bbc26e22b8
Add support for vendor hooks. Adds include/trace/hooks
directory for trace definition headers where hooks
can be defined and vendor_hook.c for instantiating
and exporting them for vendor modules.
There are two variants of vendor hooks, both based
on tracepoints:
Normal: this uses the DECLARE_HOOK macro
to create a tracepoint function with the name trace_<name>
where <name> is the unique identifier for the trace.
Restricted: restricted hooks are needed for cases like
scheduler hooks where the attached function must be
called even if the cpu is offline or requires a
non-atomic context. Restricted vendor hooks cannot
be detached, so modules that attach to a restricted
hook can never unload. Also, only 1 attachment is
allowed (any other attempts to attach will fail with
-EBUSY).
For either case, modules attach to the hook by using
register_trace_<name>(func_ptr, NULL).
New hooks should be defined in headers in the
include/trace/hooks/ directory using the
DECLARE_HOOK() or DECLARE_RESTRICTED_HOOK()
macros.
New files added to include/trace/hooks should
be #include'd from drivers/android/vendor_hooks.c.
The EXPORT_TRACEPOINT_SYMBOL_GPL() should be
also added to drivers/android/vendor_hooks.c.
For example, if a new hook, 'android_vh_foo(int &ret)'
is added in do_exit() in exit.c, these changes are
needed:
1. create a new header file include/trace/hooks/foo.h
which contains:
#include <trace/hooks/vendor_hooks.h>
...
DECLARE_HOOK(android_vh_foo,
TP_PROTO(int *retp),
TP_ARGS(retp);
2. in exit.c, add
#include <trace/hooks/foo.h>
...
int ret = 0;
...
android_vh_foo(&ret);
if (ret)
return ret;
...
3. in drivers/android/vendor_hooks.c, add
#include <trace/hooks/foo.h>
...
EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_foo);
The hook can then be attached by adding the registration code
to the module:
#include <trace/hooks/sched.h>
...
static void my_foo(int *retp)
{
*retp = 0;
}
...
rc = register_trace_android_vh_sched_exit(my_foo, NULL);
Bug: 156285741
Bug: 149632552
Signed-off-by: Todd Kjos <tkjos@google.com>
Change-Id: I6a7d1c8919dae91c965e2a0450df50eac2d282db
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
69 lines
2.0 KiB
Plaintext
69 lines
2.0 KiB
Plaintext
# SPDX-License-Identifier: GPL-2.0
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menu "Android"
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config ANDROID
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bool "Android Drivers"
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---help---
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Enable support for various drivers needed on the Android platform
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if ANDROID
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config ANDROID_BINDER_IPC
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bool "Android Binder IPC Driver"
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depends on MMU
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default n
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---help---
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Binder is used in Android for both communication between processes,
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and remote method invocation.
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This means one Android process can call a method/routine in another
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Android process, using Binder to identify, invoke and pass arguments
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between said processes.
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config ANDROID_BINDERFS
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bool "Android Binderfs filesystem"
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depends on ANDROID_BINDER_IPC
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default n
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---help---
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Binderfs is a pseudo-filesystem for the Android Binder IPC driver
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which can be mounted per-ipc namespace allowing to run multiple
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instances of Android.
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Each binderfs mount initially only contains a binder-control device.
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It can be used to dynamically allocate new binder IPC devices via
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ioctls.
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config ANDROID_BINDER_DEVICES
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string "Android Binder devices"
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depends on ANDROID_BINDER_IPC
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default "binder,hwbinder,vndbinder"
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---help---
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Default value for the binder.devices parameter.
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The binder.devices parameter is a comma-separated list of strings
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that specifies the names of the binder device nodes that will be
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created. Each binder device has its own context manager, and is
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therefore logically separated from the other devices.
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config ANDROID_BINDER_IPC_SELFTEST
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bool "Android Binder IPC Driver Selftest"
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depends on ANDROID_BINDER_IPC
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---help---
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This feature allows binder selftest to run.
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Binder selftest checks the allocation and free of binder buffers
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exhaustively with combinations of various buffer sizes and
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alignments.
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config ANDROID_VENDOR_HOOKS
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bool "Android Vendor Hooks"
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depends on TRACEPOINTS
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---help---
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Enable vendor hooks implemented as tracepoints
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Allow vendor modules to attach to tracepoint "hooks" defined via
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DECLARE_HOOK or DECLARE_RESTRICTED_HOOK.
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endif # if ANDROID
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endmenu
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