[PATCH 0/9] jump label v6

From: Jason Baron
Date: Fri Apr 09 2010 - 15:49:46 EST


Hi,

Refresh of jump labeling patches aginst -tip tree. For bacground see:
http://marc.info/?l=linux-kernel&m=125858436505941&w=2

I believe I've addressed all the reviews from v5.

Changes in v6:

* I've moved Steve Rostedt's 'ftrace_dyn_arch_init()' to alternative.c to
put it into a common area for used by both ftrace and jump labels. By
default we put a 'jmp 5' in the nop slot. Then, when we detect the best
runtime no-op we patch over the 'jmp 5' with the appropriate nop.

* build time sort of the jump label table. The jump label table is more
optimally accessed if the entries are continguous. Sorting the table
accomplishes this. Do the sort at build-time. Adds a '-j' option to
'modpost' which replaces the vmlinux, with a sorted jump label section vmlinux.
I've tested this on x86 with relocatable and it works fine there as well. Note
that I have not sorted the jump label table in modules. This is b/c the jump
label names can be exported by the core kernel, and thus I don't have them
available at buildtime. This could be solved by either finding the correct
ones in the vmlinux, or by embedding the name of the jump label in the module
tables (and not just a pointer), but the module tables tend to be smaller, and
thus there is less value to this kind of change anyway. The kernel continues to
do the sort, just in case, but at least for the vmlinux, this is just a
verfication b/c the jump label table has already been sorted.

* added jump_label_text_reserved(), so that other routines that want to patch
the code, can first verify that they are not stomping on jump label addresses.

thanks,

-Jason

Jason Baron (8):
jump label: base patch
jump label: x86 support
jump label: tracepoint support
jump label: add module support
jump label: move ftrace_dyn_arch_init to common code
jump label: sort jump table at build-time
jump label: initialize workqueue tracepoints *before* they are
registered
jump label: jump_label_text_reserved() to reserve our jump points

Mathieu Desnoyers (1):
jump label: notifier atomic call chain notrace

Makefile | 4 +
arch/x86/include/asm/alternative.h | 14 ++
arch/x86/include/asm/jump_label.h | 27 +++
arch/x86/kernel/Makefile | 2 +-
arch/x86/kernel/alternative.c | 71 ++++++-
arch/x86/kernel/ftrace.c | 70 +------
arch/x86/kernel/jump_label.c | 42 ++++
arch/x86/kernel/kprobes.c | 3 +-
arch/x86/kernel/module.c | 3 +
arch/x86/kernel/ptrace.c | 1 +
arch/x86/kernel/setup.c | 2 +
include/asm-generic/vmlinux.lds.h | 22 ++-
include/linux/jump_label.h | 76 +++++++
include/linux/module.h | 5 +-
include/linux/tracepoint.h | 34 ++--
kernel/Makefile | 2 +-
kernel/jump_label.c | 428 ++++++++++++++++++++++++++++++++++++
kernel/kprobes.c | 3 +-
kernel/module.c | 7 +
kernel/notifier.c | 6 +-
kernel/trace/ftrace.c | 13 +-
kernel/trace/trace_workqueue.c | 10 +-
kernel/tracepoint.c | 8 +
scripts/mod/modpost.c | 69 ++++++-
scripts/mod/modpost.h | 9 +
25 files changed, 816 insertions(+), 115 deletions(-)
create mode 100644 arch/x86/include/asm/jump_label.h
create mode 100644 arch/x86/kernel/jump_label.c
create mode 100644 include/linux/jump_label.h
create mode 100644 kernel/jump_label.c

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