[PATCH v12 for-next 0/4] riscv: ftrace: Miscellaneous ftrace improvements

[Björn Töpel]

From: Björn Töpel <bjorn at rivosinc.com>

NB! Song told me that he would not have the time work on this series,
so I picked it up.

This series includes a three ftrace improvements for RISC-V:

1. Do not require to run recordmcount at build time (patch 1)
2. Simplification of the function graph functionality (patch 2)
3. Enable DYNAMIC_FTRACE_WITH_DIRECT_CALLS (patch 3 and 4)

The series has been tested on Qemu/rv64 virt/Debian sid with the
following test configs:
  CONFIG_FTRACE_SELFTEST=y
  CONFIG_FTRACE_STARTUP_TEST=y
  CONFIG_SAMPLE_FTRACE_DIRECT=m
  CONFIG_SAMPLE_FTRACE_DIRECT_MULTI=m
  CONFIG_SAMPLE_FTRACE_OPS=m

All tests pass.


Cheers,
Björn


Changes in v12:
- Massaged the commit messages a bit.
- Squashed the samples patches, so that the rv32 support is included
  from the start.
- Minor whitespace changes in the mcount-dyn.S.
- Minor style changes.

Changes in v11:
https://lore.kernel.org/linux-riscv/20230627111612.761164-1-suagrfillet@gmail.com/

- append a patch that makes the DIRECT_CALL samples support RV32I in
  this series fixing the rv32 build failure reported by Palmer
- validated with ftrace boottime selftest and manual sample modules test
  in qemu-system for RV32I and RV64I

Changes in v10:
https://lore.kernel.org/all/20230511093234.3123181-1-suagrfillet@gmail.com/

- add Acked-by from Björn Töpel in patch 2 and patch 4 
- replace `move` with `mv` in patch3 
- prettify patch 2/4 with proper tabs

Changes in v9:
https://lore.kernel.org/linux-riscv/20230510101857.2953955-1-suagrfillet@gmail.com/

1. add Acked-by from Björn Töpel in patch 1

2. rebase patch2/patch3 on Linux v6.4-rc1

  - patch 2: to make the `SAVE_ABI_REGS` configurable, revert the
    modification of mcount-dyn.S from commit (45b32b946a97 "riscv:
entry: Consolidate general regs saving/restoring")

  - patch 3: to pass the trace_selftest, add the implement of
    `ftrace_stub_direct_tramp` from commit (fee86a4ed536 "ftrace:
selftest: remove broken trace_direct_tramp") ; and fixup the context
conflict in Kconfig 

Changes in v8:
https://lore.kernel.org/linux-riscv/20230324033342.3177979-1-suagrfillet@gmail.com/
 - Fix incorrect address values in the 4nd patch 
 - Rebased on v6.3-rc2

Changes in v7:
https://lore.kernel.org/linux-riscv/20230112090603.1295340-1-guoren@kernel.org/
 - Fixup RESTORE_ABI_REGS by remove PT_T0(sp) overwrite.
 - Add FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY [1]
 - Fixup kconfig with HAVE_SAMPLE_FTRACE_DIRECT &
   HAVE_SAMPLE_FTRACE_DIRECT_MULTI

Changes in v6:
https://lore.kernel.org/linux-riscv/20230107133549.4192639-1-guoren@kernel.org/
 - Replace 8 with MCOUNT_INSN_SIZE
 - Replace "REG_L a1, PT_RA(sp)" with "mv a1, ra"
 - Add Evgenii Shatokhin comment

Changes in v5:
https://lore.kernel.org/linux-riscv/20221208091244.203407-1-guoren@kernel.org/
 - Sort Kconfig entries in alphabetical order.

Changes in v4:
https://lore.kernel.org/linux-riscv/20221129033230.255947-1-guoren@kernel.org/
 - Include [3] for maintenance. [Song Shuai]

Changes in V3:
https://lore.kernel.org/linux-riscv/20221123153950.2911981-1-guoren@kernel.org/
 - Include [2] for maintenance. [Song Shuai]

[1]: https://lore.kernel.org/linux-riscv/CAAYs2=j3Eak9vU6xbAw0zPuoh00rh8v5C2U3fePkokZFibWs2g@mail.gmail.com/T/#t
[2]: https://lore.kernel.org/lkml/20221120084230.910152-1-suagrfillet@gmail.com/
[3]: https://lore.kernel.org/linux-riscv/20221123142025.1504030-1-suagrfillet@gmail.com/ 


Song Shuai (4):
  riscv: select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY
  riscv: ftrace: Make function graph use ftrace directly
  riscv: ftrace: Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support
  samples: ftrace: Add RISC-V support for SAMPLE_FTRACE_DIRECT[_MULTI]

 arch/riscv/Kconfig                          |   4 +
 arch/riscv/include/asm/ftrace.h             |  18 +-
 arch/riscv/kernel/ftrace.c                  |  30 ++-
 arch/riscv/kernel/mcount-dyn.S              | 198 ++++++++++++++++----
 samples/ftrace/ftrace-direct-modify.c       |  35 ++++
 samples/ftrace/ftrace-direct-multi-modify.c |  41 ++++
 samples/ftrace/ftrace-direct-multi.c        |  25 +++
 samples/ftrace/ftrace-direct-too.c          |  28 +++
 samples/ftrace/ftrace-direct.c              |  24 +++
 9 files changed, 348 insertions(+), 55 deletions(-)


base-commit: 3ca112b71f35dd5d99fc4571a56b5fc6f0c15814
-- 
2.40.1