36217f676b
[ Upstream commit e4d0ef752081e7aa6ffb7ccac11c499c732a2e05 ]
With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG),
indirect call targets are validated against the expected function
pointer prototype to make sure the call target is valid to help mitigate
ROP attacks. If they are not identical, there is a failure at run time,
which manifests as either a kernel panic or thread getting killed. A
proposed warning in clang aims to catch these at compile time, which
reveals:
drivers/gpu/drm/amd/amdgpu/../pm/swsmu/amdgpu_smu.c:3008:29: error: incompatible function pointer types initializing 'int (*)(void *, uint32_t, long *, uint32_t)' (aka 'int (*)(void *, unsigned int, long *, unsigned int)') with an expression of type 'int (void *, enum PP_OD_DPM_TABLE_COMMAND, long *, uint32_t)' (aka 'int (void *, enum PP_OD_DPM_TABLE_COMMAND, long *, unsigned int)') [-Werror,-Wincompatible-function-pointer-types-strict]
.odn_edit_dpm_table = smu_od_edit_dpm_table,
^~~~~~~~~~~~~~~~~~~~~
1 error generated.
There are only two implementations of ->odn_edit_dpm_table() in 'struct
amd_pm_funcs': smu_od_edit_dpm_table() and pp_odn_edit_dpm_table(). One
has a second parameter type of 'enum PP_OD_DPM_TABLE_COMMAND' and the
other uses 'u32'. Ultimately, smu_od_edit_dpm_table() calls
->od_edit_dpm_table() from 'struct pptable_funcs' and
pp_odn_edit_dpm_table() calls ->odn_edit_dpm_table() from 'struct
pp_hwmgr_func', which both have a second parameter type of 'enum
PP_OD_DPM_TABLE_COMMAND'.
Update the type parameter in both the prototype in 'struct amd_pm_funcs'
and pp_odn_edit_dpm_table() to 'enum PP_OD_DPM_TABLE_COMMAND', which
cleans up the warning.
Link: https://github.com/ClangBuiltLinux/linux/issues/1750
Reported-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.