From: Vlastimil Babka <vbabka@suse.cz> To: Andrey Konovalov <andreyknvl@gmail.com>, Sebastian Andrzej Siewior <bigeasy@linutronix.de>, Andrew Morton <akpm@linux-foundation.org> Cc: andrey.konovalov@linux.dev, Marco Elver <elver@google.com>, Alexander Potapenko <glider@google.com>, Dmitry Vyukov <dvyukov@google.com>, Andrey Ryabinin <ryabinin.a.a@gmail.com>, kasan-dev <kasan-dev@googlegroups.com>, Linux Memory Management List <linux-mm@kvack.org>, Vincenzo Frascino <vincenzo.frascino@arm.com>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Linux ARM <linux-arm-kernel@lists.infradead.org>, Peter Collingbourne <pcc@google.com>, Evgenii Stepanov <eugenis@google.com>, LKML <linux-kernel@vger.kernel.org>, Andrey Konovalov <andreyknvl@google.com>, Matthew Wilcox <willy@infradead.org> Subject: Re: [PATCH v6 27/39] kasan, mm: only define ___GFP_SKIP_KASAN_POISON with HW_TAGS Date: Wed, 23 Mar 2022 14:57:30 +0100 [thread overview] Message-ID: <b4d598ac-006e-1de3-21e5-8afa6aea0538@suse.cz> (raw) In-Reply-To: <CA+fCnZeG5DbxcnER1yWkJ50605_4E1xPtgeTEsSEc89qUg4w6g@mail.gmail.com> On 3/23/22 14:36, Andrey Konovalov wrote: > On Wed, Mar 23, 2022 at 2:02 PM Sebastian Andrzej Siewior > <bigeasy@linutronix.de> wrote: >> >> On 2022-03-23 12:48:29 [+0100], Vlastimil Babka wrote: >>>> +#ifdef CONFIG_KASAN_HW_TAGS >>>> #define ___GFP_SKIP_KASAN_POISON 0x1000000u >>>> +#else >>>> +#define ___GFP_SKIP_KASAN_POISON 0 >>>> +#endif >>>> #ifdef CONFIG_LOCKDEP >>>> #define ___GFP_NOLOCKDEP 0x2000000u >>>> #else >>>> @@ -251,7 +255,9 @@ struct vm_area_struct; >>>> #define __GFP_NOLOCKDEP ((__force gfp_t)___GFP_NOLOCKDEP) >>>> >>>> /* Room for N __GFP_FOO bits */ >>>> -#define __GFP_BITS_SHIFT (25 + IS_ENABLED(CONFIG_LOCKDEP)) >>>> +#define __GFP_BITS_SHIFT (24 + \ >>>> + IS_ENABLED(CONFIG_KASAN_HW_TAGS) + \ >>>> + IS_ENABLED(CONFIG_LOCKDEP)) >>> >>> This breaks __GFP_NOLOCKDEP, see: >>> https://lore.kernel.org/all/YjoJ4CzB3yfWSV1F@linutronix.de/ >> >> This could work because ___GFP_NOLOCKDEP is still 0x2000000u. In >> ("kasan, page_alloc: allow skipping memory init for HW_TAGS") >> https://lore.kernel.org/all/0d53efeff345de7d708e0baa0d8829167772521e.1643047180.git.andreyknvl@google.com/ >> >> This is replaced with 0x8000000u which breaks lockdep. >> >> Sebastian > > Hi Sebastian, > > Indeed, sorry for breaking lockdep. Thank you for the report! > > I wonder what's the proper fix for this. Perhaps, don't hide KASAN GFP > bits under CONFIG_KASAN_HW_TAGS? And then do: > > #define __GFP_BITS_SHIFT (27 + IS_ENABLED(CONFIG_LOCKDEP)) > > Vlastimil, Andrew do you have any preference? I guess it's the simplest thing to do for now. For the future we can still improve and handle all combinations of kasan/lockdep to occupy as few bits as possible and set the shift/mask appropriately. Or consider first if it's necessary anyway. I don't know if we really expect at any point to start triggering the BUILD_BUG_ON() in radix_tree_init() and then only some combination of configs will reduce the flags to a number that works. Or is there anything else that depends on __GFP_BITS_SHIFT? I mean if we don't expect to go this way, we can just define __GFP_BITS_SHIFT as a constant that assumes all the config-dependent flags to be defined (not zero). > If my suggestion sounds good, Andrew, could you directly apply the > changes? They are needed for these 3 patches: > > kasan, page_alloc: allow skipping memory init for HW_TAGS > kasan, page_alloc: allow skipping unpoisoning for HW_TAGS > kasan, mm: only define ___GFP_SKIP_KASAN_POISON with HW_TAGS > > As these depend on each other, I can't send separate patches that can > be folded for all 3. > > Thanks!
WARNING: multiple messages have this Message-ID (diff)
From: Vlastimil Babka <vbabka@suse.cz> To: Andrey Konovalov <andreyknvl@gmail.com>, Sebastian Andrzej Siewior <bigeasy@linutronix.de>, Andrew Morton <akpm@linux-foundation.org> Cc: andrey.konovalov@linux.dev, Marco Elver <elver@google.com>, Alexander Potapenko <glider@google.com>, Dmitry Vyukov <dvyukov@google.com>, Andrey Ryabinin <ryabinin.a.a@gmail.com>, kasan-dev <kasan-dev@googlegroups.com>, Linux Memory Management List <linux-mm@kvack.org>, Vincenzo Frascino <vincenzo.frascino@arm.com>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Linux ARM <linux-arm-kernel@lists.infradead.org>, Peter Collingbourne <pcc@google.com>, Evgenii Stepanov <eugenis@google.com>, LKML <linux-kernel@vger.kernel.org>, Andrey Konovalov <andreyknvl@google.com>, Matthew Wilcox <willy@infradead.org> Subject: Re: [PATCH v6 27/39] kasan, mm: only define ___GFP_SKIP_KASAN_POISON with HW_TAGS Date: Wed, 23 Mar 2022 14:57:30 +0100 [thread overview] Message-ID: <b4d598ac-006e-1de3-21e5-8afa6aea0538@suse.cz> (raw) In-Reply-To: <CA+fCnZeG5DbxcnER1yWkJ50605_4E1xPtgeTEsSEc89qUg4w6g@mail.gmail.com> On 3/23/22 14:36, Andrey Konovalov wrote: > On Wed, Mar 23, 2022 at 2:02 PM Sebastian Andrzej Siewior > <bigeasy@linutronix.de> wrote: >> >> On 2022-03-23 12:48:29 [+0100], Vlastimil Babka wrote: >>>> +#ifdef CONFIG_KASAN_HW_TAGS >>>> #define ___GFP_SKIP_KASAN_POISON 0x1000000u >>>> +#else >>>> +#define ___GFP_SKIP_KASAN_POISON 0 >>>> +#endif >>>> #ifdef CONFIG_LOCKDEP >>>> #define ___GFP_NOLOCKDEP 0x2000000u >>>> #else >>>> @@ -251,7 +255,9 @@ struct vm_area_struct; >>>> #define __GFP_NOLOCKDEP ((__force gfp_t)___GFP_NOLOCKDEP) >>>> >>>> /* Room for N __GFP_FOO bits */ >>>> -#define __GFP_BITS_SHIFT (25 + IS_ENABLED(CONFIG_LOCKDEP)) >>>> +#define __GFP_BITS_SHIFT (24 + \ >>>> + IS_ENABLED(CONFIG_KASAN_HW_TAGS) + \ >>>> + IS_ENABLED(CONFIG_LOCKDEP)) >>> >>> This breaks __GFP_NOLOCKDEP, see: >>> https://lore.kernel.org/all/YjoJ4CzB3yfWSV1F@linutronix.de/ >> >> This could work because ___GFP_NOLOCKDEP is still 0x2000000u. In >> ("kasan, page_alloc: allow skipping memory init for HW_TAGS") >> https://lore.kernel.org/all/0d53efeff345de7d708e0baa0d8829167772521e.1643047180.git.andreyknvl@google.com/ >> >> This is replaced with 0x8000000u which breaks lockdep. >> >> Sebastian > > Hi Sebastian, > > Indeed, sorry for breaking lockdep. Thank you for the report! > > I wonder what's the proper fix for this. Perhaps, don't hide KASAN GFP > bits under CONFIG_KASAN_HW_TAGS? And then do: > > #define __GFP_BITS_SHIFT (27 + IS_ENABLED(CONFIG_LOCKDEP)) > > Vlastimil, Andrew do you have any preference? I guess it's the simplest thing to do for now. For the future we can still improve and handle all combinations of kasan/lockdep to occupy as few bits as possible and set the shift/mask appropriately. Or consider first if it's necessary anyway. I don't know if we really expect at any point to start triggering the BUILD_BUG_ON() in radix_tree_init() and then only some combination of configs will reduce the flags to a number that works. Or is there anything else that depends on __GFP_BITS_SHIFT? I mean if we don't expect to go this way, we can just define __GFP_BITS_SHIFT as a constant that assumes all the config-dependent flags to be defined (not zero). > If my suggestion sounds good, Andrew, could you directly apply the > changes? They are needed for these 3 patches: > > kasan, page_alloc: allow skipping memory init for HW_TAGS > kasan, page_alloc: allow skipping unpoisoning for HW_TAGS > kasan, mm: only define ___GFP_SKIP_KASAN_POISON with HW_TAGS > > As these depend on each other, I can't send separate patches that can > be folded for all 3. > > Thanks! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-03-23 13:57 UTC|newest] Thread overview: 113+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-01-24 18:02 [PATCH v6 00/39] kasan, vmalloc, arm64: add vmalloc tagging support for SW/HW_TAGS andrey.konovalov 2022-01-24 18:02 ` andrey.konovalov 2022-01-24 18:02 ` [PATCH v6 01/39] kasan, page_alloc: deduplicate should_skip_kasan_poison andrey.konovalov 2022-01-24 18:02 ` andrey.konovalov 2022-01-24 18:02 ` [PATCH v6 02/39] kasan, page_alloc: move tag_clear_highpage out of kernel_init_free_pages andrey.konovalov 2022-01-24 18:02 ` andrey.konovalov 2022-01-24 18:02 ` [PATCH v6 03/39] kasan, page_alloc: merge kasan_free_pages into free_pages_prepare andrey.konovalov 2022-01-24 18:02 ` andrey.konovalov 2022-01-24 18:02 ` [PATCH v6 04/39] kasan, page_alloc: simplify kasan_poison_pages call site andrey.konovalov 2022-01-24 18:02 ` andrey.konovalov 2022-01-24 18:02 ` [PATCH v6 05/39] kasan, page_alloc: init memory of skipped pages on free andrey.konovalov 2022-01-24 18:02 ` andrey.konovalov 2022-01-24 18:02 ` [PATCH v6 06/39] kasan: drop skip_kasan_poison variable in free_pages_prepare andrey.konovalov 2022-01-24 18:02 ` andrey.konovalov 2022-01-24 18:02 ` [PATCH v6 07/39] mm: clarify __GFP_ZEROTAGS comment andrey.konovalov 2022-01-24 18:02 ` andrey.konovalov 2022-01-24 18:02 ` [PATCH v6 08/39] kasan: only apply __GFP_ZEROTAGS when memory is zeroed andrey.konovalov 2022-01-24 18:02 ` andrey.konovalov 2022-01-24 18:02 ` [PATCH v6 09/39] kasan, page_alloc: refactor init checks in post_alloc_hook andrey.konovalov 2022-01-24 18:02 ` andrey.konovalov 2022-01-24 18:02 ` [PATCH v6 10/39] kasan, page_alloc: merge kasan_alloc_pages into post_alloc_hook andrey.konovalov 2022-01-24 18:02 ` andrey.konovalov 2022-01-24 18:02 ` [PATCH v6 11/39] kasan, page_alloc: combine tag_clear_highpage calls in post_alloc_hook andrey.konovalov 2022-01-24 18:02 ` andrey.konovalov 2022-01-24 18:02 ` [PATCH v6 12/39] kasan, page_alloc: move SetPageSkipKASanPoison " andrey.konovalov 2022-01-24 18:02 ` andrey.konovalov 2022-01-24 18:02 ` [PATCH v6 13/39] kasan, page_alloc: move kernel_init_free_pages " andrey.konovalov 2022-01-24 18:02 ` andrey.konovalov 2022-01-24 18:02 ` [PATCH v6 14/39] kasan, page_alloc: rework kasan_unpoison_pages call site andrey.konovalov 2022-01-24 18:02 ` andrey.konovalov 2022-01-24 18:02 ` [PATCH v6 15/39] kasan: clean up metadata byte definitions andrey.konovalov 2022-01-24 18:02 ` andrey.konovalov 2022-01-24 18:02 ` [PATCH v6 16/39] kasan: define KASAN_VMALLOC_INVALID for SW_TAGS andrey.konovalov 2022-01-24 18:02 ` andrey.konovalov 2022-01-24 18:04 ` [PATCH v6 17/39] kasan, x86, arm64, s390: rename functions for modules shadow andrey.konovalov 2022-01-24 18:04 ` andrey.konovalov 2022-01-24 18:04 ` [PATCH v6 18/39] kasan, vmalloc: drop outdated VM_KASAN comment andrey.konovalov 2022-01-24 18:04 ` andrey.konovalov 2022-01-24 18:04 ` [PATCH v6 19/39] kasan: reorder vmalloc hooks andrey.konovalov 2022-01-24 18:04 ` andrey.konovalov 2022-01-24 18:04 ` [PATCH v6 20/39] kasan: add wrappers for " andrey.konovalov 2022-01-24 18:04 ` andrey.konovalov 2022-01-24 18:04 ` [PATCH v6 21/39] kasan, vmalloc: reset tags in vmalloc functions andrey.konovalov 2022-01-24 18:04 ` andrey.konovalov 2022-01-24 18:04 ` [PATCH v6 22/39] kasan, fork: reset pointer tags of vmapped stacks andrey.konovalov 2022-01-24 18:04 ` andrey.konovalov 2022-01-24 18:04 ` [PATCH v6 23/39] kasan, arm64: " andrey.konovalov 2022-01-24 18:04 ` andrey.konovalov 2022-01-24 18:04 ` [PATCH v6 24/39] kasan, vmalloc: add vmalloc tagging for SW_TAGS andrey.konovalov 2022-01-24 18:04 ` andrey.konovalov 2022-01-24 18:04 ` [PATCH v6 25/39] kasan, vmalloc, arm64: mark vmalloc mappings as pgprot_tagged andrey.konovalov 2022-01-24 18:04 ` andrey.konovalov 2022-01-24 18:05 ` [PATCH v6 26/39] kasan, vmalloc: unpoison VM_ALLOC pages after mapping andrey.konovalov 2022-01-24 18:05 ` andrey.konovalov 2022-01-24 18:05 ` [PATCH v6 27/39] kasan, mm: only define ___GFP_SKIP_KASAN_POISON with HW_TAGS andrey.konovalov 2022-01-24 18:05 ` andrey.konovalov 2022-03-23 11:48 ` Vlastimil Babka 2022-03-23 11:48 ` Vlastimil Babka 2022-03-23 13:02 ` Sebastian Andrzej Siewior 2022-03-23 13:02 ` Sebastian Andrzej Siewior 2022-03-23 13:19 ` Vlastimil Babka 2022-03-23 13:19 ` Vlastimil Babka 2022-03-23 13:36 ` Andrey Konovalov 2022-03-23 13:36 ` Andrey Konovalov 2022-03-23 13:57 ` Vlastimil Babka [this message] 2022-03-23 13:57 ` Vlastimil Babka 2022-03-23 15:11 ` Matthew Wilcox 2022-03-23 15:11 ` Matthew Wilcox 2022-03-25 21:13 ` Andrew Morton 2022-03-25 21:13 ` Andrew Morton 2022-01-24 18:05 ` [PATCH v6 28/39] kasan, page_alloc: allow skipping unpoisoning for HW_TAGS andrey.konovalov 2022-01-24 18:05 ` andrey.konovalov 2022-01-24 18:05 ` [PATCH v6 29/39] kasan, page_alloc: allow skipping memory init " andrey.konovalov 2022-01-24 18:05 ` andrey.konovalov 2022-01-24 18:05 ` [PATCH v6 30/39] kasan, vmalloc: add vmalloc tagging " andrey.konovalov 2022-01-24 18:05 ` andrey.konovalov 2022-01-25 3:17 ` kernel test robot 2022-01-24 18:05 ` [PATCH v6 31/39] kasan, vmalloc: only tag normal vmalloc allocations andrey.konovalov 2022-01-24 18:05 ` andrey.konovalov 2022-01-25 4:19 ` kernel test robot 2022-01-25 7:56 ` kernel test robot 2022-03-08 15:17 ` Vasily Gorbik 2022-03-08 15:17 ` Vasily Gorbik 2022-03-08 15:30 ` Andrey Konovalov 2022-03-08 15:30 ` Andrey Konovalov 2022-03-08 15:48 ` Vasily Gorbik 2022-03-08 15:48 ` Vasily Gorbik 2022-01-24 18:05 ` [PATCH v6 32/39] kasan, arm64: don't tag executable " andrey.konovalov 2022-01-24 18:05 ` andrey.konovalov 2022-01-24 18:05 ` [PATCH v6 33/39] kasan: mark kasan_arg_stacktrace as __initdata andrey.konovalov 2022-01-24 18:05 ` andrey.konovalov 2022-01-24 18:05 ` [PATCH v6 34/39] kasan: clean up feature flags for HW_TAGS mode andrey.konovalov 2022-01-24 18:05 ` andrey.konovalov 2022-01-24 18:05 ` [PATCH v6 35/39] kasan: add kasan.vmalloc command line flag andrey.konovalov 2022-01-24 18:05 ` andrey.konovalov 2022-01-24 18:05 ` [PATCH v6 36/39] kasan: allow enabling KASAN_VMALLOC and SW/HW_TAGS andrey.konovalov 2022-01-24 18:05 ` andrey.konovalov 2022-01-24 18:05 ` [PATCH v6 37/39] arm64: select KASAN_VMALLOC for SW/HW_TAGS modes andrey.konovalov 2022-01-24 18:05 ` andrey.konovalov 2022-01-24 18:05 ` [PATCH v6 38/39] kasan: documentation updates andrey.konovalov 2022-01-24 18:05 ` andrey.konovalov 2022-01-24 18:05 ` [PATCH v6 39/39] kasan: improve vmalloc tests andrey.konovalov 2022-01-24 18:05 ` andrey.konovalov 2022-01-24 18:09 ` [PATCH v6 00/39] kasan, vmalloc, arm64: add vmalloc tagging support for SW/HW_TAGS Marco Elver 2022-01-24 18:09 ` Marco Elver 2022-01-24 18:32 ` Andrey Konovalov 2022-01-24 18:32 ` Andrey Konovalov 2022-04-28 14:13 ` Qian Cai 2022-04-28 14:13 ` Qian Cai 2022-04-28 15:28 ` Andrey Konovalov 2022-04-28 15:28 ` Andrey Konovalov 2022-04-28 16:12 ` Qian Cai 2022-04-28 16:12 ` Qian Cai
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