Each live discussion section is conducted by a TA. Below is a list showing which TA is responsible for which discussion section:

• Fri 10:00am - 10:50am OHE 136 (access through D2L) - Zhuojin Li
• Fri 12:00pm - 12:50pm SLH 100 (Zoom meeting ID is (TBD)) - Rohan Madhani

During a live discussion section, the TA will answer questions about the pre-recorded video and answer your questions about programming assignments. If you have a particular topic that you would like the TA to discuss in class (including stuff like something covered in lectures that you would like the TA to explain further), you should send e-mail to the TA before 6PM on Thursday. The TA will try his/her best to cover such requests.

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-s22/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!

(Please note that access to discussion slides and videos are restricted.)

Week 1 live discussion sections (PDF) - gdb, warmup #1 10am live discussion section - 30 minutes

Week 2 live discussion sections (PDF) - warmup #1 (part 2) 10am live discussion section - 15 minutes 12pm live discussion section - 25 minutes

Week 3 live discussion sections (PDF) - warmup #2 10am live discussion section - 19 minutes 12pm live discussion section - 14 minutes

Week 4 live discussion sections (PDF) - warmup #2 (catching SIGINT and pthread cancellation), introduction to kernel assignments (part 1) 10am live discussion section - 29 minutes 12pm live discussion section - 14 minutes

Week 5 live discussion sections (PDF) - introduction to kernel assignments (part 2) 10am live discussion section - 21 minutes 12pm live discussion section - 16 minutes

Week 6 live discussion sections (PDF) - kernel 1, kmain.c 10am live discussion section - 21 minutes 12pm live discussion section - 16 minutes

Week 7 live discussion sections (PDF) - more on kernel 1, faber_test.c 10am live discussion section - 9 minutes 12pm live discussion section - 13 minutes

Week 8 live discussion sections (PDF) - introduction to kernel 2 10am live discussion section - 19 minutes 12pm live discussion section - 15 minutes

Week 9 live discussion sections (TXT) - kernel 2 polymorphism, vfs.c, vnode.c, file.c, vfs_syscall.c, vn_mmobj_ops.c, ramfs.c, vfstest.c, faber_fs_test 10am live discussion section - 18 minutes 12pm live discussion section - 19 minutes

Week 10 live discussion sections (PDF) - introduction to kernel 3, the elf32 loader 10am live discussion section - 18 minutes 12pm live discussion section - 11 minutes

Week 11 live discussion sections (PDF) - more on kernel 3, address space implementation (vmarea, mmobj, pframe, page table) 10am live discussion section - 16 minutes 12pm live discussion section - 16 minutes

Week 12 live discussion sections (TXT) - objdump, page fault handling, hello 10am live discussion section - 20 minutes 12pm live discussion section - 8 minutes

Week 13 live discussion sections (TXT) - fork(), user space shell 10am live discussion section - 15 minutes 12pm live discussion section - 16 minutes

Please note that there will be no primary live discussion for Week 14 and Week 15 (we will only have the secondary live discussion on Zoom where you can ask the TA questions in breakout rooms).

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)