From: Nathan Chancellor nathan@kernel.org
[ 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 --- drivers/gpu/drm/amd/include/kgd_pp_interface.h | 3 ++- drivers/gpu/drm/amd/pm/powerplay/amd_powerplay.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/include/kgd_pp_interface.h b/drivers/gpu/drm/amd/include/kgd_pp_interface.h index 94132c70d7af..5e8876ad1a1b 100644 --- a/drivers/gpu/drm/amd/include/kgd_pp_interface.h +++ b/drivers/gpu/drm/amd/include/kgd_pp_interface.h @@ -282,7 +282,8 @@ struct amd_pm_funcs { int (*get_power_profile_mode)(void *handle, char *buf); int (*set_power_profile_mode)(void *handle, long *input, uint32_t size); int (*set_fine_grain_clk_vol)(void *handle, uint32_t type, long *input, uint32_t size); - int (*odn_edit_dpm_table)(void *handle, uint32_t type, long *input, uint32_t size); + int (*odn_edit_dpm_table)(void *handle, enum PP_OD_DPM_TABLE_COMMAND type, + long *input, uint32_t size); int (*set_mp1_state)(void *handle, enum pp_mp1_state mp1_state); int (*smu_i2c_bus_access)(void *handle, bool acquire); /* export to DC */ diff --git a/drivers/gpu/drm/amd/pm/powerplay/amd_powerplay.c b/drivers/gpu/drm/amd/pm/powerplay/amd_powerplay.c index eab9768029c1..a98ea29b2fd5 100644 --- a/drivers/gpu/drm/amd/pm/powerplay/amd_powerplay.c +++ b/drivers/gpu/drm/amd/pm/powerplay/amd_powerplay.c @@ -924,7 +924,8 @@ static int pp_set_fine_grain_clk_vol(void *handle, uint32_t type, long *input, u return hwmgr->hwmgr_func->set_fine_grain_clk_vol(hwmgr, type, input, size); }
-static int pp_odn_edit_dpm_table(void *handle, uint32_t type, long *input, uint32_t size) +static int pp_odn_edit_dpm_table(void *handle, enum PP_OD_DPM_TABLE_COMMAND type, + long *input, uint32_t size) { struct pp_hwmgr *hwmgr = handle;