x86/entry: Consolidation part II (syscalls)

Hi!

This is the third version of the syscall entry code consolidation series. V2 can be found here:

https://lore.kernel.org/r/[email protected]

It applies on top of

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/entry

and is also available from git:

git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel entry-v3-part2

The changes vs. V2:

- A massive rework utilizing Peter Zijlstras objtool patches to analyze the new .noinstr.text section:

https://lore.kernel.org/r/[email protected]

Working with this was really helpful as it clearly pin pointed code which calls out of the protected section which is much more efficient and focussed than chasing everything manually.

- Picked up the two RCU patches from Paul for completeness. The bugfix is required anyway and the comments have been really helpful to see where the defense line has to be.

- As the tool flagged KVM as red zone, I looked at the context tracking usage there and it has similar if not worse issues. New set of patches dealing with that.

Please have a close look at the approach and the resulting protected areas.

Known issues:

- The kprobes '.noinstr.text' exclusion currently works only for built in code. Haven't figured out how to to fix that, but I'm sure that Masami knows :)

- The various SANitizers if enabled ruin the picture. Peter and I still have no brilliant idea what to do about that.

Thanks,

tglx

---
 arch/x86/entry/common.c                |  173 ++++++++++++++++++++++++---------
 arch/x86/entry/entry_32.S              |   24 ----
 arch/x86/entry/entry_64.S              |    6 -
 arch/x86/entry/entry_64_compat.S       |   32 ------
 arch/x86/entry/thunk_64.S              |   45 +++++++-
 arch/x86/include/asm/bug.h             |    3 
 arch/x86/include/asm/hardirq.h         |    4 
 arch/x86/include/asm/irqflags.h        |    3 
 arch/x86/include/asm/nospec-branch.h   |    4 
 arch/x86/include/asm/paravirt.h        |    3 
 arch/x86/kvm/svm.c                     |  152 ++++++++++++++++++----------
 arch/x86/kvm/vmx/ops.h                 |    4 
 arch/x86/kvm/vmx/vmenter.S             |    2 
 arch/x86/kvm/vmx/vmx.c                 |   78 +++++++++++---
 arch/x86/kvm/x86.c                     |    4 
 b/include/asm-generic/bug.h            |    9 +
 include/asm-generic/sections.h         |    3 
 include/asm-generic/vmlinux.lds.h      |    4 
 include/linux/compiler.h               |   24 ++++
 include/linux/compiler_types.h         |    4 
 include/linux/context_tracking.h       |   27 +++--
 include/linux/context_tracking_state.h |    6 -
 include/linux/irqflags.h               |    6 +
 include/linux/sched.h                  |    1 
 kernel/context_tracking.c              |   14 +-
 kernel/kprobes.c                       |   11 ++
 kernel/locking/lockdep.c               |   66 +++++++++---
 kernel/panic.c                         |    4 
 kernel/rcu/tree.c                      |   91 +++++++++++------
 kernel/rcu/tree_plugin.h               |    4 
 kernel/rcu/update.c                    |    7 -
 kernel/trace/trace_preemptirq.c        |   25 ++++
 lib/debug_locks.c                      |    2 
 lib/smp_processor_id.c                 |   10 -
 scripts/mod/modpost.c                  |    2 
 35 files changed, 590 insertions(+), 267 deletions(-)