From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 416bwQ4WhqzF1LY for ; Fri, 15 Jun 2018 20:15:34 +1000 (AEST) Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w5FADoEF120489 for ; Fri, 15 Jun 2018 06:15:31 -0400 Received: from e12.ny.us.ibm.com (e12.ny.us.ibm.com [129.33.205.202]) by mx0a-001b2d01.pphosted.com with ESMTP id 2jm99dwht8-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 15 Jun 2018 06:15:31 -0400 Received: from localhost by e12.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 15 Jun 2018 06:15:30 -0400 Subject: Re: [PATCH] powerpc/mm: Fix kernel crash on page table free To: Christophe Leroy , benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au Cc: linuxppc-dev@lists.ozlabs.org References: <20180530123225.7732-1-aneesh.kumar@linux.ibm.com> <1bbbfc4d-c47c-2383-454c-430a014beb9e@c-s.fr> From: "Aneesh Kumar K.V" Date: Fri, 15 Jun 2018 15:45:23 +0530 MIME-Version: 1.0 In-Reply-To: <1bbbfc4d-c47c-2383-454c-430a014beb9e@c-s.fr> Content-Type: text/plain; charset=utf-8; format=flowed Message-Id: <186c9af6-17d1-d28f-a53c-3bf58d69ada1@linux.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 06/15/2018 03:24 AM, Christophe Leroy wrote: > > > On 05/30/2018 12:32 PM, Aneesh Kumar K.V wrote: >> Fix the below crash on BookE 64. pgtable_page_dtor expects struct page >> *arg. >> >> Also call the destructor on non book3s platforms correctly. This free >> up the >> split ptl locks correctly if we had allocated them before. >> >> Call Trace: >> [c0000000f30c7520] [c00000000021eeec] .kmem_cache_free+0x9c/0x44c >> (unreliable) >> [c0000000f30c75c0] [c0000000001ee07c] .ptlock_free+0x1c/0x30 >> [c0000000f30c7630] [c0000000001ee260] .tlb_remove_table+0xdc/0x224 >> [c0000000f30c76c0] [c0000000001ee640] .free_pgd_range+0x298/0x500 >> [c0000000f30c77d0] [c000000000232afc] .shift_arg_pages+0x10c/0x1e0 >> [c0000000f30c7910] [c000000000232dd0] .setup_arg_pages+0x200/0x25c >> [c0000000f30c79c0] [c0000000002ad4fc] .load_elf_binary+0x450/0x16c8 >> [c0000000f30c7b10] [c000000000234914] >> .search_binary_handler.part.11+0x9c/0x248 >> [c0000000f30c7bb0] [c00000000023595c] >> .do_execveat_common.isra.13+0x868/0xc18 >> [c0000000f30c7cb0] [c00000000000184c] .run_init_process+0x34/0x4c >> [c0000000f30c7d30] [c000000000001880] .try_to_run_init_process+0x1c/0x68 >> [c0000000f30c7db0] [c000000000002bd8] .kernel_init+0xdc/0x130 >> [c0000000f30c7e30] [c0000000000009dc] .ret_from_kernel_thread+0x58/0x7c >> >> Fixes: 702346768 ("powerpc/mm/nohash: Remove pte fragment dependency >> from nohash") >> Signed-off-by: Aneesh Kumar K.V >> --- >>   arch/powerpc/include/asm/book3s/32/pgalloc.h | 1 + >>   arch/powerpc/include/asm/nohash/32/pgalloc.h | 1 + >>   arch/powerpc/include/asm/nohash/64/pgalloc.h | 2 +- >>   3 files changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/arch/powerpc/include/asm/book3s/32/pgalloc.h >> b/arch/powerpc/include/asm/book3s/32/pgalloc.h >> index 5073cc75f1c8..6a6673907e45 100644 >> --- a/arch/powerpc/include/asm/book3s/32/pgalloc.h >> +++ b/arch/powerpc/include/asm/book3s/32/pgalloc.h >> @@ -99,6 +99,7 @@ static inline void pte_free(struct mm_struct *mm, >> pgtable_t ptepage) >>   static inline void pgtable_free(void *table, unsigned index_size) >>   { >>       if (!index_size) { >> +        pgtable_page_dtor(virt_to_page(table)); > > __pte_free_tlb() already calls pgtable_page_dtor(table) before calling > pgtable_free() via pgtable_free_tlb(). > > Is it normal to call it twice ? No. We should call pgtable_page_dtor only in the rcu callback. So we should remove it from __pte_free_tlb(). > >>           free_page((unsigned long)table); >>       } else { >>           BUG_ON(index_size > MAX_PGTABLE_INDEX_SIZE); >> diff --git a/arch/powerpc/include/asm/nohash/32/pgalloc.h >> b/arch/powerpc/include/asm/nohash/32/pgalloc.h >> index 29d37bd1f3b3..1707781d2f20 100644 >> --- a/arch/powerpc/include/asm/nohash/32/pgalloc.h >> +++ b/arch/powerpc/include/asm/nohash/32/pgalloc.h >> @@ -100,6 +100,7 @@ static inline void pte_free(struct mm_struct *mm, >> pgtable_t ptepage) >>   static inline void pgtable_free(void *table, unsigned index_size) >>   { >>       if (!index_size) { >> +        pgtable_page_dtor(virt_to_page(table)); > > Same here I don't have the facility to test anything other than book3s64. Can you do a patch for this? -aneesh