From 5e458cc0f4770eea45d3c07110f01b3a94c72aa5 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 22 Oct 2008 10:00:13 -0500 Subject: module: simplify load_module. Linus' recent catch of stack overflow in load_module lead me to look at the code. A couple of helpers to get a section address and get objects from a section can help clean things up a little. (And in case you're wondering, the stack size also dropped from 328 to 284 bytes). Signed-off-by: Rusty Russell --- include/linux/module.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/module.h b/include/linux/module.h index 5d2970cdce93..eddf27db442b 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -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); -- cgit v1.2.3 From 730b69d225259565c705f5f5a11cb1aba69568f1 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 22 Oct 2008 10:00:22 -0500 Subject: module: check kernel param length at compile time, not runtime The kparam code tries to handle over-length parameter prefixes at runtime. Not only would I bet this has never been tested, it's not clear that truncating names is a good idea either. So let's check at compile time. We need to move the #define to moduleparam.h to do this, though. Signed-off-by: Rusty Russell --- include/linux/module.h | 2 +- include/linux/moduleparam.h | 6 +++++- 2 files changed, 6 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/module.h b/include/linux/module.h index eddf27db442b..196b499270da 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 { diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index ec624381c844..1eefe6d61b86 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 \ -- cgit v1.2.3 From 9b473de87209fa86eb421b23386693b461612f30 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 22 Oct 2008 10:00:22 -0500 Subject: param: Fix duplicate module prefixes Instead of insisting each new module_param sysfs entry is unique, handle the case where it already exists (for builtin modules). The current code assumes that all identical prefixes are together in the section: true for normal uses, but not necessarily so if someone overrides MODULE_PARAM_PREFIX. More importantly, it's not true with the new "core_param()" code which uses "kernel" as a prefix. This simplifies the caller for the builtin case, at a slight loss of efficiency (we do the lookup every time to see if the directory exists). Signed-off-by: Rusty Russell Cc: Greg Kroah-Hartman --- include/linux/module.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/module.h b/include/linux/module.h index 196b499270da..3bfed013350b 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -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; -- cgit v1.2.3 From 67e67ceaac5bf55dbdceb704ff2d763d438b5373 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 22 Oct 2008 10:00:23 -0500 Subject: core_param() for genuinely core kernel parameters There are a lot of one-liner uses of __setup() in the kernel: they're cumbersome and not queryable (definitely not settable) via /sys. Yet it's ugly to simplify them to module_param(), because by default that inserts a prefix of the module name (usually filename). So, introduce a "core_param". The parameter gets no prefix, but appears in /sys/module/kernel/parameters/ (if non-zero perms arg). I thought about using the name "core", but that's more common than "kernel". And if you create a module called "kernel", you will die a horrible death. Signed-off-by: Rusty Russell --- include/linux/moduleparam.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'include/linux') diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index 1eefe6d61b86..e4af3399ef48 100644 --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -104,6 +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 \ -- cgit v1.2.3 From 0d557dc97f4bb501f086a03d0f00b99a7855d794 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 13 Oct 2008 23:50:09 +0200 Subject: workqueue: introduce create_rt_workqueue create_rt_workqueue will create a real time prioritized workqueue. This is needed for the conversion of stop_machine to a workqueue based implementation. This patch adds yet another parameter to __create_workqueue_key to tell it that we want an rt workqueue. However it looks like we rather should have something like "int type" instead of singlethread, freezable and rt. Signed-off-by: Heiko Carstens Signed-off-by: Rusty Russell Cc: Ingo Molnar --- include/linux/workqueue.h | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) (limited to 'include/linux') diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 5c158c477ac7..89a5a1231ffb 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); -- cgit v1.2.3