From: Daniel Axtens <dja@axtens.net> To: Andrey Ryabinin <aryabinin@virtuozzo.com>, kasan-dev@googlegroups.com, linux-mm@kvack.org, x86@kernel.org, glider@google.com, luto@kernel.org, linux-kernel@vger.kernel.org, mark.rutland@arm.com, dvyukov@google.com, christophe.leroy@c-s.fr Cc: linuxppc-dev@lists.ozlabs.org, gor@linux.ibm.com, Andrew Morton <akpm@linux-foundation.org> Subject: Re: [PATCH v10 4/5] x86/kasan: support KASAN_VMALLOC Date: Thu, 31 Oct 2019 00:50:05 +1100 [thread overview] Message-ID: <87sgnamjg2.fsf@dja-thinkpad.axtens.net> (raw) In-Reply-To: <a144eaca-d7e1-1a18-5975-bd0bfdb9450e@virtuozzo.com> Andrey Ryabinin <aryabinin@virtuozzo.com> writes: > On 10/29/19 7:20 AM, Daniel Axtens wrote: >> In the case where KASAN directly allocates memory to back vmalloc >> space, don't map the early shadow page over it. >> >> We prepopulate pgds/p4ds for the range that would otherwise be empty. >> This is required to get it synced to hardware on boot, allowing the >> lower levels of the page tables to be filled dynamically. >> >> Acked-by: Dmitry Vyukov <dvyukov@google.com> >> Signed-off-by: Daniel Axtens <dja@axtens.net> >> >> --- > >> +static void __init kasan_shallow_populate_pgds(void *start, void *end) >> +{ >> + unsigned long addr, next; >> + pgd_t *pgd; >> + void *p; >> + int nid = early_pfn_to_nid((unsigned long)start); > > This doesn't make sense. start is not even a pfn. With linear mapping > we try to identify nid to have the shadow on the same node as memory. But > in this case we don't have memory or the corresponding shadow (yet), > we only install pgd/p4d. > I guess we could just use NUMA_NO_NODE. Ah wow, that's quite the clanger on my part. There are a couple of other invocations of early_pfn_to_nid in that file that use an address directly, but at least they reference actual memory. I'll send a separate patch to fix those up. > The rest looks ok, so with that fixed: > > Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Thanks heaps! I've fixed up the nit you identifed in the first patch, and I agree that the last patch probably isn't needed. I'll respin the series shortly. Regards, Daniel
WARNING: multiple messages have this Message-ID (diff)
From: Daniel Axtens <dja@axtens.net> To: Andrey Ryabinin <aryabinin@virtuozzo.com>, kasan-dev@googlegroups.com, linux-mm@kvack.org, x86@kernel.org, glider@google.com, luto@kernel.org, linux-kernel@vger.kernel.org, mark.rutland@arm.com, dvyukov@google.com, christophe.leroy@c-s.fr Cc: Andrew Morton <akpm@linux-foundation.org>, linuxppc-dev@lists.ozlabs.org, gor@linux.ibm.com Subject: Re: [PATCH v10 4/5] x86/kasan: support KASAN_VMALLOC Date: Thu, 31 Oct 2019 00:50:05 +1100 [thread overview] Message-ID: <87sgnamjg2.fsf@dja-thinkpad.axtens.net> (raw) In-Reply-To: <a144eaca-d7e1-1a18-5975-bd0bfdb9450e@virtuozzo.com> Andrey Ryabinin <aryabinin@virtuozzo.com> writes: > On 10/29/19 7:20 AM, Daniel Axtens wrote: >> In the case where KASAN directly allocates memory to back vmalloc >> space, don't map the early shadow page over it. >> >> We prepopulate pgds/p4ds for the range that would otherwise be empty. >> This is required to get it synced to hardware on boot, allowing the >> lower levels of the page tables to be filled dynamically. >> >> Acked-by: Dmitry Vyukov <dvyukov@google.com> >> Signed-off-by: Daniel Axtens <dja@axtens.net> >> >> --- > >> +static void __init kasan_shallow_populate_pgds(void *start, void *end) >> +{ >> + unsigned long addr, next; >> + pgd_t *pgd; >> + void *p; >> + int nid = early_pfn_to_nid((unsigned long)start); > > This doesn't make sense. start is not even a pfn. With linear mapping > we try to identify nid to have the shadow on the same node as memory. But > in this case we don't have memory or the corresponding shadow (yet), > we only install pgd/p4d. > I guess we could just use NUMA_NO_NODE. Ah wow, that's quite the clanger on my part. There are a couple of other invocations of early_pfn_to_nid in that file that use an address directly, but at least they reference actual memory. I'll send a separate patch to fix those up. > The rest looks ok, so with that fixed: > > Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Thanks heaps! I've fixed up the nit you identifed in the first patch, and I agree that the last patch probably isn't needed. I'll respin the series shortly. Regards, Daniel
next prev parent reply other threads:[~2019-10-30 13:50 UTC|newest] Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-10-29 4:20 [PATCH v10 0/5] kasan: support backing vmalloc space with real shadow memory Daniel Axtens 2019-10-29 4:20 ` [PATCH v10 1/5] " Daniel Axtens 2019-10-29 16:42 ` Andrey Ryabinin 2019-10-29 16:42 ` Andrey Ryabinin 2019-10-30 14:29 ` Uladzislau Rezki 2019-10-30 14:29 ` Uladzislau Rezki 2019-10-31 9:36 ` Daniel Axtens 2019-10-31 9:36 ` Daniel Axtens 2019-10-29 4:20 ` [PATCH v10 2/5] kasan: add test for vmalloc Daniel Axtens 2019-10-29 16:43 ` Andrey Ryabinin 2019-10-29 4:20 ` [PATCH v10 3/5] fork: support VMAP_STACK with KASAN_VMALLOC Daniel Axtens 2019-10-29 17:07 ` Andrey Ryabinin 2019-10-29 17:07 ` Andrey Ryabinin 2019-10-29 4:20 ` [PATCH v10 4/5] x86/kasan: support KASAN_VMALLOC Daniel Axtens 2019-10-29 17:21 ` Andrey Ryabinin 2019-10-29 17:21 ` Andrey Ryabinin 2019-10-30 13:50 ` Daniel Axtens [this message] 2019-10-30 13:50 ` Daniel Axtens 2019-10-30 14:12 ` Andrey Ryabinin 2019-10-30 14:12 ` Andrey Ryabinin 2019-10-30 14:21 ` Daniel Axtens 2019-10-30 14:21 ` Daniel Axtens 2019-10-29 4:20 ` [PATCH v10 5/5] kasan debug: track pages allocated for vmalloc shadow Daniel Axtens 2019-10-29 17:34 ` Andrey Ryabinin 2019-10-29 17:34 ` Andrey Ryabinin
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