From: James Morse <james.morse@arm.com> To: kexec@lists.infradead.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org Cc: Eric Biederman <ebiederm@xmission.com>, Andrew Morton <akpm@linux-foundation.org>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Anshuman Khandual <anshuman.khandual@arm.com>, Bhupesh Sharma <bhsharma@redhat.com>, James Morse <james.morse@arm.com> Subject: [PATCH 0/3] kexec/memory_hotplug: Prevent removal and accidental use Date: Thu, 26 Mar 2020 18:07:27 +0000 [thread overview] Message-ID: <20200326180730.4754-1-james.morse@arm.com> (raw) Hello! arm64 recently queued support for memory hotremove, which led to some new corner cases for kexec. If the kexec segments are loaded for a removable region, that region may be removed before kexec actually occurs. This causes the first kernel to lockup when applying the relocations. (I've triggered this on x86 too). The first patch adds a memory notifier for kexec so that it can refuse to allow in-use regions to be taken offline. This doesn't solve the problem for arm64, where the new kernel must initially rely on the data structures from the first boot to describe memory. These don't describe hotpluggable memory. If kexec places the kernel in one of these regions, it must also provide a DT that describes the region in which the kernel was mapped as memory. (and somehow ensure its always present in the future...) To prevent this from happening accidentally with unaware user-space, patches two and three allow arm64 to give these regions a different name. This is a change in behaviour for arm64 as memory hotadd and hotremove were added separately. I haven't tried kdump. Unaware kdump from user-space probably won't describe the hotplug regions if the name is different, which saves us from problems if the memory is no longer present at kdump time, but means the vmcore is incomplete. These patches are based on arm64's for-next/core branch, but can all be merged independently. Thanks, James Morse (3): kexec: Prevent removal of memory in use by a loaded kexec image mm/memory_hotplug: Allow arch override of non boot memory resource names arm64: memory: Give hotplug memory a different resource name arch/arm64/include/asm/memory.h | 11 +++++++ kernel/kexec_core.c | 56 +++++++++++++++++++++++++++++++++ mm/memory_hotplug.c | 6 +++- 3 files changed, 72 insertions(+), 1 deletion(-) -- 2.25.1
WARNING: multiple messages have this Message-ID (diff)
From: James Morse <james.morse@arm.com> To: kexec@lists.infradead.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org Cc: Anshuman Khandual <anshuman.khandual@arm.com>, Catalin Marinas <catalin.marinas@arm.com>, Bhupesh Sharma <bhsharma@redhat.com>, James Morse <james.morse@arm.com>, Eric Biederman <ebiederm@xmission.com>, Andrew Morton <akpm@linux-foundation.org>, Will Deacon <will@kernel.org> Subject: [PATCH 0/3] kexec/memory_hotplug: Prevent removal and accidental use Date: Thu, 26 Mar 2020 18:07:27 +0000 [thread overview] Message-ID: <20200326180730.4754-1-james.morse@arm.com> (raw) Hello! arm64 recently queued support for memory hotremove, which led to some new corner cases for kexec. If the kexec segments are loaded for a removable region, that region may be removed before kexec actually occurs. This causes the first kernel to lockup when applying the relocations. (I've triggered this on x86 too). The first patch adds a memory notifier for kexec so that it can refuse to allow in-use regions to be taken offline. This doesn't solve the problem for arm64, where the new kernel must initially rely on the data structures from the first boot to describe memory. These don't describe hotpluggable memory. If kexec places the kernel in one of these regions, it must also provide a DT that describes the region in which the kernel was mapped as memory. (and somehow ensure its always present in the future...) To prevent this from happening accidentally with unaware user-space, patches two and three allow arm64 to give these regions a different name. This is a change in behaviour for arm64 as memory hotadd and hotremove were added separately. I haven't tried kdump. Unaware kdump from user-space probably won't describe the hotplug regions if the name is different, which saves us from problems if the memory is no longer present at kdump time, but means the vmcore is incomplete. These patches are based on arm64's for-next/core branch, but can all be merged independently. Thanks, James Morse (3): kexec: Prevent removal of memory in use by a loaded kexec image mm/memory_hotplug: Allow arch override of non boot memory resource names arm64: memory: Give hotplug memory a different resource name arch/arm64/include/asm/memory.h | 11 +++++++ kernel/kexec_core.c | 56 +++++++++++++++++++++++++++++++++ mm/memory_hotplug.c | 6 +++- 3 files changed, 72 insertions(+), 1 deletion(-) -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2020-03-26 18:08 UTC|newest] Thread overview: 264+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-03-26 18:07 James Morse [this message] 2020-03-26 18:07 ` [PATCH 0/3] kexec/memory_hotplug: Prevent removal and accidental use James Morse 2020-03-26 18:07 ` [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image James Morse 2020-03-26 18:07 ` James Morse 2020-03-27 0:43 ` Anshuman Khandual 2020-03-27 0:43 ` Anshuman Khandual 2020-03-27 2:54 ` Baoquan He 2020-03-27 2:54 ` Baoquan He 2020-03-27 15:46 ` James Morse 2020-03-27 15:46 ` James Morse 2020-03-27 2:34 ` Baoquan He 2020-03-27 2:34 ` Baoquan He 2020-03-27 9:30 ` David Hildenbrand 2020-03-27 9:30 ` David Hildenbrand 2020-03-27 16:56 ` James Morse 2020-03-27 16:56 ` James Morse 2020-03-27 17:06 ` David Hildenbrand 2020-03-27 17:06 ` David Hildenbrand 2020-03-27 18:07 ` James Morse 2020-03-27 18:07 ` James Morse 2020-03-27 18:52 ` David Hildenbrand 2020-03-27 18:52 ` David Hildenbrand 2020-03-30 13:00 ` James Morse 2020-03-30 13:00 ` James Morse 2020-03-30 13:13 ` David Hildenbrand 2020-03-30 13:13 ` David Hildenbrand 2020-03-30 17:17 ` James Morse 2020-03-30 17:17 ` James Morse 2020-03-30 18:14 ` David Hildenbrand 2020-03-30 18:14 ` David Hildenbrand 2020-04-10 19:10 ` Andrew Morton 2020-04-10 19:10 ` Andrew Morton 2020-04-10 19:10 ` Andrew Morton 2020-04-11 3:44 ` Baoquan He 2020-04-11 3:44 ` Baoquan He 2020-04-11 3:44 ` Baoquan He 2020-04-11 9:30 ` Russell King - ARM Linux admin 2020-04-11 9:30 ` Russell King - ARM Linux admin 2020-04-11 9:30 ` Russell King - ARM Linux admin 2020-04-11 9:58 ` David Hildenbrand 2020-04-11 9:58 ` David Hildenbrand 2020-04-11 9:58 ` David Hildenbrand 2020-04-12 5:35 ` Baoquan He 2020-04-12 5:35 ` Baoquan He 2020-04-12 5:35 ` Baoquan He 2020-04-12 8:08 ` Russell King - ARM Linux admin 2020-04-12 8:08 ` Russell King - ARM Linux admin 2020-04-12 8:08 ` Russell King - ARM Linux admin 2020-04-12 19:52 ` Eric W. Biederman 2020-04-12 19:52 ` Eric W. Biederman 2020-04-12 19:52 ` Eric W. Biederman 2020-04-12 20:37 ` Bhupesh SHARMA 2020-04-12 20:37 ` Bhupesh SHARMA 2020-04-12 20:37 ` Bhupesh SHARMA 2020-04-13 2:37 ` Baoquan He 2020-04-13 2:37 ` Baoquan He 2020-04-13 2:37 ` Baoquan He 2020-04-13 13:15 ` Eric W. Biederman 2020-04-13 13:15 ` Eric W. Biederman 2020-04-13 13:15 ` Eric W. Biederman 2020-04-13 23:01 ` Andrew Morton 2020-04-13 23:01 ` Andrew Morton 2020-04-13 23:01 ` Andrew Morton 2020-04-14 6:13 ` Eric W. Biederman 2020-04-14 6:13 ` Eric W. Biederman 2020-04-14 6:13 ` Eric W. Biederman 2020-04-14 6:40 ` Baoquan He 2020-04-14 6:40 ` Baoquan He 2020-04-14 6:40 ` Baoquan He 2020-04-14 6:51 ` Baoquan He 2020-04-14 6:51 ` Baoquan He 2020-04-14 6:51 ` Baoquan He 2020-04-14 8:00 ` David Hildenbrand 2020-04-14 8:00 ` David Hildenbrand 2020-04-14 8:00 ` David Hildenbrand 2020-04-14 9:22 ` Baoquan He 2020-04-14 9:22 ` Baoquan He 2020-04-14 9:22 ` Baoquan He 2020-04-14 9:22 ` Baoquan He 2020-04-14 9:37 ` David Hildenbrand 2020-04-14 9:37 ` David Hildenbrand 2020-04-14 9:37 ` David Hildenbrand 2020-04-14 9:37 ` David Hildenbrand 2020-04-14 14:39 ` Baoquan He 2020-04-14 14:39 ` Baoquan He 2020-04-14 14:39 ` Baoquan He 2020-04-14 14:39 ` Baoquan He 2020-04-14 14:49 ` David Hildenbrand 2020-04-14 14:49 ` David Hildenbrand 2020-04-14 14:49 ` David Hildenbrand 2020-04-14 14:49 ` David Hildenbrand 2020-04-15 2:35 ` Baoquan He 2020-04-15 2:35 ` Baoquan He 2020-04-15 2:35 ` Baoquan He 2020-04-15 2:35 ` Baoquan He 2020-04-16 13:31 ` David Hildenbrand 2020-04-16 13:31 ` David Hildenbrand 2020-04-16 13:31 ` David Hildenbrand 2020-04-16 13:31 ` David Hildenbrand 2020-04-16 14:02 ` Baoquan He 2020-04-16 14:02 ` Baoquan He 2020-04-16 14:02 ` Baoquan He 2020-04-16 14:02 ` Baoquan He 2020-04-16 14:09 ` David Hildenbrand 2020-04-16 14:09 ` David Hildenbrand 2020-04-16 14:09 ` David Hildenbrand 2020-04-16 14:09 ` David Hildenbrand 2020-04-16 14:36 ` Baoquan He 2020-04-16 14:36 ` Baoquan He 2020-04-16 14:36 ` Baoquan He 2020-04-16 14:36 ` Baoquan He 2020-04-16 14:47 ` David Hildenbrand 2020-04-16 14:47 ` David Hildenbrand 2020-04-16 14:47 ` David Hildenbrand 2020-04-16 14:47 ` David Hildenbrand 2020-04-21 13:29 ` David Hildenbrand 2020-04-21 13:29 ` David Hildenbrand 2020-04-21 13:29 ` David Hildenbrand 2020-04-21 13:29 ` David Hildenbrand 2020-04-21 13:57 ` David Hildenbrand 2020-04-21 13:57 ` David Hildenbrand 2020-04-21 13:57 ` David Hildenbrand 2020-04-21 13:57 ` David Hildenbrand 2020-04-21 13:59 ` Eric W. Biederman 2020-04-21 13:59 ` Eric W. Biederman 2020-04-21 13:59 ` Eric W. Biederman 2020-04-21 13:59 ` Eric W. Biederman 2020-04-21 14:30 ` David Hildenbrand 2020-04-21 14:30 ` David Hildenbrand 2020-04-21 14:30 ` David Hildenbrand 2020-04-21 14:30 ` David Hildenbrand 2020-04-22 9:17 ` Baoquan He 2020-04-22 9:17 ` Baoquan He 2020-04-22 9:17 ` Baoquan He 2020-04-22 9:17 ` Baoquan He 2020-04-22 9:24 ` David Hildenbrand 2020-04-22 9:24 ` David Hildenbrand 2020-04-22 9:24 ` David Hildenbrand 2020-04-22 9:24 ` David Hildenbrand 2020-04-22 9:57 ` Baoquan He 2020-04-22 9:57 ` Baoquan He 2020-04-22 9:57 ` Baoquan He 2020-04-22 9:57 ` Baoquan He 2020-04-22 10:05 ` David Hildenbrand 2020-04-22 10:05 ` David Hildenbrand 2020-04-22 10:05 ` David Hildenbrand 2020-04-22 10:05 ` David Hildenbrand 2020-04-22 10:36 ` Baoquan He 2020-04-22 10:36 ` Baoquan He 2020-04-22 10:36 ` Baoquan He 2020-04-22 10:36 ` Baoquan He 2020-04-14 9:16 ` Dave Young 2020-04-14 9:16 ` Dave Young 2020-04-14 9:16 ` Dave Young 2020-04-14 9:38 ` Dave Young 2020-04-14 9:38 ` Dave Young 2020-04-14 9:38 ` Dave Young 2020-04-14 7:05 ` David Hildenbrand 2020-04-14 7:05 ` David Hildenbrand 2020-04-14 7:05 ` David Hildenbrand 2020-04-14 16:55 ` James Morse 2020-04-14 16:55 ` James Morse 2020-04-14 16:55 ` James Morse 2020-04-14 17:41 ` David Hildenbrand 2020-04-14 17:41 ` David Hildenbrand 2020-04-14 17:41 ` David Hildenbrand 2020-04-15 20:33 ` Eric W. Biederman 2020-04-15 20:33 ` Eric W. Biederman 2020-04-15 20:33 ` Eric W. Biederman 2020-04-22 12:28 ` James Morse 2020-04-22 12:28 ` James Morse 2020-04-22 12:28 ` James Morse 2020-04-22 15:25 ` Eric W. Biederman 2020-04-22 15:25 ` Eric W. Biederman 2020-04-22 15:25 ` Eric W. Biederman 2020-04-22 16:40 ` David Hildenbrand 2020-04-22 16:40 ` David Hildenbrand 2020-04-22 16:40 ` David Hildenbrand 2020-04-23 16:29 ` Eric W. Biederman 2020-04-23 16:29 ` Eric W. Biederman 2020-04-23 16:29 ` Eric W. Biederman 2020-04-24 7:39 ` David Hildenbrand 2020-04-24 7:39 ` David Hildenbrand 2020-04-24 7:39 ` David Hildenbrand 2020-04-24 7:41 ` David Hildenbrand 2020-04-24 7:41 ` David Hildenbrand 2020-04-24 7:41 ` David Hildenbrand 2020-05-01 16:55 ` James Morse 2020-05-01 16:55 ` James Morse 2020-05-01 16:55 ` James Morse 2020-03-26 18:07 ` [PATCH 2/3] mm/memory_hotplug: Allow arch override of non boot memory resource names James Morse 2020-03-26 18:07 ` James Morse 2020-03-27 9:59 ` David Hildenbrand 2020-03-27 9:59 ` David Hildenbrand 2020-03-27 15:39 ` James Morse 2020-03-27 15:39 ` James Morse 2020-03-30 13:23 ` David Hildenbrand 2020-03-30 13:23 ` David Hildenbrand 2020-03-30 17:17 ` James Morse 2020-03-30 17:17 ` James Morse 2020-04-02 5:49 ` Dave Young 2020-04-02 5:49 ` Dave Young 2020-04-02 5:49 ` Dave Young 2020-04-02 6:12 ` piliu 2020-04-02 6:12 ` piliu 2020-04-02 6:12 ` piliu 2020-04-14 17:21 ` James Morse 2020-04-14 17:21 ` James Morse 2020-04-14 17:21 ` James Morse 2020-04-15 20:36 ` Eric W. Biederman 2020-04-15 20:36 ` Eric W. Biederman 2020-04-15 20:36 ` Eric W. Biederman 2020-04-22 12:14 ` James Morse 2020-04-22 12:14 ` James Morse 2020-04-22 12:14 ` James Morse 2020-05-09 0:45 ` Andrew Morton 2020-05-09 0:45 ` Andrew Morton 2020-05-09 0:45 ` Andrew Morton 2020-05-11 8:35 ` David Hildenbrand 2020-05-11 8:35 ` David Hildenbrand 2020-05-11 8:35 ` David Hildenbrand 2020-03-26 18:07 ` [PATCH 3/3] arm64: memory: Give hotplug memory a different resource name James Morse 2020-03-26 18:07 ` James Morse 2020-03-30 19:01 ` David Hildenbrand 2020-03-30 19:01 ` David Hildenbrand 2020-04-15 20:37 ` Eric W. Biederman 2020-04-15 20:37 ` Eric W. Biederman 2020-04-15 20:37 ` Eric W. Biederman 2020-04-22 12:14 ` James Morse 2020-04-22 12:14 ` James Morse 2020-04-22 12:14 ` James Morse 2020-03-27 2:11 ` [PATCH 0/3] kexec/memory_hotplug: Prevent removal and accidental use Baoquan He 2020-03-27 2:11 ` Baoquan He 2020-03-27 15:40 ` James Morse 2020-03-27 15:40 ` James Morse 2020-03-27 9:27 ` David Hildenbrand 2020-03-27 9:27 ` David Hildenbrand 2020-03-27 15:42 ` James Morse 2020-03-27 15:42 ` James Morse 2020-03-30 13:18 ` David Hildenbrand 2020-03-30 13:18 ` David Hildenbrand 2020-03-30 13:55 ` Baoquan He 2020-03-30 13:55 ` Baoquan He 2020-03-30 17:17 ` James Morse 2020-03-30 17:17 ` James Morse 2020-03-31 3:46 ` Dave Young 2020-03-31 3:46 ` Dave Young 2020-04-14 17:31 ` James Morse 2020-04-14 17:31 ` James Morse 2020-04-14 17:31 ` James Morse 2020-03-31 3:38 ` Dave Young 2020-03-31 3:38 ` Dave Young 2020-04-15 20:29 ` Eric W. Biederman 2020-04-15 20:29 ` Eric W. Biederman 2020-04-15 20:29 ` Eric W. Biederman 2020-04-22 12:14 ` James Morse 2020-04-22 12:14 ` James Morse 2020-04-22 12:14 ` James Morse 2020-04-22 13:04 ` Eric W. Biederman 2020-04-22 13:04 ` Eric W. Biederman 2020-04-22 13:04 ` Eric W. Biederman 2020-04-22 15:40 ` James Morse 2020-04-22 15:40 ` James Morse 2020-04-22 15:40 ` James Morse
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