[PATCH 00/10] Removal of most do_exit calls

Eric W. Biederman
2021-12-08T20:18:13Z

We have a lot of calls to do_exit that really don't want the semantics
of userspace calling pthread_exit, aka exit(2). Instead the interesting
semantics are those of the current task exiting.

This set of changes removes a dead reference to do_exit on s390,
adds a function make_task_dead and changes all of the oops
implementations to use it, and adds function kthread_exit and
changes all of the kthread exits to use it.

The short term win of this set of changes is being able to move many
sanity checks out of do_exit that are only really interesting during an
oops. Making it easier to see what do_exit is actually doing.

After this set of changes the number there are only about a big screen
full of do_exit calls left. Making future changes much easier to
review.

s390 folks. Can you please verify I read the s390 code correctly when
observing the reference to do_exit really is dead? I would really
appreciate it. I am not very familiar with s390.

This is on top of:
https://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git/ signal-for-v5.17

It is my plan that after these changes are reviewed to apply these
changes into my signal-for-v5.17 branch. After that I can get to
cleaning up where signals, coredumps and the exit code meets.

Eric W. Biederman (10):
exit/s390: Remove dead reference to do_exit from copy_thread
exit: Add and use make_task_dead.
exit: Move oops specific logic from do_exit into make_task_dead
exit: Stop poorly open coding do_task_dead in make_task_dead
exit: Stop exporting do_exit
exit: Implement kthread_exit
exit: Rename module_put_and_exit to module_put_and_kthread_exit
exit: Rename complete_and_exit to kthread_complete_and_exit
kthread: Ensure struct kthread is present for all kthreads
exit/kthread: Move the exit code for kernel threads into struct kthread

arch/alpha/kernel/traps.c | 6 +-
arch/alpha/mm/fault.c | 2 +-
arch/arm/kernel/traps.c | 2 +-
arch/arm/mm/fault.c | 2 +-
arch/arm64/kernel/traps.c | 2 +-
arch/arm64/mm/fault.c | 2 +-
arch/csky/abiv1/alignment.c | 2 +-
arch/csky/kernel/traps.c | 2 +-
arch/csky/mm/fault.c | 2 +-
arch/h8300/kernel/traps.c | 2 +-
arch/h8300/mm/fault.c | 2 +-
arch/hexagon/kernel/traps.c | 2 +-
arch/ia64/kernel/mca_drv.c | 2 +-
arch/ia64/kernel/traps.c | 2 +-
arch/ia64/mm/fault.c | 2 +-
arch/m68k/kernel/traps.c | 2 +-
arch/m68k/mm/fault.c | 2 +-
arch/microblaze/kernel/exceptions.c | 4 +-
arch/mips/kernel/traps.c | 2 +-
arch/nds32/kernel/fpu.c | 2 +-
arch/nds32/kernel/traps.c | 8 +--
arch/nios2/kernel/traps.c | 4 +-
arch/openrisc/kernel/traps.c | 2 +-
arch/parisc/kernel/traps.c | 2 +-
arch/powerpc/kernel/traps.c | 8 +--
arch/riscv/kernel/traps.c | 2 +-
arch/riscv/mm/fault.c | 2 +-
arch/s390/kernel/dumpstack.c | 2 +-
arch/s390/kernel/nmi.c | 2 +-
arch/s390/kernel/process.c | 1 -
arch/sh/kernel/traps.c | 2 +-
arch/sparc/kernel/traps_32.c | 4 +-
arch/sparc/kernel/traps_64.c | 4 +-
arch/x86/entry/entry_32.S | 6 +-
arch/x86/entry/entry_64.S | 6 +-
arch/x86/kernel/dumpstack.c | 4 +-
arch/xtensa/kernel/traps.c | 2 +-
crypto/algboss.c | 4 +-
drivers/net/wireless/rsi/rsi_91x_coex.c | 2 +-
drivers/net/wireless/rsi/rsi_91x_main.c | 2 +-
drivers/net/wireless/rsi/rsi_91x_sdio_ops.c | 2 +-
drivers/net/wireless/rsi/rsi_91x_usb_ops.c | 2 +-
drivers/pnp/pnpbios/core.c | 6 +-
drivers/staging/rts5208/rtsx.c | 16 ++---
drivers/usb/atm/usbatm.c | 2 +-
drivers/usb/gadget/function/f_mass_storage.c | 2 +-
fs/cifs/connect.c | 2 +-
fs/exec.c | 2 +
fs/jffs2/background.c | 2 +-
fs/nfs/callback.c | 4 +-
fs/nfs/nfs4state.c | 2 +-
fs/nfsd/nfssvc.c | 2 +-
include/linux/kernel.h | 1 -
include/linux/kthread.h | 4 +-
include/linux/module.h | 6 +-
include/linux/sched/task.h | 1 +
kernel/exit.c | 88 ++++++++++++++--------------
kernel/fork.c | 4 ++
kernel/futex/core.c | 2 +-
kernel/kexec_core.c | 2 +-
kernel/kthread.c | 78 +++++++++++++++++-------
kernel/module.c | 6 +-
kernel/sched/core.c | 16 ++---
lib/kunit/try-catch.c | 4 +-
net/bluetooth/bnep/core.c | 2 +-
net/bluetooth/cmtp/core.c | 2 +-
net/bluetooth/hidp/core.c | 2 +-
tools/objtool/check.c | 8 ++-
68 files changed, 212 insertions(+), 173 deletions(-)

Eric