Updated Linux Kernel 2.4 status/todo list

Date: Fri, 28 Jul 2000 11:31:15 -0400
From: tytso@mit.edu
To: linux-kernel@vger.rutgers.edu
Subject: Updated 2.4 status/todo list

Thanks to Al Viro, Jeff Garzik, Arjan van de Ven, Davem, Thomas Hiller,
Alan Cox, and any other whom I might have missed towards getting this
list more up-to-date.

I've also arranged to post the latest version of this list at:

        http://linux24.sourceforge.net

At the moment I'm only using the sourceforge project web page; this is
because my home DSL line is only 416k, and I didn't want it to get
Slashdotted.

As a preemptive strike, everyone and his brother has approached me
suggesting that I use their favorite bug tracking system.  The answer
which I'm giving folks is that for now, trying to get the information
into a sane state is far more important than the mechanism of which bug
tracking system to use.  At the moment, the hardest parts of the problem
are:

        * Figuring out when Linus has applied a patch that fixes a
                particular item on the bug list.

        * Determining when someone complains whether it's a real bug or
                not, and if so, how important is it.

        * Ditto for when someone posts a patch.

        * Figuring out what Alan meant by descriptive items such
                as "Check all devices use resources properly"
                (If anyone has a copy of Vulcan Mind Melds for Dummies,
                let me know.  :-)

Anyway, here's the latest list.   Enjoy.....

                                                        - Ted

                         Linux 2.4 Status/TODO Page

   Important note! I just recently inherited this list from Alan, so it
   may not be fully accurate yet. Please send updates to tytso@mit.edu.

   Last modified: [tytso:20000728.1115EDT]

Should Be Fixed (Confirmation Wanted)

     * IDE fails on some VIA boards (eg the i-opener)
     * Floppy driver broken by VFS changes. Other drivers may be too
       (Stuff gets called after _close now - unload race possibly too)
     * Fbcon races
     * Fix all remaining PCI code to use pci_enable_device (mostly done)

Capable Of Corrupting Your FS

     * Use PCI DMA by default in IDE is unsafe (must not do so on via VPx
       x<3)
     * Data corruption on IDE disks (Generic PCI DMA and SiS support
       (Steven Walter)

Security

     * Fix module remove race bug (still to be done: TTY, ldisc, I2C,
       video_device, network devices(?) - Al Viro)
     * access_process_mm oops/lockup if task->mm changes (Manfred) [user
       can cause deliberately]

Boot Time Failures

     * AHA29xx driver appears to stomp other cards (may be BIOS)
     * AHA27xx is broken (maybe 28xx too)
     * Use PCI DMA 'lost interrupt' problem with some hw [which ?] (NEC
       Versa LX with PIIX tuning)
     * HT6560/UMC8672 ide sets up stuff too early (before region stuff
       can be done)
     * Crashes on boot on some Compaqs ? (may be fixed)
     * Boot hangs on a range of Dell docking stations (Latitude)

Compile-time failures

     * pdc202xx.c doesn't compile under test5

In Progress

     * Merge the network fixes (DaveM)
     * Finish I2O merge (Intel/Alan)
     * Exploitable leak in file locking (Willy)
     * Restore O_SYNC functionality (Stephen) - core code and ext2 done

Obvious Projects For People (well if you have the hardware..)

     * nNCR5380 isnt smp safe
     * DMFE is not SMP safe
     * Make syncppp use new ppp code
     * Fix SPX socket code
     * Merge the 2.2 ServeRAID driver into 2.4

Fix Exists But Isnt Merged

     * Update SGI VisWS to new-style IRQ handling (Ingo)
     * 64bit lockf support
     * Support MP table above 1Gig (Ingo)
     * Dont panic on boot when meeting HP boxes with wacked APIC table
       numbering (AC)
     * Scheduler bugs in RT (Dimitris)
     * HFS is still broken
     * AIC7xxx doesnt work non PCI ? (Doug says OK, new version due
       anyway)
     * Fix boards with different TSC per CPU and kill TSC use on them
     * Floppy last block cache flush error
     * TB Multisound driver hasnt been updated for new isa I/O totally.

Compatibility Errors

     * Xterm broke in 2.3.99pre6 (FIONREAD/select loop)

To Do

     * mount crashes on Alpha platforms
     * Check all devices use resources properly
     * Tulip hang on rmmod/crashes sometimes
     * Devfs races (mostly done - Al Viro)
     * Fix further NFS races (Al Viro)
     * Test other file systems on write
     * Audit all char and block drivers to ensure they are safe with the
       2.3 locking - a lot of them are not especially on the
       read()/write() path.
     * Keyboard/mouse problems (may be fixed ?)
     * Fix mount failures due to copy_* user mishandling
     * Fix default mount behaviour to disallow repeat mounting
     * Check all file systems are either LFS compliant or error large
       files
     * Issue with notifiers that try to deregister themselves? (lnz)
     * Mount of new fs over existing mointpoint should return an error
       unless forced (Andrew McNabb, Alan Cox)
     * Kernel build has race conditions when building modversions.h
       (Mikael Pettersson)

To Do But Non Showstopper

     * Finish 64bit vfs merges (lockf64 and friends missing)
     * Go through as 2.4pre kicks in and figure what we should mark
       obsolete for the final 2.4
     * Union mount (Al Viro)
     * Per Process rtsigio limit
     * iget abuse in knfsd
     * Some people report 2.3.x serial problems
     * USB hangs on APM suspend on some machines
     * ISAPnP IRQ handling failing on SB1000 + resource handling bug
     * DVD-RAM is apparently not working for write currently (Rogier
       Wolff)
     * Parallel ports should set SA_SHIRQ if PCI (eg in Plip)
     * Devfs compiled in but not mounted causes crap for ->mnt_devname of
       root (Al Viro)
     * PCMCIA/Cardbus hangs, IRQ problems. (Basically unusable - Hinds
       pcmcia code is reliable)
          + PCMCIA crashes on unloading pci_socket
          + yenta (PCMCIA) and pci_socket modules have mutual dependency
            (cardbus_register, yenta_operations) (test5, worked in test3)

To Check

     * Check O_APPEND atomicity bug fixing is complete
     * Protection on i_size (sct) [Al Viro mostly done]
     * Mikulas claims we need to fix the getblk/mark_buffer_uptodate
       thing for 2.3.x as well
     * Network block device seems broken by block device changes
     * VFS?VM - mmap/write deadlock (demo code seems to show lock is
       there)
     * rw sempahores on page faults (mmap_sem)
     * kiobuf seperate lock functions/bounce/page_address fixes
     * Fix routing by fwmark
     * rw semaphores on inodes to fix read/truncate races ? [Probably
       fixed]
     * Not all device drivers are safe now the write inode lock isnt
       taken on write
     * Multiwrite IDE breaks on a disk error [minor issue at best]
     * ACPI/APM suspend issue - IDE related stuff ?
     * NFS bugs are fixed
     * Chase reports of SMB not working
     * IRDA calls get random bytes before random is set up
     * Some AWE cards are not being found by ISAPnP ??
     * SHM segments not always being detached and destroyed right ?
     * RAM disk contents vanishing on cramfs (block change) and bforget
       cases
     * ACPI hangs on boot for some systems (Are there any cases left ?)

Drivers In 2.2 not 2.4

Probably Post 2.4

     * per super block write_super needs an async flag
     * addres_space needs a VM pressure/flush callback (Ingo)
     * per file_op rw_kiovec

Fixed

     * Incredibly slow loopback tcp bug (believed fixed about 2.3.48)
     * COMX series WAN now merged
     * VM needs rebalancing or we have a bad leak
     * SHM works chroot
     * SHM back compatibility
     * Intel i960 problems with I2O
     * Symbol clashes and other mess from _three_ copies of zlib!
     * PCI buffer overruns
     * Shared memory changes change the API breaking applications (eg
       gimp)
     * Finish softnet driver port over and cleanups
     * via rhine oopses under load ?
     * SCSI generic driver crashes controllers (need to pass
       PCI_DIR_UNKNOWN..)
     * UMSDOS fixups resync (not quite done)
     * Make NTFS sort of work
     * Any user can crash FAT fs code with ftruncate
     * AFFS fixups
     * Directory race fix for UFS
     * Security holes in execve()
     * Lan Media WAN update for 2.3
     * Get the Emu10K merged
     * Paride seems to need fixes for the block changes yet
     * Kernel corrupts fs and gs in some situations (Ulrich has demo
       code)
     * 1.07 AMI MegaRAID
     * Merge 2.2.15 changes (Alan)
     * Get RAID 0.90 in (Ingo)
     * S/390 Merge
     * NFS DoS fix (security)
     * Merge the RIO driver
     * Fix Space.c duplicate string/write to constants
     * Elevator and block handling queue change errors are all sorted
     * Make sure all drivers return 1 from their __setup functions (Done
       ?)
     * Enhanced disk statistics
     * Complete vfsmount merge (Al Viro)
     * Merge removed-buf-open directory stuff into VFS (Al Viro)
     * Problems with ip autoconfig according to Zaitcev
     * NFS causes dup kmem_create on reload (Trond)
     * vmalloc(GFP_DMA) is needed for DMA drivers (Ingo)
     * TLB flush should use highest priority (Ingo)
     * SMP affinity code creates multiple dirs with the same name (Ingo)
     * Set SMP affinity mask to actual cpu online mask (needed for some
       boards) (Ingo)
     * heavy swapping corrupts ptes (believed so)
     * pci_set_master forces a 64 latency on low latency setting
       devices.Some boards require all cards have latency <= 32
     * msync fails on NFS (probably fixed anyway)
     * Find out what has ruined disk I/O throughput. (mostly)
     * PIII FXSAVE/FXRESTORE support
     * The netdev name changing stuff broke GRE
     * put_user is broken for i386 machines (security) - sem stuff may be
       wrong too
     * BusLogic crashes when you cat /proc/scsi/BusLogic/0 (Robert de
       Vries)
     * Finish sorting out VM balancing (Rik Van Riel, Juan Quintela et
       al)
     * Fix eth= command line
     * 8139 + bridging fails
     * RtSig limit handling bug
     * Signals leak kernel memory (security) [FIX in ac tree]
     * TTY and N_HDLC layer called poll_wait twice per fd and corrupt
       memory
     * ATM layer calls poll_wait twice per fd and corrupts memory
     * Random calls poll_wait twice per fd and corrupts memory
     * PCI sound calls poll_wait twice per fd and corrupts memory
     * sbus audio calls poll_wait twice per fd and corrupts memory
     * IBM MCA driver breaks on Device_Inquiry at boot
     * SHM code corrupts memory (Russell)
     * Linux sends a 1K buffer with SCSI inquiries. The ANSI-SCSI limit
       is 255.
     * Linux uses TEST_UNIT_READY to chck for device presence on a
       PUN/LUN. The INQUIRY is the only valid test allowed by the spec.
     * truncate_inode_pages does unsafe page cache operations
     * Fix the ptrace code to be back compatible and add a new PTRACE
       call set for getting the PIII extra registers
     * EPIC100 fixes
     * Tlan and Epic100 crash under load
     * Fix hpfs_unlink (Al Viro)
     * exec loader permissions
     * Locking on getcwd
     * Loopback fs hangs
     * E820 memory setup causes crashes/corruption on some laptops[**VERY
       NASTY**] (fixed in test5)
     * Debian report that the gcc 2.95 possibly miscompiles fault.c or
       mm/remap.c (Perl script available from Arjan) (fixed in test2 or
       3)
     * Dcache threading (Al Viro)
     * Sockfs races (removing NULL ->i_sb stuf) (Al Viro)
     * Module remove race bug (done: anything with file_operations, fb
       stuff, procfs stuff - Al Viro)
     * DEFXX driver appears broken (reported fixed by Jeff Garzik)
     * Some FB drivers check the A000 area and find it busy then bomb out
       (checked and fixed, reported by Jeff Garzik)
     * Stick lock_kernel() calls around OSS driver with issues to hard to
       fix nicely for 2.4 itself (Alan, fixed)
     * Merge the current Compaq RAID driver into 2.4 (fixed, reported by
       thomas.hiller@sap.com)