Descriptor, Segment descriptor, Block descriptor | IBM 10 SP1 EAL4

•DR: Data Address Translation. The value of 0 disables translation, and the value of 1 enables translation.

5.5.2.3.2Page descriptor

Pages are described by Page Table Entries (PTEs). The operating system generates and places PTEs in a page table in memory. A PTE on SLES is 128 bits in length. Bits relevant to access control are Page protection bits (PP), which are used with MSR and segment descriptor fields to implement access control.

Figure 5-43: Page table entry

5.5.2.3.3Segment descriptor

Figure 5-44: Segment Table Entry

Segments are described by Segment Table Entries (STEs). The operating system generates and places STEs in segment tables in memory. Each STE is a 128-bit entry that contains information for controlling segment search process, and for implementing the memory-protection mechanism.

Ks: Supervisor-state protection key

•Kp: User-state protection key

•N: No-execute protection bit

5.5.2.3.4Block descriptor

For address translation, a pair of special-purpose registers called upper and lower BAT (Block Address Translation) registers, which contain effective and physical addresses for the block, define each block.

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IBM 10 SP1 EAL4 manual Descriptor, Segment descriptor, Block descriptor

Contents

Page EJR Table of Contents 2.1 DAC AppArmor Programs with software privilege Permission bits Access Control Lists 100 142 175 207 250 252 269 Document overview Purpose of this documentConventions used in this document Terminology System Overview Suse Linux Enterprise Server Product historyEServer systems High-level product overview Overall structure of the TOE EServer host computer structurePage EServer system structure TOE services Security policy Local and network services provided by Sles TSF interfaces Operation and administration Approach to TSF identification Page Page System x hardware overview System x hardware architecture System System p hardware architecture System pSystem p hardware overview System z hardware overview System z hardware architecture System z EServer 326 hardware architecture EServerEServer 326 hardware overview AMD x86-64 architecture in compatibility mode Page Privilege level Hardware and software privilegeHardware privilege Levels of Privilege Software privilege AppArmor 2.1 DAC Programs with software privilege TOE Security Functions software structure Kernel TSF software Logical kernel subsystems and their interactions Logical components Kernel threads Execution componentsBase kernel Kernel modules and device drivers Non-kernel TSF softwarePage Definition of subsystems for the CC evaluation TSF databases Firmware HardwareKernel subsystems Trusted process subsystems User-level audit subsystem Page File and I/O management Functional descriptions Ext3 and CD-ROM file systems before mounting Virtual File System Ext3 and CD-ROM file systems after mounting Pathname translation VFS pathname translation and access control checks Open Shared subtrees WriteMount Extended Attributes Disk-based file systems2.1 Ext3 file system Data structures Page Page Data structures and algorithms ISO 9660 file system for CD-ROM Tmpfs Pseudo file systemsProcfs Rootfs SysfsDevpts Configfs Discretionary Access Control DACInotify Binfmtmisc Indicates read Permission bits ACL qualifier Access Control ListsTypes of ACL tags ACL permissions Default ACLs and ACL inheritanceRelationship to file permission bits Aclmask ACL enforcement 7 I/O scheduler Asynchronous I/O Completely Fair Queuing scheduler Deadline I/O schedulerAnticipatory I/O scheduler Noop I/O scheduler 8 I/O interruptsTop halves Bottom halves Machine check Processor interruptsTasklets Work queue Data structures Process control and managementPage DAC controls Process creation and destructionControl of child processes Kernel threads Process switchSetresuidand setresgid Execve Hyperthreading scheduler Scheduling 14 Hyperthreaded scheduling Kernel preemption Inter-process communication Data structures and algorithms Pipes Fifo creation First-In First-Out Named pipes Common data structures System V IPCFifo open Message queues Common functions Semaphores Shared memory regions Sockets SignalsData structures Algorithms 16 Object reuse handling in socket allocation Network subsystem Overview of the network protocol stack 18 How data travels through the Network protocol stack Network layer protocols Transport layer protocols 3.2.2 IPv6 Header Addressing Security Flow LabelsTransition between IPv4 and IPv6 IP Security IPsec AH Header Functional Description of IPsec An IP Packet with tunnel mode AH An IP Packet with tunnel mode ESP Link layer protocols Internet Control Message Protocol Icmp Address Resolution Protocol ARP Network services interface Bind Socket Connect ListenAccept Generic calls Access controlMemory management Page 24 Previous three-level page-tables architecture Four-Level Page Tables System Memory addressing 26 System x virtual addressing space Segmentation 28 Access control through segmentation Paging 30 Regular paging 32 Access control through paging For more information about call gates, refer to System p 33 Paging data structures 34 Logical partitions Privilege State 36 Determination of processor mode in Lpar Hypervisor Real mode addressingAddress Translation on LPARs Direct Memory Access addressing Virtual mode addressingAccess to I/O address space System p native mode Run-Time Abstraction ServicesPreventing denial of service 39 Effective address Machine State Register 41 Block address Block descriptor DescriptorSegment descriptor Address translation mechanisms 45 Block Address Translation entry Address Translation and access control 47 Block Address Translation access controlPage 48 Page Address Translation and access control Lpar mode Native hardware mode2.4.3 z/VM Guest mode System z Address translations Address sizesAddress spaces 49 System z address types and their translation 51 Address translation modes 52 64-bit or 31-bit Dynamic Address Translation 53 Low-address protection on effective address Memory protection mechanisms Table protection 113 114 56 Key match logic for key-controlled protection Logical address EServer Physical address Effective addressLinear address 59 Data access privilege checks Access control through type check Page 121 63 Page map level four entry Translation Lookaside Buffers Kernel memory management Reverse map Virtual Memory Support for Numa servers Huge Translation Lookaside Buffers 65 Rmap VM 66 TLB Operation Frame management Remapfilepages Noncontiguous memory area management Process address spaceMemory area management 68 Object reuse handling while allocating new linear address Memory barriers Symmetric multiprocessing and synchronizationAtomic operations Audit components Audit subsystemSpin locks Kernel semaphores Kernel-userspace interface Audit kernel components Task structure Syscall auditingFilesystem watches Audit context fields 71 Task Structure File system audit components User space audit components Configuration Audit operation and configuration options Option Description Possible values Operation Kernel record generation Audit recordsAudit record generation Syscall audit record generation 73 Audit Record Generation File system audit record generation 74 Extension to system calls interface Audit record format Socket call and IPC audit record generationRecord generation by trusted programs Page Event Description LAF audit events Audit tools Login uid associationKernel modules Auditctl Linux Security Module framework Structure AppArmor LSM capabilities moduleLSM AppArmor module Var/log/boot.msg Rwl Var/run/klogd.pid AppArmor administrative utilities Securityfs AppArmor access control functions Interpretive-execution facility Device drivers1 I/O virtualization on System z State description Hardware virtualization and simulation Character device driver Block device driver Init System initialization System Boot process Boot methodsBoot loader Linuxrc 79 System x Sles boot sequence System p Page System p in Lpar 80 System p Sles boot sequence Etc/sysconfig/init script 81 System p Lpar Sles boot sequence Control program System z 82describes the boot process for Sles as a z/VM guest EServer 82 System z Sles boot sequence 169 83schematically describes the boot process of eServer 170 83 eServer 326 Sles boot sequence Identification and authentication Overview Pluggable Authentication Module Modules Configuration terminology Etc/security/pamenv.conf Protected databases Access control rules Trusted commands and trusted processes11.2.1.1 DAC Agetty Gpasswd Login Newgrp Mingetty 11.3.7 su Passwd OpenSSL Secure socket-layer interface Interaction with auditNetwork applications 84 SSL location in the network stack Encryption Concepts 87 Encryption Algorithm and Key 88 Asymmetric keys Message digest Message Authentication Code MACDigital certificates and certificate authority SSL architecture SSL handshake protocol 90 SSL Protocol 187 Symmetric ciphers OpenSSL algorithms Hash functions Asymmetric ciphersCertificates Secure Shell SSH server daemon SSH client Cups Very Secure File Transfer Protocol daemon Cupsd Openssl PingPing6 Stunnel Account Management System managementXinetd Chage Chsh Chfn Usermod User managementUseradd Userdel Groupadd Group management Groupdel Groupmod 202 Other System Management System Time managementDate Hwclock Memory Supervisor mode instructionsMemory separation 13.5.1.3 I/O controller and network System p Star Amtu output 207 Batch processing Batch processing user commands13.6 I&A support 14.1.2 at 14.2.2 atd Batch processing daemonsCron Audit daemon User-level audit subsystemAudit utilities Aureport Autrace Audit configuration filesAudit logs TSF libraries Supporting functions LibraryDescription System call linking mechanism Library linking mechanism System call argument verification Pageoffset Audit Security management Discretionary Access ControlObject reuse TSF protection Secure communications Trusted processes TP.4 Testing the TOE protection mechanisms TP.7TSF Databases TP.5 Internal TOE protection mechanisms TP.6 External Interfaces Summary of kernel subsystem interfacesKernel subsystem file and I/O Internal function Interfaces defined Internal Interfaces 1.1.3 External interfaces system calls Kernel subsystem process control and management Kernel subsystem inter-process communication Internal Interfaces Dopipe Kernel subsystem memory management Kernel subsystem networking Internal interfaces Kernel subsystem audit Kernel subsystem device drivers Other functions Kernel subsystems kernel modules Summary of trusted processes interfaces References RSA 234