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
| ||
|
Date: Thu, 19 Oct 2006 01:33:40 -0400 From: Len Brown <len.brown@...el.com> To: Dave Jones <davej@...hat.com> Cc: Linux Kernel <linux-kernel@...r.kernel.org>, linux-acpi@...r.kernel.org Subject: Re: SMP broken on pre-ACPI machine. On Wednesday 18 October 2006 18:24, Dave Jones wrote: > I've been chasing a bug that got filed against the Fedora kernel > a while back: https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=199052 > This is a dual pentium pro from an era before we had ACPI, and > it seems to be falling foul of this test in smpboot.c .. > > if (!smp_found_config && !acpi_lapic) { > printk(KERN_NOTICE "SMP motherboard not detected.\n"); > smpboot_clear_io_apic_irqs(); > phys_cpu_present_map = physid_mask_of_physid(0); > if (APIC_init_uniprocessor()) > printk(KERN_NOTICE "Local APIC not detected." > " Using dummy APIC emulation.\n"); > map_cpu_to_logical_apicid(); > cpu_set(0, cpu_sibling_map[0]); > cpu_set(0, cpu_core_map[0]); > return; > } > > > My initial reaction is that the !acpi_lapic test should be conditional > on some variable that gets set if the ACPI parsing actually succeeded. acpi_lapic isn't related to the problem at hand -- that smp_found_config is not set. That said, allowing acpi_lapic=1 to bail out of this check has the sole function of allowing SMP/PIC configurations. (smp_found_config in ACPI mode is set if acpi_lapic and acpi_ioapic are set) SMP/PIC configurations are not very interesting, except for debugging. Indeed, MPS prohibits them by mandating an IOAPIC be present for SMP -- but ACPI has no such rule. -Len - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists