From: Vlastimil Babka <vbabka@suse.cz> To: Hui Zhu <zhuhui@xiaomi.com>, akpm@linux-foundation.org, iamjoonsoo.kim@lge.com, lauraa@codeaurora.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: teawater@gmail.com Subject: Re: [PATCH v2] CMA: page_isolation: check buddy before access it Date: Tue, 05 May 2015 10:43:42 +0200 [thread overview] Message-ID: <554882BE.5020804@suse.cz> (raw) In-Reply-To: <1430796179-1795-1-git-send-email-zhuhui@xiaomi.com> On 05/05/2015 05:22 AM, Hui Zhu wrote: > Change pfn_present to pfn_valid_within according to the review of Laura. > > I got a issue: > [ 214.294917] Unable to handle kernel NULL pointer dereference at virtual address 0000082a > [ 214.303013] pgd = cc970000 > [ 214.305721] [0000082a] *pgd=00000000 > [ 214.309316] Internal error: Oops: 5 [#1] PREEMPT SMP ARM > [ 214.335704] PC is at get_pageblock_flags_group+0x5c/0xb0 > [ 214.341030] LR is at unset_migratetype_isolate+0x148/0x1b0 > [ 214.346523] pc : [<c00cc9a0>] lr : [<c0109874>] psr: 80000093 > [ 214.346523] sp : c7029d00 ip : 00000105 fp : c7029d1c > [ 214.358005] r10: 00000001 r9 : 0000000a r8 : 00000004 > [ 214.363231] r7 : 60000013 r6 : 000000a4 r5 : c0a357e4 r4 : 00000000 > [ 214.369761] r3 : 00000826 r2 : 00000002 r1 : 00000000 r0 : 0000003f > [ 214.376291] Flags: Nzcv IRQs off FIQs on Mode SVC_32 ISA ARM Segment user > [ 214.383516] Control: 10c5387d Table: 2cb7006a DAC: 00000015 > [ 214.949720] Backtrace: > [ 214.952192] [<c00cc944>] (get_pageblock_flags_group+0x0/0xb0) from [<c0109874>] (unset_migratetype_isolate+0x148/0x1b0) > [ 214.962978] r7:60000013 r6:c0a357c0 r5:c0a357e4 r4:c1555000 > [ 214.968693] [<c010972c>] (unset_migratetype_isolate+0x0/0x1b0) from [<c0109adc>] (undo_isolate_page_range+0xd0/0xdc) > [ 214.979222] [<c0109a0c>] (undo_isolate_page_range+0x0/0xdc) from [<c00d097c>] (__alloc_contig_range+0x254/0x34c) > [ 214.989398] r9:000abc00 r8:c7028000 r7:000b1f53 r6:000b3e00 r5:00000005 > r4:c7029db4 > [ 214.997308] [<c00d0728>] (__alloc_contig_range+0x0/0x34c) from [<c00d0a88>] (alloc_contig_range+0x14/0x18) > [ 215.006973] [<c00d0a74>] (alloc_contig_range+0x0/0x18) from [<c0398148>] (dma_alloc_from_contiguous_addr+0x1ac/0x304) > > This issue is because when call unset_migratetype_isolate to unset a part > of CMA memory, it try to access the buddy page to get its status: > if (order >= pageblock_order) { > page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); > buddy_idx = __find_buddy_index(page_idx, order); > buddy = page + (buddy_idx - page_idx); > > if (!is_migrate_isolate_page(buddy)) { > But the begin addr of this part of CMA memory is very close to a part of > memory that is reserved in the boot time (not in buddy system). > So add a check before access it. > > Signed-off-by: Hui Zhu <zhuhui@xiaomi.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> > --- > mm/page_isolation.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/mm/page_isolation.c b/mm/page_isolation.c > index 755a42c..eb22d1f 100644 > --- a/mm/page_isolation.c > +++ b/mm/page_isolation.c > @@ -101,7 +101,8 @@ void unset_migratetype_isolate(struct page *page, unsigned migratetype) > buddy_idx = __find_buddy_index(page_idx, order); > buddy = page + (buddy_idx - page_idx); > > - if (!is_migrate_isolate_page(buddy)) { > + if (!pfn_valid_within(page_to_pfn(buddy)) > + || !is_migrate_isolate_page(buddy)) { > __isolate_free_page(page, order); > kernel_map_pages(page, (1 << order), 1); > set_page_refcounted(page); >
WARNING: multiple messages have this Message-ID (diff)
From: Vlastimil Babka <vbabka@suse.cz> To: Hui Zhu <zhuhui@xiaomi.com>, akpm@linux-foundation.org, iamjoonsoo.kim@lge.com, lauraa@codeaurora.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: teawater@gmail.com Subject: Re: [PATCH v2] CMA: page_isolation: check buddy before access it Date: Tue, 05 May 2015 10:43:42 +0200 [thread overview] Message-ID: <554882BE.5020804@suse.cz> (raw) In-Reply-To: <1430796179-1795-1-git-send-email-zhuhui@xiaomi.com> On 05/05/2015 05:22 AM, Hui Zhu wrote: > Change pfn_present to pfn_valid_within according to the review of Laura. > > I got a issue: > [ 214.294917] Unable to handle kernel NULL pointer dereference at virtual address 0000082a > [ 214.303013] pgd = cc970000 > [ 214.305721] [0000082a] *pgd=00000000 > [ 214.309316] Internal error: Oops: 5 [#1] PREEMPT SMP ARM > [ 214.335704] PC is at get_pageblock_flags_group+0x5c/0xb0 > [ 214.341030] LR is at unset_migratetype_isolate+0x148/0x1b0 > [ 214.346523] pc : [<c00cc9a0>] lr : [<c0109874>] psr: 80000093 > [ 214.346523] sp : c7029d00 ip : 00000105 fp : c7029d1c > [ 214.358005] r10: 00000001 r9 : 0000000a r8 : 00000004 > [ 214.363231] r7 : 60000013 r6 : 000000a4 r5 : c0a357e4 r4 : 00000000 > [ 214.369761] r3 : 00000826 r2 : 00000002 r1 : 00000000 r0 : 0000003f > [ 214.376291] Flags: Nzcv IRQs off FIQs on Mode SVC_32 ISA ARM Segment user > [ 214.383516] Control: 10c5387d Table: 2cb7006a DAC: 00000015 > [ 214.949720] Backtrace: > [ 214.952192] [<c00cc944>] (get_pageblock_flags_group+0x0/0xb0) from [<c0109874>] (unset_migratetype_isolate+0x148/0x1b0) > [ 214.962978] r7:60000013 r6:c0a357c0 r5:c0a357e4 r4:c1555000 > [ 214.968693] [<c010972c>] (unset_migratetype_isolate+0x0/0x1b0) from [<c0109adc>] (undo_isolate_page_range+0xd0/0xdc) > [ 214.979222] [<c0109a0c>] (undo_isolate_page_range+0x0/0xdc) from [<c00d097c>] (__alloc_contig_range+0x254/0x34c) > [ 214.989398] r9:000abc00 r8:c7028000 r7:000b1f53 r6:000b3e00 r5:00000005 > r4:c7029db4 > [ 214.997308] [<c00d0728>] (__alloc_contig_range+0x0/0x34c) from [<c00d0a88>] (alloc_contig_range+0x14/0x18) > [ 215.006973] [<c00d0a74>] (alloc_contig_range+0x0/0x18) from [<c0398148>] (dma_alloc_from_contiguous_addr+0x1ac/0x304) > > This issue is because when call unset_migratetype_isolate to unset a part > of CMA memory, it try to access the buddy page to get its status: > if (order >= pageblock_order) { > page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); > buddy_idx = __find_buddy_index(page_idx, order); > buddy = page + (buddy_idx - page_idx); > > if (!is_migrate_isolate_page(buddy)) { > But the begin addr of this part of CMA memory is very close to a part of > memory that is reserved in the boot time (not in buddy system). > So add a check before access it. > > Signed-off-by: Hui Zhu <zhuhui@xiaomi.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> > --- > mm/page_isolation.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/mm/page_isolation.c b/mm/page_isolation.c > index 755a42c..eb22d1f 100644 > --- a/mm/page_isolation.c > +++ b/mm/page_isolation.c > @@ -101,7 +101,8 @@ void unset_migratetype_isolate(struct page *page, unsigned migratetype) > buddy_idx = __find_buddy_index(page_idx, order); > buddy = page + (buddy_idx - page_idx); > > - if (!is_migrate_isolate_page(buddy)) { > + if (!pfn_valid_within(page_to_pfn(buddy)) > + || !is_migrate_isolate_page(buddy)) { > __isolate_free_page(page, order); > kernel_map_pages(page, (1 << order), 1); > set_page_refcounted(page); > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2015-05-05 8:43 UTC|newest] Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-05-04 9:41 [PATCH] CMA: page_isolation: check buddy before access it Hui Zhu 2015-05-04 9:41 ` Hui Zhu 2015-05-04 18:34 ` Laura Abbott 2015-05-04 18:34 ` Laura Abbott 2015-05-05 3:17 ` Hui Zhu 2015-05-05 3:17 ` Hui Zhu 2015-05-05 3:22 ` [PATCH v2] " Hui Zhu 2015-05-05 3:22 ` Hui Zhu 2015-05-05 8:43 ` Vlastimil Babka [this message] 2015-05-05 8:43 ` Vlastimil Babka 2015-05-05 21:29 ` Andrew Morton 2015-05-05 21:29 ` Andrew Morton 2015-05-06 1:39 ` Hui Zhu 2015-05-06 1:39 ` Hui Zhu 2015-05-06 6:28 ` Joonsoo Kim 2015-05-06 6:28 ` Joonsoo Kim 2015-05-06 7:09 ` Hui Zhu 2015-05-06 7:09 ` Hui Zhu 2015-05-06 7:55 ` Vlastimil Babka 2015-05-06 7:55 ` Vlastimil Babka 2015-05-06 7:08 ` [PATCH v3] " Hui Zhu 2015-05-06 7:08 ` Hui Zhu
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=554882BE.5020804@suse.cz \ --to=vbabka@suse.cz \ --cc=akpm@linux-foundation.org \ --cc=iamjoonsoo.kim@lge.com \ --cc=lauraa@codeaurora.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=teawater@gmail.com \ --cc=zhuhui@xiaomi.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.