linux-kernel - Re: [PATCH V4 1/4] arm_pmu: acpi: Refactor arm_spe_acpi_register

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: <9d22520a-3450-0e75-59a2-035209f239e6@arm.com>
Date:   Fri, 11 Aug 2023 14:13:42 +0530
From:   Anshuman Khandual <anshuman.khandual@....com>
To:     linux-arm-kernel@...ts.infradead.org, suzuki.poulose@....com
Cc:     yangyicong@...wei.com, Sami Mujawar <sami.mujawar@....com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Mike Leach <mike.leach@...aro.org>,
        Leo Yan <leo.yan@...aro.org>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        James Clark <james.clark@....com>, coresight@...ts.linaro.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH V4 1/4] arm_pmu: acpi: Refactor
 arm_spe_acpi_register_device()

On 8/8/23 13:52, Anshuman Khandual wrote:
> +	/*
> +	 * Sanity check all the GICC tables for the same interrupt
> +	 * number. For now, only support homogeneous ACPI machines.
> +	 */
> +	for_each_possible_cpu(cpu) {
> +		struct acpi_madt_generic_interrupt *gicc;
> +
> +		gicc = acpi_cpu_get_madt_gicc(cpu);
> +		if (gicc->header.length < len)
> +			return gsi ? -ENXIO : 0;
> +
> +		this_gsi = parse_gsi(gicc);
> +		if (!this_gsi)
> +			return gsi ? -ENXIO : 0;
> +
> +		this_hetid = find_acpi_cpu_topology_hetero_id(cpu);
> +		if (!gsi) {
> +			hetid = this_hetid;
> +			gsi = this_gsi;
> +		} else if (hetid != this_hetid || gsi != this_gsi) {
> +			pr_warn("ACPI: %s: must be homogeneous\n", pdev->name);
> +			return -ENXIO;
> +		}
> +	}

As discussed on the previous version i.e V3 thread, will move the
'this_gsi' check after parse_gsi(), inside if (!gsi) conditional
block. This will treat subsequent cpu parse_gsi()'s failure as a
mismatch thus triggering the pr_warn() message.

diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c
index 845683ca7c64..6eae772d6298 100644
--- a/drivers/perf/arm_pmu_acpi.c
+++ b/drivers/perf/arm_pmu_acpi.c
@@ -98,11 +98,11 @@ arm_acpi_register_pmu_device(struct platform_device *pdev, u8 len,
                        return gsi ? -ENXIO : 0;
 
                this_gsi = parse_gsi(gicc);
-               if (!this_gsi)
-                       return gsi ? -ENXIO : 0;
-
                this_hetid = find_acpi_cpu_topology_hetero_id(cpu);
                if (!gsi) {
+                       if (!this_gsi)
+                               return 0;
+
                        hetid = this_hetid;
                        gsi = this_gsi;
                } else if (hetid != this_hetid || gsi != this_gsi) {