3 Commits

Author SHA1 Message Date
Yang Yingliang
28a03fae6e coresight: dummy: simplify the code with module_platform_driver
The init/exit() of driver only calls platform_driver_register/unregister,
it can be simpilfied with module_platform_driver.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230804092709.1359264-1-yangyingliang@huawei.com
2023-08-04 14:17:30 +01:00
Nathan Chancellor
185891f03f coresight: dummy: Update type of mode parameter in dummy_{sink,source}_enable()
Clang's kernel Control Flow Integrity (kCFI) is a compiler-based
security mitigation that ensures the target of an indirect function call
matches the expected type of the call and trapping if they do not match
exactly. The warning -Wincompatible-function-pointer-types-strict aims
to catch these issues at compile time, which reveals:

  drivers/hwtracing/coresight/coresight-dummy.c:53:12: error: incompatible function pointer types initializing 'int (*)(struct coresight_device *, struct perf_event *, enum cs_mode)' with an expression of type 'int (struct coresight_device *, struct perf_event *, u32)' (aka 'int (struct coresight_device *, struct perf_event *, unsigned int)') [-Werror,-Wincompatible-function-pointer-types-strict]
     53 |         .enable = dummy_source_enable,
        |                   ^~~~~~~~~~~~~~~~~~~
  drivers/hwtracing/coresight/coresight-dummy.c:62:12: error: incompatible function pointer types initializing 'int (*)(struct coresight_device *, enum cs_mode, void *)' with an expression of type 'int (struct coresight_device *, u32, void *)' (aka 'int (struct coresight_device *, unsigned int, void *)') [-Werror,-Wincompatible-function-pointer-types-strict]
     62 |         .enable = dummy_sink_enable,
        |                   ^~~~~~~~~~~~~~~~~
  2 errors generated.

Commit 9fa3682869d4 ("coresight: Use enum type for cs_mode wherever
possible") updated the type of the mode parameter in the prototype but
this driver was not introduced until commit 9d3ba0b6c056 ("Coresight:
Add coresight dummy driver") and 'int' is ABI compatible with 'enum
cs_mode', so there is no warning from regular
-Wincompatible-function-pointer-types.

Adjust the type of the mode parameter in the callback implementations in
the coresight dummy driver to match the prototype, clearing up the
warning and avoiding kCFI failures at runtime.

Fixes: 9d3ba0b6c056 ("Coresight: Add coresight dummy driver")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230616-coresight-dummy-fix-kcfi-warnings-v1-1-c55c64f8f0f5@kernel.org
2023-06-19 10:27:00 +01:00
Hao Zhang
9d3ba0b6c0 Coresight: Add coresight dummy driver
Some Coresight devices that kernel don't have permission to access or
configure. For these devices, a dummy driver is needed to register them as
Coresight devices. The module may also be used to define components that
may not have any programming interfaces, so that paths can be created
in the driver. It provides Coresight API for operations on dummy devices,
such as enabling and disabling them. It also provides the Coresight dummy
sink/source paths for debugging.

Signed-off-by: Hao Zhang <quic_hazha@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230602084149.40031-2-quic_hazha@quicinc.com
2023-06-15 08:50:23 +01:00