1 / 26

The AMD64/EM64T Port of Dyninst and Paradyn

The AMD64/EM64T Port of Dyninst and Paradyn. Greg Quinn gquinn@cs.wisc.edu Ray Chen rchen@cs.umd.edu. Goals. 64-bit Dyninst library and Paradyn daemon that handle both 32-bit and 64-bit mutatees Leverage as much existing functionality as possible. Talk Outline. 32-Bit Compatibility

rachelford
Download Presentation

The AMD64/EM64T Port of Dyninst and Paradyn

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The AMD64/EM64T Port of Dyninst and Paradyn Greg Quinn gquinn@cs.wisc.edu Ray Chen rchen@cs.umd.edu

  2. Goals • 64-bit Dyninst library and Paradyn daemon that handle both 32-bit and 64-bit mutatees • Leverage as much existing functionality as possible

  3. Talk Outline • 32-Bit Compatibility • 64-Bit Mode • Architectural Overview • Issues for Dyninst • Current status and timeline for the port

  4. 32-Bit Compatibility

  5. Problematic Porting • Conceptually simple • ISA extension • Hardware compatibility • Pre-existing code base • Nightly regression tests

  6. System Structures • What’s wrong with this code? struct link_map { /* Base address shared object is loaded at.*/ ElfW(Addr) l_addr; /* Absolute file name object was found in.*/ char *l_name; /* Dynamic section of the shared object.*/ ElfW(Dyn) *l_ld; /* Chain of loaded objects. */ struct link_map *l_next, *l_prev; };

  7. System Structures • Compile-time decisions unacceptable • Structure size depends on target platform • X86: sizeof( ElfW(Addr) ) == 4 • X86_64: sizeof( ElfW(Addr) ) == 8 • Similar problem with pointer data types #define ElfW(type) \ Elf ## __ELF_NATIVE_CLASS ## type

  8. System Structures • No backwards compatible structure • Must create and maintain our own • Multiple structures affected • link_map, r_debug, libelf routines struct link_map_dyn32 { Elf32_Addr l_addr; uint32_t l_name; uint32_t l_ld; uint32_t l_next, l_prev; };

  9. System Structures • Class based solution • Hierarchy with 32-bit and 64-bit siblings • Virtual functions instead of control structures • Multiple benefits • No code duplication • Less source clutter • Minor function call overhead

  10. What Works? • Operation on 32-bit binaries at 95% • Passes most nightly regression tests • Tests 1-12, attach, relocate • Save the World not fully tested • Existing x86 shared library issue

  11. 64-Bit Mode Architectural Overview

  12. 32-bit Mode: Eight 32-bit registers Registers EAX EBX ECX EDX EBP ESP EDI ESI

  13. 32-bit Mode: Eight 32-bit registers 64-bit Mode: Registers extended to 64 bits Registers RAX RBX RCX RDX RBP RSP RDI RSI

  14. 32-bit Mode: Eight 32-bit registers 64-bit Mode: Registers extended to 64 bits Eight additional registers Registers RAX RBX RCX RDX RBP RSP RDI RSI R8 R9 R10 R11 R12 R13 R14 R15

  15. Registers • Encoded using REX prefix: 0100 W R X B Determines Width of Operation (32/64) Serve as High Order Bits for Register Numbers

  16. Immediate Values • Variable-length instructions allow for register-sized immediates (8 bytes) • MOV RAX, 0x1234567890abcdef • This is the only way to specify an 8-byte value in an instruction • Most importantly for Dyninst: • there is no JMP w/ 8-byte displacement

  17. Handling 64-Bit Mutatees

  18. Instruction Parsing • x86 instruction parser collects basic block information and searches for instrumentation points • We can use the same parsing algorithm for 64-bit mutatees • Architectural changes are abstracted away by instruction decoding • Bonus: support for stripped binaries

  19. Executing Instrumentation Mutatee Address Space • Dyninst maintains a heap of non-contiguous memory areas in the mutatee • Instrumentation points jump to code in nearby heap region • Code for this already exists (AIX, Solaris) executable library code

  20. Executing Instrumentation Mutatee Address Space • Dyninst maintains a heap of non-contiguous memory areas in the mutatee • Instrumentation points jump to code in nearby heap region • Code for this already exists (AIX, Solaris) executable dyninst heap region library code

  21. Executing Instrumentation Mutatee Address Space • Dyninst maintains a heap of non-contiguous memory areas in the mutatee • Instrumentation points jump to code in nearby heap region • Code for this already exists (AIX, Solaris) executable dyninst heap region >> 4GB spacing library code

  22. Executing Instrumentation Mutatee Address Space • Dyninst maintains a heap of non-contiguous memory areas in the mutatee • Instrumentation points jump to code in nearby heap region • Code for this already exists (AIX, Solaris) executable dyninst heap region >> 4GB spacing library code dyninst heap region

  23. Code Generation • Improved architecture allows for more efficient code generation • Stack no longer used for passing arguments • More registers means stack no longer needed for temporary values

  24. Good Things™ • We have been able to leverage x86 port extensively (code reuse) • Some 32-bit headaches go away • Non-standard optimizations in mutatee code (_dl_open example) • More registers allow for more efficient instrumentation code

  25. Status/Timeline • Now working: • 32-bit support • Instruction decoding, parsing • Left to do: • Code generation • Memory allocation • Counter, timers, and sampling code for Paradyn • Beta release: 2Q05 • Available for partners and friends • Production release: 3Q05

  26. Questions?

More Related