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

From: Masami Hiramatsu
Date: Thu Aug 05 2010 - 08:35:33 EST

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@xxxxxxxxxxx>
Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-doc@xxxxxxxxxxxxxxx

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

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