[RFC PATCH 0/7] kernel-hacking: introduce CONFIG_NO_AUTO_INLINE

[RFC PATCH 0/7] kernel-hacking: introduce CONFIG_NO_AUTO_INLINE

[Chen Linxuan]

This series introduces a new kernel configuration option NO_AUTO_INLINE,
which can be used to disable the automatic inlining of functions.

This will allow the function tracer to trace more functions
because it only traces functions that the compiler has not inlined.

Previous discussions can be found here:
Link: https://lore.kernel.org/all/20181028130945.23581-3-changbin.du@gmail.com/

Chen Linxuan (2):
  drm/i915/pxp: fix undefined reference to
    `intel_pxp_gsccs_is_ready_for_sessions'
  RDMA/hns: initialize db in update_srq_db()

Winston Wen (5):
  nvme: add __always_inline for nvme_pci_npages_prp
  mm: add __always_inline for page_contains_unaccepted
  vfio/virtio: add __always_inline for virtiovf_get_device_config_size
  tpm: add __always_inline for tpm_is_hwrng_enabled
  lib/Kconfig.debug: introduce CONFIG_NO_AUTO_INLINE

 Makefile                                   |  6 ++++++
 drivers/char/tpm/tpm-chip.c                |  2 +-
 drivers/gpu/drm/i915/pxp/intel_pxp_gsccs.h |  8 ++++++--
 drivers/infiniband/hw/hns/hns_roce_hw_v2.c |  2 +-
 drivers/nvme/host/pci.c                    |  2 +-
 drivers/vfio/pci/virtio/legacy_io.c        |  2 +-
 lib/Kconfig.debug                          | 15 +++++++++++++++
 mm/page_alloc.c                            |  2 +-
 8 files changed, 32 insertions(+), 7 deletions(-)

-- 
2.48.1

[RFC PATCH 5/7] RDMA/hns: initialize db in update_srq_db()

[Chen Linxuan]

On x86_64 with gcc version 13.3.0, I compile
drivers/infiniband/hw/hns/hns_roce_hw_v2.c with:

  make defconfig
  ./scripts/kconfig/merge_config.sh .config <(
    echo CONFIG_COMPILE_TEST=y
    echo CONFIG_HNS3=m
    echo CONFIG_INFINIBAND=m
    echo CONFIG_INFINIBAND_HNS_HIP08=m
  )
  make KCFLAGS="-fno-inline-small-functions -fno-inline-functions-called-once" \
    drivers/infiniband/hw/hns/hns_roce_hw_v2.o

Then I get a compile error:

    CALL    scripts/checksyscalls.sh
    DESCEND objtool
    INSTALL libsubcmd_headers
    CC [M]  drivers/infiniband/hw/hns/hns_roce_hw_v2.o
  In file included from drivers/infiniband/hw/hns/hns_roce_hw_v2.c:47:
  drivers/infiniband/hw/hns/hns_roce_hw_v2.c: In function 'update_srq_db':
  drivers/infiniband/hw/hns/hns_roce_common.h:74:17: error: 'db' is used uninitialized [-Werror=uninitialized]
     74 |                 *((__le32 *)_ptr + (field_h) / 32) &=                          \
        |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  drivers/infiniband/hw/hns/hns_roce_common.h:90:17: note: in expansion of macro '_hr_reg_clear'
     90 |                 _hr_reg_clear(ptr, field_type, field_h, field_l);              \
        |                 ^~~~~~~~~~~~~
  drivers/infiniband/hw/hns/hns_roce_common.h:95:39: note: in expansion of macro '_hr_reg_write'
     95 | #define hr_reg_write(ptr, field, val) _hr_reg_write(ptr, field, val)
        |                                       ^~~~~~~~~~~~~
  drivers/infiniband/hw/hns/hns_roce_hw_v2.c:948:9: note: in expansion of macro 'hr_reg_write'
    948 |         hr_reg_write(&db, DB_TAG, srq->srqn);
        |         ^~~~~~~~~~~~
  drivers/infiniband/hw/hns/hns_roce_hw_v2.c:946:31: note: 'db' declared here
    946 |         struct hns_roce_v2_db db;
        |                               ^~
  cc1: all warnings being treated as errors

Signed-off-by: Chen Linxuan <chenlinxuan@uniontech.com>
Co-Developed-by: Winston Wen <wentao@uniontech.com>
Signed-off-by: Winston Wen <wentao@uniontech.com>
---
 drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
index 160e8927d364..7d6c0cfa1ded 100644
--- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
+++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
@@ -943,7 +943,7 @@ static void fill_wqe_idx(struct hns_roce_srq *srq, unsigned int wqe_idx)
 static void update_srq_db(struct hns_roce_srq *srq)
 {
 	struct hns_roce_dev *hr_dev = to_hr_dev(srq->ibsrq.device);
-	struct hns_roce_v2_db db;
+	struct hns_roce_v2_db db = { 0 };
 
 	hr_reg_write(&db, DB_TAG, srq->srqn);
 	hr_reg_write(&db, DB_CMD, HNS_ROCE_V2_SRQ_DB);
-- 
2.48.1

Re: [RFC PATCH 5/7] RDMA/hns: initialize db in update_srq_db()

[Leon Romanovsky]

On Fri, Apr 11, 2025 at 06:54:53PM +0800, Chen Linxuan wrote:
> On x86_64 with gcc version 13.3.0, I compile
> drivers/infiniband/hw/hns/hns_roce_hw_v2.c with:
> 
>   make defconfig
>   ./scripts/kconfig/merge_config.sh .config <(
>     echo CONFIG_COMPILE_TEST=y
>     echo CONFIG_HNS3=m
>     echo CONFIG_INFINIBAND=m
>     echo CONFIG_INFINIBAND_HNS_HIP08=m
>   )
>   make KCFLAGS="-fno-inline-small-functions -fno-inline-functions-called-once" \
>     drivers/infiniband/hw/hns/hns_roce_hw_v2.o
> 
> Then I get a compile error:
> 
>     CALL    scripts/checksyscalls.sh
>     DESCEND objtool
>     INSTALL libsubcmd_headers
>     CC [M]  drivers/infiniband/hw/hns/hns_roce_hw_v2.o
>   In file included from drivers/infiniband/hw/hns/hns_roce_hw_v2.c:47:
>   drivers/infiniband/hw/hns/hns_roce_hw_v2.c: In function 'update_srq_db':
>   drivers/infiniband/hw/hns/hns_roce_common.h:74:17: error: 'db' is used uninitialized [-Werror=uninitialized]
>      74 |                 *((__le32 *)_ptr + (field_h) / 32) &=                          \
>         |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   drivers/infiniband/hw/hns/hns_roce_common.h:90:17: note: in expansion of macro '_hr_reg_clear'
>      90 |                 _hr_reg_clear(ptr, field_type, field_h, field_l);              \
>         |                 ^~~~~~~~~~~~~
>   drivers/infiniband/hw/hns/hns_roce_common.h:95:39: note: in expansion of macro '_hr_reg_write'
>      95 | #define hr_reg_write(ptr, field, val) _hr_reg_write(ptr, field, val)
>         |                                       ^~~~~~~~~~~~~
>   drivers/infiniband/hw/hns/hns_roce_hw_v2.c:948:9: note: in expansion of macro 'hr_reg_write'
>     948 |         hr_reg_write(&db, DB_TAG, srq->srqn);
>         |         ^~~~~~~~~~~~
>   drivers/infiniband/hw/hns/hns_roce_hw_v2.c:946:31: note: 'db' declared here
>     946 |         struct hns_roce_v2_db db;
>         |                               ^~
>   cc1: all warnings being treated as errors
> 
> Signed-off-by: Chen Linxuan <chenlinxuan@uniontech.com>
> Co-Developed-by: Winston Wen <wentao@uniontech.com>
> Signed-off-by: Winston Wen <wentao@uniontech.com>
> ---
>  drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Applied to rdma-next.

Thanks