From 97d1f15b7ef52c1e9c28dc48b454024bb53a5fd2 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Thu, 23 Mar 2006 03:00:24 -0800 Subject: [PATCH] sem2mutex: kernel/ Semaphore to mutex conversion. The conversion was generated via scripts, and the result was validated automatically via a script as well. Signed-off-by: Arjan van de Ven Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/module.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 77764f22f021..de6312da6bb5 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -39,6 +39,7 @@ #include #include #include +#include #include #include #include @@ -63,15 +64,15 @@ static DEFINE_SPINLOCK(modlist_lock); static DECLARE_MUTEX(module_mutex); static LIST_HEAD(modules); -static DECLARE_MUTEX(notify_mutex); +static DEFINE_MUTEX(notify_mutex); static struct notifier_block * module_notify_list; int register_module_notifier(struct notifier_block * nb) { int err; - down(¬ify_mutex); + mutex_lock(¬ify_mutex); err = notifier_chain_register(&module_notify_list, nb); - up(¬ify_mutex); + mutex_unlock(¬ify_mutex); return err; } EXPORT_SYMBOL(register_module_notifier); @@ -79,9 +80,9 @@ EXPORT_SYMBOL(register_module_notifier); int unregister_module_notifier(struct notifier_block * nb) { int err; - down(¬ify_mutex); + mutex_lock(¬ify_mutex); err = notifier_chain_unregister(&module_notify_list, nb); - up(¬ify_mutex); + mutex_unlock(¬ify_mutex); return err; } EXPORT_SYMBOL(unregister_module_notifier); @@ -1989,9 +1990,9 @@ sys_init_module(void __user *umod, /* Drop lock so they can recurse */ up(&module_mutex); - down(¬ify_mutex); + mutex_lock(¬ify_mutex); notifier_call_chain(&module_notify_list, MODULE_STATE_COMING, mod); - up(¬ify_mutex); + mutex_unlock(¬ify_mutex); /* Start the module */ if (mod->init != NULL) -- cgit v1.2.2 From 6389a385114ae358693f213266de6468ea116c77 Mon Sep 17 00:00:00 2001 From: Ashutosh Naik Date: Thu, 23 Mar 2006 03:00:46 -0800 Subject: [PATCH] kernel/module.c Semaphore to Mutex Conversion for module_mutex This patch converts the module_mutex semaphore to a mutex. Signed-off-by: Ashutosh Naik Cc: Arjan van de Ven Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/module.c | 38 +++++++++++++++++++------------------- 1 file changed, 19 insertions(+), 19 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index de6312da6bb5..fb404299082e 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -61,7 +61,7 @@ static DEFINE_SPINLOCK(modlist_lock); /* List of modules, protected by module_mutex AND modlist_lock */ -static DECLARE_MUTEX(module_mutex); +static DEFINE_MUTEX(module_mutex); static LIST_HEAD(modules); static DEFINE_MUTEX(notify_mutex); @@ -602,7 +602,7 @@ static void free_module(struct module *mod); static void wait_for_zero_refcount(struct module *mod) { /* Since we might sleep for some time, drop the semaphore first */ - up(&module_mutex); + mutex_unlock(&module_mutex); for (;;) { DEBUGP("Looking at refcount...\n"); set_current_state(TASK_UNINTERRUPTIBLE); @@ -611,7 +611,7 @@ static void wait_for_zero_refcount(struct module *mod) schedule(); } current->state = TASK_RUNNING; - down(&module_mutex); + mutex_lock(&module_mutex); } asmlinkage long @@ -628,7 +628,7 @@ sys_delete_module(const char __user *name_user, unsigned int flags) return -EFAULT; name[MODULE_NAME_LEN-1] = '\0'; - if (down_interruptible(&module_mutex) != 0) + if (mutex_lock_interruptible(&module_mutex) != 0) return -EINTR; mod = find_module(name); @@ -677,14 +677,14 @@ sys_delete_module(const char __user *name_user, unsigned int flags) /* Final destruction now noone is using it. */ if (mod->exit != NULL) { - up(&module_mutex); + mutex_unlock(&module_mutex); mod->exit(); - down(&module_mutex); + mutex_lock(&module_mutex); } free_module(mod); out: - up(&module_mutex); + mutex_unlock(&module_mutex); return ret; } @@ -1973,13 +1973,13 @@ sys_init_module(void __user *umod, return -EPERM; /* Only one module load at a time, please */ - if (down_interruptible(&module_mutex) != 0) + if (mutex_lock_interruptible(&module_mutex) != 0) return -EINTR; /* Do all the hard work */ mod = load_module(umod, len, uargs); if (IS_ERR(mod)) { - up(&module_mutex); + mutex_unlock(&module_mutex); return PTR_ERR(mod); } @@ -1988,7 +1988,7 @@ sys_init_module(void __user *umod, stop_machine_run(__link_module, mod, NR_CPUS); /* Drop lock so they can recurse */ - up(&module_mutex); + mutex_unlock(&module_mutex); mutex_lock(¬ify_mutex); notifier_call_chain(&module_notify_list, MODULE_STATE_COMING, mod); @@ -2007,15 +2007,15 @@ sys_init_module(void __user *umod, mod->name); else { module_put(mod); - down(&module_mutex); + mutex_lock(&module_mutex); free_module(mod); - up(&module_mutex); + mutex_unlock(&module_mutex); } return ret; } /* Now it's a first class citizen! */ - down(&module_mutex); + mutex_lock(&module_mutex); mod->state = MODULE_STATE_LIVE; /* Drop initial reference. */ module_put(mod); @@ -2023,7 +2023,7 @@ sys_init_module(void __user *umod, mod->module_init = NULL; mod->init_size = 0; mod->init_text_size = 0; - up(&module_mutex); + mutex_unlock(&module_mutex); return 0; } @@ -2113,7 +2113,7 @@ struct module *module_get_kallsym(unsigned int symnum, { struct module *mod; - down(&module_mutex); + mutex_lock(&module_mutex); list_for_each_entry(mod, &modules, list) { if (symnum < mod->num_symtab) { *value = mod->symtab[symnum].st_value; @@ -2121,12 +2121,12 @@ struct module *module_get_kallsym(unsigned int symnum, strncpy(namebuf, mod->strtab + mod->symtab[symnum].st_name, 127); - up(&module_mutex); + mutex_unlock(&module_mutex); return mod; } symnum -= mod->num_symtab; } - up(&module_mutex); + mutex_unlock(&module_mutex); return NULL; } @@ -2169,7 +2169,7 @@ static void *m_start(struct seq_file *m, loff_t *pos) struct list_head *i; loff_t n = 0; - down(&module_mutex); + mutex_lock(&module_mutex); list_for_each(i, &modules) { if (n++ == *pos) break; @@ -2190,7 +2190,7 @@ static void *m_next(struct seq_file *m, void *p, loff_t *pos) static void m_stop(struct seq_file *m, void *p) { - up(&module_mutex); + mutex_unlock(&module_mutex); } static int m_show(struct seq_file *m, void *p) -- cgit v1.2.2 From 24277dda3a54aa5e6265487e1a3091e27f3c0c45 Mon Sep 17 00:00:00 2001 From: Davi Arnaut Date: Fri, 24 Mar 2006 03:18:43 -0800 Subject: [PATCH] strndup_user: convert module Change hand-coded userspace string copying to strndup_user. Signed-off-by: Davi Arnaut Cc: David Howells Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/module.c | 19 +++---------------- 1 file changed, 3 insertions(+), 16 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index fb404299082e..54623c714bba 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1572,7 +1572,6 @@ static struct module *load_module(void __user *umod, exportindex, modindex, obsparmindex, infoindex, gplindex, crcindex, gplcrcindex, versindex, pcpuindex, gplfutureindex, gplfuturecrcindex; - long arglen; struct module *mod; long err = 0; void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */ @@ -1691,23 +1690,11 @@ static struct module *load_module(void __user *umod, } /* Now copy in args */ - arglen = strlen_user(uargs); - if (!arglen) { - err = -EFAULT; - goto free_hdr; - } - args = kmalloc(arglen, GFP_KERNEL); - if (!args) { - err = -ENOMEM; + args = strndup_user(uargs, ~0UL >> 1); + if (IS_ERR(args)) { + err = PTR_ERR(args); goto free_hdr; } - if (copy_from_user(args, uargs, arglen) != 0) { - err = -EFAULT; - goto free_mod; - } - - /* Userspace could have altered the string after the strlen_user() */ - args[arglen - 1] = '\0'; if (find_module(mod->name)) { err = -EEXIST; -- cgit v1.2.2 From 8d3b33f67fdc0fb364a1ef6d8fbbea7c2e4e6c98 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Sat, 25 Mar 2006 03:07:05 -0800 Subject: [PATCH] Remove MODULE_PARM MODULE_PARM was actually breaking: recent gcc version optimize them out as unused. It's time to replace the last users, which are generally in the most unloved drivers anyway. Signed-off-by: Rusty Russell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/module.c | 183 ++++---------------------------------------------------- 1 file changed, 11 insertions(+), 172 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 54623c714bba..ddfe45ac2fd1 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -233,24 +233,6 @@ static unsigned long __find_symbol(const char *name, return 0; } -/* Find a symbol in this elf symbol table */ -static unsigned long find_local_symbol(Elf_Shdr *sechdrs, - unsigned int symindex, - const char *strtab, - const char *name) -{ - unsigned int i; - Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr; - - /* Search (defined) internal symbols first. */ - for (i = 1; i < sechdrs[symindex].sh_size/sizeof(*sym); i++) { - if (sym[i].st_shndx != SHN_UNDEF - && strcmp(name, strtab + sym[i].st_name) == 0) - return sym[i].st_value; - } - return 0; -} - /* Search for module by name: must hold module_mutex. */ static struct module *find_module(const char *name) { @@ -785,139 +767,6 @@ static struct module_attribute *modinfo_attrs[] = { NULL, }; -#ifdef CONFIG_OBSOLETE_MODPARM -/* Bounds checking done below */ -static int obsparm_copy_string(const char *val, struct kernel_param *kp) -{ - strcpy(kp->arg, val); - return 0; -} - -static int set_obsolete(const char *val, struct kernel_param *kp) -{ - unsigned int min, max; - unsigned int size, maxsize; - int dummy; - char *endp; - const char *p; - struct obsolete_modparm *obsparm = kp->arg; - - if (!val) { - printk(KERN_ERR "Parameter %s needs an argument\n", kp->name); - return -EINVAL; - } - - /* type is: [min[-max]]{b,h,i,l,s} */ - p = obsparm->type; - min = simple_strtol(p, &endp, 10); - if (endp == obsparm->type) - min = max = 1; - else if (*endp == '-') { - p = endp+1; - max = simple_strtol(p, &endp, 10); - } else - max = min; - switch (*endp) { - case 'b': - return param_array(kp->name, val, min, max, obsparm->addr, - 1, param_set_byte, &dummy); - case 'h': - return param_array(kp->name, val, min, max, obsparm->addr, - sizeof(short), param_set_short, &dummy); - case 'i': - return param_array(kp->name, val, min, max, obsparm->addr, - sizeof(int), param_set_int, &dummy); - case 'l': - return param_array(kp->name, val, min, max, obsparm->addr, - sizeof(long), param_set_long, &dummy); - case 's': - return param_array(kp->name, val, min, max, obsparm->addr, - sizeof(char *), param_set_charp, &dummy); - - case 'c': - /* Undocumented: 1-5c50 means 1-5 strings of up to 49 chars, - and the decl is "char xxx[5][50];" */ - p = endp+1; - maxsize = simple_strtol(p, &endp, 10); - /* We check lengths here (yes, this is a hack). */ - p = val; - while (p[size = strcspn(p, ",")]) { - if (size >= maxsize) - goto oversize; - p += size+1; - } - if (size >= maxsize) - goto oversize; - return param_array(kp->name, val, min, max, obsparm->addr, - maxsize, obsparm_copy_string, &dummy); - } - printk(KERN_ERR "Unknown obsolete parameter type %s\n", obsparm->type); - return -EINVAL; - oversize: - printk(KERN_ERR - "Parameter %s doesn't fit in %u chars.\n", kp->name, maxsize); - return -EINVAL; -} - -static int obsolete_params(const char *name, - char *args, - struct obsolete_modparm obsparm[], - unsigned int num, - Elf_Shdr *sechdrs, - unsigned int symindex, - const char *strtab) -{ - struct kernel_param *kp; - unsigned int i; - int ret; - - kp = kmalloc(sizeof(kp[0]) * num, GFP_KERNEL); - if (!kp) - return -ENOMEM; - - for (i = 0; i < num; i++) { - char sym_name[128 + sizeof(MODULE_SYMBOL_PREFIX)]; - - snprintf(sym_name, sizeof(sym_name), "%s%s", - MODULE_SYMBOL_PREFIX, obsparm[i].name); - - kp[i].name = obsparm[i].name; - kp[i].perm = 000; - kp[i].set = set_obsolete; - kp[i].get = NULL; - obsparm[i].addr - = (void *)find_local_symbol(sechdrs, symindex, strtab, - sym_name); - if (!obsparm[i].addr) { - printk("%s: falsely claims to have parameter %s\n", - name, obsparm[i].name); - ret = -EINVAL; - goto out; - } - kp[i].arg = &obsparm[i]; - } - - ret = parse_args(name, args, kp, num, NULL); - out: - kfree(kp); - return ret; -} -#else -static int obsolete_params(const char *name, - char *args, - struct obsolete_modparm obsparm[], - unsigned int num, - Elf_Shdr *sechdrs, - unsigned int symindex, - const char *strtab) -{ - if (num != 0) - printk(KERN_WARNING "%s: Ignoring obsolete parameters\n", - name); - return 0; -} -#endif /* CONFIG_OBSOLETE_MODPARM */ - static const char vermagic[] = VERMAGIC_STRING; #ifdef CONFIG_MODVERSIONS @@ -1874,27 +1723,17 @@ static struct module *load_module(void __user *umod, set_fs(old_fs); mod->args = args; - if (obsparmindex) { - err = obsolete_params(mod->name, mod->args, - (struct obsolete_modparm *) - sechdrs[obsparmindex].sh_addr, - sechdrs[obsparmindex].sh_size - / sizeof(struct obsolete_modparm), - sechdrs, symindex, - (char *)sechdrs[strindex].sh_addr); - if (setupindex) - printk(KERN_WARNING "%s: Ignoring new-style " - "parameters in presence of obsolete ones\n", - mod->name); - } else { - /* 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); - } + if (obsparmindex) + printk(KERN_WARNING "%s: Ignoring obsolete parameters\n", + mod->name); + + /* 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); if (err < 0) goto arch_cleanup; -- cgit v1.2.2 From e041c683412d5bf44dc2b109053e3b837b71742d Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Mon, 27 Mar 2006 01:16:30 -0800 Subject: [PATCH] Notifier chain update: API changes The kernel's implementation of notifier chains is unsafe. There is no protection against entries being added to or removed from a chain while the chain is in use. The issues were discussed in this thread: http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2 We noticed that notifier chains in the kernel fall into two basic usage classes: "Blocking" chains are always called from a process context and the callout routines are allowed to sleep; "Atomic" chains can be called from an atomic context and the callout routines are not allowed to sleep. We decided to codify this distinction and make it part of the API. Therefore this set of patches introduces three new, parallel APIs: one for blocking notifiers, one for atomic notifiers, and one for "raw" notifiers (which is really just the old API under a new name). New kinds of data structures are used for the heads of the chains, and new routines are defined for registration, unregistration, and calling a chain. The three APIs are explained in include/linux/notifier.h and their implementation is in kernel/sys.c. With atomic and blocking chains, the implementation guarantees that the chain links will not be corrupted and that chain callers will not get messed up by entries being added or removed. For raw chains the implementation provides no guarantees at all; users of this API must provide their own protections. (The idea was that situations may come up where the assumptions of the atomic and blocking APIs are not appropriate, so it should be possible for users to handle these things in their own way.) There are some limitations, which should not be too hard to live with. For atomic/blocking chains, registration and unregistration must always be done in a process context since the chain is protected by a mutex/rwsem. Also, a callout routine for a non-raw chain must not try to register or unregister entries on its own chain. (This did happen in a couple of places and the code had to be changed to avoid it.) Since atomic chains may be called from within an NMI handler, they cannot use spinlocks for synchronization. Instead we use RCU. The overhead falls almost entirely in the unregister routine, which is okay since unregistration is much less frequent that calling a chain. Here is the list of chains that we adjusted and their classifications. None of them use the raw API, so for the moment it is only a placeholder. ATOMIC CHAINS ------------- arch/i386/kernel/traps.c: i386die_chain arch/ia64/kernel/traps.c: ia64die_chain arch/powerpc/kernel/traps.c: powerpc_die_chain arch/sparc64/kernel/traps.c: sparc64die_chain arch/x86_64/kernel/traps.c: die_chain drivers/char/ipmi/ipmi_si_intf.c: xaction_notifier_list kernel/panic.c: panic_notifier_list kernel/profile.c: task_free_notifier net/bluetooth/hci_core.c: hci_notifier net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_chain net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_expect_chain net/ipv6/addrconf.c: inet6addr_chain net/netfilter/nf_conntrack_core.c: nf_conntrack_chain net/netfilter/nf_conntrack_core.c: nf_conntrack_expect_chain net/netlink/af_netlink.c: netlink_chain BLOCKING CHAINS --------------- arch/powerpc/platforms/pseries/reconfig.c: pSeries_reconfig_chain arch/s390/kernel/process.c: idle_chain arch/x86_64/kernel/process.c idle_notifier drivers/base/memory.c: memory_chain drivers/cpufreq/cpufreq.c cpufreq_policy_notifier_list drivers/cpufreq/cpufreq.c cpufreq_transition_notifier_list drivers/macintosh/adb.c: adb_client_list drivers/macintosh/via-pmu.c sleep_notifier_list drivers/macintosh/via-pmu68k.c sleep_notifier_list drivers/macintosh/windfarm_core.c wf_client_list drivers/usb/core/notify.c usb_notifier_list drivers/video/fbmem.c fb_notifier_list kernel/cpu.c cpu_chain kernel/module.c module_notify_list kernel/profile.c munmap_notifier kernel/profile.c task_exit_notifier kernel/sys.c reboot_notifier_list net/core/dev.c netdev_chain net/decnet/dn_dev.c: dnaddr_chain net/ipv4/devinet.c: inetaddr_chain It's possible that some of these classifications are wrong. If they are, please let us know or submit a patch to fix them. Note that any chain that gets called very frequently should be atomic, because the rwsem read-locking used for blocking chains is very likely to incur cache misses on SMP systems. (However, if the chain's callout routines may sleep then the chain cannot be atomic.) The patch set was written by Alan Stern and Chandra Seetharaman, incorporating material written by Keith Owens and suggestions from Paul McKenney and Andrew Morton. [jes@sgi.com: restructure the notifier chain initialization macros] Signed-off-by: Alan Stern Signed-off-by: Chandra Seetharaman Signed-off-by: Jes Sorensen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/module.c | 20 +++++--------------- 1 file changed, 5 insertions(+), 15 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index ddfe45ac2fd1..4fafd58038a0 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -64,26 +64,17 @@ static DEFINE_SPINLOCK(modlist_lock); static DEFINE_MUTEX(module_mutex); static LIST_HEAD(modules); -static DEFINE_MUTEX(notify_mutex); -static struct notifier_block * module_notify_list; +static BLOCKING_NOTIFIER_HEAD(module_notify_list); int register_module_notifier(struct notifier_block * nb) { - int err; - mutex_lock(¬ify_mutex); - err = notifier_chain_register(&module_notify_list, nb); - mutex_unlock(¬ify_mutex); - return err; + return blocking_notifier_chain_register(&module_notify_list, nb); } EXPORT_SYMBOL(register_module_notifier); int unregister_module_notifier(struct notifier_block * nb) { - int err; - mutex_lock(¬ify_mutex); - err = notifier_chain_unregister(&module_notify_list, nb); - mutex_unlock(¬ify_mutex); - return err; + return blocking_notifier_chain_unregister(&module_notify_list, nb); } EXPORT_SYMBOL(unregister_module_notifier); @@ -1816,9 +1807,8 @@ sys_init_module(void __user *umod, /* Drop lock so they can recurse */ mutex_unlock(&module_mutex); - mutex_lock(¬ify_mutex); - notifier_call_chain(&module_notify_list, MODULE_STATE_COMING, mod); - mutex_unlock(¬ify_mutex); + blocking_notifier_call_chain(&module_notify_list, + MODULE_STATE_COMING, mod); /* Start the module */ if (mod->init != NULL) -- cgit v1.2.2 From f83ca9fe3ee390755f18b4a7780c25ce593b484a Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Tue, 28 Mar 2006 01:56:20 -0800 Subject: [PATCH] symversion warning fix gcc-4.2: kernel/module.c: In function '__find_symbol': kernel/module.c:158: warning: the address of '__start___kcrctab', will always evaluate as 'true' kernel/module.c:165: warning: the address of '__start___kcrctab_gpl', will always evaluate as 'true' kernel/module.c:182: warning: the address of '__start___kcrctab_gpl_future', will always evaluate as 'true' Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/module.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 4fafd58038a0..bd088a7c1499 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -127,7 +127,7 @@ extern const unsigned long __start___kcrctab_gpl_future[]; #ifndef CONFIG_MODVERSIONS #define symversion(base, idx) NULL #else -#define symversion(base, idx) ((base) ? ((base) + (idx)) : NULL) +#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL) #endif /* lookup symbol in given range of kernel_symbols */ -- cgit v1.2.2