Re: [PATCH 23/64] drm/amd/pm: Use struct_group() for memcpy() region

Alex Deucher
2021-07-30T02:07:53Z

On Tue, Jul 27, 2021 at 5:17 PM Kees Cook <keescook@chromium.org> wrote:
>
> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memcpy(), memmove(), and memset(), avoid
> intentionally writing across neighboring fields.
>
> Use struct_group() in structs:
> struct atom_smc_dpm_info_v4_5
> struct atom_smc_dpm_info_v4_6
> struct atom_smc_dpm_info_v4_7
> struct atom_smc_dpm_info_v4_10
> PPTable_t
> so the grouped members can be referenced together. This will allow
> memcpy() and sizeof() to more easily reason about sizes, improve
> readability, and avoid future warnings about writing beyond the end of
> the first member.
>
> "pahole" shows no size nor member offset changes to any structs.
> "objdump -d" shows no object code changes.

These headers represent interfaces with firmware running on
microcontrollers, so if the sizes or offsets change that could cause a
problem. That doesn't seem to be the case, but something to keep in
mind. Patch is:
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Feel free to take this through whatever tree makes sense.

Alex

>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
> drivers/gpu/drm/amd/include/atomfirmware.h | 9 ++++++++-
> .../gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h | 3 ++-
> drivers/gpu/drm/amd/pm/inc/smu11_driver_if_navi10.h | 3 ++-
> .../gpu/drm/amd/pm/inc/smu13_driver_if_aldebaran.h | 3 ++-
> drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c | 6 +++---
> drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c | 12 ++++++++----
> drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c | 6 +++---
> 7 files changed, 28 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/include/atomfirmware.h b/drivers/gpu/drm/amd/include/atomfirmware.h
> index 3811e58dd857..694dee9d2691 100644
> --- a/drivers/gpu/drm/amd/include/atomfirmware.h
> +++ b/drivers/gpu/drm/amd/include/atomfirmware.h
> @@ -2081,6 +2081,7 @@ struct atom_smc_dpm_info_v4_5
> {
> struct atom_common_table_header table_header;
> // SECTION: BOARD PARAMETERS
> + struct_group(dpm_info,
> // I2C Control
> struct smudpm_i2c_controller_config_v2 I2cControllers[8];
>
> @@ -2159,7 +2160,7 @@ struct atom_smc_dpm_info_v4_5
> uint32_t MvddRatio; // This is used for MVDD Vid workaround. It has 16 fractional bits (Q16.16)
>
> uint32_t BoardReserved[9];
> -
> + );
> };
>
> struct atom_smc_dpm_info_v4_6
> @@ -2168,6 +2169,7 @@ struct atom_smc_dpm_info_v4_6
> // section: board parameters
> uint32_t i2c_padding[3]; // old i2c control are moved to new area
>
> + struct_group(dpm_info,
> uint16_t maxvoltagestepgfx; // in mv(q2) max voltage step that smu will request. multiple steps are taken if voltage change exceeds this value.
> uint16_t maxvoltagestepsoc; // in mv(q2) max voltage step that smu will request. multiple steps are taken if voltage change exceeds this value.
>
> @@ -2246,12 +2248,14 @@ struct atom_smc_dpm_info_v4_6
>
> // reserved
> uint32_t boardreserved[10];
> + );
> };
>
> struct atom_smc_dpm_info_v4_7
> {
> struct atom_common_table_header table_header;
> // SECTION: BOARD PARAMETERS
> + struct_group(dpm_info,
> // I2C Control
> struct smudpm_i2c_controller_config_v2 I2cControllers[8];
>
> @@ -2348,6 +2352,7 @@ struct atom_smc_dpm_info_v4_7
> uint8_t Padding8_Psi2;
>
> uint32_t BoardReserved[5];
> + );
> };
>
> struct smudpm_i2c_controller_config_v3
> @@ -2478,6 +2483,7 @@ struct atom_smc_dpm_info_v4_10
> struct atom_common_table_header table_header;
>
> // SECTION: BOARD PARAMETERS
> + struct_group(dpm_info,
> // Telemetry Settings
> uint16_t GfxMaxCurrent; // in Amps
> uint8_t GfxOffset; // in Amps
> @@ -2524,6 +2530,7 @@ struct atom_smc_dpm_info_v4_10
> uint16_t spare5;
>
> uint32_t reserved[16];
> + );
> };
>
> /*
> diff --git a/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h b/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h
> index 43d43d6addc0..8093a98800c3 100644
> --- a/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h
> +++ b/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_arcturus.h
> @@ -643,6 +643,7 @@ typedef struct {
> // SECTION: BOARD PARAMETERS
>
> // SVI2 Board Parameters
> + struct_group(v4_6,
> uint16_t MaxVoltageStepGfx; // In mV(Q2) Max voltage step that SMU will request. Multiple steps are taken if voltage change exceeds this value.
> uint16_t MaxVoltageStepSoc; // In mV(Q2) Max voltage step that SMU will request. Multiple steps are taken if voltage change exceeds this value.
>
> @@ -728,10 +729,10 @@ typedef struct {
> uint32_t BoardVoltageCoeffB; // decode by /1000
>
> uint32_t BoardReserved[7];
> + );
>
> // Padding for MMHUB - do not modify this
> uint32_t MmHubPadding[8]; // SMU internal use
> -
> } PPTable_t;
>
> typedef struct {
> diff --git a/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_navi10.h b/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_navi10.h
> index 04752ade1016..0b4e6e907e95 100644
> --- a/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_navi10.h
> +++ b/drivers/gpu/drm/amd/pm/inc/smu11_driver_if_navi10.h
> @@ -725,6 +725,7 @@ typedef struct {
> uint32_t Reserved[8];
>
> // SECTION: BOARD PARAMETERS
> + struct_group(v4,
> // I2C Control
> I2cControllerConfig_t I2cControllers[NUM_I2C_CONTROLLERS];
>
> @@ -809,10 +810,10 @@ typedef struct {
> uint8_t Padding8_Loadline;
>
> uint32_t BoardReserved[8];
> + );
>
> // Padding for MMHUB - do not modify this
> uint32_t MmHubPadding[8]; // SMU internal use
> -
> } PPTable_t;
>
> typedef struct {
> diff --git a/drivers/gpu/drm/amd/pm/inc/smu13_driver_if_aldebaran.h b/drivers/gpu/drm/amd/pm/inc/smu13_driver_if_aldebaran.h
> index a017983ff1fa..5056d3728da8 100644
> --- a/drivers/gpu/drm/amd/pm/inc/smu13_driver_if_aldebaran.h
> +++ b/drivers/gpu/drm/amd/pm/inc/smu13_driver_if_aldebaran.h
> @@ -390,6 +390,7 @@ typedef struct {
> uint32_t spare3[14];
>
> // SECTION: BOARD PARAMETERS
> + struct_group(v4_10,
> // Telemetry Settings
> uint16_t GfxMaxCurrent; // in Amps
> int8_t GfxOffset; // in Amps
> @@ -444,7 +445,7 @@ typedef struct {
>
> //reserved
> uint32_t reserved[14];
> -
> + );
> } PPTable_t;
>
> typedef struct {
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c
> index 6ec8492f71f5..19951399cb33 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c
> @@ -463,11 +463,11 @@ static int arcturus_append_powerplay_table(struct smu_context *smu)
> smc_dpm_table->table_header.format_revision,
> smc_dpm_table->table_header.content_revision);
>
> + BUILD_BUG_ON(sizeof(smc_pptable->v4_6) != sizeof(smc_dpm_table->dpm_info));
> if ((smc_dpm_table->table_header.format_revision == 4) &&
> (smc_dpm_table->table_header.content_revision == 6))
> - memcpy(&smc_pptable->MaxVoltageStepGfx,
> - &smc_dpm_table->maxvoltagestepgfx,
> - sizeof(*smc_dpm_table) - offsetof(struct atom_smc_dpm_info_v4_6, maxvoltagestepgfx));
> + memcpy(&smc_pptable->v4_6, &smc_dpm_table->dpm_info,
> + sizeof(smc_dpm_table->dpm_info));
>
> return 0;
> }
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c
> index 59ea59acfb00..cb6665fbe319 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c
> @@ -431,16 +431,20 @@ static int navi10_append_powerplay_table(struct smu_context *smu)
>
> switch (smc_dpm_table->table_header.content_revision) {
> case 5: /* nv10 and nv14 */
> - memcpy(smc_pptable->I2cControllers, smc_dpm_table->I2cControllers,
> - sizeof(*smc_dpm_table) - sizeof(smc_dpm_table->table_header));
> + BUILD_BUG_ON(sizeof(smc_pptable->v4) !=
> + sizeof(smc_dpm_table->dpm_info));
> + memcpy(&smc_pptable->v4, &smc_dpm_table->dpm_info,
> + sizeof(smc_dpm_table->dpm_info));
> break;
> case 7: /* nv12 */
> ret = amdgpu_atombios_get_data_table(adev, index, NULL, NULL, NULL,
> (uint8_t **)&smc_dpm_table_v4_7);
> if (ret)
> return ret;
> - memcpy(smc_pptable->I2cControllers, smc_dpm_table_v4_7->I2cControllers,
> - sizeof(*smc_dpm_table_v4_7) - sizeof(smc_dpm_table_v4_7->table_header));
> + BUILD_BUG_ON(sizeof(smc_pptable->v4) !=
> + sizeof(smc_dpm_table_v4_7->dpm_info));
> + memcpy(&smc_pptable->v4, &smc_dpm_table_v4_7->dpm_info,
> + sizeof(smc_dpm_table_v4_7->dpm_info));
> break;
> default:
> dev_err(smu->adev->dev, "smc_dpm_info with unsupported content revision %d!\n",
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c
> index 856eeaf293b8..c0645302fa50 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c
> @@ -407,11 +407,11 @@ static int aldebaran_append_powerplay_table(struct smu_context *smu)
> smc_dpm_table->table_header.format_revision,
> smc_dpm_table->table_header.content_revision);
>
> + BUILD_BUG_ON(sizeof(smc_pptable->v4_10) != sizeof(smc_dpm_table->dpm_info));
> if ((smc_dpm_table->table_header.format_revision == 4) &&
> (smc_dpm_table->table_header.content_revision == 10))
> - memcpy(&smc_pptable->GfxMaxCurrent,
> - &smc_dpm_table->GfxMaxCurrent,
> - sizeof(*smc_dpm_table) - offsetof(struct atom_smc_dpm_info_v4_10, GfxMaxCurrent));
> + memcpy(&smc_pptable->v4_10, &smc_dpm_table->dpm_info,
> + sizeof(smc_dpm_table->dpm_info));
> return 0;
> }
>
> --
> 2.30.2
>