[PATCH -tip 0/4] Text edit lock and atomic text_poke()

[Masami Hiramatsu <mhiramat@redhat.com>]

Hi,

Here is a series of patches which introduce text_mutex for protecting
editing kernel text from each other subsystems, and make text_poke()
atomic by using fixmap.

BTW,

> Paravirt and alternatives are always done when SMP is inactive, so there is no
> need to use locks.

Mathieu, I'm not sure that means. alternatives will be called from module
init code and other place where the system has already been running multi-
-threads(and they use smp_alt mutex). So, is it possible that those functions
will sleep or yield to another process?

Anyway, I added a new patch which locks text_mutex in alternative_smp_*.

Thank you,

 arch/x86/include/asm/fixmap.h |    2 ++
 arch/x86/kernel/alternative.c |   29 ++++++++++++++++++++---------
 include/linux/memory.h        |    6 ++++++
 kernel/kprobes.c              |   15 +++++++++++++--
 mm/memory.c                   |    9 +++++++++
 5 files changed, 50 insertions(+), 11 deletions(-)

-- 
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division

e-mail: mhiramat@redhat.com