From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.3 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 36FCFC83002 for ; Tue, 28 Apr 2020 02:52:00 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9717D206D9 for ; Tue, 28 Apr 2020 02:51:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="K7D1r1ze" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9717D206D9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 49B5lK1bXLzDqth for ; Tue, 28 Apr 2020 12:51:57 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gmail.com (client-ip=2607:f8b0:4864:20::642; helo=mail-pl1-x642.google.com; envelope-from=jniethe5@gmail.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=K7D1r1ze; dkim-atps=neutral Received: from mail-pl1-x642.google.com (mail-pl1-x642.google.com [IPv6:2607:f8b0:4864:20::642]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 49B4dg2b5xzDqRr for ; Tue, 28 Apr 2020 12:01:59 +1000 (AEST) Received: by mail-pl1-x642.google.com with SMTP id k18so7721002pll.6 for ; Mon, 27 Apr 2020 19:01:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=IMm3yLaxfptXxCuG3g4CUmafNqnMtCP+8ADv+1wXe1M=; b=K7D1r1ze8DyElMsTol64gVlq349d7eHFwy5dTkBzhFieWMDw4Zu/1dsc3DnynWwRfJ BdOGTu6Xdx1t7VJFu90XPtWTWhYm5VS4ESavI8DBcN2p1QNfsTL2I2iEBjiuvYIVDvlN p9XoUn1fpe/s78L/EyjgJMGP7JizHBLQci+jFA5E7MKV3AjM/r2RbsBZ16JGc8jsUc4n SNatGP5zVf1zpSdkvrHydsy305u1nO0AV0imFr1ssUmWOfXXzfOAEN+6P+gc1HjmaD0J o8k7IPR7c2SoUNLcgUQvxdZyabbaNDHyYq1iRYHaz7ntGRqps250GbJTC6wLDXT8thT0 gNTA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=IMm3yLaxfptXxCuG3g4CUmafNqnMtCP+8ADv+1wXe1M=; b=WUZZPFL1AubhY5FqIqPGZtv95mbnmRa0T5um4MxXYgr4KKSW8ZKTLlbuHEd9qUOjAL A0G6xvNlcmxcFQFqV6nt+wTtVr0spO1uFNKs1rKfKZKlD09NHuRNuVV7YB1Q4Tkob5NL oAofjp1gsm0YpbZTaPQOKDQ4UQ10PcBYKiTSeH51dsHI0UQvpLkYfUktmNDO8O/4eiqD QhmuS2SS6vgQdMJEVluzsxOrECo9WOPETW2vEsFGmLMoIiWosrGa1f+E5pp7d59IFvuE OgsXmvMb+WVGKBDLwCwtekhBtzqPcbjUAiczEnxGyCeSBI1ClsbvICn/FC6BZaVOflxK /Erg== X-Gm-Message-State: AGi0PuaZOAmy52tmnXp6ufglJUumOvnuMX+2u8OzLnneBsW9BKTksC1I o/ma4Fp1G7zqRl924RT2Wv0/YNBeXLA= X-Google-Smtp-Source: APiQypJPY+DFiAaRCTDV63Qp5t7pdWqDk49fBjklDVvSA3kRG3g8srdt60ooyjJql7gPaLUbzS5Miw== X-Received: by 2002:a17:90a:28e5:: with SMTP id f92mr2036233pjd.38.1588039316930; Mon, 27 Apr 2020 19:01:56 -0700 (PDT) Received: from localhost.localdomain (180-150-65-4.b49641.syd.nbn.aussiebb.net. [180.150.65.4]) by smtp.gmail.com with ESMTPSA id o68sm13666642pfb.206.2020.04.27.19.01.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Apr 2020 19:01:56 -0700 (PDT) From: Jordan Niethe To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH v6 26/28] powerpc: Support prefixed instructions in alignment handler Date: Tue, 28 Apr 2020 11:58:12 +1000 Message-Id: <20200428015814.15380-27-jniethe5@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200428015814.15380-1-jniethe5@gmail.com> References: <20200428015814.15380-1-jniethe5@gmail.com> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: alistair@popple.id.au, npiggin@gmail.com, bala24@linux.ibm.com, Jordan Niethe , dja@axtens.net Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" If a prefixed instruction results in an alignment exception, the SRR1_PREFIXED bit is set. The handler attempts to emulate the responsible instruction and then increment the NIP past it. Use SRR1_PREFIXED to determine by how much the NIP should be incremented. Prefixed instructions are not permitted to cross 64-byte boundaries. If they do the alignment interrupt is invoked with SRR1 BOUNDARY bit set. If this occurs send a SIGBUS to the offending process if in user mode. If in kernel mode call bad_page_fault(). Signed-off-by: Jordan Niethe --- v2: - Move __get_user_instr() and __get_user_instr_inatomic() to this commit (previously in "powerpc sstep: Prepare to support prefixed instructions"). - Rename sufx to suffix - Use a macro for calculating instruction length v3: Move __get_user_{instr(), instr_inatomic()} up with the other get_user definitions and remove nested if. v4: Rolled into "Add prefixed instructions to instruction data type" v5: Only one definition of inst_length() --- arch/powerpc/kernel/traps.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index a4764b039749..9b97d2e6055a 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -583,6 +583,8 @@ static inline int check_io_access(struct pt_regs *regs) #define REASON_ILLEGAL (ESR_PIL | ESR_PUO) #define REASON_PRIVILEGED ESR_PPR #define REASON_TRAP ESR_PTR +#define REASON_PREFIXED 0 +#define REASON_BOUNDARY 0 /* single-step stuff */ #define single_stepping(regs) (current->thread.debug.dbcr0 & DBCR0_IC) @@ -597,12 +599,16 @@ static inline int check_io_access(struct pt_regs *regs) #define REASON_ILLEGAL SRR1_PROGILL #define REASON_PRIVILEGED SRR1_PROGPRIV #define REASON_TRAP SRR1_PROGTRAP +#define REASON_PREFIXED SRR1_PREFIXED +#define REASON_BOUNDARY SRR1_BOUNDARY #define single_stepping(regs) ((regs)->msr & MSR_SE) #define clear_single_step(regs) ((regs)->msr &= ~MSR_SE) #define clear_br_trace(regs) ((regs)->msr &= ~MSR_BE) #endif +#define inst_length(reason) (((reason) & REASON_PREFIXED) ? 8 : 4) + #if defined(CONFIG_E500) int machine_check_e500mc(struct pt_regs *regs) { @@ -1593,11 +1599,20 @@ void alignment_exception(struct pt_regs *regs) { enum ctx_state prev_state = exception_enter(); int sig, code, fixed = 0; + unsigned long reason; /* We restore the interrupt state now */ if (!arch_irq_disabled_regs(regs)) local_irq_enable(); + reason = get_reason(regs); + + if (reason & REASON_BOUNDARY) { + sig = SIGBUS; + code = BUS_ADRALN; + goto bad; + } + if (tm_abort_check(regs, TM_CAUSE_ALIGNMENT | TM_CAUSE_PERSISTENT)) goto bail; @@ -1606,7 +1621,8 @@ void alignment_exception(struct pt_regs *regs) fixed = fix_alignment(regs); if (fixed == 1) { - regs->nip += 4; /* skip over emulated instruction */ + /* skip over emulated instruction */ + regs->nip += inst_length(reason); emulate_single_step(regs); goto bail; } @@ -1619,6 +1635,7 @@ void alignment_exception(struct pt_regs *regs) sig = SIGBUS; code = BUS_ADRALN; } +bad: if (user_mode(regs)) _exception(sig, regs, code, regs->dar); else -- 2.17.1