"); - - mcountindex = find_sec(hdr, sechdrs, secstrings, - "__mcount_loc"); /* Now do relocations. */ for (i = 1; i < hdr->e_shnum; i++) { @@ -2193,28 +2161,16 @@ static noinline struct module *load_module(void __user *umod, if (err < 0) goto cleanup; } -#ifdef CONFIG_MARKERS - mod->markers = (void *)sechdrs[markersindex].sh_addr; - mod->num_markers = - sechdrs[markersindex].sh_size / sizeof(*mod->markers); -#endif -#ifdef CONFIG_TRACEPOINTS - mod->tracepoints = (void *)sechdrs[tracepointsindex].sh_addr; - mod->num_tracepoints = - sechdrs[tracepointsindex].sh_size / sizeof(*mod->tracepoints); -#endif - /* Find duplicate symbols */ err = verify_export_symbols(mod); - if (err < 0) goto cleanup; /* Set up and sort exception table */ - mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable); - mod->extable = extable = (void *)sechdrs[exindex].sh_addr; - sort_extable(extable, extable + mod->num_exentries); + mod->extable = section_objs(hdr, sechdrs, secstrings, "__ex_table", + sizeof(*mod->extable), &mod->num_exentries); + sort_extable(mod->extable, mod->extable + mod->num_exentries); /* Finally, copy percpu area over. */ percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr, @@ -2223,11 +2179,17 @@ static noinline struct module *load_module(void __user *umod, add_kallsyms(mod, sechdrs, symindex, strindex, secstrings); if (!mod->taints) { + struct mod_debug *debug; + unsigned int num_debug; + #ifdef CONFIG_MARKERS marker_update_probe_range(mod->markers, mod->markers + mod->num_markers); #endif - dynamic_printk_setup(sechdrs, verboseindex); + debug = section_objs(hdr, sechdrs, secstrings, "__verbose", + sizeof(*debug), &num_debug); + dynamic_printk_setup(debug, num_debug); + #ifdef CONFIG_TRACEPOINTS tracepoint_update_probe_range(mod->tracepoints, mod->tracepoints + mod->num_tracepoints); @@ -2235,8 +2197,9 @@ static noinline struct module *load_module(void __user *umod, } /* sechdrs[0].sh_size is always zero */ - mseg = (void *)sechdrs[mcountindex].sh_addr; - ftrace_init_module(mseg, mseg + sechdrs[mcountindex].sh_size); + mseg = section_objs(hdr, sechdrs, secstrings, "__mcount_loc", + sizeof(*mseg), &num_mcount); + ftrace_init_module(mseg, mseg + num_mcount); err = module_finalize(hdr, sechdrs, mod); if (err < 0) @@ -2261,30 +2224,24 @@ static noinline struct module *load_module(void __user *umod, set_fs(old_fs); mod->args = args; - if (obsparmindex) + 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 - * strong_try_module_get() will fail. */ - stop_machine(__link_module, mod, NULL); - - /* Size of section 0 is 0, so this works well if no params */ - err = parse_args(mod->name, mod->args, - (struct kernel_param *) - sechdrs[setupindex].sh_addr, - sechdrs[setupindex].sh_size - / sizeof(struct kernel_param), - NULL); + * info during argument parsing. Noone should access us, since + * strong_try_module_get() will fail. + * lockdep/oops can run asynchronous, so use the RCU list insertion + * function to insert in a way safe to concurrent readers. + * The mutex protects against concurrent writers. + */ + list_add_rcu(&mod->list, &modules); + + err = parse_args(mod->name, mod->args, kp, num_kp, NULL); if (err < 0) goto unlink; - err = mod_sysfs_setup(mod, - (struct kernel_param *) - sechdrs[setupindex].sh_addr, - sechdrs[setupindex].sh_size - / sizeof(struct kernel_param)); + err = mod_sysfs_setup(mod, kp, num_kp); if (err < 0) goto unlink; add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs); @@ -2473,7 +2430,7 @@ const char *module_address_lookup(unsigned long addr, const char *ret = NULL; preempt_disable(); - list_for_each_entry(mod, &modules, list) { + list_for_each_entry_rcu(mod, &modules, list) { if (within(addr, mod->module_init, mod->init_size) || within(addr, mod->module_core, mod->core_size)) { if (modname) @@ -2496,7 +2453,7 @@ int lookup_module_symbol_name(unsigned long addr, char *symname) struct module *mod; preempt_disable(); - list_for_each_entry(mod, &modules, list) { + list_for_each_entry_rcu(mod, &modules, list) { if (within(addr, mod->module_init, mod->init_size) || within(addr, mod->module_core, mod->core_size)) { const char *sym; @@ -2520,7 +2477,7 @@ int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, struct module *mod; preempt_disable(); - list_for_each_entry(mod, &modules, list) { + list_for_each_entry_rcu(mod, &modules, list) { if (within(addr, mod->module_init, mod->init_size) || within(addr, mod->module_core, mod->core_size)) { const char *sym; @@ -2547,7 +2504,7 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, struct module *mod; preempt_disable(); - list_for_each_entry(mod, &modules, list) { + list_for_each_entry_rcu(mod, &modules, list) { if (symnum < mod->num_symtab) { *value = mod->symtab[symnum].st_value; *type = mod->symtab[symnum].st_info; @@ -2590,7 +2547,7 @@ unsigned long module_kallsyms_lookup_name(const char *name) ret = mod_find_symname(mod, colon+1); *colon = ':'; } else { - list_for_each_entry(mod, &modules, list) + list_for_each_entry_rcu(mod, &modules, list) if ((ret = mod_find_symname(mod, name)) != 0) break; } @@ -2693,7 +2650,7 @@ const struct exception_table_entry *search_module_extables(unsigned long addr) struct module *mod; preempt_disable(); - list_for_each_entry(mod, &modules, list) { + list_for_each_entry_rcu(mod, &modules, list) { if (mod->num_exentries == 0) continue; @@ -2719,7 +2676,7 @@ int is_module_address(unsigned long addr) preempt_disable(); - list_for_each_entry(mod, &modules, list) { + list_for_each_entry_rcu(mod, &modules, list) { if (within(addr, mod->module_core, mod->core_size)) { preempt_enable(); return 1; @@ -2740,7 +2697,7 @@ struct module *__module_text_address(unsigned long addr) if (addr < module_addr_min || addr > module_addr_max) return NULL; - list_for_each_entry(mod, &modules, list) + list_for_each_entry_rcu(mod, &modules, list) if (within(addr, mod->module_init, mod->init_text_size) || within(addr, mod->module_core, mod->core_text_size)) return mod; @@ -2765,8 +2722,11 @@ void print_modules(void) char buf[8]; printk("Modules linked in:"); - list_for_each_entry(mod, &modules, list) + /* Most callers should already have preempt disabled, but make sure */ + preempt_disable(); + list_for_each_entry_rcu(mod, &modules, list) printk(" %s%s", mod->name, module_flags(mod, buf)); + preempt_enable(); if (last_unloaded_module[0]) printk(" [last unloaded: %s]", last_unloaded_module); printk("\n"); diff --git a/kernel/panic.c b/kernel/panic.c index bda561e..6513aac 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -34,13 +34,6 @@ ATOMIC_NOTIFIER_HEAD(panic_notifier_list); EXPORT_SYMBOL(panic_notifier_list); -static int __init panic_setup(char *str) -{ - panic_timeout = simple_strtoul(str, NULL, 0); - return 1; -} -__setup("panic=", panic_setup); - static long no_blink(long time) { return 0; @@ -218,13 +211,6 @@ void add_taint(unsigned flag) } EXPORT_SYMBOL(add_taint); -static int __init pause_on_oops_setup(char *str) -{ - pause_on_oops = simple_strtoul(str, NULL, 0); - return 1; -} -__setup("pause_on_oops=", pause_on_oops_setup); - static void spin_msec(int msecs) { int i; @@ -384,3 +370,6 @@ void __stack_chk_fail(void) } EXPORT_SYMBOL(__stack_chk_fail); #endif + +core_param(panic, panic_timeout, int, 0644); +core_param(pause_on_oops, pause_on_oops, int, 0644); diff --git a/kernel/params.c b/kernel/params.c index afc46a2..b077f1b 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -373,6 +373,8 @@ int param_get_string(char *buffer, struct kernel_param *kp) } /* sysfs output in /sys/modules/XYZ/parameters/ */ +#define to_module_attr(n) container_of(n, struct module_attribute, attr); +#define to_module_kobject(n) container_of(n, struct module_kobject, kobj); extern struct kernel_param __start___param[], __stop___param[]; @@ -384,6 +386,7 @@ struct param_attribute struct module_param_attrs { + unsigned int num; struct attribute_group grp; struct param_attribute attrs[0]; }; @@ -434,69 +437,84 @@ static ssize_t param_attr_store(struct module_attribute *mattr, #ifdef CONFIG_SYSFS /* - * param_sysfs_setup - setup sysfs support for one module or KBUILD_MODNAME - * @mk: struct module_kobject (contains parent kobject) - * @kparam: array of struct kernel_param, the actual parameter definitions - * @num_params: number of entries in array - * @name_skip: offset where the parameter name start in kparam[].name. Needed for built-in "modules" + * add_sysfs_param - add a parameter to sysfs + * @mk: struct module_kobject + * @kparam: the actual parameter definition to add to sysfs + * @name: name of parameter * - * Create a kobject for a (per-module) group of parameters, and create files - * in sysfs. A pointer to the param_kobject is returned on success, - * NULL if there's no parameter to export, or other ERR_PTR(err). + * Create a kobject if for a (per-module) parameter if mp NULL, and + * create file in sysfs. Returns an error on out of memory. Always cleans up + * if there's an error. */ -static __modinit struct module_param_attrs * -param_sysfs_setup(struct module_kobject *mk, - struct kernel_param *kparam, - unsigned int num_params, - unsigned int name_skip) +static __modinit int add_sysfs_param(struct module_kobject *mk, + struct kernel_param *kp, + const char *name) { - struct module_param_attrs *mp; - unsigned int valid_attrs = 0; - unsigned int i, size[2]; - struct param_attribute *pattr; - struct attribute **gattr; - int err; - - for (i=0; iperm); + + if (!mk->mp) { + num = 0; + attrs = NULL; + } else { + num = mk->mp->num; + attrs = mk->mp->grp.attrs; } - if (!valid_attrs) - return NULL; - - size[0] = ALIGN(sizeof(*mp) + - valid_attrs * sizeof(mp->attrs[0]), - sizeof(mp->grp.attrs[0])); - size[1] = (valid_attrs + 1) * sizeof(mp->grp.attrs[0]); - - mp = kzalloc(size[0] + size[1], GFP_KERNEL); - if (!mp) - return ERR_PTR(-ENOMEM); + /* Enlarge. */ + new = krealloc(mk->mp, + sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1), + GFP_KERNEL); + if (!new) { + kfree(mk->mp); + err = -ENOMEM; + goto fail; + } + attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL); + if (!attrs) { + err = -ENOMEM; + goto fail_free_new; + } - mp->grp.name = "parameters"; - mp->grp.attrs = (void *)mp + size[0]; + /* Sysfs wants everything zeroed. */ + memset(new, 0, sizeof(*new)); + memset(&new->attrs[num], 0, sizeof(new->attrs[num])); + memset(&attrs[num], 0, sizeof(attrs[num])); + new->grp.name = "parameters"; + new->grp.attrs = attrs; + + /* Tack new one on the end. */ + new->attrs[num].param = kp; + new->attrs[num].mattr.show = param_attr_show; + new->attrs[num].mattr.store = param_attr_store; + new->attrs[num].mattr.attr.name = (char *)name; + new->attrs[num].mattr.attr.mode = kp->perm; + new->num = num+1; + + /* Fix up all the pointers, since krealloc can move us */ + for (num = 0; num < new->num; num++) + new->grp.attrs[num] = &new->attrs[num].mattr.attr; + new->grp.attrs[num] = NULL; + + mk->mp = new; + return 0; - pattr = &mp->attrs[0]; - gattr = &mp->grp.attrs[0]; - for (i = 0; i < num_params; i++) { - struct kernel_param *kp = &kparam[i]; - if (kp->perm) { - pattr->param = kp; - pattr->mattr.show = param_attr_show; - pattr->mattr.store = param_attr_store; - pattr->mattr.attr.name = (char *)&kp->name[name_skip]; - pattr->mattr.attr.mode = kp->perm; - *(gattr++) = &(pattr++)->mattr.attr; - } - } - *gattr = NULL; +fail_free_new: + kfree(new); +fail: + mk->mp = NULL; + return err; +} - if ((err = sysfs_create_group(&mk->kobj, &mp->grp))) { - kfree(mp); - return ERR_PTR(err); - } - return mp; +static void free_module_param_attrs(struct module_kobject *mk) +{ + kfree(mk->mp->grp.attrs); + kfree(mk->mp); + mk->mp = NULL; } #ifdef CONFIG_MODULES @@ -506,21 +524,33 @@ param_sysfs_setup(struct module_kobject *mk, * @kparam: module parameters (array) * @num_params: number of module parameters * - * Adds sysfs entries for module parameters, and creates a link from - * /sys/module/[mod->name]/parameters to /sys/parameters/[mod->name]/ + * Adds sysfs entries for module parameters under + * /sys/module/[mod->name]/parameters/ */ int module_param_sysfs_setup(struct module *mod, struct kernel_param *kparam, unsigned int num_params) { - struct module_param_attrs *mp; + int i, err; + bool params = false; + + for (i = 0; i < num_params; i++) { + if (kparam[i].perm == 0) + continue; + err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name); + if (err) + return err; + params = true; + } - mp = param_sysfs_setup(&mod->mkobj, kparam, num_params, 0); - if (IS_ERR(mp)) - return PTR_ERR(mp); + if (!params) + return 0; - mod->param_attrs = mp; - return 0; + /* Create the param group. */ + err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp); + if (err) + free_module_param_attrs(&mod->mkobj); + return err; } /* @@ -532,43 +562,55 @@ int module_param_sysfs_setup(struct module *mod, */ void module_param_sysfs_remove(struct module *mod) { - if (mod->param_attrs) { - sysfs_remove_group(&mod->mkobj.kobj, - &mod->param_attrs->grp); + if (mod->mkobj.mp) { + sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp); /* We are positive that no one is using any param * attrs at this point. Deallocate immediately. */ - kfree(mod->param_attrs); - mod->param_attrs = NULL; + free_module_param_attrs(&mod->mkobj); } } #endif -/* - * kernel_param_sysfs_setup - wrapper for built-in params support - */ -static void __init kernel_param_sysfs_setup(const char *name, - struct kernel_param *kparam, - unsigned int num_params, - unsigned int name_skip) +static void __init kernel_add_sysfs_param(const char *name, + struct kernel_param *kparam, + unsigned int name_skip) { struct module_kobject *mk; - int ret; + struct kobject *kobj; + int err; - mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL); - BUG_ON(!mk); - - mk->mod = THIS_MODULE; - mk->kobj.kset = module_kset; - ret = kobject_init_and_add(&mk->kobj, &module_ktype, NULL, "%s", name); - if (ret) { - kobject_put(&mk->kobj); - printk(KERN_ERR "Module '%s' failed to be added to sysfs, " - "error number %d\n", name, ret); - printk(KERN_ERR "The system will be unstable now.\n"); - return; + kobj = kset_find_obj(module_kset, name); + if (kobj) { + /* We already have one. Remove params so we can add more. */ + mk = to_module_kobject(kobj); + /* We need to remove it before adding parameters. */ + sysfs_remove_group(&mk->kobj, &mk->mp->grp); + } else { + mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL); + BUG_ON(!mk); + + mk->mod = THIS_MODULE; + mk->kobj.kset = module_kset; + err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL, + "%s", name); + if (err) { + kobject_put(&mk->kobj); + printk(KERN_ERR "Module '%s' failed add to sysfs, " + "error number %d\n", name, err); + printk(KERN_ERR "The system will be unstable now.\n"); + return; + } + /* So that exit path is even. */ + kobject_get(&mk->kobj); } - param_sysfs_setup(mk, kparam, num_params, name_skip); + + /* These should not fail at boot. */ + err = add_sysfs_param(mk, kparam, kparam->name + name_skip); + BUG_ON(err); + err = sysfs_create_group(&mk->kobj, &mk->mp->grp); + BUG_ON(err); kobject_uevent(&mk->kobj, KOBJ_ADD); + kobject_put(&mk->kobj); } /* @@ -579,60 +621,36 @@ static void __init kernel_param_sysfs_setup(const char *name, * The "module" name (KBUILD_MODNAME) is stored before a dot, the * "parameter" name is stored behind a dot in kernel_param->name. So, * extract the "module" name for all built-in kernel_param-eters, - * and for all who have the same, call kernel_param_sysfs_setup. + * and for all who have the same, call kernel_add_sysfs_param. */ static void __init param_sysfs_builtin(void) { - struct kernel_param *kp, *kp_begin = NULL; - unsigned int i, name_len, count = 0; - char modname[MODULE_NAME_LEN + 1] = ""; + struct kernel_param *kp; + unsigned int name_len; + char modname[MODULE_NAME_LEN]; - for (i=0; i < __stop___param - __start___param; i++) { + for (kp = __start___param; kp < __stop___param; kp++) { char *dot; - size_t max_name_len; - kp = &__start___param[i]; - max_name_len = - min_t(size_t, MODULE_NAME_LEN, strlen(kp->name)); + if (kp->perm == 0) + continue; - dot = memchr(kp->name, '.', max_name_len); + dot = strchr(kp->name, '.'); if (!dot) { - DEBUGP("couldn't find period in first %d characters " - "of %s\n", MODULE_NAME_LEN, kp->name); - continue; - } - name_len = dot - kp->name; - - /* new kbuild_modname? */ - if (strlen(modname) != name_len - || strncmp(modname, kp->name, name_len) != 0) { - /* add a new kobject for previous kernel_params. */ - if (count) - kernel_param_sysfs_setup(modname, - kp_begin, - count, - strlen(modname)+1); - - strncpy(modname, kp->name, name_len); - modname[name_len] = '\0'; - count = 0; - kp_begin = kp; + /* This happens for core_param() */ + strcpy(modname, "kernel"); + name_len = 0; + } else { + name_len = dot - kp->name + 1; + strlcpy(modname, kp->name, name_len); } - count++; + kernel_add_sysfs_param(modname, kp, name_len); } - - /* last kernel_params need to be registered as well */ - if (count) - kernel_param_sysfs_setup(modname, kp_begin, count, - strlen(modname)+1); } /* module-related sysfs stuff */ -#define to_module_attr(n) container_of(n, struct module_attribute, attr); -#define to_module_kobject(n) container_of(n, struct module_kobject, kobj); - static ssize_t module_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index af3c7ce..8aff79d 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -37,9 +37,13 @@ struct stop_machine_data { /* Like num_online_cpus(), but hotplug cpu uses us, so we need this. */ static unsigned int num_threads; static atomic_t thread_ack; -static struct completion finished; static DEFINE_MUTEX(lock); +static struct workqueue_struct *stop_machine_wq; +static struct stop_machine_data active, idle; +static const cpumask_t *active_cpus; +static void *stop_machine_work; + static void set_state(enum stopmachine_state newstate) { /* Reset ack counter. */ @@ -51,21 +55,26 @@ static void set_state(enum stopmachine_state newstate) /* Last one to ack a state moves to the next state. */ static void ack_state(void) { - if (atomic_dec_and_test(&thread_ack)) { - /* If we're the last one to ack the EXIT, we're finished. */ - if (state == STOPMACHINE_EXIT) - complete(&finished); - else - set_state(state + 1); - } + if (atomic_dec_and_test(&thread_ack)) + set_state(state + 1); } -/* This is the actual thread which stops the CPU. It exits by itself rather - * than waiting for kthread_stop(), because it's easier for hotplug CPU. */ -static int stop_cpu(struct stop_machine_data *smdata) +/* This is the actual function which stops the CPU. It runs + * in the context of a dedicated stopmachine workqueue. */ +static void stop_cpu(struct work_struct *unused) { enum stopmachine_state curstate = STOPMACHINE_NONE; - + struct stop_machine_data *smdata = &idle; + int cpu = smp_processor_id(); + int err; + + if (!active_cpus) { + if (cpu == first_cpu(cpu_online_map)) + smdata = &active; + } else { + if (cpu_isset(cpu, *active_cpus)) + smdata = &active; + } /* Simple state machine */ do { /* Chill out and ensure we re-read stopmachine_state. */ @@ -78,9 +87,11 @@ static int stop_cpu(struct stop_machine_data *smdata) hard_irq_disable(); break; case STOPMACHINE_RUN: - /* |= allows error detection if functions on - * multiple CPUs. */ - smdata->fnret |= smdata->fn(smdata->data); + /* On multiple CPUs only a single error code + * is needed to tell that something failed. */ + err = smdata->fn(smdata->data); + if (err) + smdata->fnret = err; break; default: break; @@ -90,7 +101,6 @@ static int stop_cpu(struct stop_machine_data *smdata) } while (curstate != STOPMACHINE_EXIT); local_irq_enable(); - do_exit(0); } /* Callback for CPUs which aren't supposed to do anything. */ @@ -101,78 +111,34 @@ static int chill(void *unused) int __stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus) { - int i, err; - struct stop_machine_data active, idle; - struct task_struct **threads; + struct work_struct *sm_work; + int i; + /* Set up initial state. */ + mutex_lock(&lock); + num_threads = num_online_cpus(); + active_cpus = cpus; active.fn = fn; active.data = data; active.fnret = 0; idle.fn = chill; idle.data = NULL; - /* This could be too big for stack on large machines. */ - threads = kcalloc(NR_CPUS, sizeof(threads[0]), GFP_KERNEL); - if (!threads) - return -ENOMEM; - - /* Set up initial state. */ - mutex_lock(&lock); - init_completion(&finished); - num_threads = num_online_cpus(); set_state(STOPMACHINE_PREPARE); - for_each_online_cpu(i) { - struct stop_machine_data *smdata = &idle; - struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 }; - - if (!cpus) { - if (i == first_cpu(cpu_online_map)) - smdata = &active; - } else { - if (cpu_isset(i, *cpus)) - smdata = &active; - } - - threads[i] = kthread_create((void *)stop_cpu, smdata, "kstop%u", - i); - if (IS_ERR(threads[i])) { - err = PTR_ERR(threads[i]); - threads[i] = NULL; - goto kill_threads; - } - - /* Place it onto correct cpu. */ - kthread_bind(threads[i], i); - - /* Make it highest prio. */ - if (sched_setscheduler_nocheck(threads[i], SCHED_FIFO, ¶m)) - BUG(); - } - - /* We've created all the threads. Wake them all: hold this CPU so one + /* Schedule the stop_cpu work on all cpus: hold this CPU so one * doesn't hit this CPU until we're ready. */ get_cpu(); - for_each_online_cpu(i) - wake_up_process(threads[i]); - + for_each_online_cpu(i) { + sm_work = percpu_ptr(stop_machine_work, i); + INIT_WORK(sm_work, stop_cpu); + queue_work_on(i, stop_machine_wq, sm_work); + } /* This will release the thread on our CPU. */ put_cpu(); - wait_for_completion(&finished); + flush_workqueue(stop_machine_wq); mutex_unlock(&lock); - - kfree(threads); - return active.fnret; - -kill_threads: - for_each_online_cpu(i) - if (threads[i]) - kthread_stop(threads[i]); - mutex_unlock(&lock); - - kfree(threads); - return err; } int stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus) @@ -187,3 +153,11 @@ int stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus) return ret; } EXPORT_SYMBOL_GPL(stop_machine); + +static int __init stop_machine_init(void) +{ + stop_machine_wq = create_rt_workqueue("kstop"); + stop_machine_work = alloc_percpu(struct work_struct); + return 0; +} +early_initcall(stop_machine_init); diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 714afad..f928f2a 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -62,6 +62,7 @@ struct workqueue_struct { const char *name; int singlethread; int freezeable; /* Freeze threads during suspend */ + int rt; #ifdef CONFIG_LOCKDEP struct lockdep_map lockdep_map; #endif @@ -766,6 +767,7 @@ init_cpu_workqueue(struct workqueue_struct *wq, int cpu) static int create_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu) { + struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 }; struct workqueue_struct *wq = cwq->wq; const char *fmt = is_single_threaded(wq) ? "%s" : "%s/%d"; struct task_struct *p; @@ -781,7 +783,8 @@ static int create_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu) */ if (IS_ERR(p)) return PTR_ERR(p); - + if (cwq->wq->rt) + sched_setscheduler_nocheck(p, SCHED_FIFO, ¶m); cwq->thread = p; return 0; @@ -801,6 +804,7 @@ static void start_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu) struct workqueue_struct *__create_workqueue_key(const char *name, int singlethread, int freezeable, + int rt, struct lock_class_key *key, const char *lock_name) { @@ -822,6 +826,7 @@ struct workqueue_struct *__create_workqueue_key(const char *name, lockdep_init_map(&wq->lockdep_map, lock_name, key, 0); wq->singlethread = singlethread; wq->freezeable = freezeable; + wq->rt = rt; INIT_LIST_HEAD(&wq->list); if (singlethread) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/