linux-kernel - Re: [PATCH 1/3] xen/pv: allow pmu msr accesses to cause GP

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: <b9c7a953-dbfa-164f-7a18-1e230c70e124@oracle.com>
Date:   Mon, 26 Sep 2022 16:09:15 -0400
From:   Boris Ostrovsky <boris.ostrovsky@...cle.com>
To:     Juergen Gross <jgross@...e.com>, xen-devel@...ts.xenproject.org,
        x86@...nel.org, linux-kernel@...r.kernel.org
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        "H. Peter Anvin" <hpa@...or.com>
Subject: Re: [PATCH 1/3] xen/pv: allow pmu msr accesses to cause GP


On 9/26/22 10:18 AM, Juergen Gross wrote:
>   bool pmu_msr_read(unsigned int msr, uint64_t *val, int *err)
>   {
>   	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) {
> -		if (is_amd_pmu_msr(msr)) {
> -			if (!xen_amd_pmu_emulate(msr, val, 1))
> -				*val = native_read_msr_safe(msr, err);
> -			return true;
> +		if (!is_amd_pmu_msr(msr))


You should be able to move vendor check inside is_<vendor>_pmu_msr().


-boris


> +			return false;
> +		if (!xen_amd_pmu_emulate(msr, val, 1)) {
> +			*val = err ? native_read_msr_safe(msr, err)
> +				   : native_read_msr(msr);
>   		}
> +		return true;
>   	} else {