The patch titled modules: warn about suspicious return values from module's ->init() hook has been added to the -mm tree. Its filename is modules-warn-about-suspicious-return-values-from-modules-init-hook.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: modules: warn about suspicious return values from module's ->init() hook From: Alexey Dobriyan <adobriyan@xxxxxxxxx> Return value convention of module's init functions is 0/-E. Sometimes, e.g. during forward-porting mistakes happen and buggy module created, where result of comparison "workqueue != NULL" is propagated all the way up to sys_init_module. What happens is that some other module created workqueue in question, our module created it again and module was successfully loaded. Or it could be some other bug. Let's make such mistakes much more visible. In retrospective, such messages would noticeably shorten some of my head-scratching sessions. Note, that dump_stack() is just a way to get attention from user. Sample message: sys_init_module: 'foo'->init suspiciously returned 1, it should follow 0/-E convention sys_init_module: loading module anyway... Pid: 4223, comm: modprobe Not tainted 2.6.24-25f666300625d894ebe04bac2b4b3aadb907c861 #5 Call Trace: [<ffffffff80254b05>] sys_init_module+0xe5/0x1d0 [<ffffffff8020b39b>] system_call_after_swapgs+0x7b/0x80 Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx> Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/module.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff -puN kernel/module.c~modules-warn-about-suspicious-return-values-from-modules-init-hook kernel/module.c --- a/kernel/module.c~modules-warn-about-suspicious-return-values-from-modules-init-hook +++ a/kernel/module.c @@ -2184,6 +2184,14 @@ sys_init_module(void __user *umod, wake_up(&module_wq); return ret; } + if (ret > 0) { + printk(KERN_WARNING "%s: '%s'->init suspiciously returned %d, " + "it should follow 0/-E convention\n" + KERN_WARNING "%s: loading module anyway...\n", + __func__, mod->name, ret, + __func__); + dump_stack(); + } /* Now it's a first class citizen! */ mutex_lock(&module_mutex); _ Patches currently in -mm which might be from adobriyan@xxxxxxxxx are origin.patch modules-warn-about-suspicious-return-values-from-modules-init-hook.patch - To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html