On 9/27/19 1:16 PM, David Hildenbrand wrote:
On 27.09.19 03:51, Aneesh Kumar K.V wrote:
On 9/27/19 4:15 AM, Andrew Morton wrote:
On Thu, 26 Sep 2019 17:55:51 +0530 "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx> wrote:
With altmap, all the resource pfns are not initialized. While initializing
pfn, altmap reserve space is skipped. Hence when removing pfn from zone skip
pfns that were never initialized.
Update memunmap_pages to calculate start and end pfn based on altmap
values. This fixes a kernel crash that is observed when destroying namespace.
[ 74.745056] BUG: Unable to handle kernel data access at 0xc00c000001400000
[ 74.745256] Faulting instruction address: 0xc0000000000b58b0
cpu 0x2: Vector: 300 (Data Access) at [c00000026ea93580]
pc: c0000000000b58b0: memset+0x68/0x104
lr: c0000000003eb008: page_init_poison+0x38/0x50
...
current = 0xc000000271c67d80
paca = 0xc00000003fffd680 irqmask: 0x03 irq_happened: 0x01
pid = 3665, comm = ndctl
[link register ] c0000000003eb008 page_init_poison+0x38/0x50
[c00000026ea93830] c0000000004754d4 remove_pfn_range_from_zone+0x64/0x3e0
[c00000026ea938a0] c0000000004b8a60 memunmap_pages+0x300/0x400
[c00000026ea93930] c0000000009e32a0 devm_action_release+0x30/0x50
Doesn't apply to mainline or -next. Which tree is this against?
After applying the patches from David on mainline. That is the reason I
replied to this thread. I should have mentioned in the email that it is
based on patch series "[PATCH v4 0/8] mm/memory_hotplug: Shrink zones
before removing memory"
So if I am not wrong, my patch "[PATCH v4 4/8] mm/memory_hotplug: Poison
memmap in remove_pfn_range_from_zone()" makes it show up that we
actually call _remove_pages() with wrong parameters, right?
If so, I guess it would be better for you to fix it before my series and
I will rebase my series on top of that.
I posted a patch that can be applied to mainline. I sent that as a reply
to this email. Can you include that and PATCH 2 as first two patches in
your series? That should help to locate the full patch series needed
for fixing the kernel crash.
-aneesh
