typesafe: Convert stop_machine and callers Simple statement expression with a temporary variable does the typechecking for us: that the stop_machine callback matches the data type. Signed-off-by: Rusty Russell --- drivers/char/hw_random/intel-rng.c | 3 - include/linux/stop_machine.h | 16 ++++-- kernel/module.c | 10 +--- kernel/stop_machine.c | 89 ++++++++++++++++++++++++++++++++++++- 4 files changed, 103 insertions(+), 15 deletions(-) diff -r e279190b7b43 drivers/char/hw_random/intel-rng.c --- a/drivers/char/hw_random/intel-rng.c Mon Jan 21 14:42:54 2008 +1100 +++ b/drivers/char/hw_random/intel-rng.c Mon Jan 21 15:04:00 2008 +1100 @@ -227,9 +227,8 @@ struct intel_rng_hw { u8 fwh_dec_en1_val; }; -static int __init intel_rng_hw_init(void *_intel_rng_hw) +static int __init intel_rng_hw_init(struct intel_rng_hw *intel_rng_hw) { - struct intel_rng_hw *intel_rng_hw = _intel_rng_hw; u8 mfc, dvc; /* interrupts disabled in stop_machine_run call */ diff -r e279190b7b43 include/linux/stop_machine.h --- a/include/linux/stop_machine.h Mon Jan 21 14:42:54 2008 +1100 +++ b/include/linux/stop_machine.h Mon Jan 21 15:04:00 2008 +1100 @@ -5,9 +5,9 @@ (and more). So the "read" side to such a lock is anything which diables preeempt. */ #include +#include #include -#if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP) /** * stop_machine_run: freeze the machine on all CPUs and run this function * @fn: the function to run @@ -21,7 +21,15 @@ * * This can be thought of as a very heavy write lock, equivalent to * grabbing every spinlock in the kernel. */ -int stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu); +#define stop_machine_run(fn, data, cpu) \ +stop_machine_run_notype(typesafe_function((fn), int(*)(unsigned long), \ + int(*)(typeof(data)), \ + int(*)(void *), (data)), \ + typesafe_arg((fn), int(*)(unsigned long), (data)), \ + (cpu)) + +#if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP) +int stop_machine_run_notype(int (*fn)(void *), void *data, unsigned int cpu); /** * __stop_machine_run: freeze the machine on all CPUs and run this function @@ -38,8 +46,8 @@ struct task_struct *__stop_machine_run(i #else -static inline int stop_machine_run(int (*fn)(void *), void *data, - unsigned int cpu) +static inline int stop_machine_run_notype(int (*fn)(void *), void *data, + unsigned int cpu) { int ret; local_irq_disable(); diff -r e279190b7b43 kernel/module.c --- a/kernel/module.c Mon Jan 21 14:42:54 2008 +1100 +++ b/kernel/module.c Mon Jan 21 15:04:00 2008 +1100 @@ -623,10 +623,8 @@ struct stopref }; /* Whole machine is stopped with interrupts off when this runs. */ -static int __try_stop_module(void *_sref) +static int __try_stop_module(struct stopref *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 (!(*sref->forced = try_force_unload(sref->flags))) @@ -1305,9 +1303,8 @@ static void mod_kobject_remove(struct mo * link the module with the whole machine is stopped with interrupts off * - this defends against kallsyms not taking locks */ -static int __link_module(void *_mod) +static int __link_module(struct module *mod) { - struct module *mod = _mod; list_add(&mod->list, &modules); return 0; } @@ -1316,9 +1313,8 @@ static int __link_module(void *_mod) * unlink the module with the whole machine is stopped with interrupts off * - this defends against kallsyms not taking locks */ -static int __unlink_module(void *_mod) +static int __unlink_module(struct module *mod) { - struct module *mod = _mod; list_del(&mod->list); return 0; } diff -r e279190b7b43 kernel/stop_machine.c --- a/kernel/stop_machine.c Mon Jan 21 14:42:54 2008 +1100 +++ b/kernel/stop_machine.c Mon Jan 21 15:04:00 2008 +1100 @@ -197,7 +197,7 @@ struct task_struct *__stop_machine_run(i return p; } -int stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu) +int stop_machine_run_notype(int (*fn)(void *), void *data, unsigned int cpu) { struct task_struct *p; int ret; @@ -213,4 +213,89 @@ int stop_machine_run(int (*fn)(void *), return ret; } -EXPORT_SYMBOL_GPL(stop_machine_run); +EXPORT_SYMBOL_GPL(stop_machine_run_notype); + +#if 0 /* Compile test */ +int testfn_voidp(void *); +int testfn_charp(char *); +int testfn_char(char); +int testfn_ulong(unsigned long); + +void test(void) +{ + char c; + unsigned long ul; + void *p; + struct { void *p; } s; + + /* + * Should work + */ + /* void * compatible with any pointer. */ + stop_machine_run(testfn_voidp, NULL, 0); + stop_machine_run(testfn_voidp, p, 0); + stop_machine_run(testfn_voidp, &c, 0); + stop_machine_run(testfn_voidp, &ul, 0); + + /* NULL callbacks compatible with any pointer. */ + stop_machine_run(NULL, NULL, 0); + stop_machine_run(NULL, p, 0); + stop_machine_run(NULL, &c, 0); + stop_machine_run(NULL, &ul, 0); + + /* Char * match. */ + stop_machine_run(testfn_charp, &c, 0); + + /* ulong can take any int or long. */ + stop_machine_run(testfn_ulong, c, 0); + stop_machine_run(testfn_ulong, ul, 0); + + /* + * It would be nice if these worked, but they don't (void * arg). + */ + stop_machine_run(testfn_charp, NULL, 0); + stop_machine_run(testfn_charp, p, 0); + stop_machine_run(testfn_ulong, NULL, 0); + stop_machine_run(testfn_ulong, p, 0); + + /* + * Should complain. + */ + + /* void * incompatible with non-pointers. */ + stop_machine_run(testfn_voidp, c, 0); + stop_machine_run(testfn_voidp, ul, 0); + stop_machine_run(testfn_voidp, s, 0); + + /* NULL callbacks incompatible with non-pointers. */ + stop_machine_run(NULL, c, 0); + stop_machine_run(NULL, ul, 0); + stop_machine_run(NULL, s, 0); + + /* char * function and unsigned long */ + stop_machine_run(testfn_charp, &ul, 0); + + /* char * incompatible with non-pointers */ + stop_machine_run(testfn_charp, c, 0); + stop_machine_run(testfn_charp, ul, 0); + stop_machine_run(testfn_charp, s, 0); + + /* A char function simply can't work as a callback. */ + stop_machine_run(testfn_char, NULL, 0); + stop_machine_run(testfn_char, p, 0); + stop_machine_run(testfn_char, &c, 0); + stop_machine_run(testfn_char, &ul, 0); + stop_machine_run(testfn_char, c, 0); + stop_machine_run(testfn_char, ul, 0); + stop_machine_run(testfn_char, s, 0); + + /* unsigned long function and char * */ + stop_machine_run(testfn_ulong, &c, 0); + + /* unsigned long function and unsigned long * */ + stop_machine_run(testfn_ulong, &ul, 0); + + /* unsigned long function and struct. */ + stop_machine_run(testfn_ulong, s, 0); +} +#endif