linux-kernel - Re: [PATCH v9 29/36] x86/fred: FRED entry/exit and dispatch code

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4ccbf0e9-716d-dfe0-537c-210e5455418c@zytor.com>
Date:   Mon, 31 Jul 2023 14:44:20 -0700
From:   "H. Peter Anvin" <hpa@...or.com>
To:     Xin Li <xin3.li@...el.com>, linux-doc@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-edac@...r.kernel.org,
        linux-hyperv@...r.kernel.org, kvm@...r.kernel.org,
        xen-devel@...ts.xenproject.org
Cc:     Jonathan Corbet <corbet@....net>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
        Andy Lutomirski <luto@...nel.org>,
        Oleg Nesterov <oleg@...hat.com>,
        Tony Luck <tony.luck@...el.com>,
        "K . Y . Srinivasan" <kys@...rosoft.com>,
        Haiyang Zhang <haiyangz@...rosoft.com>,
        Wei Liu <wei.liu@...nel.org>, Dexuan Cui <decui@...rosoft.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Juergen Gross <jgross@...e.com>,
        Stefano Stabellini <sstabellini@...nel.org>,
        Oleksandr Tyshchenko <oleksandr_tyshchenko@...m.com>,
        Josh Poimboeuf <jpoimboe@...nel.org>,
        "Paul E . McKenney" <paulmck@...nel.org>,
        Catalin Marinas <catalin.marinas@....com>,
        Randy Dunlap <rdunlap@...radead.org>,
        Steven Rostedt <rostedt@...dmis.org>,
        Kim Phillips <kim.phillips@....com>,
        Hyeonggon Yoo <42.hyeyoo@...il.com>,
        "Liam R . Howlett" <Liam.Howlett@...cle.com>,
        Sebastian Reichel <sebastian.reichel@...labora.com>,
        "Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>,
        Suren Baghdasaryan <surenb@...gle.com>,
        Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>,
        Jiaxi Chen <jiaxi.chen@...ux.intel.com>,
        Babu Moger <babu.moger@....com>,
        Jim Mattson <jmattson@...gle.com>,
        Sandipan Das <sandipan.das@....com>,
        Lai Jiangshan <jiangshanlai@...il.com>,
        Hans de Goede <hdegoede@...hat.com>,
        Reinette Chatre <reinette.chatre@...el.com>,
        Daniel Sneddon <daniel.sneddon@...ux.intel.com>,
        Breno Leitao <leitao@...ian.org>,
        Nikunj A Dadhania <nikunj@....com>,
        Brian Gerst <brgerst@...il.com>,
        Sami Tolvanen <samitolvanen@...gle.com>,
        Alexander Potapenko <glider@...gle.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Arnd Bergmann <arnd@...db.de>,
        "Eric W . Biederman" <ebiederm@...ssion.com>,
        Kees Cook <keescook@...omium.org>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Masahiro Yamada <masahiroy@...nel.org>,
        Ze Gao <zegao2021@...il.com>, Fei Li <fei1.li@...el.com>,
        Conghui <conghui.chen@...el.com>,
        Ashok Raj <ashok.raj@...el.com>,
        "Jason A . Donenfeld" <Jason@...c4.com>,
        Mark Rutland <mark.rutland@....com>,
        Jacob Pan <jacob.jun.pan@...ux.intel.com>,
        Jiapeng Chong <jiapeng.chong@...ux.alibaba.com>,
        Jane Malalane <jane.malalane@...rix.com>,
        David Woodhouse <dwmw@...zon.co.uk>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        Arnaldo Carvalho de Melo <acme@...hat.com>,
        Yantengsi <siyanteng@...ngson.cn>,
        Christophe Leroy <christophe.leroy@...roup.eu>,
        Sathvika Vasireddy <sv@...ux.ibm.com>
Subject: Re: [PATCH v9 29/36] x86/fred: FRED entry/exit and dispatch code

On 7/30/23 23:41, Xin Li wrote:
> +
> +static DEFINE_FRED_HANDLER(fred_sw_interrupt_user)
> +{
> +	/*
> +	 * In compat mode INT $0x80 (32bit system call) is
> +	 * performance-critical. Handle it first.
> +	 */
> +	if (IS_ENABLED(CONFIG_IA32_EMULATION) &&
> +	    likely(regs->vector == IA32_SYSCALL_VECTOR)) {
> +		regs->orig_ax = regs->ax;
> +		regs->ax = -ENOSYS;
> +		return do_int80_syscall_32(regs);
> +	}

We can presumably drop the early out here as well...

> +
> +	/*
> +	 * Some software exceptions can also be triggered as
> +	 * int instructions, for historical reasons.
> +	 */
> +	switch (regs->vector) {
> +	case X86_TRAP_BP:
> +	case X86_TRAP_OF:
> +		fred_emulate_trap(regs);
> +		break;
> +	default:
> +		regs->vector = X86_TRAP_GP;
> +		fred_emulate_fault(regs);
> +		break;
> +	}
> +}
> +