Re: [tip:x86/urgent] x86/apic: Fix signedness bug in APIC ID validity checks
On Wed, 11 Apr 2018, Dou Liyang wrote: > Hi Thomas, > > At 04/10/2018 10:51 PM, tip-bot for Li RongQing wrote: > [...] > > > x86/apic: Fix signedness bug in APIC ID validity checks > > > > The APIC ID as parsed from ACPI MADT is validity checked with the > > apic->apic_id_valid() callback, which depends on the selected APIC type. > > > > For non X2APIC types APIC IDs >= 0xFF are invalid, but values > 0x7FFF > > Today when I am reading "Intel® 64 Architecture x2APIC Specification", I > find that below in chapter 2.4.1: > > The APIC ID value of _H and the highest value corresponding to > the imple-mented bit-width of the local APIC ID register in the system > are reserved and cannot be assigned to any logical processor. > > Seems, _H is also invalid for X2APIC types, Shall we also do the > validity check for X2APIC ID? > > acpi_parse_x2apic() > ... > /* Ignore invalid ID */ > if (apic_id == 0x) > return 0; Yes. I noticed that as well and just did not come around to write the patch. Thanks, tglx
Re: [tip:x86/urgent] x86/apic: Fix signedness bug in APIC ID validity checks
On Wed, 11 Apr 2018, Dou Liyang wrote: > Hi Thomas, > > At 04/10/2018 10:51 PM, tip-bot for Li RongQing wrote: > [...] > > > x86/apic: Fix signedness bug in APIC ID validity checks > > > > The APIC ID as parsed from ACPI MADT is validity checked with the > > apic->apic_id_valid() callback, which depends on the selected APIC type. > > > > For non X2APIC types APIC IDs >= 0xFF are invalid, but values > 0x7FFF > > Today when I am reading "Intel® 64 Architecture x2APIC Specification", I > find that below in chapter 2.4.1: > > The APIC ID value of _H and the highest value corresponding to > the imple-mented bit-width of the local APIC ID register in the system > are reserved and cannot be assigned to any logical processor. > > Seems, _H is also invalid for X2APIC types, Shall we also do the > validity check for X2APIC ID? > > acpi_parse_x2apic() > ... > /* Ignore invalid ID */ > if (apic_id == 0x) > return 0; Yes. I noticed that as well and just did not come around to write the patch. Thanks, tglx
Re: [tip:x86/urgent] x86/apic: Fix signedness bug in APIC ID validity checks
Hi Thomas, At 04/10/2018 10:51 PM, tip-bot for Li RongQing wrote: [...] x86/apic: Fix signedness bug in APIC ID validity checks The APIC ID as parsed from ACPI MADT is validity checked with the apic->apic_id_valid() callback, which depends on the selected APIC type. For non X2APIC types APIC IDs >= 0xFF are invalid, but values > 0x7FFF Today when I am reading "Intel® 64 Architecture x2APIC Specification", I find that below in chapter 2.4.1: The APIC ID value of _H and the highest value corresponding to the imple-mented bit-width of the local APIC ID register in the system are reserved and cannot be assigned to any logical processor. Seems, _H is also invalid for X2APIC types, Shall we also do the validity check for X2APIC ID? acpi_parse_x2apic() ... /* Ignore invalid ID */ if (apic_id == 0x) return 0; ... Thanks, dou
Re: [tip:x86/urgent] x86/apic: Fix signedness bug in APIC ID validity checks
Hi Thomas, At 04/10/2018 10:51 PM, tip-bot for Li RongQing wrote: [...] x86/apic: Fix signedness bug in APIC ID validity checks The APIC ID as parsed from ACPI MADT is validity checked with the apic->apic_id_valid() callback, which depends on the selected APIC type. For non X2APIC types APIC IDs >= 0xFF are invalid, but values > 0x7FFF Today when I am reading "Intel® 64 Architecture x2APIC Specification", I find that below in chapter 2.4.1: The APIC ID value of _H and the highest value corresponding to the imple-mented bit-width of the local APIC ID register in the system are reserved and cannot be assigned to any logical processor. Seems, _H is also invalid for X2APIC types, Shall we also do the validity check for X2APIC ID? acpi_parse_x2apic() ... /* Ignore invalid ID */ if (apic_id == 0x) return 0; ... Thanks, dou
