From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx485qXjLYn7rqOIWtu5m5KQKCZQ17Bn3EHf1hfvfIN5zr/ghJcX2BVYUX/oZDTosLqchPuYo ARC-Seal: i=1; a=rsa-sha256; t=1523022150; cv=none; d=google.com; s=arc-20160816; b=1It7boUoGJUGrP7bJWu47sz5swUdFY/MT0PM8lb6yMidctwnjUPHjBAP66qqTGE+KR qL2Xf+0uF3LMJZqCLnEcng7jGx54lFu9eMylGLxHVf5ssZ0Of1J30KM4KEMt7XPLCRIP soKTiZY4MJQNoSiD6wm1ZzH6seiyN6ElTbE4IEqW0rmEeTZdOGwdcLM780sicRdP6FS/ N69iQaOHhP6ibjCmJq/RG03tUY7mLKJGETwUX573SBiRpfm4wHb63mCVWNREYDPwor7A Q/VABYDm0udubyycI+eW6lokzJyfiFqxaVtRC/Qf0V7ba3PzTLj213R9rZi3ys7SwLNJ eEmg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=ia6k1I8n668hnHD3OTrUNhpku4FwYs4LbWEGE9oNcRA=; b=JvVPyj/yC5ECXT30dqvRUu5zi0/HukhH6UCBhoJmZEUO5Fw0RRrfRMREHKotrwNJcb q5j/gJUrVolZhyYUu2tgXIlZJndSYSbLUIb3n7DjoqbKPFDKCkeQKolZmMT8BiFwuvm6 uZwF1LzcEZ3byCR5yWcKyxbjfryG4nu76KP8hUHXFpG0B0LfGTpQnS3Te004W3QPxJTB qexNdOnH2pF7UHu9uSGyDA50hWqHbAulUC1A/taqp9OmAa+kxTXb+EiEjuQ4nKqI26LW XfpfFFY243phiPgTCBNuPcZ1i8ZGVWeU8XrOrZANfW/3MDyHmcpo4NoP44Qf6zeJeu/1 x0rA== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nicholas Piggin , Michael Ellerman Subject: [PATCH 4.15 18/72] powerpc/64s: Fix i-side SLB miss bad address handler saving nonvolatile GPRs Date: Fri, 6 Apr 2018 15:23:53 +0200 Message-Id: <20180406084350.948403208@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180406084349.367583460@linuxfoundation.org> References: <20180406084349.367583460@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1597003860218571411?= X-GMAIL-MSGID: =?utf-8?q?1597004475095929178?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nicholas Piggin commit 52396500f97c53860164debc7d4f759077853423 upstream. The SLB bad address handler's trap number fixup does not preserve the low bit that indicates nonvolatile GPRs have not been saved. This leads save_nvgprs to skip saving them, and subsequent functions and return from interrupt will think they are saved. This causes kernel branch-to-garbage debugging to not have correct registers, can also cause userspace to have its registers clobbered after a segfault. Fixes: f0f558b131db ("powerpc/mm: Preserve CFAR value on SLB miss caused by access to bogus address") Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/exceptions-64s.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -706,7 +706,7 @@ EXC_COMMON_BEGIN(bad_addr_slb) ld r3, PACA_EXSLB+EX_DAR(r13) std r3, _DAR(r1) beq cr6, 2f - li r10, 0x480 /* fix trap number for I-SLB miss */ + li r10, 0x481 /* fix trap number for I-SLB miss */ std r10, _TRAP(r1) 2: bl save_nvgprs addi r3, r1, STACK_FRAME_OVERHEAD