{"id":819217,"url":"http://patchwork.ozlabs.org/api/patches/819217/?format=json","web_url":"http://patchwork.ozlabs.org/project/ubuntu-kernel/patch/7622ee313f20fbae58cfa0b880f9d27dd1a9a10b.1506525800.git.joseph.salisbury@canonical.com/","project":{"id":15,"url":"http://patchwork.ozlabs.org/api/projects/15/?format=json","name":"Ubuntu Kernel","link_name":"ubuntu-kernel","list_id":"kernel-team.lists.ubuntu.com","list_email":"kernel-team@lists.ubuntu.com","web_url":null,"scm_url":null,"webscm_url":null,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<7622ee313f20fbae58cfa0b880f9d27dd1a9a10b.1506525800.git.joseph.salisbury@canonical.com>","list_archive_url":null,"date":"2017-09-27T15:32:41","name":"[SRU,Zesty,1/1] powerpc/64s: Handle data breakpoints in Radix mode","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"233ab8cb770e4c93c279f025fca69063ad13bd8f","submitter":{"id":7793,"url":"http://patchwork.ozlabs.org/api/people/7793/?format=json","name":"Joseph Salisbury","email":"joseph.salisbury@canonical.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/ubuntu-kernel/patch/7622ee313f20fbae58cfa0b880f9d27dd1a9a10b.1506525800.git.joseph.salisbury@canonical.com/mbox/","series":[{"id":5393,"url":"http://patchwork.ozlabs.org/api/series/5393/?format=json","web_url":"http://patchwork.ozlabs.org/project/ubuntu-kernel/list/?series=5393","date":"2017-09-27T15:32:40","name":"powerpc/64s: Handle data breakpoints in Radix mode","version":1,"mbox":"http://patchwork.ozlabs.org/series/5393/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/819217/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/819217/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":"ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=lists.ubuntu.com\n\t(client-ip=91.189.94.19; helo=huckleberry.canonical.com;\n\tenvelope-from=kernel-team-bounces@lists.ubuntu.com;\n\treceiver=)","Received":["from huckleberry.canonical.com (huckleberry.canonical.com\n\t[91.189.94.19])\n\tby ozlabs.org (Postfix) with ESMTP id 3y2MLH3fqwz9tXy;\n\tThu, 28 Sep 2017 01:33:59 +1000 (AEST)","from localhost ([127.0.0.1] helo=huckleberry.canonical.com)\n\tby huckleberry.canonical.com with esmtp (Exim 4.86_2)\n\t(envelope-from )\n\tid 1dxELS-0000Cv-R0; Wed, 27 Sep 2017 15:33:54 +0000","from youngberry.canonical.com ([91.189.89.112])\n\tby huckleberry.canonical.com with esmtps\n\t(TLS1.0:DHE_RSA_AES_128_CBC_SHA1:128)\n\t(Exim 4.86_2) (envelope-from )\n\tid 1dxELQ-0000Bo-AN\n\tfor kernel-team@lists.ubuntu.com; Wed, 27 Sep 2017 15:33:52 +0000","from 1.general.jsalisbury.us.vpn ([10.172.67.212] helo=salisbury)\n\tby youngberry.canonical.com with esmtpsa\n\t(TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32)\n\t(Exim 4.76) (envelope-from )\n\tid 1dxEKI-0000ws-Ha\n\tfor kernel-team@lists.ubuntu.com; Wed, 27 Sep 2017 15:32:42 +0000","by salisbury (Postfix, from userid 1000)\n\tid B12027E28AE; Wed, 27 Sep 2017 11:32:41 -0400 (EDT)"],"From":"Joseph Salisbury ","To":"kernel-team@lists.ubuntu.com","Subject":"[SRU][Zesty][PATCH 1/1] powerpc/64s: Handle data breakpoints in\n\tRadix mode","Date":"Wed, 27 Sep 2017 11:32:41 -0400","Message-Id":"<7622ee313f20fbae58cfa0b880f9d27dd1a9a10b.1506525800.git.joseph.salisbury@canonical.com>","X-Mailer":"git-send-email 2.7.4","In-Reply-To":["",""],"References":["",""],"X-BeenThere":"kernel-team@lists.ubuntu.com","X-Mailman-Version":"2.1.20","Precedence":"list","List-Id":"Kernel team discussions ","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","MIME-Version":"1.0","Content-Type":"text/plain; charset=\"utf-8\"","Content-Transfer-Encoding":"base64","Errors-To":"kernel-team-bounces@lists.ubuntu.com","Sender":"\"kernel-team\" "},"content":"From: \"Naveen N. Rao\" \n\nBugLink: http://bugs.launchpad.net/bugs/1706033\n\nOn Power9, trying to use data breakpoints throws the splat shown\nbelow. This is because the check for a data breakpoint in DSISR is in\ndo_hash_page(), which is not called when in Radix mode.\n\n Unable to handle kernel paging request for data at address 0xc000000000e19218\n Faulting instruction address: 0xc0000000001155e8\n cpu 0x0: Vector: 300 (Data Access) at [c0000000ef1e7b20]\n pc: c0000000001155e8: find_pid_ns+0x48/0xe0\n lr: c000000000116ac4: find_task_by_vpid+0x44/0x90\n sp: c0000000ef1e7da0\n msr: 9000000000009033\n dar: c000000000e19218\n dsisr: 400000\n\nMove the check to handle_page_fault() so as to catch data breakpoints\nin both Hash and Radix MMU modes.\n\nWe have to change the check in do_hash_page() against 0xa410 to use\n0xa450, so as to include the value of (DSISR_DABRMATCH << 16).\n\nThere are two sites that call handle_page_fault() when in Radix, both\nalready pass DSISR in r4.\n\nFixes: caca285e5ab4 (\"powerpc/mm/radix: Use STD_MMU_64 to properly isolate hash related code\")\nCc: stable@vger.kernel.org # v4.7+\nReported-by: Shriya R. Kulkarni \nSigned-off-by: Naveen N. Rao \n[mpe: Fix the fall-through case on hash, we need to reload DSISR]\nSigned-off-by: Michael Ellerman \n\n(cherry picked from commit d89ba5353f301971dd7d2f9fdf25c4432728f38e)\nSigned-off-by: Joseph Salisbury \n---\n arch/powerpc/kernel/exceptions-64s.S | 11 +++++++----\n 1 file changed, 7 insertions(+), 4 deletions(-)","diff":"diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S\nindex 7845613..fa2c6c9 100644\n--- a/arch/powerpc/kernel/exceptions-64s.S\n+++ b/arch/powerpc/kernel/exceptions-64s.S\n@@ -1418,10 +1418,8 @@ USE_TEXT_SECTION()\n \t.balign\tIFETCH_ALIGN_BYTES\n do_hash_page:\n #ifdef CONFIG_PPC_STD_MMU_64\n-\tandis.\tr0,r4,0xa410\t\t/* weird error? */\n+\tandis.\tr0,r4,0xa450\t\t/* weird error? */\n \tbne-\thandle_page_fault\t/* if not, try to insert a HPTE */\n-\tandis. r0,r4,DSISR_DABRMATCH@h\n-\tbne- handle_dabr_fault\n \tCURRENT_THREAD_INFO(r11, r1)\n \tlwz\tr0,TI_PREEMPT(r11)\t/* If we're in an \"NMI\" */\n \tandis.\tr0,r0,NMI_MASK@h\t/* (i.e. an irq when soft-disabled) */\n@@ -1445,11 +1443,16 @@ do_hash_page:\n \n \t/* Error */\n \tblt-\t13f\n+\n+\t/* Reload DSISR into r4 for the DABR check below */\n+\tld r4,_DSISR(r1)\n #endif /* CONFIG_PPC_STD_MMU_64 */\n \n /* Here we have a page fault that hash_page can't handle. */\n handle_page_fault:\n-11:\tld\tr4,_DAR(r1)\n+11:\tandis. r0,r4,DSISR_DABRMATCH@h\n+\tbne- handle_dabr_fault\n+\tld\tr4,_DAR(r1)\n \tld\tr5,_DSISR(r1)\n \taddi\tr3,r1,STACK_FRAME_OVERHEAD\n \tbl\tdo_page_fault\n","prefixes":["SRU","Zesty","1/1"]}