From patchwork Tue Apr 22 08:22:04 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Xin Li \(Intel\)" X-Patchwork-Id: 883449 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2912626738D; Tue, 22 Apr 2025 08:23:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745310242; cv=none; b=FnqSINWqW0kCwbkgt/EEMkleDT+/OOEJVTnRtYj3TPAMovtxiN2BUmbINDrPaGzZP3tI5zSizrMYhFzqi13KKW/hC0a5iNy9HcAZ78TryrC5ajdL9Z8bIU2EsNW+4B08wI+RlYI3zpdVU9tkQXZ/mFh8GWAZqFBja/C6nxNj6Lk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745310242; c=relaxed/simple; bh=yBGZYj6e60Xkd31sxfmX0SXfJgjyWcQUtEfLxC+yd5s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=E7vZAOKpSiFbdQoagPIJfrgtaLH7IBNr3iU/t/KwZMSJ9zhuNoYy6oklTMAeg9sqSBdlmknnxRtnmOfje1f1pG46V7zd2n0C/vq2vS23bC42v4mq4DNHVkjRbcuZq5iqDf53A39wPGLTt73btvW48KWGSseL/poyC/Wg8gfPn1I= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=OxFRBToW; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="OxFRBToW" Received: from terminus.zytor.com (terminus.zytor.com [IPv6:2607:7c80:54:3:0:0:0:136]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 53M8MG9b1954391 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Tue, 22 Apr 2025 01:23:07 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 53M8MG9b1954391 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2025042001; t=1745310189; bh=1txH+adcfOwIr5LH/ZlSlDHGsa/VNPa8LSISbt9l4Ro=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OxFRBToWvEqJ0D8+VHe17wCVzLMgXTwVfmryl84uMGCcCa1OR1gcYgk3F9JimIkEm Id/7hCRonS1tRSe3XbDtDY2rOOSRAECeUFgk8SnqUTUQVMI7fMsmlmLdA+V1Isnccx NyOxGoeye8+rFjFY7d/LaanWDAMzgutZnK7I8bQcQOzDgKbXuT2nLEFt3l17FoQjbN 0MBd1FBVWKYzzM4HdY+mKWx4rA3pjbiDgR4YfpiXTsRCo/G4/quQSJEIDnLLYiZ/pn +gaaR0PJHyRUhR9gBfrfjXO0nxpya9KvdRYx5dSosavK3jrRh2vDAAe1RpFOl3uFKb EUpT5J98djaIA== From: "Xin Li (Intel)" To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-hyperv@vger.kernel.org, virtualization@lists.linux.dev, linux-pm@vger.kernel.org, linux-edac@vger.kernel.org, xen-devel@lists.xenproject.org, linux-acpi@vger.kernel.org, linux-hwmon@vger.kernel.org, netdev@vger.kernel.org, platform-driver-x86@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, acme@kernel.org, jgross@suse.com, andrew.cooper3@citrix.com, peterz@infradead.org, namhyung@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, irogers@google.com, adrian.hunter@intel.com, kan.liang@linux.intel.com, wei.liu@kernel.org, ajay.kaher@broadcom.com, bcm-kernel-feedback-list@broadcom.com, tony.luck@intel.com, pbonzini@redhat.com, vkuznets@redhat.com, seanjc@google.com, luto@kernel.org, boris.ostrovsky@oracle.com, kys@microsoft.com, haiyangz@microsoft.com, decui@microsoft.com Subject: [RFC PATCH v2 23/34] x86/extable: Remove new dead code in ex_handler_msr() Date: Tue, 22 Apr 2025 01:22:04 -0700 Message-ID: <20250422082216.1954310-24-xin@zytor.com> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250422082216.1954310-1-xin@zytor.com> References: <20250422082216.1954310-1-xin@zytor.com> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The MSR read APIs no longer expect RAX or EDX:EAX to be cleared upon returning from #GP caused by MSR read instructions. The MSR safe APIs no longer assume -EIO being returned in a register from #GP caused by MSR instructions. Remove new dead code due to above changes. Signed-off-by: Xin Li (Intel) --- arch/x86/mm/extable.c | 21 +++++---------------- 1 file changed, 5 insertions(+), 16 deletions(-) diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c index 6bf4c2a43c2c..ea3fe7f32772 100644 --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -165,7 +165,7 @@ static bool ex_handler_uaccess(const struct exception_table_entry *fixup, } static bool ex_handler_msr(const struct exception_table_entry *fixup, - struct pt_regs *regs, bool wrmsr, bool safe, int reg) + struct pt_regs *regs, bool wrmsr, bool safe) { bool imm_insn = is_msr_imm_insn((void *)regs->ip); u32 msr; @@ -207,17 +207,6 @@ static bool ex_handler_msr(const struct exception_table_entry *fixup, show_stack_regs(regs); } - if (!wrmsr) { - /* Pretend that the read succeeded and returned 0. */ - regs->ax = 0; - - if (!imm_insn) - regs->dx = 0; - } - - if (safe) - *pt_regs_nr(regs, reg) = -EIO; - return ex_handler_default(fixup, regs); } @@ -395,13 +384,13 @@ int fixup_exception(struct pt_regs *regs, int trapnr, unsigned long error_code, case EX_TYPE_BPF: return ex_handler_bpf(e, regs); case EX_TYPE_WRMSR: - return ex_handler_msr(e, regs, true, false, reg); + return ex_handler_msr(e, regs, true, false); case EX_TYPE_RDMSR: - return ex_handler_msr(e, regs, false, false, reg); + return ex_handler_msr(e, regs, false, false); case EX_TYPE_WRMSR_SAFE: - return ex_handler_msr(e, regs, true, true, reg); + return ex_handler_msr(e, regs, true, true); case EX_TYPE_RDMSR_SAFE: - return ex_handler_msr(e, regs, false, true, reg); + return ex_handler_msr(e, regs, false, true); case EX_TYPE_WRMSR_IN_MCE: ex_handler_msr_mce(regs, true); break;