This semester, since we have 220 minutes of lecture time per week, we will not have dicussion sections (even though the schedule classes says that discussion time is "TBA"). In previous semesters, we use discussion sections to give you information about up-coming programming assignments. For this semester, we still be giving you the same information in lecture videos, although we will call them "discussion section videos" to emphasize that the information given was identical to what's given in discussion sections in previous semesters.

Please note that programming assignments are due on Fridays. Since you are expected to have finished the an assignment before its due date, on the due date of a programming assignment, the TA will be focusing on the next programming assignment and that takes priority over the current assignment. If there is time left, the TA can discuss the current assignment.

To download all the PDF and text files below in one command, do the following inside a terminal in Ubuntu 16.04:

    wget -r -l 1 --user=USERID --password=PASSWORD http://merlot.usc.edu/cs402-f22/discussions.html

where USERID and PASSWORD are the user ID and password used to access protected content from our class web site. But please note that the slides can change at any time without notice. Therefore, it's a good idea to re-run the above command often to synchroniza your copy with the server!

The following are tentative discussion section slides (in PDF and TXT formats) for this semester.

Please note that the source code below is for the purpose of discussions and may not be identical to the code in your assignments. It would be a really bad idea (because you can lose a lot of points) to replace the code in your assignments with the code here! So, please do not replace the code in your assignments with the code here.

• Week 1 (PDF) - gdb, warmup #1
• Week 2 (PDF) - parsing text input in C, Unix/Linux commands
• Week 3 (PDF) - introduction to warmup #2
• Week 4 (PDF) - warmup #2 (catching SIGINT and pthread cancellation), introduction to kernel assignments (part 1)

  Code in slides:

  • defs.h
  • fork-wait.c
  • cat.c
  • redirect.c
  • thr-term.c
  • busywait.c
  • join.c
  • deadlock.c
  • trylock.c
  • whoopee.c
  • status-update.c
  • sigblock.c
  • sigwait.c
  • direct.c
  • cancel.c
  • three-threads.c

• Week 5 (PDF) - introduction to kernel assignments (part 2)
• Week 6 (PDF) - kernel 1, kmain.c

  Code (kernel)

  • kmain.c

• Week 7 (PDF) - more on kernel 1, faber_test.c

  Code (kernel)

  • faber_test.c

• Week 8 (PDF) - introduction to kernel 2

  Code (kernel):

  • namev.c (path name resolution code)

• Week 9 (TXT) - kernel 2 polymorphism, vfs.c, vnode.c, file.c, vfs_syscall.c, vn_mmobj_ops.c, ramfs.c, vfstest.c, faber_fs_test

  Code (kernel):

  • vfs.c
  • vnode.c
  • file.c
  • vfs_syscall.c
  • vn_mmobj_ops.c
  • ramfs.c (also look for any "_ops_t" in "kernel/include/fs/*.h", "kernel/fs/*.c" and "kernel/fs/ramfs/*.c")
  • vfstest.c
  • faber_fs_test.c

• Week 10 (PDF) - introduction to kernel 3, the elf32 loader

  Code (kernel):

  • elf32.c - the elf32 loader
  • exec.c
  • access.c

• Week 11 (PDF) - more on kernel 3, address space implementation (vmarea, mmobj, pframe, page table)

  Code (kernel):

  • vn_mmobj_ops.c - code for the mmobj inside a vnode
  • syscall.c (in the kernel)

  
  Code (user):

  • syscall.c (in the libc user space library)

  
  Kernel 3 FAQ:

  • meaning of pagenum

• Week 12 (TXT) - objdump, page fault handling, hello

  Code (kernel):

  • pagefault.c
  • syscall.c (in the kernel)
  • vn_mmobj_ops.c - code for the mmobj inside a vnode

  
  Code (user):

  • hello.c
  • syscall.c (in the libc user space library)

  
  Kernel 3 FAQ:

  • handle the first page fault
  • meaning of pagenum
  • page faults

  
  Useful Linux commands:

      objdump --disassemble --section=".text" user/usr/bin/hello.exec
      objdump --disassemble --section=".text" -S user/usr/bin/hello.exec
      objdump --headers user/usr/bin/hello.exec
      xxd -g 1 user/usr/bin/hello.exec

  Useful GDB commands:

      add-symbol-file user/usr/bin/hello.exec 0x08048094
      b __libc_static_entry
      b main
      b *0x12345678
      layout asm
      layout next
      si
      info registers
      kernel info vmmap_mapping_info curproc->p_vmmap

• Week 13 (TXT) - fork(), user space shell

  Code (user):

  • fork-and-wait.c
  • /sbin/init.c

  
  Kernel 3 FAQ:

  • do_fork()
  • "/sbin/init" not working

  Remaining user space programs:

  Code (user):

  • memtest.c
  • eatmem.c
  • forkbomb.c

  
  Kernel 3 FAQ:

  • dynamic region and do_brk()
  • make forkbomb run forever

• Week 14 - (no discussion section this week)
• Week 15 - (no discussion section this week)