Merge branch 'iop-raid6' into async-tx-next

[pandora-kernel.git] / Documentation / kprobes.txt

diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt
index 48b3de9..1e7a769 100644 (file)
--- a/Documentation/kprobes.txt
+++ b/Documentation/kprobes.txt
@@ -212,7 +212,9 @@ hit, Kprobes calls kp->pre_handler.  After the probed instruction
 is single-stepped, Kprobe calls kp->post_handler.  If a fault
 occurs during execution of kp->pre_handler or kp->post_handler,
 or during single-stepping of the probed instruction, Kprobes calls
 is single-stepped, Kprobe calls kp->post_handler.  If a fault
 occurs during execution of kp->pre_handler or kp->post_handler,
 or during single-stepping of the probed instruction, Kprobes calls

-kp->fault_handler.  Any or all handlers can be NULL.
+kp->fault_handler.  Any or all handlers can be NULL. If kp->flags
+is set KPROBE_FLAG_DISABLED, that kp will be registered but disabled,
+so, it's handlers aren't hit until calling enable_kprobe(kp).

 
 NOTE:
 1. With the introduction of the "symbol_name" field to struct kprobe,
 
 NOTE:
 1. With the introduction of the "symbol_name" field to struct kprobe,


@@ -363,6 +365,26 @@ probes) in the specified array, they clear the addr field of those
 incorrect probes. However, other probes in the array are
 unregistered correctly.
 
 incorrect probes. However, other probes in the array are
 unregistered correctly.
 

+4.7 disable_*probe
+
+#include <linux/kprobes.h>
+int disable_kprobe(struct kprobe *kp);
+int disable_kretprobe(struct kretprobe *rp);
+int disable_jprobe(struct jprobe *jp);
+
+Temporarily disables the specified *probe. You can enable it again by using
+enable_*probe(). You must specify the probe which has been registered.
+
+4.8 enable_*probe
+
+#include <linux/kprobes.h>
+int enable_kprobe(struct kprobe *kp);
+int enable_kretprobe(struct kretprobe *rp);
+int enable_jprobe(struct jprobe *jp);
+
+Enables *probe which has been disabled by disable_*probe(). You must specify
+the probe which has been registered.
+

 5. Kprobes Features and Limitations
 
 Kprobes allows multiple probes at the same address.  Currently,
 5. Kprobes Features and Limitations
 
 Kprobes allows multiple probes at the same address.  Currently,


@@ -500,10 +522,14 @@ the probe. If the probed function belongs to a module, the module name
 is also specified. Following columns show probe status. If the probe is on
 a virtual address that is no longer valid (module init sections, module
 virtual addresses that correspond to modules that've been unloaded),
 is also specified. Following columns show probe status. If the probe is on
 a virtual address that is no longer valid (module init sections, module
 virtual addresses that correspond to modules that've been unloaded),

-such probes are marked with [GONE].
+such probes are marked with [GONE]. If the probe is temporarily disabled,
+such probes are marked with [DISABLED].

 
 

-/debug/kprobes/enabled: Turn kprobes ON/OFF
+/debug/kprobes/enabled: Turn kprobes ON/OFF forcibly.

 
 

-Provides a knob to globally turn registered kprobes ON or OFF. By default,
-all kprobes are enabled. By echoing "0" to this file, all registered probes
-will be disarmed, till such time a "1" is echoed to this file.
+Provides a knob to globally and forcibly turn registered kprobes ON or OFF.
+By default, all kprobes are enabled. By echoing "0" to this file, all
+registered probes will be disarmed, till such time a "1" is echoed to this
+file. Note that this knob just disarms and arms all kprobes and doesn't
+change each probe's disabling state. This means that disabled kprobes (marked
+[DISABLED]) will be not enabled if you turn ON all kprobes by this knob.