From da39ba5e1d65e997a98f6eb93ba6e6eb505f6e3c Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 22 Jul 2008 19:24:25 -0500 Subject: [PATCH 01/12] module: don't use stop_machine for waiting rmmod rmmod has a little-used "-w" option, meaning that instead of failing if the module is in use, it should block until the module becomes unused. In this case, we don't need to use stop_machine: Max Krasnyansky indicated that would be useful for SystemTap which loads/unloads new modules frequently. Cc: Max Krasnyansky Signed-off-by: Rusty Russell --- kernel/module.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/kernel/module.c b/kernel/module.c index 5f80478b746d..705e1d5d516c 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -639,8 +639,8 @@ static int __try_stop_module(void *_sref) { struct stopref *sref = _sref; - /* If it's not unused, quit unless we are told to block. */ - if ((sref->flags & O_NONBLOCK) && module_refcount(sref->mod) != 0) { + /* If it's not unused, quit unless we're forcing. */ + if (module_refcount(sref->mod) != 0) { if (!(*sref->forced = try_force_unload(sref->flags))) return -EWOULDBLOCK; } @@ -652,9 +652,16 @@ static int __try_stop_module(void *_sref) static int try_stop_module(struct module *mod, int flags, int *forced) { - struct stopref sref = { mod, flags, forced }; + if (flags & O_NONBLOCK) { + struct stopref sref = { mod, flags, forced }; - return stop_machine_run(__try_stop_module, &sref, NR_CPUS); + return stop_machine_run(__try_stop_module, &sref, NR_CPUS); + } else { + /* We don't need to stop the machine for this. */ + mod->state = MODULE_STATE_GOING; + synchronize_sched(); + return 0; + } } unsigned int module_refcount(struct module *mod) From dafd0940c96fec67974a88ed8e6b8ba3160394cd Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 22 Jul 2008 19:24:25 -0500 Subject: [PATCH 02/12] module: generic each_symbol iterator function Introduce an each_symbol() iterator to avoid duplicating the knowledge about the 5 different sections containing symbols. Currently only used by find_symbol(), but will be used by symbol_put_addr() too. (Includes NULL ptr deref fix by Jiri Kosina ) Signed-off-by: Rusty Russell Cc: Jiri Kosina --- kernel/module.c | 254 ++++++++++++++++++++++++++---------------------- 1 file changed, 139 insertions(+), 115 deletions(-) diff --git a/kernel/module.c b/kernel/module.c index 705e1d5d516c..c51c089c666e 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -152,28 +152,127 @@ extern const unsigned long __start___kcrctab_unused_gpl[]; #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL) #endif -/* lookup symbol in given range of kernel_symbols */ -static const struct kernel_symbol *lookup_symbol(const char *name, - const struct kernel_symbol *start, - const struct kernel_symbol *stop) +struct symsearch { + const struct kernel_symbol *start, *stop; + const unsigned long *crcs; + enum { + NOT_GPL_ONLY, + GPL_ONLY, + WILL_BE_GPL_ONLY, + } licence; + bool unused; +}; + +static bool each_symbol_in_section(const struct symsearch *arr, + unsigned int arrsize, + struct module *owner, + bool (*fn)(const struct symsearch *syms, + struct module *owner, + unsigned int symnum, void *data), + void *data) { - const struct kernel_symbol *ks = start; - for (; ks < stop; ks++) - if (strcmp(ks->name, name) == 0) - return ks; - return NULL; + unsigned int i, j; + + for (j = 0; j < arrsize; j++) { + for (i = 0; i < arr[j].stop - arr[j].start; i++) + if (fn(&arr[j], owner, i, data)) + return true; + } + + return false; } -static bool always_ok(bool gplok, bool warn, const char *name) +/* Returns true as soon as fn returns true, otherwise false. */ +static bool each_symbol(bool (*fn)(const struct symsearch *arr, + struct module *owner, + unsigned int symnum, void *data), + void *data) { - return true; + struct module *mod; + const struct symsearch arr[] = { + { __start___ksymtab, __stop___ksymtab, __start___kcrctab, + NOT_GPL_ONLY, false }, + { __start___ksymtab_gpl, __stop___ksymtab_gpl, + __start___kcrctab_gpl, + GPL_ONLY, false }, + { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future, + __start___kcrctab_gpl_future, + WILL_BE_GPL_ONLY, false }, + { __start___ksymtab_unused, __stop___ksymtab_unused, + __start___kcrctab_unused, + NOT_GPL_ONLY, true }, + { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl, + __start___kcrctab_unused_gpl, + GPL_ONLY, true }, + }; + + if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data)) + return true; + + list_for_each_entry(mod, &modules, list) { + struct symsearch arr[] = { + { mod->syms, mod->syms + mod->num_syms, mod->crcs, + NOT_GPL_ONLY, false }, + { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms, + mod->gpl_crcs, + GPL_ONLY, false }, + { mod->gpl_future_syms, + mod->gpl_future_syms + mod->num_gpl_future_syms, + mod->gpl_future_crcs, + WILL_BE_GPL_ONLY, false }, + { mod->unused_syms, + mod->unused_syms + mod->num_unused_syms, + mod->unused_crcs, + NOT_GPL_ONLY, true }, + { mod->unused_gpl_syms, + mod->unused_gpl_syms + mod->num_unused_gpl_syms, + mod->unused_gpl_crcs, + GPL_ONLY, true }, + }; + + if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data)) + return true; + } + return false; } -static bool printk_unused_warning(bool gplok, bool warn, const char *name) +struct find_symbol_arg { + /* Input */ + const char *name; + bool gplok; + bool warn; + + /* Output */ + struct module *owner; + const unsigned long *crc; + unsigned long value; +}; + +static bool find_symbol_in_section(const struct symsearch *syms, + struct module *owner, + unsigned int symnum, void *data) { - if (warn) { + struct find_symbol_arg *fsa = data; + + if (strcmp(syms->start[symnum].name, fsa->name) != 0) + return false; + + if (!fsa->gplok) { + if (syms->licence == GPL_ONLY) + return false; + if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) { + printk(KERN_WARNING "Symbol %s is being used " + "by a non-GPL module, which will not " + "be allowed in the future\n", fsa->name); + printk(KERN_WARNING "Please see the file " + "Documentation/feature-removal-schedule.txt " + "in the kernel source tree for more details.\n"); + } + } + + if (syms->unused && fsa->warn) { printk(KERN_WARNING "Symbol %s is marked as UNUSED, " - "however this module is using it.\n", name); + "however this module is using it.\n", fsa->name); printk(KERN_WARNING "This symbol will go away in the future.\n"); printk(KERN_WARNING @@ -182,64 +281,13 @@ static bool printk_unused_warning(bool gplok, bool warn, const char *name) "mailinglist together with submitting your code for " "inclusion.\n"); } + + fsa->owner = owner; + fsa->crc = symversion(syms->crcs, symnum); + fsa->value = syms->start[symnum].value; return true; } -static bool gpl_only_unused_warning(bool gplok, bool warn, const char *name) -{ - if (!gplok) - return false; - return printk_unused_warning(gplok, warn, name); -} - -static bool gpl_only(bool gplok, bool warn, const char *name) -{ - return gplok; -} - -static bool warn_if_not_gpl(bool gplok, bool warn, const char *name) -{ - if (!gplok && warn) { - printk(KERN_WARNING "Symbol %s is being used " - "by a non-GPL module, which will not " - "be allowed in the future\n", name); - printk(KERN_WARNING "Please see the file " - "Documentation/feature-removal-schedule.txt " - "in the kernel source tree for more details.\n"); - } - return true; -} - -struct symsearch { - const struct kernel_symbol *start, *stop; - const unsigned long *crcs; - bool (*check)(bool gplok, bool warn, const char *name); -}; - -/* Look through this array of symbol tables for a symbol match which - * passes the check function. */ -static const struct kernel_symbol *search_symarrays(const struct symsearch *arr, - unsigned int num, - const char *name, - bool gplok, - bool warn, - const unsigned long **crc) -{ - unsigned int i; - const struct kernel_symbol *ks; - - for (i = 0; i < num; i++) { - ks = lookup_symbol(name, arr[i].start, arr[i].stop); - if (!ks || !arr[i].check(gplok, warn, name)) - continue; - - if (crc) - *crc = symversion(arr[i].crcs, ks - arr[i].start); - return ks; - } - return NULL; -} - /* Find a symbol, return value, (optional) crc and (optional) module * which owns it */ static unsigned long find_symbol(const char *name, @@ -248,60 +296,36 @@ static unsigned long find_symbol(const char *name, bool gplok, bool warn) { - struct module *mod; - const struct kernel_symbol *ks; - const struct symsearch arr[] = { - { __start___ksymtab, __stop___ksymtab, __start___kcrctab, - always_ok }, - { __start___ksymtab_gpl, __stop___ksymtab_gpl, - __start___kcrctab_gpl, gpl_only }, - { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future, - __start___kcrctab_gpl_future, warn_if_not_gpl }, - { __start___ksymtab_unused, __stop___ksymtab_unused, - __start___kcrctab_unused, printk_unused_warning }, - { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl, - __start___kcrctab_unused_gpl, gpl_only_unused_warning }, - }; + struct find_symbol_arg fsa; - /* Core kernel first. */ - ks = search_symarrays(arr, ARRAY_SIZE(arr), name, gplok, warn, crc); - if (ks) { + fsa.name = name; + fsa.gplok = gplok; + fsa.warn = warn; + + if (each_symbol(find_symbol_in_section, &fsa)) { if (owner) - *owner = NULL; - return ks->value; - } - - /* Now try modules. */ - list_for_each_entry(mod, &modules, list) { - struct symsearch arr[] = { - { mod->syms, mod->syms + mod->num_syms, mod->crcs, - always_ok }, - { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms, - mod->gpl_crcs, gpl_only }, - { mod->gpl_future_syms, - mod->gpl_future_syms + mod->num_gpl_future_syms, - mod->gpl_future_crcs, warn_if_not_gpl }, - { mod->unused_syms, - mod->unused_syms + mod->num_unused_syms, - mod->unused_crcs, printk_unused_warning }, - { mod->unused_gpl_syms, - mod->unused_gpl_syms + mod->num_unused_gpl_syms, - mod->unused_gpl_crcs, gpl_only_unused_warning }, - }; - - ks = search_symarrays(arr, ARRAY_SIZE(arr), - name, gplok, warn, crc); - if (ks) { - if (owner) - *owner = mod; - return ks->value; - } + *owner = fsa.owner; + if (crc) + *crc = fsa.crc; + return fsa.value; } DEBUGP("Failed to find symbol %s\n", name); return -ENOENT; } +/* lookup symbol in given range of kernel_symbols */ +static const struct kernel_symbol *lookup_symbol(const char *name, + const struct kernel_symbol *start, + const struct kernel_symbol *stop) +{ + const struct kernel_symbol *ks = start; + for (; ks < stop; ks++) + if (strcmp(ks->name, name) == 0) + return ks; + return NULL; +} + /* Search for module by name: must hold module_mutex. */ static struct module *find_module(const char *name) { From af5406895a05720a879dc33e2f4878fa503e81b3 Mon Sep 17 00:00:00 2001 From: Richard Kennedy Date: Tue, 22 Jul 2008 19:24:26 -0500 Subject: [PATCH 03/12] module: reorder struct module to save space on 64 bit builds reorder struct module to save space on 64 bit builds. saves 1 cacheline_size (128 on default x86_64 & 64 on AMD Opteron/athlon) when CONFIG_MODULE_UNLOAD=y. Signed-off-by: Richard Kennedy Signed-off-by: Rusty Russell --- include/linux/module.h | 42 ++++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 20 deletions(-) diff --git a/include/linux/module.h b/include/linux/module.h index 3e03b1acbc94..63f0eb69e214 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -249,27 +249,28 @@ struct module /* Exported symbols */ const struct kernel_symbol *syms; - unsigned int num_syms; const unsigned long *crcs; + unsigned int num_syms; /* GPL-only exported symbols. */ - const struct kernel_symbol *gpl_syms; unsigned int num_gpl_syms; + const struct kernel_symbol *gpl_syms; const unsigned long *gpl_crcs; /* unused exported symbols. */ const struct kernel_symbol *unused_syms; - unsigned int num_unused_syms; const unsigned long *unused_crcs; + unsigned int num_unused_syms; + /* GPL-only, unused exported symbols. */ - const struct kernel_symbol *unused_gpl_syms; unsigned int num_unused_gpl_syms; + const struct kernel_symbol *unused_gpl_syms; const unsigned long *unused_gpl_crcs; /* symbols that will be GPL-only in the near future. */ const struct kernel_symbol *gpl_future_syms; - unsigned int num_gpl_future_syms; const unsigned long *gpl_future_crcs; + unsigned int num_gpl_future_syms; /* Exception table */ unsigned int num_exentries; @@ -300,23 +301,9 @@ struct module #ifdef CONFIG_GENERIC_BUG /* Support for BUG */ + unsigned num_bugs; struct list_head bug_list; struct bug_entry *bug_table; - unsigned num_bugs; -#endif - -#ifdef CONFIG_MODULE_UNLOAD - /* Reference counts */ - struct module_ref ref[NR_CPUS]; - - /* What modules depend on me? */ - struct list_head modules_which_use_me; - - /* Who is waiting for us to be unloaded */ - struct task_struct *waiter; - - /* Destruction function. */ - void (*exit)(void); #endif #ifdef CONFIG_KALLSYMS @@ -342,6 +329,21 @@ struct module struct marker *markers; unsigned int num_markers; #endif + +#ifdef CONFIG_MODULE_UNLOAD + /* What modules depend on me? */ + struct list_head modules_which_use_me; + + /* Who is waiting for us to be unloaded */ + struct task_struct *waiter; + + /* Destruction function. */ + void (*exit)(void); + + /* Reference counts */ + struct module_ref ref[NR_CPUS]; +#endif + }; #ifndef MODULE_ARCH_INIT #define MODULE_ARCH_INIT {} From f7f5b67557eac1131ba6532522e3c50eced34238 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Tue, 22 Jul 2008 19:24:26 -0500 Subject: [PATCH 04/12] Shrink struct module: CONFIG_UNUSED_SYMBOLS ifdefs module.c and module.h conatains code for finding exported symbols which are declared with EXPORT_UNUSED_SYMBOL, and this code is compiled in even if CONFIG_UNUSED_SYMBOLS is not set and thus there can be no EXPORT_UNUSED_SYMBOLs in modules anyway (because EXPORT_UNUSED_SYMBOL(x) are compiled out to nothing then). This patch adds required #ifdefs. Signed-off-by: Denys Vlasenko Signed-off-by: Rusty Russell --- include/linux/module.h | 2 ++ init/Kconfig | 4 ++-- kernel/module.c | 49 +++++++++++++++++++++++++++++------------- 3 files changed, 38 insertions(+), 17 deletions(-) diff --git a/include/linux/module.h b/include/linux/module.h index 63f0eb69e214..a860a2c1f379 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -257,6 +257,7 @@ struct module const struct kernel_symbol *gpl_syms; const unsigned long *gpl_crcs; +#ifdef CONFIG_UNUSED_SYMBOLS /* unused exported symbols. */ const struct kernel_symbol *unused_syms; const unsigned long *unused_crcs; @@ -266,6 +267,7 @@ struct module unsigned int num_unused_gpl_syms; const struct kernel_symbol *unused_gpl_syms; const unsigned long *unused_gpl_crcs; +#endif /* symbols that will be GPL-only in the near future. */ const struct kernel_symbol *gpl_future_syms; diff --git a/init/Kconfig b/init/Kconfig index 6199d1120900..c8578f9ee31d 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -856,8 +856,8 @@ config MODULE_UNLOAD help Without this option you will not be able to unload any modules (note that some modules may not be unloadable - anyway), which makes your kernel slightly smaller and - simpler. If unsure, say Y. + anyway), which makes your kernel smaller, faster + and simpler. If unsure, say Y. config MODULE_FORCE_UNLOAD bool "Forced module unloading" diff --git a/kernel/module.c b/kernel/module.c index c51c089c666e..ea9580521eb1 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -134,17 +134,19 @@ extern const struct kernel_symbol __start___ksymtab_gpl[]; extern const struct kernel_symbol __stop___ksymtab_gpl[]; extern const struct kernel_symbol __start___ksymtab_gpl_future[]; extern const struct kernel_symbol __stop___ksymtab_gpl_future[]; -extern const struct kernel_symbol __start___ksymtab_unused[]; -extern const struct kernel_symbol __stop___ksymtab_unused[]; -extern const struct kernel_symbol __start___ksymtab_unused_gpl[]; -extern const struct kernel_symbol __stop___ksymtab_unused_gpl[]; extern const struct kernel_symbol __start___ksymtab_gpl_future[]; extern const struct kernel_symbol __stop___ksymtab_gpl_future[]; extern const unsigned long __start___kcrctab[]; extern const unsigned long __start___kcrctab_gpl[]; extern const unsigned long __start___kcrctab_gpl_future[]; +#ifdef CONFIG_UNUSED_SYMBOLS +extern const struct kernel_symbol __start___ksymtab_unused[]; +extern const struct kernel_symbol __stop___ksymtab_unused[]; +extern const struct kernel_symbol __start___ksymtab_unused_gpl[]; +extern const struct kernel_symbol __stop___ksymtab_unused_gpl[]; extern const unsigned long __start___kcrctab_unused[]; extern const unsigned long __start___kcrctab_unused_gpl[]; +#endif #ifndef CONFIG_MODVERSIONS #define symversion(base, idx) NULL @@ -198,12 +200,14 @@ static bool each_symbol(bool (*fn)(const struct symsearch *arr, { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future, __start___kcrctab_gpl_future, WILL_BE_GPL_ONLY, false }, +#ifdef CONFIG_UNUSED_SYMBOLS { __start___ksymtab_unused, __stop___ksymtab_unused, __start___kcrctab_unused, NOT_GPL_ONLY, true }, { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl, __start___kcrctab_unused_gpl, GPL_ONLY, true }, +#endif }; if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data)) @@ -220,6 +224,7 @@ static bool each_symbol(bool (*fn)(const struct symsearch *arr, mod->gpl_future_syms + mod->num_gpl_future_syms, mod->gpl_future_crcs, WILL_BE_GPL_ONLY, false }, +#ifdef CONFIG_UNUSED_SYMBOLS { mod->unused_syms, mod->unused_syms + mod->num_unused_syms, mod->unused_crcs, @@ -228,6 +233,7 @@ static bool each_symbol(bool (*fn)(const struct symsearch *arr, mod->unused_gpl_syms + mod->num_unused_gpl_syms, mod->unused_gpl_crcs, GPL_ONLY, true }, +#endif }; if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data)) @@ -270,6 +276,7 @@ static bool find_symbol_in_section(const struct symsearch *syms, } } +#ifdef CONFIG_UNUSED_SYMBOLS if (syms->unused && fsa->warn) { printk(KERN_WARNING "Symbol %s is marked as UNUSED, " "however this module is using it.\n", fsa->name); @@ -281,6 +288,7 @@ static bool find_symbol_in_section(const struct symsearch *syms, "mailinglist together with submitting your code for " "inclusion.\n"); } +#endif fsa->owner = owner; fsa->crc = symversion(syms->crcs, symnum); @@ -1476,8 +1484,10 @@ static int verify_export_symbols(struct module *mod) { mod->syms, mod->num_syms }, { mod->gpl_syms, mod->num_gpl_syms }, { mod->gpl_future_syms, mod->num_gpl_future_syms }, +#ifdef CONFIG_UNUSED_SYMBOLS { mod->unused_syms, mod->num_unused_syms }, { mod->unused_gpl_syms, mod->num_unused_gpl_syms }, +#endif }; for (i = 0; i < ARRAY_SIZE(arr); i++) { @@ -1795,10 +1805,12 @@ static struct module *load_module(void __user *umod, unsigned int gplfutureindex; unsigned int gplfuturecrcindex; 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; struct module *mod; @@ -1881,13 +1893,15 @@ static struct module *load_module(void __user *umod, exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab"); gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl"); gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future"); - unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused"); - unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl"); 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"); @@ -2049,14 +2063,15 @@ static struct module *load_module(void __user *umod, mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr; mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size / sizeof(*mod->gpl_future_syms); - 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->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr; if (gplfuturecrcindex) mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr; +#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; @@ -2064,13 +2079,17 @@ static struct module *load_module(void __user *umod, if (unusedgplcrcindex) mod->unused_gpl_crcs = (void *)sechdrs[unusedgplcrcindex].sh_addr; +#endif #ifdef CONFIG_MODVERSIONS - if ((mod->num_syms && !crcindex) || - (mod->num_gpl_syms && !gplcrcindex) || - (mod->num_gpl_future_syms && !gplfuturecrcindex) || - (mod->num_unused_syms && !unusedcrcindex) || - (mod->num_unused_gpl_syms && !unusedgplcrcindex)) { + if ((mod->num_syms && !crcindex) + || (mod->num_gpl_syms && !gplcrcindex) + || (mod->num_gpl_future_syms && !gplfuturecrcindex) +#ifdef CONFIG_UNUSED_SYMBOLS + || (mod->num_unused_syms && !unusedcrcindex) + || (mod->num_unused_gpl_syms && !unusedgplcrcindex) +#endif + ) { printk(KERN_WARNING "%s: No versions for exported symbols.\n", mod->name); err = try_to_force_load(mod, "nocrc"); if (err) From 2f0f2a334bc38b61a9afca951185cd3844ee709d Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Tue, 22 Jul 2008 19:24:27 -0500 Subject: [PATCH 05/12] module: turn longs into ints for module sizes This shrinks module.o and each *.ko file. And finally, structure members which hold length of module code (four such members there) and count of symbols are converted from longs to ints. We cannot possibly have a module where 32 bits won't be enough to hold such counts. For one, module loading checks module size for sanity before loading, so such insanely big module will fail that test first. Signed-off-by: Denys Vlasenko Signed-off-by: Rusty Russell --- include/linux/module.h | 6 +++--- kernel/module.c | 4 ++-- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/include/linux/module.h b/include/linux/module.h index a860a2c1f379..fce15ebd0e1c 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -288,10 +288,10 @@ struct module void *module_core; /* Here are the sizes of the init and core sections */ - unsigned long init_size, core_size; + unsigned int init_size, core_size; /* The size of the executable code in each section. */ - unsigned long init_text_size, core_text_size; + unsigned int init_text_size, core_text_size; /* The handle returned from unwind_add_table. */ void *unwind_info; @@ -311,7 +311,7 @@ struct module #ifdef CONFIG_KALLSYMS /* We keep the symbol and string tables for kallsyms. */ Elf_Sym *symtab; - unsigned long num_symtab; + unsigned int num_symtab; char *strtab; /* Section attributes */ diff --git a/kernel/module.c b/kernel/module.c index ea9580521eb1..5c7eb0695b3c 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1567,7 +1567,7 @@ static int simplify_symbols(Elf_Shdr *sechdrs, } /* Update size with this section: return offset. */ -static long get_offset(unsigned long *size, Elf_Shdr *sechdr) +static long get_offset(unsigned int *size, Elf_Shdr *sechdr) { long ret; @@ -2562,7 +2562,7 @@ static int m_show(struct seq_file *m, void *p) struct module *mod = list_entry(p, struct module, list); char buf[8]; - seq_printf(m, "%s %lu", + seq_printf(m, "%s %u", mod->name, mod->init_size + mod->core_size); print_unload_info(m, mod); From 3a642e99babe0617febb6f402e1e063479f489db Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 22 Jul 2008 19:24:28 -0500 Subject: [PATCH 06/12] modules: Take a shortcut for checking if an address is in a module This patch keeps track of the boundaries of module allocation, in order to speed up module_text_address(). Inspired by Arjan's version, which required arch-specific defines: Various pieces of the kernel (lockdep, latencytop, etc) tend to store backtraces, sometimes at a relatively high frequency. In itself this isn't a big performance deal (after all you're using diagnostics features), but there have been some complaints from people who have over 100 modules loaded that this is a tad too slow. This is due to the new backtracer code which looks at every slot on the stack to see if it's a kernel/module text address, so that's 1024 slots. 1024 times 100 modules... that's a lot of list walking. Signed-off-by: Rusty Russell --- kernel/module.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/kernel/module.c b/kernel/module.c index 5c7eb0695b3c..d8b5605132a0 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -70,6 +70,9 @@ static DECLARE_WAIT_QUEUE_HEAD(module_wq); static BLOCKING_NOTIFIER_HEAD(module_notify_list); +/* Bounds of module allocation, for speeding __module_text_address */ +static unsigned long module_addr_min = -1UL, module_addr_max = 0; + int register_module_notifier(struct notifier_block * nb) { return blocking_notifier_chain_register(&module_notify_list, nb); @@ -1779,6 +1782,20 @@ static inline void add_kallsyms(struct module *mod, } #endif /* CONFIG_KALLSYMS */ +static void *module_alloc_update_bounds(unsigned long size) +{ + void *ret = module_alloc(size); + + if (ret) { + /* Update module bounds. */ + if ((unsigned long)ret < module_addr_min) + module_addr_min = (unsigned long)ret; + if ((unsigned long)ret + size > module_addr_max) + module_addr_max = (unsigned long)ret + size; + } + return ret; +} + /* Allocate and load the module: note that size of section 0 is always zero, and we rely on this for optional sections. */ static struct module *load_module(void __user *umod, @@ -1980,7 +1997,7 @@ static struct module *load_module(void __user *umod, layout_sections(mod, hdr, sechdrs, secstrings); /* Do the allocs. */ - ptr = module_alloc(mod->core_size); + ptr = module_alloc_update_bounds(mod->core_size); if (!ptr) { err = -ENOMEM; goto free_percpu; @@ -1988,7 +2005,7 @@ static struct module *load_module(void __user *umod, memset(ptr, 0, mod->core_size); mod->module_core = ptr; - ptr = module_alloc(mod->init_size); + ptr = module_alloc_update_bounds(mod->init_size); if (!ptr && mod->init_size) { err = -ENOMEM; goto free_core; @@ -2645,6 +2662,9 @@ struct module *__module_text_address(unsigned long addr) { struct module *mod; + if (addr < module_addr_min || addr > module_addr_max) + return NULL; + list_for_each_entry(mod, &modules, list) if (within(addr, mod->module_init, mod->init_text_size) || within(addr, mod->module_core, mod->core_text_size)) From baabaae98125fbd1a8dc258aa95333c01cd9e206 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 8 Jul 2008 19:00:16 +0200 Subject: [PATCH 07/12] make CONFIG_KMOD invisible ... as preparation for removing it completely, make it an invisible bool defaulting to yes. Signed-off-by: Johannes Berg Signed-off-by: Rusty Russell --- init/Kconfig | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/init/Kconfig b/init/Kconfig index c8578f9ee31d..a50bdfed2df7 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -893,16 +893,11 @@ config MODULE_SRCVERSION_ALL will be created for all modules. If unsure, say N. config KMOD - bool "Automatic kernel module loading" + def_bool y depends on MODULES help - Normally when you have selected some parts of the kernel to - be created as kernel modules, you must load them (using the - "modprobe" command) before you can use them. If you say Y - here, some parts of the kernel will be able to load modules - automatically: when a part of the kernel needs a module, it - runs modprobe with the appropriate arguments, thereby - loading the module if it is available. If unsure, say Y. + This is being removed soon. These days, CONFIG_MODULES + implies CONFIG_KMOD, so use that instead. config STOP_MACHINE bool From a81792f668c20540c336af4242ba1400763eb14f Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 8 Jul 2008 19:00:25 +0200 Subject: [PATCH 08/12] remove mention of CONFIG_KMOD from documentation Also includes a few Kconfig files (xtensa, blackfin) Signed-off-by: Johannes Berg Cc: Michael Kerrisk Cc: linux-doc@vger.kernel.org Signed-off-by: Rusty Russell Acked-by: Randy Dunlap --- Documentation/filesystems/bfs.txt | 10 +++++----- .../sound/alsa/DocBook/alsa-driver-api.tmpl | 2 +- Documentation/telephony/ixj.txt | 13 +++---------- Documentation/video4linux/w9968cf.txt | 3 --- arch/blackfin/Kconfig | 4 ++-- arch/xtensa/Kconfig | 4 ++-- 6 files changed, 13 insertions(+), 23 deletions(-) diff --git a/Documentation/filesystems/bfs.txt b/Documentation/filesystems/bfs.txt index ea825e178e79..78043d5a8fc3 100644 --- a/Documentation/filesystems/bfs.txt +++ b/Documentation/filesystems/bfs.txt @@ -26,11 +26,11 @@ You can simplify mounting by just typing: this will allocate the first available loopback device (and load loop.o kernel module if necessary) automatically. If the loopback driver is not -loaded automatically, make sure that your kernel is compiled with kmod -support (CONFIG_KMOD) enabled. Beware that umount will not -deallocate /dev/loopN device if /etc/mtab file on your system is a -symbolic link to /proc/mounts. You will need to do it manually using -"-d" switch of losetup(8). Read losetup(8) manpage for more info. +loaded automatically, make sure that you have compiled the module and +that modprobe is functioning. Beware that umount will not deallocate +/dev/loopN device if /etc/mtab file on your system is a symbolic link to +/proc/mounts. You will need to do it manually using "-d" switch of +losetup(8). Read losetup(8) manpage for more info. To create the BFS image under UnixWare you need to find out first which slice contains it. The command prtvtoc(1M) is your friend: diff --git a/Documentation/sound/alsa/DocBook/alsa-driver-api.tmpl b/Documentation/sound/alsa/DocBook/alsa-driver-api.tmpl index c4d2e3507af9..9d644f7e241e 100644 --- a/Documentation/sound/alsa/DocBook/alsa-driver-api.tmpl +++ b/Documentation/sound/alsa/DocBook/alsa-driver-api.tmpl @@ -42,7 +42,7 @@ Device Components !Esound/core/device.c - KMOD and Device File Entries + Module requests and Device File Entries !Esound/core/sound.c Memory Management Helpers diff --git a/Documentation/telephony/ixj.txt b/Documentation/telephony/ixj.txt index 621024fd3a18..44d124005bad 100644 --- a/Documentation/telephony/ixj.txt +++ b/Documentation/telephony/ixj.txt @@ -305,21 +305,14 @@ driver, like this: which will result in the needed drivers getting loaded automatically. - g. if you are planning on using kerneld to automatically load the -module for you, then you need to edit /etc/conf.modules and add the + g. if you are planning on having the kernel automatically request +the module for you, then you need to edit /etc/conf.modules and add the following lines: options ixj dspio=0x340 xio=0x330 ixjdebug=0 If you do this, then when you execute an application that uses the -module kerneld will load the module for you. Note that to do this, -you need to have your kernel set to support kerneld. You can check -for this by looking at /usr/src/linux/.config and you should see this: - - # Loadable module support - # - - CONFIG_KMOD=y +module the kernel will request that it is loaded. h. if you want non-root users to be able to read and write to the ixj devices (this is a good idea!) you should do the following: diff --git a/Documentation/video4linux/w9968cf.txt b/Documentation/video4linux/w9968cf.txt index e0bba8393c77..05138e8aea07 100644 --- a/Documentation/video4linux/w9968cf.txt +++ b/Documentation/video4linux/w9968cf.txt @@ -193,9 +193,6 @@ Description: Automatic 'ovcamchip' module loading: 0 disabled, 1 enabled. loads that module automatically. This action is performed as once soon as the 'w9968cf' module is loaded into memory. Default: 1 -Note: The kernel must be compiled with the CONFIG_KMOD option - enabled for the 'ovcamchip' module to be loaded and for - this parameter to be present. ------------------------------------------------------------------------------- Name: simcams Type: int diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig index b87634e75f20..b83b8ef84e91 100644 --- a/arch/blackfin/Kconfig +++ b/arch/blackfin/Kconfig @@ -873,8 +873,8 @@ config HOTPLUG plugged into slots found on all modern laptop computers. Another example, used on modern desktops as well as laptops, is USB. - Enable HOTPLUG and KMOD, and build a modular kernel. Get agent - software (at ) and install it. + Enable HOTPLUG and build a modular kernel. Get agent software + (from ) and install it. Then your kernel will automatically call out to a user mode "policy agent" (/sbin/hotplug) to load modules and set up software needed to use devices as you hotplug them. diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig index 9fc8551a1cf6..02e417d3d8e9 100644 --- a/arch/xtensa/Kconfig +++ b/arch/xtensa/Kconfig @@ -194,8 +194,8 @@ config HOTPLUG plugged into slots found on all modern laptop computers. Another example, used on modern desktops as well as laptops, is USB. - Enable HOTPLUG and KMOD, and build a modular kernel. Get agent - software (at ) and install it. + Enable HOTPLUG and build a modular kernel. Get agent software + (from ) and install it. Then your kernel will automatically call out to a user mode "policy agent" (/sbin/hotplug) to load modules and set up software needed to use devices as you hotplug them. From df648c9fbebb4de50e7a6e76cc253c7cb0421f9b Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 8 Jul 2008 19:00:18 +0200 Subject: [PATCH 09/12] rework try_then_request_module to do less in non-modular kernels This reworks try_then_request_module to only invoke the "lookup" function "x" once when the kernel is not modular. Signed-off-by: Johannes Berg Signed-off-by: Rusty Russell --- include/linux/kmod.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/kmod.h b/include/linux/kmod.h index 5dc13848891b..9bdb28d6660f 100644 --- a/include/linux/kmod.h +++ b/include/linux/kmod.h @@ -29,11 +29,12 @@ /* modprobe exit status on success, -ve on error. Return value * usually useless though. */ extern int request_module(const char * name, ...) __attribute__ ((format (printf, 1, 2))); +#define try_then_request_module(x, mod...) ((x) ?: (request_module(mod), (x))) #else static inline int request_module(const char * name, ...) { return -ENOSYS; } +#define try_then_request_module(x, mod...) (x) #endif -#define try_then_request_module(x, mod...) ((x) ?: (request_module(mod), (x))) struct key; struct file; From 184b6c7682e484032e3f845eef5db26e72681d6f Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 8 Jul 2008 19:00:20 +0200 Subject: [PATCH 10/12] remove CONFIG_KMOD from sparc64 One place is just a comment, the other a conditional, unused inclusion of linux/kmod.h. Signed-off-by: Johannes Berg Cc: David S. Miller Signed-off-by: Rusty Russell --- arch/sparc64/kernel/process.c | 6 +++--- arch/sparc64/kernel/traps.c | 3 --- 2 files changed, 3 insertions(+), 6 deletions(-) diff --git a/arch/sparc64/kernel/process.c b/arch/sparc64/kernel/process.c index c1f1ff29e979..31ea752d307b 100644 --- a/arch/sparc64/kernel/process.c +++ b/arch/sparc64/kernel/process.c @@ -683,9 +683,9 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, ((unsigned long) child_sf) - STACK_BIAS; /* Special case, if we are spawning a kernel thread from - * a userspace task (via KMOD, NFS, or similar) we must - * disable performance counters in the child because the - * address space and protection realm are changing. + * a userspace task (usermode helper, NFS or similar), we + * must disable performance counters in the child because + * the address space and protection realm are changing. */ if (t->flags & _TIF_PERFCTR) { t->user_cntd0 = t->user_cntd1 = NULL; diff --git a/arch/sparc64/kernel/traps.c b/arch/sparc64/kernel/traps.c index 0aa819c29dbc..bd30ecba5630 100644 --- a/arch/sparc64/kernel/traps.c +++ b/arch/sparc64/kernel/traps.c @@ -36,9 +36,6 @@ #include #include #include -#ifdef CONFIG_KMOD -#include -#endif #include #include "entry.h" From a00caa1fa954c734f4214a074727a329a9ba6568 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 8 Jul 2008 19:00:24 +0200 Subject: [PATCH 11/12] remove CONFIG_KMOD from lib textsearch algorithms can be loaded, make the code depend on CONFIG_MODULES instead of CONFIG_KMOD. Signed-off-by: Johannes Berg Signed-off-by: Rusty Russell --- lib/textsearch.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/textsearch.c b/lib/textsearch.c index 4b7c6075256f..9fbcb44c554f 100644 --- a/lib/textsearch.c +++ b/lib/textsearch.c @@ -267,7 +267,7 @@ struct ts_config *textsearch_prepare(const char *algo, const void *pattern, return ERR_PTR(-EINVAL); ops = lookup_ts_algo(algo); -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES /* * Why not always autoload you may ask. Some users are * in a situation where requesting a module may deadlock, From a1ef5adb4cad43460ebba23c5a78cf4a55bb6a5b Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 8 Jul 2008 19:00:17 +0200 Subject: [PATCH 12/12] remove CONFIG_KMOD from core kernel code Always compile request_module when the kernel allows modules. Signed-off-by: Johannes Berg Signed-off-by: Rusty Russell --- include/linux/kmod.h | 2 +- kernel/exec_domain.c | 2 +- kernel/kmod.c | 2 +- kernel/sysctl.c | 4 ++-- 4 files changed, 5 insertions(+), 5 deletions(-) diff --git a/include/linux/kmod.h b/include/linux/kmod.h index 9bdb28d6660f..0509c4ce4857 100644 --- a/include/linux/kmod.h +++ b/include/linux/kmod.h @@ -25,7 +25,7 @@ #define KMOD_PATH_LEN 256 -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES /* modprobe exit status on success, -ve on error. Return value * usually useless though. */ extern int request_module(const char * name, ...) __attribute__ ((format (printf, 1, 2))); diff --git a/kernel/exec_domain.c b/kernel/exec_domain.c index a9e6bad9f706..c1ef192aa655 100644 --- a/kernel/exec_domain.c +++ b/kernel/exec_domain.c @@ -65,7 +65,7 @@ lookup_exec_domain(u_long personality) goto out; } -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES read_unlock(&exec_domains_lock); request_module("personality-%ld", pers); read_lock(&exec_domains_lock); diff --git a/kernel/kmod.c b/kernel/kmod.c index 8df97d3dfda8..90d7af1c1655 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -42,7 +42,7 @@ extern int max_threads; static struct workqueue_struct *khelper_wq; -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES /* modprobe_path is set via /proc/sys. diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 6b16e16428d8..b859e6b5a767 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -110,7 +110,7 @@ static int min_percpu_pagelist_fract = 8; static int ngroups_max = NGROUPS_MAX; -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES extern char modprobe_path[]; #endif #ifdef CONFIG_CHR_DEV_SG @@ -475,7 +475,7 @@ static struct ctl_table kern_table[] = { .proc_handler = &ftrace_enable_sysctl, }, #endif -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES { .ctl_name = KERN_MODPROBE, .procname = "modprobe",