From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZocPafGgh30mbXWChr6X+ZpyROpL5kuoSUycqeOdOu2fwOWIXwpNkUoTS6p4e/Kbl4NZEKV ARC-Seal: i=1; a=rsa-sha256; t=1524837736; cv=none; d=google.com; s=arc-20160816; b=VhxRNBteEDNcsyH3ems5z49WujDmg8J0QipFKGtey2kQafZq3aVFpfKrr1tcrfXfHU U0o9pCi7ibeVT2mPu48KEL57DrywsYOnnKPhX0JYokbv6mWcaKsJqgROISqxE52tVaGI vQHIDruNksd2Av/JiKgZWhuUu+xdu0yE0og9PlSqwLmG7WMCnYkQMxt7Fxz7nku1B9LE V1CYPh+oA5T/abvmTH5MYdISaVJSJuqjxI0E7DJv8KZl/Gvoy1iJW01BTNLH21HkizEe SEkpL3dMP989Z29hSgDje8ZjyBpp16EiWpNVDBdW29HhBIh5GtjjsWezY7NpEPaGHD1R 6V1w== 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=sN8swHaD3eUQ+u36t5S/lhE1mzE90P3rUoQMeYGq3RM=; b=KmICM5ZqWtQOg4AywrlN1xKEfUeK7bZdpBg5eHYIAo5286af+BIlOK3vHeKLWVAmB4 TjMMQI5UoWKkJoz9SL8hYT1sv3+CT39frTWdD8fUcwMLE22cd+6ebmUlwdZl7PAEBy4c 5aKXvZUQg23yLBHmwV6tSIoyI2xBB2I9ViYjvRWHViEajb26TaNlAv5jFJ5QhTVHRFGl 6lX7cDg4d0faytr2b8+kjDHWRr8XdaBNZAQBRZC3BOS+hMDhhPVGI97wNBrD9rumyDaF AG5cZ6XlKZiO8hal5c6dTBNxpAaUIy9GP2FDFxnhrtajni9DQvZ4z/2n3PXtFYHECbEu OdtQ== 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 DC3782189F 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 4.4 13/50] s390: scrub registers on kernel entry and KVM exit Date: Fri, 27 Apr 2018 15:58:15 +0200 Message-Id: <20180427135656.501299808@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180427135655.623669681@linuxfoundation.org> References: <20180427135655.623669681@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?1598908254418187128?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.4-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 @@ -244,6 +244,12 @@ 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 @@ -277,6 +283,8 @@ ENTRY(system_call) .Lsysc_vtime: UPDATE_VTIME %r10,%r13,__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 @@ -504,6 +512,15 @@ ENTRY(pgm_check_handler) mvc __THREAD_trap_tdb(256,%r14),0(%r13) 3: 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 @@ -567,6 +584,16 @@ 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 @@ -742,6 +769,16 @@ 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 @@ -908,6 +945,16 @@ 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)