From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> To: dan.j.williams@intel.com, akpm@linux-foundation.org, David Hildenbrand <david@redhat.com> Cc: linux-mm@kvack.org, "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>, linux-nvdimm@lists.01.org Subject: [PATCH 1/2] mm/memunmap: Use the correct start and end pfn when removing pages from zone Date: Thu, 26 Sep 2019 17:55:51 +0530 [thread overview] Message-ID: <20190926122552.17905-1-aneesh.kumar@linux.ibm.com> (raw) In-Reply-To: <20190830091428.18399-1-david@redhat.com> 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 ... Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> --- mm/memremap.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/mm/memremap.c b/mm/memremap.c index 390bb3544589..76b98110031e 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -113,7 +113,8 @@ static void dev_pagemap_cleanup(struct dev_pagemap *pgmap) void memunmap_pages(struct dev_pagemap *pgmap) { struct resource *res = &pgmap->res; - unsigned long pfn = PHYS_PFN(res->start); + unsigned long start_pfn, end_pfn; + unsigned long pfn, nr_pages; int nid; dev_pagemap_kill(pgmap); @@ -121,14 +122,18 @@ void memunmap_pages(struct dev_pagemap *pgmap) put_page(pfn_to_page(pfn)); dev_pagemap_cleanup(pgmap); + start_pfn = pfn_first(pgmap); + end_pfn = pfn_end(pgmap); + nr_pages = end_pfn - start_pfn; + /* pages are dead and unused, undo the arch mapping */ - nid = page_to_nid(pfn_to_page(pfn)); + nid = page_to_nid(pfn_to_page(start_pfn)); mem_hotplug_begin(); - remove_pfn_range_from_zone(page_zone(pfn_to_page(pfn)), pfn, - PHYS_PFN(resource_size(res))); + remove_pfn_range_from_zone(page_zone(pfn_to_page(start_pfn)), + start_pfn, nr_pages); if (pgmap->type == MEMORY_DEVICE_PRIVATE) { - __remove_pages(pfn, PHYS_PFN(resource_size(res)), NULL); + __remove_pages(start_pfn, nr_pages, NULL); } else { arch_remove_memory(nid, res->start, resource_size(res), pgmap_altmap(pgmap)); -- 2.21.0 _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm
WARNING: multiple messages have this Message-ID (diff)
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> To: dan.j.williams@intel.com, akpm@linux-foundation.org, David Hildenbrand <david@redhat.com> Cc: linux-nvdimm@lists.01.org, linux-mm@kvack.org, "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Subject: [PATCH 1/2] mm/memunmap: Use the correct start and end pfn when removing pages from zone Date: Thu, 26 Sep 2019 17:55:51 +0530 [thread overview] Message-ID: <20190926122552.17905-1-aneesh.kumar@linux.ibm.com> (raw) In-Reply-To: <20190830091428.18399-1-david@redhat.com> 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 ... Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> --- mm/memremap.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/mm/memremap.c b/mm/memremap.c index 390bb3544589..76b98110031e 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -113,7 +113,8 @@ static void dev_pagemap_cleanup(struct dev_pagemap *pgmap) void memunmap_pages(struct dev_pagemap *pgmap) { struct resource *res = &pgmap->res; - unsigned long pfn = PHYS_PFN(res->start); + unsigned long start_pfn, end_pfn; + unsigned long pfn, nr_pages; int nid; dev_pagemap_kill(pgmap); @@ -121,14 +122,18 @@ void memunmap_pages(struct dev_pagemap *pgmap) put_page(pfn_to_page(pfn)); dev_pagemap_cleanup(pgmap); + start_pfn = pfn_first(pgmap); + end_pfn = pfn_end(pgmap); + nr_pages = end_pfn - start_pfn; + /* pages are dead and unused, undo the arch mapping */ - nid = page_to_nid(pfn_to_page(pfn)); + nid = page_to_nid(pfn_to_page(start_pfn)); mem_hotplug_begin(); - remove_pfn_range_from_zone(page_zone(pfn_to_page(pfn)), pfn, - PHYS_PFN(resource_size(res))); + remove_pfn_range_from_zone(page_zone(pfn_to_page(start_pfn)), + start_pfn, nr_pages); if (pgmap->type == MEMORY_DEVICE_PRIVATE) { - __remove_pages(pfn, PHYS_PFN(resource_size(res)), NULL); + __remove_pages(start_pfn, nr_pages, NULL); } else { arch_remove_memory(nid, res->start, resource_size(res), pgmap_altmap(pgmap)); -- 2.21.0
next prev parent reply other threads:[~2019-09-26 12:26 UTC|newest] Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-08-30 9:14 [PATCH v4 0/8] mm/memory_hotplug: Shrink zones before removing memory David Hildenbrand 2019-08-30 9:14 ` [PATCH v4 1/8] mm/memory_hotplug: Don't access uninitialized memmaps in shrink_pgdat_span() David Hildenbrand 2019-08-30 9:14 ` [PATCH v4 2/8] mm/memory_hotplug: Don't access uninitialized memmaps in shrink_zone_span() David Hildenbrand 2019-09-26 9:12 ` Aneesh Kumar K.V 2019-09-26 9:22 ` David Hildenbrand 2019-08-30 9:14 ` [PATCH v4 3/8] mm/memory_hotplug: Shrink zones when offlining memory David Hildenbrand 2019-08-30 9:14 ` David Hildenbrand 2019-08-30 9:14 ` [PATCH v4 4/8] mm/memory_hotplug: Poison memmap in remove_pfn_range_from_zone() David Hildenbrand 2019-09-26 9:10 ` Aneesh Kumar K.V 2019-09-26 9:14 ` David Hildenbrand 2019-08-30 9:14 ` [PATCH v4 5/8] mm/memory_hotplug: We always have a zone in find_(smallest|biggest)_section_pfn David Hildenbrand 2019-08-30 9:14 ` [PATCH v4 6/8] mm/memory_hotplug: Don't check for "all holes" in shrink_zone_span() David Hildenbrand 2019-08-30 9:14 ` [PATCH v4 7/8] mm/memory_hotplug: Drop local variables " David Hildenbrand 2019-08-30 9:14 ` [PATCH v4 8/8] mm/memory_hotplug: Cleanup __remove_pages() David Hildenbrand 2019-09-06 9:21 ` [PATCH v4 0/8] mm/memory_hotplug: Shrink zones before removing memory David Hildenbrand 2019-09-19 13:58 ` David Hildenbrand 2019-09-19 19:16 ` Andrew Morton 2019-09-20 8:16 ` David Hildenbrand 2019-09-26 12:25 ` Aneesh Kumar K.V [this message] 2019-09-26 12:25 ` [PATCH 1/2] mm/memunmap: Use the correct start and end pfn when removing pages from zone Aneesh Kumar K.V 2019-09-26 12:25 ` [PATCH 2/2] mm/memmap_init: Update variable name in memmap_init_zone Aneesh Kumar K.V 2019-09-26 12:25 ` Aneesh Kumar K.V 2019-09-26 12:56 ` David Hildenbrand 2019-09-26 12:56 ` David Hildenbrand 2019-09-26 13:38 ` Pankaj Gupta 2019-09-26 13:38 ` Pankaj Gupta 2019-09-26 12:43 ` [PATCH 1/2] mm/memunmap: Use the correct start and end pfn when removing pages from zone David Hildenbrand 2019-09-26 12:43 ` David Hildenbrand 2019-09-26 13:15 ` Aneesh Kumar K.V 2019-09-26 13:15 ` Aneesh Kumar K.V 2019-09-26 13:34 ` Pankaj Gupta 2019-09-26 13:34 ` Pankaj Gupta 2019-09-26 22:45 ` Andrew Morton 2019-09-26 22:45 ` Andrew Morton 2019-09-27 1:51 ` Aneesh Kumar K.V 2019-09-27 1:51 ` Aneesh Kumar K.V 2019-09-27 7:46 ` David Hildenbrand 2019-09-27 7:46 ` David Hildenbrand 2019-09-27 10:32 ` [PATCH] " Aneesh Kumar K.V 2019-09-27 10:32 ` Aneesh Kumar K.V 2019-09-27 10:38 ` David Hildenbrand 2019-09-27 10:38 ` David Hildenbrand 2019-09-27 10:36 ` [PATCH 1/2] " Aneesh Kumar K.V 2019-09-27 10:36 ` Aneesh Kumar K.V 2019-09-27 10:40 ` David Hildenbrand 2019-09-27 10:40 ` David Hildenbrand 2019-09-27 11:35 ` Aneesh Kumar K.V 2019-09-27 11:35 ` Aneesh Kumar K.V 2019-09-27 11:38 ` David Hildenbrand 2019-09-27 11:38 ` David Hildenbrand
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