From: Todd Kjos tkjos@google.com

aosp inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7YFU9

Reference: https://android.googlesource.com/kernel/common/+/7f62740112ef

-------------------------------------------------

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 Signed-off-by: Todd Kjos tkjos@google.com Change-Id: I6a7d1c8919dae91c965e2a0450df50eac2d282db Conflicts: drivers/android/Kconfig Signed-off-by: Yu Liao liaoyu15@huawei.com --- drivers/android/Kconfig | 9 ++++ drivers/android/Makefile | 1 + drivers/android/vendor_hooks.c | 16 +++++++ include/trace/hooks/vendor_hooks.h | 72 ++++++++++++++++++++++++++++++ 4 files changed, 98 insertions(+) create mode 100644 drivers/android/vendor_hooks.c create mode 100644 include/trace/hooks/vendor_hooks.h

diff --git a/drivers/android/Kconfig b/drivers/android/Kconfig index 07aa8ae0a058..9dbee23aac66 100644 --- a/drivers/android/Kconfig +++ b/drivers/android/Kconfig @@ -47,4 +47,13 @@ config ANDROID_BINDER_IPC_SELFTEST exhaustively with combinations of various buffer sizes and alignments.

+config ANDROID_VENDOR_HOOKS + bool "Android Vendor Hooks" + depends on TRACEPOINTS + ---help--- + Enable vendor hooks implemented as tracepoints + + Allow vendor modules to attach to tracepoint "hooks" defined via + DECLARE_HOOK or DECLARE_RESTRICTED_HOOK. + endmenu diff --git a/drivers/android/Makefile b/drivers/android/Makefile index c9d3d0c99c25..d488047415a0 100644 --- a/drivers/android/Makefile +++ b/drivers/android/Makefile @@ -4,3 +4,4 @@ ccflags-y += -I$(src) # needed for trace events obj-$(CONFIG_ANDROID_BINDERFS) += binderfs.o obj-$(CONFIG_ANDROID_BINDER_IPC) += binder.o binder_alloc.o obj-$(CONFIG_ANDROID_BINDER_IPC_SELFTEST) += binder_alloc_selftest.o +obj-$(CONFIG_ANDROID_VENDOR_HOOKS) += vendor_hooks.o diff --git a/drivers/android/vendor_hooks.c b/drivers/android/vendor_hooks.c new file mode 100644 index 000000000000..4a403a81eed3 --- /dev/null +++ b/drivers/android/vendor_hooks.c @@ -0,0 +1,16 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* vendor_hook.c + * + * Android Vendor Hook Support + * + * Copyright (C) 2020 Google, Inc. + */ + +#define CREATE_TRACE_POINTS +#include <trace/hooks/vendor_hooks.h> + +/* + * Export tracepoints that act as a bare tracehook (ie: have no trace event + * associated with them) to allow external modules to probe them. + */ + diff --git a/include/trace/hooks/vendor_hooks.h b/include/trace/hooks/vendor_hooks.h new file mode 100644 index 000000000000..9d9ae21895dd --- /dev/null +++ b/include/trace/hooks/vendor_hooks.h @@ -0,0 +1,72 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#if !defined(_TRACE_VENDOR_HOOKS_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_VENDOR_HOOKS_H + +#include <linux/tracepoint.h> + +#define DECLARE_HOOK DECLARE_TRACE + +#ifdef TRACE_HEADER_MULTI_READ + +#undef DECLARE_RESTRICTED_HOOK +#define DECLARE_RESTRICTED_HOOK(name, proto, args, cond) \ + DEFINE_TRACE(name) + +/* prevent additional recursion */ +#undef TRACE_HEADER_MULTI_READ +#else /* TRACE_HEADER_MULTI_READ */ + +#define DO_HOOK(tp, proto, args, cond) \ + do { \ + struct tracepoint_func *it_func_ptr; \ + void *it_func; \ + void *__data; \ + \ + if (!(cond)) \ + return; \ + \ + it_func_ptr = (tp)->funcs; \ + if (it_func_ptr) { \ + it_func = (it_func_ptr)->func; \ + __data = (it_func_ptr)->data; \ + ((void(*)(proto))(it_func))(args); \ + WARN_ON(((++it_func_ptr)->func)); \ + } \ + } while (0) + +#define __DECLARE_HOOK(name, proto, args, cond, data_proto, data_args) \ + extern struct tracepoint __tracepoint_##name; \ + static inline void trace_##name(proto) \ + { \ + if (static_key_false(&__tracepoint_##name.key)) \ + DO_HOOK(&__tracepoint_##name, \ + TP_PROTO(data_proto), \ + TP_ARGS(data_args), \ + TP_CONDITION(cond)); \ + } \ + static inline bool \ + trace_##name##_enabled(void) \ + { \ + return static_key_false(&__tracepoint_##name.key); \ + } \ + static inline int \ + register_trace_##name(void (*probe)(data_proto), void *data) \ + { \ + /* only allow a single attachment */ \ + if (trace_##name##_enabled()) \ + return -EBUSY; \ + return tracepoint_probe_register(&__tracepoint_##name, \ + (void *)probe, data); \ + } \ + /* vendor hooks cannot be unregistered */ \ + +#define DECLARE_RESTRICTED_HOOK(name, proto, args, cond) \ + __DECLARE_HOOK(name, PARAMS(proto), PARAMS(args), \ + cond, \ + PARAMS(void *__data, proto), \ + PARAMS(__data, args)) + +#endif /* TRACE_HEADER_MULTI_READ */ + +#endif /* _TRACE_VENDOR_HOOKS_H */

From: Todd Kjos tkjos@google.com

aosp inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7YFU9

Reference: https://android.googlesource.com/kernel/common/+/5e767aa07eea

-------------------------------------------------

commit d25e37d89dd2 ("tracepoint: Optimize using static_call()") refactored tracepoints to use static_call(). Add the same optimization for restricted vendor hooks.

Fixes: d25e37d89dd2 ("tracepoint: Optimize using static_call()") Signed-off-by: Todd Kjos tkjos@google.com Change-Id: I336db7e90b733ac4098ce342001cc31fd215d137 Signed-off-by: Yu Liao liaoyu15@huawei.com --- include/trace/hooks/vendor_hooks.h | 46 ++++++++++++++++++++++++------ 1 file changed, 37 insertions(+), 9 deletions(-)

diff --git a/include/trace/hooks/vendor_hooks.h b/include/trace/hooks/vendor_hooks.h index 8a3fdb9222e5..8a7acb983c67 100644 --- a/include/trace/hooks/vendor_hooks.h +++ b/include/trace/hooks/vendor_hooks.h @@ -13,39 +13,67 @@

#ifdef TRACE_HEADER_MULTI_READ

+#define DEFINE_HOOK_FN(_name, _reg, _unreg, proto, args) \ + static const char __tpstrtab_##_name[] \ + __section(__tracepoints_strings) = #_name; \ + extern struct static_call_key STATIC_CALL_KEY(tp_func_##_name); \ + int __traceiter_##_name(void *__data, proto); \ + struct tracepoint __tracepoint_##_name __used \ + __section(__tracepoints) = { \ + .name = __tpstrtab_##_name, \ + .key = STATIC_KEY_INIT_FALSE, \ + .static_call_key = &STATIC_CALL_KEY(tp_func_##_name), \ + .static_call_tramp = STATIC_CALL_TRAMP_ADDR(tp_func_##_name), \ + .iterator = &__traceiter_##_name, \ + .regfunc = _reg, \ + .unregfunc = _unreg, \ + .funcs = NULL }; \ + __TRACEPOINT_ENTRY(_name); \ + int __traceiter_##_name(void *__data, proto) \ + { \ + struct tracepoint_func *it_func_ptr; \ + void *it_func; \ + \ + it_func_ptr = (&__tracepoint_##_name)->funcs; \ + it_func = (it_func_ptr)->func; \ + __data = (it_func_ptr)->data; \ + ((void(*)(void *, proto))(it_func))(__data, args); \ + WARN_ON(((++it_func_ptr)->func)); \ + return 0; \ + } \ + DEFINE_STATIC_CALL(tp_func_##_name, __traceiter_##_name); + #undef DECLARE_RESTRICTED_HOOK #define DECLARE_RESTRICTED_HOOK(name, proto, args, cond) \ - DEFINE_TRACE(name) - + DEFINE_HOOK_FN(name, NULL, NULL, PARAMS(proto), PARAMS(args))

/* prevent additional recursion */ #undef TRACE_HEADER_MULTI_READ #else /* TRACE_HEADER_MULTI_READ */

-#define DO_HOOK(tp, proto, args, cond) \ +#define DO_HOOK(name, proto, args, cond) \ do { \ struct tracepoint_func *it_func_ptr; \ - void *it_func; \ void *__data; \ \ if (!(cond)) \ return; \ \ - it_func_ptr = (tp)->funcs; \ + it_func_ptr = (&__tracepoint_##name)->funcs; \ if (it_func_ptr) { \ - it_func = (it_func_ptr)->func; \ __data = (it_func_ptr)->data; \ - ((void(*)(proto))(it_func))(args); \ - WARN_ON(((++it_func_ptr)->func)); \ + __DO_TRACE_CALL(name)(args); \ } \ } while (0)

#define __DECLARE_HOOK(name, proto, args, cond, data_proto, data_args) \ + extern int __traceiter_##name(data_proto); \ + DECLARE_STATIC_CALL(tp_func_##name, __traceiter_##name); \ extern struct tracepoint __tracepoint_##name; \ static inline void trace_##name(proto) \ { \ if (static_key_false(&__tracepoint_##name.key)) \ - DO_HOOK(&__tracepoint_##name, \ + DO_HOOK(name, \ TP_PROTO(data_proto), \ TP_ARGS(data_args), \ TP_CONDITION(cond)); \

From: Todd Kjos tkjos@google.com

aosp inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7YFU9

Reference: https://android.googlesource.com/kernel/common/+/943c3b3124d2

-------------------------------------------------

Vendor hooks required explicitly defining macros or inline functions to handle the non-GKI build case (!CONFIG_ANDROID_VENDOR_HOOKS). Added support for generating them automatically so the macros are no longer required.

Both models are now supported so we can transition.

Bug: 177416721 Signed-off-by: Todd Kjos tkjos@google.com Change-Id: I01acc389d315a5d509b0c48116854342a42e1058 Signed-off-by: Yu Liao liaoyu15@huawei.com --- include/trace/hooks/vendor_hooks.h | 9 +++++++++ 1 file changed, 9 insertions(+)

diff --git a/include/trace/hooks/vendor_hooks.h b/include/trace/hooks/vendor_hooks.h index e6cabd366eeb..ef8c95aaebf0 100644 --- a/include/trace/hooks/vendor_hooks.h +++ b/include/trace/hooks/vendor_hooks.h @@ -9,6 +9,8 @@

#include <linux/tracepoint.h>

+#if defined(CONFIG_TRACEPOINTS) && defined(CONFIG_ANDROID_VENDOR_HOOKS) + #define DECLARE_HOOK DECLARE_TRACE

#ifdef TRACE_HEADER_MULTI_READ @@ -102,3 +104,10 @@ PARAMS(__data, args))

#endif /* TRACE_HEADER_MULTI_READ */ + +#else /* !CONFIG_TRACEPOINTS || !CONFIG_ANDROID_VENDOR_HOOKS */ +/* suppress trace hooks */ +#define DECLARE_HOOK DECLARE_EVENT_NOP +#define DECLARE_RESTRICTED_HOOK(name, proto, args, cond) \ + DECLARE_EVENT_NOP(name, PARAMS(proto), PARAMS(args)) +#endif

From: Jialin Zhang zhangjialin11@huawei.com

hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7YFU9

-------------------------------------------------

Make android vendor hooks feature generic.

Signed-off-by: Jialin Zhang zhangjialin11@huawei.com Reviewed-by: Wei Li liwei391@huawei.com Reviewed-by: Xie XiuQi xiexiuqi@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Signed-off-by: Yu Liao liaoyu15@huawei.com --- drivers/Kconfig | 2 ++ drivers/Makefile | 1 + drivers/android/Kconfig | 9 --------- drivers/android/Makefile | 1 - drivers/hooks/Kconfig | 13 +++++++++++++ drivers/hooks/Makefile | 4 ++++ drivers/{android => hooks}/vendor_hooks.c | 2 +- include/trace/hooks/vendor_hooks.h | 4 ++-- 8 files changed, 23 insertions(+), 13 deletions(-) create mode 100644 drivers/hooks/Kconfig create mode 100644 drivers/hooks/Makefile rename drivers/{android => hooks}/vendor_hooks.c (91%)

diff --git a/drivers/Kconfig b/drivers/Kconfig index cc09f02c76d0..07700cc35d16 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -207,6 +207,8 @@ source "drivers/thunderbolt/Kconfig"

source "drivers/android/Kconfig"

+source "drivers/hooks/Kconfig" + source "drivers/gpu/trace/Kconfig"

source "drivers/nvdimm/Kconfig" diff --git a/drivers/Makefile b/drivers/Makefile index 45e1f63f20ad..7c4a51caf4ba 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -181,6 +181,7 @@ obj-y += hwtracing/intel_th/ obj-$(CONFIG_STM) += hwtracing/stm/ obj-$(CONFIG_HISI_PTT) += hwtracing/ptt/ obj-y += android/ +obj-$(CONFIG_VENDOR_HOOKS) += hooks/ obj-$(CONFIG_NVMEM) += nvmem/ obj-$(CONFIG_FPGA) += fpga/ obj-$(CONFIG_FSI) += fsi/ diff --git a/drivers/android/Kconfig b/drivers/android/Kconfig index 9dbee23aac66..07aa8ae0a058 100644 --- a/drivers/android/Kconfig +++ b/drivers/android/Kconfig @@ -47,13 +47,4 @@ config ANDROID_BINDER_IPC_SELFTEST exhaustively with combinations of various buffer sizes and alignments.

-config ANDROID_VENDOR_HOOKS - bool "Android Vendor Hooks" - depends on TRACEPOINTS - ---help--- - Enable vendor hooks implemented as tracepoints - - Allow vendor modules to attach to tracepoint "hooks" defined via - DECLARE_HOOK or DECLARE_RESTRICTED_HOOK. - endmenu diff --git a/drivers/android/Makefile b/drivers/android/Makefile index d488047415a0..c9d3d0c99c25 100644 --- a/drivers/android/Makefile +++ b/drivers/android/Makefile @@ -4,4 +4,3 @@ ccflags-y += -I$(src) # needed for trace events obj-$(CONFIG_ANDROID_BINDERFS) += binderfs.o obj-$(CONFIG_ANDROID_BINDER_IPC) += binder.o binder_alloc.o obj-$(CONFIG_ANDROID_BINDER_IPC_SELFTEST) += binder_alloc_selftest.o -obj-$(CONFIG_ANDROID_VENDOR_HOOKS) += vendor_hooks.o diff --git a/drivers/hooks/Kconfig b/drivers/hooks/Kconfig new file mode 100644 index 000000000000..1c0e33ef9a56 --- /dev/null +++ b/drivers/hooks/Kconfig @@ -0,0 +1,13 @@ +# SPDX-License-Identifier: GPL-2.0 +menu "Vendor Hooks" + +config VENDOR_HOOKS + bool "Vendor Hooks" + depends on TRACEPOINTS + help + Enable vendor hooks implemented as tracepoints + + Allow vendor modules to attach to tracepoint "hooks" defined via + DECLARE_HOOK or DECLARE_RESTRICTED_HOOK. + +endmenu diff --git a/drivers/hooks/Makefile b/drivers/hooks/Makefile new file mode 100644 index 000000000000..159230826966 --- /dev/null +++ b/drivers/hooks/Makefile @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-only +ccflags-y += -I$(src) # needed for trace events + +obj-$(CONFIG_VENDOR_HOOKS) += vendor_hooks.o diff --git a/drivers/android/vendor_hooks.c b/drivers/hooks/vendor_hooks.c similarity index 91% rename from drivers/android/vendor_hooks.c rename to drivers/hooks/vendor_hooks.c index 4a403a81eed3..359989d1bb32 100644 --- a/drivers/android/vendor_hooks.c +++ b/drivers/hooks/vendor_hooks.c @@ -1,7 +1,7 @@ // SPDX-License-Identifier: GPL-2.0-only /* vendor_hook.c * - * Android Vendor Hook Support + * Vendor Hook Support * * Copyright (C) 2020 Google, Inc. */ diff --git a/include/trace/hooks/vendor_hooks.h b/include/trace/hooks/vendor_hooks.h index 3661e5056519..ab8864da66d8 100644 --- a/include/trace/hooks/vendor_hooks.h +++ b/include/trace/hooks/vendor_hooks.h @@ -9,7 +9,7 @@

#include <linux/tracepoint.h>

-#if defined(CONFIG_TRACEPOINTS) && defined(CONFIG_ANDROID_VENDOR_HOOKS) +#if defined(CONFIG_TRACEPOINTS) && defined(CONFIG_VENDOR_HOOKS)

#define DECLARE_HOOK DECLARE_TRACE

@@ -111,7 +111,7 @@

#endif /* TRACE_HEADER_MULTI_READ */

-#else /* !CONFIG_TRACEPOINTS || !CONFIG_ANDROID_VENDOR_HOOKS */ +#else /* !CONFIG_TRACEPOINTS || !CONFIG_VENDOR_HOOKS */ /* suppress trace hooks */ #define DECLARE_HOOK DECLARE_EVENT_NOP #define DECLARE_RESTRICTED_HOOK(name, proto, args, cond) \