From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZq+0hzCoz+WxcwODU4n8ozC0+6y+4TLcWY6OtS5QsbAswAUiJMoEiuNI+QPjJ0szYHSlhhr ARC-Seal: i=1; a=rsa-sha256; t=1524838056; cv=none; d=google.com; s=arc-20160816; b=a2hdlVLeXKWkLaKn3EgZO7inKXInmRI0otyXofEZyC4su5W4LKbdDtD5fsuPKKl6Ev 8VshSJv4Oy4CiTNSt3Xfm3k7IxKJhwXtobklZbsLR5n554YdmwQFSUtxReZW3Tqk4jab agHK1vFNJ0jn3O8XTSJVqyvkX49oF3auq+c6Rw5NKe+Vxy5dy3HUiyizB7VdsY7uwBiO HVAMlsmHNzVWj1/sjNmd2wU+V9AhtIQ2Akv3TkumZXvatjWmSDfu5fGlbYD9Ux0hTx8a JrD1f8/fhcrl/brxxsKGTVmyrXlbINHCsaWVl1QgZaM3NJxE9dh3QLEAGCDpOvR9bQUu 9nLA== 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:dmarc-filter:arc-authentication-results; bh=KvGn2Vn50O5K2vYrVyB48glW6JD7kd8HvArGM9v5LmY=; b=XKNowTa3h2BGhtXDkBQAVfmiyirGYb3i/zE3kK0v1yOSsoP0/Xmy/5Bnjgi1eyNH/4 mGbwHFRvdsWZ1JPq0Drq9LG2c4U4WDY9Sh0y2vj4FO4HqR2JnK7ydtPXD3OqPgSiFIN3 McBvMkR6NWMLX7QGxpX1+7xEaQclLLBKnyAvP4fsoac/8EnaNl9UqzTHwAOzR/s3Bu38 juOoeqrBhszeE6xXNtMVCyQJpDY3vDWu+kWyIngbcO8lre4RJJERC4c8YZ4ldktkvQxz U8kEmxkQuTf2G8VzXBes6l2KSyPJgHsK0U+6EbOwZxGgr3OJaiVweEo0n2wprytxWsqe SPvg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of srs0=4/0d=hq=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=4/0d=HQ=linuxfoundation.org=gregkh@kernel.org Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of srs0=4/0d=hq=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=4/0d=HQ=linuxfoundation.org=gregkh@kernel.org DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ED538218D4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=fail smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Martin Schwidefsky , Christian Borntraeger Subject: [PATCH 4.14 45/80] s390: scrub registers on kernel entry and KVM exit Date: Fri, 27 Apr 2018 15:58:38 +0200 Message-Id: <20180427135735.239444417@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180427135732.928644313@linuxfoundation.org> References: <20180427135732.928644313@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?1598908254418187128?= X-GMAIL-MSGID: =?utf-8?q?1598908590048395683?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Martin Schwidefsky [ Upstream commit 7041d28115e91f2144f811ffe8a195c696b1e1d0 ] Clear all user space registers on entry to the kernel and all KVM guest registers on KVM guest exit if the register does not contain either a parameter or a result value. Reviewed-by: Christian Borntraeger Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman --- arch/s390/kernel/entry.S | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -248,6 +248,12 @@ ENTRY(sie64a) sie_exit: lg %r14,__SF_EMPTY+8(%r15) # load guest register save area stmg %r0,%r13,0(%r14) # save guest gprs 0-13 + xgr %r0,%r0 # clear guest registers to + xgr %r1,%r1 # prevent speculative use + xgr %r2,%r2 + xgr %r3,%r3 + xgr %r4,%r4 + xgr %r5,%r5 lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers lg %r2,__SF_EMPTY+16(%r15) # return exit reason code br %r14 @@ -282,6 +288,8 @@ ENTRY(system_call) .Lsysc_vtime: UPDATE_VTIME %r8,%r9,__LC_SYNC_ENTER_TIMER stmg %r0,%r7,__PT_R0(%r11) + # clear user controlled register to prevent speculative use + xgr %r0,%r0 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC mvc __PT_PSW(16,%r11),__LC_SVC_OLD_PSW mvc __PT_INT_CODE(4,%r11),__LC_SVC_ILC @@ -550,6 +558,15 @@ ENTRY(pgm_check_handler) 3: stg %r10,__THREAD_last_break(%r14) 4: la %r11,STACK_FRAME_OVERHEAD(%r15) stmg %r0,%r7,__PT_R0(%r11) + # clear user controlled registers to prevent speculative use + xgr %r0,%r0 + xgr %r1,%r1 + xgr %r2,%r2 + xgr %r3,%r3 + xgr %r4,%r4 + xgr %r5,%r5 + xgr %r6,%r6 + xgr %r7,%r7 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC stmg %r8,%r9,__PT_PSW(%r11) mvc __PT_INT_CODE(4,%r11),__LC_PGM_ILC @@ -615,6 +632,16 @@ ENTRY(io_int_handler) lmg %r8,%r9,__LC_IO_OLD_PSW SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER stmg %r0,%r7,__PT_R0(%r11) + # clear user controlled registers to prevent speculative use + xgr %r0,%r0 + xgr %r1,%r1 + xgr %r2,%r2 + xgr %r3,%r3 + xgr %r4,%r4 + xgr %r5,%r5 + xgr %r6,%r6 + xgr %r7,%r7 + xgr %r10,%r10 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC stmg %r8,%r9,__PT_PSW(%r11) mvc __PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID @@ -820,6 +847,16 @@ ENTRY(ext_int_handler) lmg %r8,%r9,__LC_EXT_OLD_PSW SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER stmg %r0,%r7,__PT_R0(%r11) + # clear user controlled registers to prevent speculative use + xgr %r0,%r0 + xgr %r1,%r1 + xgr %r2,%r2 + xgr %r3,%r3 + xgr %r4,%r4 + xgr %r5,%r5 + xgr %r6,%r6 + xgr %r7,%r7 + xgr %r10,%r10 mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC stmg %r8,%r9,__PT_PSW(%r11) lghi %r1,__LC_EXT_PARAMS2 @@ -982,6 +1019,16 @@ ENTRY(mcck_int_handler) .Lmcck_skip: lghi %r14,__LC_GPREGS_SAVE_AREA+64 stmg %r0,%r7,__PT_R0(%r11) + # clear user controlled registers to prevent speculative use + xgr %r0,%r0 + xgr %r1,%r1 + xgr %r2,%r2 + xgr %r3,%r3 + xgr %r4,%r4 + xgr %r5,%r5 + xgr %r6,%r6 + xgr %r7,%r7 + xgr %r10,%r10 mvc __PT_R8(64,%r11),0(%r14) stmg %r8,%r9,__PT_PSW(%r11) xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)