[PATCH 3/3] Allow arbitrary number of init funcs in modules

[PATCH 3/3] Allow arbitrary number of init funcs in modules

[Rusty Russell]

This patch requires some explanation, see description fields below.

Thanks to Andrew for prodding, and DaveM for the hard questions.

Feedback is extremely welcome,
Rusty.
--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

Name: Allow Arbitrary Number of Init and Exit Functions
Author: Rusty Russell
Status: Tested on 2.5.73
Depends: Misc/unique_id.patch.gz

D: One longstanding complaint is that modules can only have one
D: module_init, and one module_exit (builtin code can have multiple
D: __initcall however).  This means, for example, that it is not
D: possible to write a "module_proc_entry(name, readfn)" function
D: which can be used like so:
D: 
D:   module_init(myinitfn);
D:   module_cleanup(myinitfn);
D:   module_proc_entry("some/path/foo", read_foo);
D: 
D: The reason we don't allow multiple init functions in modules: if
D: one fails, we won't know what to do.  The solution is to explicitly
D: pair them, hence module_init_exit(), with a priority arg.
D: 
D: If the module fails to load the exit function will be called
D: corresponding to each init function which was called, in backwards
D: order.  All exit functions are called on module removal.
D: 
D: For non-modules, the exit arg is discarded, and the initcalls are
D: run in priority order at boot (order within priorities is still
D: controlled by linking, as previously).  This means we can also get
D: rid of the initcall levels at link time and simply use priorities.
D: 
D: This patch also uses kallsyms to print function names when 
D: "initcall_debug" is set.

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15772-linux-2.5.73/arch/i386/vmlinux.lds.S .15772-linux-2.5.73.updated/arch/i386/vmlinux.lds.S
--- .15772-linux-2.5.73/arch/i386/vmlinux.lds.S	2003-06-15 11:29:47.000000000 +1000
+++ .15772-linux-2.5.73.updated/arch/i386/vmlinux.lds.S	2003-06-23 18:10:41.000000000 +1000
@@ -69,13 +69,7 @@ SECTIONS
   __stop___param = .;
   __initcall_start = .;
   .initcall.init : {
-	*(.initcall1.init) 
-	*(.initcall2.init) 
-	*(.initcall3.init) 
-	*(.initcall4.init) 
-	*(.initcall5.init) 
-	*(.initcall6.init) 
-	*(.initcall7.init)
+	*(.initcall.init) 
   }
   __initcall_end = .;
   __con_initcall_start = .;
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15772-linux-2.5.73/include/linux/init.h .15772-linux-2.5.73.updated/include/linux/init.h
--- .15772-linux-2.5.73/include/linux/init.h	2003-06-15 11:30:08.000000000 +1000
+++ .15772-linux-2.5.73.updated/include/linux/init.h	2003-06-23 18:17:22.000000000 +1000
@@ -2,6 +2,7 @@
 #define _LINUX_INIT_H
 
 #include <linux/config.h>
+#include <linux/stringify.h>
 
 /* These macros are used to mark some functions or 
  * initialized data (doesn't apply to uninitialized data)
@@ -65,34 +66,48 @@ typedef void (*exitcall_t)(void);
 
 extern initcall_t __con_initcall_start, __con_initcall_end;
 extern initcall_t __security_initcall_start, __security_initcall_end;
+
+struct module_init_exit
+{
+	int prio;
+	initcall_t init;
+	exitcall_t exit;
+};
+
+struct kernel_init
+{
+	int prio;
+	initcall_t init;
+};
 #endif
-  
+
 #ifndef MODULE
 
 #ifndef __ASSEMBLY__
+/* Suppress unused warning on exitfn, and test type. */
+#define __exitcall(fn)							\
+static inline exitcall_t __unique_id(exit_test)(void) { return fn; }
 
-/* initcalls are now grouped by functionality into separate 
- * subsections. Ordering inside the subsections is determined
- * by link order. 
- * For backwards compatibility, initcall() puts the call in 
- * the device init subsection.
- */
-
-#define __define_initcall(level,fn) \
-	static initcall_t __initcall_##fn __attribute__ ((unused,__section__ (".initcall" level ".init"))) = fn
-
-#define core_initcall(fn)		__define_initcall("1",fn)
-#define postcore_initcall(fn)		__define_initcall("2",fn)
-#define arch_initcall(fn)		__define_initcall("3",fn)
-#define subsys_initcall(fn)		__define_initcall("4",fn)
-#define fs_initcall(fn)			__define_initcall("5",fn)
-#define device_initcall(fn)		__define_initcall("6",fn)
-#define late_initcall(fn)		__define_initcall("7",fn)
+/* Pair of calls: one called at boot, one at exit (ie. never, when not
+   a module).  Unlike module_init, you can have any number of these.
+   prio controls ordering: negative runs before module_init, positive after.
+   Within a priority, link order rules.
+*/
+#define module_init_exit(prio, initfn, exitfn)			\
+	__exitcall(exitfn);					\
+	static struct kernel_init __initcall_##initfn		\
+	 __attribute__((unused,__section__ (".initcall.init")))	\
+	= { prio, initfn }
 
-#define __initcall(fn) device_initcall(fn)
+#define core_initcall(fn)		module_init_exit(-5000, fn, NULL)
+#define postcore_initcall(fn)		module_init_exit(-4000, fn, NULL)
+#define arch_initcall(fn)		module_init_exit(-3000, fn, NULL)
+#define subsys_initcall(fn)		module_init_exit(-2000, fn, NULL)
+#define fs_initcall(fn)			module_init_exit(-1000, fn, NULL)
+#define device_initcall(fn)		module_init_exit(0, fn, NULL)
+#define late_initcall(fn)		module_init_exit(1000, fn, NULL)
 
-#define __exitcall(fn)							\
-	static exitcall_t __exitcall_##fn __exit_call = fn
+#define __initcall(fn)			device_initcall(fn)
 
 #define console_initcall(fn) \
 	static initcall_t __initcall_##fn __attribute__ ((unused,__section__ (".con_initcall.init")))=fn
@@ -112,8 +127,6 @@ struct obs_kernel_param {
 		 __attribute__((unused,__section__ (".init.setup")))	\
 		= { __setup_str_##fn, fn }
 
-#endif /* __ASSEMBLY__ */
-
 /**
  * module_init() - driver initialization entry point
  * @x: function to be run at kernel boot time or module insertion
@@ -135,6 +148,7 @@ struct obs_kernel_param {
  * There can only be one per module.
  */
 #define module_exit(x)	__exitcall(x);
+#endif /* __ASSEMBLY__ */
 
 #else /* MODULE */
 
@@ -149,25 +163,27 @@ struct obs_kernel_param {
 
 #define security_initcall(fn)		module_init(fn)
 
-/* These macros create a dummy inline: gcc 2.9x does not count alias
- as usage, hence the `unused function' warning when __init functions
- are declared static. We use the dummy __*_module_inline functions
- both to kill the warning and check the type of the init/cleanup
- function. */
-
-/* Each module must use one module_init(), or one no_module_init */
-#define module_init(initfn)					\
-	static inline initcall_t __inittest(void)		\
-	{ return initfn; }					\
-	int init_module(void) __attribute__((alias(#initfn)));
+/* Each module can have one module_init(). */
+#define module_init(initfn)						\
+	static struct module_init_exit module_init			\
+	 __attribute__ ((unused,__section__ ("__initexit")))	\
+	= { 0, initfn, NULL };
 
-/* This is only required if you want to be unloadable. */
-#define module_exit(exitfn)					\
-	static inline exitcall_t __exittest(void)		\
-	{ return exitfn; }					\
-	void cleanup_module(void) __attribute__((alias(#exitfn)));
+/* If you have a module_init, and want to be unloadable, you need this too. */
+#define module_exit(exitfn)						\
+	static struct module_init_exit module_exit			\
+	 __attribute__ ((unused,__section__ ("__initexit")))	\
+	= { 0, NULL, exitfn };
 
 #define __setup(str,func) /* nothing */
+
+/* Pair of calls: one called at init, one at exit.  Unlike
+   module_init/module_exit, you can have any number of these: ordering is
+   controlled by priority, in ascending order: module_init is 0. */
+#define module_init_exit(prio, initfn, exitfn)				\
+	static struct module_init_exit __unique_id(mie)			\
+	 __attribute__ ((unused,__section__ ("__initexit")))		\
+	= { prio, initfn, exitfn }
 #endif
 
 /* Data marked not to be saved by software_suspend() */
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15772-linux-2.5.73/include/linux/module.h .15772-linux-2.5.73.updated/include/linux/module.h
--- .15772-linux-2.5.73/include/linux/module.h	2003-06-23 17:29:39.000000000 +1000
+++ .15772-linux-2.5.73.updated/include/linux/module.h	2003-06-23 17:29:42.000000000 +1000
@@ -203,9 +203,6 @@ struct module
 	unsigned int num_exentries;
 	const struct exception_table_entry *extable;
 
-	/* Startup function. */
-	int (*init)(void);
-
 	/* If this is non-NULL, vfree after init() returns */
 	void *module_init;
 
@@ -224,6 +221,10 @@ struct module
 	/* Am I GPL-compatible */
 	int license_gplok;
 
+	/* Pairs of init/exit functions. */
+	struct module_init_exit *ie_pairs;
+	unsigned int num_ie_pairs;
+
 #ifdef CONFIG_MODULE_UNLOAD
 	/* Reference counts */
 	struct module_ref ref[NR_CPUS];
@@ -233,9 +234,6 @@ struct module
 
 	/* Who is waiting for us to be unloaded */
 	struct task_struct *waiter;
-
-	/* Destruction function. */
-	void (*exit)(void);
 #endif
 
 #ifdef CONFIG_KALLSYMS
@@ -449,10 +447,6 @@ extern struct module __this_module;
 struct module __this_module
 __attribute__((section(".gnu.linkonce.this_module"))) = {
 	.name = __stringify(KBUILD_MODNAME),
-	.init = init_module,
-#ifdef CONFIG_MODULE_UNLOAD
-	.exit = cleanup_module,
-#endif
 };
 #endif /* KBUILD_MODNAME */
 #endif /* MODULE */
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15772-linux-2.5.73/init/main.c .15772-linux-2.5.73.updated/init/main.c
--- .15772-linux-2.5.73/init/main.c	2003-06-17 16:57:33.000000000 +1000
+++ .15772-linux-2.5.73.updated/init/main.c	2003-06-23 18:51:34.000000000 +1000
@@ -38,6 +38,7 @@
 #include <linux/moduleparam.h>
 #include <linux/writeback.h>
 #include <linux/cpu.h>
+#include <linux/kallsyms.h>
 
 #include <asm/io.h>
 #include <asm/bugs.h>
@@ -478,34 +479,67 @@ __setup("initcall_debug", initcall_debug
 
 struct task_struct *child_reaper = &init_task;
 
-extern initcall_t __initcall_start, __initcall_end;
-
-static void __init do_initcalls(void)
+static void do_initcall(initcall_t call)
 {
-	initcall_t *call;
+	char *msg = NULL;
+	char buf[128];
+	char *m;
+	unsigned long d;
 	int count = preempt_count();
 
-	for (call = &__initcall_start; call < &__initcall_end; call++) {
-		char *msg;
+	if (initcall_debug)
+		printk("calling initcall 0x%p %s\n", *call,
+		       kallsyms_lookup((long)call, &d, &d, &m, buf) ?: "");
+	call();
 
-		if (initcall_debug)
-			printk("calling initcall 0x%p\n", *call);
+	if (preempt_count() != count) {
+		msg = "preemption imbalance";
+		preempt_count() = count;
+	}
+	if (irqs_disabled()) {
+		msg = "disabled interrupts";
+		local_irq_enable();
+	}
+	if (msg) {
+		printk("error in initcall at 0x%p %s: "
+		       "returned with %s\n", *call,
+		       kallsyms_lookup((long)call, &d, &d, &m, buf) ?: "",
+		       msg);
+	}
+}
 
-		(*call)();
+/* Defined by linker magic. */
+extern struct kernel_init __initcall_start[], __initcall_end[];
 
-		msg = NULL;
-		if (preempt_count() != count) {
-			msg = "preemption imbalance";
-			preempt_count() = count;
-		}
-		if (irqs_disabled()) {
-			msg = "disabled interrupts";
-			local_irq_enable();
-		}
-		if (msg) {
-			printk("error in initcall at 0x%p: "
-				"returned with %s\n", *call, msg);
+/* Find first initfunc minimally >= this prio level. */
+static struct kernel_init *find_next_prio(int min_prio_todo)
+{
+	struct kernel_init *i, *best;
+
+	best = NULL;
+	for (i = __initcall_start; i < __initcall_end; i++) {
+		if (i->prio >= min_prio_todo
+		    && (!best || i->prio < best->prio))
+			best = i;
+	}
+	return best;
+}
+
+static void __init do_initcalls(void)
+{
+	struct kernel_init *next, *i;
+	int min_prio_todo = INT_MIN;
+
+	/* This is O(num calls * num levels), which is OK. */
+	while ((next = find_next_prio(min_prio_todo)) != NULL) {
+		if (initcall_debug)
+			printk("Doing priority %i initcalls:\n", next->prio);
+		/* Now call all at that priority. */
+		for (i = next; i < __initcall_end; i++) {
+			if (i->prio == next->prio)
+				do_initcall(i->init);
 		}
+		min_prio_todo = next->prio+1;
 	}
 
 	/* Make sure there is no pending stuff from the initcall sequence */
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15772-linux-2.5.73/kernel/module.c .15772-linux-2.5.73.updated/kernel/module.c
--- .15772-linux-2.5.73/kernel/module.c	2003-06-15 11:30:11.000000000 +1000
+++ .15772-linux-2.5.73.updated/kernel/module.c	2003-06-23 17:29:42.000000000 +1000
@@ -91,13 +91,6 @@ static inline int strong_try_module_get(
 	return try_module_get(mod);
 }
 
-/* Stub function for modules which don't have an initfn */
-int init_module(void)
-{
-	return 0;
-}
-EXPORT_SYMBOL(init_module);
-
 /* Find a module section: 0 means not found. */
 static unsigned int find_sec(Elf_Ehdr *hdr,
 			     Elf_Shdr *sechdrs,
@@ -619,11 +612,16 @@ static inline int try_force(unsigned int
 }
 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
 
-/* Stub function for modules which don't have an exitfn */
-void cleanup_module(void)
+/* Need as many exits as inits to unload. */
+static int can_unload(unsigned int num_pairs, struct module_init_exit *pairs)
 {
+	int i, balance = 0;
+
+	for (i = 0; i < num_pairs; i++)
+		balance += (pairs->init ? 1 : 0) - (pairs->exit ? 1 : 0);
+
+	return balance == 0;
 }
-EXPORT_SYMBOL(cleanup_module);
 
 static void wait_for_zero_refcount(struct module *mod)
 {
@@ -645,6 +643,7 @@ sys_delete_module(const char __user *nam
 {
 	struct module *mod;
 	char name[MODULE_NAME_LEN];
+	unsigned int i;
 	int ret, forced = 0;
 
 	if (!capable(CAP_SYS_MODULE))
@@ -678,9 +677,8 @@ sys_delete_module(const char __user *nam
 		goto out;
 	}
 
-	/* If it has an init func, it must have an exit func to unload */
-	if ((mod->init != init_module && mod->exit == cleanup_module)
-	    || mod->unsafe) {
+	/* Init and exit functions must balance to unload. */
+	if (!can_unload(mod->num_ie_pairs, mod->ie_pairs) || mod->unsafe) {
 		forced = try_force(flags);
 		if (!forced) {
 			/* This module can't be removed */
@@ -713,8 +711,10 @@ sys_delete_module(const char __user *nam
 	if (!forced && module_refcount(mod) != 0)
 		wait_for_zero_refcount(mod);
 
-	/* Final destruction now noone is using it. */
-	mod->exit();
+	/* Final destruction now noone is using it, reverse priority order. */
+	for (i = mod->num_ie_pairs - 1; i >= 0; i--)
+		if (mod->ie_pairs[i].exit)
+			mod->ie_pairs[i].exit();
 	free_module(mod);
 
  out:
@@ -741,7 +741,7 @@ static void print_unload_info(struct seq
 		seq_printf(m, "[unsafe],");
 	}
 
-	if (mod->init != init_module && mod->exit == cleanup_module) {
+	if (!can_unload(mod->num_ie_pairs, mod->ie_pairs)) {
 		printed_something = 1;
 		seq_printf(m, "[permanent],");
 	}
@@ -1351,6 +1351,23 @@ static void add_kallsyms(struct module *
 }
 #endif
 
+/* Order init_exit pairs in ascending priority.  num is small. */
+static void sort_ie_pairs(struct module_init_exit *ie_pairs, unsigned int num)
+{
+	unsigned int i, j;
+	struct module_init_exit tmp;
+
+	for (i = 0; i < num; i++) {
+		for (j = i; j+1 < num; j++) {
+			if (ie_pairs[j].prio > ie_pairs[j+1].prio) {
+				tmp = ie_pairs[j];
+				ie_pairs[j] = ie_pairs[j+1];
+				ie_pairs[j+1] = tmp;
+			}
+		}
+	}
+}
+
 /* 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,
@@ -1362,7 +1379,7 @@ static struct module *load_module(void _
 	char *secstrings, *args, *modmagic, *strtab = NULL;
 	unsigned int i, symindex = 0, strindex = 0, setupindex, exindex,
 		exportindex, modindex, obsparmindex, infoindex, gplindex,
-		crcindex, gplcrcindex, versindex, pcpuindex;
+		crcindex, gplcrcindex, versindex, pcpuindex, iepairindex;
 	long arglen;
 	struct module *mod;
 	long err = 0;
@@ -1437,6 +1454,7 @@ static struct module *load_module(void _
 	obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
 	versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
 	infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
+	iepairindex = find_sec(hdr, sechdrs, secstrings, "__initexit");
 	pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
 
 	/* Don't keep modinfo section */
@@ -1587,6 +1605,12 @@ static struct module *load_module(void _
 	mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
 	mod->extable = (void *)sechdrs[exindex].sh_addr;
 
+	/* Set up init/exit pair table, and sort into prio order. */
+	mod->num_ie_pairs = sechdrs[iepairindex].sh_size
+		/ sizeof(struct module_init_exit);
+	mod->ie_pairs = (void *)sechdrs[iepairindex].sh_addr;
+	sort_ie_pairs(mod->ie_pairs, mod->num_ie_pairs);
+
 	/* Now do relocations. */
 	for (i = 1; i < hdr->e_shnum; i++) {
 		const char *strtab = (char *)sechdrs[strindex].sh_addr;
@@ -1661,7 +1685,7 @@ sys_init_module(void __user *umod,
 		const char __user *uargs)
 {
 	struct module *mod;
-	int ret;
+	int i, ret;
 
 	/* Must have permission */
 	if (!capable(CAP_SYS_MODULE))
@@ -1700,22 +1724,13 @@ sys_init_module(void __user *umod,
 	up(&notify_mutex);
 
 	/* Start the module */
-	ret = mod->init();
-	if (ret < 0) {
-		/* Init routine failed: abort.  Try to protect us from
-                   buggy refcounters. */
-		mod->state = MODULE_STATE_GOING;
-		synchronize_kernel();
-		if (mod->unsafe)
-			printk(KERN_ERR "%s: module is now stuck!\n",
-			       mod->name);
-		else {
-			module_put(mod);
-			down(&module_mutex);
-			free_module(mod);
-			up(&module_mutex);
+	for (i = 0; i < mod->num_ie_pairs; i++) {
+		ret = mod->ie_pairs[i].init();
+		if (ret != 0) {
+			DEBUGP("%s: init/exit pair init=%p failed: %i\n",
+			       mod->name, mod->ie_pairs[i].init, ret);
+			goto unwind_iepairs;
 		}
-		return ret;
 	}
 
 	/* Now it's a first class citizen! */
@@ -1729,6 +1744,25 @@ sys_init_module(void __user *umod,
 	up(&module_mutex);
 
 	return 0;
+
+unwind_iepairs:
+	/* Init routine failed: abort.  Try to protect us from
+	   buggy refcounters. */
+	mod->state = MODULE_STATE_GOING;
+	module_put(mod);
+	synchronize_kernel();
+	if (module_refcount(mod)) {
+		printk(KERN_ERR "%s: module is now stuck!\n", mod->name);
+		return ret;
+	}
+
+	down(&module_mutex);
+	while (--i >= 0)
+		if (mod->ie_pairs[i].exit)
+			mod->ie_pairs[i].exit();
+	free_module(mod);
+	up(&module_mutex);
+	return ret;
 }
 
 static inline int within(unsigned long addr, void *start, unsigned long size)

Re: [PATCH 3/3] Allow arbitrary number of init funcs in modules

[Jonathan Corbet]

> Feedback is extremely welcome,

OK...you asked for it.  I found three separate bugs, two of them oopsed the
system, and the other prevented module unloading.  Did you try it with
CONFIG_MODULE_UNLOAD? :) You also need to test for null init functions,
because the module_init/module_exit mode creates them.  Patch appended.

Also...some guy once posted (http://lwn.net/Articles/22763/):

	I appeciate the series in modernizing modules, but just FYI, I
	don't think the old-style init_module/cleanup_module stuff will
	break any time soon: there are still a large number of drivers
	which use it, and there's not much point making such changes.

This patch breaks the old init_module/cleanup_module scheme; those
functions no longer get called.  Was that intentional?

jon

P.S. Beyond that, I think the patch makes sense :)

Jonathan Corbet
Executive editor, LWN.net
corbet@lwn.net


--- 2.5.73-rr/kernel/module.c	Tue Jun 24 02:58:32 2003
+++ 2.5.73/kernel/module.c	Tue Jun 24 03:00:36 2003
@@ -617,9 +617,10 @@
 {
 	int i, balance = 0;
 
-	for (i = 0; i < num_pairs; i++)
+	for (i = 0; i < num_pairs; i++) {
 		balance += (pairs->init ? 1 : 0) - (pairs->exit ? 1 : 0);
-
+		pairs++;
+	}
 	return balance == 0;
 }
 
@@ -643,7 +644,7 @@
 {
 	struct module *mod;
 	char name[MODULE_NAME_LEN];
-	unsigned int i;
+	int i;
 	int ret, forced = 0;
 
 	if (!capable(CAP_SYS_MODULE))
@@ -1725,6 +1726,8 @@
 
 	/* Start the module */
 	for (i = 0; i < mod->num_ie_pairs; i++) {
+	    	if (mod->ie_pairs[i].init == NULL)
+		    	continue;
 		ret = mod->ie_pairs[i].init();
 		if (ret != 0) {
 			DEBUGP("%s: init/exit pair init=%p failed: %i\n",

Re: [PATCH 3/3] Allow arbitrary number of init funcs in modules

[Rusty Russell]

In message <20030623191141.31814.qmail@eklektix.com> you write:
> > Feedback is extremely welcome,
> 
> OK...you asked for it.  I found three separate bugs, two of them oopsed the
> system, and the other prevented module unloading.  Did you try it with
> CONFIG_MODULE_UNLOAD? :) You also need to test for null init functions,
> because the module_init/module_exit mode creates them.  Patch appended.

Wow, someone actually tested it!  I do sometimes wonder.

It turns out that I tested an older version with modules, and only
tested this rewrite with in-built code.  Mea culpa.

> Also...some guy once posted (http://lwn.net/Articles/22763/):
> 
> 	I appeciate the series in modernizing modules, but just FYI, I
> 	don't think the old-style init_module/cleanup_module stuff will
> 	break any time soon: there are still a large number of drivers
> 	which use it, and there's not much point making such changes.
> 
> This patch breaks the old init_module/cleanup_module scheme; those
> functions no longer get called.  Was that intentional?

<SIGH> I'd forgotten about that; there are about 100 places where this
technique is still used.  The change would be trivial, but this isn't
2.5.lownum anymore.  Workaround incorporated.

> P.S. Beyond that, I think the patch makes sense :)

Thanks...

> --- 2.5.73-rr/kernel/module.c	Tue Jun 24 02:58:32 2003
> +++ 2.5.73/kernel/module.c	Tue Jun 24 03:00:36 2003
> @@ -617,9 +617,10 @@
>  {
>  	int i, balance = 0;
>  
> -	for (i = 0; i < num_pairs; i++)
> +	for (i = 0; i < num_pairs; i++) {
>  		balance += (pairs->init ? 1 : 0) - (pairs->exit ? 1 : 0);
> -
> +		pairs++;
> +	}
>  	return balance == 0;
>  }
>  

I prefer to use pairs[i].init.  Rest applied untouched.

I'll test and release a new on soon...
Thanks!
Rusty.
--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

Re: [PATCH 3/3] Allow arbitrary number of init funcs in modules

[Rusty Russell]

In message <20030623191141.31814.qmail@eklektix.com> you write:
> > Feedback is extremely welcome,
> 
> OK...you asked for it.  I found three separate bugs, two of them oopsed the

OK, patch applied, ancient-style module init supported (after separate
patch to clean out some cruft) and init-sorting routine fixed too.
Tested on 2.5.73-bk1, test patch included.

For convenience, all patches in one long mail.

Feedback still welcome 8)
Rusty.
--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

Name: Centralize token pasting and generation of unique IDs
Author: Rusty Russell
Status: Tested on 2.5.70-bk13

D: Add __cat(a,b) to implement token pasting to stringify.h.  To
D: generate unique names, __unique_id(stem) is implemented (it'd be
D: nice to have a gcc extension to give a unique identifier).  Change
D: module.h to use them.

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .26569-linux-2.5.70-bk16/include/linux/module.h .26569-linux-2.5.70-bk16.updated/include/linux/module.h
--- .26569-linux-2.5.70-bk16/include/linux/module.h	2003-06-12 09:58:02.000000000 +1000
+++ .26569-linux-2.5.70-bk16.updated/include/linux/module.h	2003-06-12 16:19:16.000000000 +1000
@@ -55,10 +55,8 @@ search_extable(const struct exception_ta
 	       unsigned long value);
 
 #ifdef MODULE
-#define ___module_cat(a,b) __mod_ ## a ## b
-#define __module_cat(a,b) ___module_cat(a,b)
 #define __MODULE_INFO(tag, name, info)					  \
-static const char __module_cat(name,__LINE__)[]				  \
+static const char __unique_id(name)[]					  \
   __attribute__((section(".modinfo"),unused)) = __stringify(tag) "=" info
 
 #define MODULE_GENERIC_TABLE(gtype,name)			\
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .26569-linux-2.5.70-bk16/include/linux/stringify.h .26569-linux-2.5.70-bk16.updated/include/linux/stringify.h
--- .26569-linux-2.5.70-bk16/include/linux/stringify.h	2003-01-02 12:25:36.000000000 +1100
+++ .26569-linux-2.5.70-bk16.updated/include/linux/stringify.h	2003-06-12 16:32:17.000000000 +1000
@@ -9,4 +9,11 @@
 #define __stringify_1(x)	#x
 #define __stringify(x)		__stringify_1(x)
 
+/* Paste two tokens together. */
+#define ___cat(a,b) a ## b
+#define __cat(a,b) ___cat(a,b)
+
+/* Try to give a unique identifier: this comes close, iff used as static. */
+#define __unique_id(stem) \
+	__cat(__cat(__uniq,stem),__cat(__LINE__,KBUILD_BASENAME))
 #endif	/* !__LINUX_STRINGIFY_H */

Name: Delete redundant init_module and cleanup_module prototypes.
Author: Rusty Russell
Status: Trivial

D: A few places pre-declare "int module_init(void);" and "void
D: module_cleanup(void);".  Other than being obsolete, this is
D: unneccessary (it's in init.h anyway).
D: 
D: There are still about 100 places which still use the
D: obsolete-since-2.2 "a function named module_init() magically gets
D: called": this change frees us up implement that via a macro.

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .11903-linux-2.5.73-bk1/drivers/block/paride/pf.c .11903-linux-2.5.73-bk1.updated/drivers/block/paride/pf.c
--- .11903-linux-2.5.73-bk1/drivers/block/paride/pf.c	2003-05-05 12:36:58.000000000 +1000
+++ .11903-linux-2.5.73-bk1.updated/drivers/block/paride/pf.c	2003-06-24 11:43:58.000000000 +1000
@@ -222,9 +222,6 @@ MODULE_PARM(drive3, "1-7i");
 #define ATAPI_READ_10		0x28
 #define ATAPI_WRITE_10		0x2a
 
-#ifdef MODULE
-void cleanup_module(void);
-#endif
 static int pf_open(struct inode *inode, struct file *file);
 static void do_pf_request(request_queue_t * q);
 static int pf_ioctl(struct inode *inode, struct file *file,
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .11903-linux-2.5.73-bk1/drivers/char/istallion.c .11903-linux-2.5.73-bk1.updated/drivers/char/istallion.c
--- .11903-linux-2.5.73-bk1/drivers/char/istallion.c	2003-06-15 11:29:51.000000000 +1000
+++ .11903-linux-2.5.73-bk1.updated/drivers/char/istallion.c	2003-06-24 11:43:58.000000000 +1000
@@ -650,8 +650,6 @@ static unsigned int	stli_baudrates[] = {
  */
 
 #ifdef MODULE
-int		init_module(void);
-void		cleanup_module(void);
 static void	stli_argbrds(void);
 static int	stli_parsebrd(stlconf_t *confp, char **argp);
 
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .11903-linux-2.5.73-bk1/drivers/char/moxa.c .11903-linux-2.5.73-bk1.updated/drivers/char/moxa.c
--- .11903-linux-2.5.73-bk1/drivers/char/moxa.c	2003-06-23 10:52:46.000000000 +1000
+++ .11903-linux-2.5.73-bk1.updated/drivers/char/moxa.c	2003-06-24 11:43:58.000000000 +1000
@@ -216,10 +216,7 @@ static struct timer_list moxaEmptyTimer[
 static struct semaphore moxaBuffSem;
 
 int moxa_init(void);
-#ifdef MODULE
-int init_module(void);
-void cleanup_module(void);
-#endif
+
 /*
  * static functions:
  */
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .11903-linux-2.5.73-bk1/drivers/char/nwbutton.h .11903-linux-2.5.73-bk1.updated/drivers/char/nwbutton.h
--- .11903-linux-2.5.73-bk1/drivers/char/nwbutton.h	2003-05-27 15:02:08.000000000 +1000
+++ .11903-linux-2.5.73-bk1.updated/drivers/char/nwbutton.h	2003-06-24 11:43:58.000000000 +1000
@@ -32,10 +32,6 @@ int button_init (void);
 int button_add_callback (void (*callback) (void), int count);
 int button_del_callback (void (*callback) (void));
 static void button_consume_callbacks (int bpcount);
-#ifdef MODULE
-int init_module (void);
-void cleanup_module (void);
-#endif /* MODULE */
 
 #else /* Not compiling the driver itself */
 
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .11903-linux-2.5.73-bk1/drivers/char/pcxx.c .11903-linux-2.5.73-bk1.updated/drivers/char/pcxx.c
--- .11903-linux-2.5.73-bk1/drivers/char/pcxx.c	2003-06-15 11:29:51.000000000 +1000
+++ .11903-linux-2.5.73-bk1.updated/drivers/char/pcxx.c	2003-06-24 11:50:28.000000000 +1000
@@ -209,17 +209,9 @@ static void cleanup_board_resources(void
 
 #ifdef MODULE
 
-/*
- * pcxe_init() is our init_module():
- */
-#define pcxe_init init_module
-
-void	cleanup_module(void);
-
-
 /*****************************************************************************/
 
-void cleanup_module()
+static void pcxe_cleanup()
 {
 
 	unsigned long	flags;
@@ -240,6 +232,12 @@ void cleanup_module()
 	kfree(digi_channels);
 	restore_flags(flags);
 }
+
+/*
+ * pcxe_init() is our init_module():
+ */
+module_init(pcxe_init);
+module_cleanup(pcxe_cleanup);
 #endif
 
 static inline struct channel *chan(register struct tty_struct *tty)
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .11903-linux-2.5.73-bk1/drivers/char/stallion.c .11903-linux-2.5.73-bk1.updated/drivers/char/stallion.c
--- .11903-linux-2.5.73-bk1/drivers/char/stallion.c	2003-06-15 11:29:52.000000000 +1000
+++ .11903-linux-2.5.73-bk1.updated/drivers/char/stallion.c	2003-06-24 11:43:58.000000000 +1000
@@ -472,8 +472,6 @@ static unsigned int	stl_baudrates[] = {
  */
 
 #ifdef MODULE
-int		init_module(void);
-void		cleanup_module(void);
 static void	stl_argbrds(void);
 static int	stl_parsebrd(stlconf_t *confp, char **argp);
 
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .11903-linux-2.5.73-bk1/drivers/net/wan/sdladrv.c .11903-linux-2.5.73-bk1.updated/drivers/net/wan/sdladrv.c
--- .11903-linux-2.5.73-bk1/drivers/net/wan/sdladrv.c	2003-06-15 11:29:56.000000000 +1000
+++ .11903-linux-2.5.73-bk1.updated/drivers/net/wan/sdladrv.c	2003-06-24 11:43:58.000000000 +1000
@@ -160,10 +160,6 @@
 
 /****** Function Prototypes *************************************************/
 
-/* Module entry points. These are called by the OS and must be public. */
-int init_module (void);
-void cleanup_module (void);
-
 /* Hardware-specific functions */
 static int sdla_detect	(sdlahw_t* hw);
 static int sdla_autodpm	(sdlahw_t* hw);
@@ -325,11 +321,7 @@ static int pci_slot_ar[MAX_S514_CARDS];
  * Context:	process
  */
 
-#ifdef MODULE
-int init_module (void)
-#else
 int sdladrv_init(void)
-#endif
 {
 	int i=0;
 
@@ -354,9 +346,12 @@ int sdladrv_init(void)
  * Module 'remove' entry point.
  * o release all remaining system resources
  */
-void cleanup_module (void)
+static void sdladrv_cleanup(void)
 {
 }
+
+module_init(sdladrv_init);
+module_cleanup(sdladrv_cleanup);
 #endif
 
 /******* Kernel APIs ********************************************************/
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .11903-linux-2.5.73-bk1/drivers/net/wan/sdlamain.c .11903-linux-2.5.73-bk1.updated/drivers/net/wan/sdlamain.c
--- .11903-linux-2.5.73-bk1/drivers/net/wan/sdlamain.c	2003-05-27 15:02:12.000000000 +1000
+++ .11903-linux-2.5.73-bk1.updated/drivers/net/wan/sdlamain.c	2003-06-24 11:43:58.000000000 +1000
@@ -177,10 +177,6 @@ static void dbg_kfree(void * v, int line
 extern void disable_irq(unsigned int);
 extern void enable_irq(unsigned int);
  
-/* Module entry points */
-int init_module (void);
-void cleanup_module (void);
-
 /* WAN link driver entry points */
 static int setup(struct wan_device* wandev, wandev_conf_t* conf);
 static int shutdown(struct wan_device* wandev);
@@ -246,11 +242,7 @@ static int wanpipe_bh_critical=0;
  * Context:	process
  */
  
-#ifdef MODULE
-int init_module (void)
-#else
 int wanpipe_init(void)
-#endif
 {
 	int cnt, err = 0;
 
@@ -313,7 +305,7 @@ int wanpipe_init(void)
  * o unregister all adapters from the WAN router
  * o release all remaining system resources
  */
-void cleanup_module (void)
+static void wanpipe_cleanup(void)
 {
 	int i;
 
@@ -329,6 +321,8 @@ void cleanup_module (void)
 	printk(KERN_INFO "\nwanpipe: WANPIPE Modules Unloaded.\n");
 }
 
+module_init(wanpipe_init);
+module_exit(wanpipe_cleanup);
 #endif
 
 /******* WAN Device Driver Entry Points *************************************/

Name: Eliminate Unused Functions
Author: Rusty Russell
Status: Tested on 2.5.70-bk16

D: GCC 3.3 has the ability to eliminate unused static functions.  This includes
D: code like this:
D:
D: static int unusedfunc(void) { ... };
D: int otherfunc(void)
D: {
D:         (void)unusedfunc;
D: ...
D: 
D: This means that macros can suppress the "unused" warning on functions
D: without preventing the function elimination.  This should allow us to
D: remove a number of #ifdefs around unused functions.
D:
D: Unfortunately, this elimination is only performed if
D: -finline-functions is used.  In order to prevent GCC automatically
D: inlining anything, we also specify "--param max-inline-insns-auto=0".
D:
D: Earlier compilers don't understand this parameter, so we test for
D: it at build time.
D:
D: Results:
D:   gcc 3.3 without patch:
D:       -rwxrwxr-x    1 rusty    rusty     5115166 Jun 13 09:17 vmlinux
D:   gcc 3.3 with patch:
D:       -rwxrwxr-x    1 rusty    rusty     5115166 Jun 13 09:58 vmlinux
D:   gcc 3.3 without patch (small unused function added):
D:       -rwxrwxr-x    1 rusty    rusty     5115195 Jun 13 10:14 vmlinux
D:   gcc 3.3 with patch (small unused function added):
D:       -rwxrwxr-x    1 rusty    rusty     5115166 Jun 13 10:15 vmlinux

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal working-2.5.70-bk16-check_region/Makefile working-2.5.70-bk16-check_region-inline/Makefile
--- working-2.5.70-bk16-check_region/Makefile	2003-06-12 09:57:39.000000000 +1000
+++ working-2.5.70-bk16-check_region-inline/Makefile	2003-06-12 21:34:40.000000000 +1000
@@ -213,10 +213,12 @@ CFLAGS_KERNEL	=
 AFLAGS_KERNEL	=
 
 NOSTDINC_FLAGS  = -nostdinc -iwithprefix include
+# Needs gcc 3.3 or above to understand max-inline-insns-auto.
+INLINE_OPTS	:= $(shell $(CC) -o /non/existent/file -c --param max-inline-insns-auto=0 -xc /dev/null 2>&1 | grep /non/existent/file >/dev/null && echo -finline-functions --param max-inline-insns-auto=0)
 
 CPPFLAGS	:= -D__KERNEL__ -Iinclude
 CFLAGS 		:= $(CPPFLAGS) -Wall -Wstrict-prototypes -Wno-trigraphs -O2 \
-	  	   -fno-strict-aliasing -fno-common
+	  	   $(INLINE_OPTS) -fno-strict-aliasing -fno-common
 AFLAGS		:= -D__ASSEMBLY__ $(CPPFLAGS)
 
 export	VERSION PATCHLEVEL SUBLEVEL EXTRAVERSION KERNELRELEASE ARCH \

Name: Test Arbitrary Number of Init and Exit Functions
Author: Rusty Russell
Status: Tested on 2.5.73-bk1
Depends: Module/init_exit.patch.gz

D: Test code for module_init_exit: adds example helpers for proc_net
D: and netfilter, and uses them in netfilter.  Also adds module foo
D: which uses really old-style init.

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15095-linux-2.5.73-bk1/include/linux/netfilter.h .15095-linux-2.5.73-bk1.updated/include/linux/netfilter.h
--- .15095-linux-2.5.73-bk1/include/linux/netfilter.h	2003-05-05 12:37:12.000000000 +1000
+++ .15095-linux-2.5.73-bk1.updated/include/linux/netfilter.h	2003-06-24 12:19:07.000000000 +1000
@@ -9,6 +9,8 @@
 #include <linux/if.h>
 #include <linux/wait.h>
 #include <linux/list.h>
+#include <linux/stringify.h>
+#include <linux/module.h>
 #endif
 
 /* Responses from hook functions. */
@@ -91,6 +93,21 @@ struct nf_info
 int nf_register_hook(struct nf_hook_ops *reg);
 void nf_unregister_hook(struct nf_hook_ops *reg);
 
+/* Automatically register/unregister */
+#define module_nf_hook(_prio, _hookfn, _pf, _hooknum, _hookprio)	     \
+ static struct nf_hook_ops __cat(nf_hook, _hookfn)			     \
+ = { .hook=_hookfn, .owner=THIS_MODULE, .pf=_pf, .hooknum=_hooknum,	     \
+     .priority=_hookprio }; 						     \
+ static int __init __cat(nfh_reg, _hookfn)(void)			     \
+ {									     \
+ 	return nf_register_hook(&__cat(nf_hook, _hookfn));		     \
+ }									     \
+ static void __init __cat(nfh_unreg, _hookfn)(void)			     \
+ {									     \
+ 	nf_unregister_hook(&__cat(nf_hook, _hookfn));			     \
+ }									     \
+ module_init_exit(_prio, __cat(nfh_reg, _hookfn), __cat(nfh_unreg, _hookfn))
+
 /* Functions to register get/setsockopt ranges (non-inclusive).  You
    need to check permissions yourself! */
 int nf_register_sockopt(struct nf_sockopt_ops *reg);
@@ -163,6 +180,10 @@ extern void nf_invalidate_cache(int pf);
 
 #else /* !CONFIG_NETFILTER */
 #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
+
+/* Just check type and suppress unused message. */
+#define module_nf_hook(prio, hookfn, pf, hooknum, hookprio)	\
+static inline nf_hookfn *__unique_id(hookfn) { return hookfn; }
 #endif /*CONFIG_NETFILTER*/
 
 #endif /*__KERNEL__*/
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15095-linux-2.5.73-bk1/include/linux/proc_fs.h .15095-linux-2.5.73-bk1.updated/include/linux/proc_fs.h
--- .15095-linux-2.5.73-bk1/include/linux/proc_fs.h	2003-06-15 11:30:09.000000000 +1000
+++ .15095-linux-2.5.73-bk1.updated/include/linux/proc_fs.h	2003-06-24 12:19:07.000000000 +1000
@@ -4,6 +4,7 @@
 #include <linux/config.h>
 #include <linux/slab.h>
 #include <linux/fs.h>
+#include <linux/init.h>
 #include <asm/atomic.h>
 
 /*
@@ -191,6 +192,20 @@ static inline void proc_net_remove(const
 extern void kclist_add(struct kcore_list *, void *, size_t);
 extern struct kcore_list *kclist_del(void *);
 
+#define module_proc_net(prio, name, fn)					     \
+static int __cat(_proc_net_init,fn)(void)				     \
+{									     \
+	struct proc_dir_entry *proc = proc_net_create(name, 0, fn);	     \
+	if (!proc)							     \
+		return -EINVAL;						     \
+	proc->owner = THIS_MODULE;					     \
+	return 0;							     \
+}									     \
+static void __cat(_proc_net_exit,fn)(void)				     \
+{									     \
+	proc_net_remove(name);						     \
+}									     \
+module_init_exit(prio, __cat(_proc_net_init,fn), __cat(_proc_net_exit,fn))
 #else
 
 #define proc_root_driver NULL
@@ -236,6 +251,10 @@ static inline struct kcore_list * kclist
 	return NULL;
 }
 
+/* Check type and stop gcc from complaining about unused function, but
+ * allow gcc 3.3+ to discard it. */
+#define module_proc_net(prio, name, fn)     \
+static inline get_info_t *__unique_id(test_fntype)(void) { return fn; }
 #endif /* CONFIG_PROC_FS */
 
 struct proc_inode {
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15095-linux-2.5.73-bk1/net/ipv4/Makefile .15095-linux-2.5.73-bk1.updated/net/ipv4/Makefile
--- .15095-linux-2.5.73-bk1/net/ipv4/Makefile	2003-06-15 11:30:12.000000000 +1000
+++ .15095-linux-2.5.73-bk1.updated/net/ipv4/Makefile	2003-06-24 12:19:07.000000000 +1000
@@ -23,3 +23,4 @@ obj-$(CONFIG_IP_PNP) += ipconfig.o
 obj-$(CONFIG_NETFILTER)	+= netfilter/
 
 obj-y += xfrm4_policy.o xfrm4_state.o xfrm4_input.o xfrm4_tunnel.o
+obj-m += foo.o
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15095-linux-2.5.73-bk1/net/ipv4/foo.c .15095-linux-2.5.73-bk1.updated/net/ipv4/foo.c
--- .15095-linux-2.5.73-bk1/net/ipv4/foo.c	1970-01-01 10:00:00.000000000 +1000
+++ .15095-linux-2.5.73-bk1.updated/net/ipv4/foo.c	2003-06-24 16:45:38.000000000 +1000
@@ -0,0 +1,42 @@
+#include <linux/types.h>
+#include <linux/ip.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/init.h>
+#include <linux/moduleparam.h>
+
+static int fail_hook;
+module_param(fail_hook, int, 0);
+
+#define HOOK(n) 				\
+static int init##n(void)			\
+{						\
+	printk("foo: init %u\n", n);		\
+	if (n == fail_hook)			\
+		return -EINVAL;			\
+	return 0;				\
+}						\
+static void fini##n(void)			\
+{						\
+	printk("foo: fini %u\n", n);		\
+}						\
+module_init_exit(-n, init##n, fini##n)
+
+HOOK(5);
+HOOK(1);
+HOOK(2);
+HOOK(3);
+HOOK(4);
+HOOK(6);
+
+/* Old-style... */
+int init_module(void)
+{
+	printk("foo: init module\n");
+	return 0;
+}
+
+void cleanup_module(void)
+{
+	printk("foo: cleanup module\n");
+}
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15095-linux-2.5.73-bk1/net/ipv4/netfilter/ip_conntrack_standalone.c .15095-linux-2.5.73-bk1.updated/net/ipv4/netfilter/ip_conntrack_standalone.c
--- .15095-linux-2.5.73-bk1/net/ipv4/netfilter/ip_conntrack_standalone.c	2003-05-05 12:37:14.000000000 +1000
+++ .15095-linux-2.5.73-bk1.updated/net/ipv4/netfilter/ip_conntrack_standalone.c	2003-06-24 12:19:07.000000000 +1000
@@ -223,95 +223,6 @@ static unsigned int ip_conntrack_local(u
 	return ip_conntrack_in(hooknum, pskb, in, out, okfn);
 }
 
-/* Connection tracking may drop packets, but never alters them, so
-   make it the first hook. */
-static struct nf_hook_ops ip_conntrack_in_ops = {
-	.hook		= ip_conntrack_in,
-	.owner		= THIS_MODULE,
-	.pf		= PF_INET,
-	.hooknum	= NF_IP_PRE_ROUTING,
-	.priority	= NF_IP_PRI_CONNTRACK,
-};
-
-static struct nf_hook_ops ip_conntrack_local_out_ops = {
-	.hook		= ip_conntrack_local,
-	.owner		= THIS_MODULE,
-	.pf		= PF_INET,
-	.hooknum	= NF_IP_LOCAL_OUT,
-	.priority	= NF_IP_PRI_CONNTRACK,
-};
-
-/* Refragmenter; last chance. */
-static struct nf_hook_ops ip_conntrack_out_ops = {
-	.hook		= ip_refrag,
-	.owner		= THIS_MODULE,
-	.pf		= PF_INET,
-	.hooknum	= NF_IP_POST_ROUTING,
-	.priority	= NF_IP_PRI_LAST,
-};
-
-static struct nf_hook_ops ip_conntrack_local_in_ops = {
-	.hook		= ip_confirm,
-	.owner		= THIS_MODULE,
-	.pf		= PF_INET,
-	.hooknum	= NF_IP_LOCAL_IN,
-	.priority	= NF_IP_PRI_LAST-1,
-};
-
-static int init_or_cleanup(int init)
-{
-	struct proc_dir_entry *proc;
-	int ret = 0;
-
-	if (!init) goto cleanup;
-
-	ret = ip_conntrack_init();
-	if (ret < 0)
-		goto cleanup_nothing;
-
-	proc = proc_net_create("ip_conntrack",0,list_conntracks);
-	if (!proc) goto cleanup_init;
-	proc->owner = THIS_MODULE;
-
-	ret = nf_register_hook(&ip_conntrack_in_ops);
-	if (ret < 0) {
-		printk("ip_conntrack: can't register pre-routing hook.\n");
-		goto cleanup_proc;
-	}
-	ret = nf_register_hook(&ip_conntrack_local_out_ops);
-	if (ret < 0) {
-		printk("ip_conntrack: can't register local out hook.\n");
-		goto cleanup_inops;
-	}
-	ret = nf_register_hook(&ip_conntrack_out_ops);
-	if (ret < 0) {
-		printk("ip_conntrack: can't register post-routing hook.\n");
-		goto cleanup_inandlocalops;
-	}
-	ret = nf_register_hook(&ip_conntrack_local_in_ops);
-	if (ret < 0) {
-		printk("ip_conntrack: can't register local in hook.\n");
-		goto cleanup_inoutandlocalops;
-	}
-
-	return ret;
-
- cleanup:
-	nf_unregister_hook(&ip_conntrack_local_in_ops);
- cleanup_inoutandlocalops:
-	nf_unregister_hook(&ip_conntrack_out_ops);
- cleanup_inandlocalops:
-	nf_unregister_hook(&ip_conntrack_local_out_ops);
- cleanup_inops:
-	nf_unregister_hook(&ip_conntrack_in_ops);
- cleanup_proc:
-	proc_net_remove("ip_conntrack");
- cleanup_init:
-	ip_conntrack_cleanup();
- cleanup_nothing:
-	return ret;
-}
-
 /* FIXME: Allow NULL functions and sub in pointers to generic for
    them. --RR */
 int ip_conntrack_protocol_register(struct ip_conntrack_protocol *proto)
@@ -351,25 +262,26 @@ void ip_conntrack_protocol_unregister(st
 	ip_ct_selective_cleanup(kill_proto, &proto->proto);
 }
 
-static int __init init(void)
-{
-	return init_or_cleanup(1);
-}
-
-static void __exit fini(void)
-{
-	init_or_cleanup(0);
-}
-
-module_init(init);
-module_exit(fini);
-
 /* Some modules need us, but don't depend directly on any symbol.
    They should call this. */
 void need_ip_conntrack(void)
 {
 }
 
+module_init_exit(-1, ip_conntrack_init, ip_conntrack_cleanup);
+module_proc_net(0, "ip_conntrack", list_conntracks);
+
+/* Connection tracking may drop packets, but never alters them, so
+   make it the first hook. */
+module_nf_hook(0, ip_conntrack_in, PF_INET, NF_IP_PRE_ROUTING,
+	       NF_IP_PRI_CONNTRACK);
+module_nf_hook(0, ip_conntrack_local, PF_INET, NF_IP_LOCAL_OUT,
+	       NF_IP_PRI_CONNTRACK);
+module_nf_hook(0, ip_confirm, PF_INET, NF_IP_LOCAL_IN, NF_IP_PRI_LAST-1);
+
+/* Refragmenter; last chance. */
+module_nf_hook(0, ip_refrag, PF_INET, NF_IP_POST_ROUTING, NF_IP_PRI_LAST);
+
 EXPORT_SYMBOL(ip_conntrack_protocol_register);
 EXPORT_SYMBOL(ip_conntrack_protocol_unregister);
 EXPORT_SYMBOL(invert_tuplepr);
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .15095-linux-2.5.73-bk1/net/ipv4/netfilter/ip_tables.c .15095-linux-2.5.73-bk1.updated/net/ipv4/netfilter/ip_tables.c
--- .15095-linux-2.5.73-bk1/net/ipv4/netfilter/ip_tables.c	2003-05-27 15:02:26.000000000 +1000
+++ .15095-linux-2.5.73-bk1.updated/net/ipv4/netfilter/ip_tables.c	2003-06-24 12:19:07.000000000 +1000
@@ -1702,7 +1702,6 @@ static struct ipt_match icmp_matchstruct
 	.checkentry	= &icmp_checkentry,
 };
 
-#ifdef CONFIG_PROC_FS
 static inline int print_name(const struct ipt_table *t,
 			     off_t start_offset, char *buffer, int length,
 			     off_t *pos, unsigned int *count)
@@ -1737,13 +1736,13 @@ static int ipt_get_tables(char *buffer, 
 	*start=(char *)((unsigned long)count-offset);
 	return pos;
 }
-#endif /*CONFIG_PROC_FS*/
+
+module_proc_net(-1, "ip_tables_names", ipt_get_tables);
 
 static int __init init(void)
 {
 	int ret;
 
-	/* Noone else will be downing sem now, so we won't sleep */
 	down(&ipt_mutex);
 	list_append(&ipt_target, &ipt_standard_target);
 	list_append(&ipt_target, &ipt_error_target);
@@ -1759,19 +1758,6 @@ static int __init init(void)
 		return ret;
 	}
 
-#ifdef CONFIG_PROC_FS
-	{
-	struct proc_dir_entry *proc;
-
-	proc = proc_net_create("ip_tables_names", 0, ipt_get_tables);
-	if (!proc) {
-		nf_unregister_sockopt(&ipt_sockopts);
-		return -ENOMEM;
-	}
-	proc->owner = THIS_MODULE;
-	}
-#endif
-
 	printk("ip_tables: (C) 2000-2002 Netfilter core team\n");
 	return 0;
 }
@@ -1779,9 +1765,6 @@ static int __init init(void)
 static void __exit fini(void)
 {
 	nf_unregister_sockopt(&ipt_sockopts);
-#ifdef CONFIG_PROC_FS
-	proc_net_remove("ip_tables_names");
-#endif
 }
 
 EXPORT_SYMBOL(ipt_register_table);

Re: [PATCH 3/3] Allow arbitrary number of init funcs in modules

[Roman Zippel]

Hi,

On Mon, 23 Jun 2003, Rusty Russell wrote:

> D: One longstanding complaint is that modules can only have one
> D: module_init, and one module_exit (builtin code can have multiple
> D: __initcall however).  This means, for example, that it is not
> D: possible to write a "module_proc_entry(name, readfn)" function
> D: which can be used like so:
> D: 
> D:   module_init(myinitfn);
> D:   module_cleanup(myinitfn);
> D:   module_proc_entry("some/path/foo", read_foo);

What happens if a module is compiled into the kernel and one of the init 
functions fails?

bye, Roman

Re: [PATCH 3/3] Allow arbitrary number of init funcs in modules

[Horst von Brand]

corbet@lwn.net (Jonathan Corbet) said:
> --- 2.5.73-rr/kernel/module.c	Tue Jun 24 02:58:32 2003
> +++ 2.5.73/kernel/module.c	Tue Jun 24 03:00:36 2003
> @@ -617,9 +617,10 @@
>  {
>  	int i, balance = 0;
>  
> -	for (i = 0; i < num_pairs; i++)
> +	for (i = 0; i < num_pairs; i++) {
>  		balance += (pairs->init ? 1 : 0) - (pairs->exit ? 1 : 0);
> -
> +		pairs++;
> +	}

Hummm... as you are essentially counting off pairs, isn't there a way of
detecting end-of-pairs, i.e. along the line (last points to NULL):

        for(pairs = start_of_pairs; *pairs; pairs++)
             ....

or just:

        for(i = 0; i < num_pairs; i++)
	       balance += (pairs[i].init ? 1 : 0) - (pairs[i].exit ? 1 : 0);

(as added bonus doesn't screw up variable pairs' value), or even (same as
yours above but marginally clearer IMEHO):

        for (i = 0; i < num_pairs; i++, pairs++)
              .....
-- 
Dr. Horst H. von Brand                   User #22616 counter.li.org
Departamento de Informatica                     Fono: +56 32 654431
Universidad Tecnica Federico Santa Maria              +56 32 654239
Casilla 110-V, Valparaiso, Chile                Fax:  +56 32 797513

Re: [PATCH 3/3] Allow arbitrary number of init funcs in modules

[Rusty Russell]

In message <Pine.LNX.4.44.0306241851550.11817-100000@serv> you write:
> Hi,
> 
> On Mon, 23 Jun 2003, Rusty Russell wrote:
> 
> > D: One longstanding complaint is that modules can only have one
> > D: module_init, and one module_exit (builtin code can have multiple
> > D: __initcall however).  This means, for example, that it is not
> > D: possible to write a "module_proc_entry(name, readfn)" function
> > D: which can be used like so:
> > D: 
> > D:   module_init(myinitfn);
> > D:   module_cleanup(myinitfn);
> > D:   module_proc_entry("some/path/foo", read_foo);
> 
> What happens if a module is compiled into the kernel and one of the init 
> functions fails?

We ignore the failure, as we do with initcalls at the moment.  I
wasn't really intending to deprecate the existing mechanisms: this is
simple at least 8)

Hmm, were you thinking of grouping by KBUILD_BASENAME?  Can you think
of a case where that would be nicer to use?

Thanks!
Rusty.
--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

Re: [PATCH 3/3] Allow arbitrary number of init funcs in modules

[Roman Zippel]

Hi,

On Wed, 25 Jun 2003, Rusty Russell wrote:

> > What happens if a module is compiled into the kernel and one of the init 
> > functions fails?
> 
> We ignore the failure, as we do with initcalls at the moment.  I
> wasn't really intending to deprecate the existing mechanisms: this is
> simple at least 8)
> 
> Hmm, were you thinking of grouping by KBUILD_BASENAME?  Can you think
> of a case where that would be nicer to use?

It's not a case of nicer to use, it's about consistent behaviour 
independent of how the module is linked into the kernel.
I'm really not convinced this feature is a good idea until the module 
initialization races are not at least basically solved.

bye, Roman