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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> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZohoMail-DKIM: pass (identity @zytor.com) X-ZM-MESSAGEID: 1745310236031019000 Content-Type: text/plain; charset="utf-8" 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_t= able_entry *fixup, } =20 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 =3D is_msr_imm_insn((void *)regs->ip); u32 msr; @@ -207,17 +207,6 @@ static bool ex_handler_msr(const struct exception_tabl= e_entry *fixup, show_stack_regs(regs); } =20 - if (!wrmsr) { - /* Pretend that the read succeeded and returned 0. */ - regs->ax =3D 0; - - if (!imm_insn) - regs->dx =3D 0; - } - - if (safe) - *pt_regs_nr(regs, reg) =3D -EIO; - return ex_handler_default(fixup, regs); } =20 @@ -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; --=20 2.49.0