Patch Detail
get:
Show a patch.
patch:
Update a patch.
put:
Update a patch.
GET /api/patches/811778/?format=api
{ "id": 811778, "url": "http://patchwork.ozlabs.org/api/patches/811778/?format=api", "web_url": "http://patchwork.ozlabs.org/project/linuxppc-dev/patch/1504894024-2750-3-git-send-email-ldufour@linux.vnet.ibm.com/", "project": { "id": 2, "url": "http://patchwork.ozlabs.org/api/projects/2/?format=api", "name": "Linux PPC development", "link_name": "linuxppc-dev", "list_id": "linuxppc-dev.lists.ozlabs.org", "list_email": "linuxppc-dev@lists.ozlabs.org", "web_url": "https://github.com/linuxppc/wiki/wiki", "scm_url": "https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git", "webscm_url": "https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/", "list_archive_url": "https://lore.kernel.org/linuxppc-dev/", "list_archive_url_format": "https://lore.kernel.org/linuxppc-dev/{}/", "commit_url_format": "https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?id={}" }, "msgid": "<1504894024-2750-3-git-send-email-ldufour@linux.vnet.ibm.com>", "list_archive_url": "https://lore.kernel.org/linuxppc-dev/1504894024-2750-3-git-send-email-ldufour@linux.vnet.ibm.com/", "date": "2017-09-08T18:06:46", "name": "[v3,02/20] mm: Prepare for FAULT_FLAG_SPECULATIVE", "commit_ref": null, "pull_url": null, "state": "not-applicable", "archived": false, "hash": "37d1c51d2b3a4c5b1e4843a38b814b660fa3a2d5", "submitter": { "id": 40248, "url": "http://patchwork.ozlabs.org/api/people/40248/?format=api", "name": "Laurent Dufour", "email": "ldufour@linux.vnet.ibm.com" }, "delegate": null, "mbox": "http://patchwork.ozlabs.org/project/linuxppc-dev/patch/1504894024-2750-3-git-send-email-ldufour@linux.vnet.ibm.com/mbox/", "series": [ { "id": 2269, "url": "http://patchwork.ozlabs.org/api/series/2269/?format=api", "web_url": "http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=2269", "date": "2017-09-08T18:06:44", "name": "Speculative page faults", "version": 3, "mbox": "http://patchwork.ozlabs.org/series/2269/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/patches/811778/comments/", "check": "pending", "checks": "http://patchwork.ozlabs.org/api/patches/811778/checks/", "tags": {}, "related": [], "headers": { "Return-Path": "<linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org>", "X-Original-To": [ "patchwork-incoming@ozlabs.org", "linuxppc-dev@lists.ozlabs.org" ], "Delivered-To": [ "patchwork-incoming@ozlabs.org", "linuxppc-dev@lists.ozlabs.org" ], "Received": [ "from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3])\n\t(using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3xplpd0zmZz9ryk\n\tfor <patchwork-incoming@ozlabs.org>;\n\tSat, 9 Sep 2017 04:14:49 +1000 (AEST)", "from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3])\n\tby lists.ozlabs.org (Postfix) with ESMTP id 3xplpc73sZzDqY8\n\tfor <patchwork-incoming@ozlabs.org>;\n\tSat, 9 Sep 2017 04:14:48 +1000 (AEST)", "from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com\n\t[148.163.156.1])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256\n\tbits)) (No client certificate requested)\n\tby lists.ozlabs.org (Postfix) with ESMTPS id 3xplf52hfrzDrVj\n\tfor <linuxppc-dev@lists.ozlabs.org>;\n\tSat, 9 Sep 2017 04:07:24 +1000 (AEST)", "from pps.filterd (m0098409.ppops.net [127.0.0.1])\n\tby mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id\n\tv88I7F9t104866\n\tfor <linuxppc-dev@lists.ozlabs.org>; Fri, 8 Sep 2017 14:07:23 -0400", "from e06smtp13.uk.ibm.com (e06smtp13.uk.ibm.com [195.75.94.109])\n\tby mx0a-001b2d01.pphosted.com with ESMTP id 2cuys51407-1\n\t(version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT)\n\tfor <linuxppc-dev@lists.ozlabs.org>; Fri, 08 Sep 2017 14:07:23 -0400", "from localhost\n\tby e06smtp13.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use\n\tOnly! Violators will be prosecuted\n\tfor <linuxppc-dev@lists.ozlabs.org> from <ldufour@linux.vnet.ibm.com>;\n\tFri, 8 Sep 2017 19:07:20 +0100", "from b06cxnps3074.portsmouth.uk.ibm.com (9.149.109.194)\n\tby e06smtp13.uk.ibm.com (192.168.101.143) with IBM ESMTP SMTP\n\tGateway: Authorized Use Only! Violators will be prosecuted; \n\tFri, 8 Sep 2017 19:07:14 +0100", "from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com\n\t[9.149.105.60])\n\tby b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with\n\tESMTP id v88I7DKg24838164; Fri, 8 Sep 2017 18:07:13 GMT", "from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id AEF9A4203F;\n\tFri, 8 Sep 2017 19:03:40 +0100 (BST)", "from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id 888A842041;\n\tFri, 8 Sep 2017 19:03:38 +0100 (BST)", "from nimbus.lab.toulouse-stg.fr.ibm.com (unknown [9.145.31.125])\n\tby d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP;\n\tFri, 8 Sep 2017 19:03:38 +0100 (BST)" ], "Authentication-Results": "ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=linux.vnet.ibm.com\n\t(client-ip=148.163.156.1; helo=mx0a-001b2d01.pphosted.com;\n\tenvelope-from=ldufour@linux.vnet.ibm.com; receiver=<UNKNOWN>)", "From": "Laurent Dufour <ldufour@linux.vnet.ibm.com>", "To": "paulmck@linux.vnet.ibm.com, peterz@infradead.org,\n\takpm@linux-foundation.org, kirill@shutemov.name, ak@linux.intel.com, \n\tmhocko@kernel.org, dave@stgolabs.net, jack@suse.cz,\n\tMatthew Wilcox <willy@infradead.org>, benh@kernel.crashing.org,\n\tmpe@ellerman.id.au, paulus@samba.org,\n\tThomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, \n\thpa@zytor.com, Will Deacon <will.deacon@arm.com>,\n\tSergey Senozhatsky <sergey.senozhatsky@gmail.com>", "Subject": "[PATCH v3 02/20] mm: Prepare for FAULT_FLAG_SPECULATIVE", "Date": "Fri, 8 Sep 2017 20:06:46 +0200", "X-Mailer": "git-send-email 2.7.4", "In-Reply-To": "<1504894024-2750-1-git-send-email-ldufour@linux.vnet.ibm.com>", "References": "<1504894024-2750-1-git-send-email-ldufour@linux.vnet.ibm.com>", "X-TM-AS-GCONF": "00", "x-cbid": "17090818-0012-0000-0000-00000577A9A4", "X-IBM-AV-DETECTION": "SAVI=unused REMOTE=unused XFE=unused", "x-cbparentid": "17090818-0013-0000-0000-000018F0B120", "Message-Id": "<1504894024-2750-3-git-send-email-ldufour@linux.vnet.ibm.com>", "X-Proofpoint-Virus-Version": "vendor=fsecure engine=2.50.10432:, ,\n\tdefinitions=2017-09-08_12:, , signatures=0", "X-Proofpoint-Spam-Details": "rule=outbound_notspam policy=outbound score=0\n\tspamscore=0 suspectscore=2\n\tmalwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam\n\tadjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000\n\tdefinitions=main-1709080270", "X-BeenThere": "linuxppc-dev@lists.ozlabs.org", "X-Mailman-Version": "2.1.23", "Precedence": "list", "List-Id": "Linux on PowerPC Developers Mail List\n\t<linuxppc-dev.lists.ozlabs.org>", "List-Unsubscribe": "<https://lists.ozlabs.org/options/linuxppc-dev>,\n\t<mailto:linuxppc-dev-request@lists.ozlabs.org?subject=unsubscribe>", "List-Archive": "<http://lists.ozlabs.org/pipermail/linuxppc-dev/>", "List-Post": "<mailto:linuxppc-dev@lists.ozlabs.org>", "List-Help": "<mailto:linuxppc-dev-request@lists.ozlabs.org?subject=help>", "List-Subscribe": "<https://lists.ozlabs.org/listinfo/linuxppc-dev>,\n\t<mailto:linuxppc-dev-request@lists.ozlabs.org?subject=subscribe>", "Cc": "linuxppc-dev@lists.ozlabs.org, x86@kernel.org,\n\tlinux-kernel@vger.kernel.org, npiggin@gmail.com, linux-mm@kvack.org,\n\tTim Chen <tim.c.chen@linux.intel.com>, \n\tharen@linux.vnet.ibm.com, khandual@linux.vnet.ibm.com", "Errors-To": "linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org", "Sender": "\"Linuxppc-dev\"\n\t<linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org>" }, "content": "From: Peter Zijlstra <peterz@infradead.org>\n\nWhen speculating faults (without holding mmap_sem) we need to validate\nthat the vma against which we loaded pages is still valid when we're\nready to install the new PTE.\n\nTherefore, replace the pte_offset_map_lock() calls that (re)take the\nPTL with pte_map_lock() which can fail in case we find the VMA changed\nsince we started the fault.\n\nSigned-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>\n\n[Port to 4.12 kernel]\n[Remove the comment about the fault_env structure which has been\n implemented as the vm_fault structure in the kernel]\nSigned-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>\n---\n include/linux/mm.h | 1 +\n mm/memory.c | 55 ++++++++++++++++++++++++++++++++++++++----------------\n 2 files changed, 40 insertions(+), 16 deletions(-)", "diff": "diff --git a/include/linux/mm.h b/include/linux/mm.h\nindex 68be41b31ad0..46e769a5a7ab 100644\n--- a/include/linux/mm.h\n+++ b/include/linux/mm.h\n@@ -291,6 +291,7 @@ extern pgprot_t protection_map[16];\n #define FAULT_FLAG_USER\t\t0x40\t/* The fault originated in userspace */\n #define FAULT_FLAG_REMOTE\t0x80\t/* faulting for non current tsk/mm */\n #define FAULT_FLAG_INSTRUCTION 0x100\t/* The fault was during an instruction fetch */\n+#define FAULT_FLAG_SPECULATIVE\t0x200\t/* Speculative fault, not holding mmap_sem */\n \n #define FAULT_FLAG_TRACE \\\n \t{ FAULT_FLAG_WRITE,\t\t\"WRITE\" }, \\\ndiff --git a/mm/memory.c b/mm/memory.c\nindex 30bccfa00630..13c8c3c8b5e4 100644\n--- a/mm/memory.c\n+++ b/mm/memory.c\n@@ -2408,6 +2408,12 @@ static inline void wp_page_reuse(struct vm_fault *vmf)\n \tpte_unmap_unlock(vmf->pte, vmf->ptl);\n }\n \n+static bool pte_map_lock(struct vm_fault *vmf)\n+{\n+\tvmf->pte = pte_offset_map_lock(vmf->vma->vm_mm, vmf->pmd, vmf->address, &vmf->ptl);\n+\treturn true;\n+}\n+\n /*\n * Handle the case of a page which we actually need to copy to a new page.\n *\n@@ -2435,6 +2441,7 @@ static int wp_page_copy(struct vm_fault *vmf)\n \tconst unsigned long mmun_start = vmf->address & PAGE_MASK;\n \tconst unsigned long mmun_end = mmun_start + PAGE_SIZE;\n \tstruct mem_cgroup *memcg;\n+\tint ret = VM_FAULT_OOM;\n \n \tif (unlikely(anon_vma_prepare(vma)))\n \t\tgoto oom;\n@@ -2462,7 +2469,11 @@ static int wp_page_copy(struct vm_fault *vmf)\n \t/*\n \t * Re-check the pte - we dropped the lock\n \t */\n-\tvmf->pte = pte_offset_map_lock(mm, vmf->pmd, vmf->address, &vmf->ptl);\n+\tif (!pte_map_lock(vmf)) {\n+\t\tmem_cgroup_cancel_charge(new_page, memcg, false);\n+\t\tret = VM_FAULT_RETRY;\n+\t\tgoto oom_free_new;\n+\t}\n \tif (likely(pte_same(*vmf->pte, vmf->orig_pte))) {\n \t\tif (old_page) {\n \t\t\tif (!PageAnon(old_page)) {\n@@ -2550,7 +2561,7 @@ static int wp_page_copy(struct vm_fault *vmf)\n oom:\n \tif (old_page)\n \t\tput_page(old_page);\n-\treturn VM_FAULT_OOM;\n+\treturn ret;\n }\n \n /**\n@@ -2571,8 +2582,8 @@ static int wp_page_copy(struct vm_fault *vmf)\n int finish_mkwrite_fault(struct vm_fault *vmf)\n {\n \tWARN_ON_ONCE(!(vmf->vma->vm_flags & VM_SHARED));\n-\tvmf->pte = pte_offset_map_lock(vmf->vma->vm_mm, vmf->pmd, vmf->address,\n-\t\t\t\t &vmf->ptl);\n+\tif (!pte_map_lock(vmf))\n+\t\treturn VM_FAULT_RETRY;\n \t/*\n \t * We might have raced with another page fault while we released the\n \t * pte_offset_map_lock.\n@@ -2690,8 +2701,11 @@ static int do_wp_page(struct vm_fault *vmf)\n \t\t\tget_page(vmf->page);\n \t\t\tpte_unmap_unlock(vmf->pte, vmf->ptl);\n \t\t\tlock_page(vmf->page);\n-\t\t\tvmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd,\n-\t\t\t\t\tvmf->address, &vmf->ptl);\n+\t\t\tif (!pte_map_lock(vmf)) {\n+\t\t\t\tunlock_page(vmf->page);\n+\t\t\t\tput_page(vmf->page);\n+\t\t\t\treturn VM_FAULT_RETRY;\n+\t\t\t}\n \t\t\tif (!pte_same(*vmf->pte, vmf->orig_pte)) {\n \t\t\t\tunlock_page(vmf->page);\n \t\t\t\tpte_unmap_unlock(vmf->pte, vmf->ptl);\n@@ -2868,8 +2882,10 @@ int do_swap_page(struct vm_fault *vmf)\n \t\t\t * Back out if somebody else faulted in this pte\n \t\t\t * while we released the pte lock.\n \t\t\t */\n-\t\t\tvmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd,\n-\t\t\t\t\tvmf->address, &vmf->ptl);\n+\t\t\tif (!pte_map_lock(vmf)) {\n+\t\t\t\tdelayacct_clear_flag(DELAYACCT_PF_SWAPIN);\n+\t\t\t\treturn VM_FAULT_RETRY;\n+\t\t\t}\n \t\t\tif (likely(pte_same(*vmf->pte, vmf->orig_pte)))\n \t\t\t\tret = VM_FAULT_OOM;\n \t\t\tdelayacct_clear_flag(DELAYACCT_PF_SWAPIN);\n@@ -2925,8 +2941,11 @@ int do_swap_page(struct vm_fault *vmf)\n \t/*\n \t * Back out if somebody else already faulted in this pte.\n \t */\n-\tvmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address,\n-\t\t\t&vmf->ptl);\n+\tif (!pte_map_lock(vmf)) {\n+\t\tret = VM_FAULT_RETRY;\n+\t\tmem_cgroup_cancel_charge(page, memcg, false);\n+\t\tgoto out_page;\n+\t}\n \tif (unlikely(!pte_same(*vmf->pte, vmf->orig_pte)))\n \t\tgoto out_nomap;\n \n@@ -3053,8 +3072,8 @@ static int do_anonymous_page(struct vm_fault *vmf)\n \t\t\t!mm_forbids_zeropage(vma->vm_mm)) {\n \t\tentry = pte_mkspecial(pfn_pte(my_zero_pfn(vmf->address),\n \t\t\t\t\t\tvma->vm_page_prot));\n-\t\tvmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd,\n-\t\t\t\tvmf->address, &vmf->ptl);\n+\t\tif (!pte_map_lock(vmf))\n+\t\t\treturn VM_FAULT_RETRY;\n \t\tif (!pte_none(*vmf->pte))\n \t\t\tgoto unlock;\n \t\tret = check_stable_address_space(vma->vm_mm);\n@@ -3089,8 +3108,11 @@ static int do_anonymous_page(struct vm_fault *vmf)\n \tif (vma->vm_flags & VM_WRITE)\n \t\tentry = pte_mkwrite(pte_mkdirty(entry));\n \n-\tvmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address,\n-\t\t\t&vmf->ptl);\n+\tif (!pte_map_lock(vmf)) {\n+\t\tmem_cgroup_cancel_charge(page, memcg, false);\n+\t\tput_page(page);\n+\t\treturn VM_FAULT_RETRY;\n+\t}\n \tif (!pte_none(*vmf->pte))\n \t\tgoto release;\n \n@@ -3214,8 +3236,9 @@ static int pte_alloc_one_map(struct vm_fault *vmf)\n \t * pte_none() under vmf->ptl protection when we return to\n \t * alloc_set_pte().\n \t */\n-\tvmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address,\n-\t\t\t&vmf->ptl);\n+\tif (!pte_map_lock(vmf))\n+\t\treturn VM_FAULT_RETRY;\n+\n \treturn 0;\n }\n \n", "prefixes": [ "v3", "02/20" ] }