From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f69.google.com (mail-pg0-f69.google.com [74.125.83.69]) by kanga.kvack.org (Postfix) with ESMTP id 0F02D280284 for ; Fri, 5 Jan 2018 16:38:33 -0500 (EST) Received: by mail-pg0-f69.google.com with SMTP id n1so2899142pgv.14 for ; Fri, 05 Jan 2018 13:38:33 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id p81sor1964700pfj.30.2018.01.05.13.38.31 for (Google Transport Security); Fri, 05 Jan 2018 13:38:31 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20180105094112.2690475-1-arnd@arndb.de> References: <20180105094112.2690475-1-arnd@arndb.de> From: Dmitry Vyukov Date: Fri, 5 Jan 2018 22:38:10 +0100 Message-ID: Subject: Re: [PATCH] kasan: add declarations for internal functions Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: Arnd Bergmann Cc: Andrew Morton , Andrey Ryabinin , Alexander Potapenko , Stephen Rothwell , Andrey Konovalov , kasan-dev , Linux-MM , LKML On Fri, Jan 5, 2018 at 10:40 AM, Arnd Bergmann wrote: > A patch got merged that made newly added functions static, leading > to a warning about unused functions as well as a link error when > they are actually used: > > mm/kasan/kasan.c:780:7: error: '__asan_set_shadow_f8' defined but not used [-Werror=unused-function] > mm/kasan/kasan.c:791:8: note: in expansion of macro 'DEFINE_ASAN_SET_SHADOW' > mm/kasan/kasan.c:780:7: error: '__asan_set_shadow_f5' defined but not used [-Werror=unused-function] > > It turns out the underlying problem is that a lot of the internal > interfaces of the kasan implementation are only ever called from > code generated by the compiler. These don't need any declarations > to work fine, but cause warnings both with sparse and with 'make W=1': > > mm/kasan/kasan.c:695:1: warning: symbol '__asan_load1' was not declared. Should it be static? > mm/kasan/kasan.c:695:1: warning: symbol '__asan_store1' was not declared. Should it be static? > mm/kasan/kasan.c:696:1: warning: symbol '__asan_load2' was not declared. Should it be static? > mm/kasan/kasan.c:696:1: warning: symbol '__asan_store2' was not declared. Should it be static? > mm/kasan/kasan.c:697:1: warning: symbol '__asan_load4' was not declared. Should it be static? > > This removes the bogus 'static' annotation and adds declarations > for all affected interfaces. > > Fixes: mmotm ("kasan: __asan_set_shadow_00 can be static") > Signed-off-by: Arnd Bergmann > --- > mm/kasan/kasan.c | 12 ++++++------ > mm/kasan/kasan.h | 44 ++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 50 insertions(+), 6 deletions(-) > > diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c > index 83a11e7e3700..3fb497d4fbf8 100644 > --- a/mm/kasan/kasan.c > +++ b/mm/kasan/kasan.c > @@ -783,12 +783,12 @@ EXPORT_SYMBOL(__asan_allocas_unpoison); > } \ > EXPORT_SYMBOL(__asan_set_shadow_##byte) > > -static DEFINE_ASAN_SET_SHADOW(00); > -static DEFINE_ASAN_SET_SHADOW(f1); > -static DEFINE_ASAN_SET_SHADOW(f2); > -static DEFINE_ASAN_SET_SHADOW(f3); > -static DEFINE_ASAN_SET_SHADOW(f5); > -static DEFINE_ASAN_SET_SHADOW(f8); > +DEFINE_ASAN_SET_SHADOW(00); > +DEFINE_ASAN_SET_SHADOW(f1); > +DEFINE_ASAN_SET_SHADOW(f2); > +DEFINE_ASAN_SET_SHADOW(f3); > +DEFINE_ASAN_SET_SHADOW(f5); > +DEFINE_ASAN_SET_SHADOW(f8); > > #ifdef CONFIG_MEMORY_HOTPLUG > static int __meminit kasan_mem_notifier(struct notifier_block *nb, > diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h > index 2792de927fcd..c12dcfde2ebd 100644 > --- a/mm/kasan/kasan.h > +++ b/mm/kasan/kasan.h > @@ -120,4 +120,48 @@ static inline void quarantine_reduce(void) { } > static inline void quarantine_remove_cache(struct kmem_cache *cache) { } > #endif > > +/* > + * Exported functions for interfaces called from assembly or from generated > + * code. Declarations here to avoid warning about missing declarations. > + */ > +asmlinkage void kasan_unpoison_task_stack_below(const void *watermark); > +void __asan_register_globals(struct kasan_global *globals, size_t size); > +void __asan_unregister_globals(struct kasan_global *globals, size_t size); > +void __asan_loadN(unsigned long addr, size_t size); > +void __asan_storeN(unsigned long addr, size_t size); > +void __asan_handle_no_return(void); > +void __asan_poison_stack_memory(const void *addr, size_t size); > +void __asan_unpoison_stack_memory(const void *addr, size_t size); > +void __asan_alloca_poison(unsigned long addr, size_t size); > +void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom); > + > +void __asan_load1(unsigned long addr); > +void __asan_store1(unsigned long addr); > +void __asan_load2(unsigned long addr); > +void __asan_store2(unsigned long addr); > +void __asan_load4(unsigned long addr); > +void __asan_store4(unsigned long addr); > +void __asan_load8(unsigned long addr); > +void __asan_store8(unsigned long addr); > +void __asan_load16(unsigned long addr); > +void __asan_store16(unsigned long addr); > + > +void __asan_load1_noabort(unsigned long addr); > +void __asan_store1_noabort(unsigned long addr); > +void __asan_load2_noabort(unsigned long addr); > +void __asan_store2_noabort(unsigned long addr); > +void __asan_load4_noabort(unsigned long addr); > +void __asan_store4_noabort(unsigned long addr); > +void __asan_load8_noabort(unsigned long addr); > +void __asan_store8_noabort(unsigned long addr); > +void __asan_load16_noabort(unsigned long addr); > +void __asan_store16_noabort(unsigned long addr); > + > +void __asan_set_shadow_00(const void *addr, size_t size); > +void __asan_set_shadow_f1(const void *addr, size_t size); > +void __asan_set_shadow_f2(const void *addr, size_t size); > +void __asan_set_shadow_f3(const void *addr, size_t size); > +void __asan_set_shadow_f5(const void *addr, size_t size); > +void __asan_set_shadow_f8(const void *addr, size_t size); > + > #endif Acked-by: Dmitry Vyukov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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