[PATCH 1/2] kprobes: Update document about irq disabled state in kprobe handler

[PATCH 1/2] kprobes: Update document about irq disabled state in kprobe handler

[Masami Hiramatsu]

Update kprobes.txt about interrupts disabled state inside
kprobes handlers, because optimized probe/boosted kretprobe
run without disabling interrrupts on x86.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-doc@vger.kernel.org
---

 Documentation/kprobes.txt |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt
index 6653017..4189f01 100644
--- a/Documentation/kprobes.txt
+++ b/Documentation/kprobes.txt
@@ -541,9 +541,11 @@ Kprobes does not use mutexes or allocate memory except during
 registration and unregistration.

 Probe handlers are run with preemption disabled.  Depending on the
-architecture, handlers may also run with interrupts disabled.  In any
-case, your handler should not yield the CPU (e.g., by attempting to
-acquire a semaphore).
+architecture and optimization state, handlers may also run with
+interrupts disabled (e.g., kretprobe handlers and optimized kprobe
+handlers run without interrupt disabled on x86/x86-64).  In any case,
+your handler should not yield the CPU (e.g., by attempting to acquire
+a semaphore).

 Since a return probe is implemented by replacing the return
 address with the trampoline's address, stack backtraces and calls

Re: [PATCH 1/2] kprobes: Update document about irq disabled state in kprobe handler

[Ananth N Mavinakayanahalli]

On Thu, Aug 05, 2010 at 09:35:05PM +0900, Masami Hiramatsu wrote:
> Update kprobes.txt about interrupts disabled state inside
> kprobes handlers, because optimized probe/boosted kretprobe
> run without disabling interrrupts on x86.
> 
> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>

Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>

> Cc: linux-kernel@vger.kernel.org
> Cc: linux-doc@vger.kernel.org
> ---
> 
>  Documentation/kprobes.txt |    8 +++++---
>  1 files changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt
> index 6653017..4189f01 100644
> --- a/Documentation/kprobes.txt
> +++ b/Documentation/kprobes.txt
> @@ -541,9 +541,11 @@ Kprobes does not use mutexes or allocate memory except during
>  registration and unregistration.
> 
>  Probe handlers are run with preemption disabled.  Depending on the
> -architecture, handlers may also run with interrupts disabled.  In any
> -case, your handler should not yield the CPU (e.g., by attempting to
> -acquire a semaphore).
> +architecture and optimization state, handlers may also run with
> +interrupts disabled (e.g., kretprobe handlers and optimized kprobe
> +handlers run without interrupt disabled on x86/x86-64).  In any case,
> +your handler should not yield the CPU (e.g., by attempting to acquire
> +a semaphore).
> 
>  Since a return probe is implemented by replacing the return
>  address with the trampoline's address, stack backtraces and calls
>