From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x2262h8pmkBSoceBy6DE36H1KrHaT1dUdRscVM4e2Gotll17S/d0sdkeTJbypFSHyeS10fqLm ARC-Seal: i=1; a=rsa-sha256; t=1516611026; cv=none; d=google.com; s=arc-20160816; b=g44Eq/hrnMDsOe/koP/xbznVTEVMj8CERCbLff90fAULeVkLhTToTE1YJ3NgNa1gAu KfGjLj/7VObEBovoaJRXZwwHVOcfdficlAMk27H/NWv1RrB2Tip9BmpA/5KfzQDrQs1V l1ukIlVk3Jj/FdCfjEV7fOI9lN9M9mWO1EaDMzp+dw3UY56l7fp/CK73s3ZkePG/w/x5 UUQ9p/4H+5L6ebDaHb/+dh4SZ52/jUCqnPGAU2hK3f7IjhqoJeWcpXOscH2sK5r4Xto6 xVRrYEOzxnl4/Jk4Ve5DkRyorj/SnRM9jzlsRDLr3GzDwz9mIxb1p62gQhsx7NViottW xczw== 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=VH2FYtogXTGH8rJ7ZQkElZfjyhxmpIr1ub7tt3rnBE4=; b=LHsHrjTfa/cDSYvB258qPGEGpZBFZbGFDoQOcDnQj+qTlvs0vUIReH872wVO3f9efg s+WE0VcafKpLx0ukLYUs9WMyLMXKOFnDruQ5HsX6thDgxT4/chTTn+8KVGhc+73P0Kw7 tStBSJTix369NIN6cdWb9zNcsj6pxA9zN7hzC/3OnhPSXyiPaxEcGHMacyWCLHP5CkeD 9FdNMw5DRdXD8rj1+hmqw9Al9Ma81ZAyVzXzowPmVLlw5Bt2pORRBMmODtzPrFRPa0EU CUeAp+eEkhiSwzLO6aqQG+g09YSxh/Tj22G+bHbtS8/MPxYNRIMcENyQQaGUqPrbt1ZJ ekLQ== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 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 90.92.71.90 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 4.14 10/89] powerpc/64: Convert fast_exception_return to use RFI_TO_USER/KERNEL Date: Mon, 22 Jan 2018 09:44:50 +0100 Message-Id: <20180122083955.717588998@linuxfoundation.org> X-Mailer: git-send-email 2.16.0 In-Reply-To: <20180122083954.683903493@linuxfoundation.org> References: <20180122083954.683903493@linuxfoundation.org> User-Agent: quilt/0.65 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?1590281923414043492?= X-GMAIL-MSGID: =?utf-8?q?1590281923414043492?= 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: Nicholas Piggin commit a08f828cf47e6c605af21d2cdec68f84e799c318 upstream. Similar to the syscall return path, in fast_exception_return we may be returning to user or kernel context. We already have a test for that, because we conditionally restore r13. So use that existing test and branch, and bifurcate the return based on that. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/entry_64.S | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -892,7 +892,7 @@ BEGIN_FTR_SECTION END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) ACCOUNT_CPU_USER_EXIT(r13, r2, r4) REST_GPR(13, r1) -1: + mtspr SPRN_SRR1,r3 ld r2,_CCR(r1) @@ -905,8 +905,22 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) ld r3,GPR3(r1) ld r4,GPR4(r1) ld r1,GPR1(r1) + RFI_TO_USER + b . /* prevent speculative execution */ - rfid +1: mtspr SPRN_SRR1,r3 + + ld r2,_CCR(r1) + mtcrf 0xFF,r2 + ld r2,_NIP(r1) + mtspr SPRN_SRR0,r2 + + ld r0,GPR0(r1) + ld r2,GPR2(r1) + ld r3,GPR3(r1) + ld r4,GPR4(r1) + ld r1,GPR1(r1) + RFI_TO_KERNEL b . /* prevent speculative execution */ #endif /* CONFIG_PPC_BOOK3E */