LoongArch: ftrace: Add direct call support and code simplification

From:		Youling Tang <tangyouling-AT-loongson.cn>
To:		Huacai Chen <chenhuacai-AT-kernel.org>, Steven Rostedt <rostedt-AT-goodmis.org>, Masami Hiramatsu <mhiramat-AT-kernel.org>, Mark Rutland <mark.rutland-AT-arm.com>
Subject:		[PATCH v2 0/5] LoongArch: ftrace: Add direct call support and code simplification
Date:		Thu, 27 Apr 2023 10:12:27 +0800
Message-ID:		<1682561552-32324-1-git-send-email-tangyouling@loongson.cn>
Cc:		WANG Xuerui <kernel-AT-xen0n.name>, linux-kernel-AT-vger.kernel.org, linux-trace-kernel-AT-vger.kernel.org, loongarch-AT-lists.linux.dev, loongson-kernel-AT-lists.loongnix.cn
Archive-link:		Article

[Patch 1-2]: Fix build errors and simplify code.

[Patch 3-4]:
This series adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS support for LoongArch.
SAMPLE_FTRACE_DIRECT and SAMPLE_FTRACE_DIRECT_MULTI are also included
here as the samples for testing DIRECT_CALLS related interface.

Part of the code refers to arm64 and riscv.

The following tests have been passed in my local 3A5000 machine.
 - ftrace*.ko
 - tools/testing/selftests/ftrace/

eg:
[loongson@linux linux]$ sudo insmod samples/ftrace/ftrace-direct-too.ko
[root@linux linux]# cat /sys/kernel/debug/tracing/trace | tail
           rmmod-4552    [001] .....  3166.654540: 0xffff800002094040: handle mm fault vma=00000000d0dbdb16 address=7ffff2a793e8 flags=254
           rmmod-4552    [001] .....  3166.654550: 0xffff800002094040: handle mm fault vma=0000000047694d8b address=555570700008 flags=255
           rmmod-4552    [001] .....  3166.654557: 0xffff800002094040: handle mm fault vma=00000000d0dbdb16 address=7ffff29e6eb0 flags=254
           rmmod-4552    [001] .....  3166.654561: 0xffff800002094040: handle mm fault vma=00000000d0dbdb16 address=7ffff297d480 flags=254

[Patch 5]: Abstract DYNAMIC_FTRACE_WITH_ARGS accesses.
Note: This patch depends on regs_set_return_value() in the patch
"LoongArch: Add support for function error injection".


Changes in v2:
 - Rewrite commit message.

Qing Zhang (1):
  LoongArch: Abstract DYNAMIC_FTRACE_WITH_ARGS accesses

Youling Tang (4):
  LoongArch: Fix build error if CONFIG_DYNAMIC_FTRACE_WITH_REGS is not
    set
  LoongArch: ftrace: Implement ftrace_find_callable_addr() to simplify
    code
  LoongArch: ftrace: Add direct call support
  LoongArch: ftrace: Add direct call trampoline samples support

 arch/loongarch/Kconfig                      |   3 +
 arch/loongarch/include/asm/ftrace.h         |  37 ++++++
 arch/loongarch/kernel/ftrace_dyn.c          | 132 +++++++++++---------
 arch/loongarch/kernel/mcount_dyn.S          |   7 +-
 samples/ftrace/ftrace-direct-modify.c       |  34 +++++
 samples/ftrace/ftrace-direct-multi-modify.c |  41 ++++++
 samples/ftrace/ftrace-direct-multi.c        |  25 ++++
 samples/ftrace/ftrace-direct-too.c          |  27 ++++
 samples/ftrace/ftrace-direct.c              |  23 ++++
 9 files changed, 266 insertions(+), 63 deletions(-)

-- 
2.37.1