From 168340ced86fcd020e6e44e0cf231cb31019bdf2 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Tue, 18 Jul 2023 12:39:29 +0200 Subject: [PATCH] x86/ACPI: correct off-by-1 in SGI MMCFG check MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit As supported by the printk() (deliberately made visible in context by also correcting a mis-indented return statement), "above 4GiB" is meant here. Avoid comparison with a constant to "escape" Misra rule 7.2 complaints. (Note however that even up-to-date Linux, which is where we "inherited" this code from, still uses the very same off-by-1 check.) Fixes: 94ea0622c5b8 ("x86-64/mmcfg: relax base address restriction") Signed-off-by: Jan Beulich Acked-by: Roger Pau Monné --- xen/arch/x86/x86_64/acpi_mmcfg.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/xen/arch/x86/x86_64/acpi_mmcfg.c b/xen/arch/x86/x86_64/acpi_mmcfg.c index 2159c68189..7b09046229 100644 --- a/xen/arch/x86/x86_64/acpi_mmcfg.c +++ b/xen/arch/x86/x86_64/acpi_mmcfg.c @@ -50,7 +50,7 @@ static int __init acpi_mcfg_check_entry(struct acpi_table_mcfg *mcfg, { int year; - if (cfg->address < 0xFFFFFFFF) + if (cfg->address == (uint32_t)cfg->address) return 0; if (!strncmp(mcfg->header.oem_id, "SGI", 3)) @@ -59,7 +59,7 @@ static int __init acpi_mcfg_check_entry(struct acpi_table_mcfg *mcfg, if (mcfg->header.revision >= 1 && dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) && year >= 2010) - return 0; + return 0; printk(KERN_ERR "MCFG region for %04x:%02x-%02x at %#"PRIx64 " (above 4GB) ignored\n",